Nocardioides asiaticus sp. nov. and Nocardioides pollutisoli sp. nov., isolated from oil-contaminated soil

Two Nocardioides isolates were obtained from oil-contaminated soil samples collected from Cheoin-gu, Yongin-si, Gyeonggi-do, South Korea (strain KR10-350 T ), and from Hunchungshi, Hadamen, China (strain CN2-186 T ). The isolates were Gram-stain-positive, non-motile, aerobic, rod-shaped bacteria. KR10-350 T was negative for oxidase and catalase activities, while oxidase-negative and catalase-positive activities were observed in CN2-186 T . KR10-350 T grew at temperatures ranging from 20 to 42 °C (optimum 30 °C), and a pH range of 5.0–8.5 (optimum 7.0), and grew only at NaCl concentrations of 0%. CN2-186 T grew at temperatures ranging from 10 to 37 °C (optimum 30 °C), at a pH range of 5.5–8.5 (optimum pH 7.0), and growth occurred at NaCl 0–0.5% concentrations (w/v; optimum, 0%). The 16S rRNA gene-based phylogenetic analysis revealed that strains KR10-350 T and CN2-186 T were closely related to members of the genus Nocardioides . The G + C content of strains KR10-350 T and CN2-186 T was 71.40 mol% and 70.70 mol%, respectively. The average nucleotide identity (ANI) values between strains KR10-350 T , CN2-186 T and the closely related Nocardioides type strains ranged from 74.66 to 83.15%, while the digital DNA–DNA hybridization (dDDH) values were within the range of 19.70–28.60%. The major fatty acids of strain KR10-350 T were iso C 16 : 0 , iso C 15 : 0 , anteiso C 17 : 0 and iso C 17 : 0 , whereas the major fatty acids of strain CN2-186 T were iso C 16 : 0 , C 18 : 1 ω9c and anteiso C 17:0 . For both strains, the major respiratory quinone was MK-8(H4), the major polar lipids included diphosphatidylglycerol, phosphatidylglycerol and phosphatidylcholine. Based on the dDDH, ANI, phylogenetic, biochemical and physiological analyses, it was indicated that strains KR10-350 T and CN2-186 T were distinct from other members of their genera. Thus, we proposed the names Nocardioides asiaticus sp. nov. (type strain KR10-350 T =KACC 23291 T =NBRC 116960 T ) and Nocardioides pollutisoli sp. nov. (type strain CN2-186 T =KACC 23446 T =CCTCC AA 2024106 T ).