The invention discloses a method for producing
potassium gluconate through
fermentation of
Aspergillus niger, which comprises the following steps: performing one-step jet on
starch and
starch-containing materials, and performing double-
enzyme glucose preparation; using an
Aspergillus niger P1205X21 strain which is resistant to high-concentration K<+> to ferment the glucose solution, and feeding an
ion membrane KOH solution in the
fermentation process to obtain a
potassium gluconate solution; and by using a
thermal crystallization process of multiple-effect continuous
evaporation and
crystallization, directly evaporating and crystallizing in a multiple-effect
evaporation crystallizer to obtain the
potassium gluconate finished product. The invention has the advantages that the raw materials are rich and accessible, the cost is low, the
fermentation product is simplex, the product quality is high and easy to control, no waste water and
waste gas are generated, no
calcium gluconate
mother liquor and
calcium sulfate waste are generated, the environmental
pollution is greatly reduced, the process
route is short,
evaporation,
crystallization,
drying and other procedures during
calcium gluconate preparation are reduced, vapor is saved, the
power consumption is reduced, and the production cost is greatly lowered.