Irwin Clyde Gunsalus was born in South Dakota. After spending 2 years as a chemistry major at South Dakota State College in Brookings, South Dakota, he transferred to Cornell University and received his B.S. in 1935. He stayed at Cornell to pursue graduate study in bacteriology and was awarded his Ph.D. in 1940. Gunsalus was then invited to join the faculty of the department, where he remained for 7 years. In 1947, Gunsalus moved to Indiana University to serve as a professor of bacteriology. Three years later, he was enticed to move to the newly developing Department of Microbiology at the University of Illinois in Urbana, and in 1955 he became head of the biochemistry division in the Department of Chemistry. Gunsalus also served as a professor emeritus of biochemistry at the University of Illinois until his death.
Gunsalus was a prime figure in the movement of bacteriology into modern microbiology incorporating biochemistry, the physical sciences, molecular biology, and genetics. In his early research on bacterial growth factors, he discovered pyridoxal phosphate and lipoic acid. During his time in Illinois, Gunsalus developed a genetic system for the study of Pseudomonas, dissected the 11-step pathway for terpene breakdown, discovered the first three-component microbial cytochrome P450 system involved in this pathway, and purified and crystallized the hemoprotein component of cytochrome P450. Gunsalus' P450 research was featured as a Journal of Biological Chemistry Classic (1).
Gunsalus received numerous honors and awards, including election to the American Academy of Arts and Sciences, the American Academy of Microbiology, and the National Academy of Sciences. He also received the Mead Johnson Award in Biochemistry, the Selman Waksman Award, and the William C. Rose Award in Biochemistry and Molecular Biology. He served as president of the American Society of Biological Chemists in 1974 and also as president of the Federation of American Societies for Experimental Biology.
1. Kresge, N., Simoni, R. D., and Hill, R. L. (2007) The bacterial cytochrome P-450 and Irwin C. Gunsalus. J. Biol. Chem. 280 (5)