Great things are not done by impulse, but by a series of small things brought together. – Vincent van Gogh

This year we expanded the Marburg Collection from 2018 with 55 new parts to the Marburg Collection 2.0. With our developed workflow we could characterize our parts and compare them with a second measurement method: FACs. We added two new features for genome engineering of cyanobacteria: a CRISPR/cpf1 guided knockout system as well as a modularized assembly of repair templates for the knock in of genes (M.E.G.A. expansion). This includes integration sites that target conventional neutral sites in cyanobacteria but we also rationally designed two novel integration sites based on RNA-seq data. Additionally we offer the first MoClo compatible shuttle vector for cyanobacteria and characterized gene expression based on that origin of replication. We used our new shuttle vector to build standardized devices for the characterization of BioBricks in cyanobacterial chassis to improve the reproducibility of results and to simplify large scale assemblies. For this we used placeholders, a novel part type that aids in the construction of a larger set of parts by reducing the involved cost and workload significantly. Additionally we tested our toolbox with PCC 7942 to show that the Marburg Collection 2.0 is also working with similar cyanobacterias. We offer free access to the data of our characterization, enabling the iGEM community and scientists to choose the parts based on this data. To improve the measurement method applicable for cyanobacteria we focused on measurements via luminescence reporters over fluorescence reporters, because of the fact that cyanobacteria emmit autofluorescence. This way our results are way more accurate, because of the reduced background noise. The higher accuracy is obviously visible during the measurement of our parts, where we could see a difference of 5x10^5 between the background noise and the signal, which implements that already a small amount of sample has a more intensive signal.

Hereby, we want to encourage the community of young scientists to work with the fastest phototrophic organism Synechococcus elongatus UTEX 2973 because of its high relevance for biotechnological applications.