Thermostaphylospora grisealba gen. nov., sp nov., isolated from mushroom compost and transfer of Thermomonospora chromogena Zhang et al. 1998 to Thermostaphylospora chromogena comb. nov.

A novel thermophilic actinomycete, designated strain 3-12X(T), was isolated from mushroom compost in Guangxi University, Nanning, China. The novel isolate contained meso-diaminopimelic acid as the diagnostic diamino acid and the whole-cell sugars were glucose and ribose. The predominant menaquinones were MK-9(H-4) and MK-9(H-6). The polar phospholipids were diphosphatidylglycerol, hydroxy-phosphatidylethanolamine, phosphatidylmethylethanolamine, phosphatidylethanolamine, phosphatidylinositol, phosphatidylinositol mannoside, ninhydrin-positive phosphoglycolipids and glycolipids. Major fatty acids were so-C-16 (: 0) and C-17 : 0. The G+C content of the genomic DNA was 74.6 %. The 16S rRNA gene sequence analysis showed that the closest phylogenetic neighbour of strain 3-12X(T) was Thermomonospora chromogena ATCC 43196(T) (97.0 %), other closely related strains all belonged to the family Streptosporangiaceae and showed more than 6% divergence. The chemotaxonomic characteristics of strain 3-12X(T) were significantly different from Thermomonospora chromogena ATCC 43196(T) and DNA-DNA hybridization showed low relatedness (48.6-55.6 %) between them, so they should be different species. Thermomonospora chromogena was removed from the genus Thermomonospora by Zhang et al. 1998 on the basis of phylogenetic, chemotaxonomic and phenotypic evidence, but its taxonomic position remains uncertain. Based on the phenotypic and phylogenetic data, strain 3-12X(T) represents a novel species in a new genus in the family Streptosporangiaceae. The name Thermostaphylospora griseoalba gen. nov., sp. nov. is proposed. The type strain of Thermostaphylospora grisealba is 3-12X(T) (=DSM 46781(T)=CGMCC 4.7160(T)). We also propose transferring Thermomonospora chromogena Zhang et al. 1998 to Thermostaphylospora chromogena comb. nov. (type strain ATCC 43196(T)=JCM 6244(T)).