Isolation of native arsenic bacteria from gold mine and evaluation of their tolerance

ABSTRACT: Although the arsenic element is toxic for the life, various types of microorganisms are able to gain energy for growth from this toxic element. The aim of the present study was to isolate native arsenic bacteria from gold mine and then evaluate their tolerance. In this study four strains of bacteria were isolated from the soil of Takabgold mine. These isolates were identified at genus level. They were belonged to these genera: Bacillus, Staphilococcus, Dienococcus and Roseomonas. The later one was able to grow in 2 ppm of arsenic. The results of this study showed that Roseomonas strain could not tolerate up to 3 ppm of gold in the presence of 2 ppm arsenic, while when Roseomonas strain was cultured in the medium without arsenic it was able to grow in 3 ppm of gold. In the other word the amount of arsenic impress on the gold tolerance of bacteria. Isolation of bacteria and evaluation of using arsenic in them is ongoing because these bacteria can used to help remove arsenic pollution such as remove arsenic from water.