title: Mode of sodium ion action on methanogenesis and ATPase of the moderate halophilic methanogenis bacterium Methanohalophilus halophilus.
abstract: Cells of Methanohalophilus halophilus swelled when exposed to hypotonic solutions of NaCl at pH 7.0. The swelling of the cells ceased in the presence of Mg2+. Methane formation by non-growing cells was strongly dependent on the NaCl concentration. Among other monovalent and divalent cations only Li+ and Mg2+ could partly substitute for a specific function of sodium ions. The artificial Na+/H+ antiporter, monensin, exerted a strong inhibitory effect on methane formation from methylamine. The membrane-bound Mg(2+)-stimulated ATPase of these cells was enhanced at low (40 mM) NaCl concentration while higher concentrations of this solute were inhibitory. The results obtained show that sodium ions are a prerequisite for optimal methane formation and ATPase activity in these cells. However, both of these processes required different sodium ion concentrations.
authors.affiliation: Institute of Animal Biochemistry and Genetics, Slovak Academy of Sciences, Ivanka pri Dunaji, Czechoslovakia.
authors.forename: P
authors.initials: P
authors.lastname: Smigán
authors.forename: P
authors.initials: P
authors.lastname: Rusnák
authors.forename: M
authors.initials: M
authors.lastname: Greksák
authors.forename: T N
authors.initials: TN
authors.lastname: Zhilina
authors.forename: G A
authors.initials: GA
authors.lastname: Zavarzin
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D019605:Euryarchaeota / Q000378:metabolism*; D008697:Methane / Q000378:metabolism*; D008744:Methylamines / Q000378:metabolism; D012964:Sodium / Q000378:metabolism*
chemical_list: D008744:Methylamines; D012964:Sodium; C027451:methylamine; D000251:Adenosine Triphosphatases; D008697:Methane