黑曲霉单宁酶高活性菌株的诱变选育*

以黑曲霉（Ａｓｐｅｒｇｉｌｌｕｓ ｎｈｉｇｅｒ）Ｎｏ．１３为出发菌株，经紫外线诱变处理，获得一株制备原生质体的起始菌，该菌株单宁酶活性比Ｎｏ．１３提高５５％，并对其制备原生质体的条件进行了研究，在优化方案基础上，紫外诱变原生质体，诱变株经筛选，最后得到一株具有稳定遗传性的单宁酶高活性菌株，在摇瓶培养基中进行生物转化实验，连续传代１０次，结果显示发酵液中没食子酸浓度始 维持在２２．８－２３．９ｍｇ／

Mutation Breeding of High Tannase Activity Strains from Aspergillus niger

As a original strain, Aspergillus niger No. 13 was mutated by UV treatment. One strain was obtained from mutants.It could act as beginning strain to produce protoplasts. Tannase activity of this strain increased by 55%. And its conditions of producing protoplasts were studied. Based on the optimal program,the protoplasts were mutated by UV. Finnally,one strain which was with high tannase activity and stable genetic property was acquired from mutants by means of screening. The strain was inoculated in the shake flask meida to make the biotransformation experiments. In the situation of ten times continuous transfer of culture, the result showed that the gallic acid concentration in the broth ranged from 22.8mg/mL Its 23.9mg/mL. Its tannase activity (or ability of biotransformation ) was about twice as many as that of strain No. 13.