Difference between revisions of "Team:Stuttgart/Results"

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  <section class="hero is-primary">
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     <div class="hero-body">
 
     <div class="hero-body">
      <div class="container has-text-centered">
+
        <div class="container has-text-centered">
        <h2 class="subtitle">
+
            <h2 class="subtitle">
          Project
+
                Project
        </h2>
+
            </h2>
        <h1 class="title">
+
            <h1 class="title">
          Results
+
                Results
        </h1>
+
            </h1>
      </div>
+
        </div>
 
     </div>
 
     </div>
  </section>
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</section>
  
  <div style="padding: 4rem 0;" class="container">
+
<div style="padding: 4rem 0;" class="container">
 
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+
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+
            <aside class="menu sticky">
          <p class="menu-label">
+
                <p class="menu-label">
            Vibrio
+
                    Vibrio
          </p>
+
                </p>
          <ul class="menu-list">
+
                <ul class="menu-list">
            <li><a href="#qPCR">qPCR</a></li>
+
                    <li><a href="#qPCR">qPCR</a></li>
            <li><a href="#cloningtRNA">Cloning of tRNA fragments</a></li>
+
                    <li><a href="#cloningtRNA">Cloning of tRNA fragments</a></li>
          </ul>
+
                </ul>
          <p class="menu-label">
+
                <p class="menu-label">
            Algae
+
                    Algae
          </p>
+
                </p>
  
          <ul class="menu-list">
+
                <ul class="menu-list">
            <li><a href="#algae-media-based">Media based on algae</a></li>
+
                    <li><a href="#algae-media-based">Media based on algae</a></li>
            <li>
+
                    <li>
              <a href="#autolysis"
+
                        <a href="#autolysis"
                >Autolysis in combination <br />
+
                        >Autolysis in combination <br/>
                with bead-milling Results</a
+
                            with bead-milling Results</a
              >
+
                        >
            </li>
+
                    </li>
            <li><a href="#cdwcorrelation">CDW correlation</a></li>
+
                    <li><a href="#cdwcorrelation">CDW correlation</a></li>
            <li>
+
                    <li>
              <a href="#cdwodcorrelation"
+
                        <a href="#cdwodcorrelation">CDW-OD correlation by dilution Results</a>
                >CDW-OD correlation by dilution Results</a
+
                    </li>
              >
+
                </ul>
            </li>
+
            </aside>
          </ul>
+
        </aside>
+
      </div>
+
      <div class="column">
+
        <div id="qPCR" class="section-container">
+
          <h2 class="title is-3">
+
            qRT-PCR for the relative quantification of specific tRNA-species
+
          </h2>
+
          <p>
+
            Alongside with the generation of a climate-friendly medium, the goal
+
            of our project PhyCoVi was to optimize the strain
+
            <em>Vibrio natriegens</em> for a potential use in the biotech
+
            industry. The optimization is performed on the genomic level to
+
            increase the intracellular availability of tRNA species. As a
+
            result, the strain&rsquo;s performance to express heterologous
+
            proteins is enhanced.
+
          </p>
+
          <br />
+
          <p>
+
            A method needs to be developed to quantify individual tRNA species
+
            specifically to prove the increased expression not only on the
+
            protein level. &nbsp;Multiple methods can be found to quantify
+
            non-coding RNA <sup>1, 2</sup> or total tRNA concentration<sup>
+
              3, 4</sup
+
            >. Whereas finding a well-established method to quantify single tRNA
+
            species specifically is in vain. The only method paper was published
+
            in the journal &ldquo;RNA biology&rdquo; in 2015 by Honda
+
            <em>et al.</em>: &ldquo;Four-leaf clover qRT-PCR: A convenient
+
            method for selective quantification of mature tRNA&rdquo;
+
            <sup>5</sup>. The authors of this paper removed the amino acid at
+
            the 3&rsquo; end followed by hybridization and ligation with a
+
            DNA/RNA hybrid stem loop creating a &ldquo;four-leaf clover&rdquo;
+
            shaped appearance of the tRNA ligation product. The stem loop
+
            adaptor contained a TaqMan probe binding site. During the qPCR the
+
            TaqMan probe was cut by exonuclease function of the used polymerase
+
            resulting in emission of fluorescence.
+
          </p>
+
          <br />
+
          <p>
+
            Building on the work of Honda <em>et al.</em> we developed a new and
+
            simplified method for relative quantification of specific tRNA
+
            species without the necessity of TaqMan probes. Instead using a
+
            DNA/RNA hybrid stem loop we used a linear DNA/RNA construct as
+
            adaptor.
+
          </p>
+
          <br />
+
          <p>
+
            The first step is to isolate RNA with a length of &lt; 200 nt from
+
            cultured <em>V. natriegens</em> cells. Then, the amino acid bound to
+
            the 3&rsquo; end needs to be removed by a deacylation reaction. This
+
            results in a sticky end, where a linear RNA/DNA hybrid adaptor can
+
            be ligated, which is complementary to the 3&rsquo; end overhang.
+
            Although different tRNAs show differences in length and sequence,
+
            the last three nucleotides at the 3&rsquo; end are the same for all
+
            tRNA species. The ligated adaptor contains a binding site for the
+
            forward-primer, which is identical for all tRNAs (unspecific
+
            primer). We used T4-RNA-ligase 2 that requires ATP. For this reason,
+
            a polynucleotide kinase was necessary to carry out a phosphorylation
+
            reaction at the 5&rsquo; end.
+
          </p>
+
          <br />
+
          <p>
+
            To amplify single tRNA species specifically, we distinguished
+
            between two options. First option was using the specific tRNA primer
+
            in a reverse transcription to convert the whole tRNA pool to cDNA.
+
            Following RNase H digestion results in pure cDNA of the desired tRNA
+
            species.
+
          </p>
+
          <p>
+
            Later the desired tRNA species is amplified during a qPCR by using
+
            the specific reverse primer and the unspecific adaptor primer.
+
          </p>
+
          <p>
+
            During qPCR a DNA-intercalating fluorescence dye (Green DNA dye)
+
            allows for relative quantification: Green DNA dye binds to double
+
            stranded DNA and absorbs blue light and emits green light. The more
+
            double stranded DNA is generated, the higher the resulting
+
            fluorescence. And the higher the concentration of the template in
+
            the sample the faster the fluorescence exceeds the threshold. The
+
            number of cycles at which this happens is called the threshold cycle
+
            (C<sub>t</sub>). (e.g. if sample A showed a C<sub>t</sub> of 8 and
+
            sample B showed a C<sub>t</sub> of 11, sample A contained
+
            2<sup>3</sup>&nbsp;= 8 times more template.)
+
          </p>
+
          <br />
+
          <p>
+
            After running a DNA gel, we noticed that the obtained amplification
+
            products did not show the expected length. This may have been a
+
            result of distinct secondary structures of the tRNA species: the
+
            reverse transcription reaction was performed at 42 &deg;C which is
+
            the enzyme&rsquo;s optimum working temperature. However, this
+
            temperature is not high enough to prevent secondary structures or to
+
            break them up. Therefore, areas with secondary structures may have
+
            been inaccessible for the reverse transcriptase resulting in shorter
+
            cDNA fragments.
+
          </p>
+
          <br />
+
          <p>
+
            For this reason, we tested a second option to amplify single tRNA
+
            species specifically. A modified polymerase together with the
+
            specific reverse primer can be used to amplify the desired tRNA
+
            species using RNA as a template. This modified polymerase works at
+
            temperatures around 65 &deg;C and can use both RNA and DNA as a
+
            template. The reverse transcription reaction is thus not needed as a
+
            consecutive step anymore. Moreover, the modified enzyme creates the
+
            specific cDNA from RNA directly and the high temperature prevents
+
            secondary structures. The relative quantification based on C<sub
+
              >t </sub
+
            >values is the same as in the option described before.
+
          </p>
+
          <br /><br />
+
          <div class="notification">
+
            <h3 class="title is-5">References</h3>
+
            <ol>
+
              <li>
+
                I. A. Babarinde, Y. Li, A. P. Hutchins (2019) Computational
+
                Methods for Mapping, Assembly and Quantification for Coding and
+
                Non-coding Transcripts, Computational and Structural
+
                Biotechnology Journal, Vol. 17, pp 628-637
+
              </li>
+
            </ol>
+
            <p>&nbsp;</p>
+
            <ol start="2">
+
              <li>
+
                D. Jacob, K. Th&uuml;ring, A. Galliot, V. Marchand, A. Galvanin,
+
                A. Ciftci, K. Scharmann, M. Stock, J.‐Y. Roignant, S.A. Leidel,
+
                Y. Motorin, R. Schaffrath, R. Klassen, M. Helm (2019) Absolute
+
                Quantification of Noncoding RNA by Microscale Thermophoresis,
+
                Angewandte Chemie International Edition, Vol. 58, pp 9565
+
                &ndash; 9569
+
              </li>
+
            </ol>
+
            <p>&nbsp;</p>
+
            <ol start="3">
+
              <li>
+
                T. S. Stenum, M. A. S&oslash;rensen, S. L. Svenningsen (2017)
+
                Quantification of the Abundance and Charging Levels of Transfer
+
                RNAs in&nbsp;<em>Escherichia coli</em>.&nbsp;Journal of Visual
+
                Experiments, Issue 126, e56212
+
              </li>
+
            </ol>
+
            <p>&nbsp;</p>
+
            <ol start="4">
+
              <li>
+
                Y. Guo, A. Bosompem, S.Mohan, B. Erdogan, F.Ye, K. C. Vickers,
+
                Q. Sheng, S. Zhao, C. Li, P.-F. Su, M. Jagasia, S. A.
+
                Strickland, E. A. Griffiths, A. S. Kim (2015) Transfer RNA
+
                detection by small RNA deep sequencing and disease association
+
                with myelodysplastic syndromes, BMC Genomics, 16:727
+
              </li>
+
            </ol>
+
            <p>&nbsp;</p>
+
            <ol start="5">
+
              <li>
+
                S. Honda, M. Shigematsu, K. Morichika, A. G. Telonis, Y. Kirino
+
                (2015) Four-leaf clover qRT-PCR: A convenient method for
+
                selective quantification of mature tRNA, RNA Biology, Vol. 12,
+
                pp 501 &ndash; 508
+
              </li>
+
            </ol>
+
          </div>
+
 
