Research in Microbial Geochemistry at UVM

We study the interdependence of microbial activity and geochemical cycling in a range of environments.  The goal is to gain insight on defining the role of microbes in different environments - how much they affect the stability and transport of a variety of compounds in those environments.  Germaine topics addressing these questions include the kinetics of redox reactions such as the oxidation of pyrite, elemental sulfur, and ferrous iron, molecular clusters and reactions driving nanoparticle formation and dissolution, relating microbial ecology to geochemical niches, and the application of thermodynamic, kinetic, and molecular models to predictive analysis of environmental perturbation.

This research is complimented by the development and application of new methods for analyzing redox chemistry and nanoparticulate materials associated with microbial activity.   Coupling geochemical and microbial ecology dynamics through rigorous characterization of the redox chemistry, nutrient availability, and other geochemical constraints is approached, in collaboration with Dr. Donna Rizzo (UVM), through the application of new geostatistical and other computational algorithms. The application of in situ redox sensors and new techniques for chromatographic identification and quantification of redox species, molecular clusters, and nanoparticles is also of particular interest. 

Research Topics
Sulfur chemistry and microbial ecology 
Metal Sulfide Molecular Clusters: precursors to nanocrystal formation in the environment
Iron isotope fractionation in the Fe-S system
Frassassi cave project: Geochemistry and microbiology of a sulfidic karst system in central Italy
Redox dynamics and phosphrous cycling in Lake Champlain
Expanding the limits of application for environemntal voltammetry
Circumneutral Fe2+ oxidation kinetics: Competetive kinetics and microbial niches
Application of Artificial Neural Networks to work with large datasets of geochemical and microbial data