Isolation and identification of arsenic-transforming bacteria from arsenic contaminated sites in Bulgaria

Five environmental sites in Bulgaria were sampled for bacterial isolates that could transform different arsenic forms. In total, 108 bacterial strains that could grow in the presence of high concentrations of arsenic species were isolated Only 2 7 from all strains show the transforming abilities. These isolates were enriched from the sediment samples, the perfomied classical taxonomy and analysis of the 16S rDNA gene sequence revealed them to belong to beta- and gamma-Proteobacteria and in particular in genera Pseudomonas, Azoarcus and Alcaligenes.