Teresa Thiel
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Professor of Biology
Director of Biotechnology
Ph.D., Microbiology, Case Western Reserve University
Editorial Board of Journal of Bacteriology
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Phone: 314-516-6208
FAX: 314-516-6233
e-mail: thiel@umsl.edu
Department of Biology
University of Missouri- St. Louis
8001 Natural Bridge Rd.
St. Louis, MO 63121-4499
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Research Interests
(nitrogen fixation, cyanobacteria, gene regulation)
My research is in the area of microbiology and molecular biology, specifically on nitrogen fixation and gene regulation in filamentous cyanobacteria. We are interested in three sets of genes that encode the proteins requires for three independent nitrogenases that convert atmospheric nitrogen to ammonia. These genes are independently regulated by environmental conditions including the availability of metals such as molybdenum and vanadium or the anoxic or oxic state of the cells. We are interested in the molecular mechanisms that control the differential expression of the three sets of genes. In addition, we are interested in the evolution and phylogeny of these three sets of nitrogenase genes and their evolutionary origin.
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In situ expression of nif1 and nif2. (A and B) Strain TT216 (nif1::lacZ fusion) was induced aerobically for 24 hr as described in Thiel et al. (1995) prior to incubation with C12-FDG. A and B differ only in that filaments in B were photographed with a 560-nm shortpass filter to block the red fluorescence of the biliproteins. (C and D) Strain TT216 was induced anaerobically for 24 hr as above; same filament without (C) and with (D) a 560-nm filter. (E and F) Strain JE35 (nif2::lacZ fusion) was induced anaerobically for 6 hr (E) or 24 hr (F) prior to incubation with C12-FDG. Both photographs were taken with a 560-nm filter. White arrows indicate heterocysts identified from light micrographs. (Bars = 10um) |
Recent Publications
Thiel, T., Liczkowski, L., and S.T. Bissen. New zwitterionic butanesulfonic acids that extend the alkaline range of four families of Good buffers: evaluation for use in biological systems. J. Biochem. Biophys. Meth. In press.
Thiel, T. Genetics and regulation of multiple nitrogenases in the cyanobacterium Anabaena variabilis ATCC 29413. In: Cyanobacterial and Algal Metabolisms and Environmental Biotechnology. Edited by T. Fatma. Phycological Society. India. In press.
Thiel, T., Lyons, E.M., and Thielemier, J. Organization and regulation of two clusters of nif genes in the cyanobacterium Anabaena variabilis. pp. 517-521. In: Phototrophic Prokaryotes. Edited by G.A. Peschek, W. Loeffelhardt, and G. Schmetterer. Plenum Press, N.Y. (1998).
Heinlein, M., Wood, M.R., Thiel, T., and R.N. Beachy. Targeting and modification of prokaryotic cell-cell junctions by tobacco mosaic virus cell-to-cell movement protein. Plant J. 14: 345-351. (1998).
Thiel, T., Lyons, E.M. and J.C. Erker. Characterization of genes for a second Mo-dependent nitrogenase in the cyanobacterium Anabaena variabilis. J. Bacteriol. 179:5222-5225. (1997).
Thiel, T., Lyons, M., and M. Zahalak. Regulation of alternative nitrogenase systems by environmental factors in the cyanobacterium Anabaena variabilis. In Bothe, H. (ed.) Biological Fixation of Nitrogen for Ecology and Sustainable Agriculture. NATO ASI ser. G.Springer Verlag. pp. 159-162. (1997).
Thiel, T. Isolation and characterization of the vnfEN genes of the cyanobacterium Anabaena variabilis. J. Bacteriol.178:4493-4499 (1996).
Thiel, T., Lyons, E. M., Erker, J. C. and A. Ernst. A second nitrogenase in vegetative cells of a heterocyst-forming cyanobacterium. Proc. Natl. Acad. Sci. U.S.A. 92:9358-9362 (1995).
Zahalak, M., Beachy, R.N., and T. Thiel. Expression of the movement protein of tobacco mosaic virus in the cyanobacterium Anabaena sp. PCC 7120. Molecular Plant Microbe Interactions.8:192-199 (1995).
Lyons, E. and T. Thiel. Characterization of nifB, nifS, and nifU mutants of the cyanobacterium Anabaena variabilis: NifB is required for the V-dependent nitrogenase. J. Bacteriol. 177:1570-1575. (1995).
Thiel, T. Genetic analysis of cyanobacteria. In: Bryant, D.A. (Ed.) The Molecular Biology of the Cyanobacteria. Kluwer AcademicPress. Dordrecht, The Netherlands pp. 581-611. (1994).
Thiel, T. Characterization of genes for an alternative nitrogenase in the cyanobacterium Anabaena variabilis. J. Bacteriology175:6276-6286 (1993).
Teaching
Bio 338 - Gene Expression in Procaryotes
Bio 438 - Advanced Gene Expression in Procaryotes
Bio 489 - Graduate seminar in Topics in Microbial Genetics and Evolution