Study of the Potential of Reversal of the Fatty Acid Beta-Oxidation Pathway for Stereoselective Biosynthesis of (S)-1,3-Butanediol from Glucose by Recombinant Escherichia coli Strains

Abstract

A possible contribution of collateral enzymes to the formation of key precursor metabolite, 3-hydroxybutyryl-CoA, in a recombinant Escherichia coli strain engineered for 1,3-butanediol biosynthesis from glucose through the inverted fatty acid beta-oxidation pathway has been evaluated. The inactivation of the 3-hydroxyadipyl-CoA dehydrogenase gene, paaH, did not prevent the 1,3-butanol biosynthesis during anaerobic glucose utilization by the strain with the intact essential gene fabG coding for 3-ketoacyl-ACP reductase, which can catalyze the conversion of acetoacetyl-CoA to (R)-3-hydroxybutyryl-CoA. The subsequent inactivation in the strain of fadB gene coding for (S)-stereospecific 3-hydroxyacyl-CoA dehydrogenase of the fatty acid beta-oxidation led to the abolishment of the 1,3-butanediol synthesis. The respective diol was also not found among the products secreted by the strain possessing the intact fabG and paaH genes upon an individual deletion of fadB gene. It was established that the collateral enzymes did not participate in the formation of 3-hydroxybutyryl-CoA in the studied strains and the respective CoA-derivative was synthesized solely by the (S)-specific enzyme of the fatty acid beta-oxidation pathway. The obtained results indicate that the reversal of the fatty acid beta-oxidation pathway can ensure the enantioselective biosynthesis of the (S)-stereoisomer of 1,3-butanediol in engineered E. coli strains. 1,3-butanediol, fatty acid beta-oxidation, Escherichia coli, glucose, metabolic engineering, stereoisomer. The work was carried out with financial support Russian Foundation for Fundamental Research (No. 18-29-08059).