Investigation of how physical, chemical, and biological processes influence soil development, groundwater flow, and the fate of microbial and chemical contaminants in modern surface and near-surface environments.
Annette Engel conducts interdisciplinary research that includes cave and karst aquifer evolution and speleogenesis, the role of natural organic matter in karst, geochemical controls on microbial metabolism, oil degradation and trajectories following environmental disturbances, the biodiversity of cave systems and coastal marine habitats, and symbiotic associations between bacteria and clams, invertebrates, and alligators. Her research falls broadly within the discipline of geomicrobiology, the study of the interactions between microorganisms and their geological and geochemical surroundings. Research involves a range of classical inorganic and organic geochemistry, stable isotope geochemistry, and molecular genetics methods within a microbial systems biology approach. Much of the instrumentation is available in Dr. Engel's laboratory. To quantify inorganic and organic compounds in water and gases, she applies basic wet and dry chemistry methods, ion chromatography, UV-Vis and fluorescence spectroscopy, Fourier transform infrared spectroscopy, gas chromatography, gas chromatography-mass spectrometry, and inductively coupled plasma mass spectrometry. She also uses X-ray diffraction and X-ray absorption spectroscopy using synchrotron radiation to understand mineralogical and elemental composition of natural materials. She uses stable isotope geochemistry, specifically of carbon, nitrogen, and sulfur, to characterize microbial signatures in water and sediment. For systems biology, she applies genomics and bioinformatics approaches that include DNA amplification protocols for PCR and quantitative PCR, and different gene sequencing methods, including next-generation high-throughput 454 and Illumina platform sequencing technologies to obtain DNA-based gene sequences and metagenomes ("who is there?") and also RNA-based transcriptomes ("what are they doing?") from environmental samples. To investigate metabolic potential directly from a sample, she routinely uses classical culturing methods and enzymatic assays. She also examines samples microscopically using gene probes for a full-cycle approach, where she can obtain genetic information and then probe material with specially designed probes to target specific microbes."
Terry Hazen's lab is a diverse group of scientific post doctoral fellows, research associates, technicians, and students in microbial ecology and environmental engineering. The primary research emphasis of the lab is basic and applied field microbial ecology, especially as it relates to bioremediation, biofuels, enhanced oil recovery, and water quality. The overarching vision for the lab is understanding the fundamental concepts of systems biology and environmental stress response pathways from the molecular to the ecosystem level to improve our knowledge of fundamental biogeochemistry and suggest exciting new applications that are relevant to the world's current problems. We have labs at both UT and Oak Ridge National Lab and active field studies in Puerto Rico, Alaska, Gulf of Mexico and Oak Ridge.
Melanie Mayes is Joint Faculty with the Climate Change Science Institute and the Environmental Sciences Division at the Oak Ridge National Laboratory. She conducts interdisciplinary research in carbon and nutrient cycling and in the fate and transport of metals, organics, and other contaminants in soils and rocks. She designs experiments to build better models of natural processes and is interested in diverse research at the intersection of water, minerals, solute chemistry, and biological cycling.
Her current research includes developing a mechanistic soil carbon cycling model that includes measurable soil carbon pools, sorption and desorption of dissolved organic carbon, and extracellular enzyme-facilitated decomposition of organic matter. The project also uses neutron reflectometry and molecular dynamics simulation to synergistically derive information on the molecular-level structure of organic carbon stabilized on soil minerals. She is actively involved with contaminant fate and transport, with two projects investigating the fate and transport of radionuclides and explosives, respectively, in aquifer materials at Departments of Energy and Defense facilities.
Larry McKay's research interests include: hydrogeology of fractured clay-rich residuum, fractured shale and glacial clay till; fate and transport of a variety of contaminant types, including industrial solvents, coal tar, radionuclides, explosives and pathogens; shale weathering; and paleosols. Dr. McKay was selected as the 2008 GSA Birdsall-Dreiss Distinguished Lecturer and visited approximately 55 universities or research institutions to give research talks.
Michael McKinney's research interests have generally focused on biological issues. He works on topics relating to modern biodiversity issues, such as the effects of urbanization on biodiversity, and especially how human activities are homogenizing the biosphere. I have served on the editorial boards of Evolutionary Ecology Research and Animal Conservation
Anna Szynkiewicz's interests involve studies of global geochemical and biogeochemical cycles related to the lithosphere and hydrosphere using stable isotope tracers (S-O-H-C-Zn) and chemical methods. This interdisciplinary research integrates areas of low-temperature geochemistry and water-rock interaction, hydrogeology, and environmental studies. Szynkiewicz is trying to integrate these fields in order to better quantify the chemical weathering of crustal rocks as a result of climate and to enhance knowledge and understanding of modern and past hydrological cycles on Earth.
Szynkiewicz also attempts to elucidate human impacts such as land cultivation and hydraulic fracturing on natural ecosystems. Consequently, her recent environmental studies have been focused on characterizing sources of salinity in agricultural districts of Chihuahuan and Sonoran Deserts as well as investigating sources of methane in groundwater of Central Appalachian Basin impacted by hydraulic fracturing and surface mining. Major research findings of these studies have been published recently in Chemical Geologyand Applied Geochemistry.Szynkiewicz's earliest research focused on the characterization of anthropogenic impacts on freshwater environments in Eastern Europe related to acid rain in mountain and lake ecosystems. She used multiple stable isotope tracers (S-O-H-C) to calculate the sulfate inputs from atmospheric acid wet deposition and performed several incubation experiments to evaluate the buffering capacity of lake sediments in response to anthropogenic acidification of freshwater. Major research findings of these studies have been published in Chemical Geologyand Applied Geochemistry.