^(60)Co-γ辐射诱变对康氏木霉产纤维素酶的影响

Effect of ^(60)Co γ-irradiation on Production of Cellulase from Trichoderma knoningii

为了研究不同剂量60Co-γ辐射对康氏木霉产纤维素酶的影响。以康氏木霉AS3.2774为出发菌株,通过0.6~1.8 Gy辐照剂量的60 Co-γ辐射诱变康氏木霉,经平板培养和固体发酵培养筛选出高产菌株,研究不同剂量60Co-γ辐射处理对康氏木霉孢子存活率、康氏木霉产纤维素酶发酵能力和遗传稳定性的影响。结果表明,辐照剂量在0.9~1.1 Gy,康氏木霉孢子致死率达到70.0%~80.0%,辐照剂量大于1.5 Gy时,存活率接近0。辐照处理的孢子经刚果红平板初筛、固体发酵复筛、遗传稳定性试验,获得4株正突变菌株。突变株产纤维素酶活力平均数与出发菌株间存在显著差异,其中菌株Ly-23产纤维素酶的能力平均达0.356 IU/ml,比出发菌株提高了31.8%。该研究为从康氏木霉中筛选纤维素酶高产菌株奠定了基础。

The effect ot ^60 Co-γ-irradiation, with dose 0.6-1.8 Gy,on poducion of cellulase from;Trichodrma knoningii AS3.2774 was studied.The re-sults indicated the death rate of spores reached 70.0% - 80.0% when radiation dosage was 0.9 - 1.1 Gy. After irradiation, the swains were screened first- ly by congo red plate;then solid fermentation, and finally experiment in th estability of genetic transfer of cellulase production. It was showed 4 positive mu-tants had significant difference comparative to the original with paired samples test （t-test） .The filter paper activity of eellulase of swain Ly-23 reached 0.356 IU/ml,with 1.8% enhanced,compared with initial strain.