【作者】 李宁； 贾英民； 祝彦忠；

【Author】 Li Ning Jia Yingmin Zhu Yanzhong (School of Food Science and Technology,Agricultural University of He Bei,Baoding 071001)

【机构】 河北农业大学食品科技学院；

【摘要】 为诱变选育出产高温乳糖酶的高产黑曲霉(Aspergillus niger)菌株,采用紫外线诱变和 Co60-γ射线诱变协同的方法,对出发菌株 D2-26进行诱变处理,并根据致死率与诱变剂量的相互关系,选择合适的诱变剂量。确定了菌株的最佳诱变剂量,即采用15 min 紫外线照射,用剂量为2 kGy 的γ射线对黑曲霉 D2-26进行诱变,获得1株产高温乳糖酶的高产突变株(A．niger UCO-3)。对其进行显微观察发现,突变株菌落形态较原菌株略有改变, 菌落呈整齐圆形年轮状,菌落背面只在接种处有明显的皱褶。突变株产乳糖酶能力显著提高, 酶活力可达16．27 U/mL。紫外线和 Co60-γ射线的协同诱变效果好,突变株稳定性和产酶情况良好。更多还原

【Abstract】 In order to screen the high-yielding strain which produces the thermostable Laetase from Aspergillus niger by induced breeding.The original strain D2-26 was treated with the cooperation of UV and γ rays.According to the interaction of lethal rate and radiation dose,the optimum condition was made.The optimum dose was determined.A.niger UCo-3,a lactase-yielding mutant strain was obtained by induced breeding of strain D2-26,which was treated with 15 min UV and following 2 kGy γ rays.The regularly ring-shaped colony of the strain UCo-3 was somewhat different from that of its parents.The center of back colony has the obvious fold.The β-galactosidase activity of UCo-3 was 16.27 U/mL,which was higher than that of strain D2-26.The cooperative effect of UV and γ rays was perfect.The result of this experiment showed that the mutant strain was stable and high lactase yield.更多还原