Team:UMaryland/Description
Project Description
Lutein is a dietary supplement used as both a treatment and preventative measure for Age-Related Macular Degeneration. Our primary research focus is to combat AMD through lutein production. Lutein is currently extracted from the petals of marigolds, but we hope to create a more cost-effective and efficient way of synthesizing this carotenoid via bacterial pathways. Our goal is to optimize the production of lutein through the careful manipulation of promoters for various enzymes, not native to E. Coli, in the lutein pathway. This pathway begins with lycopene, which is then converted to alpha-carotene with the addition of epsilon- and then beta-cyclase. Alpha-carotene is then converted to lutein through epsilon- and beta-hydroxylase. In order to ensure that we are producing alpha carotene instead of beta carotene, we will be manipulating the regulation of epsilon and beta cyclase by testing various promoter pairings. We will then use this data to help model the synthetic pathway and hopefully create a user friendly tool to help iGEM teams in the future model synthetic projects.
We are also working on testing alternative plasmid maintenance systems that would minimize or eliminate the need for repeated antibiotic exposure in the field. Currently, iGEM uses chloramphenicol as a negative selection pressure to maintain plasmids within cells. While chloramphenicol or another antibiotic may be used initially as a selective agent to identify proper transformants, toxin/antitoxin (TA) systems are capable of maintaining plasmids during growth, removing the need to constantly replenish antibiotics in the growth media. The Hok/Sok system is a toxin/antitoxin system that involves a quick degrading antitoxin (Sok) and a long-lasting toxin (Hok). Cells with the Hok/Sok plasmid will produce large amounts of quick-degrading anti-toxin to inhibit the toxin, while those that eject the plasmid would not be able to produce Sok, thereby leading to cell death as Hok would still be present within the bacterium.