RESUMO
A novel actinobacterium, designated strain 1AS2cT, was isolated from the wheat rhizosphere collected from the Brazilian Cerrado biome. A polyphasic approach, including phenotypic characterization and phylogenetic multilocus sequence analysis (MLSA), was used to determine the taxonomic position of this strain. Analysis of the 16S rRNA gene sequence indicated that the novel strain is closely related to Streptomyces cavourensis NBRC 13026T, Streptomyces albolongus NBRC 13465T and Streptomyces araujoniae ASBV-1T, sharing a similarity value of 98.2, 98.1 and 97.9â%, respectively. Additionally, MLSA of five housekeeping genes (atpD, gyrB, recA, rpoB and trpB) showed evolutionary distances beyond the 0.007 threshold, as well as low DNA-DNA relatedness between strain 1AS2cT and its closest phylogenetic neighbours (S. cavourensis NBRC 13026T, S. albolongus NBRC 13465T and S. araujoniae ASBV-1T: 56, 62.5 and 63.0â%, respectively), indicating a new phylogenetic lineage. The phylogenetic, chemotaxonomic and phenotypic characteristics support the assignment of strain 1AS2cT to the genus Streptomyces, representing a novel species. It is concluded that strain 1AS2cT (=CMAA 1679T=NRRL B-65479T=DSM 105299T) can be classified as the type strain of a novel species of the genus Streptomyces, for which the name Streptomyces rhizosphaericola sp. nov. is proposed.
Assuntos
Filogenia , Rizosfera , Microbiologia do Solo , Streptomyces/classificação , Triticum/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , Brasil , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Tipagem de Sequências Multilocus , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Streptomyces/isolamento & purificaçãoRESUMO
The taxonomic position of a streptomycete isolated from a potato tubercle was determined by using a polyphasic approach. The organism had chemotaxonomic and morphological properties consistent with its classification in the genus Streptomyces and formed a distinct phyletic line in the Streptomyces 16S rRNA gene tree. It was found to be closely related to Streptomyces celluloflavus NRRL B-2493(T) (99.4 % 16S rRNA gene similarity) and shared a 99.0 % 16S rRNA gene similarity value with Streptomyces albolongus NRRL B-3604(T) and Streptomyces cavourensis subsp. cavourensis NBRC 13026(T); low levels of DNA-DNA relatedness with these organisms showed that the isolate belonged to a distinct genomic species. The isolate was distinguished readily from the type strains of these species using a combination of morphological and other phenotypic properties. On the basis of these results, it is proposed that isolate ASBV-1(T) (= CBMAI 1465(T) = CCMA 894(T) = NRRL B-24922(T)) be classified as the type strain of Streptomyces araujoniae sp. nov.