Nature of Butyrate Oxidation by Mycoplasma Hominis.

VanDemark, P. J. (Cornell University, Ithaca, N.Y.), and P. F. Smith. Nature of butyrate oxidation by Mycoplasma hominis. J. Bacteriol. 89:373-377. 1965.-Cell-free extracts of butyrate - grown Mycoplasma hominis strain O7, though lacking thiokinase activity on butyric acid, were found to activate butyrate via an acetyl-butyric thiophorase. These extracts also contained an aceto-coenzyme A (CoA) kinase, a butyryl-CoA dehydrogenase, a crotonase, a reduced nicotinamide adenine dinucleotide-specific beta-hydroxybutyryl-CoA dehydrogenase, and a thiolase. Thiolase activity was stimulated by the addition of magnesium ions. The presence of these enzyme activities in this Mycoplasma species supports the hypothesis that a fatty acid oxidation represents an energy source for the nonfermentative pleuropneumonia-like organisms.