A taxonomic study was carried out on strain P24 T , which was isolated from a polycyclic aromatic hydrocarbon-degrading consortium, enriched from a deep-seawater sample collected from the Indian Ocean. The isolate was Gram-negative, rod-shaped, motile by means of a polar flagellum, moderately halophilic and capable of reducing nitrate to nitrite. Growth was observed at salinities of 0-9 % and at temperatures of 10-42 6C. The strain was unable to degrade Tween 80 or gelatin. The dominant fatty

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... ids were C 16 : 0 (15.2 % of the total), C 18 : 0 (10.3 %), C 18 : 1 v7c (52.0 %), C 18 : 1 2-OH (4.7 %) and C 19 : 0 v8c cyclo (4.7 %). The G+C content of the chromosomal DNA was 64.8 mol%. 16S rRNA gene sequence comparisons showed that strain P24 T was related most closely to Thalassobaculum litoreum CL-GR58 T (92.7 % similarity); levels of similarity between strain P24 T and type strains of recognized species in the family Rhodospirillaceae were all less than 90.8 %. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain P24 T formed a distinct evolutionary lineage within the family Rhodospirillaceae. Strain P24 T could be distinguished from phylogenetically related genera based on differences in several phenotypic properties. On the basis of the phenotypic and phylogenetic data presented, strain P24 T is considered to represent a novel species of a new genus, for which the name Oceanibaculum indicum gen. nov., sp. nov. is proposed. The type strain is P24 T (5CCTCC AB 208226 T 5LMG 24626 T 5MCCC 1A02083 T ). Genomic DNA was prepared according to the method of Ausubel et al. (1995) ; the 16S rRNA gene was amplified by Abbreviation: PAH, polycyclic aromatic hydrocarbon. The GenBank/EMBL/DDBJ accession number for the 16S rRNA gene sequence of strain P24 T is EU656113. Transmission electron micrographs of negatively stained cells of strain P24 T and a table giving the cellular fatty acid contents of strain P24 T and related genera are available as supplementary material with the online version of this paper.