高活力碱性淀粉酶菌种的选育及培养条件研究

SELECTION OF HIGH ALKALINE AMYLASE PRODUCTION AND ITS FERMENTATION CONDITIONS

通过对产碱性淀粉酶芽胞杆菌Ｂ－９５４５进行紫外线、原生质体亚硝基胍复合诱变等反复处理，获得一株具有较高碱性淀粉酶活力的变异株ＰＮ－６。产酶活力从５４０ｕ／ｍｌ提高到７８０ｕ／ｍｌ，确定的最佳培养条件是：ｐＨ８－１０，３０℃培养４８ｈ。从变异株和出发菌株的生长及产酶曲线看到，变异株的生长速度低于出发菌株，其产酶高峰与出发菌株相比略拖后一段时间，但是酶活力要远大于出发菌株。

By repeated treatment with UV,MNNG to protoplast a mutant PN-6with high alkaline amylase adtiyity was obtained from Bacillus megaterium B-9545.The enzyme actiyity was improved froal 540u/ml to.780./ml.The optimum condition.s for enzyme production are PH8.0-10. 0 , cultivating 48 hours at 30℃.From the growth. and enzyme productioncurves,it can be seen that the growth of the mutant is lower and the maximum.phase of enzyme production is more laggard than. those of initial strain,but the enzyme activity is far greater than that of parent strain.