Leonard E. Mortenson

Leonard E. Mortenson was an internationally renowned researcher in biochemistry, a pioneering scientist and world leader in his field. Dr. Mortenson received his BS in chemistry-bacteriology from the University of Rhode Island in 1950. In 1952, he received his MS in biochemistry-bacteriology from the University of Wisconsin and continued there for his doctorate, which he received in 1954. Leonard was a research chemist with DuPont before coming to Purdue as an associate professor of biology in 1962. He remained at Purdue for 20 years, becoming a full professor. In 1981, he left to become senior research associate and group head at Exxon Research and Engineering Co. In 1985, he was appointed Fuller E. Callaway Professor of Biochemistry at the University of Georgia. He also was appointed chairman of the Division of Biological Sciences at Georgia and, in 1987, became the founder and director of the university’s Center for Metalloenzyme Studies. He retired in 1993. Dr. Mortenson was internationally renowned for his discovery of ferredoxin and for his research in the biochemistry of biological nitrogen fixation. He is especially noted for his studies of nitrogenase, the essential enzyme that reduces atmospheric nitrogen to ammonia. Mortenson was a pioneer in the identification, purification and characterization of other metal-sulfur proteins, including ferredoxin and hydrogenase. He can be considered one of the founders of the field of iron-sulfur proteins, whose importance now ranges from nitrogenase, hydrogenase and biological energy transduction to the regulation of DNA transcription. His work has been important in devising means of increasing nitrogen inputs to crop plants for the purpose of increasing yields.