Streptacidiphilus anmyonensis sp. nov., Streptacidiphilus rugosus sp. nov. and Streptacidiphilus melanogenes sp. nov., acidophilic actinobacteria isolated from Pinus soils.

The taxonomic positions of 22 spore-forming, extensively branched actinobacteria isolated from Pinus soils were examined using a polyphasic approach. Analysis of the 16S rRNA gene sequences indicated that all of the isolates fell into three distinctive phylogenetic clusters within the genus Streptacidiphilus of the family Streptomycetaceae, and also that Streptacidiphilus jiangxiensis was the species closest to the three phyloclusters, with 16S rRNA gene sequence similarities ranging from 98.0 to 99.2 %. However, the low DNA-DNA relatedness values between representatives of the three clusters and S. jiangxiensis clearly differentiated them from one another. Representative isolates were also found to have chemotaxonomic features typical of the genus Streptacidiphilus and were distinguishable from all established species of Streptacidiphilus on the basis of a combination of phenotypic properties. It is evident from this study that each of the three phyloclusters should be equated with three novel Streptacidiphilus species, for which the following names are proposed: Streptacidiphilus anmyonensis sp. nov. (type strain AM11(T) =NBRC 103185(T) =KCTC 19278(T)), Streptacidiphilus rugosus sp. nov. (type strain AM16(T) =NBRC 103186(T) =KCTC 19279(T)) and Streptacidiphilus melanogenes sp. nov. (type strain SB-B34(T) =NBRC 103184(T) =KCTC 19280(T)).