Cell yield and superoxide dismutase activity of the marine yeast Debaryomyces hansenii under different culture conditions.

The effect of aeration, pH, stirring rate, and temperature on the biomass production and superoxide dismutase (SOD) activity of the marine yeast Debaryomyces hansenii strain C-11 was determined. The cell biomass yield was approximately 50% in a seawater-formulated medium using glucose as the carbon source. The SOD activity increased by application of a pulse of oxygen or 0.8 mM sulfate copper into the chemical reactor. The SOD enzyme had an activity of 400 units/mg of protein in a crude extract produced under such conditions, the best activity ever reported for this enzyme in a crude preparation.