         </div>
 
         </div>
         <div id="cloningtRNA" class="section-container">
+
         <div class="column">
          <h2 class="title is-3">Cloning of tRNA fragments into pSB1C3</h2>
+
            <div id="qPCR" class="section-container">
          <div class="columns">
+
                <h2 class="title is-3">
            <div class="column">
+
                    qRT-PCR for the relative quantification of specific tRNA-species
              <p>
+
                </h2>
                The tRNA fragments were synthesized by IDT and amplified by PCR
+
                <p>
                according to the PCR protocol (<a
+
                    Alongside with the generation of a climate-friendly medium, the goal of our project PhyCoVi was to
                  href="https://2019.igem.org/wiki/images/f/f4/T--Stuttgart--Protocol_PCR.pdf"
+
                    optimize
                  >Protocol_PCR.pdf</a
+
                    the strain
                >). The amplified tRNA fragments were validated via agarose gel
+
                    <em>Vibrio natriegens</em> for a potential use in the biotech industry. The optimization is
                electrophoresis (<a
+
                    performed on the
                  href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
+
                    genomic level to increase the intracellular availability of tRNA species. As a result, the strain&rsquo;s
                  >Stuttgart--Protocol_Agarose_Gel.pdf</a
+
                    performance to express heterologous proteins is enhanced.
                >). Looking at Figure 1 all tRNA fragments showed a clear band
+
                </p>
                at the desired height.
+
                <br/>
              </p>
+
                <p>
              <img
+
                    A method needs to be developed to quantify individual tRNA species specifically to prove the
                style="display: block; max-width: 500px; margin: 0 auto;"
+
                    increased
                src="https://2019.igem.org/wiki/images/thumb/8/86/T--Stuttgart--Amplified_tRNA_fragments.png/592px-T--Stuttgart--Amplified_tRNA_fragments.png"
+
                    expression not only on the protein level. &nbsp;Multiple methods can be found to quantify non-coding
              />
+
                    RNA
              <small>
+
                    <sup>1, 2</sup> or total tRNA concentration<sup> 3, 4</sup>. Whereas finding a well-established
                Figure 1: Amplified tRNA fragments. The tRNA fragments AGA, CGC,
+
                    method to
                TGC, TCC and AGG were amplified via PCR. The PCR products were
+
                    quantify single tRNA species specifically is in vain. The only method paper was published in the
                separated by agarose gel electrophoresis. A 2% agarose gel was
+
                    journal
                prepared and 10 &micro;L were loaded for each probe ((1): AGA,
+
                    &ldquo;RNA biology&rdquo; in 2015 by Honda <em>et al.</em>: &ldquo;Four-leaf clover qRT-PCR: A
                (2): CGC, (3): TGC, (4): TCC, (5): AGG). 3 &micro;L of
+
                    convenient
                Hyberladder 1 kb Bioline were loaded as a marker (M). The gel
+
                    method for selective quantification of mature tRNA&rdquo; <sup>5</sup>. The authors of this paper
                was run at 90 V for 1 hour and stained using MidoriGreen.
+
                    removed
              </small>
+
                    the amino acid at the 3&rsquo; end followed by hybridization and ligation with a DNA/RNA hybrid stem
              <br />
+
                    loop
              <br />
+
                    creating a &ldquo;four-leaf clover&rdquo; shaped appearance of the tRNA ligation product. The stem
              <p>
+
                    loop
                In a first step, the tRNA fragments were cloned into the pSB1C3
+
                    adaptor contained a TaqMan probe binding site. During the qPCR the TaqMan probe was cut by
                vector. The pSB1C3 and the tRNA fragments AGA, AGG, CGG, TGC,
+
                    exonuclease
                TCC and a combined tRNA fragment containing all 5 tRNAs were
+
                    function of the used polymerase resulting in emission of fluorescence.
                digested using the restriction enzymes XbaI and SpeI. <br />
+
                </p>
                After purification, (<a
+
                <br/>
                  href="https://2019.igem.org/wiki/images/3/3f/T--Stuttgart--Protocol_Clean_and_Concentrate.pdf"
+
                <p>
                >
+
                    Building on the work of Honda <em>et al.</em> we developed a new and simplified method for relative
                  Protocol_Clean_and_Concentrate.pdf</a
+
                    quantification of specific tRNA species without the necessity of TaqMan probes. Instead using a
                >) the digested fragments were ligated using the T4 DNA ligase
+
                    DNA/RNA
                (see
+
                    hybrid stem loop we used a linear DNA/RNA construct as adaptor.
                <a
+
                </p>
                  href="https://2019.igem.org/wiki/images/0/03/T--Stuttgart--Protocol_BioBrick_Cloning.pdf"
+
                <br/>
                >
+
                <p>
                  Protocol_BioBrick_Cloning.pdf</a
+
                    The first step is to isolate RNA with a length of &lt; 200 nt from cultured <em>V. natriegens</em>
                >). The ligated DNA fragments were transformed into DH5&alpha;
+
                    cells.
                (<a
+
                    Then, the amino acid bound to the 3&rsquo; end needs to be removed by a deacylation reaction. This
                  href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf"
+
                    results
                >
+
                    in a sticky end, where a linear RNA/DNA hybrid adaptor can be ligated, which is complementary to the
                  Protocol_Transformation.pdf</a
+
                    3&rsquo; end overhang. Although different tRNAs show differences in length and sequence, the last
                >). The plasmid obtained from the colonies (<a
+
                    three
                  href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
+
                    nucleotides at the 3&rsquo; end are the same for all tRNA species. The ligated adaptor contains a
                >
+
                    binding
                  Protocol_Plasmid_Preparation.pdf</a
+
                    site for the forward-primer, which is identical for all tRNAs (unspecific primer). We used
                >) was digested with XbaI to gain linear Plasmid and separated
+
                    T4-RNA-ligase 2
                by agarose gel electrophoresis (<a
+
                    that requires ATP. For this reason, a polynucleotide kinase was necessary to carry out a
                  href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
+
                    phosphorylation
                >
+
                    reaction at the 5&rsquo; end.
                  Protocol_Agarose_Gel.pdf</a
+
                </p>
                >). Looking at Figure 2 the obtained plasmids showed no insert,
+
                <br/>
                only pSB1C3. Also visible is, that despite the digestion,
+
                <p>
                circular, supercoiled and open circular structures of the
+
                    To amplify single tRNA species specifically, we distinguished between two options. First option was
                plasmid are still present. This indicates inefficient digestion
+
                    using
                by the restriction enzymes.
+
                    the specific tRNA primer in a reverse transcription to convert the whole tRNA pool to cDNA.
              </p>
+
                    Following RNase
              <br />
+
                    H digestion results in pure cDNA of the desired tRNA species.
              <img
+
                </p>
                style="display: block; max-width: 500px; margin: 0 auto;"
+
                <p>
                src="https://2019.igem.org/wiki/images/thumb/8/8f/T--Stuttgart--Cloning_of_tRNA_fragments_into_pSB1C3.png/722px-T--Stuttgart--Cloning_of_tRNA_fragments_into_pSB1C3.png"
+
                    Later the desired tRNA species is amplified during a qPCR by using the specific reverse primer and
              />
+
                    the
              <small>
+
                    unspecific adaptor primer.
                Figure 2 - Cloning of tRNA fragments into pSB1C3. The pSB1C3 and
+
                </p>
                the tRNA fragments were digested using the restriction enzymes
+
                <p>
                XbaI and SpeI. After purification, the digested fragments were
+
                    During qPCR a DNA-intercalating fluorescence dye (Green DNA dye) allows for relative quantification:
                ligated using the T4 DNA ligase. The ligated DNA fragments were
+
                    Green
                transformed into DH5&alpha; and subsequently prepared. The
+
                    DNA dye binds to double stranded DNA and absorbs blue light and emits green light. The more double
                obtained plasmids were digested with XbaI before the agarose gel
+
                    stranded
                electrophoresis. A 1% agarose gel was prepared and 10 &micro;L
+
                    DNA is generated, the higher the resulting fluorescence. And the higher the concentration of the
                were loaded for each probe ((1): AGA, (2): AGG, (3): CGG, (4):
+
                    template in
                TGC, (5): TCC, (6): Combined tRNA fragment). As a control (C)
+
                    the sample the faster the fluorescence exceeds the threshold. The number of cycles at which this
                the linear pSB1C3 was loaded. 3 &micro;L of GeneRuler, 1kb Plus
+
                    happens is
                DNA Ladder was loaded as a marker (M). The gel was run at 90 V
+
                    called the threshold cycle (C<sub>t</sub>). (e.g. if sample A showed a C<sub>t</sub> of 8 and sample
                for 1 hour and stained using GelRed.
+
                    B
              </small>
+
                    showed a C<sub>t</sub> of 11, sample A contained 2<sup>3</sup>&nbsp;= 8 times more template.)
              <br />
+
                </p>
              <br />
+
                <br/>
 +
                <p>
 +
                    After running a DNA gel, we noticed that the obtained amplification products did not show the
 +
                    expected
 +
                    length. This may have been a result of distinct secondary structures of the tRNA species: the
 +
                    reverse
 +
                    transcription reaction was performed at 42 &deg;C which is the enzyme&rsquo;s optimum working
 +
                    temperature.
 +
                    However, this temperature is not high enough to prevent secondary structures or to break them up.
 +
                    Therefore,
 +
                    areas with secondary structures may have been inaccessible for the reverse transcriptase resulting
 +
                    in
 +
                    shorter cDNA fragments.
 +
                </p>
 +
                <br/>
 +
                <p>
 +
                    For this reason, we tested a second option to amplify single tRNA species specifically. A modified
 +
                    polymerase together with the specific reverse primer can be used to amplify the desired tRNA species
 +
                    using
 +
                    RNA as a template. This modified polymerase works at temperatures around 65 &deg;C and can use both
 +
                    RNA and
 +
                    DNA as a template. The reverse transcription reaction is thus not needed as a consecutive step
 +
                    anymore.
 +
                    Moreover, the modified enzyme creates the specific cDNA from RNA directly and the high temperature
 +
                    prevents
 +
                    secondary structures. The relative quantification based on C<sub>t </sub>values is the same as in
 +
                    the option
 +
                    described before.
 +
                </p>
 +
                <br/><br/>
 +
                <div class="notification">
 +
                    <h3 class="title is-5">References</h3>
 +
                    <ol>
 +
                        <li>
 +
                            I. A. Babarinde, Y. Li, A. P. Hutchins (2019) Computational Methods for Mapping, Assembly
 +
                            and
 +
                            Quantification for Coding and Non-coding Transcripts, Computational and Structural
 +
                            Biotechnology
 +
                            Journal, Vol. 17, pp 628-637
 +
                        </li>
 +
                    </ol>
 +
                    <p>&nbsp;</p>
 +
                    <ol start="2">
 +
                        <li>
 +
                            D. Jacob, K. Th&uuml;ring, A. Galliot, V. Marchand, A. Galvanin, A. Ciftci, K. Scharmann, M.
 +
                            Stock,
 +
                            J.‐Y. Roignant, S.A. Leidel, Y. Motorin, R. Schaffrath, R. Klassen, M. Helm (2019) Absolute
 +
                            Quantification of Noncoding RNA by Microscale Thermophoresis, Angewandte Chemie
 +
                            International Edition,
 +
                            Vol. 58, pp 9565 &ndash; 9569
 +
                        </li>
 +
                    </ol>
 +
                    <p>&nbsp;</p>
 +
                    <ol start="3">
 +
                        <li>
 +
                            T. S. Stenum, M. A. S&oslash;rensen, S. L. Svenningsen (2017) Quantification of the
 +
                            Abundance and
 +
                            Charging Levels of Transfer RNAs in&nbsp;<em>Escherichia coli</em>.&nbsp;Journal of Visual
 +
                            Experiments,
 +
                            Issue 126, e56212
 +
                        </li>
 +
                    </ol>
 +
                    <p>&nbsp;</p>
 +
                    <ol start="4">
 +
                        <li>
 +
                            Y. Guo, A. Bosompem, S.Mohan, B. Erdogan, F.Ye, K. C. Vickers, Q. Sheng, S. Zhao, C. Li,
 +
                            P.-F. Su, M.
 +
                            Jagasia, S. A. Strickland, E. A. Griffiths, A. S. Kim (2015) Transfer RNA detection by small
 +
                            RNA deep
 +
                            sequencing and disease association with myelodysplastic syndromes, BMC Genomics, 16:727
 +
                        </li>
 +
                    </ol>
 +
                    <p>&nbsp;</p>
 +
                    <ol start="5">
 +
                        <li>
 +
                            S. Honda, M. Shigematsu, K. Morichika, A. G. Telonis, Y. Kirino (2015) Four-leaf clover
 +
                            qRT-PCR: A
 +
                            convenient method for selective quantification of mature tRNA, RNA Biology, Vol. 12, pp 501
 +
                            &ndash; 508
 +
                        </li>
 +
                    </ol>
 +
                </div>
 +
            </div>
 +
            <div id="cloningtRNA" class="section-container">
 +
                <h2 class="title is-3">Cloning of tRNA fragments into pSB1C3</h2>
 +
                <div class="columns">
 +
                    <div class="column">
 +
                        <p>
 +
                            The tRNA fragments were synthesized by IDT and amplified by PCR according to the PCR
 +
                            protocol (<a
 +
                                href="https://2019.igem.org/wiki/images/f/f4/T--Stuttgart--Protocol_PCR.pdf"
 +
                        >Protocol_PCR.pdf</a
 +
                        >). The amplified tRNA fragments were validated via agarose gel electrophoresis (<a
 +
                                href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
 +
                        >Stuttgart--Protocol_Agarose_Gel.pdf</a
 +
                        >). Looking at Figure 1 all tRNA fragments showed a clear band at the desired height.
 +
                        </p>
 +
                        <img
 +
                                style="display: block; max-width: 500px; margin: 0 auto;"
 +
                                src="https://2019.igem.org/wiki/images/thumb/8/86/T--Stuttgart--Amplified_tRNA_fragments.png/592px-T--Stuttgart--Amplified_tRNA_fragments.png"
 +
                        />
 +
                        <small>
 +
                            Figure 1: Amplified tRNA fragments. The tRNA fragments AGA, CGC, TGC, TCC and AGG were
 +
                            amplified via
 +
                            PCR. The PCR products were separated by agarose gel electrophoresis. A 2% agarose gel was
 +
                            prepared and
 +
                            10 &micro;L were loaded for each probe ((1): AGA, (2): CGC, (3): TGC, (4): TCC, (5): AGG). 3
 +
                            &micro;L of
 +
                            Hyberladder 1 kb Bioline were loaded as a marker (M). The gel was run at 90 V for 1 hour and
 +
                            stained
 +
                            using MidoriGreen.
 +
                        </small>
 +
                        <br/>
 +
                        <br/>
 +
                        <p>
 +
                            In a first step, the tRNA fragments were cloned into the pSB1C3 vector. The pSB1C3 and the
 +
                            tRNA
 +
                            fragments AGA, AGG, CGG, TGC, TCC and a combined tRNA fragment containing all 5 tRNAs were
 +
                            digested
 +
                            using the restriction enzymes XbaI and SpeI. <br/>
 +
                            After purification, (<a
 +
                                href="https://2019.igem.org/wiki/images/3/3f/T--Stuttgart--Protocol_Clean_and_Concentrate.pdf"
 +
                        >
 +
                            Protocol_Clean_and_Concentrate.pdf</a
 +
                        >) the digested fragments were ligated using the T4 DNA ligase (see
 +
                            <a href="https://2019.igem.org/wiki/images/0/03/T--Stuttgart--Protocol_BioBrick_Cloning.pdf">
 +
                                Protocol_BioBrick_Cloning.pdf</a
 +
                            >). The ligated DNA fragments were transformed into DH5&alpha; (<a
 +
                                href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf"
 +
                        >
 +
                            Protocol_Transformation.pdf</a
 +
                        >). The plasmid obtained from the colonies (<a
 +
                                href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
 +
                        >
 +
                            Protocol_Plasmid_Preparation.pdf</a
 +
                        >) was digested with XbaI to gain linear Plasmid and separated by agarose gel electrophoresis
 +
                            (<a
 +
                                href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
 +
                        >
 +
                            Protocol_Agarose_Gel.pdf</a
 +
                        >). Looking at Figure 2 the obtained plasmids showed no insert, only pSB1C3. Also visible is,
 +
                            that
 +
                            despite the digestion, circular, supercoiled and open circular structures of the plasmid are
 +
                            still
 +
                            present. This indicates inefficient digestion by the restriction enzymes.
 +
                        </p>
 +
                        <br/>
 +
                        <img
 +
                                style="display: block; max-width: 500px; margin: 0 auto;"
 +
                                src="https://2019.igem.org/wiki/images/thumb/8/8f/T--Stuttgart--Cloning_of_tRNA_fragments_into_pSB1C3.png/722px-T--Stuttgart--Cloning_of_tRNA_fragments_into_pSB1C3.png"
 +
                        />
 +
                        <small>
 +
                            Figure 2 - Cloning of tRNA fragments into pSB1C3. The pSB1C3 and the tRNA fragments were
 +
                            digested using
 +
                            the restriction enzymes XbaI and SpeI. After purification, the digested fragments were
 +
                            ligated using the
 +
                            T4 DNA ligase. The ligated DNA fragments were transformed into DH5&alpha; and subsequently
 +
                            prepared. The
 +
                            obtained plasmids were digested with XbaI before the agarose gel electrophoresis. A 1%
 +
                            agarose gel was
 +
                            prepared and 10 &micro;L were loaded for each probe ((1): AGA, (2): AGG, (3): CGG, (4): TGC,
 +
                            (5): TCC,
 +
                            (6): Combined tRNA fragment). As a control (C) the linear pSB1C3 was loaded. 3 &micro;L of
 +
                            GeneRuler,
 +
                            1kb Plus DNA Ladder was loaded as a marker (M). The gel was run at 90 V for 1 hour and
 +
                            stained using
 +
                            GelRed.
 +
                        </small>
 +
                        <br/>
 +
                        <br/>
  
              <p>
+
                        <p>
                Since the cloning showed inefficient digestion by the enzymes
+
                            Since the cloning showed inefficient digestion by the enzymes XbaI and SpeI, it was
                XbaI and SpeI, it was performed again with the enzymes EcoRI-HF
+
                            performed again with
                and PstI. The pSB1C3 and the tRNA fragments AGA, AGG, CGG, TGC,
+
                            the enzymes EcoRI-HF and PstI. The pSB1C3 and the tRNA fragments AGA, AGG, CGG, TGC, TCC and
                TCC and a combined tRNA fragment were digested using the
+
                            a combined
                restriction enzymes EcoRI-HF and PstI.<br />
+
                            tRNA fragment were digested using the restriction enzymes EcoRI-HF and PstI.<br/>
                After purification, (<a
+
                            After purification, (<a
                  href="https://2019.igem.org/wiki/images/3/3f/T--Stuttgart--Protocol_Clean_and_Concentrate.pdf"
+
                                href="https://2019.igem.org/wiki/images/3/3f/T--Stuttgart--Protocol_Clean_and_Concentrate.pdf"
                >
+
                        >
                  Protocol_Clean_and_Concentrate.pdf</a
+
                            Protocol_Clean_and_Concentrate.pdf</a
                >) the digested fragments were ligated using the T4 DNA ligase
+
                        >) the digested fragments were ligated using the T4 DNA ligase (see
                (see
+
                            <a href="https://2019.igem.org/wiki/images/0/03/T--Stuttgart--Protocol_BioBrick_Cloning.pdf">
                <a
+
                                Protocol_BioBrick_Cloning.pdf</a
                  href="https://2019.igem.org/wiki/images/0/03/T--Stuttgart--Protocol_BioBrick_Cloning.pdf"
+
                            >). The ligated DNA fragments were transformed into DH5&alpha; cells (<a
                >
+
                                href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf"
                  Protocol_BioBrick_Cloning.pdf</a
+
                        >
                >). The ligated DNA fragments were transformed into DH5&alpha;
+
                            Protocol_Transformation.pdf</a
                cells (<a
+
                        >). The plasmid obtained from the colonies (<a
                  href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf"
+
                                href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
                >
+
                        >
                  Protocol_Transformation.pdf</a
+
                            Protocol_Plasmid_Preparation.pdf</a
                >). The plasmid obtained from the colonies (<a
+
                        >) was digested with EcoRI-HF to gain linear Plasmid and separated by agarose gel
                  href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
+
                            electrophoresis (<a
                >
+
                                href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
                  Protocol_Plasmid_Preparation.pdf</a
+
                        >Protocol_Agarose_Gel.pdf</a
                >) was digested with EcoRI-HF to gain linear Plasmid and
+
                        >). The agarose gel revealed no successful cloning as all obtained plasmids showed no insert,
                separated by agarose gel electrophoresis (<a
+
                            only
                  href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
+
                            pSB1C3 (data not shown).
                  >Protocol_Agarose_Gel.pdf</a
+
                        </p>
                >). The agarose gel revealed no successful cloning as all
+
                        <br/>
                obtained plasmids showed no insert, only pSB1C3 (data not
+
                    </div>
                shown).
+
                    <div class="column">
              </p>
+
                        <h2 class="title is-4">
              <br />
+
                            Cloning of tRNA fragments into ptRNA_backbone via BioBrick Cloning
              <h2 class="title is-4">
+
                        </h2>
                Cloning of tRNA fragments into ptRNA_backbone via BioBrick
+
 
