RESUMO
Two motile actinomycetes, designated strains 03-723(T) and 03-8772(T), which had potent inhibitory activity against Enterococcus faecium peptide deformylase and several clinical Gram-positive, antibiotic-resistant strains, were isolated from two soil samples collected from Sichuan Province and Xinjiang Uyghur Autonomous Region in China, respectively. The taxonomic status of these two organisms was established by using a polyphasic approach. The taxonomic data were consistent with the assignment of the strains to the genus Actinoplanes. The neighbour-joining phylogenetic tree based on 16S rRNA gene sequences showed that the two isolates formed a branch with the type strains of Actinoplanes lobatus, Actinoplanes auranticolor, Actinoplanes capillaceus, Actinoplanes campanulatus and Actinoplanes philippinensis in the clade of Actinoplanes species. This branching pattern was also supported by the tree constructed with the maximum-parsimony method. Levels of 16S rRNA gene sequence similarity between strains 03-723(T) and 03-8772(T) and their phylogenetic neighbours ranged from 98.0 to 98.8 % and 97.4 to 98.1 %, respectively. However, the two strains shared low levels of DNA-DNA relatedness with the type strains of closely related Actinoplanes species and were readily distinguished by using a combination of phenotypic properties. Therefore, it is proposed that strains 03-723(T) and 03-8772(T) represent two novel species of the genus Actinoplanes, for which the names Actinoplanes sichuanensis sp. nov. (type strain 03-723(T)=KCTC 19460(T)=CCM 7526(T)) and Actinoplanes xinjiangensis sp. nov. (type strain 03-8772(T)=KCTC 19461(T)=CCM 7527(T)) are proposed.
