Investigations of lipid metabolism in Yarrowia lipolytica

Abstract

An investigation of the lipid metabolism pathway in the yeast Yarrowia lipolytica was conducted. Yarrowia is an oleaginous ascomycete that is capable of growing on many different substrates, which derives its name from its high efficiency of growth on lipids. Once the exogenous lipids are converted into free fatty acids and internalized by the yeast, the primary mode of degradation is through β-oxidation mediated by the peroxisomal oxidases, or POX genes. These enzymes catalyze the formation of a trans double bond, producing the trans-2-enoyl product. Our study looked at the comparison of the Y. lipolytica prototrophic strain against a knockout of the Pox2 gene on the uptake, incorporation, and degradation of relevant fatty acids. To construct this gene knockout, a novel gene deletion method using a combination of Cre recombinase and the AHAS* gene was synthesized, developed, and tested successfully. This knockout system allows for serial deletion of genes with the use of only one resistance marker, with excision of the marker after selection.