Team:LaVerne-Leos/Project
Currently, cyanobacteria is used to produce biofuel, however the process is too costly and inefficient to use on a large-scale production to replace fossil fuels. Many researchers have been successful increasing the amount of free fatty acids produced within the cells, which serve as the precursors to biofuel. However, scientists constantly run into a problem: high amounts of free fatty acids are toxic to the cell and kill it. Our aim is to reengineer cyanobacteria to increase the efficiency of biofuel production by improving the yield of fatty acids produced within each cell while solving the toxicity problem. To aid the cells in surviving these high amounts of toxicity we plan to upregulate the cells' carotenoids, which will stabilize their membranes and get rid of reactive oxygen species. With a stronger, more stable cell membrane, the cyanobacteria should be able to produce more free fatty acids, thus producing more biofuel, making it a step closer to the solution of a renewable energy source.
Carotenoid pigments are naturally occurring within photosynthetic organisms, and protect the cell against high amounts of light exposure. Specifically, Zeaxanthin, is one of the carotenoids that can be synthesized within cells. Some bacteria, such as Staphlycoccus Aureus, are able to live in the fatty acids located on our skin (citation). The mechanism in which these bacteria are able to thrive is by up regulating genes related to cell wall thickness, and membrane bound carotenoid concentrations. By using this same mechanism we hope to help the cyanobacteria cope with the fatty acids that they themselves have been genetically modified to make.
The amount of tocopherols within a cell is proportional to the amount of fatty acids produced, which indicates that the more fatty acids produced, the more tocopherols are produced. Due to this dynamic relationship, making a large amount of tocopherols requires an increase of the rate limiting enzyme homogentisic acid.
References
Desbois, A. P., & Smith, V. J. (2010). Antibacterial free fatty acids: activities, mechanisms of action and biotechnological potential. Applied Microbiology & Biotechnology, 85(6), 1629–1642. http://doi.org/10.1007/s00253-009-2355-3
Ruffing, A. M., & Jones, H. D. T. (2012). Physiological Effects of Free Fatty Acid Production in Genetically Engineered Synechococcus elongatus PCC 7942. Biotechnology and Bioengineering, 109(9), 2190–2199. http://doi.org/10.1002/bit.24509
Stahl, W., & Sies, H. (2003). Antioxidant activity of carotenoids. Molecular Aspects of Medicine, 24(6), 345–351. http://doi.org/10.1016/S0098-2997(03)00030-X
About Us
We are the first iGEM team from University of La Verne and La Canada High School. We are an interdisciplinary team with members from biology, math, computer science, art, and library science. We are a community-engaged team that hopes to partner with other high schools, non-profits, and local businesses to create innovative solutions to global issues!
Contact info
Natural Science Division Office and Biology Department
1950 3rd St. La Verne, CA 91750
Email: ulvigemteam@gmail.com