雀稗麦角菌原生质体诱变育种及发酵条件研究

为获得麦角碱高产菌株，提高雀稗麦角菌（Claviceps paspali strain 3103）发酵的产碱率，用溶壁酶水解处理菌丝体、不同浓度的亚硝基胍诱变处理制备的原生质体，经再生培养获得诱变菌株，再经紫外初筛后进行发酵复筛，采用Van—Urk方法测定产碱量。筛选得到的高产菌株进行二级发酵并优化其发酵条件。实验结果表明，经亚硝基胍诱变处理，麦角总碱的产率由90mg／L提高到了1600mg／L，增加了约16倍；单位产碱率由22．5mg／L／g提高到了400mg／L／g，增加了约17倍；连续传代培养可以得到稳定的高产菌株，接种量为20％时可有效缩短发酵周期。结果表明，用亚硝基胍对原生质体进行诱变处理可有效提高C．papspali的产碱率。

Protoplast mutagenesis of Claviceps paspali and optimization of fermentation conditions

The strain of Claviceps paspali producing higher yield of ergot alkaloids was obtained through protoplast mutagensis, in which the mycelium of Claviceps paspali was first treated by lywallzyme and the different concentrations of the nitrosoguanidine, and the stable mutants was obtained after the primary screen of UV and second screen of fermentation.The productivity of ergot alkaloids was measured by the method of Van-Urk.The results showed that the productivity of ergot alkaloids was increased by 16 folds (from 90mg/L to 1600mg/L) and the unit productivity of ergot alkaloids was increased by 17 folds ( from 22.5mg/L/g to 400mg/L/g).Inoculum of 20% could short the period of fermentation.These results indicated that the protoplast nitrosoguanidine mutagenesis was a feasible approach to increase the productivity of lysergic amide by the C.papspali strain.