Catnip synthesis

Team GreatBay_China won the finalist award in IGEM competition this October in the high school division. This was exciting news since they were the only Chinese high school team that had ever triumphed with a grand prize. GreatBay, initiated by Bluepha Lab in the Shenzhen, gathered members from all across China. GreatBay presented a unique science project that connected two seemingly unrelated subjects: cats and biosynthesis. This interesting approach was all centered around catnip, a plant that has a natural calming effect for cats. A key component in catnip is nepetalectone, which would arouse sexual-related behaviors to felines, and thus soothing them.

GreatBay synthesized nepetalectol, the precursor to nepetalectone, since it could be an intermediate in the pathway to MIAs, a family of metabolites valuable for medical use. Although there were already existing studies synthesizing MIAs, their methods were costly and and inefficient. GreatBay, as a result, aimed to manufacture nepetelactol more effectively, so that expensive MIAs, the yield of the chain, could more affordable.

The team made a smart move by dividing the synthesis process into two steps: first feed the E.Coli with a carbon source to generate geranoil, one of the simpler precursors in the chain of reactions, and then employ S. cerevsiae, or yeast, to further transfer geranoil into nepetalectol. This idea sounded fantastic, for E. Coli does an efficient job producing relatively simple products while S. cerevisae manufactures complicated molecules. However, GreatBay had to face much more obstacles ahead. Their challenge was to genetically modify the synthesis pathways in those cell factories and create a co-cooperative system among E. Coli and yeast.

E.Coli and yeast were not endowed with the capabilities of transforming geranoil and nepetalectol respectively, so the talented young scientists came up with ways to knock out certain gene sequences formulate the suitable bio-circuits for each one. Then they faced another problem: the two organisms inhibit each the growth of each other due to their duplication time and metabolized waste. They figured the solution by developing a model to initiate the number of bio-factories in a certain ratio, and replaced their original carbon source, glucose, with xylose to further maintain a stable consortium. With all of these efforts, GreatBay was able to synthesize nepelectol at a steady rate.

GreatBay not only focused on biosynthesizing but also inaugurated their human practices by saving cats. They designed Kitty Wonderlands or small wooden houses that contained synthesized catnip, for stray cats. The team also filmed documentaries and to increase public attention about pet-saving. GreatBay was a strong team that worked in a well-rounded way, from biosynthesizing in labs to applying their products in real life.