Oxidation of primary aliphatic alcohols by Acetobacterium carbinolicum sp. nov. : a homoacetogenic anaerobe

Abstract

Four strains of new homoacetogenic bacteria were enriched and isolated from freshwater sediments and sludge with ethanol, propanol, 1,2-propanediol, or 1,2-butanediol as substrates. All strains were Gram-positive nonsporeforming rods and grew well in carbonate-buffered defined media under obligately anaerobic conditions. Optimal growth occurred at 27 ~ C around pH 7.0. H2/CO2, primary aliphatic alcohols C1- C5, glucose, fructose, lactate, pyruvate, ethylene glycol, 1,2-propanediol, 2,3-butanediol, acetoin, glycerol, and methyl groups ofmethoxylated benzoate derivates and betaine were fermented to acetate or, in case of primary alcohols C3-C5 and 1,2-propanediol, to acetate and the respective fatty acid. In coculture with methanogens methane was formed, probably due to interspecies hydrogen transfer. Strain WoPropl is described as a new species, Aeetobacterium carbinolicum. It had a DNA base composition of 38.5 _+ 1.0% guanine plus cytosine, and contained murein of crosslinkage type B similar to A. woodii.