초록
<P><B>Abstract</B><P><I>Desulfofundulus kuznetsovii</I> is a thermophilic, spore-forming sulphate-reducing bacterium in the family <I>Peptococcaceae</I>. In this study, we describe a newly isolated strain of <I>D. kuznetsovii</I>, strain TPOSR, and compare its metabolism to the type strain <I>D. kuznetsovii</I> 17<SUP>T</SUP>. Both strains grow on a large variety of alcohols, such as methanol, ethanol and propane-diols, coupled to the reduction of sulphate. Strain 17<SUP>T</SUP> metabolizes methanol via two routes, one involving a cobalt-dependent methyl transferase and the other using a cobalt-independent alcohol dehydrogenase. However, strain TPOSR, which shares 97% average nucleotide identity with <I>D. kuznetsovii</I> strain 17<SUP>T</SUP>, lacks several genes from the methyl transferase operon found in strain 17<SUP>T</SUP>. The gene encoding the catalytically active methyl transferase subunit B is missing, indicating that strain TPOSR utilizes the alcohol dehydrogenase pathway exclusively. Both strains grew with methanol during cobalt starvation, but growth was impaired. Strain 17<SUP>T</SUP> was more sensitive to cobalt deficiency, due to the repression of its methyl transferase system. Our findings shed light on the metabolic diversity of <I>D. kuznetsovii</I> and their metabolic differences of encoding one or two routes for the conversion of methanol.</P></P>