复合诱变黑曲霉选育β-葡萄糖苷酶高产菌株

SELECTION OF HIGH-YIELD β－GLUCOSIDASE PRODUCINGSTRAIN BY COMPLEX MUTAGENESIS OF ASPERGILLUS NIGER

对黑曲霉原生质体进行紫外、ＬｉＣｌ复合诱变，观察诱变后原生质体再生菌落，发现了抱子颜色变异较大的菌株，且其变化与酶产量相关。经发酵筛选，获得卜葡萄糖昔酶活较高菌株，其酶活由出发菌株的１０ｕ／ｍｌ提高到１４．７ｕ／ｍｌ。再对高产突变株进行氮离子注入，酶活又提高２０％（达１７ｕ／ｍｌ）。

The protoplasts of Aspergillus niger prepared under the optimum conditions were treated by UVirradiation and LiCl. The results showed that some mutants were different from the original strains in sporecolour which related to the ability of producing β-glucosidase. The high-yielding strains was obtained byfermentation screening of many regenerative mutants. The arhvity of β－glucosidase were increased to 14.7u / mlfrom 10u / ml. Nitrogen ion treatment of the mutants resulted in a further increase of 20% in β-glucosidaseactivity.