Jeju Center, Korea Basic Science Institute, Jeju, 690-140, Republic of Korea.
Antonie Van Leeuwenhoek. 2014 Mar;105(3):603-12. doi: 10.1007/s10482-014-0115-6. Epub 2014 Jan 18.
A novel, red-pigmented, pleomorphic and short rod-shaped haloarchaeon, designated B8(T), was isolated from a salt-fermented seafood. Strain B8(T) was found to be able to grow at 20-45 °C, in the presence of 15-30 % (w/v) NaCl and at pH 7.0-9.0. The optimum requirements were found to be a temperature range of 35-40 °C, pH 8.0 and the presence of 25 % NaCl. The cells of strain B8(T) were observed to be Gram-staining negative and lysed in distilled water. Anaerobic growth did not occur in the presence of nitrate, L-arginine, dimethyl sulfoxide or trimethylamine N-oxide. The catalase and oxidase activities were found to be positive and nitrate was reduced in aerobic conditions. Tween 20, 40 and 80 were found to be hydrolyzed, whereas casein, gelatin and starch were not hydrolyzed. Indole or H2S was not formed and urease activity was not detected. A phylogenetic analysis based on the 16S rRNA gene sequences indicated that strain B8(T) is most closely related to members of the genus Halorubrum in the family Halobacteriaceae. Strain B8(T) was found to have three 16S rRNA genes, rrnA, rrnB and rrnC; similarities between the 16S rRNA gene sequences are 99.0-99.8 %. Strain B8(T) shared 99.0 % 16S rRNA gene sequence similarity with Halorubrum (Hrr.) lipolyticum JCM 13559(T) and Hrr. saccharovorum DSM 1137(T), 98.8 % with Hrr. kocurii JCM 14978(T), 98.3 % with Hrr. lacusprofundi DSM 5036(T), 98.0 % with Hrr. arcis JCM 13916(T), 97.7 % with Hrr. aidingense JCM 13560(T) and 97.0 % with Hrr. aquaticum JCM 14031(T), as well as 93.7-96.5 % with other type strains in the genus Halorubrum. The RNA polymerase subunit B' gene sequence similarity of strain B8(T) with Hrr. kocurii JCM 14978(T) is 97.2 % and lower with other members of the genus Halorubrum. DNA-DNA hybridization experiments showed that strain B8(T) shared equal or lower than 50 % relatedness with reference species in the genus Halorubrum. The genomic DNA G+C content of strain B8(T) was determined to be 64.6 mol%. The major isoprenoid quinone of strain B8(T) was identified as menaquinone-8 and the major polar lipids as phosphatidylglycerol, phosphatidylglycerol phosphate methyl ester, phosphatidylglycerol sulfate, sulfated mannosyl glucosyl diether and an unidentified phospholipid. Based on this polyphasic taxonomic study, strain B8(T) is considered to represent a new species in the genus Halorubrum, for which the name Hrr. halophilum sp. nov. is proposed. The type strain is B8(T) (=JCM 18963(T) = CECT 8278(T)).
一株新型、红色、多形和短杆状的嗜盐古菌，命名为 B8(T)，从一种盐发酵海鲜中分离得到。研究发现，菌株 B8(T)能够在 20-45°C、15-30%（w/v）NaCl 和 pH7.0-9.0 的条件下生长。最佳要求为温度范围 35-40°C、pH8.0 和存在 25%NaCl。观察到菌株 B8(T)的细胞革兰氏染色阴性，在蒸馏水中裂解。在存在硝酸盐、L-精氨酸、二甲基亚砜或三甲胺 N-氧化物的情况下，不会发生厌氧生长。发现细胞的过氧化氢酶和氧化酶活性均为阳性，在需氧条件下可还原硝酸盐。发现菌株 B8(T)可水解吐温 20、40 和 80，但不能水解酪蛋白、明胶和淀粉。不形成吲哚或 H2S，脲酶活性也未检测到。基于 16S rRNA 基因序列的系统发育分析表明，菌株 B8(T)与盐杆菌科盐杆菌属的成员最为密切相关。研究发现菌株 B8(T)有三个 16S rRNA 基因，rrnA、rrnB 和 rrnC；16S rRNA 基因序列之间的相似性为 99.0-99.8%。菌株 B8(T)与 Halorubrum (Hrr.) lipolyticum JCM 13559(T)和 Hrr. saccharovorum DSM 1137(T)的 16S rRNA 基因序列相似性为 99.0%，与 Hrr. kocurii JCM 14978(T)的相似性为 98.8%，与 Hrr. lacusprofundi DSM 5036(T)的相似性为 98.3%，与 Hrr. arcis JCM 13916(T)的相似性为 98.0%，与 Hrr. aidingense JCM 13560(T)的相似性为 97.7%，与 Hrr. aquaticum JCM 14031(T)的相似性为 97.0%，与其他盐杆菌属的模式菌株的相似性为 93.7-96.5%。与 Hrr. kocurii JCM 14978(T)的 RNA 聚合酶亚基 B'基因序列相似性为 97.2%，与其他盐杆菌属成员的相似性较低。DNA-DNA 杂交实验表明，菌株 B8(T)与盐杆菌属的参考种的相关性为 50%或更低。菌株 B8(T)的基因组 DNA G+C 含量为 64.6 mol%。菌株 B8(T)的主要类异戊二烯醌为menaquinone-8，主要极性脂为磷脂酰甘油、磷脂酰甘油磷酸甲酯、磷脂酰甘油硫酸酯、硫酸化甘露糖葡糖基二醚和一种未鉴定的磷脂。基于这种多相分类学研究，菌株 B8(T)被认为代表了盐杆菌属的一个新种，建议将其命名为 Hrr. halophilum sp. nov.。该模式株为 B8(T)=JCM 18963(T)= CECT 8278(T)。
