【摘要】 目的:米曲霉木聚糖酶生产菌的理性选育及发酵优化。方法:以米曲霉FS018为出发菌株,采用紫外和激光诱变先后处理3代,以抗高浓度葡萄糖阻遏效应为筛选模型获得一株高产木聚糖酶菌株FST036,并对该菌株的发酵培养基进行了初步优化。结果:突变株FST036产酶水平可达4200.57U/mL,产酶水平比出发菌株提高了24%。对该菌株的发酵培养基初步优化结果表明:培养基的最适氮源为牛肉膏;最适碳源为麸皮与玉米芯组合,总浓度为4%,二者最适比例为7∶3;对该菌株的发酵条件初步优化结果表明:最适接种量1%,初始pH6.78,250mL三角瓶装液量为45mL,培养72h酶活可达5404.24U/mL。结论:反复多次诱变处理,并结合抗高浓度葡萄糖阻遏效应作为一种理性筛选模型,为通过诱变育种来获得曲霉木聚糖酶高产菌株提供了一条有效的途径。更多还原

【Abstract】 Objective:To screen high xylanase producing strains from Aspergillus oryzae and optimize the fermentation conditions.Method:Aspergillus oryzae FST036 with high production xylanase was breeded from original strain FS018 through UV and laser mutation combined with glucose-resistant screening model.The optimal fermentation conditions of this strain were also studied.Result:Through the mutation,the activity of the mutant FST036 reached 4 243.59U/mL,24 percent more than the FS018’s.The optimum nitrogen was beef extract,the optimum carbon was bran and corncob,the concentration was 4%,the ratio of the bran to corncob was 7∶3;the optimum dose of inoculation was 1%,45mL medium were filled in 250mL flask ;the optimum initial pH was 6.78.At last when cultivated for 72 hours,its xylanase production reached 5404.24U/mL.Conclusion:Multiple mutation combined with glucose-resistant effect as a model proved to be a very effective way of screening high xylanase-producing strains from Aspergillus oryzae.更多还原