Identification and Regulation of Genes Coding for Enzymes Involved in Algal Lipid Production

Triacylglycerols (TAG) are lipid structures that are produced in plants and algae to store energy for survival during conditions that are unfavorable for growth and reproduction. The chemical energies stored in these complexes can be harnessed and converted for use as biodiesel. We are ultimately interested in determining the conditions to optimize TAG production in two algal species Chlorella protothecoides and Schizochytrium. Since neither species has been sequenced, we first attempted to sequence 4 genes involved in TAG production in both species using degenerate PCR techniques, subcloning, and sequencing. Three of the genes are enzymes involved directly in TAG formation; pyruvate dehydrogenase, acetyl coenzyme A carboxylase, and diacylglycerol acyltransferase. The fourth gene is ADP‐glucose pyrophosphorylase small subunit, which is part of a regulation mechanism responsible for directing the synthesis of carbohydrates, which is a competitive process to TAG synthesis. The gene sequences that we were able to obtain were used in the development of a rapid detection assay using real‐time PCR to detect both increases and decreases in gene expression. We are currently testing the importance of these genes in lipid production, as well as how they are regulated, particularly in environments that should promote lipid production.