[Effect of ammonium on certain oxidoreductases of wine yeasts]

The effect of ammonium ions on the activity of alcohol:NAD-, L-malate:NAD-, L-glutamate:NADP-oxidoreductases was studied in wine yeast during fermentation of wine wort containing 18% of sugar, and also after the biomass cultivated in the conditions of nitrogen deficiency had been transferred to media with various amounts of nitrogen and carbohydrates. Ammonium stimulated the activity of all these enzymes during fermentation and their activity in the biomass transferred to a medium with a low content of nutrient component; its effect was less pronounced on a complete medium.