PHYLOGENETIC ANALYSIS OF SACCHAROTHRIX AND RELATED TAXA: PROPOSAL FOR ACTINOSYNNEMACEAE FAM. NOV.

Authors: Labeda, David; KROPPENSTEDT, REINER - DSMZ-BRAUNSCHWEIG,GERMANY

Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/8/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary: The relationships of several relatively recently described groups of filamentous soil bacteria (actinomycetes), including species of Actinokineospora, Lentzea, and Saccharothrix, were not known. These microorganisms are of interest because many produce novel antibiotics of potential medical and agricultural importance. The relationships of these microorganisms to each other and other similar bacteria was studied by determining the sequence of their ribosomal RNA gene (genetic material) and comparing it with the sequences of this gene for the other members of these specific groups as well as the bacterial ribosomal RNA gene sequence information already in public databases. It was found that actinomycetes of the genera Actinokineospora, Actinosynnema, Kutzneria, Lentzea, Saccharothrix, and Streptoalloteichus are related based on the sequence of this gene and that this correlates very well with the similar chemical composition also observed for these microorganisms. It is proposed that a new family, to be named the Actinosynnemaceae, be created to contain all strains of these specific actinomycetes based on the chemical composition and gene sequence data. The gene sequence information deposited in public databanks and the knowledge of the significance of the specific chemical composition profile of this bacterial family should make it easier for other researchers studying the ecology of soil or searching for new antibiotics to discover and identify new strains of these microorganisms.

Technical Abstract: Partial sequences for 16S rDNA were determined for strains of the genus Saccharothrix, including most described species, as well as strains of the described species of the related genera Kutzneria, Actinokineospora, and Actinosynnema. These were aligned with published sequences for other species of these genera, as well as those of the genera Lentzea, Kutzneria, Streptoalloteichus, and representative taxa from other actinomycete families. Phylogenetic analysis of the sequence data showed that species of the genera Actinokineospora, Actinosynnema, Kutzneria, Lentzea, Saccharothrix, and Streptoalloteichus are members of the same clade, and distinct from the Pseudonocardiaceae. It is proposed that a new family be created within the class Actinobacteria for these genera, to be called the Actinosynnemaceae on the basis of the oldest described genus within this family, Actinosynnema Hasegawa et al. The chemotaxonomic properties of all the genera to be placed within the new family have similar cell wall type (Type III), whole cell sugars (generally galactose, mannose, and rhamnose), phospholipid type (PII), and menaquinones (MK- 9(H edominant).