Catenuloplanes crispus (Petrolini et al. 1993) comb. nov.: incorporation of the genus Planopolyspora Petrolini 1993 into the genus Catenuloplanes Yokota et al. 1993 with an amended description of the genus Catenuloplanes.

The taxonomic position of the genus Planopolyspora comprising a single species, Planopolyspora crispa, was reviewed. This genus was originally characterized by formation of long, curly and sometimes branching sporangia containing numerous zoospores arranged in a single row and by the presence of meso-diaminopimelic acid and madurose (3-O-methyl-D-galactose) in whole-cell hydrolysates. However, our chemotaxonomic analyses of the type strain of P. crispa did not agree with the original description. The peptidoglycan contained L-lysine but not meso-diaminopimelic acid, and the whole-cell hydrolysate contained xylose as the characteristic sugar but not madurose. These characteristics and other chemotaxonomic profiles (e.g. menaquinone, phospholipid and cellular fatty acid compositions) of the genus Planopolyspora coincided with those of the genus Catenuloplanes. These two genera also had very similar morphological characteristics, but in the original description of the genus Catenuloplanes the presence of sporangia was not referred to. This difference is considered to originate from a divergence of views owing to the ambiguity of the definition of the term 'sporangium' in actinomycete morphology. Phylogenetic analysis based on 16S rDNA sequences also supported the proposal that the genera Planopolyspora and Catenuloplanes should be combined into one genus. Levels of DNA relatedness among the type strains of P. crispa and six Catenuloplanes species and their cultural, physiological and biochemical characteristics indicated that P. crispa should be classified as an independent species of the genus Catenuloplanes, which has priority over the genus Planopolyspora. Therefore, it is proposed that Planopolyspora crispa be transferred to the genus Catenuloplanes as Catenuloplanes crispus comb. nov.