Research Interests
My research is directed towards understanding the molecular genetic mechanisms utilized by microorganisms to respond to changes in their environment. Two systems are being examined, the hyperthermophilic archaeon Pyrococcus furiosus and the spore-forming bacterium Bacillus subtilis.

P. furiosus ("furious fireball!") grows optimally near the boiling point of water and is representative of micoorganisms found near deep-sea hydrothermal vent communities. The hyperthermophiles are gold mines for biotechnologically important products, e.g. proteins, that demonstrate enhanced biological activity and stability at high temperatures. We have isolated a group of genes whose expression is related to the presence, in the growth medium, of the sugar maltose. By studying the mechanisms involved in controlling these maltose-regulated genes, we hope to determine the molecular signals and response elements used by the organism to regulate gene expression in general. This research should allow for the identification of novel biological mechanisms that will lead to, among other things, new applications of thermostable processes.

The regulation of nitrogen metabolism has been the focus of our studies in B. subtilis. Bacillus species have been the workhorses of biotechnology, being used for the production of a number of products from antibiotics to detergent additives. These products are often made when the organism is challenged with a stress, e.g. the deprivation of a source of nitrogen. We have been studying glutamine synthetase (GS), the enzyme responsible for producing glutamine, an amino acid used for the synthesis of 80% of the organism's nitrogen-containing compounds. In addition, GS is the only pathway for ammonia assimilation and its production is coupled to environmental signals. Thus, understanding how GS synthesis is regulated will provide insight into how the organism gauges and responds to nutrient deprivation.