Mike Dunn

I earned my B. S. degree in Biology from Delaware Valley University in 1985 and my Ph.D in Plant Pathology from the University of Missouri-Columbia in 1987. Despite my doctorate in plant pathology, I have always worked in the area of biological nitrogen fixation. In 1992, I began my post-doctoral research at the National Autonomous University of Mexico’s Nitrogen Fixation Research Center. There I studied carbon metabolism in the nitrogen-fixing bacteria Rhizobium etli and Sinorhizobium meliloti, mainly biotin metabolism and the characteriztion of biotin-dependent enzymes. In 2004, the Nitrogen Fixation Research Center became the Center for Genomic Sciences. As a tenured Research Professor I focused on the functional genomics of rhizobial carbon metabolism until about 2012. My interest in rhizobial metabolism then shifted from carbon to nitrogen, specifically to the genetics and biochemistry of ornithine and arginine synthesis in S. meliloti. My current research focuses on polyamines, which are derived from ornithine in S. meliloti. We have described key points in the regulation of ornithine and polyamine biosynthesis and several physiological roles of polyamines in S. meliloti in free life and in symbiosis with alfalfa. We are currently investigating the molecular mechanisms behind the phenotypic effect exerted by polyamines.