Metabolic engineering for enhanced biofuel precursors production in saccharomyces cerevisiae
Date of Issue2015
School of Chemical and Biomedical Engineering
The fatty acids are important precursors for the production of valuable chemicals and fuels. In this study, the Saccharomyces cerevisiae was designed for the enhanced production of fatty acids and fatty acids derivatives. The idh1 and idh2 genes involved in citrate turnover pathway in the TCA cycle were knocked out to accumulate intracellular citrate. A heterologous ATP-citrate lyase was cloned and overexpressed into the idh1/2 gene disrupted strain, to convert the accumulated citrate to acetyl-CoA for fatty acid synthesis. To convert the fatty acids to the fatty acid derivatives, the dga1 gene responsible for the rate limiting step of fatty acyl-CoA dependent pathway of TAGs synthesis was deleted, to release more fatty acyl-CoAs from TAGs. The fatty acyl-CoA reductase gene was cloned and overexpressed in the dga1 gene disrupted strain, to convert the accumulated fatty acyl-CoAs to fatty alcohols. The metabolic engineered pathway not only increased the fatty acids production levels in the Saccharomyces cerevisiae, but also successfully solved the bottleneck of utilizing TAGs as precursors for the production of fatty acid derivatives.