Actinorhabdospora filicis gen. nov., sp. nov., a new member of the family Micromonosporaceae.

The actinomycete strains K12-0408T and K12-0792 were isolated on CM-cellulose agar from rhizosphere soil of a pteridophytic plant collected in Tokyo prefecture, Japan. Their taxonomic positions were determined using a polyphasic approach. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains K12-0408T and K12-0792 were positioned within the family Micromonosporaceae . The strains formed extensively branched aerial and substrate mycelia. Long chains of cylindrical spores with smooth surfaces were formed on aerial hyphae. The cell wall contained meso-diaminopimelic acid, and galactose, glucose, mannose and ribose were detected in whole-cell hydrolysates. The predominant menaquinones were MK-10(H4) and MK-10(H6). The major cellular fatty acids were anteiso-C17 : 0 and anteiso-C17 : 0 2-OH. The DNA G+C contents of strains K12-0408T and K12-0792 were 69.6 and 69.7 mol%, respectively. Based on data from the present polyphasic taxonomic study, strains K12-0408T and K12-0792 represent a novel genus, for which the name Actinorhabdospora gen. nov. is proposed, with strain K12-0408T (=NBRC 111897T=TBRC 5327T) as the type strain of the type species, Actinorhabdospora filicis sp. nov.