Arsenic in water wells in Tucumán, Argentina: Bacterial community analysis and resistance genes screening

Abstract

Arsenic is a toxic metalloid present in a variety of environments. It can be released by either natural weathering of rocks or by anthropogenic activities. Arsenic is found in the oxidation states +5 (arsenate), +3 (arsenite), 0 (elemental arsenic), and -3 (arsine). Contamination of drinking water supplies with inorganic soluble forms, arsenite and arsenate, has often been reported, thus arsenic has been identified as a major risk for human health in different parts of the world. The biogeochemical cycle of this element strongly depends on microbial transformation, which affects the mobility and distribution of arsenic species in the environment. Several bacteria involved in transformation processes comprising reduction, oxidation and methylation of arsenic species have been previously described.