Chapter 34 : Captivating Methanogens

Abstract:

As a graduate student, the author was attracted to microbial physiology and metabolism. Techniques such as sonic oscillation had been developed for the rupture of bacterial cell walls; enzyme activity in cell extracts could also be studied. The author worked on the enzyme hippuricase (from Streptococcus), a hydrolytic enzyme that cleaved a peptide-like bond and was considered of interest because the mechanism of peptide bond synthesis was unknown at the time. In 1961, the author began to study methanogenic bacteria, and these studies, over a twenty-year period, led to work on six new coenzymes of methanogenesis: coenzyme M, coenzyme F420, tetrahydromethanopterin, coenzyme F430, methanofuran, and coenzyme B. A major portion of the author's research career was devoted to enzyme-coenzyme relationships in the reduction of carbon dioxide to methane. The first new coenzyme of methanogenesis, coenzyme M (CoM), was required as a vitamin by Methane-bacterium ruminantium. In the summer of 1954, the author became an observer in van Niel's famous course at Pacific Grove. This fantastic experience enabled him to start his own organisms course. Through assignment of special problems, both the students and the author learned something new about an unusual organism each time the course was given. The author had a continuing interest in unusual organisms: Gallionella, Beggiatoa, magnetic bacteria, photosynthetic bacteria, acetogens, and methanogens.