title: Analyses of the acetate-producing pathways in Corynebacterium glutamicum under oxygen-deprived conditions.
abstract: Corynebacterium glutamicum R efficiently produces valuable chemicals from glucose under oxygen-deprived conditions. In an effort to reduce acetate as a byproduct, acetate productivity of several mutant-disrupted genes encoding possible key enzymes for acetate formation was determined. Disruption of the aceE gene that encodes the E1 enzyme of the pyruvate dehydrogenase complex resulted in almost complete elimination of acetate formation under oxygen-deprived conditions, implying that acetate synthesis under these conditions was essentially via acetyl-coenzyme A (CoA). Simultaneous disruption of pta, encoding phosphotransacetylase, and ack, encoding acetate kinase, resulted in no measurable change in acetate productivity. A mutant strain with disruptions in pta, ack and as-yet uncharacterized gene (cgR2472) exhibited 65% reduced acetate productivity compared to the parental strain, although a single disruption of cgR2472 exhibited no effect on acetate productivity. The gene cgR2472 was shown to encode a CoA-transferase (CTF) that catalyzes the formation of acetate from acetyl-CoA. These results indicate that PTA-ACK as well as CTF is involved in acetate production in C. glutamicum. This study provided basic information to reduce acetate production under oxygen-deprived conditions.
authors.affiliation: Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto, 619-0292, Japan.
authors.forename: Kaori
authors.initials: K
authors.lastname: Yasuda
authors.forename: Toru
authors.initials: T
authors.lastname: Jojima
authors.forename: Masako
authors.initials: M
authors.lastname: Suda
authors.forename: Shohei
authors.initials: S
authors.lastname: Okino
authors.forename: Masayuki
authors.initials: M
authors.lastname: Inui
authors.forename: Hideaki
authors.initials: H
authors.lastname: Yukawa
mesh_terms: D000084:Acetate Kinase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D000085:Acetates / Q000378:metabolism*; D000693:Anaerobiosis; D015256:Coenzyme A-Transferases / Q000378:metabolism; D048230:Corynebacterium glutamicum / Q000201:enzymology* / Q000235:genetics* / Q000254:growth & development; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D010100:Oxygen / Q000378:metabolism; D010709:Phosphate Acetyltransferase / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism
chemical_list: D000085:Acetates; D010709:Phosphate Acetyltransferase; D000084:Acetate Kinase; D015256:Coenzyme A-Transferases; D010100:Oxygen