Streptomonospora halotolerans sp. nov., an actinomycete isolated from soil.

A novel actinomycete, designated strain NEAU-Jh2-17(T), was isolated from muddy soil collected from a riverbank in Jilin Province, northern China, and characterized using a polyphasic approach. The 16S rRNA gene sequence of strain NEAU-Jh2-17(T) showed highest similarity to those of Streptomonospora nanhaiensis 12A09(T) (99.26%), Nocardiopsis rosea YIM 90094(T) (97.31%), Streptomonospora halophila YIM 91355(T )(97.24%) and Streptomonospora arabica S186(T) (97.02%). Phylogenetic analysis based on 16S rRNA gene sequences demonstrated that strain NEAU-Jh2-17(T) fell within a cluster consisting of the type strains of species of the genus Streptomonospora and formed a stable clade with S. nanhaiensis 12A09(T) in trees generated with two algorithms. Key morphological and chemotaxonomic properties also confirmed the affiliation of strain NEAU-Jh2-17(T) to the genus Streptomonospora. The cell wall contained meso-diaminopimelic acid as the diagnostic diamino acid and whole-cell hydrolysates contained glucose, ribose and galactose. The polar lipids were diphosphatidylglycerol (DPG), phosphatidylethanolamine (PE), phosphatidylglycerol (PG), phosphatidylcholine (PC), phosphatidylinositol (PI), phosphatidylinositol mannoside (PIM), two unknown phospholipids (PLs) and two unknown glycolipids (GLs). The predominant menaquinones were MK-10(H2), MK-10(H8), MK-10(H6) and MK-10(H4). Major fatty acids were C18 : 0 10-methyl, anteiso-C17 : 0, C16 : 0 10-methyl, iso-C15 : 0, C17 : 0 10-methyl and C18 : 0. The DNA G+C content was 71.82 mol%. However, a combination of DNA-DNA hybridization results and some phenotypic characteristics demonstrated that strain NEAU-Jh2-17(T) could be distinguished from its closely related relatives. Therefore, strain NEAU-Jh2-17(T) is considered to represent a novel species of the genus Streptomonospora, for which the name Streptomonospora halotolerans sp. nov. is proposed. The type strain is NEAU-Jh2-17(T) ( = CGMCC 4.7218(T) = JCM 30347(T)).