Spirosoma sordidisoli sp. nov., a propanil-degrading bacterium isolated from a herbicide-contaminated soil

A novel Gram-stain negative, aerobic, rod-shaped, asporogenous, propanil-degrading bacterial strain, TY50^T, was isolated from a herbicide-contaminated soil in Nanjing, China. Strain TY50^T was found to grow optimally at pH 9.0, 30 °C and in the absence of NaCl. The G + C content of the total DNA was determined to be 55.5 mol%. The 16S rRNA gene sequence of strain TY50^T shows high identity to that of Spirosoma lacussanchae CPCC 100624^T (99.3%), Spirosoma metallicum PR1014k^T (94.8%) and Spirosoma soli MIMBbqt12^T (94.6%). DNA-DNA hybridization indicated that the isolate had relatively low levels of DNA-DNA relatedness with S. lacussanchae CPCC 100624^T (48.3%). Average nucleotide identity and the digital DNA-DNA hybridizations for draft genomes between strain TY50^T and S. lacussanchae CPCC 100624^T were 93.2% and 51.0%, respectively. The major cellular fatty acids of strain TY50^T were identified as C_16:1ω5c (24.5%) and summed feature 3 (C_16:1ω6c/C_16:1ω7c, 40.7%). MK-7 was found to be the predominant respiratory quinone. The major polar lipid profile includes phosphatidylethanolamine, an unidentified lipid and an unidentified aminolipid. These chemotaxonomic data support the affiliation of strain TY50^T with the members of the genus Spirosoma. Strain TY50^T can be distinguished from its close phylogenetic neighbours based on its phenotypic, genotypic, and chemotaxonomic features. Therefore, strain TY50^T represents a novel member of the genus Spirosoma, for which the name Spirosoma sordidisoli sp. nov. is proposed. The type strain is TY50^T (= KCTC 62494^T = CCTCC AB 2018041^T).