Comparative proteomics of Desulfotomaculum kuznetsovii grown on methanol and ethanol

The aim of this study was to unravel the methanol metabolism of Desulfotomaculum kuznetsovii. Anaerobic methylotrophs, such as methanogens and acetogens, use a pathway initiated by a cobalamine-containing methanol methyltransferase, whereas aerobic methylotrophs generally oxidize methanol to formaldehyde through a pathway initiated by a methanol dehydrogenase. Sulfate-respiring cells grown with methanol in the presence and absence of cobalt and vitamin B12 were analyzed and compared with cells grown with lactate or ethanol. Proteome analysis showed the presence of two methanol degrading pathways in D. kuznetsovii: a cobalt-dependent methanol methyltransferase and a cobalt-independent alcohol dehydrogenase. This is the first time that two methanol pathways have been shown to be present in a single microorganism, and we hypothesize this can give D. kuznetsovii a competitive advantage.