The invention relates to a preparation method of high-density
yeast fermentation liquor. The method comprises the following steps: performing size mixing on corn,
soybean meal and water, respectivelyadding high-temperature
amylase, glucoamylase and acidic
protein for thorough enzymolysis, and carrying out
solid-liquid separation to obtain
solid wet residues and a diluted composite
nutrient solution; diluting a part of the diluted composite
nutrient solution, inoculating the diluted solution with a
yeast seed solution for culturing, and carrying out reduced-pressure
evaporation on the residualdiluted composite
nutrient solution to obtain a concentrated solution; and in the culture process, controlling sufficient dissolved
oxygen in a fed-batch manner of the concentrated composite nutrientsolution and nutritive salt, stopping feeding when the
yeast density is maximum, acquiring
yeast fermentation liquor when the
fermentable sugar is used up, and performing standing to obtain high-density yeast liquid. According to the invention, different
enzyme preparations are used for enzymolysis to obtain
sugar and
amino acid required by yeast growth, and the high-density yeast liquid is obtained in a continuous fed-
batch fermentation and batch
discharge manner, so that the yeast content is increased, the
fermentation and sterilization steam consumption is small, the production
water consumption is low, the
discharge amount of tank washing
wastewater for a
fermentation tank is reduced, and the effects of
energy conservation, consumption reduction and clean production are achieved.