                Cloning
+
                        <p>
              </h2>
+
                            In a first step, the self-designed linear ptRNA_backbone from IDT was ligated according to
 +
                            the NEB
 +
                            Ligation Protocol with T4 DNA Ligase (see
 +
                            <a href="https://2019.igem.org/wiki/images/2/2e/T--Stuttgart--Blunt_End_Ligation.pdf">
 +
                                T--Stuttgart--Blunt_End_Ligation.pdf</a
 +
                            >). Afterward, the ligated ptRNA-backbone was transformed in <em>E. coli</em> DH5a cells
 +
                            (see
 +
                            <a href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf">
 +
                                Protocol_Transformation.pdf</a
 +
                            >). Successfully transformed DH5&alpha; cells were selected on LB agar plates containing
 +
                            tetracycline.
 +
                            The next day the circular ptRNA_backbone was prepared from the colonies according to the
 +
                            Plasmid
 +
                            Preparation protocol (<a
 +
                                href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
 +
                        >
 +
                            Protocol_Plasmid_Preparation.pdf</a
 +
                        >). The plasmid obtained from the colonies was digested with EcoRI-HF to gain linear Plasmid and
 +
                            separated by agarose gel electrophoresis (<a
 +
                                href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
 +
                        >
 +
                            Protocol_Agarose_Gel.pdf</a
 +
                        >). Looking at Figure 3 all plasmids run at the desired length which corresponds to the length
 +
                            of the
 +
                            ptRNA_backbone 2159 bp.
 +
                        </p>
 +
                        <br/>
 +
                        <br/>
 +
                        <img
 +
                                style="display: block; max-width: 500px; margin: 0 auto;"
 +
                                src="https://2019.igem.org/wiki/images/thumb/9/9f/T--Stuttgart--Cloning_of_ptRNA_backbone.png/510px-T--Stuttgart--Cloning_of_ptRNA_backbone.png"
 +
                        />
 +
                        <small style="text-align: justify">
 +
                            Figure 3 -Cloning of ptRNA_backbone. The linear ptRNA_backbone fragment from IDT was ligated
 +
                            using the
 +
                            T4 DNA Ligase. The ligated ptRNA-backbone was transformed into DH5&alpha; and subsequently
 +
                            prepared. The
 +
                            obtained plasmids were digested with EcoRI-HF before the agarose gel electrophoresis. A 1%
 +
                            agarose gel
 +
                            was prepared and 10 &micro;L were loaded for each probe ((1): ptRNA_backbone gBlock from
 +
                            IDT, (2):
 +
                            colony 2, (3): colony 3, (4): colony 4, (5): colony 5, (6): colony 6). 3 &micro;L of
 +
                            GeneRuler, 1kb Plus
 +
                            DNA Ladder was loaded as a marker (M). The gel was run at 90 V for 1 hour and stained using
 +
                            GelRed.
 +
                        </small>
 +
                        <br/>
 +
                        <br/>
 +
                        <p>
 +
                            The ptRNA_backbone and the previously amplified tRNA fragments AGA, AGG, CGG, TGC, TCC and a
 +
                            combined
 +
                            tRNA fragment were digested using the restriction enzymes EcoRI-HF and PstI. After
 +
                            purification, (<a
 +
                                href="https://2019.igem.org/wiki/images/3/3f/T--Stuttgart--Protocol_Clean_and_Concentrate.pdf"
 +
                        >
 +
                            Protocol_Clean_and_Concentrate.pdf</a
 +
                        >) the digested fragments were ligated using the T4 DNA ligase (see
 +
                            <a href="https://2019.igem.org/wiki/images/0/03/T--Stuttgart--Protocol_BioBrick_Cloning.pdf">
 +
                                Protocol_BioBrick_Cloning.pdf</a
 +
                            >). The ligated DNA fragments were transformed into DH5&alpha; (<a
 +
                                href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf"
 +
                        >
 +
                            Protocol_Transformation.pdf</a
 +
                        >). The plasmid obtained from the colonies (<a
 +
                                href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
 +
                        >
 +
                            Protocol_Plasmid_Preparation.pdf</a
 +
                        >) was digested with EcoRI-HF to gain linear Plasmid and separated by agarose gel
 +
                            electrophoresis (<a
 +
                                href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
 +
                        >
 +
                            Protocol_Agarose_Gel.pdf</a
 +
                        >). Figure 4 reveals no successful cloning as all obtained Plasmids show no insert, only
 +
                            ptRNA_backbone.
 +
                        </p>
 +
 
 +
                        <img
 +
                                style="display: block; max-width: 500px; margin: 0 auto;"
 +
                                src="https://2019.igem.org/wiki/images/thumb/6/6a/T--Stuttgart--Cloning_of_tRNA_fragments_into_ptRNA_backbone.png/576px-T--Stuttgart--Cloning_of_tRNA_fragments_into_ptRNA_backbone.png"
 +
                        />
 +
                        <small>
 +
                            Figure 4 - Cloning of tRNA fragments into ptRNA_backbone. The ptRNA_backbone and the tRNA
 +
                            fragments were
 +
                            digested using the restriction enzymes EcoRI-HF and PstI. After purification, the digested
 +
                            fragments
 +
                            were ligated using the T4 DNA ligase. The ligated DNA fragments were transformed into DH5&alpha;
 +
                            and
 +
                            subsequently prepared. The obtained plasmids were digested with EcoRI-HF before the agarose
 +
                            gel
 +
                            electrophoresis. A 1% agarose gel was prepared and 10 &micro;L were loaded for each probe
 +
                            ((1): AGA,
 +
                            (2): AGG, (3): CGG, (4): TGC, (5): TCC, (6): Combined tRNA fragment). As a control (C) the
 +
                            linear
 +
                            ptRNA_backbone was loaded. 3 &micro;L of GeneRuler, 1kb Plus DNA Ladder was loaded as a
 +
                            marker (M). The
 +
                            gel was run at 90 V for 1 hour and stained using GelRed.
 +
                        </small>
 +
                        <br/>
 +
                        <p>
 +
                            This BioBrick cloning was repeated several times using different EcoRI-HF and PstI stocks.
 +
                            Following
 +
                            transformation in DH5&alpha; revealed no successful cloning. The colonies obtained showed no
 +
                            insert in
 +
                            an agarose gel and only ptRNA_backbone. Following transformation in competent Vibrio
 +
                            natriegens cells
 +
                            also revealed no successful cloning (data not shown).
 +
                        </p>
 +
                        <br/>
 +
                        <br/>
 +
                        <h2 class="title is-4">
 +
                            Cloning of tRNA fragments into ptRNA_backbone via Gibson Assembly
 +
                        </h2>
 +
 
 +
                        <p>
 +
                            Cloning of tRNA fragments into ptRNA_backbone was also performed using Gibson Assembly.
 +
                            Gibson Assembly
 +
                            was conducted according to the protocol Gibson Assembly (<a
 +
                                href="https://2019.igem.org/wiki/images/6/6c/T--Stuttgart--Protocol_Gibson_Assembly.pdf"
 +
                        >
 +
                            Protocol_Gibson_Assembly.pdf</a
 +
                        >). The Gibson reaction was transformed into competent DH5&alpha; cells (<a
 +
                                href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf"
 +
                        >
 +
                            Protocol_Transformation.pdf</a
 +
                        >). The plasmid obtained from the colonies (<a
 +
                                href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
 +
                        >
 +
                            Protocol_Plasmid_Preparation.pdf</a
 +
                        >) was digested with EcoRI-HF to gain linear Plasmid and separated by agarose gel
 +
                            electrophoresis (<a
 +
                                href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
 +
                        >
 +
                            Protocol_Agarose_Gel.pdf</a
 +
                        >). Figure 5 reveals no successful cloning as all obtained Plasmids show no insert, only
 +
                            ptRNA_backbone.
 +
                        </p>
 +
                        <img
 +
                                style="display: block; max-width: 500px; margin: 0 auto;"
 +
                                src="https://2019.igem.org/wiki/images/thumb/8/82/T--Stuttgart--Gibson_Assembly_of_tRNA_fragments_into_ptRNA_backbone.png/527px-T--Stuttgart--Gibson_Assembly_of_tRNA_fragments_into_ptRNA_backbone.png"
 +
                        />
 +
                        <small
 +
                        >Figure 5 -Gibson Assembly of tRNA fragments into ptRNA_backbone. Gibson Assembly was performed
 +
                            according to the Gibson Assembly Protocol. The Gibson Assembly reaction was transformed into
 +
                            DH5&alpha;
 +
                            and subsequently prepared. The obtained plasmids were digested with EcoRI-HF before the
 +
                            agarose gel
 +
                            electrophoresis. A 1% agarose gel was prepared and 10 &micro;L were loaded for each probe
 +
                            ((1): AGA,
 +
                            (2): AGG, (3): CGG, (4): TGC, (5): TCC). As a control (C) the linear ptRNA_backbone was
 +
                            loaded. 3
 +
                            &micro;L of GeneRuler, 1kb Plus DNA Ladder was loaded as a marker (M). The gel was run at 90
 +
                            V for 1
 +
                            hour and stained using GelRed.</small
 +
                        >
 +
                        <br/>
 +
                        <br/>
 +
                        <p>
 +
                            Cloning of tRNA fragments into ptRNA_backbone via Gibson Assembly was repeated with another
 +
                            Gibson
 +
                            Assembly Master Mix and revealed no successful cloning. The colonies obtained showed no
 +
                            insert in an
 +
                            agarose gel and only ptRNA_backbone (data not shown).
 +
                        </p>
 +
                        <br/>
 +
                        <br/>
 +
                        <h2 class="title is-4">
 +
                            Isolation of <em>Vibrio natriegens</em> DSM 759 genome chr.1 and amplification of tRNAs
 +
                        </h2>
 +
                        <p>
 +
                            As an alternative to cloning of tRNA fragments provided by IDT, the tRNAs AGA, AGG, CGG, TGC
 +
                            and TCC
 +
                            were amplified from the
 +
                            <em>Vibrio natriegens</em> DSM 759 genome. Therefore, the <em>Vibrio natriegens</em> DSM 759
 +
                            genome
 +
                            chr.1 was isolated according to the gDNA Extraction protocol (<a
 +
                                href="https://2019.igem.org/wiki/images/c/c0/T--Stuttgart--gDNA_extraction.pdf"
 +
                        >
 +
                            gDNA_extraction.pdf</a
 +
                        >). The tRNA fragments AGA, AGG, CGG, TGC, TCC were amplified from the <em>Vibrio
 +
                            natriegens</em> DSM
 +
                            759 genome via PCR with appropriate primers (see
 +
                            <a href="https://2019.igem.org/wiki/images/f/f4/T--Stuttgart--Protocol_PCR.pdf">
 +
                                Protocol_PCR.pdf</a>).
 +
                            Looking at Figure 6 all tRNA fragments showed a clear band at the desired height. The tRNA
 +
                            fragments
 +
                            were extracted from the agarose gel according to the gel extraction protocol (<a
 +
                                href="https://2019.igem.org/wiki/images/3/32/T--Stuttgart--Protocol_Gel_Extraction.pdf"
 +
                        >
 +
                            Protocol_Gel_Extraction.pdf</a
 +
                        >).
 +
                        </p>
 +
                        <br/>
 +
                        <br/>
 +
                        <img
 +
                                style="display: block; max-width: 500px; margin: 0 auto;"
 +
                                src="https://2019.igem.org/wiki/images/thumb/3/31/T--Stuttgart--Amplification_of_tRNAs_from_Vibrio_natriegens_genome.png/800px-T--Stuttgart--Amplification_of_tRNAs_from_Vibrio_natriegens_genome.png"
 +
                        />
 +
                        <small
 +
                        >Figure 6: Amplification of tRNAs from the Vibrio natriegens DSM 759 genome. The Vibrio
 +
                            natriegens DSM
 +
                            759 genome chr.1 was isolated according to the Protocol gDNA Extraction. The tRNA fragments
 +
                            AGA, AGG,
 +
                            CGG, TGC, TCC were amplified from the Vibrio natriegens DSM 759 genome via PCR with
 +
                            appropriate primers.
 +
                            A 1.5 % agarose gel was prepared and 10 &micro;L were loaded for each probe ((1): AGA, (2):
 +
                            AGG, (3):
 +
                            CGG, (4): TGC, (5): TCC). 3 &micro;L of GeneRuler, 1kb Plus DNA Ladder was loaded as a
 +
                            marker (M). The
 +
                            gel was run at 90 V for 1 hour and stained using GelRed.</small
 +
                        >
 +
                        <br/>
 +
                    </div>
 +
                </div>
  
              <p>
+
                <p>
                 In a first step, the self-designed linear ptRNA_backbone from
+
                    <strong
                IDT was ligated according to the NEB Ligation Protocol with T4
+
                    >Cloning of tRNA fragments (amplified from <em>Vibrio natriegens</em> DSM 759 genome) into
                DNA Ligase (see
+
                        ptRNA_backbone
                <a
+
                        via BioBrick Cloning</strong
                  href="https://2019.igem.org/wiki/images/2/2e/T--Stuttgart--Blunt_End_Ligation.pdf"
+
                    >
 +
                 </p>
 +
                <p>
 +
                    The ptRNA_backbone and the previously amplified tRNA fragments AGA, AGG, CGG, TGC, TCC from the
 +
                    <em>Vibrio natriegens</em> DSM 759 genome were digested using the restriction enzymes EcoRI-HF and
 +
                    PstI.
 +
                    After purification, (<a
 +
                        href="https://2019.igem.org/wiki/images/3/3f/T--Stuttgart--Protocol_Clean_and_Concentrate.pdf"
 
                 >
 
                 >
                  T--Stuttgart--Blunt_End_Ligation.pdf</a
+
                    Protocol_Clean_and_Concentrate.pdf</a
                 >). Afterward, the ligated ptRNA-backbone was transformed in
+
                 >) the digested fragments were ligated using the T4 DNA ligase (see
                <em>E. coli</em> DH5a cells (see
+
                    <a href="https://2019.igem.org/wiki/images/0/03/T--Stuttgart--Protocol_BioBrick_Cloning.pdf">
                <a
+
                        Protocol_BioBrick_Cloning.pdf</a
                  href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf"
+
                    >). The ligated DNA fragments were transformed into competent DH5&alpha; cells (<a
 +
                        href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf"
 
                 >
 
                 >
                  Protocol_Transformation.pdf</a
+
                    Protocol_Transformation.pdf</a
                >). Successfully transformed DH5&alpha; cells were selected on
+
                LB agar plates containing tetracycline. The next day the
+
                circular ptRNA_backbone was prepared from the colonies according
+
                to the Plasmid Preparation protocol (<a
+
                  href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
+
                >
+
                  Protocol_Plasmid_Preparation.pdf</a
+
                >). The plasmid obtained from the colonies was digested with
+
                EcoRI-HF to gain linear Plasmid and separated by agarose gel
+
                electrophoresis (<a
+
                  href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
+
                >
+
                  Protocol_Agarose_Gel.pdf</a
+
                >). Looking at Figure 3 all plasmids run at the desired length
+
                which corresponds to the length of the ptRNA_backbone 2159 bp.
+
              </p>
+
              <br />
+
              <br />
+
              <img
+
                style="display: block; max-width: 500px; margin: 0 auto;"
+
                src="https://2019.igem.org/wiki/images/thumb/9/9f/T--Stuttgart--Cloning_of_ptRNA_backbone.png/510px-T--Stuttgart--Cloning_of_ptRNA_backbone.png"
+
              />
+
              <small style="text-align: justify">
+
                Figure 3 -Cloning of ptRNA_backbone. The linear ptRNA_backbone
+
                fragment from IDT was ligated using the T4 DNA Ligase. The
+
                ligated ptRNA-backbone was transformed into DH5&alpha; and
+
                subsequently prepared. The obtained plasmids were digested with
+
                EcoRI-HF before the agarose gel electrophoresis. A 1% agarose
+
                gel was prepared and 10 &micro;L were loaded for each probe
+
                ((1): ptRNA_backbone gBlock from IDT, (2): colony 2, (3): colony
+
                3, (4): colony 4, (5): colony 5, (6): colony 6). 3 &micro;L of
+
                GeneRuler, 1kb Plus DNA Ladder was loaded as a marker (M). The
+
                gel was run at 90 V for 1 hour and stained using GelRed.
+
              </small>
+
              <br />
+
              <br />
+
              <p>
+
                The ptRNA_backbone and the previously amplified tRNA fragments
+
                AGA, AGG, CGG, TGC, TCC and a combined tRNA fragment were
+
                digested using the restriction enzymes EcoRI-HF and PstI. After
+
                purification, (<a
+
                  href="https://2019.igem.org/wiki/images/3/3f/T--Stuttgart--Protocol_Clean_and_Concentrate.pdf"
+
                >
+
                  Protocol_Clean_and_Concentrate.pdf</a
+
                >) the digested fragments were ligated using the T4 DNA ligase
+
                (see
+
                <a
+
                  href="https://2019.igem.org/wiki/images/0/03/T--Stuttgart--Protocol_BioBrick_Cloning.pdf"
+
                >
+
                  Protocol_BioBrick_Cloning.pdf</a
+
                >). The ligated DNA fragments were transformed into DH5&alpha;
+
                (<a
+
                  href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf"
+
                >
+
                  Protocol_Transformation.pdf</a
+
 
