烟梗为原料固态发酵生产果胶酶

摘要

Production of pectinase from tobacco stem by a fungus strain JXY-17 in solid state fermentation was carried out. Single factor and orthogonal experiments were adopted for the optimization of culture media. The results indicated that the influential extent of factors affecting enzyme production by the fungus strain JXY-17 in order was the ratio of the tobacco stem to water (A) > (NH4)2SO4( B) >KH2PO4(D) > Tween-80 (C). The optimum combination for enzyme production was A3B2C2D1, I. E. Ratio of tobacco stem to water was 1:1.5, (NH4)2SO4 5. 0% , Tween-80 0. 10% , KH2PO40. 03% , KH2PO4 0.2%. The optimized fermentation and recovery conditions were the following: the suitable culture medium with the inoculum size of 25 mL, nature pH, 50 g of tobacco stem in 1000 mL triangle flask, fermented at 30 ℃ for 6 days. Under the above conditions, the highest enzyme activity of pectinase reached 8171. 35U/g, a 3. 8-fold increase compared with that of the original conditions. After recovery of pectinase, the residue tobacco stem and the composition of the crude enzyme solution were analyzed. The residue of the fermented tobacco stem could be recovered as cellulose materials. The pectin was reduced by 45% compared with that of the control (tobacco stem). The recovery of the residue tobacco stem was about 50%.%以烟梗为主要原料,采用单因素和正交实验对筛选到的丝状菌JXY-17固态发酵产果胶酶的培养基进行了优化,正交实验结果表明,影响该菌株产果胶酶的因素依次为含水量(料水比)(A)＞(NH4)2SO4(B)＞KH2PO4(D)＞吐温-80(C),产酶培养基组成为A3B2C2D1,即固液比1∶1.5,(NH4)2SO4 5.0％,吐温-80 0.10％,KH2 PO40.20％.采用该固态发酵培养基,自然pH,接种量25 mL,装料量为50 g(干基)/1000 mL三角瓶,30℃恒温培养6d,产酶最高达8171.35U/g干曲,为初始酶活的3.8倍.提取酶液后的残余烟梗还可用于提取烟梗纤维类物质.残余烟梗的化学成分检测结果表明,与原始烟梗(或对照)相比,其果胶质降低了45％左右,残余烟梗固形物回收率约50％.