Microorganisms Bank, Iranian Biological Resource Centre (IBRC), ACECR Tehran, Iran.
Extremophile Laboratory, Department of Microbiology, School of Biology, College of Science, University of Tehran, Tehran, Iran.
Int J Syst Evol Microbiol. 2012 Jul;62(Pt 7):1521-1527. doi: 10.1099/ijs.0.031971-0. Epub 2011 Aug 19.
Two Gram-staining-negative, red- and orange-pigmented, non-motile, rod-shaped, extremely halophilic bacteria, designated strains CB7(T) and DGO(T), were isolated from Aran-Bidgol salt lake, Iran. Growth occurred at NaCl concentrations of between 2 and 5 M NaCl and the isolates grew optimally with 3 M NaCl. The optimum pH and temperature for growth of the two strains were pH 7.5 and 37 °C, and they were able to grow over pH and temperature ranges of pH 6-8 and 25-50 °C. The predominant fatty acids of the two isolates were C(18:1)ω7c, iso-C(15:0) and summed feature 3 (C(16:1)ω7c and/or iso-C(15:0) 2-OH). The polar lipid pattern of the two isolates consisted of diphosphatidylglycerol, phosphatidylcholine, three unidentified lipids, one unidentified aminolipid and three unidentified glycolipids. The only quinone present was menaquinone 7 (MK-7). The G+C contents of the genomic DNA of strains CB7(T) and DGO(T) were 64.8 and 65.6 mol%, respectively. 16S rRNA gene sequence analysis indicated that strains CB7(T) and DGO(T) were related to Salinibacter ruber in the phylum Bacteroidetes. Levels of 16S rRNA gene sequence similarity between strains CB7(T) and DGO(T) and Salinibacter ruber DSM 13855(T) were 93.2 and 93.6%, respectively. The two novel strains shared 98.9% 16S rRNA gene sequence similarity. DNA-DNA hybridization experiments between strains CB7(T) and DGO(T) and Salinibacter ruber DSM 13855(T) indicated levels of relatedness of 44 and 52%, respectively, while the level of relatedness between the two new isolates was 53%. Chemotaxonomic data supported the placement of strains CB7(T) and DGO(T) in the genus Salinibacter. DNA-DNA hybridization studies and biochemical and physiological characterization allowed strains CB7(T) and DGO(T) to be differentiated from Salinibacter ruber and from each other. They are therefore considered to represent two novel species of the genus Salinibacter, for which the names Salinibacter iranicus sp. nov. (type strain CB7(T)=IBRC-M 10036(T)=CGMCC 1.11003(T)) and Salinibacter luteus sp. nov. (type strain DGO(T)=IBRC-M 10423(T)=CGMCC 1.11002(T)) are proposed. Emended descriptions of the genus Salinibacter and of Salinibacter ruber are also presented.
两株革兰氏阴性、红橙色、非运动、杆状、极端嗜盐的细菌，分别命名为 CB7(T)和 DGO(T)，从伊朗的阿兰-比多格尔盐湖中分离得到。它们在 2-5 M NaCl 浓度下生长，在 3 M NaCl 下生长最佳。这两株菌的最适生长 pH 值和温度分别为 pH7.5 和 37°C，能够在 pH6-8 和 25-50°C 的温度范围内生长。这两株菌的主要脂肪酸为 C(18:1)ω7c、iso-C(15:0)和 sum feature 3(C(16:1)ω7c 和/或 iso-C(15:0)2-OH)。两株菌的极性脂图谱由双磷脂酰甘油、磷脂酰胆碱、三种未鉴定的脂类、一种未鉴定的胺脂类和三种未鉴定的糖脂类组成。唯一存在的醌类物质是menaquinone 7 (MK-7)。菌株 CB7(T)和 DGO(T)的基因组 DNA G+C 含量分别为 64.8 和 65.6 mol%。16S rRNA 基因序列分析表明，菌株 CB7(T)和 DGO(T)与厚壁菌门的 Salinibacter ruber 有关。菌株 CB7(T)和 DGO(T)与 Salinibacter ruber DSM 13855(T)的 16S rRNA 基因序列相似度分别为 93.2%和 93.6%。两株新菌株的 16S rRNA 基因序列相似度为 98.9%。CB7(T)和 DGO(T)与 Salinibacter ruber DSM 13855(T)之间的 DNA-DNA 杂交实验表明，它们之间的相关性分别为 44%和 52%，而两株新分离株之间的相关性为 53%。化学生物分类学数据支持将菌株 CB7(T)和 DGO(T)归入 Salinibacter 属。DNA-DNA 杂交研究以及生化和生理特性鉴定表明，菌株 CB7(T)和 DGO(T)可与 Salinibacter ruber 以及彼此之间区分开来。因此，它们被认为代表了 Salinibacter 属的两个新种，分别命名为 Salinibacter iranicus sp. nov.（模式菌株 CB7(T)=IBRC-M 10036(T)=CGMCC 1.11003(T)）和 Salinibacter luteus sp. nov.（模式菌株 DGO(T)=IBRC-M 10423(T)=CGMCC 1.11002(T)）。同时还提出了对 Salinibacter 属和 Salinibacter ruber 的修订描述。
