High-temperature-resistant D-psicose 3-epimerase and application thereof

The invention relates to the technical field of enzyme engineering, in particular to high-temperature-resistant D-psicose 3-epimerase and application of the high-temperature-resistant D-psicose 3-epimerase, and the amino acid sequence of the high-temperature-resistant D-psicose 3-epimerase is shown as SEQ ID NO.5 or SEQ ID NO.7. The invention further relates to a preparation method of the high-temperature-resistant D-psicose 3-epimerase. The optimal temperature of the D-psicose 3-epimerase TsDAE2 is 85 DEG C, the half-life period of the D-psicose 3-epimerase TsDAE2 at 80 DEG C is longer than 11 h, and the thermocatalytic performance of the D-psicose 3-epimerase TsDAE2 is obviously superior to that of similar enzymes reported at present. The optimal pH of the D-psicose 3-epimerase TsDAE2 is 5.5, the D-psicose 3-epimerase TsDAE2 is coupled with thermophilic glucose isomerase to catalyze 500g/L glucose isomerization under the acidic condition to prepare D-psicose, when the reaction reaches balance, the final con