【摘要】 以自主筛选的Klebsilla pneumoniaeXJ-Li为甘油脱水酶酶源,研究了其催化反应特性和稳定性。结果表明,甘油脱水酶的最适催化反应温度和pH分别为40℃和8.0。温度在40℃以下,pH处于6.0~8.0之间时酶的稳定性较好。在常见金属离子中,Mg2+和Mn2+对甘油脱水酶的催化反应具有一定促进作用,而Ca2+、Co2+、Fe3+、Zn2+和Cu2+对其活性均有抑制作用。此酶对甘油的最高耐受反应浓度在0.15mol/L左右,对1,2-丙二醇的饱和浓度在0.3 mol/L左右,以甘油和1,2-丙二醇为底物时的反应动力学常数Km值分别5.57mmol/L和8.16mmol/L。更多还原

【Abstract】 The reaction characteristics and stabilization of glycerol dehydratase from Klebsilla pneumoniae XJ-Li was studied.The results indicated that the optimum reaction temperature is 40℃ and the enzyme hold below 40℃ is relatively steady.The enzyme activity is higher when reaction pH is between 6.0 and 8.0,and the remains enzyme activity could maintain 80% after 12 hours in solutions of pH 6.0 to 8.0.In all of metal ions tested,Mg2+ and Mn2+ are favorable to catalyze reaction of glycerol dehydratase,but Ca2+、Co2+、Fe3+、Zn2+ and Cu2+ inhibit the activity of glycerol dehydratase.The highest concentration of glycerol about 0.15mol/L is resistant for the enzyme and the saturated concentration for 1,2-propanediol is around 0.3 mol/L.It is also displayed that the activation energy for catalyzing reaction of enzyme is 18.904kJ/mol,and the Km value is 5.57mmol/L and 8.16mmol/L while glycerol and 1,2-propanediol as substrate,respectively.更多还原