e-mail: porwin@csusb.edu
B.S., Harvey Mudd College
Ph.D., University of Minnesota
BIOL 220 - Principles of Microbiology
BIOL 492 - Recombinant DNA Techniques
BIOL 320 - Microorganisms
Variovorax paradoxus is a soil microorganism associated with many vital biological transformations, including remediation of toxic compounds and promotion of plant growth. It has a tremendous variety of metabolic capacities, including heterotrophic growth on a large number of carbon sources, and lithoautotrophic growth using hydrogen gas and carbon dioxide as sources of energy and carbon, respectively. Our lab has focused on a critical component of soil survival and success, the ability to attach to and move on surfaces. The surface attached sessile phase, biofilm formation, is a crucial and widespread bacterial lifestyle, associated with virulence as well as environmental growth under many conditions. Swarming motility is a mechanism of bacterial movement on a surface that involves a number of cell surface appendages as well as production of a wetting agent and a hygroscopic matrix. The combination of surface attachment and motility, and the decision to move or "put down roots" is a crucial determinant of success in the heterogeneous soil environment. Our overall goal is to understand the structural components that underlie these two phenotypes, and the regulatory circuits that control these decisions.
In collaboration with Synedgen, Inc., our research group is examining the antimicrobial efficacy of various compounds chemically derived from the natural product chitosan, which is deacetylated chitin, the most common polysaccharide on Planet Earth. The proprietary derivatives manufactured by Synedgen, Inc and its corporate partners are being extensively characterized for antimicrobial activities against a broad spectrum of microbes, and our research group is focusing on efforts to determine the mechanism(s) of action of these novel compounds.
Orwin PM, Leung DYM, Bohach GA, Novick RP, and Schlievert PM. 2003. Biochemical and Biological Properties of Staphylococcal Enterotoxin L. Infect. Immun. (accepted for 5/03 issue)
Orwin PM, Leung DYM, Tripp TJ, Bohach GA, Earhart CA, Ohlendorf DH, and Schlievert PM. 2002. Characterization of a Novel Staphylococcal Enterotoxin-like Superantigen, a Member of the Group V Subfamily of Pyrogenic Toxins. Biochemistry, 41. 14033-14040.
Yarwood JM, McCormick JK, Paustian ML, Orwin PM, Kapur V, Schlievert PM. 2002. Characterization and Expression Analysis of Staphylococcus aureus Pathogenicity Island 3. Implications for the Evolution of Staphylococcal Pathogenicity Islands. J Biol Chem. 2002 Apr 12;277(15):13138-47.
Orwin PM, Leung DYM, Donahue HL, Novick RP, and Schlievert PM. 2001. Biochemical and Biological Properties of Staphylococcal Enterotoxin K. Infect. Immun. 69. 360-366.