Water Resources Research Act Program

Details for Project ID 2008NJ161B

Microbial Mobilization of Arsenic and Selenium Oxyanions in Subsurface Aquifers

Institute: New Jersey
Year Established: 2008 Start Date: 2008-03-01 End Date: 2009-02-28
Total Federal Funds: $5,000 Total Non-Federal Funds: $13,038

Principal Investigators: Ines Rauschenbach, Max Haggblom

Project Summary: Arsenic (As) and selenium (Se) toxicity and their ever-increasing contamination of groundwater and soil has become a global concern threatening the lives of tens of millions of people. The soluble forms selenate (Se(VI)) and selenite (Se(IV)) are the primary forms of selenium in oxic environments and both are toxic. Elemental, water-insoluble selenium (Se(0)) is the dominant species in anoxic sediments and is non-toxic. The oxidation and reduction of the As and Se aew mediated predominantly by the microbial populations present in the subsurface environments. Despite identification of many new isolates and ongoing research on the reduction and oxidation of the As and Se oxyanions has taken place, we still do not know much about the physiology and ecology of the diverse group of bacteria that mediate these processes. Further knowledge about selenate/selenite/arsenate-respiring organisms will provide a better understanding of the role microbes play in the cycling of these oxyanions. Selenospirillum indicus isolated in our laboratory, is the first cultured species of the proposed new genus Selenospirillum, capable of selenate, selenite, and arsenate reduction. Our specific objectives for this project include: a) Annotate the genome of Selenospirillum indicus genome, b) Identify of genes encoding respiratory reductases for arsenic and selenium by mutagenesis and/or disruption; c) Characterize gene regulation in presence/absence of arsenic and selenium and other respiratory electron acceptors (e.g. nitrate), d) Examine arsenic and selenium respiration from contaminated sites in New