冠突散囊菌产阿魏酸酯酶菌株筛选与产酶条件优化

Screening of Eurotium cristatum producing ferulate esterase and optimization of enzyme producing conditions

通过制备、初筛和复筛PDA(potato dextrose agar)平板培养基和液体培养基,从8种不同来源的冠突散囊菌中筛选出1株高产阿魏酸酯酶的优势菌种,并通过控制反应时间、酶添加量和缓冲溶液pH值,对该优势菌种进行条件优化实验,以确定其最佳反应条件。实验结果表明:3株冠突散囊菌(C20G11、C20G10和PDAJ1)在粗筛培养基中的菌落生长速度占据优势;通过复筛,发现PDAJ1菌落生长速度在3株冠突散囊菌中占据优势,由此确定其为优势菌种;当条件优化实验的反应时间为150 min、缓冲溶液pH值为6.0和酶液与阿魏酸甲酯溶液的体积比为3︰1时,PDAJ1产酶活性最大;随着反应时间延长、酶含量增加和缓冲溶液pH值增大,PDAJ1产酶活性逐渐降低。

By preparing PDA plate medium,PDA liquid medium,primary screening medium and double screening medium,one strain with high ferulic acid esterase production was screened out from 8 kinds of different sources of Eurotium cristatum.The optimum reaction conditions of the dominant strain were determined by controlling the reaction time,addition amount of enzyme and pH of buffer solution.The results showed that the colony growth rate of three strains C20G11,C20G10 and PDAJ1 were dominant in coarse screening medium.PDAJ1 was identified as the dominant species by rescreening the colony growth rate of the three strains.The optimization results showed that when the reaction time reached 150 min,the pH of buffer solution was 6.0,and the volume ratio of enzyme solution to methyl ferulate solution was 3︰1,the enzyme production activity of PDAJ1 reached the maximum.Then,with the extension of reaction time,the increase of enzyme content and pH value of buffer solution,the enzyme production activity gradually decreased.