Actinoplanes subglobosus sp. nov., isolated from mixed deciduous forest soil.

Abstract

A novel filamentous bacterial strain, A-T 5400T, which developed subglobose sporangia at the end of sporangiophores on substrate mycelia, was isolated from mixed deciduous forest soil collected in Thailand. The taxonomic position of this micro-organism was described using a polyphasic approach. The 16S rRNA gene sequence and phylogenetic analysis indicated that strain A-T 5400T belonged to the genus Actinoplanes and was most closely related to 'Actinoplanes hulinensis' NEAU-M9 (98.82 % 16S rRNA gene sequence similarity) and Actinoplanes philippinensis NBRC 13878T (98.75 %). The DNA-DNA relatedness values that distinguished the novel strain from the closest species were below 70 %. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars were ribose, galactose, glucose and xylose. The predominant menaquinone was MK-9(H4). The diagnostic phospholipids were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol. The predominant cellular fatty acids were unsaturated fatty acids C16 : 1, branched fatty acids iso-C16 : 0 and iso-C15 : 0. The G+C content of the genomic DNA was 71 mol%. Following evidence from phenotypic, chemotaxonomic and genotypic studies, the new isolate is proposed to represent a novel species of the genus Actinoplanes named Actinoplanes subglobosus sp. nov. The type strain is A-T 5400T (=BCC 42734T=TBRC 5832T=NBRC 109645T).