Planobispora siamensis sp. nov., isolated from soil.

A novel actinomycete strain, A-T 4600T, which developed cylindrical sporangia containing a longitudinal pair of motile spores forming singly or in bundles on short ramifications of the aerial mycelium, was isolated from soil collected from an evergreen forest in Thailand. The cell-wall peptidoglycan contained meso-diaminopimelic acid. The whole-cell sugars contained ribose, madurose, mannose and glucose. The predominant menaquinones were MK-9(H2). Mycolic acids were not detected. The diagnostic phospholipids were phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylinositol, phosphatidylglycerol, phosphatidylinositol mannoside, diphosphatidylglycerol and aminophosphoglycolipid. The predominant cellular fatty acids were unsaturated C17 : 1, C18 : 1, saturated C16 : 0, and C17 : 0. The G+C content of the DNA was 70.8 mol%. Phenotypic and chemotaxonomic analyses showed that the isolate had the typical characteristics of members of the genus Planobispora . Furthermore, 16S rRNA gene sequence analysis also indicated that this strain belonged to the genus Planobispora but as a putative novel species. DNA–DNA relatedness values that differentiate the isolate from previously described members of the genus Planobispora were significantly below 70 %. Following an evaluation of phenotypic, chemotaxonomic and genotypic studies, it is proposed that the isolate represents a novel species, Planobispora siamensis sp. nov.; the type strain is A-T 4600T ( = BCC 39469T = NBRC 107568T).