黑曲霉的紫外诱变及酸性蛋白酶缺陷株的选育

Mutagenesis and Screening of Mutant of Aspergillus niger Deficient in Acid Protease

以黑曲霉3.2130为出发菌株,经紫外线诱变处理,采用平板培养筛选,获得一酸性蛋白酶缺陷的菌株L4。通过对紫外照射时间、照射距离、孢子悬液稀释倍数的影响分析,得出最佳诱变条件,即照射时间180 s,照射距离30 cm,孢子液中孢子数量约为109个/L。该株的酸性蛋白酶活性为原始菌株的3.7%,而其β-葡萄糖苷酶活性基本不变,可作为外源基因高效分泌表达的宿主菌。

A mutant of Aspergillus niger 3. 2130 ,deficient in acid protease expression, have been isolated after in vivro UV-mutagenesis of conidiospores and selected by halo-screening on the gelatin/casein plate. According to the study of mutagenesis condition,its optimum condition was found. Acid protease activities of 3. 2130-L4 was 3.7% of the parental strain and β-glucosidase activity was mainly normal. This strain may be used as the host for efficient expression of foreign proteins.