Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/22/2007
Publication Date: 12/1/2007
Citation: Labeda, D.P., Kroppenstedt, R.M. 2007. Proposal for Umezawaea gen. nov., a new genus of the Actinosynnemataceae related to Saccharothrix and transfer of Saccharothrix tangerinus Kinoshita et al. 2000 as Umezawaea tangerina gen. nov., comb. nov. International Journal of Systematic and Evolutionary Microbiology. 57 (12):2758-2761. Interpretive Summary: The classification of microorganisms has been in a rapid state of change in recent years because of the advent of gene sequence-based molecular analyses of relationships at the genus or species level or higher. Taxonomic conclusions based on gene sequence data can be affected by the number of representative related sequences available for study and insufficient data can result in incorrect decisions. The original description of Saccharothrix tangerinus, the producer of the antifungal antibiotic formamicin, included data that could discriminate it from the genus Saccharothrix, but the molecular systematic analysis was based on 16S ribosomal RNA gene sequences from a relatively limited number of members of this genus and close relatives and thus a decision was made to place it into Saccharothrix. A recent analysis including the gene sequences for all members of the genus Saccharothrix as well as all of the other closely related microorganisms clearly showed that this microorganism represents a new genus which is well supported by the chemical composition and morphology of this strain. The name Umezawaea is formally proposed for this genus and the description of the morphological, physiological, and genetic characteristics of this new genus and species may assist researchers in biotechnology in isolating additional representatives of the genus for exploitation as a source of new antibiotics and other useful compounds.
Technical Abstract: In the course of phylogenetic analyses of the taxa within the suborder Pseudonocardineae, it was observed that Saccharothrix tangerinus MK27-91T was misplaced in the genus Saccharothrix. After a detailed examination of nucleotide signatures in the 16S rRNA gene sequence along with the morphological and chemotaxonomic characteristics of this strain, which are different from all species of Saccharothrix as well as the other genera within the suborder, it was concluded that this strain represents a new genus for which the name Umezawaea gen. nov. is proposed. Members of this genus produce pseudosporangia on the aerial mycelium, have a whole-cell sugar pattern consisting of galactose and rhamnose, phosphatidylethanolamine, diphosphatidyl glycerol, phosphatidylglycerol, phosphatidylinositol, phosphatidylinositol mannosides, and small quantities of phosphatidylethanolamine containing hydroxylated fatty acids are the predominant phospholipids, and MK-9(H4) as the predominant menaquinone with small quantities of MK-9(H2), MK-9(H6) and MK-10(H4) also present. The type species of the proposed new genus is Umezawaea tangerina comb. nov. and the type strain is NRRL B-24463T(=MK27-91FT=DSM 44720T =FERM P-16053T =IFO 10302T =JCM 10302T =NBRC 10302T).