                 >). The plasmid obtained from the colonies (<a
 
                 >). The plasmid obtained from the colonies (<a
                  href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
+
                        href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
 
                 >
 
                 >
                  Protocol_Plasmid_Preparation.pdf</a
+
                    Protocol_Plasmid_Preparation.pdf</a
                 >) was digested with EcoRI-HF to gain linear Plasmid and
+
                 >) was digested with EcoRI-HF and PstI to release inserted tRNA fragments from the ptRNA_backbone and
                separated by agarose gel electrophoresis (<a
+
                    gain
                  href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
+
                    linear plasmid. The DNA fragments were separated by agarose gel electrophoresis (<a
 +
                        href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
 
                 >
 
                 >
                  Protocol_Agarose_Gel.pdf</a
+
                    Protocol_Agarose_Gel.pdf</a
                 >). Figure 4 reveals no successful cloning as all obtained
+
                 >). Looking at Figure 7 no insert band was visible for the obtained plasmids, only ptRNA_backbone,
                 Plasmids show no insert, only ptRNA_backbone.
+
                    suggesting no successful cloning.
              </p>
+
                </p>
 +
                <img
 +
                        style="display: block; max-width: 500px; margin: 0 auto;"
 +
                        src="https://2019.igem.org/wiki/images/thumb/5/5e/T--Stuttgart--Biobrick_cloning_of_tRNA_fragments_into_ptRNA_backbone.png/521px-T--Stuttgart--Biobrick_cloning_of_tRNA_fragments_into_ptRNA_backbone.png"
 +
                />
 +
                <small>
 +
                    Figure 7: BioBrick cloning of tRNA fragments into ptRNA_backbone. The tRNA fragments were previously
 +
                    amplified from the Vibrio natriegens DSM 759 genome. The ptRNA_backbone and the tRNA fragments were
 +
                    digested
 +
                    using the restriction enzymes EcoRI-HF and PstI. After purification, the digested fragments were
 +
                    ligated
 +
                    using the T4 DNA ligase. The ligated DNA fragments were transformed into DH5&alpha; and subsequently
 +
                    prepared. The obtained plasmids were digested with EcoRI-HF and PstI before the agarose gel
 +
                    electrophoresis.
 +
                    A 1% agarose gel was prepared and 10 &micro;L were loaded for each probe ((1): AGA, (2): AGG, (3):
 +
                    CGG, (4):
 +
                    TGC, (5): ACC). As a control (C) the linear ptRNA_backbone was loaded. 3 &micro;L of GeneRuler, 1kb
 +
                    Plus DNA
 +
                    Ladder was loaded as a marker (M). The gel was run at 90 V for 1 hour and stained using GelRed.
 +
                 </small>
 +
                <p>
 +
                    Following transformation in competent Vibrio natriegens cells also revealed no successful cloning
 +
                    (data not
 +
                    shown).
 +
                </p>
 +
                <br/>
 +
                <br/>
 +
                <h3 class="title is-4">
 +
                    Cloning of tRNA fragments (amplified from
 +
                    <em>Vibrio natriegens</em> DSM 759 genome) into ptRNA_backbone via NEBuilder HiFi DNA Assembly
 +
                </h3>
 +
                <p>
 +
                    The tRNA fragments were previously amplified from
 +
                    <em>Vibrio natriegens</em> DSM 759 genome. The NEBuilder HiFi DNA Assembly was performed according
 +
                    to the
 +
                    Protocol NEBuilder HiFi DNA Assembly (<a
 +
                        href="https://2019.igem.org/wiki/images/2/25/T--Stuttgart--Protocols_NEBuilder_HiFi_DNA_Assembly.pdf"
 +
                >https://2019.igem.org/wiki/images/2/25/T--Stuttgart--Protocols_NEBuilder_HiFi_DNA_Assembly.pdf</a
 +
                >). Following transformation into competent DH5&alpha; cells revealed no successful cloning as no
 +
                    colonies
 +
                    were obtained. Following transformation in competent <em>Vibrio natriegens</em> cells also revealed
 +
                    no
 +
                    successful cloning (data not shown).
 +
                </p>
  
              <img
+
                 <br/>
                 style="display: block; max-width: 500px; margin: 0 auto;"
+
                 <br/>
                src="https://2019.igem.org/wiki/images/thumb/6/6a/T--Stuttgart--Cloning_of_tRNA_fragments_into_ptRNA_backbone.png/576px-T--Stuttgart--Cloning_of_tRNA_fragments_into_ptRNA_backbone.png"
+
                <h3 class="title is-4">
              />
+
                    Cloning of tRNA fragments (amplified from
              <small>
+
                    <em>Vibrio natriegens</em> DSM 759 genome) into ptRNA_backbone via Gibson Assembly
                Figure 4 - Cloning of tRNA fragments into ptRNA_backbone. The
+
                 </h3>
                ptRNA_backbone and the tRNA fragments were digested using the
+
                restriction enzymes EcoRI-HF and PstI. After purification, the
+
                digested fragments were ligated using the T4 DNA ligase. The
+
                ligated DNA fragments were transformed into DH5&alpha; and
+
                subsequently prepared. The obtained plasmids were digested with
+
                EcoRI-HF before the agarose gel electrophoresis. A 1% agarose
+
                gel was prepared and 10 &micro;L were loaded for each probe
+
                ((1): AGA, (2): AGG, (3): CGG, (4): TGC, (5): TCC, (6): Combined
+
                tRNA fragment). As a control (C) the linear ptRNA_backbone was
+
                loaded. 3 &micro;L of GeneRuler, 1kb Plus DNA Ladder was loaded
+
                as a marker (M). The gel was run at 90 V for 1 hour and stained
+
                using GelRed.
+
              </small>
+
              <br />
+
              <p>
+
                 This BioBrick cloning was repeated several times using different
+
                EcoRI-HF and PstI stocks. Following transformation in DH5&alpha;
+
                revealed no successful cloning. The colonies obtained showed no
+
                insert in an agarose gel and only ptRNA_backbone. Following
+
                transformation in competent Vibrio natriegens cells also
+
                revealed no successful cloning (data not shown).
+
              </p>
+
              <br />
+
              <br />
+
              <h2 class="title is-4">
+
                Cloning of tRNA fragments into ptRNA_backbone via Gibson
+
                 Assembly
+
              </h2>
+
  
              <p>
+
                <p>
                Cloning of tRNA fragments into ptRNA_backbone was also performed
+
                    Gibson Assembly was performed according to the protocol Gibson Assembly (<a
                using Gibson Assembly. Gibson Assembly was conducted according
+
                        href="https://2019.igem.org/wiki/images/6/6c/T--Stuttgart--Protocol_Gibson_Assembly.pdf"
                to the protocol Gibson Assembly (<a
+
                  href="https://2019.igem.org/wiki/images/6/6c/T--Stuttgart--Protocol_Gibson_Assembly.pdf"
+
                >
+
                  Protocol_Gibson_Assembly.pdf</a
+
                >). The Gibson reaction was transformed into competent
+
                DH5&alpha; cells (<a
+
                  href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf"
+
 
                 >
 
                 >
                  Protocol_Transformation.pdf</a
+
                    https://2019.igem.org/wiki/images/6/6c/T--Stuttgart--Protocol_Gibson_Assembly.pdf</a
 +
                >). Due to the orientation in the <em>Vibrio natriegens</em> DSM 759 genome only the tRNA fragments AGG
 +
                    and
 +
                    TGC could be used for Gibson Assembly. The Gibson reaction was transformed into competent DH5&alpha;
 +
                    cells
 +
                    (<a href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf">
 +
                    Protocol_Transformation.pdf</a
 
                 >). The plasmid obtained from the colonies (<a
 
                 >). The plasmid obtained from the colonies (<a
                  href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
+
                        href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
 
                 >
 
                 >
                  Protocol_Plasmid_Preparation.pdf</a
+
                    Protocol_Plasmid_Preparation.pdf</a
                 >) was digested with EcoRI-HF to gain linear Plasmid and
+
                 >) was digested with EcoRI-HF and PstI to release inserted tRNA fragments from the ptRNA_backbone and
                separated by agarose gel electrophoresis (<a
+
                    gain
                  href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
+
                    linear plasmid. The DNA fragments were separated by agarose gel electrophoresis (<a
 +
                        href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
 
                 >
 
                 >
                  Protocol_Agarose_Gel.pdf</a
+
                    Protocol_Agarose_Gel.pdf</a
                 >). Figure 5 reveals no successful cloning as all obtained
+
                 >). Looking at Figure 8 no insert band was visible for the obtained plasmids, only ptRNA_backbone,
                Plasmids show no insert, only ptRNA_backbone.
+
                    suggesting no successful cloning.
              </p>
+
                </p>
              <img
+
                <img
                style="display: block; max-width: 500px; margin: 0 auto;"
+
                        style="display: block; max-width: 500px; margin: 0 auto;"
                src="https://2019.igem.org/wiki/images/thumb/8/82/T--Stuttgart--Gibson_Assembly_of_tRNA_fragments_into_ptRNA_backbone.png/527px-T--Stuttgart--Gibson_Assembly_of_tRNA_fragments_into_ptRNA_backbone.png"
+
                        src="https://2019.igem.org/wiki/images/thumb/9/99/T--Stuttgart--Gibson_Assembly_of_tRNA_fragments_-2.png/512px-T--Stuttgart--Gibson_Assembly_of_tRNA_fragments_-2.png"
              />
+
                />
              <small
+
                <small>
                >Figure 5 -Gibson Assembly of tRNA fragments into
+
                    Figure 8: Gibson Assembly of tRNA fragments into ptRNA_backbone. Gibson Assembly was performed
                ptRNA_backbone. Gibson Assembly was performed according to the
+
                    according to
                Gibson Assembly Protocol. The Gibson Assembly reaction was
+
                    the Gibson Assembly Protocol. The tRNA fragments were previously amplified from the Vibrio
                transformed into DH5&alpha; and subsequently prepared. The
+
                    natriegens DSM
                obtained plasmids were digested with EcoRI-HF before the agarose
+
                    759 genome. The Gibson Assembly reaction was transformed into DH5&alpha; and subsequently prepared.
                gel electrophoresis. A 1% agarose gel was prepared and 10
+
                    The
                &micro;L were loaded for each probe ((1): AGA, (2): AGG, (3):
+
                    obtained plasmids were digested with EcoRI-HF and PstI before the agarose gel electrophoresis. A 1%
                CGG, (4): TGC, (5): TCC). As a control (C) the linear
+
                    agarose
                ptRNA_backbone was loaded. 3 &micro;L of GeneRuler, 1kb Plus DNA
+
                    gel was prepared and 10 &micro;L were loaded for each probe ((1): AGG colony 1, (2): AGG colony 2,
                Ladder was loaded as a marker (M). The gel was run at 90 V for 1
+
                    (3): TGC
                hour and stained using GelRed.</small
+
                    colony 1, (4): TGC colony 2). 3 &micro;L of GeneRuler, 1kb Plus DNA Ladder was loaded as a marker
              >
+
                    (M). The
              <br />
+
                    gel was run at 90 V for 1 hour and stained using GelRed.
              <br />
+
                </small>
              <p>
+
                <br/>
                Cloning of tRNA fragments into ptRNA_backbone via Gibson
+
                <p>
                Assembly was repeated with another Gibson Assembly Master Mix
+
                    Cloning of tRNA fragments into ptRNA_backbone via Gibson Assembly was repeated with another Gibson
                and revealed no successful cloning. The colonies obtained showed
+
                    Assembly
                no insert in an agarose gel and only ptRNA_backbone (data not
+
                    Master Mix and revealed no successful cloning. The colonies obtained showed no insert in an agarose
                shown).
+
                    gel and
              </p>
+
                    only ptRNA_backbone. Following transformation of the Gibson reaction in competent
              <br />
+
                    <em>Vibrio natriegens</em> cells also revealed no successful cloning (data not shown).
              <br />
+
                 </p>
              <h2 class="title is-4">
+
                Isolation of <em>Vibrio natriegens</em> DSM 759 genome chr.1 and
+
                amplification of tRNAs
+
              </h2>
+
              <p>
+
                As an alternative to cloning of tRNA fragments provided by IDT,
+
                the tRNAs AGA, AGG, CGG, TGC and TCC were amplified from the
+
                <em>Vibrio natriegens</em> DSM 759 genome. Therefore, the
+
                <em>Vibrio natriegens</em> DSM 759 genome chr.1 was isolated
+
                according to the gDNA Extraction protocol (<a
+
                  href="https://2019.igem.org/wiki/images/c/c0/T--Stuttgart--gDNA_extraction.pdf"
+
                >
+
                  gDNA_extraction.pdf</a
+
                >). The tRNA fragments AGA, AGG, CGG, TGC, TCC were amplified
+
                 from the <em>Vibrio natriegens</em> DSM 759 genome via PCR with
+
                appropriate primers (see
+
                <a
+
                  href="https://2019.igem.org/wiki/images/f/f4/T--Stuttgart--Protocol_PCR.pdf"
+
                >
+
                  Protocol_PCR.pdf</a
+
                >). Looking at Figure 6 all tRNA fragments showed a clear band
+
                at the desired height. The tRNA fragments were extracted from
+
                the agarose gel according to the gel extraction protocol (<a
+
                  href="https://2019.igem.org/wiki/images/3/32/T--Stuttgart--Protocol_Gel_Extraction.pdf"
+
                >
+
                  Protocol_Gel_Extraction.pdf</a
+
                >).
+
              </p>
+
              <br />
+
              <br />
+
              <img
+
                style="display: block; max-width: 500px; margin: 0 auto;"
+
                src="https://2019.igem.org/wiki/images/thumb/3/31/T--Stuttgart--Amplification_of_tRNAs_from_Vibrio_natriegens_genome.png/800px-T--Stuttgart--Amplification_of_tRNAs_from_Vibrio_natriegens_genome.png"
+
              />
+
              <small
+
                >Figure 6: Amplification of tRNAs from the Vibrio natriegens DSM
+
                759 genome. The Vibrio natriegens DSM 759 genome chr.1 was
+
                isolated according to the Protocol gDNA Extraction. The tRNA
+
                fragments AGA, AGG, CGG, TGC, TCC were amplified from the Vibrio
+
                natriegens DSM 759 genome via PCR with appropriate primers. A
+
                1.5 % agarose gel was prepared and 10 &micro;L were loaded for
+
                each probe ((1): AGA, (2): AGG, (3): CGG, (4): TGC, (5): TCC). 3
+
                &micro;L of GeneRuler, 1kb Plus DNA Ladder was loaded as a
+
                marker (M). The gel was run at 90 V for 1 hour and stained using
+
                GelRed.</small
+
              >
+
              <br />
+
 
