Team:Sorbonne U Paris/Safety


SAFE PROJECT DESIGN

First, we worked safely and securely with our organism. Indeed, we used the microalga Chlamydomonas reinhardtii strain UVM4 as the chassis for our project. This is a non-pathogenic strain classified as a GRAS organism 1, therefore there were no risks for us and our colleagues in the laboratory. Then, we worked safely and securely with our parts. Indeed, we have chosen to use already characterized sequences from a safe organism, the african oil palm Elaeis guineensis, so this is highly unlikely that our parts are toxic for humans or encode a protein that is toxic by itself. Therefore we could handle our parts safely. However, if we imagined that our project was fully developed into a real product that people could use in a factory or as a consumer product that ordinary people buy (i.e. palm oil produced by Chlamydomonas reinhardtii), it could involve safety risks. Indeed, engineered C. reinhardtii could accidentally escape into the environment which would cause problems as it would be an uncontrolled release of a GMO. For this purpose, we needed to think of biosafety measures to prevent it from being able to grow outside of a controlled environment. In Chlamydomonas reinhardtii chloroplast genome, UGA is the only codon absent from protein-coding genes 2. Therefore, the UGA codon in C. reinhardtii could be used to encode a synthetic amino acid thanks to a modified tRNA and facilitate the biocontainment of our engineered microalga. Indeed, we could include an “inducible lethality” device in C. reinhardtii by integrating the UGA codon and a modified tRNA gene in its genome. Our microalga will be in a confined environment, like a bioreactor, containing the synthetic amino acid. In this condition, the translation would occur normally (Figure 1). But if our modified C. reinhardtii accidentally escapes into the natural environment which does not contain the synthetic amino acid, the alga would die because the translation could not occur (Figure 1). Furthermore, if our modified microalga transfers its synthetic DNA to another organism, the UGA codon will be read by the ribosome as a stop codon and leading to the translation of a truncated protein.




SAFE LAB WORK

During the iGEM competition, all experiments were conducted in laboratories of Sorbonne University and CNRS under the surveillance of researchers (Assistant professor or PhD student) who are very familiar with the experimental procedures and practices we were using. Therefore, they showed us every safety and security measures prior to bench work. First of all, we always wore lab coat and appropriate clothing (long pants, closed shoes and hair tied back) in the lab. Then, although all components used in our experiments are classified as safe, we always wore protective gloves to prevent contamination of our samples. Indeed, in the EU, the CLP regulation (classification, labelling and packaging of substances and mixtures) or the Regulation N. 1272/2008 3 informs users about the risks of hazardous chemicals through their labelling with standard symbols and the creation of safety data sheets in order to protect human health and environment. However, we used Ethidium Bromide during our experiments. It is an intercalating agent used as a fluorescent dye to visualize DNA in gel electrophoresis. According to the EU Regulation N. 1272/2008, Ethidium Bromide is acute toxic, irritant and health hazard 4. Moreover, it is mutagen and probably carcinogen. For this purpose, we always worn protective gloves while handling this substance in a delimited area (Figure 2). We were careful to not touch and thereby contaminate other surfaces outside the area.




Then, after the experiments, we dropped the contaminated waste in specific bins and we always disinfected work areas and washed our hands with soap before leaving the lab. Finally, we can find in the laboratory common safety equipments like eye wash stations, showers, fire extinguishers and emergency cabinets that can be used in case of incident (Figure 3).




  1. Murbach, T., S., Glávits, R., Endres, J., R. A Toxical Evaluation of Chlamydomonas reinhardtii, a Green Algae. International Journal of Toxicology (2018), 37, 53-62.
  2. Young, R., E., B., Purton, S. Codon reassignment to facilitate genetic engineering and biocontainment in the chloroplast of Chlamydomonas reinhardtii. Plant Biotechnology Journal (2016), 14, 1251-1260.
  3. Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on classification, labelling and packaging of substances and mixtures, amending and repealing Directives 67/548/EEC and 1999/45/EC, and amending Regulation (EC) No 1907/2006 (Text with EEA relevance).
  4. Homodium Bromide : Safety and Hazards. PubChem. Available on pubchem.