An endophytic actinomycete, strain YIM 65070(T), was isolated from surface-sterilized tissue of Osyris wightiana Wall. ex Wight collected from Yunnan province, south-west China, and characterized by using a polyphasic approach. Strain YIM 65070(T) had morphological and chemotaxonomic markers that were consistent with its classification in the genus Herbidospora. Phylogenetic analysis based on almost complete 16S rRNA gene sequences indicated that strain YIM 65070(T) was phylogenetically very closely related to Herbidospora cretacea IFO 15474(T). DNA-DNA hybridization experiments confirmed the separate genomic status of strains YIM 65070(T) and H. cretacea DSM 44071(T). Moreover, strain YIM 65070(T) could be distinguished from H. cretacea DSM 44071(T) by differences in several phenotypic characteristics such as tolerance to NaCl, degradation activity, utilization of sole carbon and nitrogen sources and the cellular fatty acid contents. On the basis of phenotypic and phylogenetic evidence, strain YIM 65070(T) was identified as a novel species of the genus Herbidospora, for which the name Herbidospora osyris sp. nov. is proposed, with YIM 65070(T) (=CCTCC AA 208019(T)=DSM 45214(T)) as the type strain.

The taxonomic position of two actinomycete strains isolated from soil was studied. The isolates contained glutamic acid, alanine and meso-diaminopimelic acid as cell-wall amino acids and menaquinone MK-9(H4) and madurose in the whole-cell hydrolysate. Phylogenetic analysis revealed that the isolates belonged to the family Streptosporangiaceae, but not to any known genus, and formed a monophyletic cluster with Streptosporangium corrugatum. On the basis of morphological characteristics, phylogenetic analysis and DNA-DNA hybridization, the name Acrocarpospora gen. nov. is proposed for a new genus containing the isolates and Streptosporangium corrugatum, and Acrocarpospora pleiomorpha sp. nov. R-31T (= IFO 16267T), Acrocarpospora macrocephala sp. nov. R-55T (=IFO 16266T) and Acrocarpospora corrugata comb. nov. IFO 13972T are described.

Eight actinomycete strains originally isolated from soil and plant samples were studied to determine their taxonomic status. All isolates produced branching substrate mycelia, but no distinct aerial hyphae. Relatively short chains of nonmotile spores (10 to 30 spores per chain) were borne on the tips of sporophores arising directly from the agar surface. The chemotaxonomic characteristics of the isolates, with the exception of the menaquinone profile, coincided with those of members of the family Streptosporangiaceae Goodfellow, Stanton, Simpson, and Minnikin 1990. Furthermore, the results of a phylogenetic analysis performed with 5S rRNA support the conclusion that the isolates should be classified in this family. The isolates differed from members of the constituent genera of the Streptosporangiaceae in morphological characteristics and menaquinone composition. Therefore, we propose a new genus for the strains, Herbidospora. The type species and type strain are Herbidospora cretacea sp. nov. and strain K-319 (= JCM 8553), respectively.

An actinomycete strain, DMKUA 205(T), was isolated from a soil sample collected from the Sakaerat Biosphere Reserve in Nakhonratchasima Province, Thailand. The novel strain produced short chains of non-motile spores on the tips of long sporophores branching from the vegetative hyphae. The morphological and chemotaxonomic properties of this new isolate corresponded to those of members of the genus Herbidospora. Furthermore, 16S rRNA gene sequence analysis showed that the strain was closely related to members of the genus Herbidospora. Phenotypic properties and DNA-DNA relatedness values differentiated the new strain from its closest phylogenetic relatives Herbidospora yilanensis 0351M-12(T) (35-54 % DNA-DNA relatedness) and Herbidospora daliensis 0385M-1(T) (58-65 % relatedness). On the basis of phenotypic, genotypic and phylogenetic data, strain DMKUA 205(T) could be clearly distinguished from the type strains of H. yilanensis and H. daliensis. Therefore, strain DMKUA 205(T) represents a novel species, for which the name Herbidospora sakaeratensis sp. nov. is proposed. The type strain is strain DMKUA 205(T) (= BCC 11662(T) = NBRC 102641(T)). In addition, the DNA-DNA hybridization results from this study revealed that Streptosporangium claviforme is a later synonym of Herbidospora cretacea.