Vallitalea sediminicola sp. nov. and Vallitalea maricola sp. nov., anaerobic bacteria isolated from deep-marine sediment.

Abstract

Two obligately anaerobic, Gram-stain-negative, non-spore-forming, rod-shaped, motile and mesophilic bacteria, designated as strains AN17-1^T and AN17-2^T, were isolated from deep-marine sediments collected from the western Pacific Ocean. The phylogenetic analysis based on the 16S rRNA gene with the most closely related species showed 98.5 and 98.8% similarities of strains AN17-1^T and AN17-2^T with Vallitalea guaymasensis Ra1766G1^T, respectively. The genome sizes and G+C contents of strains AN17-1^T and AN17-2^T were 6.0 Mb and 30.3 mol% and 5.4 Mb and 30.9 mol%, respectively. The genome-to-genome distance and the average nucleotide identity values between strains AN17-1^T and AN17-2^T and V. guaymasensis Ra1766G1^T were lower than the thresholds for species delimitation. Elemental sulphur, sulphate, thiosulphate, sulphite, fumarate, nitrate and nitrite were not used as terminal electron acceptors by strains AN17-1^T and AN17-2^T. The most abundant fatty acids of strains AN17-1^T and AN17-2^T were iso-C_15:0 and C_16:0, respectively. The commonly detected polar lipids of both strains were diphosphatidylglycerol, phosphatidylglycerol, phosphoglycolipid, glycolipid, two unidentified phospholipids and one unidentified polar lipid. The results suggest that strains AN17-1^T and AN17-2^T represent novel species of the genus Vallitalea. Therefore, the new names, Vallitalea sediminicola sp. nov. and Vallitalea maricola sp. nov., are proposed for strains AN17-1^T (=NBRC 115486^T=DSM 116091^T) and AN17-2^T (=NBRC 115487^T=DSM 116092^T) as the type strains, respectively.