Desulfosarcina widdelii sp. nov. and Desulfosarcina alkanivorans sp. nov., hydrocarbon-degrading sulfate-reducing bacteria isolated from marine sediment and emended description of the genus Desulfosarcina.

In previous studies, two hydrocarbon-degrading sulfate-reducing bacteria, strains PP31T and PL12T, were obtained from oil-polluted marine sediments of Shuaiba, Kuwait. They had been reported as organisms capable of anaerobic degradation of p-xylene and n-alkanes, respectively. The 16S rRNA gene sequence of strain PP31T showed 98.8 % sequence similarities to that of Desulfosarcina variabilis'Montpellier'T. Strains PL12T had 97.8 % of sequence similarity to Desulfosarcina ovata oXys1T. They both have been partially characterized, but not been validly published as new species of the genus Desulfosarcina. In this study, additional characterizations of these strains were made to describe them as two new species of the genus Desulfosarcina. Major cellular fatty acids of strain PP31T were C15 : 0 (25.9 %) and anteiso-C15 : 0 (22.3 %), whereas those of strain PL12T were C15 : 0 (21.3 %), C16 : 0 (17.8 %) and anteiso-15 : 0 (11.6 %). The phylogenetic tree based on 16S rRNA gene revealed that these isolates should not be classified as any of the known species in the genus Desulfosarcina. On the basis of phenotypic and phylogenetic analyses, these two sulfate reducers are proposed to form two novel species of the genus Desulfosarcina : Desulfosarcina widdelii sp. nov. (PP31T=JCM 31729T=DSM 103921T) and Desulfosarcina alkanivorans sp. nov. (PL12T=JCM 31728T=DSM 103901T). In addition, emended description of the genus Desulfosarcina is presented in this study.