单宁酸酶产生菌氮离子注入的诱变效应研究

Study on Mutagenic Effects of Tannase-producing Strain with Nitrogen Ions Implantation

研究了单宁酸酶高产菌株的选育以及低能N+ 离子注入黑曲霉 970 1 (Aspergillusniger 970 1 )的诱变效应。实验结果表明 ,离子注入具有较高的正突变率和较大的变异幅度 ,分别为 2 7 6 1 %和 1 9 35 %～ 48 35 % ,而紫外诱变的正突变率只有 7 6 0 % ;ESR(顺磁共振 )研究表明 ,不论黑曲霉孢子是否经过离子注入 ,孢子内都存在自由基产物 ,但注入后的孢子都产生了较强的自由基波谱单一峰 ,且随注入剂量的增加 ,自由基产额也增加 ,同时 ,孢子存活率的测定结果表现出了“马鞍形”的剂量存活效应曲线 ;扫描电镜观察表明 ,未经注入的孢子较为完整 ,而经注入后的孢子则有明显的刻蚀损伤和破壁现象。剂量越大 ,损伤也越大。以离子注入能量为 1 0keV ,剂量为 3× 1 0 15 N+ /cm2 的注入条件 ,获得一株产酶活为 34 5 0mol/s的高产菌株 ,比原始菌株酶活力提高了 2 6 8倍 ,且酶活性稳定。

The screening of high tannase producer and mutagenic effects of Aspergillus niger 9701 with low N + ions implantation were studied.The results showed that the mutagenic method had high rate of positive mutation and wide range of variance,the value was 27 61% and 19 35%～48 38% respectively, while the rate of positive mutation of UV was 7 60%.Free radicals which were measured by using ESR spectrometer had existed in spores, but the spores with low N + ions implantation produced stronger singal of ESR spectrum than the control The yields of free radicals increased with added implantation dose, and the dose rate of survival and death yield curve showed the special “saddle shape'. The damage of ionic etching and phenomenon of splitting cell wall could be seen from photos by SEM. A high yield tannase strain was screened from Aspergillus niger 9701 at the conditions of implantation energy 10keV and dose 3×10 15 N +/cm 2, its activity of enzyme was 34 50?mol/s by 2 68 times than the initial