Phylogenetic study of the species within the family Streptomycetaceae

Abstract

Species of the genus Streptomyces, which constitute the vast majority of taxa within the family Streptomycetaceae, are a predominant component of the microbial population in soils throughout the world and have been the subject of extensive isolation and screening efforts over the years because they are a major source of commercially and medically important secondary metabolites. Taxonomic characterization of Streptomyces strains has been a challenge due to the large number of described species, greater than any other microbial genus, resulting from academic and industrial activities. The methods used for characterization have evolved through several phases over the years from those based largely on morphological observations, to subsequent classifications based on numerical taxonomic analyses of standardized sets of phenotypic characters and, most recently, to the use of molecular phylogenetic analyses of gene sequences. The present phylogenetic study examines almost all described species (615 taxa) within the family Streptomycetaceae based on 16S rRNA gene sequences and illustrates the species diversity within this family, which is observed to contain 130 statistically supported clades, as well as many unsupported and single member clusters. Many of the observed clades are consistent with earlier morphological and numerical taxonomic studies, but it is apparent that insufficient variation is present in the 16S rRNA gene sequence within the species of this family to permit bootstrap-supported resolution of relationships between many of the individual clusters.

Streptomyces polygonati sp. nov., an endophytic actinomycete isolated from a root of Polygonatum odoratum (Mill.)

“…The DNA-DNA reassociation values were 41.5¡0.7 % and 12.1¡1.1 %, respectively, which were below the threshold value of 70 % recommended by Wayne et al (1987) for assigning strains to the same species. Labeda et al (2012) considered that a combination of 16S rRNA gene sequence and phenotypic data, notably standard cultural and morphological properties, provided a reliable means of assigning novel species to the genus Streptomyces. Therefore, a comparative study, which revealed that strain NEAU-G9 T differed from its closest relative S. yanglinensis JCM 13275 T and phylogenetically closest neighbour S. misakiensis JCM 4062 T in morphological, physiological and biochemical characteristics, was performed.…”

The use of morphological and cell wall chemical markers in the identification of <i>Streptomyces</i> species associated with Actinomycetoma

“…They form an integral part of soil microbial communities and making up approximately 10% of total soil microbial flora (8). The majority of research focused on the classification of these saprophytic strains (9,10), albeit the genus contains few human and plant pathogens (4,11). Streptomyces species are causal agents of diseases in man (S. somaliensis and S. sudanesnsis); animals (Streptomyces species) and plants (Streptomyces scabies) (6,12,13).…”

Streptomyces yangpuensis sp. nov., isolated from soil

“…The genus Streptomyces consisting of Gram-positive filamentous bacteria belongs to the class Actinobacteria. Members of the genus Streptomyces have a wide range of metabolic abilities and produce numerous enzymes and chemical compounds, including antibiotics, enzyme inhibitors, vitamins, antitumour agents and antifungal compounds (Goodfellow & Fiedler, 2010;Labeda et al, 2012). Many studies have focused on Streptomyces, which is the largest genus in the domain Bacteria, and at the time of writing, contains more than 690 species and subspecies with validly published names (Munoz et al, 2011;Parte, 2014;Quast et al, 2013).…”