The Nitrogenase in a Methanogenic Archaebacterium and Its Regulation.

The objectives of this project are to gain an understanding of the process of nitrogen fixation in the methanogenic archaebacterium, Methanosarcina barkeri strain 227. Initial studies centered on the growth physiology of M. barkeri under diazotrophic conditions. We have also demonstrated that crude extracts of diazotrophic M. Barkeri reduce acetylene at a very low rate, but apparently reduce dinitrogen to ammonia at a 20-fold higher rate per electron. Among the objectives for the coming year are further characterization of reactions carried out by the nitrogenase in crude extracts, and purification of the nitrogenase enzymes.