K. T. Shanmugam

Professor

Department of Microbiology and Cell Science University of Florida 
Ph.D. (1969) Department of Microbiology; University of Hawaii 
Postdoctoral: (1969-1971) Department of Cell Physiology; University of California, Berkeley

Teaching Interest

Bacterial Physiology

MCB4303L, Bacterial Genetics laboratory

Description of Research

General area: bacterial anaerobic metabolism; dinitrogen fixation and dihydrogen production by fermentative bacteria and cyanobacteria; molybdate transport and regulation.

Current research in Dr. Shanmugam's laboratory is focused on the physiological processes leading to synthesis of molybdoenzymes in a bacterial cell. Although required only in small amounts, molybdenum is an essential element in higher forms of life and plays a crucial role in global nitrogen cycle. The molybdoenzymes, dinitrogenase and nitrate reductase are two main enzymes which help convert inorganic nitrogen compounds, dinitrogen and nitrate, respectively, to ammonia, a form readily used by microorganisms for synthesis of cell material. The transport of molybdate, genetic regulation of genes coding for the various transport proteins as well as the regulation of the genes coding for molybdoenzymes are three areas of study at the present time. These experiments are conducted with Escherichia coli.

Besides the studies on molybdate metabolism in E. coli, Dr. Shanmugam's research interest also extends to the use of cyanobacteria as a catalyst in a solar energy dependent production of ammonia from dinitrogen. Such ammonia-excreting mutant strains of cyanobacteria which are similar to symbiotic dinitrogen-fixing organisms can be used as a supplier of ammonia for plant growth. Cyanobacteria can also be used as choice organisms in the fermentation of sugars exclusively to dihydrogen. Both of these processes are catalyzed by dinitrogenase, a molybdoenzyme.

Top

Selected Publications

Underwood, S. A., M. L. Buszko, K. T. Shanmugam and L. O. Ingram. 2004. Lack of protective osmolytes limits final cell density and volumetric productivity of ethanologenic Escherichia coli KO11 during xylose fermentation. Appl. Env. Microbiol.70:2734-2740.

Self, W. T., A. Hasona and K. T. Shanmugam. 2004. Expression and regulation of a silent operon, hyf, coding for hydrogenase 4 isoenzyme in Escherichia coli. J. Bacteriol. 186:580-587.

Causey, T., K. T. Shanmugam, L. Yomano and L. O. Ingram. 2004. Engineering Escherichia coli for efficient conversion of glucose to pyruvate. Proc. Natl. Acad. Sci. USA 101:2235-2240.

Patel, M., M. Ou, L. O. Ingram and K. T. Shanmugam. 2004. Fermentation of sugar cane bagasse hemicellulose hydrolysate to L(+)- lactic acid by a thermotolerant acidophilic Bacillus sp. Biotech. Letters 26:865-868.

Hasona, A., Y. Kim, F. G. Healy, L. O. Ingram and K. T. Shanmugam. 2004. Pyruvate formate lyase and acetate kinase are essential for anaerobic growth of Escherichia coli on xylose. J. Bacteriol. 186:7593‑7600.

Shukla, V. B., S. Zhou, L. P. Yomano, K. T. Shanmugam, J. F. Preston and L. O. Ingram. 2004. Production of D(‑)‑lactate from sucrose and molasses. Biotechnol. Lett. 26:689‑693.

Top