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Please visit the main Safety page to find this year's safety requirements & deadlines, and to learn about safe & responsible research in iGEM.
Safe Project Design
Sophorolipids are a series of amphipathic glycolipid compounds synthesized by yeasts such as Starmerella bombicola. These compounds are among the most industrially viable biosurfactants. As surfactants, sophorolipids are superior to current synthetic alternatives largely due to their low toxicity and ready biodegradability. In addition, medium-chain length sophorolipids have shown promise in anti-cell proliferation and anti-microbial assays. However their higher cost of production, largely as a result of the difficulty of isolating and refining useful sophorolipids, stands as a major barrier to commercial use. The variety of fatty acid chain lengths is another shortcoming that restricts therapeutic applications at present, as a heterogeneous mixture is not as dependable as a set of pure, isolated compounds. Even when grown on a substrate largely composed of fatty acids, a significant portion of these are diverted away from sophorolipid production through competition with the β-oxidation pathway. Fatty acids diverted into the β-oxidation pathway undergo semi-random cleavage, lowering sophorolipid yield and creating a mixture of products. Full suppression of this pathway is undesirable given it is a critical metabolic pathway for the yeast. Selective suppression of various active domains of the enzyme MFE-2 through genetic engineering has the potential to select for only useful chain lengths, reducing the cost of production.
No safety or ethical risks are involved with using sophorolipids as an alternative to industrial surfactants. In fact, sophorolipids are a more environmentally friendly option than their synthetic surfactant counterparts, due mainly to their low toxicity and ready biodegradability. Since the anti-cancer properties of medium chain length sophorolipids have not been thoroughly tested, using sophorolipids as an anti-cancer therapy would present a potential safety risk at this time. Extensive testing and clinical trials would be required before using sophorolipids for this purpose. Our project concerns the manufacture of sophorolipids in yeast, their purification, and their performance in assays. Our project will not include testing sophorolipids on animal or human subjects, and our project will not include releasing sophorolipids into the environment.