Kinetics and distribution of alcohol oxidising activity in Acholeplasma and Mycoplasma species

Alcohol metabolism by Acholeplasma and Mycoplasma cell suspensions was dete rmined using changes in dissolved oxygen tension to monitor oxygen uptake. All seven Acholeplasma test species oxidised ethanol and (where tested) pro panol, butanol and pentanol. The rate of oxidation. at any particular subst rate concentration, decreased with increasing alcohol molecular mass. Among st 20 Mycoplasma species tested. M. agalactiae, M bovis, M. dispar, M. gall isepticum, M. pneumoniae and M. ovipneumoniae oxidised ethanol. Propanol wa s also oxidised by M. dispar and isopropanol by M. agalactiae, M. bovis and M. ovipneumoniae. Isopropanol was oxidised at particularly high rates (V-m ax > 100 nmol O-2 taken up min(-1) mg cell protein(-1)) and with a relative ly high affinity (K-m value < 2 mM); oxygen uptake was consistent with oxid ation to acetone. The significance of alcohol oxidation is unclear, as it w ould not be predicted to lead to ATP synthesis. (C) 2000 Federation of Euro pean Microbiological Societies. Published by Elsevier Science B.V. All righ ts reserved.