Abstract: The isomerization of D-fructose by D-psicose 3-epimerase (DPE) is the most economical and environmentally friendly way to prepare D-psicose. However, the poor storage stability of DPE limits its industrial application. Clostridium cellulolyticum DPE (CcDPE) was used as the research object to find a green, efficient, low-cost storage stabilizer that does not affect the subsequent enzymatic reaction. The effects of stabilizers such as carbohydrate, metal ions and polyols on the storage effect of CcDPE and the subsequent enzymatic reaction were investigated. First, single factor experiment was carried out, and then the two most suitable stabilizers were compounded. The results showed that glycerol and Co2+ could significantly improve the storage stability of CcDPE crude enzyme solution, and did not have a negative impact on the subsequent enzymatic conversion reaction. At 25 ℃, 1 mmol/L Co2+ could prolong the half-life of crude enzyme from 4.5 d to 46 d. 30% glycerol could prolong the half-life to 33 d; the combination of 20% glycerol and 0.5 mmol/L Co2+ could prolong the half-life to 80 d. The results provide technical support for further industrial application of CcDPE.
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2021, Vol. 47 
