- Postdoctoral Fellow, University of California, Berkeley, 1991
- PhD, University of Wisconsin-Madison, 1987
- BS, University of Rochester, 1980
The molecular mechanism by which swimming bacteria are propelled through liquid media by rotating flagella is understood relatively well. Gliding motility (movement of cells over surfaces without the aid of flagella) is a trait common to many bacteria, yet the mechanisms responsible for gliding motility are poorly understood. My lab uses the techniques of genetics, molecular biology, biochemistry, and microscopy to determine the mechanism of Flavobacterium johnsoniae gliding motility. We developed techniques to allow genetic manipulation of this organism, and have used these techniques to isolate nonmotile mutants and to identify the genes that are altered in these mutants. These genes code for proteins that make up the gliding motility apparatus (‘motor’) that propels the cells. We use antibodies raised against these proteins to localize the components of the motor, determine how they interact, and visualize the gliding motility apparatus in cells. Based on our results we have developed a model for Flavobacterium gliding that involves the active movement of adhesive fibrils along the cell surface. We also identified a novel protein secretion system that is involved in assembly of the motility apparatus.
In addition to studies on gliding motility, we are also investigating other aspects of the biology of gliding bacteria. These bacteria are abundant in many environments and some have characteristics that make them important organisms to study. Examples of applied projects include studies of chitin digestion by F. johnsoniae, studies of cellulose digestion by Cytophaga hutchinsonii, and genetic analysis of the fish pathogens Flavobacterium psychrophilum and Flavobacterium columnare.