Molecular Environmental Soil Science
Critical environmental processes are often driven by micro- to molecular
scale phenomena. The Molecular Environmental Soil Science (MESS) research
program seeks to understand the fundamental biological and chemical processes
that control the speciation, transformation, bioavailability, fate, and
transport of nutrients and contaminants in the environment. To approach these
complex problems, investigations hinge on blending cutting-edge spectroscopic,
microscopic, and molecular techniques with traditional chemical and
microbiological approaches in both field and laboratory studies. These studies
develop the basic scientific understanding that underpins the development of
sound management strategies.
The solid and aqueous phase speciation of chemicals in soils determines
their mobility and bioavailability. For example, precisely managing phosphorus
as both a plant nutrient and an environmental contaminant will be best
accomplished from a fundamental
Fundamental features of X-ray absorbtion spectra.
understanding of the chemical species present
in a soil and the reactivity of these species.
Dean Hesterberg
(Soil Physical Chemistry) uses advanced X-ray spectroscopic techniques to
determine solid-phase chemical species of phosphorus and trace elements in soils,
and to study their reactivity. Research ranges from molecular-scale
characterization to direct observation of contaminant dissolution in soil
materials.
Microorganisms play fundamental roles in many soil processes including but
not limited to soil carbon sequestration, nitrogen and phosphorus cycling, and
detoxification of inorganic and organic pollutants. Soil microbes regulate
these processes through their survival strategies at the organismal level,
competitive and synergistic interactions at the community level, and feedback
control mechanisms at the ecosystem level.
Wei Shi
(Soil Microbiology and Ecology) uses molecular biology, biochemical, and
ecological approaches
Phyogenetic analysis of microbial community associated with the nitrogen
cycle. to address questions regarding soil microbial
ecophysiology, community diversity and composition, and the cycling of carbon,
nitrogen, and phosphorus in managed and natural ecosystems. Soil Microbiology
and Ecology Program is equipped with or able to access the tools for conducting
organismal, community, and process-level studies.
Alexandria Graves (Soil and Environmental Microbiologist) uses nucleic acid-based methods for the identification of enteric bacteria (E. coli, Enterococcus, Salmonella, etc.) recovered from soil and water matrices. The use of PCR provides the capability to detect the presence of enteric bacteria without relying on the need to culture the target microorganisms. This tool also provides the ability to track several different genes concomitantly, thus allowing for a greater level of confidence in microbial source tracking and pathogen detection.
The biogeochemistry of many nutrients and contaminants in the environment
is mediated by microbes and mineral surfaces.
Owen Duckworth
(Soil Biogeochemistry)
focuses primarily on the thermodynamics and kinetics of
aqueous and interfacial reactions that control the biogeochemical cycling of
natural and anthropogenic species. Specific interests include the effects of
biogenic exudates, including small organic acids, biopolymers, and
siderophores, on the speciation and solublization of trace metals in the
environment, and the biomineraization and bioweathering of oxide and carbonate
minerals. A wide array of spectroscopic and microscopic techniques are used
to support macroscopic observations derived from traditional chemical and
microbiological
Atomic force microscope image of a dissolving calcite crystal. approaches.
Students trained in the MESS program will develop diverse technical skills and a multidisciplinary perspective on soils and the environment. Prospective students interested in any of these topics, or applying these techniques and approaches to other problems, should feel free to contact any of the faculty listed above for more information.