为提高D-塔格糖3-差向异构酶(D-tagatose 3-epimeriase,DTE)粗酶液的储存稳定性,在其粗酶液中添加防腐剂以及糖类、盐类、多元醇类与蛋白质等稳定剂。通过单因子研究与正交实验,研究了它们对酶液储存稳定性的影响。结果表明:0.3%尼泊金甲酯(methylparaben,Met)有较佳的防腐效果,且能显著降低酶液的失活速率;果糖、肌醇、Mg SO4是DTE良好的稳定剂,其组合2 mmol/L Mg SO4,6%果糖,4%肌醇为最优的复合稳定剂;将加有0.3%Met和复合稳定剂的粗酶液在25℃下保存,粗酶失活半衰期为62 d,而仅加防腐剂Met的半衰期为25 d,空白酶液仅2 d。因此,复合稳定剂与防腐剂Me的联合使用能较好地提高DTE粗酶液的储存稳定性。

Preservatives,saccharides,sugar,alcohol or polyols,salts,and proteins were added into the enzyme solution to increase the stability of D-tagatose 3-epimerase. The effect of different substances on storage stability of Dtagatose 3-epimerase( DTE) was studied through single factor experiments and orthogonal experiment. The results showed that 0. 3% methylparaben( Met) was effective to control the growth and reproduction of microbes and reduce the losing rate of enzyme activity significantly. Fructose,inositol and Mg SO4 were relatively good stabilizers. The complex stabilizers consist of 2 mmol / L Mg SO4,6% fructose,and 4% inositol. When the enzyme solution containing0. 3% Met and complex stabilizers was stored at 25 ℃,its half-life was 62 days,while its half-life would be 25 days if only 0. 3% Met was added into enzyme solution during storage. The half-life of the control enzyme was only 2 days.Thus complex stabilizers and preservatives were helpful to improve the storage stability of D-tagatose 3-epimerase.