Submitted to: International Journal of Systematic and Evolutionary Microbiology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/2/2010
Publication Date: 6/20/2011
Publication URL: http://handle.nal.usda.gov/10113/60424
Citation: Labeda, D.P., Goodfellow, M., Chun, J., Zhi, X.Y., Li, W.J. 2011. Reassessment of the systematics of the suborder Pseudonocardineae: transfer of the genera within the family Actinosynnemataceae Labeda and Kroppenstedt 2000 emend. Zhi et al. 2009 into an emended family Pseudonocardiaceae Embley et al. 1989 emend. Zhi et al. 2009. International Journal of Systematic and Evolutionary Microbiology. 61(6)1259-1264. Interpretive Summary: In recent years an increasing number of actinobacterial species have been described and their 16S ribosomal RNA gene sequences made available in recent years because of intense research into the microbial diversity of soils and on plants in various parts of the world. Assessment of the grouping of microbial species at the family level through the inclusion of these new sequence data into phylogenetic analyses has shown that the proposal in 2000 for the family Actinosynnemataceae included one genus, Actinokineospora, that was incorrect. The description of this family is corrected to remove Actinokineospora and transfer it to the family Pseudonocardaceae, whose description is also updated. This change will have impact with researchers worldwide who are studying the higher level systematics of the class Actinobacteria and will also provide useful insights to biotechnology researchers searching for novel secondary metabolites, such as antibiotics, or enzymes.
Technical Abstract: The taxonomic status of the families Actinosynnemataceae and Pseudonocardiaceae was assessed based on the 16S rRNA sequence data available for the 152 valid taxa, as well as the chemotaxonomic and morphological properties available from the literature. The 16S rRNA gene sequences for the type strains of all taxa within the suborder Pseudonocardineae were subjected to phylogenetic analyses using different algorithms in ARB and MEGA. The phylogenetic position of the species of the genus Actinokineospora, currently designated as a member of the family Actinosynnemataceae, was observed to be distant from Actinosynnema, Lechevalieria, Lentzea, and Umezawaea, the other genera composing this family. The species of the genus Actinokineospora also contain arabinose in whole-cell hydrolysates, which is not observed in the other genera within the Actinosynnemataceae. This trait, however, is typical of the genera within the Pseudonocardiaceae that are phylogenetically nearest to Actinokineospora. The description of the family Actinosynnemataceae is emended to remove the genus Actinokineospora and this genus is now placed in the family Pseudonocardiaceae, whose description is emended to accommodate this genus.