Amino acid degradation by the mesophilic sulfate-reducing bacterium Desulfobacterium vacuolatum

La Trobe University Faculty of Science, Technology and Engineering Murray Darling Freshwater Research Centre

MDFRC item.

Desulfobacterium vacuolatum strain IbRM wasable to grow using casamino acids as a source of carbon,energy and nitrogen. Growth was accompanied by utilizationof several amino acids and sulfide production. Prolineand glutamate were used preferentially and to thegreatest extent. Glycine, serine and alanine were usedmore slowly and only after proline and glutamate wereused. Isoleucine, valine, leucine and aspartate decreasewas slowest and occurred in a linear fashion throughoutthe growth phase. Amino acids used from casamino acids,excluding aspartate, were also used as single carbon, energyand nitrogen sources. As a single amino acid, aspartatecould only be used as a nitrogen source. Aspartatewas not used as an electron acceptor. No growth occurredon any amino acid in the absence of sulfate. As singlesubstrates, isoleucine, proline and glutamate were oxidizedwithout formation of acetate and with molar yieldsof 13.1, 9.4 and 7.7 g mol–1, respectively.