Preparation method of D-psicose

The invention relates to the technical field of biology, in particular to a preparation method of D-psicose, which comprises the following steps: (1) taking D-fructose as a substrate, adding a solvent and a first whole-cell catalyst, adjusting the pH value of a reaction system to be weakly acidic, controlling the temperature of the reaction system, and reacting for 2-4 hours to obtain D-psicose; after the reaction is finished, centrifugally collecting supernate, namely a D-allicin alcohol solution; and (2) taking the D-alliinol solution in the step (1), adjusting the pH value to be neutral, adding a second whole-cell catalyst in a ventilating and stirring state, and reacting to obtain the psicose solution. By adopting the method, the conversion rate of the D-fructose to the D-psicose is greatly improved. 本发明涉及生物技术领域，具体涉及一种D-阿洛酮糖的制备方法，该制备方法包括以下步骤：(1)以D-果糖为底物，加入溶剂和第一全细胞催化剂，调整反应体系的pH为弱酸性，控制反应体系的温度，待反应结束后离心收集的上清液即为D-蒜糖醇溶液；(2)取步骤(1)中的D-蒜糖醇溶液，调pH至中性，在通风、搅拌状态下再加入第二全细胞催化剂，反应结束后得到阿洛酮糖溶液。采用上述方法大大提高了D-果糖向D-阿洛酮糖的转化率。