Sphingomonas chungangi sp. nov., a bacterium isolated from garden soil sample

Abstract

A novel bacterial strain, designated MAH-6T, was isolated from a garden soil sample. Cells were Gram-stain-negative, aerobic, non-motile and rod-shaped. The colonies were light yellow, smooth, circular and 0.6-1.2 mm in diameter when grown on nutrient agar for 3 days. Strain MAH-6T grew at 15-35 °C, at pH 5.0-7.0 and with 0-0.5 % NaCl. Cell growth occurred on nutrient agar and Reasoner's 2A (R2A) agar. The strain was positive for both catalase and oxidase tests. Cells were able to hydrolyse starch, aesculin, Tween 20 and Tween 80. According to 16S rRNA gene sequence comparisons, the isolate was identified as a member of the genus Sphingomonas and was most closely related to Sphingomonas polyaromaticivorans B2-7T (98.2 % sequence similarity), Sphingomonas oligoaromativorans SY-6T (96.9 %) and Sphingomonas morindae NBD5T (96.6 %). The novel strain MAH-6T has a draft genome size of 4 370 740 bp (28 contigs), annotated with 4199 protein-coding genes, 46 tRNA and three rRNA genes. The genomic DNA G+C content of the strain was determined to be 66.2 mol% and the predominant isoprenoid quinone is Q-10. The major fatty acids were identified as summed feature 8 (comprising C18 : 1 ω7c and/or C18 : 1 ω6c), C14 : 0 2OH and C16 : 0. The main polar lipids were phosphatidylcholine, sphingoglycolipid, phosphatidylethanolamine, phosphatidylglycerol and diphosphatidylglycerol. Based on the results of phenotypic, genotypic, chemotaxonomic and DNA-DNA hybridization studies, strain MAH-6T represents a novel species, for which the name Sphingomonas chungangi sp. nov. is proposed, with MAH-6T as the type strain (=KACC 19292T=CGMCC1.13654T).