白腐菌紫外诱变选育高产漆酶突变株及其产酶条件研究

Breeding of producing high yield of laccase strains by UV mutation

以白腐菌为出发菌株,利用紫外线(UV)进行诱变,筛选高产漆酶突变菌株。通过测定致死率绘制出发菌株的致死曲线,采用PDA-RBBR平板变色法进行初筛,ABTS检测酶活对突变株进行摇瓶复筛。结果表明:利用15 w紫外灯在照射距离为30 cm,照射时间为120 s,致死率为72.1%的条件下进行诱变处理,获得一株高产菌株,其酶活提高79.54%,经过5代传代培养,未见酶活下降,具有较好的遗传稳定性,进一步研究了初始pH值,接种量和培养基装液量等对诱变菌株产酶的影响,结果表明在最佳的培养条件pH值6.0,15%的装液量于28℃下,酶活达214.9 U/L。

The UV was applied as mutagenesis to screen mutant of high yield of laccase from white rot fungi. The high yield mutant was identified by RBBR-containing PDA plates, and activity was measured to rescreen by ABTS. The results indicated that the mutant was screened out when the UV lamp was 15w, the irradiation distance was 30 cm and the irradiation time was 120 s. A mutant with high yield of laccase was obtained. The activity was increased 79.54% compared with that of wild strain. After 5 generations, the mutant strain still had excellent genetic stability. The optimum culture conditions were as follows the pH was 6, the culture temperature was 28℃ and liquid volume was 15%. Under the condition, the activity of enzyme was 214. 9U/L.