Complexity Science Seminar Series - Abstracts
Presenter: Dr. Biswarup Mukhopadhyay
Virginia Bioinformatics Institute, Virginia Tech
Date and Time: Monday, March 26, 2007, 3:00-4:00 PM
Abstract:
Microorganisms have been found to withstand and even thrive under a variety of extreme conditions. In our laboratory we focus on microbial metabolism at very high temperatures and under oxidative stress conditions. For the former we study Methanocaldococcus jannaschii that lives in the deep-sea hydrothermal vents (undersea volcanoes). The organism produces methane via one of the oldest respiratory metabolic systems of earth that was developed about 3 billion years ago. M. jannaschii grows fastest at 85 °C and can use only hydrogen as the energy source. It is an archaeon, a recently described domain of life distinct from the eukaryotes (mold, plant, animal, human) and the bacteria. It has a small genome (1.74 Mbp), yet synthesizes the entire cell from hydrogen, carbon dioxide and inorganic salts. Therefore, M. jannaschii represents a minimum requirement for life to exist independently, and in its environment it is the primary producer. Geochemical data and modeling suggest that within the vent M. jannaschii periodically experiences large fluctuations (up to 50,000-fold) in hydrogen (energy) supply and gets exposed to toxic chemicals such as sulfite. Our proteomics data show that the organism uses novel metabolic systems to cope with such stresses. These data also helped us to put forward a hypothesis on the development of two of the oldest respiratory metabolisms of earth, methanogenesis and sulfate reduction. For our work on the microbial oxidative damage defense systems, we focus on Mycobacterium tuberculosis, which causes tuberculosis. The guiding hypothesis for this project is that in the process of combating oxidative attack or while lying dormant within the host, the organism undergoes genomic transformations that make it more resistant to host defense systems and/or therapeutic agents; the latter phenomenon leads to the development of multi-drug resistant strains. It is possible that other host factors or environmental conditions promote such transformations and a large-scale modeling approach can shed some light on this possibility.Seminar Location: The seminars are held at:
Virginia Tech, Corporate Research Center
1880 Pratt Drive, Building XV
Seminar Room 2018, Second Floor
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