【作者】 邵喜霞；

【导师】 张力；

【作者基本信息】 甘肃农业大学 ， 动物营养与饲料科学， 2009， 硕士

【摘要】 试验利用不同种类的碳源、氮源对绿色木霉ZJ纤维素酶诱导合成的影响进行了研究,并以绿色木霉ZJ为出发菌株,利用紫外线诱变、硫酸二乙酯诱变和DES-紫外线复合诱变三种诱变剂对出发菌株绿色木霉ZJ进行处理,筛选纤维素酶高产菌株。最后试验采用菌种——绿色木霉(Trichoderma vivid)ZJ、变色栓菌(Trametes versicolor)、糙皮侧耳菌(Pleurotus ostreatus)等产纤维素酶和产木质素酶菌株进行组合,为稻草秸秆的降解提供依据。试验结果表明:1.结构比较完整的纤维类物质作为碳源时对纤维素酶的产生具有较强的诱导作用;接种后3~4 d收获绿色木霉ZJ株培养物可获得最大产酶量;以1% (NH4)2SO4和2%酵母膏组成的复合氮源在菌株的生长和诱导产酶方面均比单一氮源要好。2.利用紫外线诱变、硫酸二乙酯诱变和DES-紫外线复合诱变三种诱变剂对出发菌株绿色木霉ZJ进行处理,结果表明三种诱变方法中以DES-紫外线复合诱变的效果最佳,正突变率最高,负突变率最低。最后筛选出一株纤维素酶产酶量高且性状稳定的高产菌株L4C,其CMC酶活和滤纸酶活较出发菌株分别提高了122.13、124.51倍。3.用稻草秸秆为基质进行单菌一菌种和混菌发酵,实验表明,对于木质素的降解绿色木霉ZJ和诱变菌株L4C的效果不及其他,而混菌发酵又较单独的白腐真菌发酵降解效果好;混菌发酵对纤维素的降解效果最好,其中以糙皮侧耳菌+L4C组合为佳,对中性洗涤纤维、酸性洗涤纤维、木质素,纤维素的降解率分别为16.96%,23.77%,42.99%,27.21%,均高于其他组合。更多还原

【Abstract】 To determine the best culture time and inducer for the biosynthesis of cellulase by Trichoderma vivid and thus provide the conditions for its practical application.Making use of the three mutagens of ultraviolet ray,DES and DES-UV to selection of cellulase high-yield strains. In the trial, the test by producing cellulase and ligninolytic enzymes combined to degradation of straw.The experiment takes the following microbiology as resources: Trichoderma vivid ZJ,Trametes versicolor,Pleurotus ostreatus.The results indicated that:1. The results showed that: The largest enzyme yield should be obtained after 3–4 d post the inoculation of Trichoderma viride ZJ strain. With cellulose powder as a carbon source and the complex substance composed of ammonium sulfate and yeast extract as a nitrogen source, Trichoderma viride has the highest enzyme activity.2. Making use of the three mutagens of ultraviolet ray,DES and DES-UV to selection of cellulase high-yield strains. The results showed that DES-UV mutagenesis is the best of the three mutagens. A stable,high-yield cellulase -producing strain can be screened,named L4C.Under the optimum conditions,the highest enzyme activities of CMC and FPA was 122.13 and 124.51 higher than that of initial strain.3. Rice straw as a substrate with a single strain and mixed fermentation.The experiments showed that the mixed fermentation is the best method to degradation of cellulose.And the combination of Pleurotus ostreatus + L4C is the best combination to degradation of straw.For the degradation of lignin,Trichoderma vivid ZJ and L4C is worse than those of others,and mixed strains decomposition of lignin is better than separate strain fermentation by white-rot fungi.更多还原