             </div>
 
             </div>
          </div>
+
            <br/><br/>
  
          <p>
+
            <div id="algae-media-based" class="section-container">
            <strong
+
                <h2 class="title is-3">
              >Cloning of tRNA fragments (amplified from
+
                    Media based on algae: first tests determining important substrates
              <em>Vibrio natriegens</em> DSM 759 genome) into ptRNA_backbone via
+
                </h2>
              BioBrick Cloning</strong
+
                <h3 class="title is-4">Medium based on LB</h3>
            >
+
                <p>
          </p>
+
                    To first determine whether the extract of
          <p>
+
                    <em>chlorella vulgaris </em>was a substitute for yeast extract, LB medium and medium containing
            The ptRNA_backbone and the previously amplified tRNA fragments AGA,
+
                    <em>chlorella vulgaris</em> extract instead of yeast extract were produced.
            AGG, CGG, TGC, TCC from the <em>Vibrio natriegens</em> DSM 759
+
                </p>
            genome were digested using the restriction enzymes EcoRI-HF and
+
                <ol>
            PstI. After purification, (<a
+
                    <li>
              href="https://2019.igem.org/wiki/images/3/3f/T--Stuttgart--Protocol_Clean_and_Concentrate.pdf"
+
                        Media were produced (<a
            >
+
                            href="https://2019.igem.org/File:T--Stuttgart--Protocol_media_first_experiments.pdf"
              Protocol_Clean_and_Concentrate.pdf</a
+
                    >Protocol_media_first_experiments.pdf</a
            >) the digested fragments were ligated using the T4 DNA ligase (see
+
                    >).
            <a
+
                    </li>
              href="https://2019.igem.org/wiki/images/0/03/T--Stuttgart--Protocol_BioBrick_Cloning.pdf"
+
                    <li>
            >
+
                        Media were inoculated with <em>escherichia coli</em> or
              Protocol_BioBrick_Cloning.pdf</a
+
                        <em>vibrio natriegens.</em>
            >). The ligated DNA fragments were transformed into competent
+
                    </li>
            DH5&alpha; cells (<a
+
                    <li>
              href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf"
+
                        After the over night culture, the turbidity of the tubes was observed.
            >
+
                    </li>
              Protocol_Transformation.pdf</a
+
                </ol>
            >). The plasmid obtained from the colonies (<a
+
                <br/>
              href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
+
                <p>Result: Growth of both bacteria was observed in both media.</p>
            >
+
                <br/>
              Protocol_Plasmid_Preparation.pdf</a
+
                <h3 class="title is-4">Medium without tryptone</h3>
            >) was digested with EcoRI-HF and PstI to release inserted tRNA
+
                <p>
            fragments from the ptRNA_backbone and gain linear plasmid. The DNA
+
                    To determine whether <em>chlorella vulgaris</em> extract was able to substitute tryptone as a medium
            fragments were separated by agarose gel electrophoresis (<a
+
                    component, additionally, media containing different concentrations of NaCl
              href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
+
                    <em>chlorella vulgaris</em> extract and yeast extract were prepared.
            >
+
                </p>
              Protocol_Agarose_Gel.pdf</a
+
                <ol>
            >). Looking at Figure 7 no insert band was visible for the obtained
+
                    <li>
            plasmids, only ptRNA_backbone, suggesting no successful cloning.
+
                        Media were produced (<a
          </p>
+
                            href="https://2019.igem.org/File:T--Stuttgart--Protocol_media_first_experiments.pdf"
          <img
+
                    >Protocol_media_first_experiments.pdf</a
            style="display: block; max-width: 500px; margin: 0 auto;"
+
                    >).
            src="https://2019.igem.org/wiki/images/thumb/5/5e/T--Stuttgart--Biobrick_cloning_of_tRNA_fragments_into_ptRNA_backbone.png/521px-T--Stuttgart--Biobrick_cloning_of_tRNA_fragments_into_ptRNA_backbone.png"
+
                    </li>
          />
+
                    <li>Media were inoculated with <em>vibrio natriegens.</em></li>
          <small>
+
                    <li>
            Figure 7: BioBrick cloning of tRNA fragments into ptRNA_backbone.
+
                        After the overnight culture, the turbidity of the tubes was observed.
            The tRNA fragments were previously amplified from the Vibrio
+
                    </li>
            natriegens DSM 759 genome. The ptRNA_backbone and the tRNA fragments
+
                </ol>
            were digested using the restriction enzymes EcoRI-HF and PstI. After
+
                <p>Result: No growth was detectable in media without tryptone.</p>
            purification, the digested fragments were ligated using the T4 DNA
+
            </div>
            ligase. The ligated DNA fragments were transformed into DH5&alpha;
+
            <br/><br/>
            and subsequently prepared. The obtained plasmids were digested with
+
            <div id="autolysis" class="section-container">
            EcoRI-HF and PstI before the agarose gel electrophoresis. A 1%
+
                <h2 class="title is-3">
            agarose gel was prepared and 10 &micro;L were loaded for each probe
+
                    Autolysis in combination with bead-milling Results
            ((1): AGA, (2): AGG, (3): CGG, (4): TGC, (5): ACC). As a control (C)
+
                </h2>
            the linear ptRNA_backbone was loaded. 3 &micro;L of GeneRuler, 1kb
+
                <h3 class="title is-4">Free amino acid estimation with rFAN assay</h3>
            Plus DNA Ladder was loaded as a marker (M). The gel was run at 90 V
+
                <p>
            for 1 hour and stained using GelRed.
+
                    Samples from Experiment
          </small>
+
                    <a
          <p>
+
                            target="_blank"
            Following transformation in competent Vibrio natriegens cells also
+
                            href="https://2019.igem.org/wiki/images/e/ec/T--Stuttgart--Protocol_Cell_extraction_with_autolysis_combined_with_bead-milling.pdf"
            revealed no successful cloning (data not shown).
+
                    >Cell_extraction_with_autolysis_combined_with_bead-milling.pdf</a
          </p>
+
                    >
          <br />
+
                    were used for the analysis.
          <br />
+
                </p>
          <h3 class="title is-4">
+
                <br/>
            Cloning of tRNA fragments (amplified from
+
                <p>
            <em>Vibrio natriegens</em> DSM 759 genome) into ptRNA_backbone via
+
                    Yeast extract is mostly obtained by autolysis <sup>1</sup>. In autolysis cells digest their own cell
            NEBuilder HiFi DNA Assembly
+
                    compounds with their own enzymes <sup>2</sup>. The idea was to transfer this commonly used principal
          </h3>
+
                    on
          <p>
+
                    algae. Therefore, <em>C. vulgaris </em>and <em>C. sorokiniana </em>were heated to 50&nbsp;&deg;C in
            The tRNA fragments were previously amplified from
+
                    alkaline
            <em>Vibrio natriegens</em> DSM 759 genome. The NEBuilder HiFi DNA
+
                    or acidic environment for 41&nbsp;h. To further crack the cell wall, both algae were treated with
            Assembly was performed according to the Protocol NEBuilder HiFi DNA
+
                    bead-milling afterwards. To quantify the success of cell wall disruption free amino acids were
            Assembly (<a
+
                    measured with
              href="https://2019.igem.org/wiki/images/2/25/T--Stuttgart--Protocols_NEBuilder_HiFi_DNA_Assembly.pdf"
+
                    rFAN-assay.
              >https://2019.igem.org/wiki/images/2/25/T--Stuttgart--Protocols_NEBuilder_HiFi_DNA_Assembly.pdf</a
+
                </p>
            >). Following transformation into competent DH5&alpha; cells
+
                <br/>
            revealed no successful cloning as no colonies were obtained.
+
                <p>
            Following transformation in competent
+
                    The yield of free amino acids was set into relation with the amount of biomass used in the
            <em>Vibrio natriegens</em> cells also revealed no successful cloning
+
                    experiment
            (data not shown).
+
                    (figure 1).
          </p>
+
                </p>
  
          <br />
+
                <div class="has-text-centered" style="width: 75%; margin:0 auto;">
          <br />
+
                    <canvas id="autolysis-figure-1"></canvas>
          <h3 class="title is-4">
+
                </div>
            Cloning of tRNA fragments (amplified from
+
            <em>Vibrio natriegens</em> DSM 759 genome) into ptRNA_backbone via
+
            Gibson Assembly
+
          </h3>
+
  
          <p>
+
                <script>
            Gibson Assembly was performed according to the protocol Gibson
+
                    window.onload = function () {
            Assembly (<a
+
                        var autolysisfigure1 = document.getElementById('autolysis-figure-1').getContext('2d');
              href="https://2019.igem.org/wiki/images/6/6c/T--Stuttgart--Protocol_Gibson_Assembly.pdf"
+
                        window.myBar = new Chart(autolysisfigure1, {
            >
+
                            type: 'bar',
              https://2019.igem.org/wiki/images/6/6c/T--Stuttgart--Protocol_Gibson_Assembly.pdf</a
+
                            data: {
            >). Due to the orientation in the <em>Vibrio natriegens</em> DSM 759
+
                                labels: [
            genome only the tRNA fragments AGG and TGC could be used for Gibson
+
                                    'yeast pH3',
            Assembly. The Gibson reaction was transformed into competent
+
                                    'yeast pH12',
            DH5&alpha; cells (<a
+
                                    'C.vulgaris pH3',
              href="https://2019.igem.org/wiki/images/8/83/T--Stuttgart--Protocol_Transformation.pdf"
+
                                    'C.vulgaris pH12',
            >
+
                                    'C.sorokeniana pH3',
              Protocol_Transformation.pdf</a
+
                                    'C.sorokeniana pH12'
            >). The plasmid obtained from the colonies (<a
+
                                ],
              href="https://2019.igem.org/wiki/images/2/2c/T--Stuttgart--Protocol_Plasmid_Preparation.pdf"
+
                                datasets: [
            >
+
                                    {
              Protocol_Plasmid_Preparation.pdf</a
+
                                        backgroundColor: ['#3e95cd', '#3e95cd', '#3e95cd', '#3e95cd', '#3e95cd', '#3e95cd'],
            >) was digested with EcoRI-HF and PstI to release inserted tRNA
+
                                        label: 'Population (millions)',
            fragments from the ptRNA_backbone and gain linear plasmid. The DNA
+
                                        data: [3.132222386, 4.852523798, 0.021842627, 0.037566219, 0.043678259, 0.087077261]
            fragments were separated by agarose gel electrophoresis (<a
+
                                    }
              href="https://2019.igem.org/wiki/images/b/ba/T--Stuttgart--Protocol_Agarose_Gel.pdf"
+
                                ]
            >
+
                            },
              Protocol_Agarose_Gel.pdf</a
+
                            options: {
            >). Looking at Figure 8 no insert band was visible for the obtained
+
                                responsive: true,
            plasmids, only ptRNA_backbone, suggesting no successful cloning.
+
                                legend: {
          </p>
+
                                    position: 'top'
          <img
+
                                },
            style="display: block; max-width: 500px; margin: 0 auto;"
+
                                scales: {
            src="https://2019.igem.org/wiki/images/thumb/9/99/T--Stuttgart--Gibson_Assembly_of_tRNA_fragments_-2.png/512px-T--Stuttgart--Gibson_Assembly_of_tRNA_fragments_-2.png"
+
                                    yAxes: [
          />
+
                                        {
          <small>
+
                                            scaleLabel: {
            Figure 8: Gibson Assembly of tRNA fragments into ptRNA_backbone.
+
                                                display: true,
            Gibson Assembly was performed according to the Gibson Assembly
+
                                                labelString: 'percentage of free amio acids [%]'
            Protocol. The tRNA fragments were previously amplified from the
+
                                            }
            Vibrio natriegens DSM 759 genome. The Gibson Assembly reaction was
+
                                        }
            transformed into DH5&alpha; and subsequently prepared. The obtained
+
                                    ]
            plasmids were digested with EcoRI-HF and PstI before the agarose gel
+
                                }
            electrophoresis. A 1% agarose gel was prepared and 10 &micro;L were
+
                            }
            loaded for each probe ((1): AGG colony 1, (2): AGG colony 2, (3):
+
                        });
            TGC colony 1, (4): TGC colony 2). 3 &micro;L of GeneRuler, 1kb Plus
+
                    };
            DNA Ladder was loaded as a marker (M). The gel was run at 90 V for 1
+
                </script>
            hour and stained using GelRed.
+
          </small>
+
          <br />
+
          <p>
+
            Cloning of tRNA fragments into ptRNA_backbone via Gibson Assembly
+
            was repeated with another Gibson Assembly Master Mix and revealed no
+
            successful cloning. The colonies obtained showed no insert in an
+
            agarose gel and only ptRNA_backbone. Following transformation of the
+
            Gibson reaction in competent
+
            <em>Vibrio natriegens</em> cells also revealed no successful cloning
+
            (data not shown).
+
          </p>
+
        </div>
+
        <br /><br />
+
  
        <div id="algae-media-based" class="section-container">
+
                <small
          <h2 class="title is-3">
+
                >Figure 1 -Autolysis and subsequent bead-milling of algae C. vulgaris and C. sorokiniana. The percentage
            Media based on algae: first tests determining important substrates
+
                    of
          </h2>
+
                    free amino acids [%] relates to the biomass used in the experiment.</small
          <h3 class="title is-4">Medium based on LB</h3>
+
                >
          <p>
+
                <br/>
            To first determine whether the extract of
+
                <p>
            <em>chlorella vulgaris </em>was a substitute for yeast extract, LB
+
                    The highest amounts of free amino acids were reached with yeast at pH 12 with 4.85&nbsp;%. Both
            medium and medium containing <em>chlorella vulgaris</em> extract
+
                    algae showed
            instead of yeast extract were produced.
+
                    very low yield in free amino acids. The best results showed <em>C. sorokiniana</em> at pH&nbsp;12.
          </p>
+
                    It is
          <ol>
+
                    possible, that the amount of glass beads and the size of the glass beads were to little, which led
            <li>
+
                    to less
              Media were produced (<a
+
                    cell wall disruption. Therefore, amino acids would have been retained within the cells. This would
                href="https://2019.igem.org/File:T--Stuttgart--Protocol_media_first_experiments.pdf"
+
                    explain
                >Protocol_media_first_experiments.pdf</a
+
                    the little amounts of free amino acids achieved with this method. Also, <em>C. vulgaris </em>and
              >).
+
                    <em>C. sorokinia </em>have a cell wall, in contrast to yeast <sup>3</sup>>. Cell walls are harder to
            </li>
+
                    break,
            <li>
+
                    than a plasma membrane. This could explain the difference between the yeast samples and the algae
              Media were inoculated with <em>escherichia coli</em> or
+
                    samples.
              <em>vibrio natriegens.</em>
+
                    Due to the low yield in free amino acids, it was decided to investigate other methods for cell
            </li>
+
                    extraction of
            <li>
+
                    algae.
              After the over night culture, the turbidity of the tubes was
+
                </p>
              observed.
+
                <br/>
            </li>
+
                <br/>
          </ol>
+
                <h3 class="title is-4">
          <br />
+
                    Anthrone assay to Determine Soluble Carbohydrate Concentration
          <p>Result: Growth of both bacteria was observed in both media.</p>
+
                </h3>
          <br />
+
                <p>
          <h3 class="title is-4">Medium without tryptone</h3>
+
                    Similar to the rFAN assay the anthrone assay is a method to detect free monosaccharides in a liquid.
          <p>
+
                    Therefor samples from the experiment
            To determine whether <em>chlorella vulgaris</em> extract was able to
+
                    <a href="https://2019.igem.org/wiki/images/f/f3/T--Stuttgart--Experiments_AnthroneAssay.pdf"
            substitute tryptone as a medium component, additionally, media
+
                    >Experiments_AnthroneAssay.pdf</a
            containing different concentrations of NaCl
+
                    >
            <em>chlorella vulgaris</em> extract and yeast extract were prepared.
+
                    were analyzed. Hereby a calibration curve with known amounts of glucose is created (Figure 2, left
          </p>
+
                    side).
          <ol>
+
                    This calibration curve creates the possibility to calculate the sugar concentration of the samples
            <li>
+
                    (Figure
              Media were produced (<a
+
                    2, right side).
                href="https://2019.igem.org/File:T--Stuttgart--Protocol_media_first_experiments.pdf"
+
                </p>
                >Protocol_media_first_experiments.pdf</a
+
              >).
+
            </li>
+
            <li>Media were inoculated with <em>vibrio natriegens.</em></li>
+
            <li>
+
              After the overnight culture, the turbidity of the tubes was
+
              observed.
+
            </li>
+
          </ol>
+
          <p>Result: No growth was detectable in media without tryptone.</p>
+
        </div>
+
        <br /><br />
+
        <div id="autolysis" class="section-container">
+
          <h2 class="title is-3">
+
            Autolysis in combination with bead-milling Results
+
          </h2>
+
          <h3 class="title is-4">Free amino acid estimation with rFAN assay</h3>
+
          <p>
+
            Samples from Experiment
+
            <a
+
              target="_blank"
+
              href="https://2019.igem.org/wiki/images/e/ec/T--Stuttgart--Protocol_Cell_extraction_with_autolysis_combined_with_bead-milling.pdf"
+
              >Cell_extraction_with_autolysis_combined_with_bead-milling.pdf</a
+
            >
+
            were used for the analysis.
+
          </p>
+
          <br />
+
          <p>
+
            Yeast extract is mostly obtained by autolysis <sup>1</sup>. In
+
            autolysis cells digest their own cell compounds with their own
+
            enzymes <sup>2</sup>. The idea was to transfer this commonly used
+
            principal on algae. Therefore, <em>C. vulgaris </em>and
+
            <em>C. sorokiniana </em>were heated to 50&nbsp;&deg;C in alkaline or
+
            acidic environment for 41&nbsp;h. To further crack the cell wall,
+
            both algae were treated with bead-milling afterwards. To quantify
+
            the success of cell wall disruption free amino acids were measured
+
            with rFAN-assay.
+
          </p>
+
          <br />
+
          <p>
+
            The yield of free amino acids was set into relation with the amount
+
            of biomass used in the experiment (figure 1).
+
          </p>
+
  
