醋酸杆菌乙醛脱氢酶热稳定剂的筛选

Screening of Thermostabilizer of Aldehyde Dehydrogenase from Acetobacter

研究了不同种类物质对醋酸杆菌产乙醛脱氢酶（ALDH）热稳定性的影响，以期得到酶的最佳热稳定剂配方。蔗糖是最好的热稳定剂，其次是甘氨酸、麦芽糖、硫酸钠、丙氨酸；氯化钾、赖氨酸、天冬氨酸、氯化铝、谷氨酸、氯化钙对ALDH的热稳定性也有一定的提高作用。采用正交试验确定最佳复合热稳定剂配方为：硫酸钠20mmol／L、甘氨酸20mmol／L、麦芽糖25mmol／L、蔗糖0．5mmol／L。复合热稳定剂的添加使ALDH酶活保留率在30℃～55℃温度范围，均有一定程度的提高，55℃保湿30min后，酶活保留率为75％，比对照组高出115％。

In order to get the optimal thermostabilizer formula, effect of different substances on aldehyde dehydrogenase thermostability from acetobacter was studied .The results showed that the optimal thermostabilizer was sucrose; followed by glycine, maltose, sodium sulfate, alanine; potassium chloride, lysine, aspartic acid, aluminium chloride, glutamic acid, calcium chloride all could improve slightly the thermostability of ALDH. The optimal multiplex thermostabilizer formula determined by the orthogoual experiment was as follows： sodium sulfate 20 mmol/L, glycine 20 mmol/L, maltose 25 mmol/L, sucrose 0.5 mmol/L. The residual activity of ALDH containing multiplex thermostabilizer increased at 30 ℃ -55℃, and the residual activity remained 75% at 55℃ for 30 min, which was increased by 115% than that of the control.