文摘

A taxonomic study was carried out on strain 22II-S11gT, which was isolated from the surface seawater of the Atlantic Ocean. The bacterium was found to be Gram-negative, rod shaped without flagellum, oxidase positive and weakly catalase positive. Growth was observed at NaCl concentrations of 0.5-?% and at temperatures of 10-1?°C. The isolate was incapable of gelatin hydrolysis and unable to reduce nitrate to nitrite, degrade aesculin and Tween 80. On the basis of 16S rRNA gene sequence similarity, strain 22II-S11gT was found to be most closely related to Oceanicola batsensis HTCC2597T (97.26?%), followed by Oceanicola nitratireducens JLT1210T (96.39?%), whilst other species of genus Oceanicola shared 94.00-6.34?% sequence similarity. However, it showed low similarity to Oceanicola granulosus HTCC2516T (94.79?%), the type species of the genus Oceanicola. Phylogenetic analysis showed that strain 22II-S11gT formed a clade with six species currently classified in the genus Oceanicola, but strain O. granulosus HTCC2516T and strain O. litoreus M-M22T clustered with two other genera respectively. The ANI values between strain 22II-S11gT and two type strains (O. batsensis HTCC2597T and O. granulosus HTCC2516T) are 91.86 and 91.81?% respectively. The digital DNA–DNA hybridization estimate values between strain 22II-S11gT and two type strains (O. batsensis HTCC2597T and O. granulosus HTCC2516T) are 23.4?±?2.4 and 20.0?±?2.3?%, respectively. The principal fatty acids were identified as summed feature 8 (C18:1 ω7c/ω6c), C16:0, C18:1 ω7c11-methyl and C12:0 3OH. The G+C content determined from the draft genome sequence is 64.1?mol%. The respiratory quinone was determined to be Q-10 (100?%). Phosphatidylethanolamine, phosphatidylglycerol, an aminolipid, phosphatidylcholine, a phospholipid and three lipids were identified in the polar lipids. The combined genotypic and phenotypic data also show that strain 22II-S11gT should not be assigned to the genus Oceanicola; consequently strain 22II-S11gT is concluded to represent a novel species of a novel genus in the family Rhodobacteraceae, for which the name Pseudooceanicola atlanticus gen. nov., sp. nov. is proposed (type strain 22II-S11gT?=?KCTC 42004T?=?LMG 27424T?=?MCCC 1A09160T). Six misclassified species should be transferred to the novel genus Pseudooceanicola as follows: O. batsensis should be transferred to the genus Pseudooceanicola as Pseudooceanicola batsensis comb. nov. (type strain HTCC2597T?=?ATCC BAA-863T?=?DSM 15984T?=?KCTC 12145T); Oceanicola marinus should be transferred to the genus Pseudooceanicola as Pseudooceanicola marinus comb. nov. (type strain AZO-CT?=?LMG 23705T?=?BCRC 17591T); O. nitratireducens should be transferred to the genus Pseudooceanicola as Pseudooceanicola nitratireducens comb. nov. (type strain JLT1210T?=?LMG 24663T?=?CGMCC 1.7292T); Oceanicola nanhaiensis should be transferred to the genus Pseudooceanicola as Pseudooceanicola nanhaiensis comb. nov. (type strain SS011B1-20T?=?LMG 23508T?=?CGMCC 1.6293T); Oceanicola antarcticus should be transferred to the genus Pseudooceanicola as Pseudooceanicola antarcticus comb. nov. (type strain Ar-45T?=?CGMCC 1.12662T?=?LMG 27868T); and Oceanicola flagellatus should be transferred to the genus Pseudooceanicola as Pseudooceanicola flagellatus comb. nov. (type strain DY470T?=?CGMCC 1.12664T?=?LMG 27871T).