General Information: Herminiimonas arsenicoxydans was isolated from heavy metal contaminated sludge from an industrial water treatment plant. This organism has a number of mechanisms for metabolizing arsenic allowing it to effectively colonize arsenic-contaminated environments. A bacterium capable of oxidizing and reducing arsenic. This heterotrophic bacterium is capable of reducing and oxidizing arsenic with the objective of detoxification. Arsenic is both a product from natural sources and of human activities, and is widely distributed in the environment, essentially in 3 different oxidation states: As (-III) (arsine), As (+III) (arsenite) and As (+V) (arseniate). The ecology of this metalloid is strongly dependent on microbial transformations which affect the mobility and bioavailability as well as the toxicity of arsenic in the environment.