Production of adipic acid by short- and long-chain fatty acid acyl-CoA oxidase engineered in yeast Candida tropicalis

Abstract

In this study, to produce adipic acid, mutant strains of Candida tropicalis KCTC 7212 deficient of AOX genes encoding acyl-CoA oxidases which are important in the β-oxidation pathway were constructed. Production of adipic acid in the mutants from the most favorable substrate C12 methyl laurate was significantly increased. The highest level of production of adipic acid was obtained in the C. tropicalis ΔAOX4::AOX5 mutant of 339.8 mg L-1 which was about 5.4-fold higher level compared to the parent strain. The C. tropicalis ΔAOX4::AOX5 mutant was subjected to fed-batch fermentation at optimized conditions of agitation rate of 1000 rpm, pH 5.0 and methyl laurate of 3% (w/v), giving the maximum level of adipic acid of 12.1 g L-1 and production rate of 0.1 g L-1 h-1.