Micro-organisms alter the chemistry and productivity of aquatic environments by performing complex transformations of organic and inorganic molecules. In many cases, microbes can affect the speciation, mobility, bioavailability, and toxicity of toxic elements, such as Se, Hg, and As. The mechanisms by which these reactions proceed, the in situ rates of the transformation, their quantitative significance to element cycling, the responsible microorganisms and their physiology are only poorly understood. In this project, conceptual models of biogeochemical transformations will be developed by the combination of lab and field experimental work. Laboratory work will focus on identification of biochemical pathways, isolation and physiological [...]
Summary
Micro-organisms alter the chemistry and productivity of aquatic environments by performing complex transformations of organic and inorganic molecules. In many cases, microbes can affect the speciation, mobility, bioavailability, and toxicity of toxic elements, such as Se, Hg, and As. The mechanisms by which these reactions proceed, the in situ rates of the transformation, their quantitative significance to element cycling, the responsible microorganisms and their physiology are only poorly understood. In this project, conceptual models of biogeochemical transformations will be developed by the combination of lab and field experimental work. Laboratory work will focus on identification of biochemical pathways, isolation and physiological characterization of relevant microbes. Field work will consist of measuring in situ rates of transformations, based on methods developed in the laboratory. Physical exchanges between components, such as the flux of biogenic gases to or from the atmosphere from water or soil will be quantified.