Saccharopolyspora rhizosphaerae sp. nov., an actinomycete isolated from rhizosphere soil in Thailand

A novel actinomycete, designated as strain H219(T) was isolated from rhizosphere soil collected under an Elephant ear plant (Colocasiaesculenta) in Bangkok, Thailand. Strain H219(T) was characterised using a polyphasic approach. Phylogenetic analysis of the 16S rRNA gene sequences revealed that this isolate was most closely related to Saccharopolyspora tripterygii JCM 32123(T) (97.6 %), Saccharopolyspora dendranthemae NBRC 108675(T) (97.5 %) and Saccharopolyspora flava NBRC 16345(T) (97.5 %). However, DNA-DNA hybridization analyses showed a low relatedness in the range of 39-48 % between the novel isolate and the above closely related strains. The cell-wall peptidoglycan of strain H219(T) contained meso-diaminopimelic acid. The diagnostic whole-cell sugars consisted of arabinose and galactose. The cellular fatty acid profile mainly comprised iso-C-16:0, anteiso-C-17:0, iso-C-15:0, and 10-methyl C-17:0. The major menaquinone was MK-9(H-4). The detected phospholipids were diphosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, phosphatidylethanolamine-containing hydroxylated fatty acids and an unknown phospholipid. The DNA G+C content was 70.6 mol%. Strain H219(T) represented chemotaxonomic and morphological characteristics that were consistent with members of the genus Saccharopolyspora. However, strain H219(T) could be distinguished from closely related strains by several phenotypic properties. Based on the data from the polyphasic studies, we propose that strain H219(T) is a novel species within the genus Saccharopolyspora, Saccharopolyspora rhizosphaerae sp. nov. The type strain is H219(T) (=TBRC 8564(T)=NBRC 113388(T)).