Humibacter soli sp. nov., isolated from soil.

Abstract

A novel actinobacterial strain, designated R1-20T, was isolated during a study of the bacterial diversity of the soil at a white heron nesting site. The isolate was non-motile, Gram-stain-positive and short rod-shaped. Colonies were dull white and convex with entire margin during the early stages of growth, and gradually became yellow. 16S rRNA gene sequence analysis indicated that the isolate belongs to the genus Humibacter of the family Microbacteriaceae, as sequence similarity with its nearest neighbours was 97.16 % with Humibacter antriD7-27Tand 96.44 % with Humibacter albusDSM 18994T. However, the combination of cultural and physiological as well as chemotaxonomic properties clearly distinguished strain R1-20T from other Humibacter species. The DNA G+C content of strain R1-20T was 65.5 mol%, and the major respiratory isoprenoid quinone was menaquinone MK-11. The acyl group of the peptidoglycan was of acetyl type, and the diagnostic diamino acid was 2,4-diaminobutyric acid. Glutamic acid, alanine and glycine were also present in the cell wall. The major fatty acids of strain R1-20T were anteiso-C17 : 0, iso-C16 : 0 and anteiso-C15 : 0. On the basis of phylogenetic, phenotypic and chemotaxonomic analysis, strain R1-20T merits recognition as a representative of a novel species of the genus Humibacter, for which the name Humibacter soli sp. nov. is proposed. The type strain is R1-20T (=KCTC 39614T=JCM 31015T).