As our General Biological Engineering Special Prize our team wanted to choose the New Composite
Part. The decision was driven upon our team’s urge to have an impact on the world around us in
addition to having an impact on the synbio community. Our project MercuLess has a heavy emphasis on
With whole constructs that can be utilized in real-life applications as
they are, our team can have a practical impact to answer the United Nations’
Sustainable Development Goals.
In the creation of MercuLess, our team created a new composite part using Synechocystis as a host organism to make a sustainable way of methylmercury
bioremediation (Figure 1).
We designed a composition of many new parts for the iGEM community. In all our constructs we built on a pDF backbone. As our host organism does not yet have in silico tools to optimize the Ribosomal Binding Sites (RBS) for efficient protein translation, we used different combinations of RBSs ( RBS S3, RBS S4 and RBS S5) in our composite parts to find the most optimal one (Thiel et al., 2018).
The first RBS of the construct was followed by our gene of interest – merA. One of our genes was a native Synechocystis gene and the other was a homolog from Pseudomonas Aeruginosa. In some composite parts the merA gene was replaced by a reporter gene sYFP2. This allowed us to experiment with our genes of interest individually and also gain some important data of translation efficacy.
To start the translation of our other gene of interest, merB, a second RBS was needed to the composite. These RBS were the same as the previous ones, except they had different restriction sites. Because merB is not a native gene for Synechocystis, the homologs are either from Escherichia coli or Pseudomonas Aeruginosa. The merB homolog was followed by a transcription terminator sequence. Just like for merA, we also designed composite parts where the merB gene was replaced by a reporter gene EFE (Ethylene forming enzyme).