Lee On On, Tsoi Mandy M Y, Li Xiancui, Wong Po-Keung, Qian Pei-Yuan
Coastal Marine Laboratory/Department of Biology, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR.
Department of Biology, Chinese University of Hong Kong, Shatin, N. T., Hong Kong SAR.
Int J Syst Evol Microbiol. 2007 Aug;57(Pt 8):1919-1924. doi: 10.1099/ijs.0.64801-0.
A Gram-negative, non-pigmented, ovoid-shaped, strictly aerobic, catalase- and oxidase-positive and highly halotolerant bacterial strain that was devoid of swimming and gliding motility, designated UST050418-052(T), was isolated from the surface of the marine sponge Halichondria panicea at Friday Harbor, WA, USA. Strain UST050418-052(T) required NaCl for growth and could tolerate salt concentrations of up to 18 %. The primary respiratory quinone was ubiquinone-10 and the DNA G+C content was 57.8 mol%. The predominant fatty acids were the saturated fatty acids 16 : 0 and 18 : 0 and the monounsaturated fatty acids 18 : 1 omega 7c and 18 : 1 omega 9c, altogether representing 82.9 % of the total. Phylogenetic analysis based on the 16S rRNA gene sequence placed UST050418-052(T) in a distinct lineage within the Roseobacter clade in the family Rhodobacteraceae, with 95.0-95.8 % sequence similarity to members of the nearest genus Thalassobius. The DNA-DNA relatedness between UST050418-052(T) and Thalassobius gelatinovorus IAM 12617(T) was 9 %. Strain UST050418-052(T) could be differentiated from closely related members of the Roseobacter clade by a number of chemotaxonomic and phenotypic characteristics such as its distinct fatty acid profile, ability to reduce nitrate to nitrite and inability to utilize citrate, succinate, L-arginine and pyruvate. Based on the phylogenetic, chemotaxonomic and phenotypic evidence presented in this study, we suggest that strain UST050418-052(T) represents a novel genus in the family Rhodobacteraceae. The name Thalassococcus halodurans gen. nov., sp. nov., is thus proposed. The type strain of Thalassococcus halodurans is UST050418-052(T) (=JCM 13833(T) =NRRL B-41465(T)).
从美国华盛顿州星期五港的海洋海绵Halichondria panicea表面分离出一株革兰氏阴性、无色素、卵形、严格需氧、过氧化氢酶和氧化酶阳性且高度耐盐的细菌菌株，命名为UST050418-052(T)。菌株UST050418-052(T)生长需要NaCl，能耐受高达18%的盐浓度。主要呼吸醌为泛醌-10，DNA G+C含量为57.8 mol%。主要脂肪酸为饱和脂肪酸16 : 0和18 : 0以及单不饱和脂肪酸18 : 1 ω7c和18 : 1 ω9c，共占总量的82.9%。基于16S rRNA基因序列的系统发育分析将UST050418-052(T)置于红杆菌科红杆菌属内一个独特的分支中，与最接近的Thalassobius属成员的序列相似性为95.0 - 95.8%。UST050418-052(T)与Thalassobius gelatinovorus IAM 12617(T)之间的DNA-DNA相关性为9%。菌株UST050418-052(T)可通过一些化学分类和表型特征与红杆菌属的近缘成员区分开来，如独特的脂肪酸谱、将硝酸盐还原为亚硝酸盐的能力以及不能利用柠檬酸盐、琥珀酸盐、L-精氨酸和丙酮酸的能力。基于本研究中提供的系统发育、化学分类和表型证据，我们建议菌株UST050418-052(T)代表红杆菌科中的一个新属。因此，提出新属名Thalassococcus halodurans，新种名Thalassococcus halodurans。Thalassococcus halodurans的模式菌株为UST050418-052(T) (=JCM 13833(T) =NRRL B-41465(T))。
