Halotolerance in Methanosarcina spp.: Role of N(sup(epsilon))-Acetyl-(beta)-Lysine, (alpha)-Glutamate, Glycine Betaine, and K(sup+) as Compatible Solutes for Osmotic Adaptation.

摘要: The methanogenic Archaea, like the Bacteria and Eucarya, possess several osmoregulatory strategies that enable them to adapt osmotic changes in their environment. physiological responses of Methanosarcina species different pressures were studied extracellular osmolalities ranging from 0.3 2.0 osmol/kg. Regardless isolation source, maximum rate growth for freshwater, sewage, marine sources occurred between 0.62 1.0 osmol/kg decreased minimal detectable as solute concentration approached steady-state water-accessible volume thermophila showed a disproportionate decrease 30% 0.6 then linear 22% media increased total intracellular K(sup+) ion M. 0.12 0.5 mol/kg medium osmolality was raised remained above 0.4 Concurrent with accumulation, synthesized accumulated (alpha)-glutamate predominant osmoprotectant containing up osmol per kg. At greater than osmol/kg, leveled off zwitterionic (beta)-amino acid N(sup(epsilon))-acetyl-(beta)-lysine synthesized, accumulating an exceeding 1.1 at When glycine betaine added culture medium, it caused partial repression de novo synthesis by cell compatible solute. distribution solutes eight strains representing five spp. similar those found grown Results this study demonstrate mechanism halotolerance involves regulation K(sup+), (alpha)-glutamate, N(sup(epsilon))-acetyl-(beta)-lysine, accumulation response effects