Lai Qiliang, Li Guizhen, Liu Xiupian, Du Yaping, Sun Fengqin, Shao Zongze
State Key Laboratory Breeding Base of Marine Genetic Resources; Key Laboratory of Marine Genetic Resources, Third Institute of Oceanography, SOA; Key Laboratory of Marine Genetic Resources of Fujian Province, Xiamen, 361005, China.
Antonie Van Leeuwenhoek. 2015 Apr;107(4):1065-74. doi: 10.1007/s10482-015-0398-2. Epub 2015 Feb 7.
A taxonomic study was carried out on strain 22II-S11g(T), 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 0.5-9 % and at temperatures of 10-41 °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-S11g(T) was found to be most closely related to Oceanicola batsensis HTCC2597(T) (97.26 %), followed by Oceanicola nitratireducens JLT1210(T) (96.39 %), whilst other species of genus Oceanicola shared 94.00-96.34 % sequence similarity. However, it showed low similarity to Oceanicola granulosus HTCC2516(T) (94.79 %), the type species of the genus Oceanicola. Phylogenetic analysis showed that strain 22II-S11g(T) formed a clade with six species currently classified in the genus Oceanicola, but strain O. granulosus HTCC2516(T) and strain O. litoreus M-M22(T) clustered with two other genera respectively. The ANI values between strain 22II-S11g(T) and two type strains (O. batsensis HTCC2597(T) and O. granulosus HTCC2516(T)) are 91.86 and 91.81 % respectively. The digital DNA-DNA hybridization estimate values between strain 22II-S11g(T) and two type strains (O. batsensis HTCC2597(T) and O. granulosus HTCC2516(T)) 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-S11g(T) should not be assigned to the genus Oceanicola; consequently strain 22II-S11g(T) 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-S11g(T) = KCTC 42004(T) = LMG 27424(T) = MCCC 1A09160(T)). 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 HTCC2597(T) = ATCC BAA-863(T) = DSM 15984(T) = KCTC 12145(T)); Oceanicola marinus should be transferred to the genus Pseudooceanicola as Pseudooceanicola marinus comb. nov. (type strain AZO-C(T) = LMG 23705(T) = BCRC 17591(T)); O. nitratireducens should be transferred to the genus Pseudooceanicola as Pseudooceanicola nitratireducens comb. nov. (type strain JLT1210(T) = LMG 24663(T) = CGMCC 1.7292(T)); Oceanicola nanhaiensis should be transferred to the genus Pseudooceanicola as Pseudooceanicola nanhaiensis comb. nov. (type strain SS011B1-20(T) = LMG 23508(T) = CGMCC 1.6293(T)); Oceanicola antarcticus should be transferred to the genus Pseudooceanicola as Pseudooceanicola antarcticus comb. nov. (type strain Ar-45(T) = CGMCC 1.12662(T) = LMG 27868(T)); and Oceanicola flagellatus should be transferred to the genus Pseudooceanicola as Pseudooceanicola flagellatus comb. nov. (type strain DY470(T) = CGMCC 1.12664(T) = LMG 27871(T)).
对从大西洋表层海水中分离得到的22II-S11g(T)菌株进行了分类学研究。该细菌为革兰氏阴性,无鞭毛的杆状,氧化酶阳性,过氧化氢酶弱阳性。在NaCl浓度为0.5-9%和温度为10-41°C的条件下可观察到生长。该分离株不能水解明胶,不能将硝酸盐还原为亚硝酸盐,不能降解七叶苷和吐温80。基于16S rRNA基因序列相似性,发现22II-S11g(T)菌株与巴氏海栖菌HTCC2597(T)关系最为密切(97.26%),其次是硝酸盐还原海栖菌JLT1210(T)(96.39%),而海栖菌属的其他物种序列相似性为94.00-96.34%。然而,它与海栖菌属的模式种颗粒海栖菌HTCC2516(T)的相似性较低(94.79%)。系统发育分析表明,22II-S11g(T)菌株与目前分类在海栖菌属中的六个物种形成一个进化枝,但颗粒海栖菌HTCC2516(T)菌株和滨海海栖菌M-M22(T)菌株分别与另外两个属聚类。22II-S11g(T)菌株与两个模式菌株(巴氏海栖菌HTCC2597(T)和颗粒海栖菌HTCC2516(T))的ANI值分别为91.86%和91.81%。22II-S11g(T)菌株与两个模式菌株(巴氏海栖菌HTCC2597(T)和颗粒海栖菌HTCC2516(T))的数字DNA-DNA杂交估计值分别为23.4±2.4%和20.0±2.3%。主要脂肪酸被鉴定为总和特征8(C18:1 ω7c/ω6c)、C16:0、C18:1 ω7c 11-甲基和C12:0 3OH。根据基因组草图序列确定的G+C含量为64.1 mol%。呼吸醌被确定为Q-10(100%)。在极性脂质中鉴定出磷脂酰乙醇胺、磷脂酰甘油、一种氨基脂质、磷脂酰胆碱、一种磷脂和三种脂质。综合的基因型和表型数据还表明,22II-S11g(T)菌株不应归入海栖菌属;因此,得出结论,22II-S11g(T)菌株代表红杆菌科一个新属的一个新物种,为此提出新属名假海栖菌属(Pseudooceanicola),新种名大西洋假海栖菌(Pseudooceanicola atlanticus)(模式菌株22II-S11g(T)=KCTC 42004(T)=LMG 27424(T)=MCCC 1A09160(T))。六个分类错误的物种应转移到新属假海栖菌属,如下:巴氏海栖菌应作为巴氏假海栖菌(Pseudooceanicola batsensis)转移到假海栖菌属(模式菌株HTCC2597(T)=ATCC BAA-863(T)=DSM 15984(T)=KCTC 12145(T));海栖海栖菌应作为海栖假海栖菌(Pseudooceanicola marinus)转移到假海栖菌属(模式菌株AZO-C(T)=LMG 23705(T)=BCRC 17591(T));硝酸盐还原海栖菌应作为硝酸盐还原假海栖菌(Pseudooceanicola nitratireducens)转移到假海栖菌属(模式菌株JLT1210(T)=LMG 24663(T)=CGMCC 1.7292(T));南海海栖菌应作为南海假海栖菌(Pseudooceanicola nanhaiensis)转移到假海栖菌属(模式菌株SS011B1-20(T)=LMG 23508(T)=CGMCC 1.6293(T));南极海栖菌应作为南极假海栖菌(Pseudooceanicola antarcticus)转移到假海栖菌属(模式菌株Ar-45(T)=CGMCC 1.12662(T)=LMG 27868(T));鞭毛海栖菌应作为鞭毛假海栖菌(Pseudooceanicola flagellatus)转移到假海栖菌属(模式菌株DY470(T)=CGMCC 1.12664(T)=LMG 27871(T))。