产糖化酶根霉菌的分离及其酶学性质研究

从五粮液酒厂周边采集土样中分离出6株产糖化酶且酶活较高的菌株,选取酶活最高的1株K-1为出发菌,进行发酵实验和酶学性质研究,结果表明,糖化酶酶活在50～55℃较高,最适作用温度为55℃;糖化酶在pH5.5～6之间酶活力较高。酶对玉米粉、小麦粉、木薯粉、苦荞粉、黄豆粉有较强的液化能力,其中对玉米粉的糖化能力最强。在酶的动力学实验中测得Km=1.446 mg/mL,Vm=0.269 mg/mL.min。

Isolation of Glucoamylase-producing Rhizopus Strains and Study on Their Enzyme Properties

6 Rhizopus strains producing glucoamylase with high enzyme activity were isolated from that were isolated from soil samples collected from arroundings of Wuliangye Distillery.Strain K-1 with the highest enzyme activity was used as starting strain for fermentation experiments and enzyme properties research.The results showed that glucoamylase displayed the highest enzyme activity both at 50～55 ℃(the optimum temperature was at 55 ℃) and pH value was 5.5～6.Glucoamylase could liquefy corn flour,wheat flour,tapioca starch,buckwheat powder,and soybean meal,and it could saccharify corn flour easily.The kinetics experiment of glucoamylase showed Km = 1.446 mg/mL and Vm = 0.269 mg/mL·min.