Ectoine as the predominant osmolyte in the marine bacterium Marinobacter hydrocarbonoclasticus grown on eicosane at high salinities

Ectoine was detected by C-13-nuclear magnetic resonance spectroscopy in extracts of the halophilic marine bacterium Marinobacter hydrocarbonoclasticus grown at different NaCl concentrations (0.6, 1.5, 2.5 mol l(-1)) in synthetic seawater on eicosane as the sole source of carbon and energy. Ectoine was synthesized as the principal osmolyte in response to stress. However, when the medium was supplemented with glycine betaine, this osmolyte was transported into the cells and replaced ectoine.