RESUMO
An actinomycete strain, isolated from a Mata Atlântica soil sample, showing cellulolytic activity was subjected to polyphasic taxonomic characterization to determine its identity. Strain M7aT presented morphological and chemotaxonomic characteristics consistent with its assignment to the genus Streptomyces. Phylogenetic analysis of its 16S rDNA sequence revealed that the strain differed from described streptomycetes available in the public databases; the most closely related species was Streptomyces laceyi, with 98.4% nucleotide similarity. It also differed from other cellulolytic strains in its phenotypic characteristics. It is therefore proposed that strain M7aT, a cellulolytic strain with biotechnological potential, represents a novel species, named Streptomyces drozdowiczii sp. nov. The type strain is M7aT (=CBMAI 0498T=CIP 107837T=NRRL B-24297T).
Assuntos
Celulose/metabolismo , Microbiologia do Solo , Streptomyces/classificação , Streptomyces/isolamento & purificação , Aminoácidos/análise , Técnicas de Tipagem Bacteriana , Brasil , Parede Celular/química , DNA Bacteriano/química , DNA Ribossômico/química , Ácidos Graxos/análise , Genes de RNAr , Dados de Sequência Molecular , Filogenia , RNA Bacteriano/genética , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Homologia de Sequência , Streptomyces/citologia , Streptomyces/metabolismoRESUMO
Actinomycetes have been isolated from three Brazilian tropical soils. The dispersion and differential centrifugation procedure revealed count values 1.5 to 5.0 times greater than those obtained by the conventional dilution plate technique for all soils and media tested. Eighteen strains, promising for biotechnological applications, were submitted to chemotaxonomic procedures and numerical taxonomy for identification. Two were identified as Amycolatopsis orientalis, one as Streptomyces misakiensis, and two tentatively included or associated to S. chromofuscus and S. griseoruber. The others, all belonging to the Streptomyces genus, could not be fitted into any known species, and were arranged by the UPGMA analysis for classification, as an isolated group. This suggests that the actinomycetes in tropical soils may represent a vast unexplored resource for biotechnology.