50%甘油溶液。Yeast Supplied in 50%glycerol Containing four tightly bound zinc atoms per molecule.The optimum pH for the enzyme oxidation of ethanol is 8.6-9.0 and is closer to 7.0 for reduction of acetaldehyde.2×Crystallized.One unit reduces one micromole of NAD per minute at 25℃,pH8.8.