2,3-Butanediol Metabolism in the Acetogen Acetobacterium woodii

• Published in: Applied and Environmental Microbiology Vol. 81; no. 14; pp. 4711 - 4719
• Main Authors: Hess, Verena, Oyrik, Olga, Trifunović, Dragan, Müller, Volker
• Format: Journal Article
• Language: English
• Published: United States American Society for Microbiology 01.07.2015
• Subjects: Acetaldehyde - metabolism; Acetates - metabolism; Acetobacterium - enzymology; Acetobacterium - genetics; Acetobacterium - growth & development; Acetobacterium - metabolism; Acetobacterium woodii; Acetoin - metabolism; Bacterial Proteins - genetics; Bacterial Proteins - metabolism; Biochemistry; Biodegradation; Butylene Glycols - metabolism; Carbon Dioxide - metabolism; Enzymes; Gram-positive bacteria; Metabolism; Metabolites; Physiology
• ISSN: 0099-2240; 1098-5336; 1098-6596
• DOI: 10.1128/AEM.00960-15

The acetogenic bacterium Acetobacterium woodii is able to reduce CO2 to acetate via the Wood-Ljungdahl pathway. Only recently we demonstrated that degradation of 1,2-propanediol by A. woodii was not dependent on acetogenesis, but that it is disproportionated to propanol and propionate. Here, we analyzed the metabolism of A. woodii on another diol, 2,3-butanediol. Experiments with growing and resting cells, metabolite analysis and enzymatic measurements revealed that 2,3-butanediol is oxidized in an NAD(+)-dependent manner to acetate via the intermediates acetoin, acetaldehyde, and acetyl coenzyme A. Ethanol was not detected as an end product, either in growing cultures or in cell suspensions. Apparently, all reducing equivalents originating from the oxidation of 2,3-butanediol were funneled into the Wood-Ljungdahl pathway to reduce CO2 to another acetate. Thus, the metabolism of 2,3-butanediol requires the Wood-Ljungdahl pathway.