This research investigates problems of bioremediation (trichloroethylene degradation by methane-utilizing bacteria) and trace gas cycling (utilization of the greenhouse gases methane and methyl halides by methylotrophs). Laboratory experiments to study substrate utilization kinetics and regulation will be coupled with studies of field samples to assess the methylotrophic populations (with gene probes), compare the substrate utilization kinetics, and determine how the natural populations respond to perturbations such as changes in growth rate or nutrient concentrations. Predictive models will be generated from the laboratory data, tested with field samples (soil and water), then refined by further laboratory work and retesting. This comprehensive approach will define how these activities are expressed in natural samples and result in mechanistically-based predictive models with immediate applications to bioremediation and global trace gas modeling.
