Singh Harjodh, Kaur Manpreet, Sharma Shivani, Kaur Lakhwinder, Mishra Sunita, Tanuku Naga Radha Srinivas, Pinnaka Anil Kumar
Academy of Scientific and Innovative Research (AcSIR), CSIR Campus, Chennai, India.
MTCC-Microbial Type Culture Collection and Gene Bank, CSIR-Institute of Microbial Technology, Chandigarh 160036, India.
Int J Syst Evol Microbiol. 2018 May;68(5):1665-1671. doi: 10.1099/ijsem.0.002726. Epub 2018 Apr 4.
An aerobic, endospore-forming, haloalkali-tolerant, Gram-stain-positive, motile, rod-shaped bacterium, designated strain AK73, was isolated from a sediment sample collected from Sambhar lake, Jaipur, Rajasthan, India. Colonies were circular, 1-2 mm in diameter, glossy, smooth, yellowish and convex with an entire margin after 48 h growth on marine agar at pH 9 and 37 °C. Growth occurred at 15-42 °C, 0-10 % (w/v) NaCl and at a pH range of 7-12. Strain AK73 was positive for catalase and arginine dihydrolase 2 activities, hydrolysis of Tweens 20, 40 and 80, and negative for esculinase, caseinase, gelatinase, β-galactosidase, lipase (Tween 60) and urease activities. The fatty acids were dominated by branched iso-, anteiso-, saturated fatty acids with a high abundance of iso-C15 : 0, anteiso-C15 : 0, C16 : 0 and anteiso-C17 : 0; MK-7 was the major menaquinone. The cell-wall peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, one unidentified aminophospholipid, four unidentified phospholipids and three unidentified lipids. The DNA G+C content of strain AK73 was 54 mol%. Analysis based on comparative 16S rRNA gene sequence analysis indicated that Bacillus alcalophilus was the nearest phylogenetic neighbour, with a pair-wise sequence similarity of 96.0 %. Phylogenetic analysis showed that strain AK73 formed a separate lineage but was loosely associated with a peripheral cluster of organisms that contained Bacillus gibsonii, Bacillus murimartini and Bacillus plakortidis with similarity values of 93.6, 93.5 and 93.4 %, respectively. Based on its phenotypic characteristics and on phylogenetic inference, strain AK73 represents a novel species of the genus Bacillus, for which the name Bacillus alkalilacus sp. nov. is proposed. The type strain is AK73 (=JCM 32184=MTCC 12637=KCTC 33880).
从印度拉贾斯坦邦斋浦尔桑伯尔湖采集的沉积物样本中分离出一株需氧、产芽孢、耐盐碱、革兰氏染色阳性、具运动性的杆状细菌，命名为AK73菌株。该菌株在pH 9、37℃的海洋琼脂培养基上培养48小时后，菌落呈圆形，直径1-2毫米，有光泽、光滑、淡黄色且凸起，边缘整齐。其生长温度范围为15-42℃，NaCl浓度为0-10%（w/v），pH范围为7-12。AK73菌株过氧化氢酶和精氨酸双水解酶2活性呈阳性，能水解吐温20、40和80，而七叶灵酶、酪蛋白酶、明胶酶、β-半乳糖苷酶、脂肪酶（吐温60）和脲酶活性呈阴性。脂肪酸以支链异、anteiso、饱和脂肪酸为主，其中异-C15:0、anteiso-C15:0、C16:0和anteiso-C17:0含量较高；MK-7是主要的甲基萘醌。细胞壁肽聚糖含有内消旋二氨基庚二酸作为诊断性二氨基酸。极性脂质为双磷脂酰甘油、磷脂酰乙醇胺、磷脂酰甘油、一种未鉴定的氨基磷脂、四种未鉴定的磷脂和三种未鉴定的脂质。AK73菌株的DNA G+C含量为54摩尔%。基于比较16S rRNA基因序列分析的结果表明，嗜碱芽孢杆菌是其最近的系统发育邻种，序列相似性为96.0%。系统发育分析表明，AK73菌株形成了一个独立的分支，但与包含吉氏芽孢杆菌、鼠芽孢杆菌和普拉科尔蒂芽孢杆菌的生物外围聚类松散相关，相似性值分别为93.6%、93.5%和93.4%。基于其表型特征和系统发育推断，AK73菌株代表芽孢杆菌属的一个新物种，为此提出芽孢杆菌碱湖种（Bacillus alkalilacus sp. nov.）的名称。模式菌株为AK73（=JCM 32184=MTCC 12637=KCTC 33880）。
