Preparation method for co-producing D-psicose and sodium gluconate

The invention relates to the technical field of biology, in particular to a preparation method for co-producing D-psicose and sodium gluconate, which comprises the following steps: (1) taking D-fructose and D-glucose as substrates, adding a solvent and a whole-cell catalyst I, adjusting pH and controlling temperature to obtain a mixed solution of D-alliitol and sodium gluconate; (2) taking the supernate, adjusting the pH value to be neutral, adding a whole-cell catalyst II in a ventilating and stirring state, and obtaining a mixed solution after the reaction is finished; (3) taking the mixed solution, enabling the mixed solution to pass through a cation resin column, enabling the collected effluent to pass through an anion resin column, and treating the collected effluent to obtain a psicose product; and washing the anion resin column with a sodium hydroxide solution, and treating the collected effluent to obtain a sodium gluconate product. The two-step multi-enzyme tandem biotransformation system is utilized