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Rhodococcus daqingensis sp. nov., isolated from petroleum-contaminated soil

Wang, Lili, Zhang, Liguo, Zhang, Xiaofei, Zhang, Shuquan, Yang, Lei, Yuan, Hongmei, Chen, Jing, Liang, Chunbo, Huang, Wengong, Liu, Jianxin, Zhao, Yuanling, Yang, Qian
Antonie van Leeuwenhoek 2019 v.112 no.5 pp. 695-702
arabinose, chemotaxonomy, galactose, glucose, hydrogen, menaquinones, mycolic acids, new species, nucleic acid hybridization, nucleotide sequences, pH, peptidoglycans, phenotype, phosphatidylethanolamines, phylogeny, polluted soils, ribosomal DNA, ribosomal RNA, sequence homology, temperature, China
A novel Gram-stain positive, aerobic, non-motile bacterial strain, designated Z1ᵀ, was isolated from a sample of petroleum-contaminated soil collected in Daqing, Heilongjiang province, China and characterised with a series of taxonomic approaches. The morphological and chemotaxonomic properties of the isolate were typical of those of members of the genus Rhodococcus. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain Z1ᵀ belongs to the genus Rhodococcus and clustered with Rhodococcus maanshanensis DSM 44675ᵀ (99.2%, sequence similarity) and Rhodococcus tukisamuensis JCM 11308ᵀ (97.9%), respectively. However, the DNA–DNA hybridizations between strain Z1ᵀ and R. maanshanensis DSM 44675ᵀ and R. tukisamuensis JCM 11308ᵀ were both less than 70%. The optimal growth temperature and pH for strain Z1ᵀ were found to be at 28 °C and at pH 7.0. The peptidoglycan was found to contain meso-diaminopimelic acid; arabinose, galactose and glucose were detected as diagnostic sugars. The main polar lipids were identified as diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside and an unidentified lipid; MK-8(H₂) was found as the major menaquinone. The major fatty acids were identified as C₁₆:₀, 10-methyl C₁₈:₀ and C₁₈:₁ω9c. Mycolic acids were found to be present. The G + C content of the genomic DNA was determined to be 66.7 mol%. Based on a comparative analysis of phenotypic and genotypic characteristics, in combination with DNA–DNA hybridization results, strain Z1ᵀ can be distinguished from the type strains of its two close neighbours as a novel species of the genus Rhodococcus, for which the name Rhodococcus daqingensis sp. nov. is proposed. The type strain is Z1ᵀ (= CGMCC 1.13630ᵀ = DSM 107227ᵀ).