Submitted to: American Society of Microbiology Newsletter
Publication Type: Popular Publication
Publication Acceptance Date: 1/30/2005
Publication Date: 1/31/2005
Citation: Chung, K., Hungate, B., Russell, J.B. 2005. Robert E. Hungate. American Society of Microbiology Newsletter. p. 34.
Technical Abstract: Robert E. Hungate, Professor Emeritus, Department of Bacteriology, University of California, Davis, passed away the morning of 21 September 2004. He was born on 2 March 1906 in Cheney, Wash., and graduated from the State Normal School (now Eastern Washington State University) in 1924. After working as a school teacher for three years, he entered Stanford University and obtained his A.B. magna cum laude in 1929. At Stanford he also met and married in 1933 Alice Elizabeth Wolcott. They were married 67 years before her death in January 2000. He was the first Ph.D. student of C. B. Van Niel, a leading creative microbiologist of this country and a member of the "Delft School." Hungate received his Ph.D. in 1935. He pioneered the study of cellulose digestion by protozoa in termites. In 1935, he joined the staff of the Department of Zoology at the University of Texas as an instructor and continued to work on the nitrogen economy of the damp-wood termite gut. He soon turned his attention to the problem of cellulose digestion in cattle. Hungate established cultures of individual protozoa and later isolated strictly anaerobic bacteria also capable of digesting cellulose. Hungate's success as a microbial ecologist was largely based on a simple but ingenuous technique of maintaining anaerobiosis. Anaerobiosis was achieved by flushing the culture tubes with O2-free CO2. The CO2 was initially purified with a chromous acid solution, but later work showed that the same effect could be was achieved by passing it through a hot copper column previously reduced with hydrogen. After the tubes were filled, they were closed with butyl rubber stoppers. Tubes containing molten agar were "rolled" in an ice bath to create a film of agar on the inside surface. Once colonies had developed, the tubes were opened, and isolates were transferred to anaerobic broth. This latter step was performed via a Pastuer pipette and a "mouth tube" also filled with O2-free CO2. With the availability of Hungate's "roll tube method," many anaerobic bacteria including cellulolytic ones such as Bacteriodes (now Fibrobacter) succinogenes and Micromonospora propionici. Many students and postdoctoral scientists joined his effort. Some of the interesting findings included quantitative measurements of rumen fermentation, interpretation of rumen disorders (acidosis and bloat), continuous culture fermentations, and isolation of methanogenic bacteria. This technique was spread to other laboratories, and over the years scientists from many different countries came to Hungate's laboratory to study anaerobic bacteria. Hungate's interest in microbial ecosystems started from insects such as termites but extended to bovine rumen. He developed a concept that a complete analysis of an ecosystem involved not only identification of microbial species and their activities, but also the measurement and quantitation of these activities. Hungate demonstrated that individual species from this unique habitat were members of beautiful interdependent groups. Through Hungate's efforts, rumen became the most well-characterized microbial ecosystem. He published his work in a book, The Rumen and Its Microbes (Academic Press, New York, 1966), which provides the best in-depth understanding of this unique ecosystem. The impact of Hungate's research has been tremendous. With Hungate's roll tube anaerobic technique, other ecosystems such as the human intestine have been extensively explored by other scientists. We have now a much better understanding of the importance of human intestinal microorganisms related to health. Hungate also pioneered the isolation of methanogens, which were later isolated from many other habitats. He is regarded by many as the father of anaerobic microbiology. A "Centennial Celebration of the Life of Robert Hungate" is currently being planned for the 2006 Annual ASM M