Description of Fabibacter halotolerans gen. nov., sp. nov. and Roseivirga spongicola sp. nov., and reclassification of [Marinicola] seohaensis as Roseivirga seohaensis comb. nov.

Bacterial strains UST030701-097T and UST030701-084T were isolated from a marine sponge in the Bahamas. Both strains were pink-pigmented, Gram-negative, strictly aerobic and chemo-organotrophic. Cells of strain UST030701-097T were short, curved rods with fast-gliding motility, whereas those of strain UST030701-084T were straight rods with a less rapid gliding motion. The two strains had MK-7 as the major respiratory quinone and did not produce flexirubin-type pigments. The DNA G+C contents of strains UST030701-097T and UST030701-084T were 42.5 and 43.7 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the two strains belonged to the family 'Flexibacteraceae' of the phylum Bacteroidetes. 16S rRNA gene sequence similarity between strains UST030701-097T and UST030701-084T was 95.0 %; their closest relative was [Marinicola] seohaensis, with 93.3 % and 96.0 % sequence similarity, respectively. Phylogenetic tree topology indicated that the two strains belonged to the same lineage, but were on separate branches. Whilst strain UST030701-084T and [Marinicola] seohaensis were found on one branch, strain UST030701-097T was in another branch that had no species with validly published names. Based on the polyphasic taxonomic data obtained in the present study, we propose that strain UST030701-097T represents a novel genus and that strain UST030701-084T represents a novel species in the phylum Bacteroidetes. The genus Fabibacter gen. nov. is proposed, with strain UST030701-097T (=NRRL B-41220T=JCM 13334T) as the type strain of the type species, Fabibacter halotolerans sp. nov. Strain UST030701-084T (=NRRL B-41219T=JCM 13337T) is proposed as the type strain of Roseivirga spongicola sp. nov. In an earlier study, it was suggested that the genus Marinicola is a later heterotypic synonym of the genus Roseivirga. However, a formal proposal to reclassify [Marinicola] seohaensis, the only member of the genus Marinicola, has not yet been made. The results of phylogenetic analyses in this study support the reclassification of [Marinicola] seohaensis as Roseivirga seohaensis comb. nov.

Stenothermobacter spongiae gen. nov., sp. nov., a novel member of the family Flavobacteriaceae isolated from a marine sponge in the Bahamas, and emended description of Nonlabens tegetincola.

A bacterial strain, UST030701-156T, was isolated from a marine sponge in the Bahamas. Strain UST030701-156T was orange-pigmented, Gram-negative, rod-shaped with tapered ends, slowly motile by gliding and strictly aerobic. The predominant fatty acids were a15 : 0, i15 : 0, i15 : 0 3-OH, i17 : 0 3-OH, i17 : 1omega9c and summed feature 3, comprising i15 : 0 2-OH and/or 16 : 1omega7c. MK-6 was the only respiratory quinone. Flexirubin-type pigments were not produced. Phylogenetic analysis based on 16S rRNA gene sequences placed UST030701-156T within a distinct lineage in the family Flavobacteriaceae, with 93.3 % sequence similarity to the nearest neighbour, Nonlabens tegetincola. The DNA G+C content of UST030701-156T was 41.0 mol% and was much higher than that of N. tegetincola (33.6 mol%). Strain UST030701-156T can be distinguished from other members of the Flavobacteriaceae by means of a number of chemotaxonomic and phenotypic characteristics. It is proposed, therefore, that UST030701-156T represents a novel taxon designated Stenothermobacter spongiae gen. nov., sp. nov. The type strain is UST030701-156T (= NRRL B-41138T = JCM 13191T). Carbon-source utilization by N. tegetincola was re-examined and an emended description is therefore included.

Winogradskyella poriferorum sp. nov., a novel member of the family Flavobacteriaceae isolated from a sponge in the Bahamas.

A Gram-negative, rod-shaped bacterium (designated strain UST030701-295(T)) with fast gliding motility was isolated from the surface of the sponge Lissodendoryx isodictyalis in the Bahamas. Colonies of UST030701-295(T) were yellow in colour, 2-4 mm in diameter, convex with a smooth surface and entire margins. UST030701-295(T) was heterotrophic, strictly aerobic and required NaCl for growth (1.0-4.0%). Growth was observed at pH 6.0-10.0 and at 12-44 degrees C. Phylogenetic analysis of the 16S rRNA gene sequence placed UST030701-295(T) within the genus Winogradskyella of the family Flavobacteriaceae, sharing 94.7-95.8% similarity with the three recognized members of the genus. The G+C content of the DNA was 32.8 mol% and the predominant fatty acids were iso-C(15:1), iso-C(15:0), iso-C(15:0) 2-OH, iso-C(15:0) 3-OH, iso-C(16:0) 3-OH, C(16:1)omega7 and iso-C(17:0) 3-OH (together representing 75.4% of the total); these data supported the affiliation of UST030701-295(T) to the genus Winogradskyella. UST030701-295(T) differed from the three recognized species of Winogradskyella in 7-17 traits. Molecular evidence together with phenotypic characteristics suggests that UST030701-295(T) represents a novel species within the genus Winogradskyella, for which the name Winogradskyella poriferorum sp. nov. is proposed. The type strain is UST030701-295(T) (=NRRL B-41101(T)=JCM 12885(T)).