          <div class="has-text-centered" style="width: 75%; margin:0 auto;">
+
                 <img
            <canvas id="autolysis-figure-1"></canvas>
+
                        style="display: block; margin:0 auto;"
          </div>
+
                        src="https://2019.igem.org/wiki/images/thumb/2/2f/T--Stuttgart--FigureAutolysis_in_combination_with_bead-milling_Results2.png/800px-T--Stuttgart--FigureAutolysis_in_combination_with_bead-milling_Results2.png"
 
+
                />
          <script>
+
                <small
            window.onload = function() {
+
                >Figure 2: Pictures of the anthrone calibration curve as well as the anthrone assay of samples. For the
              var autolysisfigure1 = document
+
                    calibration curve known amounts of glucose is dissolved in water and the optical density at 620 nm
                 .getElementById("autolysis-figure-1")
+
                    is
                .getContext("2d");
+
                    measured (left side). This can be used to determine the monosaccharide concentration of anthone
              window.myBar = new Chart(autolysisfigure1, {
+
                    treated
                type: "bar",
+
                    samples which previously underwent autolysis (pH3 or pH6) with or without subsequent bead-mill
                data: {
+
                    treatment
                  labels: [
+
                    (RKM) (right side).</small
                    "yeast pH3",
+
                 >
                    "yeast pH12",
+
                    "C.vulgaris pH3",
+
                    "C.vulgaris pH12",
+
                    "C.sorokeniana pH3",
+
                    "C.sorokeniana pH12"
+
                  ],
+
                  datasets: [
+
                    {
+
                      backgroundColor: [
+
                        "#3e95cd",
+
                        "#3e95cd",
+
                        "#3e95cd",
+
                        "#3e95cd",
+
                        "#3e95cd",
+
                        "#3e95cd"
+
                      ],
+
                      label: "Population (millions)",
+
                      data: [
+
                        3.132222386,
+
                        4.852523798,
+
                        0.021842627,
+
                        0.037566219,
+
                        0.043678259,
+
                        0.087077261
+
                      ]
+
                    }
+
                  ]
+
                },
+
                options: {
+
                  responsive: true,
+
                  legend: {
+
                    position: "top"
+
                  },
+
                  scales: {
+
                    yAxes: [
+
                      {
+
                        scaleLabel: {
+
                          display: true,
+
                          labelString: "percentage of free amio acids [%]"
+
                        }
+
                      }
+
                    ]
+
                  }
+
                }
+
              });
+
            };
+
          </script>
+
 
+
          <small
+
            >Figure 1 -Autolysis and subsequent bead-milling of algae C.
+
            vulgaris and C. sorokiniana. The percentage of free amino acids [%]
+
            relates to the biomass used in the experiment.</small
+
          >
+
          <br />
+
          <p>
+
            The highest amounts of free amino acids were reached with yeast at
+
            pH 12 with 4.85&nbsp;%. Both algae showed very low yield in free
+
            amino acids. The best results showed <em>C. sorokiniana</em> at
+
            pH&nbsp;12. It is possible, that the amount of glass beads and the
+
            size of the glass beads were to little, which led to less cell wall
+
            disruption. Therefore, amino acids would have been retained within
+
            the cells. This would explain the little amounts of free amino acids
+
            achieved with this method. Also, <em>C. vulgaris </em>and
+
            <em>C. sorokinia </em>have a cell wall, in contrast to yeast
+
            <sup>3</sup>>. Cell walls are harder to break, than a plasma
+
            membrane. This could explain the difference between the yeast
+
            samples and the algae samples. Due to the low yield in free amino
+
            acids, it was decided to investigate other methods for cell
+
            extraction of algae.
+
          </p>
+
          <br />
+
          <br />
+
          <h3 class="title is-4">
+
            Anthrone assay to Determine Soluble Carbohydrate Concentration
+
          </h3>
+
          <p>
+
            Similar to the rFAN assay the anthrone assay is a method to detect
+
            free monosaccharides in a liquid. Therefor samples from the
+
            experiment
+
            <a
+
              href="https://2019.igem.org/wiki/images/f/f3/T--Stuttgart--Experiments_AnthroneAssay.pdf"
+
              >Experiments_AnthroneAssay.pdf</a
+
            >
+
            were analyzed. Hereby a calibration curve with known amounts of
+
            glucose is created (Figure 2, left side). This calibration curve
+
            creates the possibility to calculate the sugar concentration of the
+
            samples (Figure 2, right side).
+
          </p>
+
 
+
          <img
+
            style="display: block; margin:0 auto;"
+
            src="https://2019.igem.org/wiki/images/thumb/2/2f/T--Stuttgart--FigureAutolysis_in_combination_with_bead-milling_Results2.png/800px-T--Stuttgart--FigureAutolysis_in_combination_with_bead-milling_Results2.png"
+
          />
+
          <small
+
            >Figure 2: Pictures of the anthrone calibration curve as well as the
+
            anthrone assay of samples. For the calibration curve known amounts
+
            of glucose is dissolved in water and the optical density at 620 nm
+
            is measured (left side). This can be used to determine the
+
            monosaccharide concentration of anthone treated samples which
+
            previously underwent autolysis (pH3 or pH6) with or without
+
            subsequent bead-mill treatment (RKM) (right side).</small
+
          >
+
 
+
          <br />
+
          <br />
+
          <p>
+
            One can tell from the coloring of the samples in figure 2, that the
+
            carbohydrate concentration should differ very slightly between the
+
            samples pH3, pH6, bead mill extraction +pH3 and bead mill extraction
+
            +pH6. Due to the cloudiness of the control sample, a background
+
            corrected optical density could not be determined. Therefore, the
+
            coloring scheme served as evaluation for successful carbohydrate
+
            determination.
+
          </p>
+
          <p>
+
            Hereby, bead-mill (RKM) with subsequent autolysis at pH3 was
+
            determined to be the method of choice.
+
          </p>
+
          <br /><br />
+
          <div class="notification">
+
            <h3 class="title is-5">References</h3>
+
            <ol>
+
              <li>
+
                 Kim et al., &ldquo;Preparation of flavor-enhancing yeast extract
+
                using a Saccharomyces cerevisiae strain with high RNA
+
                content&rdquo;, Korean J Food Sci Technol, 31 (2) (1999), pp.
+
                475-481.
+
              </li>
+
              <li>
+
                T.L. Babayan, M.G. Bezrukov, &ldquo;Autolysis in yeasts&rdquo;,
+
                Acta Biotechnol, 5 (2) (1985), pp. 129-136.
+
              </li>
+
              <li>
+
                van der Rest, M E et al. &ldquo;The plasma membrane of
+
                Saccharomyces cerevisiae: structure, function, and
+
                biogenesis.&rdquo; Microbiological reviews vol. 59,2 (1995):
+
                304-22.
+
              </li>
+
              <li>
+
                Takeda, &ldquo;Classification of Chlorella strains by cell wall
+
                sugar composition&rdquo; Phytochemistry, vol. 27, 12, (1988),
+
                pp. 3823-3826.
+
              </li>
+
              <li>
+
                [4} Takeda, &ldquo;Classification of Chlorella strains by cell
+
                wall sugar composition&rdquo; Phytochemistry, vol. 27, 12,
+
                (1988), pp. 3823-3826.
+
              </li>
+
            </ol>
+
          </div>
+
        </div>
+
        <br /><br />
+
        <div id="cdwcorrelation" class="section-container">
+
          <h2 class="title is-3">
+
            CDW correlation of algae <em>Chlorella vulgaris</em> Results
+
          </h2>
+
          <p>
+
            By plotting the measured optical densities against the means of the
+
            calculated cellular dry weights, a correlation was obtained. It is
+
            shown in the following figure.
+
          </p>
+
          <br />
+
          <img
+
            style="display: block; max-width: 500px; margin: 0 auto;"
+
            src="https://2019.igem.org/wiki/images/a/ad/T--Stuttgart--FigureOD-CDW_correlation_of_algae_Chlorella_vulgaris_Results1.png"
+
          />
+
          <small
+
            >Figure 1 - OD-CDW correlation of the algae
+
            <em>Chlorella vulgaris</em>. Mean of cellular dry weight in g/L
+
            (n=2) was plotted against the measured optical density at 750 nm.
+
            Trend line was shown in red.
+
          </small>
+
          <br />
+
          <br />
+
          <br />
+
          <p>
+
            The trend line in figure 1 is poorly matching the trend of the
+
            measurement points. For this reason, the correlation curve was
+
            rejected. For improvement of this experiment, measurements should be
+
            performed only by one experimenter to reduce pipetting errors or
+
            other handling mistakes. Also the measurements should be taken over
+
            a longer time period to gain more trust worthy results.
+
          </p>
+
          <br />
+
        </div>
+
        <br /><br />
+
        <div id="cdwodcorrelation" class="section-container">
+
          <h2 class="title is-3">CDW-OD correlation by dilution Results</h2>
+
          In the following table you can see the calculated cell dry weights
+
          with the corresponding optical density of the tubes. Some tubes broke
+
          during the experiment so corresponding measurements could not occur.
+
          <br />
+
          <br />
+
          <div class="columns">
+
            <div class="column">
+
              <small
+
                >Table 2 -Calculated values of the cellular dry weight in g/l
+
                with the corresponding optical density measured at 750 nm.
+
              </small>
+
  
              <table class="table is-fullwidth">
+
                 <br/>
                 <thead>
+
                 <br/>
                  <tr>
+
                 <p>
                    <th>OD</th>
+
                    One can tell from the coloring of the samples in figure 2, that the carbohydrate concentration
                    <th>CDW[g/l]</th>
+
                     should differ
                  </tr>
+
                     very slightly between the samples pH3, pH6, bead mill extraction +pH3 and bead mill extraction +pH6.
                 </thead>
+
                     Due to
                 <tbody>
+
                     the cloudiness of the control sample, a background corrected optical density could not be
                  <tr>
+
                     determined.
                     <td>4.87</td>
+
                     Therefore, the coloring scheme served as evaluation for successful carbohydrate determination.
                     <td>0.98</td>
+
                </p>
                  </tr>
+
                <p>
                  <tr>
+
                     Hereby, bead-mill (RKM) with subsequent autolysis at pH3 was determined to be the method of choice.
                     <td>4.41</td>
+
                </p>
                     <td>0.88</td>
+
                <br/><br/>
                  </tr>
+
                <div class="notification">
                  <tr>
+
                     <h3 class="title is-5">References</h3>
                     <td>4.44</td>
+
                     <ol>
                     <td>0.91</td>
+
                        <li>
                  </tr>
+
                            Kim et al., &ldquo;Preparation of flavor-enhancing yeast extract using a Saccharomyces
                  <tr>
+
                            cerevisiae strain
                     <td>4.02</td>
+
                            with high RNA content&rdquo;, Korean J Food Sci Technol, 31 (2) (1999), pp. 475-481.
                    <td>0.8</td>
+
                        </li>
                  </tr>
+
                        <li>
                  <tr>
+
                            T.L. Babayan, M.G. Bezrukov, &ldquo;Autolysis in yeasts&rdquo;, Acta Biotechnol, 5 (2)
                     <td>3.92</td>
+
                            (1985), pp.
                     <td>0.82</td>
+
                            129-136.
                  </tr>
+
                        </li>
                  <tr>
+
                        <li>
                    <td>3.52</td>
+
                            van der Rest, M E et al. &ldquo;The plasma membrane of Saccharomyces cerevisiae: structure,
                    <td>0.68</td>
+
                            function,
                  </tr>
+
                            and biogenesis.&rdquo; Microbiological reviews vol. 59,2 (1995): 304-22.
                  <tr>
+
                        </li>
                    <td>3.57</td>
+
                        <li>
                    <td>0.71</td>
+
                            Takeda, &ldquo;Classification of Chlorella strains by cell wall sugar composition&rdquo;
                  </tr>
+
                            Phytochemistry,
                  <tr>
+
                            vol. 27, 12, (1988), pp. 3823-3826.
                    <td>3.03</td>
+
                        </li>
                    <td>0.57</td>
+
                        <li>
                  </tr>
+
                            [4} Takeda, &ldquo;Classification of Chlorella strains by cell wall sugar composition&rdquo;
                  <tr>
+
                            Phytochemistry, vol. 27, 12, (1988), pp. 3823-3826.
                    <td>2.65</td>
+
                        </li>
                    <td>0.49</td>
+
                     </ol>
                  </tr>
+
                 </div>
                  <tr>
+
                    <td>2.8</td>
+
                    <td>0.5</td>
+
                  </tr>
+
                  <tr>
+
                    <td>2.43</td>
+
                    <td>0.48</td>
+
                  </tr>
+
                  <tr>
+
                    <td>2.56</td>
+
                    <td>0.46</td>
+
                  </tr>
+
                  <tr>
+
                    <td>2.29</td>
+
                    <td>0.4</td>
+
                  </tr>
+
                  <tr>
+
                     <td>2.28</td>
+
                    <td>0.4</td>
+
                  </tr>
+
                 </tbody>
+
              </table>
+
 
             </div>
 
             </div>
             <div class="column">
+
            <br/><br/>
              <p>
+
             <div id="cdwcorrelation" class="section-container">
                The cellular dry weight in g/l was then plotted against the
+
                <h2 class="title is-3">CDW correlation of algae <em>Chlorella vulgaris</em> Results</h2>
                 optical density measured at 750 nm. The plot with the
+
                 <p>
                corresponding trend line is shown in the following figure.
+
                    By plotting the measured optical densities against the means of the calculated cellular dry weights,
 
