Sphingosinicella humi sp. nov., isolated from arsenic-contaminated farmland soil and emended description of the genus Sphingosinicella

A Gram-stain-negative, strictly aerobic bacterium, designated strain QZX222T, was isolated from arsenic-contaminated farmland soil. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain QZX222T was clustered with Sphingosinicella vermicomposti YC7378T (97.0 %), Sphingosinicella xenopeptidilytica 3–2W4T (96.1 %), Sphingosinicella microcystinivorans Y2T (96.0 %) and Sphingosinicella soli KSL-125T (95.9 %). Compared to strain QZX222T, Spingomonas olgophenolica JCM 12082T and Sphingobium boeckii 469T had 16S rRNA gene similarities of 96.2 and 95.9 %, respectively, but they located in other phylogenetic clusters. DNA–DNA hybridization and genomic ANI values between strain QZX222T and Sphingosinicella vermicomposti DSM 21593T (KCTC 22446T) were 34.8 and 75.0 %, respectively. The genome size of strain QZX222T was 3.0 Mb including 2982 predicted genes. The strain had a DNA G+C content of 65.9 mol%. Strain QZX222T had ubiquinone Q-10 as the major respiratory quinone and homospermidine as the major polyamine. The major fatty acids (>10 %) of strain QZX222T were C17 : 1 ω6c, summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c) and C17 : 1 ω8c. The polar lipids were sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylcholine and an unidentified glycolipid. Strain QZX222T could be distinguished from other Sphingosinicella strains based on the results of phylogenetic and genomic analyses, DNA–DNA hybridization, white colour colony, hydrolysis of urea, alkaline phosphatase activity, lack of phosphatidylmonomethylethanolamine, and presence of phosphatidylcholine. Therefore, strain QZX222T represents a novel species of Sphingosinicella , for which the name Sphingosinicella humi sp. nov. is proposed. The type strain is QZX222T (=KCTC 62519T=CCTCC AB 2018030T).