产漆酶菌株的筛选及其对烟秆降解效果的研究

摘要 目的：为烤烟秸秆中木质素降解提供理论依据，丰富降解木质素的真菌资源。方法：从腐殖质中分离高产漆酶的木质素降解真菌1株，对其进行形态学鉴定，并对其液态发酵产漆酶培养条件进行优化和对碳、氮源和CU2+进行正交试验，最后测定了该株菌对烤烟秸秆的降解情况。结果表明(1) 该株真菌形态学鉴定为半知菌亚门，粘头霉属(Moniliales .Gliocephalia sp .)命名为Z-1。基础培养基中产漆酶的最大值出现在液态发酵第4 d，酶活为2.72U/ml;(2) 单因素实验中Z-1最适宜产酶发酵条件为：麦芽糖25g/L 、酵母膏10g/L 、Cu2+ 浓度2.5（mmol/l)，(3)正交试验中，培养基麦芽糖30g/L、酵母膏12g/L、Cu2+ 浓度2.5（mmol/l)处理产酶最高，酶活为3.24U/ml，较基础培养基中高出18.89%；(4)液态发酵菌株对烟秆粉末降解30d后,失重率50%、木质素降解率39.39%、纤维素降解率36%。结论：该株真菌产酶较高，对烤烟秸秆降解能力较强。

High Yield Laccase Producing Strains Screened and the Study of Tobacco Stem Degradation Affected by the Strains

Abstract In order to provide a basis theoretical for tobacco stem lignin degadation and rich the lignin degradation fungi resourcees . This experiment isolated one laccase high yield strain fungi from humus. On the morphological identification, its liquid fermentation culture conditions optimized, orthogonal experiment about carbon, nitrogen source and Cu2+ was carried out, final determination a result that the fungi degradate flue-cured tobacco straw. The results were as follows: (1) the fungi belong to the Moniliales.Gliocephalis.sp. the fungi can produce high quantity laccase up to 2.72 U/mL on 4 days on liquid fermentation culture. (2)The optimal conditions for laccase production by the means of single factors method and orthogonal method. Optimized components of medium was as followed: malt sugar 30 g/L, yeast extract 12 g/L, the concentration of Cu2 + 2.5 mmol/L, the highest yield laccase up to 3.24 U/mL compare with the basica laccase production condition higher 18.8%. (3) Weight lessness rate 50%, lignin degradation rate was 39.39%, cellulose degradation rate was 39.39% after the degradation for the flue-cured tobacco straw powder 30 days. The fungni enzyme production was higher and the ability to degradation tobacco stem was strong.