This year, Nanjing_NFLS used an existing Part of Ice Nucleation Protein inaK (BBA_K3146007) to construct our extracellular enzyme display system. The ice nucleation protein is used as an anchoring motif to immobilize the enzyme onto the bacterial outer membrane. This way, the enzyme can directly come into contact with the toxins in the environment and perform efficient degradation. (Liu et al., 2020)

Large quantities of microcystins can be produced during harmful algal blooms, threatening water quality. The contaminated water may enter the food chain via irrigation or directly harm people who drank it. In 1996, Microcystin-LR present in the water for hemodialysis treatment led to the death of over 60 patients in Caruaru, Brazil. (Jochimsen et al., 1998) This incident greatly helped gather attention on microcystin pollution issues and eventually led World Health Organization to include microcystin-LR in its Guidelines to Drinking Water Quality, with 1 µg/L as the provisional guide value.

We verified the design validity with restrictive endonuclease digestion, western blotting following cell fractionation, and HPLC degradation assays. All protocols and results were carefully documented in our wiki and the Registry. Environmental monitoring and bioremediation have always been popular iGEM topics, and we hope our contributions could be of some reference for future teams!

View our contribution in the Parts Registry!