Sphingomonas segetis sp. nov., isolated from spinach farming field soil

A Gram-stain-negative bacterium, designated strain YJ09 T , was isolated from spinach farming field soil at Shinan in the Republic of Korea. Cells of strain YJ09 T were found to be strictly aerobic, non-motile, non-spore-forming creamy-yellow rods which can grow at 20–37 °C (optimum, 30 °C), at pH 6.0–9.0 (optimum, pH 7.0–8.0) and at salinities of 0–0.5 % (w/v) NaCl (optimum, 0 % NaCl). The 16S rRNA gene sequence analysis showed that strain YJ09 T belongs to the genus Sphingomonas with high sequence similarities to Sphingomonas parvus GP20-2 T (98.0 %), Sphingomonas agri HKS-06 T (97.7 %) and Sphingomonas lutea JS5 T (97.4 %). The results of phylogenetic analysis indicated that strain YJ09 T formed a distinct phyletic line in the genus Sphingomonas and the results of DNA–DNA relatedness studies demonstrated that strain YJ09 T could be separated from its closest relatives in the genus Sphingomonas . The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, unidentified glycolipids, an unidentified phospholipid and sphingoglycolipid. The predominant ubiquinone and polyamine components were Q-10 and spermidine, respectively. The major fatty acids were C 18:1 ω7 c, C 16 : 0 and C 16:1 ω7 c and/or iso-C 15 : 0 2-OH. The DNA G+C content of this novel isolate was 65.9 mol%. On the basis of phenotypic, chemotaxonomic properties and phylogenetic analyses in this study, strain YJ09 T is considered to represent a novel species in the genus Sphingomonas , for which the name Sphingomonas segetis sp. nov. is proposed. The type strain is YJ09 T (=KACC 19551 T =NBRC 113247 T ).