DOE final report: Studies on the microbial formation of methane

The microbial formation of methane is carried out by methanogens which are found wherever active anaerobic degradation of organic matter occurs. We developed a procedure for reliable culture of 'Methanococus jannaschii' which yields 8 g wet weight of cells per liter of medium. To initiate a study of proteomics, this organism was grown at two levels of hydrogen partial pressure, very low (650 Pa) and high (178 kPa). When cells were exposed to hydrogen excess conditions, they possessed very low or undetectable levels of four flagella-related polypeptides, whereas, when hydrogen became limiting, these proteins were synthesized. Thus, use of proteomics showed, for the first time, that this methanogen can regulate expression of proteins, and these experiments open the door for general studies of regulation in this hyperthermophile