Nguyen Tuan Manh, Kim Jaisoo
Department of Life Science, College of Natural Sciences, Kyonggi University, Gyeonggi-Do 443-760, South Korea.
Thai Nguyen University of Agriculture and Forestry, Quyet Thang commune, Thai Nguyen City, Vietnam.
Int J Syst Evol Microbiol. 2016 Jul;66(7):2520-2527. doi: 10.1099/ijsem.0.001082. Epub 2016 Apr 15.
Employing a modified cultivation method, we studied two bacterial strains, UC10 and UC38, found on the Kyonggi University campus, Suwon in Gyeonggi-Do province, South Korea. These strains were non-spore-forming, Gram-stain-negative, motile and rod-shaped. Growth occurred in the presence of 0-2 % (w/v) NaCl, at pH 4-9 and a temperature range of 4-35 °C. On an R2A agar plate incubated for 5 days at 28 °C, irregular, raised and pale-yellowish colonies were observed. Comparative analysis of nearly full-length 16S rRNA gene sequences indicated that these strains were closely related to Variovorax guangxiensis GXGD002, with 98.6 % similarity. Strains UC10 and UC38 were 98.0 % similar to V.ariovorax soli GH9-3; 97.8 % to V.ariovorax dokdonensis DS-43; 97.3-97.7 % to V.ariovorax ginsengisoli Gsoil 3165; 97.7-98.0 % to V.ariovorax paradoxus IAM 12373; 97.4-97.6 % to V.ariovorax defluvii 2C1-b; and 97.3-97.4 % to V.ariovorax boronicumulans BAM-48. The predominant ubiquinone was Q-8. The primary polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The major fatty acids were C16 : 0, summed feature 3 (C16 : 1ω7c and/or C16 : 1ω6c), summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c) and C17 : 0 cyclo. DNA-DNA hybridization assays indicated 89.2-91.4 % genomic DNA similarity between strains UC10 and UC38. Moreover, genomic DNA similarity between these novel strains and reference strains of the genus Variovoraxwas less than the 70 %. Based on these results, strain UC38 was designated a representative of a novel species of the genus Variovorax, with the proposed name Variovorax humicola sp. nov. The type strain is UC38 (=KACC 18501=NBRC 111520).
采用改良培养方法，我们研究了在韩国京畿道水原市庆熙大学校园发现的两株细菌菌株UC10和UC38。这些菌株不形成芽孢，革兰氏染色阴性，具运动性，呈杆状。在0-2%（w/v）NaCl、pH值4-9以及4-35°C温度范围内均可生长。在28°C下于R2A琼脂平板上培养5天，观察到不规则、凸起且淡黄色的菌落。对近乎全长的16S rRNA基因序列进行比较分析表明，这些菌株与广西贪噬菌GXGD002密切相关，相似度为98.6%。菌株UC10和UC38与土壤贪噬菌GH9-3的相似度为98.0%；与独岛贪噬菌DS-43的相似度为97.8%；与人参贪噬菌Gsoil 3165的相似度为97.3-97.7%；与奇异贪噬菌IAM 12373的相似度为97.7-98.0%；与污水贪噬菌2C1-b的相似度为97.4-97.6%；与硼酸贪噬菌BAM-48的相似度为97.3-97.4%。主要泛醌为Q-8。主要极性脂为双磷脂酰甘油、磷脂酰甘油和磷脂酰乙醇胺。主要脂肪酸为C16 : 0、特征性总和3（C16 : 1ω7c和/或C16 : 1ω6c）、特征性总和8（C18 : 1ω7c和/或C18 : 1ω6c）以及C17 : 0环丙烷脂肪酸。DNA-DNA杂交分析表明，菌株UC10和UC38之间的基因组DNA相似度为89.2-91.4%。此外，这些新菌株与贪噬菌属参考菌株之间的基因组DNA相似度低于70%。基于这些结果，菌株UC38被指定为贪噬菌属一个新物种的代表，提议命名为栖土贪噬菌（Variovorax humicola sp. nov.）。模式菌株为UC38（=KACC 18501=NBRC 111520）。
