利用原生质体融合技术提高黑曲霉产酶活力的研究

以黑曲霉Ｎ３４３和ＵＶ—１１为出发株，分别经亚硝酸诱变处理，再以制霉菌素浓缩处理，从中筛得３株维生素缺陷型和１株氨基酸缺陷型的突变株。选取来自Ｎ３４３的突变株ＮＢ_３（Ｂ_１^－，ＰＰ^－，ＦＡ^－）和来自ＵＶ—１１的突变株ＵＢＩ（Ｐｒｏ^－）为融合亲本，在研究其原生质体释放和再牛条件的基础上，以ＰＥＧ诱导进行了原生质体融合。用直接选择法检出９８个融合子，经过筛选得到两株稳定的融合子：Ｆ

STUDY ON IMPROVING THE COMPONENT AND ACTIVITIES OF ENZYMES EXCRETED BY ASPERGILLUS NIGER BY MEANS OF PROTOPLAST FUSION

The spores of two prototrophic strains of Aspergillus niger (N343 and UV-11) were treated with sodium nitrite as mutagenic agent, then transferred on Koji medium (CM) for growth of viable spores and their progeny. The progenic spores were concentrated in presence of nystatin. As the result, 3 auxotrophic mutants (NB1, NB2, NB3) from N343 about vitamin and 1 auxotrophic mutant (UB1. Pro-) from UV-11 were gained. Among them, Mutant NB3 (Thi-, PP-, FA-) and UB1 were selected as the fusion parents and fused by help of PEG after the study on factors affecting the preparation and regeneration of their protoplasts. Among 98 fusants which were collected directly from mineral medium, FNU32 and FNU38 were determined as the stable hybrid in gross morphology as well as high strengths of both cellulsae and amylo-glucosiclase activities.