复合诱变及发酵优化选育染料木素转化菌株的研究

Breeding of fungus with high biotransformation for genistein by multi-mutagenizing and compound strain culturing

本研究通过对两株β-葡萄糖苷酶高产菌株黄丝曲霉JS-Q和黑曲霉XK-L进行复合诱变,诱变混合菌株直接进行产酶培养,利用"复杂系统定向调控技术",以酶活为指标对培养条件进行连续的定向调控,在产酶培养条件优化过程中富集正突变株并逐步提高酶活,在挑选出正突变株的同时优化出适合高酶活正突变株的培养条件.最终从优化产酶培养基中挑选到菌株F17和F27,产酶能力比出发前菌株XK-L提高了64.9%和49.4%.用这两株菌分别发酵槐角苷,经测定其转化率分别为76%和78%,比出发菌株XK-L提高31.0%和34.5%.

The compound strains of JS-Q and XK-L were treated by several mutation conditions, and all the mutant strains were mixed together after the treatment. In the process of culturing the unscreened mixture of mutant strains and optimizing the culture medium according to the activity of enzyme, the culture medium tended to fit for the positive strain, and the activity of enzyme was enhanced. After several rounds of culturing and optimizing, both the positive strain with high activity of enzyme and its suitable culture medium were found. As a result, two strains, F17 and F27, were bred from the mixture of mutant strains, whose activity of enzyme were enhanced by 64.9% and 49.4%. And their biotransforrnation percentage on Sophoricoside achieved 76% and 78%, increased by 31.0% and 34.5%.