Stenotrophomonas maltophilia ORO2 (S. maltophilia O2) was isolated from a heavy metal contaminated stream in Oak Ridge, TN. This strain demonstrated the ability to precipitate selenite, an inorganic form of selenium. Selenium is an essential trace element for all living organisms, but exposure to high concentrations in the form of selenite can be lethal. This research will focus on the ability of selenite resistant bacteria to process selenium when exposed to toxic levels of selenite. A S. maltophilia O2 gene, which may be involved in selenite resistance, was transferred to and conferred selenite resistance in a common laboratory strain of Escherichia coli (E. coli). Mechanisms of resistance will be studied using proteomics to examine the total number of proteins expressed under certain growth conditions. Selenite resistant strains of S. maltophilia O2 and E. coli will be grown in two different cultures, one with toxic levels of selenite and the other without selenite. Proteins from bacteria grown under each condition will be isolated and separated using 2-dimensional gel electrophoresis. The intensity of spots in the two gels will show which proteins are more abundant in the presence of selenite than in its absence. The proteins in the spots will then be identified using a mass spectrometry technique. By identifying and studying proteins expressed in the presence of high selenite concentrations, it will be possible to understand selenium homeostasis (a balance of selenium intake with selenium detoxification) in bacteria. Results from this research may also provide insights into the role of selenium as an antioxidant. The broader educational impact of this project will be tremendous. This research will introduce underrepresented minority students in the Youngstown Early College (YEC) program (seventy-three percent of the students in this program are underrepresented minorities) to a career in science and contribute to the educational focus of the Youngstown 2010, a plan to revive the arts, health care, government, and education of the city. The YEC is a program in which the Youngstown city school district collaborates with Youngstown State University to provide underprivileged high school students with the opportunity to receive their high school education in a university setting. While these students have access to some of the college courses on campus, they do not have the opportunity to work in research laboratories. YEC students will be invited to participate in the research project on selenite resistance.
