The cellular fatty acids of the sulphate-reducing bacteria, Desulfobacter sp., Desulfobulbus sp. and Desulfovibrio desulfuricans

Abstract

The fatty acid profiles of Desulfobacter sp. grown on acetate and Desulfobulbus sp. grown on propionate, lactate and H2/CO2 were analysed. Desulfobacter sp. grown on acetate and Desulfobulbus sp. grown on H2/CO2 gave mainly even numbered straight chain acids but odd numbered acids predominated in Desulfobulbus sp. grown on propionate, reflecting the use of the growth substrates provided as chain initiators for fatty acid biosynthesis. The cellular fatty acids of Desulfobulbus sp. grown on lactate were distributed approximately evenly between even and odd straight chain acids. In contrast those of Desulfovibrio desulfuricans, were dominated by branched chain iso and anteiso fatty acids, when grown on either lactate or H2/CO2. On the basis of the fatty acid biosynthetic pathways these sulphate-reducing bacteria could be separated into two groups, one comprising Desulfobacter sp. and Desulfobulbus sp. and the other more primitive Desulfovibrio desulfuricans.