| Abstract: | The fermentation of maltose and maltotriose in metal-free buffer solutions strongly depends on the pH value; the optimum pH is close to 5·0 and activity diminishes to zero above pH 7·2. Potassium stimulates utilization of these sugars at pH values of 5·0 and below, but in contrast to the situation with glucose, pH still influences fermentation markedly in the presence of potassium. Both pH and potassium influence sugar uptake rather than internal metabolism. Zinc, magnesium and ammonium ions stimulate utilization of both sugars by stimulating uptake mechanisms. |
