Evaluation of gyrB sequences for taxonomic analyses of heavy metal resistant actinomycetes

ALBARRACÍN, VIRGINIA; POLTI, MARTA ALEJANDRA; AMOROSO, MARÍA JULIA; ABATE; CARLOS MAURICIO

Rosario

Congreso; XLII Reunión Anual SAIB; 2006

SAIB

Actinomycetes are Gram-positive bacteria whit high G+C content. 16S rDNA sequences analysis is a simple and commonly used method for identification of microorganisms, but in the last years it was demonstrated that gyrB gene sequences may be also applied to perform phylogenetic analyses of Streptomyces and other actinobacteria. In this work it was evaluated the use of gyrB sequences for taxonomic analyses of heavy metal resistant actinomycetes and the obtained results were compared with the 16S rDNA procedure. Total gDNA of heavy metal resistant actinomycete strains was amplified using 16S universal and gyrB specific primers. DNA and closely related specie sequences from public databases were aligned and compared; while phylogenetic trees were constructed by the neighbor-joining method. According to 16S rDNA analysis ten strains belonged to the Streptomyces genus and two to Amycolatopsis. gyrB gene sequences characterize the same ten strains as Streptomyces but failure to identify the Amycolatopsis genus. In addition, trees constructed with the related species from public databases were different depending on the taxonomic marker used. We conclude that the gyrB public database is still incomplete for Streptomyces and has not been developed yet to Amycolatopsis. This work contributes to construct a database of gyrB sequences to re-classificate Streptomyces and Amycolatopsis species.