Affiliations

Professor, Microbiology, Immunology & Molecular Genetics

Member, Biochemistry, Biophysics & Structural Biology GPB Home Area, Genetics & Genomics GPB Home Area, I3T Theme, Immunity, Microbes & Molecular Pathogenesis GPB Home Area, Microbiology, Immunology & Molecular Genetics

Research interests of the Gunsalus laboratory address the physiology and molecular biology of gene expression in the Bacteria and Archaea. We are studying how cells sense changing environmental conditions, and adapt their metabolism accordingly. Experimental approaches being used include whole genome DNA microarrays, classical microbial genetics, biochemistry, and molecular/structural biology. Model organisms include the methanogenic Archaea (Methanosarcina acetivorans and Methanosarcina mazei) and enteric bacterial species including Escherichia coli K-12. The former two microbes produce methane from the biological precursors, acetate, methanol, methyl-amines, and in most instances, H2/CO2. We are identifying the gene families involved in use of the alternative carbon substrates leading to methane formation with the goal of understanding the regulatory networks and the key regulatory factors. The Methanosarcina are also versatile in their ability to withstand stress; for example, they can grow fresh water environments, marine environments, and to hyper saline environments (ca to 1.2 M NaCl). They do so by synthesis and/or transport of osmolytes (i.e., N-acetyl-beta-lysine, alpha-glutamate, betaine, and potassium) whereby the levels of these osmolytes are modulated over a wide range to adjust osmotic balance. Finally, we are examining the regulatory mechanisms that allow the common enteric bacterium, E. coli to switch from aerobic to anaerobic growth. This ability allows comensual as well as pathogenic strains to adapt and grow successfully inside and outside the human body by using a variety of genetically programmed strategies.