Engineering Saccharomyces cerevisiae for Efficient Biosynthesis of Fatty Alcohols Based on Enhanced Supplyof Free Fatty Acids

摘要

In recent years, production of fatty acid derivatives has attracted much attention because of their wide range of applications in renewable oleochemicals. Microorganisms such as Saccharomyces cerevisiae provided an ideal cell factory for such chemical synthesis. In this study, an efficient strategy for the synthesis of fatty alcohols based on enhanced supply of free fatty acids (FFAs) was constructed. The FAA1 and FAA4 genes encoding two acyl-CoA synthetases in S. cerevisiae were deleted, resulting in the accumulation of FFAs with carbon chain length from C8 to C18. The coexpression of the carboxylic acid reductase gene (car) from Mycobacterium marinum and the phosphopantetheinyl transferase gene (sfp) from Bacillus subtilis successfully converted the accumulated FFAs into fatty alcohols. The concentration of the total fatty alcohols reached 24.3 mg/L, which is in agreement with that of the accumulated FFAs. To further increase the supply of FFAs, the DGAI encoding the acyl-CoA:diacylglycerol acyltransferase involved in the rate-limiting step of triacylglycerols storage was codeleted with FAA1 and FAA4, and the acyl-CoA thioesterase gene (acot) wasexpressed together with car and sfp, resulting in an enhanced production of fatty alcohols, the contentof which increased to 31.2 mg/L. The results herein demonstrated theefficiency of the engineered pathway for the production of fatty acidderivatives using FFAs as precursors.