Humicoccus flavidus gen. nov., sp. nov., isolated from soil

Abstract

A Gram-positive, non-motile, spherical, non-spore-forming bacterial strain, DS-52(T), was isolated from soil from Dokdo, Korea, and its taxonomic position was investigated by using a polyphasic approach. It grew optimally at 25 degrees C and pH 6.0-7.0. Strain DS-52(T) had meso-diaminopimelic acid as the diagnostic diamino acid in the cell-wall peptidoglycan, and galactose, mannose, xylose and rhamnose as whole-cell sugars. It contained MK-8(H(4)) and MK-9(H(4)) as the predominant menaquinones and anteiso-C(15 : 0), iso-C(15 : 0) and C(17 : 0) as major fatty acids. Major polar lipids were diphosphatidylglycerol, phosphatidylethanolamine and phosphatidyldimethylethanolamine. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain DS-52(T) is most closely related to the genus Nakamurella of the suborder Frankineae. Strain DS-52(T) exhibited 16S rRNA gene sequence similarity values of 96.5 % to Nakamurella multipartita JCM 9543(T) and 92.0-93.9 % to other members of the suborder Frankineae. The diagnostic diamino acid type and polar lipid profile of strain DS-52(T) were the same as those of the genus Nakamurella. However, strain DS-52(T) could be clearly distinguished from the genus Nakamurella by differences in predominant menaquinones, major fatty acids and cell-wall sugars. Accordingly, based on combined phenotypic, chemotaxonomic and phylogenetic data, strain DS-52(T) (=KCTC 19127(T)=CIP 108919(T)) is proposed as the type strain of a novel species in a new genus, Humicoccus flavidus gen. nov., sp. nov.