Fig. 1From: Culture-based study on the development of antibiotic resistance in a biological wastewater system treating stepwise increasing doses of streptomycinNeighbor-joining phylogenetic tree showing the clustering of the 16S rRNA gene sequences of bacterial strains isolated from various STM exposures in biological reactors. The constructed tree was tested by the bootstrap method and bootstrap values are depicted adjacent to each node. The 0.02 scale bar indicates the nucleotide substitution levelBack to article page