+
                    a
 +
                    correlation was obtained. It is shown in the following figure.
 +
                </p>
 +
                <br/>
 
                 <img
 
                 <img
                  style="display: block; max-width: 500px; margin: 0 auto;"
+
                        style="display: block; max-width: 500px; margin: 0 auto;"
                  src="https://2019.igem.org/wiki/images/d/df/T--Stuttgart--FigureOD-CDW_correlation_of_Chlorella_vulgaris_by_dilution_Results1.png"
+
                        src="https://2019.igem.org/wiki/images/a/ad/T--Stuttgart--FigureOD-CDW_correlation_of_algae_Chlorella_vulgaris_Results1.png"
 
                 />
 
                 />
 
                 <small
 
                 <small
                  >Figure 1 - Cellular dry weight in g/l is plotted against the
+
                >Figure 1 - OD-CDW correlation of the algae <em>Chlorella vulgaris</em>. Mean of cellular dry weight in
                  optical density measured at 750 nm. The linear fit is shown in
+
                    g/L
                  blue together with its formula.</small
+
                    (n=2) was plotted against the measured optical density at 750 nm. Trend line was shown in red.
                >
+
                </small>
                <br />
+
                <br/>
                <br />
+
                <br/>
              </p>
+
                <br/>
 +
                <p>
 +
                    The trend line in figure 1 is poorly matching the trend of the measurement points. For this reason,
 +
                    the
 +
                    correlation curve was rejected. For improvement of this experiment, measurements should be performed
 +
                    only by
 +
                    one experimenter to reduce pipetting errors or other handling mistakes. Also the measurements should
 +
                    be
 +
                    taken over a longer time period to gain more trust worthy results.
 +
                </p>
 +
                <br/>
 +
            </div>
 +
            <br/><br/>
 +
            <div id="cdwodcorrelation" class="section-container">
 +
                <h2 class="title is-3">CDW-OD correlation by dilution Results</h2>
 +
                In the following table you can see the calculated cell dry weights with the corresponding optical
 +
                density of
 +
                the tubes. Some tubes broke during the experiment so corresponding measurements could not occur.
 +
                <br/>
 +
                <br/>
 +
                <div class="columns">
 +
                    <div class="column">
 +
                        <small
 +
                        >Table 2 -Calculated values of the cellular dry weight in g/l with the corresponding optical
 +
                            density
 +
                            measured at 750 nm.
 +
                        </small>
 +
 
 +
                        <table class="table is-fullwidth">
 +
                            <thead>
 +
                            <tr>
 +
                                <th>OD</th>
 +
                                <th>CDW[g/l]</th>
 +
                            </tr>
 +
                            </thead>
 +
                            <tbody>
 +
                            <tr>
 +
                                <td>4.87</td>
 +
                                <td>0.98</td>
 +
                            </tr>
 +
                            <tr>
 +
                                <td>4.41</td>
 +
                                <td>0.88</td>
 +
                            </tr>
 +
                            <tr>
 +
                                <td>4.44</td>
 +
                                <td>0.91</td>
 +
                            </tr>
 +
                            <tr>
 +
                                <td>4.02</td>
 +
                                <td>0.8</td>
 +
                            </tr>
 +
                            <tr>
 +
                                <td>3.92</td>
 +
                                <td>0.82</td>
 +
                            </tr>
 +
                            <tr>
 +
                                <td>3.52</td>
 +
                                <td>0.68</td>
 +
                            </tr>
 +
                            <tr>
 +
                                <td>3.57</td>
 +
                                <td>0.71</td>
 +
                            </tr>
 +
                            <tr>
 +
                                <td>3.03</td>
 +
                                <td>0.57</td>
 +
                            </tr>
 +
                            <tr>
 +
                                <td>2.65</td>
 +
                                <td>0.49</td>
 +
                            </tr>
 +
                            <tr>
 +
                                <td>2.8</td>
 +
                                <td>0.5</td>
 +
                            </tr>
 +
                            <tr>
 +
                                <td>2.43</td>
 +
                                <td>0.48</td>
 +
                            </tr>
 +
                            <tr>
 +
                                <td>2.56</td>
 +
                                <td>0.46</td>
 +
                            </tr>
 +
                            <tr>
 +
                                <td>2.29</td>
 +
                                <td>0.4</td>
 +
                            </tr>
 +
                            <tr>
 +
                                <td>2.28</td>
 +
                                <td>0.4</td>
 +
                            </tr>
 +
                            </tbody>
 +
                        </table>
 +
                    </div>
 +
                    <div class="column">
 +
                        <p>
 +
                            The cellular dry weight in g/l was then plotted against the optical density measured at 750
 +
                            nm. The plot
 +
                            with the corresponding trend line is shown in the following figure.
 +
 
 +
                            <img
 +
                                    style="display: block; max-width: 500px; margin: 0 auto;"
 +
                                    src="https://2019.igem.org/wiki/images/d/df/T--Stuttgart--FigureOD-CDW_correlation_of_Chlorella_vulgaris_by_dilution_Results1.png"
 +
                            />
 +
                            <small
 +
                            >Figure 1 - Cellular dry weight in g/l is plotted against the optical density measured at
 +
                                750 nm. The
 +
                                linear fit is shown in blue together with its formula.</small
 +
                            >
 +
                            <br/>
 +
                            <br/>
 +
                        </p>
  
              <p>
+
                        <p>
                The slope of the formula further been used for fast estimation
+
                            The slope of the formula further been used for fast estimation of the CDW by measuring the
                of the CDW by measuring the optical density at 750 nm.
+
                            optical
              </p>
+
                            density at 750 nm.
 +
                        </p>
 +
                    </div>
 +
                </div>
 
             </div>
 
             </div>
          </div>
 
 
         </div>
 
         </div>
      </div>
 
 
     </div>
 
     </div>
  </div>
+
</div>
 
</html>
 
</html>

Revision as of 21:04, 20 October 2019

Project

Results

qRT-PCR for the relative quantification of specific tRNA-species

Alongside with the generation of a climate-friendly medium, the goal of our project PhyCoVi was to optimize the strain Vibrio natriegens for a potential use in the biotech industry. The optimization is performed on the genomic level to increase the intracellular availability of tRNA species. As a result, the strain’s performance to express heterologous proteins is enhanced.


A method needs to be developed to quantify individual tRNA species specifically to prove the increased expression not only on the protein level.  Multiple methods can be found to quantify non-coding RNA 1, 2 or total tRNA concentration 3, 4. Whereas finding a well-established method to quantify single tRNA species specifically is in vain. The only method paper was published in the journal “RNA biology” in 2015 by Honda et al.: “Four-leaf clover qRT-PCR: A convenient method for selective quantification of mature tRNA” 5. The authors of this paper removed the amino acid at the 3’ end followed by hybridization and ligation with a DNA/RNA hybrid stem loop creating a “four-leaf clover” shaped appearance of the tRNA ligation product. The stem loop adaptor contained a TaqMan probe binding site. During the qPCR the TaqMan probe was cut by exonuclease function of the used polymerase resulting in emission of fluorescence.


Building on the work of Honda et al. we developed a new and simplified method for relative quantification of specific tRNA species without the necessity of TaqMan probes. Instead using a DNA/RNA hybrid stem loop we used a linear DNA/RNA construct as adaptor.


The first step is to isolate RNA with a length of < 200 nt from cultured V. natriegens cells. Then, the amino acid bound to the 3’ end needs to be removed by a deacylation reaction. This results in a sticky end, where a linear RNA/DNA hybrid adaptor can be ligated, which is complementary to the 3’ end overhang. Although different tRNAs show differences in length and sequence, the last three nucleotides at the 3’ end are the same for all tRNA species. The ligated adaptor contains a binding site for the forward-primer, which is identical for all tRNAs (unspecific primer). We used T4-RNA-ligase 2 that requires ATP. For this reason, a polynucleotide kinase was necessary to carry out a phosphorylation reaction at the 5’ end.


To amplify single tRNA species specifically, we distinguished between two options. First option was using the specific tRNA primer in a reverse transcription to convert the whole tRNA pool to cDNA. Following RNase H digestion results in pure cDNA of the desired tRNA species.

Later the desired tRNA species is amplified during a qPCR by using the specific reverse primer and the unspecific adaptor primer.

During qPCR a DNA-intercalating fluorescence dye (Green DNA dye) allows for relative quantification: Green DNA dye binds to double stranded DNA and absorbs blue light and emits green light. The more double stranded DNA is generated, the higher the resulting fluorescence. And the higher the concentration of the template in the sample the faster the fluorescence exceeds the threshold. The number of cycles at which this happens is called the threshold cycle (Ct). (e.g. if sample A showed a Ct of 8 and sample B showed a Ct of 11, sample A contained 23 = 8 times more template.)


After running a DNA gel, we noticed that the obtained amplification products did not show the expected length. This may have been a result of distinct secondary structures of the tRNA species: the reverse transcription reaction was performed at 42 °C which is the enzyme’s optimum working temperature. However, this temperature is not high enough to prevent secondary structures or to break them up. Therefore, areas with secondary structures may have been inaccessible for the reverse transcriptase resulting in shorter cDNA fragments.


For this reason, we tested a second option to amplify single tRNA species specifically. A modified polymerase together with the specific reverse primer can be used to amplify the desired tRNA species using RNA as a template. This modified polymerase works at temperatures around 65 °C and can use both RNA and DNA as a template. The reverse transcription reaction is thus not needed as a consecutive step anymore. Moreover, the modified enzyme creates the specific cDNA from RNA directly and the high temperature prevents secondary structures. The relative quantification based on Ct values is the same as in the option described before.



References

  1. I. A. Babarinde, Y. Li, A. P. Hutchins (2019) Computational Methods for Mapping, Assembly and Quantification for Coding and Non-coding Transcripts, Computational and Structural Biotechnology Journal, Vol. 17, pp 628-637

 

  1. D. Jacob, K. Thüring, A. Galliot, V. Marchand, A. Galvanin, A. Ciftci, K. Scharmann, M. Stock, J.‐Y. Roignant, S.A. Leidel, Y. Motorin, R. Schaffrath, R. Klassen, M. Helm (2019) Absolute Quantification of Noncoding RNA by Microscale Thermophoresis, Angewandte Chemie International Edition, Vol. 58, pp 9565 – 9569

 

  1. T. S. Stenum, M. A. Sørensen, S. L. Svenningsen (2017) Quantification of the Abundance and Charging Levels of Transfer RNAs in Escherichia coli. Journal of Visual Experiments, Issue 126, e56212

 

  1. Y. Guo, A. Bosompem, S.Mohan, B. Erdogan, F.Ye, K. C. Vickers, Q. Sheng, S. Zhao, C. Li, P.-F. Su, M. Jagasia, S. A. Strickland, E. A. Griffiths, A. S. Kim (2015) Transfer RNA detection by small RNA deep sequencing and disease association with myelodysplastic syndromes, BMC Genomics, 16:727

 

  1. S. Honda, M. Shigematsu, K. Morichika, A. G. Telonis, Y. Kirino (2015) Four-leaf clover qRT-PCR: A convenient method for selective quantification of mature tRNA, RNA Biology, Vol. 12, pp 501 – 508

Cloning of tRNA fragments into pSB1C3

The tRNA fragments were synthesized by IDT and amplified by PCR according to the PCR protocol (Protocol_PCR.pdf). The amplified tRNA fragments were validated via agarose gel electrophoresis (Stuttgart--Protocol_Agarose_Gel.pdf). Looking at Figure 1 all tRNA fragments showed a clear band at the desired height.

Figure 1: Amplified tRNA fragments. The tRNA fragments AGA, CGC, TGC, TCC and AGG were amplified via PCR. The PCR products were separated by agarose gel electrophoresis. A 2% agarose gel was prepared and 10 µL were loaded for each probe ((1): AGA, (2): CGC, (3): TGC, (4): TCC, (5): AGG). 3 µL of Hyberladder 1 kb Bioline were loaded as a marker (M). The gel was run at 90 V for 1 hour and stained using MidoriGreen.

In a first step, the tRNA fragments were cloned into the pSB1C3 vector. The pSB1C3 and the tRNA fragments AGA, AGG, CGG, TGC, TCC and a combined tRNA fragment containing all 5 tRNAs were digested using the restriction enzymes XbaI and SpeI.
After purification, ( Protocol_Clean_and_Concentrate.pdf) the digested fragments were ligated using the T4 DNA ligase (see Protocol_BioBrick_Cloning.pdf). The ligated DNA fragments were transformed into DH5α ( Protocol_Transformation.pdf). The plasmid obtained from the colonies ( Protocol_Plasmid_Preparation.pdf) was digested with XbaI to gain linear Plasmid and separated by agarose gel electrophoresis ( Protocol_Agarose_Gel.pdf). Looking at Figure 2 the obtained plasmids showed no insert, only pSB1C3. Also visible is, that despite the digestion, circular, supercoiled and open circular structures of the plasmid are still present. This indicates inefficient digestion by the restriction enzymes.


Figure 2 - Cloning of tRNA fragments into pSB1C3. The pSB1C3 and the tRNA fragments were digested using the restriction enzymes XbaI and SpeI. After purification, the digested fragments were ligated using the T4 DNA ligase. The ligated DNA fragments were transformed into DH5α and subsequently prepared. The obtained plasmids were digested with XbaI before the agarose gel electrophoresis. A 1% agarose gel was prepared and 10 µL were loaded for each probe ((1): AGA, (2): AGG, (3): CGG, (4): TGC, (5): TCC, (6): Combined tRNA fragment). As a control (C) the linear pSB1C3 was loaded. 3 µL of GeneRuler, 1kb Plus DNA Ladder was loaded as a marker (M). The gel was run at 90 V for 1 hour and stained using GelRed.

Since the cloning showed inefficient digestion by the enzymes XbaI and SpeI, it was performed again with the enzymes EcoRI-HF and PstI. The pSB1C3 and the tRNA fragments AGA, AGG, CGG, TGC, TCC and a combined tRNA fragment were digested using the restriction enzymes EcoRI-HF and PstI.
After purification, ( Protocol_Clean_and_Concentrate.pdf) the digested fragments were ligated using the T4 DNA ligase (see Protocol_BioBrick_Cloning.pdf). The ligated DNA fragments were transformed into DH5α cells ( Protocol_Transformation.pdf). The plasmid obtained from the colonies ( Protocol_Plasmid_Preparation.pdf) was digested with EcoRI-HF to gain linear Plasmid and separated by agarose gel electrophoresis (Protocol_Agarose_Gel.pdf). The agarose gel revealed no successful cloning as all obtained plasmids showed no insert, only pSB1C3 (data not shown).


Cloning of tRNA fragments into ptRNA_backbone via BioBrick Cloning

In a first step, the self-designed linear ptRNA_backbone from IDT was ligated according to the NEB Ligation Protocol with T4 DNA Ligase (see T--Stuttgart--Blunt_End_Ligation.pdf). Afterward, the ligated ptRNA-backbone was transformed in E. coli DH5a cells (see Protocol_Transformation.pdf). Successfully transformed DH5α cells were selected on LB agar plates containing tetracycline. The next day the circular ptRNA_backbone was prepared from the colonies according to the Plasmid Preparation protocol ( Protocol_Plasmid_Preparation.pdf). The plasmid obtained from the colonies was digested with EcoRI-HF to gain linear Plasmid and separated by agarose gel electrophoresis ( Protocol_Agarose_Gel.pdf). Looking at Figure 3 all plasmids run at the desired length which corresponds to the length of the ptRNA_backbone 2159 bp.



Figure 3 -Cloning of ptRNA_backbone. The linear ptRNA_backbone fragment from IDT was ligated using the T4 DNA Ligase. The ligated ptRNA-backbone was transformed into DH5α and subsequently prepared. The obtained plasmids were digested with EcoRI-HF before the agarose gel electrophoresis. A 1% agarose gel was prepared and 10 µL were loaded for each probe ((1): ptRNA_backbone gBlock from IDT, (2): colony 2, (3): colony 3, (4): colony 4, (5): colony 5, (6): colony 6). 3 µL of GeneRuler, 1kb Plus DNA Ladder was loaded as a marker (M). The gel was run at 90 V for 1 hour and stained using GelRed.

