Fermentative production of 1-propanol from d-glucose, l-rhamnose and glycerol using recombinant Escherichia coli

Abstract

Fermentative production of 1-propanol, which is one of the promising precursors of polypropylene production, from d-glucose, l-rhamnose and glycerol using metabolically engineered Escherichia coli was examined. To confer the ability to produce 1-propanol from 1,2-propanediol (1,2-PD) in recombinant E.coli, a part of the pdu regulon including the diol dehydratase and the propanol dehydrogenase genes together with the adenosylcobalamin (AdoCbl) regeneration enzyme genes of Klebsiella pneumoniae was cloned, and an expression vector for these genes (pRSF_pduCDEGHOQS) was constructed. Recombinant E.coli harboring pRSF_pduCDEGHOQS with 1,2-PD synthetic pathway (pKK_mde) genes, which was constructed in our previous report (Urano etal., Appl. Microbiol. Biotechnol., 99, 2001-2008, 2015), produced 16.1mM of 1-propanol from d-glucose with a molar yield of 0.36mol/mol after 72h cultivation. 29.9mM of 1-propanol was formed from l-rhamnose with a molar yield of 0.81mol/mol using E.coli carrying only pRSF_pduCDEGHOQS. In addition, 1-propanol production from glycerol was achieved by addition of the ATP-dependent dihydroxyacetone kinase gene to E.coli harboring pKK_mde and pRSF_pduCDEGOQS. In all cases, 1-propanol production was achieved by adding only a small amount of AdoCbl.