Patricia Sobecky, Associate Professor
Ph.D. Microbiology, University of Georgia, 1993
Phone: (404) 894-5819
Fax: (404) 894-0519
Office: (ES&T) 1242/1121
Environmental Microbiology/Microbial Ecology
We are located in the School of Biology at the Georgia Institute of Technology. Our lab investigates various aspects of environmental microbiology including characterizing horizontal gene transfer (HGT) of microbial plasmid systems, bioremediation of soils systems, marine microbial pathogen survival and adaptation and microbial biofouling of concrete infrastructures. We employ modern microbiological techniques to address these various areas. We seek to address fundamental and basic research questions with the goal of developing innovative strategies for sustainable ecosystem health by understanding critical microbial activities.
We are currently conducting research in the following areas:
- Bioremediation of subsurface soils contaminated with radionuclide and heavy metals. Bioremediation of subsurface soils contaminated with radionuclide and heavy metals. The treatment of hazardous mixed waste sites, particularly those co-contaminated with heavy metals and radionuclides, remains one of the most costly environmental challenges currently faced by the U.S. and other countries. Our research focuses microbial heavy metal efflux systems and microbial phosphatases that are necessary for cell survival in addition to possible applications as bioremediation strategies. Our work specifically focuses on determining if microbial phosphatases in natural subsurface microbial communities can be stimulated for the purpose of precipitating soluble hexavalent uranium as a phosphate mineral. Our ongoing experiments are designed to address the microbial and geochemical mechanisms that promote radionuclide biomineralization and sequestration in oxygenated subsurface soil and groundwater. This work is funded by the Department of Energy's Environmental Remediation Science Program.
- Vibrio parahaemolyticus survival and adaptation. The incidence of gastrointestinal illnesses, wound infections, and septicemia caused by species of the genus Vibrio is rising dramatically. Among the ubiquitous Vibrio species occurring in coastal marine and estuarine environments is Vibrio parahaemolyticus, an opportunistic human pathogen. V. parahaemolyticus presently accounts for the majority of Vibrio infections in the United States. The emergence of the serotype O3:K6 in 1996 is now the first documented V. parahaemolyticus serotype to cause global, pandemic disease. Increases in V. parahaemolyticus-associated outbreaks may be due to the emergence and evolution of novel genotypes that promote the organism's expansion to new niches, host populations or enhance its ability to cause disease. Our studies are addressing the molecular mechanisms and associated mobile genetic elements facilitating the emergence of V. parahaemolyticus pathogens to better understand the threat of this emerging pathogen. Understanding molecular processes that promote rapid genome evolution will yield insights into the evolution of V. parahaemolyticus pathogenicity and the emergence of new serotypes of this opportunistic pathogen. This work is funded in part by the CDC/Georgia Tech Seed Grant Program.
- Microbial biofouling. A goal of this research project is to identify the species of microorganisms (prokaryotic and eukaryotic) which may be colonizing and fouling the concrete infrastructure (highways, bridges) in Georgia. We are applying modern molecular techniques in addition to traditional microbiological methods to determine microbial community structure. A key outcome of this research will be to develop recommendations regarding effective and practical means to reduce the occurrence of microbial biofilms on concrete infrastructure. This work is conducted in collaboration with Dr. Kim Kurtis's (Civil and Environmental Engineering, GT) research group, funding is provided by the Georgia Department of Transportation.
Examples of other recent projects:
- Life in Extreme Environments (Gulf of Mexico). The northern continental slope of the Gulf of Mexico, a hydrocarbon seep region, contains vast reservoirs of oil and gas deposits, areas of active gas venting and gas hydrate mounds occurring as seafloor outcroppings and in the shallow subsurface. The ice-like gas hydrate, composed of water and hydrocarbon gas molecules (predominately methane), requires suitable gas, temperature and pressure conditions for formation and stability. Although such conditions occur globally, with gas hydrates distributed in many marine (active and passive continental margins) and terrestrial locales, focused seep locations in the shallow Gulf of Mexico basin provide a unique access to abundant gas hydrate mounds and associated sediments at the seafloor. Gas hydrates have become the subject of intense investigation owing to their potential use as an alternative energy resource, possible effect on sea-floor stability, change in climatic conditions and presence on other planets and satellites. In collaboration with researchers from GT, UGA and Texas A&M, sediments and gas hydrate were sampled by deploying a custom-made hydrate drill from a manned research submersible at two different GoM cold seep locations (550-575 m water depth). The objective was to characterize the sediment microbial community in direct contact with surface breaching gas hydrates. Our studies are among the first 16S rDNA gene surveys to be conducted on free-living GoM seep sediment microbial communities directly associated with surface-breaching gas hydrate mounds. Funding for this research was provided by a number of agencies including the NSF, DOE NETL and NOAA NURP.
- Marine Plasmid Ecology. To investigate plasmid distribution and plasmid-mediated effects on marine microbial community activities, plasmids, extrachromosomal accessory genetic elements, are obtained from marine sediment bacterial populations and characterized at the molecular level. DNA probes specific for replication regions (e.g., plasmid incompatibility-group probes) are used to characterize the distribution, diversity and persistence of these replicons in marine environments. Marine plasmids are also being sequenced to determine biological functions. The transfer dynamics of plasmids are also determined by elucidating environmental and molecular constraints likely to affect horizontal gene exchange. In addition, we have developed new molecular techniques to rapidly assess plasmid populations along spatial and temporal scales. Funding for this research effort has been provided by the Office of Naval Research.