Resumo

Members of the Actinobacteria class have considerable value as prolific producers of biologically active secondary metabolites and marine actinomycetes have yielded numerous novel secondary metabolites and new actinomycete taxa of marine origin have also been recovered. The genus Williamsia encompasses eight (8) recognized species isolated from diversity of environments, such as human blood, soil, meadow hay, deep-sea, sediment, indoor building materials, leaf surface and lake sediment. Multilocus Sequence Analysis (MLSA) has been considered an important and more accessible tool for assessing phylogeny and taxonomy of prokaryotes, increasing the inference obtained by phylogenetic analysis of 16S ribosomal RNA gene. Studies have shown that the comparison of multiple genes sequences that encode proteins is useful for the delineation of species and could take the place of DNA-DNA hybridization (DDH) required to define a new species. The purpose of this work was to report the polyphasic taxonomy study of three Williamsia isolates, obtained from marine macroorganism, collected from north coast of São Paulo State, Brazil, based on the analysis of 16S rRNA genes and evaluation the potential of MLSA (recA, rpoA, rpoB, trpB and gyrB genes) for taxonomy and classification of strains and comparison with DDH data. Genes were amplified by PCR and phylogenetic trees based on the single and concatenated 16S rRNA and housekeeping gene sequences were constructed and DDH was performed by fluorimetric method. Each single-gene tree had an overall topology similar to that of the concatenated sequence tree. All genes used in this study proved to be good molecular markers, were well consistent with the 16S rRNA gene analysis. High correlation between MLSA and DDH was observed, in both single and concatenated sequence phylogeny, showing good relation between the techniques.