大豆异黄酮β-葡萄糖苷酶产生菌的选育及产酶条件研究

Breeding of β-glucosaccharase of soybean isoflavones hyperproducer and studing on culture conditions

以豆豉为材料筛选产大豆异黄酮β-葡萄糖苷酶的菌株,并用京尼平甙法检测相对酶活。以相对酶活最高的野生菌为出发菌(经镜检为杆菌),通过UV和LiCl诱变育种,利用单因素和正交实验进行产酶条件研究确定最佳条件为:黄豆粉1%、酵母膏1%、麸皮2%、KH2PO40.1%、NaCl0.5%、起始pH值7.5、装液量30ml、发酵时间48h、发酵温度37℃、转速70r/min。在该条件下,用京尼平甙法测得该菌株的相对酶活为0.826,水杨苷法测得绝对酶活为5.49μg/ml。

The microorganism which secreted an enzyme named β-glucosaccharase of soybean isoflavones was separated from the lobster sauces. The strain was a bacilli, which was cheked the best deniposide enzyme activity in all. The initial strain was subjected to successive treatment of UV and LiCl irradiation and its medium ingredients and fermentation conditions were optimized by snigle factor and orthogonal experiments. The optimum conditions were： bean powder 1%,yeast cream 1% ,bran 2%, KH2PO4 0.1%, NaCl0.5%, 30ml （300ml erlenmeyer flask）, min, for 48 hours. Under the optimal conditions, the der salicin enzyme activity was 5.49μg/ml. 37℃, initial pH at 7.5, poside enzyme activity rotate speed at 70r/ was 0.826 and the salicin enzyme activity was 5.49μg/ml.