Union of the genera Actinoplanes couch, Ampullariella couch, and Amorphosporangium couch in a redefined genus Actinoplanes

DNA pairing experiments, rRNA cistron similarity studies and 16S rRNA oligonucleotide cataloguing show members of all three genera, including the type strains, to be closely related, forming a distinct cluster within the phylogenetic tree of the sporoactinomycetes.

Abstract

Except for differences in the morphology of sporangia and spores, members of the genera Actinoplanes, Ampullariella and Amorphosporangium can hardly be distinguished from each other by chemotaxonomic properties, e. g. whole cell sugars, phospholipids, fatty acids, menaquinones and peptidoglycan type. These obvious similarities at the phenotypic level, known for two decades, could recently be extended to the genetic level. DNA pairing experiments, rRNA cistron similarity studies and 16S rRNA oligonucleotide cataloguing show members of all three genera, including the type strains, to be closely related, forming a distinct cluster within the phylogenetic tree of the sporoactinomycetes. The high genetic and phenotypic similarity of these organisms support their union into one genus Actinoplanes for which an emended description is given.