Team:British Columbia/Project/PopulationControl


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Population Control

An example of an industrial process that is susceptible to phage-mediated collapse is the fermentative production of yogurt. With the amount of work that the iGEM community has put into the production of compounds such as vanillin and caffeine, we envision the next generation microbes in yogurt fermentation being able produce these products in vivo. Consolidating these, however, might not be efficient because while many people may want vanilla flavoured yogurt, there might only be a subset of those who want the caffeine boost. This got us thinking about engineering CRISPR in a way that allows population control in a bioreactor. For example, there could be a vanilla producing bacterial strain that is immune to all the known environmental phage while a caffeine producing strain is also immune, but selectively susceptible to a rare phage. In a co-culture fermentation, which is the situation in yogurt production, the system could be phage resistant but the targeted addition of a rare phage could knock down a subset of the population and effectively remove any caffeine producing bacteria from the fermentation. We worked on biosynthetic pathways such as those producing vanillin, cinnamaldehyde, and caffeine to further part characterization in addition to modelling and validating parts of our hypothetical system. A proof-of-concept experiment showing targeted population control using CRISPR in E. coli is underway and will be presented in Toronto. In the mean time, you can read about the work we have done on biosynthesis here: