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

ABSTRACT

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, Actinorhabdosporafilicis sp. nov.