Chaudhary Dhiraj Kumar, Kim Jaisoo
Department of Life Science, College of Natural Sciences, Kyonggi University, Suwon, Gyeonggi-Do 16227, Republic of Korea.
Int J Syst Evol Microbiol. 2018 May;68(5):1749-1756. doi: 10.1099/ijsem.0.002750. Epub 2018 Apr 5.
A Gram-stain-positive, non-motile, creamy-white and rod-coccus shaped actinobacterium, designated strain Ktm-20, capable of degrading petroleum oil was isolated from oil-contaminated soil. Strain Ktm-20 was able to grow at 15-37 °C, at pH 5.5-10.0 and at 0.0-2.0 % (w/v) NaCl concentration. This strain was taxonomically characterized by a polyphasic approach. The 16S rRNA gene sequence analysis showed that strain Ktm-20 belonged to the genus Rhodococcus and is closely related to Rhodococcus triatomae DSM 44892, Rhodococcus pedocola UC12, Rhodococcus wratislaviensis NBRC 100605, Rhodococcus agglutinans CFH S0262 and Rhodococcus canchipurensis MBRL 353T (98.8, 98.7, 98.5, 98.4 and 98.3 % gene sequence similarity, respectively). The only respiratory quinone was MK-8(H2); the major polar lipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylinositol and phosphatidylinositol mannoside; and the predominant fatty acids were C16 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c) and C18 : 1ω9c. The cell-wall peptidoglycan contained meso-diaminopimelic acid; and galactose, glucose, arabinose and ribose were detected as diagnostic sugars from whole-cell hydrolysates. Mycolic acids were detected. The DNA G+C content was 70.9 mol%. The DNA-DNA relatedness values between strain Ktm-20 and closely related species of the genus Rhodococcus were between 38.3-25.3 %, which falls below the threshold value of 70 % for the strain to be considered as novel. The morphological, physiological, chemotaxonomic and phylogenetic analyses clearly distinguished this strain from its closest phylogenetic neighbours. Thus, strain Ktm-20 represents a novel species of the genus Rhodococcus, for which the name Rhodococcus olei sp. nov. is proposed. The type strain is Ktm-20 (=KEMB 9005-695=KACC 19390=JCM 32206).
从石油污染土壤中分离出一株革兰氏阳性、无运动性、乳脂白色、杆球菌状的放线菌，命名为Ktm - 20菌株，该菌株能够降解石油。Ktm - 20菌株能够在15 - 37°C、pH值5.5 - 10.0以及NaCl浓度0.0 - 2.0%（w/v）的条件下生长。采用多相分类法对该菌株进行了分类学鉴定。16S rRNA基因序列分析表明，Ktm - 20菌株属于红球菌属，与三锥红球菌DSM 44892、土壤红球菌UC12、布拉格红球菌NBRC 100605、凝集红球菌CFH S0262和坎奇普拉红球菌MBRL 353T密切相关（基因序列相似性分别为98.8%、98.7%、98.5%、98.4%和98.3%）。唯一的呼吸醌为MK - 8（H2）；主要极性脂为磷脂酰乙醇胺、二磷脂酰甘油、磷脂酰肌醇和磷脂酰肌醇甘露糖苷；主要脂肪酸为C16 : 0、特征性总和3（C16 : 1ω7c和/或C16 : 1ω6c）和C18 : 1ω9c。细胞壁肽聚糖含有内消旋二氨基庚二酸；从全细胞水解物中检测到半乳糖、葡萄糖、阿拉伯糖和核糖作为诊断性糖类。检测到分枝菌酸。DNA G + C含量为70.9 mol%。Ktm - 20菌株与红球菌属密切相关物种之间的DNA - DNA相关性值在38.3 - 25.3%之间，低于将该菌株视为新物种的阈值70%。形态学、生理学、化学分类学和系统发育分析清楚地将该菌株与其最密切的系统发育邻居区分开来。因此，Ktm - 20菌株代表红球菌属的一个新物种，为此提出名为油红球菌（Rhodococcus olei sp. nov.）。模式菌株为Ktm - 20（=KEMB 9005 - 695 =KACC 19390 =JCM 32206）。
