Impact of Arsenic on the Environment and its Microbial Transformation


Edelweiss Airam Rangel Montoya1, Lilia E. Montañez Hernández1, Miriam P. Luévanos Escareño1 y Nagamani Balagurusamy*1

1 Lab. de Biorremediación de la Escuela de Ciencias Biológicas, Universidad Autónoma de Coahuila. Carretera Torreón-Matamoros km. 7.5. 27400 Torreón, Coahuila, México.


Arsenic is one of the most toxic metalloids found in nature, and speciation of arsenic depends on a diversity of chemical, physical and biological factors. Arsenic distribution and contamination on Earth is a consequence of many natural and anthropogenic processes, and is mainly due to its easy mobilization in the environment. High concentrations of arsenic in water and soil have become a global problem and long exposures to this metalloid can cause chronic damage to health, a particularly important problem in the Comarca Lagunera of Mexico. Therefore, it is important to look for new strategies for the efficient removal of arsenic. In this regard, microbial bioremediation offers an alternative environment friendly method to tackle this problem. Microorganisms play a major role in arsenic speciation since many of them have the capacity to transform it despite its toxicity. They have developed many different mechanisms such as oxido-reductions, enzymatic transformations, methylation, chelation and immobilization to utilize arsenic, in its reduced arsenite form or the oxidized arsentate form, in their metabolism. This study examines impact of arsenic speciation, especially As (III), on the environment and health as well as the biochemical mechanisms involved in the microbial oxidation of arsenite to reduce its toxicity, aiming to develop clean environment friendly strategies for removing arsenic from contaminated water and soil.