title: Description of Variovorax humicola sp. nov., isolated from a forest topsoil.
abstract: Employing a modified cultivation method, we studied two bacterial strains, UC10 and UC38T, 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 GXGD002T, with 98.6 % similarity. Strains UC10 and UC38Twere 98.0 % similar to V.ariovorax soli GH9-3T; 97.8 % to V.ariovorax dokdonensis DS-43T; 97.3-97.7 % to V.ariovorax ginsengisoli Gsoil 3165T; 97.7-98.0 % to V.ariovorax paradoxus IAM 12373T; 97.4-97.6 % to V.ariovorax defluvii 2C1-bT; and 97.3-97.4 % to V.ariovorax boronicumulans BAM-48T. 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 UC38T. Moreover, genomic DNA similarity between these novel strains and reference strains of the genus Variovoraxwas less than the 70 %. Based on these results, strain UC38Twas designated a representative of a novel species of the genus Variovorax, with the proposed name Variovorax humicola sp. nov. The type strain is UC38T(=KACC 18501T=NBRC 111520T).
authors.affiliation: 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.
authors.forename: Tuan Manh
authors.initials: TM
authors.lastname: Nguyen
authors.affiliation: Department of Life Science, College of Natural Sciences, Kyonggi University, Gyeonggi-Do 443-760, South Korea.
authors.forename: Jaisoo
authors.initials: J
authors.lastname: Kim
mesh_terms: D015373:Bacterial Typing Techniques; D001482:Base Composition; D042621:Comamonadaceae / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000235:genetics; D005227:Fatty Acids / Q000737:chemistry; D065928:Forests; D009693:Nucleic Acid Hybridization; D010743:Phospholipids / Q000737:chemistry; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D056910:Republic of Korea; D017422:Sequence Analysis, DNA; D012988:Soil Microbiology; D014451:Ubiquinone / Q000737:chemistry
chemical_list: D004269:DNA, Bacterial; D005227:Fatty Acids; D010743:Phospholipids; D012336:RNA, Ribosomal, 16S; D014451:Ubiquinone; C030778:ubiquinone 8
keywords: Proteobacteria; Variovorax humicola sp. nov.; soil; taxonomy