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From 2013.igem.org

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Project Description

Lactobacillus is one of the major groups of bacteria used in yogurt production. Our iGEM project explores the ways in which we could engineer Lactobacillus to improve yogurt. First, we are examining the problem of viral infections, which can cause batches of yogurt to fail. Considerable efforts, including sterilization strategies and culture rotation schedules, are used to reduce plant downtime caused by these phages. By incorporating CRISP-R bacterial immunity into Lactobacillus, specifically targeting it to prevent infection from common dairy phages, we are attempting to “vaccinate” yogurt fermenters against viral collapse.

Second, we are trying to avoid the cost of adding flavour to yogurt after fermentation by engineering the bacteria to produce these compounds themselves. This would also lessen our reliance on food additives derived from petrochemicals, thereby making fermented dairy products greener. We plan on engineering metabolic pathways which will flavour our yogurt with vanilla and cinnamon by producing vanillin and cinnamaldehyde, respectively. We are also working to construct a caffeine synthesis pathway to see if food products can be “naturally” caffeinated by bacteria. We are currently implementing the CRISP-R immune system and flavour production pathways in E. coli as a proof of concept.

Finally, as dairy probiotics are widely accepted as not only being safe, but beneficial, they provide an interesting system to explore the controversial issue of genetically modified organisms in food. We’re working with locals from business, marketing, philosophy, psychology and land and food systems to see if we can better understand how a variety of people approach the issue.