Sphingomonas horti sp. nov., a novel bacterial species isolated from soil of a tomato garden.

A novel bacterial strain, designated MAH-20, was isolated from a soil sample of a tomato garden. Cells of strain MAH-20 were Gram-stain negative, aerobic, motile, and rod-shaped. The colonies were light brown colored, smooth, spherical, and 0.2-0.7 mm in diameter when grown on Luria-Bertani agar for 2 days. Strain MAH-20 grows at 15-40 °C (optimum growth temperature 30-32 °C), at pH 5.0-10.0 (optimum growth pH 7.0) and at 0-2.0% NaCl. The strain showed positive activity for both oxidase and catalase tests. Cells were able to hydrolyze starch, DNA, urea, gelatin, L-arginine, and Tween 20. According to the 16S rRNA gene sequence similarity, the strain MAH-20 was identified as a new member of the genus Sphingomonas and had the close sequence similarity with Sphingomonas changbaiensis V2M44 (98.9%) and Sphingomonas tabacisoli X1-8 (98.1%). The genomic ANI value between strain MAH-20 and S. changbaiensis NBRC 104936 was 84.4%. The novel strain MAH-20 has a draft genome size of 3,350,026 bp (25 contigs), annotated with 3210 protein-coding genes, 46 tRNA, and 3 rRNA genes. The genomic DNA G + C content of isolate was 67.3 mol%, the predominant quinone was ubiquinone 10 and the major fatty acids were C, C ω6c and summed feature 8 (comprising C ω7c and/or C ω6c). On the basis of DNA-DNA hybridization results, phenotypic, genotypic, and chemotaxonomic data, the isolated strain MAH-20 represents a novel species, for which the name Sphingomonas horti sp. nov. is proposed, with MAH-20 as the type strain (= KACC 19746 = CGMCC1.13658).