重离子辐照诱变黑曲霉产纤维素酶菌株的筛选

为提高黑曲霉(=AS3.316)产纤维素酶的活力,用20、40、60、80、100、120、140Gy剂量的重离子束对其进行辐照诱变,并通过初筛、复筛筛选出了纤维素酶活力提高的菌株.结果表明:通过重离子束辐照共筛选出了5株突变体T2-1、T3-1、T5-1、T6-3、T6-4,其中突变体T6-4的纤维素酶活力最高,滤纸酶、纤维素内切酶、纤维素外切酶、β-葡萄糖苷酶活力分别为:61.3、116.2、29.9、35.9U/mL,与初始菌株相比纤维素酶活力分别提高了3.0、3.78、2.76和2.52倍;其余突变体纤维素酶活力大小依次为T6-3>T5-1>T3-1>T2-1;120Gy辐照条件下,诱变效果最为显著;经9代传代稳定性试验,5株突变体在传代过程中虽有不同程度的变化,但总体表现相对稳定.

Using heavy-ion mutagenesis technology to select cellulose enzyme vitality of mutants of Aspergillium niger

In order to improve the cellulose enzyme vitality of Aspergillus niger(=AS3.316),heavy-ion beam at 20,40,60,80,100,120 Gy and 140 Gy doses was used for inducing mutation.Higher cellulose enzyme vitality strains were screened through the primary screening and secondary screening.The result showed that 5 mutants T2-1,T3-1,T5-1,T6-3,T6-4 were selected,and T6-4 had the highest cellulose enzyme activity.The activity of filter paper cellulose enzyme,endo-glucanase,exo-glucanase and β-glucosidase of T6-4 was 61.3,116.2,29.9 U/mL and 35.9 U/mL respectively.Compared with the original A.niger(=AS3.316),the cellulose enzyme activity was increased by 3.5,3.78,2.76 and 2.52 times in turn.The activity of cellulose enzyme of the rest mutants sorted from strong to the weak were T6-3>T5-1>T3-1>T2-1.The dose at 120 Gy showed the best mutagenesis effect.Mutants had different degree of changes in the genetic stability,but overall,the performance showed relatively stable.