Global genomic expression of active bacteria populations that transform arsenic in sediments of Salar de Ascotan, Chile

摘要

Arsenic mobility and bioavailability in sediment can be controlled by microbial mediated transformations between the most prevalent types of dissolved arsenic: arsenite and arsenate. Specialist bacteria able to obtain energy for growth through redox transformations of arsenic have been evidenced in Salar de Ascotan, Antofagasta region, Chile. The global genomic expression has been analyzed by RAP-PCR using arbitrary primers, to detect microorganisms with active metabolism in Laguna Turquesa. Several protein sequences revealed that many genes related to arsenic resistance have been expressed in this environment: arsM gene, responsible for the removal of arsenic as the volatile arsines: MraW protein, hpmolog also with ArsM protein; acetyl-CoA acetyltransferase, which present similarity with a novel arsenate resistance gene, arsN. Our results suggest that novel bacteria with important biotechnological properties could be exploited in this unique and stressed saline environment.