The ptRNA_backbone and the previously amplified tRNA fragments AGA, AGG, CGG, TGC, TCC and a combined tRNA fragment were digested using the restriction enzymes EcoRI-HF and PstI. After purification, ( Protocol_Clean_and_Concentrate.pdf) the digested fragments were ligated using the T4 DNA ligase (see Protocol_BioBrick_Cloning.pdf). The ligated DNA fragments were transformed into DH5α ( Protocol_Transformation.pdf). The plasmid obtained from the colonies ( Protocol_Plasmid_Preparation.pdf) was digested with EcoRI-HF to gain linear Plasmid and separated by agarose gel electrophoresis ( Protocol_Agarose_Gel.pdf). Figure 4 reveals no successful cloning as all obtained Plasmids show no insert, only ptRNA_backbone.

Figure 4 - Cloning of tRNA fragments into ptRNA_backbone. The ptRNA_backbone and the tRNA fragments were digested using the restriction enzymes EcoRI-HF and PstI. After purification, the digested fragments were ligated using the T4 DNA ligase. The ligated DNA fragments were transformed into DH5α and subsequently prepared. The obtained plasmids were digested with EcoRI-HF before the agarose gel electrophoresis. A 1% agarose gel was prepared and 10 µL were loaded for each probe ((1): AGA, (2): AGG, (3): CGG, (4): TGC, (5): TCC, (6): Combined tRNA fragment). As a control (C) the linear ptRNA_backbone was loaded. 3 µL of GeneRuler, 1kb Plus DNA Ladder was loaded as a marker (M). The gel was run at 90 V for 1 hour and stained using GelRed.

This BioBrick cloning was repeated several times using different EcoRI-HF and PstI stocks. Following transformation in DH5α revealed no successful cloning. The colonies obtained showed no insert in an agarose gel and only ptRNA_backbone. Following transformation in competent Vibrio natriegens cells also revealed no successful cloning (data not shown).



Cloning of tRNA fragments into ptRNA_backbone via Gibson Assembly

Cloning of tRNA fragments into ptRNA_backbone was also performed using Gibson Assembly. Gibson Assembly was conducted according to the protocol Gibson Assembly ( Protocol_Gibson_Assembly.pdf). The Gibson reaction was transformed into competent DH5α cells ( Protocol_Transformation.pdf). The plasmid obtained from the colonies ( Protocol_Plasmid_Preparation.pdf) was digested with EcoRI-HF to gain linear Plasmid and separated by agarose gel electrophoresis ( Protocol_Agarose_Gel.pdf). Figure 5 reveals no successful cloning as all obtained Plasmids show no insert, only ptRNA_backbone.

Figure 5 -Gibson Assembly of tRNA fragments into ptRNA_backbone. Gibson Assembly was performed according to the Gibson Assembly Protocol. The Gibson Assembly reaction was transformed into DH5α and subsequently prepared. The obtained plasmids were digested with EcoRI-HF before the agarose gel electrophoresis. A 1% agarose gel was prepared and 10 µL were loaded for each probe ((1): AGA, (2): AGG, (3): CGG, (4): TGC, (5): TCC). As a control (C) the linear ptRNA_backbone was loaded. 3 µL of GeneRuler, 1kb Plus DNA Ladder was loaded as a marker (M). The gel was run at 90 V for 1 hour and stained using GelRed.

Cloning of tRNA fragments into ptRNA_backbone via Gibson Assembly was repeated with another Gibson Assembly Master Mix and revealed no successful cloning. The colonies obtained showed no insert in an agarose gel and only ptRNA_backbone (data not shown).



Isolation of Vibrio natriegens DSM 759 genome chr.1 and amplification of tRNAs

As an alternative to cloning of tRNA fragments provided by IDT, the tRNAs AGA, AGG, CGG, TGC and TCC were amplified from the Vibrio natriegens DSM 759 genome. Therefore, the Vibrio natriegens DSM 759 genome chr.1 was isolated according to the gDNA Extraction protocol ( gDNA_extraction.pdf). The tRNA fragments AGA, AGG, CGG, TGC, TCC were amplified from the Vibrio natriegens DSM 759 genome via PCR with appropriate primers (see Protocol_PCR.pdf). Looking at Figure 6 all tRNA fragments showed a clear band at the desired height. The tRNA fragments were extracted from the agarose gel according to the gel extraction protocol ( Protocol_Gel_Extraction.pdf).



Figure 6: Amplification of tRNAs from the Vibrio natriegens DSM 759 genome. The Vibrio natriegens DSM 759 genome chr.1 was isolated according to the Protocol gDNA Extraction. The tRNA fragments AGA, AGG, CGG, TGC, TCC were amplified from the Vibrio natriegens DSM 759 genome via PCR with appropriate primers. A 1.5 % agarose gel was prepared and 10 µL were loaded for each probe ((1): AGA, (2): AGG, (3): CGG, (4): TGC, (5): TCC). 3 µL of GeneRuler, 1kb Plus DNA Ladder was loaded as a marker (M). The gel was run at 90 V for 1 hour and stained using GelRed.

Cloning of tRNA fragments (amplified from Vibrio natriegens DSM 759 genome) into ptRNA_backbone via BioBrick Cloning

The ptRNA_backbone and the previously amplified tRNA fragments AGA, AGG, CGG, TGC, TCC from the Vibrio natriegens DSM 759 genome were digested using the restriction enzymes EcoRI-HF and PstI. After purification, ( Protocol_Clean_and_Concentrate.pdf) the digested fragments were ligated using the T4 DNA ligase (see Protocol_BioBrick_Cloning.pdf). The ligated DNA fragments were transformed into competent DH5α cells ( Protocol_Transformation.pdf). The plasmid obtained from the colonies ( Protocol_Plasmid_Preparation.pdf) was digested with EcoRI-HF and PstI to release inserted tRNA fragments from the ptRNA_backbone and gain linear plasmid. The DNA fragments were separated by agarose gel electrophoresis ( Protocol_Agarose_Gel.pdf). Looking at Figure 7 no insert band was visible for the obtained plasmids, only ptRNA_backbone, suggesting no successful cloning.

Figure 7: BioBrick cloning of tRNA fragments into ptRNA_backbone. The tRNA fragments were previously amplified from the Vibrio natriegens DSM 759 genome. The ptRNA_backbone and the tRNA fragments were digested using the restriction enzymes EcoRI-HF and PstI. After purification, the digested fragments were ligated using the T4 DNA ligase. The ligated DNA fragments were transformed into DH5α and subsequently prepared. The obtained plasmids were digested with EcoRI-HF and PstI before the agarose gel electrophoresis. A 1% agarose gel was prepared and 10 µL were loaded for each probe ((1): AGA, (2): AGG, (3): CGG, (4): TGC, (5): ACC). As a control (C) the linear ptRNA_backbone was loaded. 3 µL of GeneRuler, 1kb Plus DNA Ladder was loaded as a marker (M). The gel was run at 90 V for 1 hour and stained using GelRed.

Following transformation in competent Vibrio natriegens cells also revealed no successful cloning (data not shown).



Cloning of tRNA fragments (amplified from Vibrio natriegens DSM 759 genome) into ptRNA_backbone via NEBuilder HiFi DNA Assembly

The tRNA fragments were previously amplified from Vibrio natriegens DSM 759 genome. The NEBuilder HiFi DNA Assembly was performed according to the Protocol NEBuilder HiFi DNA Assembly (https://2019.igem.org/wiki/images/2/25/T--Stuttgart--Protocols_NEBuilder_HiFi_DNA_Assembly.pdf). Following transformation into competent DH5α cells revealed no successful cloning as no colonies were obtained. Following transformation in competent Vibrio natriegens cells also revealed no successful cloning (data not shown).



Cloning of tRNA fragments (amplified from Vibrio natriegens DSM 759 genome) into ptRNA_backbone via Gibson Assembly

Gibson Assembly was performed according to the protocol Gibson Assembly ( https://2019.igem.org/wiki/images/6/6c/T--Stuttgart--Protocol_Gibson_Assembly.pdf). Due to the orientation in the Vibrio natriegens DSM 759 genome only the tRNA fragments AGG and TGC could be used for Gibson Assembly. The Gibson reaction was transformed into competent DH5α cells ( Protocol_Transformation.pdf). The plasmid obtained from the colonies ( Protocol_Plasmid_Preparation.pdf) was digested with EcoRI-HF and PstI to release inserted tRNA fragments from the ptRNA_backbone and gain linear plasmid. The DNA fragments were separated by agarose gel electrophoresis ( Protocol_Agarose_Gel.pdf). Looking at Figure 8 no insert band was visible for the obtained plasmids, only ptRNA_backbone, suggesting no successful cloning.

Figure 8: Gibson Assembly of tRNA fragments into ptRNA_backbone. Gibson Assembly was performed according to the Gibson Assembly Protocol. The tRNA fragments were previously amplified from the Vibrio natriegens DSM 759 genome. The Gibson Assembly reaction was transformed into DH5α and subsequently prepared. The obtained plasmids were digested with EcoRI-HF and PstI before the agarose gel electrophoresis. A 1% agarose gel was prepared and 10 µL were loaded for each probe ((1): AGG colony 1, (2): AGG colony 2, (3): TGC colony 1, (4): TGC colony 2). 3 µL of GeneRuler, 1kb Plus DNA Ladder was loaded as a marker (M). The gel was run at 90 V for 1 hour and stained using GelRed.

Cloning of tRNA fragments into ptRNA_backbone via Gibson Assembly was repeated with another Gibson Assembly Master Mix and revealed no successful cloning. The colonies obtained showed no insert in an agarose gel and only ptRNA_backbone. Following transformation of the Gibson reaction in competent Vibrio natriegens cells also revealed no successful cloning (data not shown).



Media based on algae: first tests determining important substrates

Medium based on LB

To first determine whether the extract of chlorella vulgaris was a substitute for yeast extract, LB medium and medium containing chlorella vulgaris extract instead of yeast extract were produced.

  1. Media were produced (Protocol_media_first_experiments.pdf).
  2. Media were inoculated with escherichia coli or vibrio natriegens.
  3. After the over night culture, the turbidity of the tubes was observed.

Result: Growth of both bacteria was observed in both media.


Medium without tryptone

To determine whether chlorella vulgaris extract was able to substitute tryptone as a medium component, additionally, media containing different concentrations of NaCl chlorella vulgaris extract and yeast extract were prepared.

  1. Media were produced (Protocol_media_first_experiments.pdf).
  2. Media were inoculated with vibrio natriegens.
  3. After the overnight culture, the turbidity of the tubes was observed.

Result: No growth was detectable in media without tryptone.



Autolysis in combination with bead-milling Results

Free amino acid estimation with rFAN assay

Samples from Experiment Cell_extraction_with_autolysis_combined_with_bead-milling.pdf were used for the analysis.


Yeast extract is mostly obtained by autolysis 1. In autolysis cells digest their own cell compounds with their own enzymes 2. The idea was to transfer this commonly used principal on algae. Therefore, C. vulgaris and C. sorokiniana were heated to 50 °C in alkaline or acidic environment for 41 h. To further crack the cell wall, both algae were treated with bead-milling afterwards. To quantify the success of cell wall disruption free amino acids were measured with rFAN-assay.


The yield of free amino acids was set into relation with the amount of biomass used in the experiment (figure 1).

Figure 1 -Autolysis and subsequent bead-milling of algae C. vulgaris and C. sorokiniana. The percentage of free amino acids [%] relates to the biomass used in the experiment.

The highest amounts of free amino acids were reached with yeast at pH 12 with 4.85 %. Both algae showed very low yield in free amino acids. The best results showed C. sorokiniana at pH 12. It is possible, that the amount of glass beads and the size of the glass beads were to little, which led to less cell wall disruption. Therefore, amino acids would have been retained within the cells. This would explain the little amounts of free amino acids achieved with this method. Also, C. vulgaris and C. sorokinia have a cell wall, in contrast to yeast 3>. Cell walls are harder to break, than a plasma membrane. This could explain the difference between the yeast samples and the algae samples. Due to the low yield in free amino acids, it was decided to investigate other methods for cell extraction of algae.



Anthrone assay to Determine Soluble Carbohydrate Concentration

Similar to the rFAN assay the anthrone assay is a method to detect free monosaccharides in a liquid. Therefor samples from the experiment Experiments_AnthroneAssay.pdf were analyzed. Hereby a calibration curve with known amounts of glucose is created (Figure 2, left side). This calibration curve creates the possibility to calculate the sugar concentration of the samples (Figure 2, right side).

Figure 2: Pictures of the anthrone calibration curve as well as the anthrone assay of samples. For the calibration curve known amounts of glucose is dissolved in water and the optical density at 620 nm is measured (left side). This can be used to determine the monosaccharide concentration of anthone treated samples which previously underwent autolysis (pH3 or pH6) with or without subsequent bead-mill treatment (RKM) (right side).

One can tell from the coloring of the samples in figure 2, that the carbohydrate concentration should differ very slightly between the samples pH3, pH6, bead mill extraction +pH3 and bead mill extraction +pH6. Due to the cloudiness of the control sample, a background corrected optical density could not be determined. Therefore, the coloring scheme served as evaluation for successful carbohydrate determination.

Hereby, bead-mill (RKM) with subsequent autolysis at pH3 was determined to be the method of choice.



References

  1. Kim et al., “Preparation of flavor-enhancing yeast extract using a Saccharomyces cerevisiae strain with high RNA content”, Korean J Food Sci Technol, 31 (2) (1999), pp. 475-481.
  2. T.L. Babayan, M.G. Bezrukov, “Autolysis in yeasts”, Acta Biotechnol, 5 (2) (1985), pp. 129-136.
  3. van der Rest, M E et al. “The plasma membrane of Saccharomyces cerevisiae: structure, function, and biogenesis.” Microbiological reviews vol. 59,2 (1995): 304-22.
  4. Takeda, “Classification of Chlorella strains by cell wall sugar composition” Phytochemistry, vol. 27, 12, (1988), pp. 3823-3826.
  5. [4} Takeda, “Classification of Chlorella strains by cell wall sugar composition” Phytochemistry, vol. 27, 12, (1988), pp. 3823-3826.


CDW correlation of algae Chlorella vulgaris Results

By plotting the measured optical densities against the means of the calculated cellular dry weights, a correlation was obtained. It is shown in the following figure.


Figure 1 - OD-CDW correlation of the algae Chlorella vulgaris. Mean of cellular dry weight in g/L (n=2) was plotted against the measured optical density at 750 nm. Trend line was shown in red.


The trend line in figure 1 is poorly matching the trend of the measurement points. For this reason, the correlation curve was rejected. For improvement of this experiment, measurements should be performed only by one experimenter to reduce pipetting errors or other handling mistakes. Also the measurements should be taken over a longer time period to gain more trust worthy results.




CDW-OD correlation by dilution Results

In the following table you can see the calculated cell dry weights with the corresponding optical density of the tubes. Some tubes broke during the experiment so corresponding measurements could not occur.

Table 2 -Calculated values of the cellular dry weight in g/l with the corresponding optical density measured at 750 nm.
OD CDW[g/l]
4.87 0.98
4.41 0.88
4.44 0.91
4.02 0.8
3.92 0.82
3.52 0.68
3.57 0.71
3.03 0.57
2.65 0.49
2.8 0.5
2.43 0.48
2.56 0.46
2.29 0.4
2.28 0.4

The cellular dry weight in g/l was then plotted against the optical density measured at 750 nm. The plot with the corresponding trend line is shown in the following figure. Figure 1 - Cellular dry weight in g/l is plotted against the optical density measured at 750 nm. The linear fit is shown in blue together with its formula.

The slope of the formula further been used for fast estimation of the CDW by measuring the optical density at 750 nm.