The Biocatalysis Studies Topic investigates the role of microbes (primarily bacteria) in the geochemical cycles of arsenic, mercury, iron, lead, and zinc. The central theme of this topic is to determine the impact of microbes on the aqueous geochemistry of elements of environmental interest, namely As, Hg, Fe, Pb, and Zn. The task will examine 1) microbial controls on arsenic redox geochemistry, speciation, and mobility, 2) factors that control the rates and pathways of microbial methylmercury [MeHg] production, and 3) the interaction of iron- and sulfur-oxidizing bacteria with the surfaces of Zn- and Pb-bearing ore sulfides and secondary Fe-oxides. The work will be accomplished by employing the lab experiments and field applications described below. The data obtained from these research studies will enhance our ability to predict [model] the mobility of As, Hg, Fe, Pb, and Zn in environments where microbial populations or consortia are present to act as biocatalytic agents.
- Rates of Microbially-mediated Ferrihydrite and MnO2 Dissolution: Evidence for Slower Reaction Rates due to Decreased Surface Reduction Sites and Increased Dissolved Metals
- Bacterial Sorption to Sulfide Mineral Surfaces
- Microbial Methylmercury Production in Soil
- Development of a Technique for the Rapid Screening of Microbial Diversity in Environmental Samples
- Field Calibration of Stable Isotopic Fractionation Associated with Biotic and Abiotic Sulfate Removal Processes