混合菌对玉米秸秆水解糖化的影响

发布时间：2018-03-05 03:40

  本文选题：玉米秸秆　切入点：预处理　出处：《沈阳农业大学》2017年硕士论文　论文类型：学位论文

【摘要】：能源、资源、环境问题已成为制约社会经济可持续发展的主要障碍,开发新的可持续的绿色替代能源和资源已成为全球的紧迫任务,利用木质纤维素生产燃料乙醇,因其洁净、环保和安全等优点,成为人们研究的热点。利用木质纤维素生产燃料乙醇,包括糖化过程和乙醇发酵过程,其中木质纤维的预处理糖化过程是燃料乙醇生产过程中最重要的一环。本研究首先以玉米秸秆为供试材料,比较了四种不同预处理方法对玉米秸秆降解糖化过程的影响,这四种预处理方法分别为挤压膨化与绿色木霉相结合预处理法、稀硫酸与绿色木霉相结合预处理法、杂色云芝/糙皮侧耳与绿色木霉相结合预处理法及与单独的绿色木霉处理法。通过玉米秸秆预处理试验,以还原糖得率为主,确定了合适的玉米秸秆预处理方法。其次,研究了杂色云芝和糙皮侧耳不同体积的混合配比对玉米秸秆降解效果的影响,并对杂色云芝/糙皮侧耳最佳混配比时酶活随时间的变化进行了探讨。最后,以酶解温度、混合菌添加量、初始pH值和玉米秸秆粒径为试验因素,考察了不同工艺条件下玉米秸秆降解过程中还原糖得率、纤维素降解率、半纤维素降解率和木质素的降解率。得到的结论如下:(1)采用杂色云芝/糙皮侧耳与绿色木霉相结合预处理法,在降解玉米秸秆过程中还原糖得率优于挤压膨化与绿色木霉相结合预处理法、稀硫酸与绿色木霉相结合预处理法及单独的绿色木霉处理法。(2)杂色云芝/糙皮侧耳按体积比1:1混合时,在降解玉米秸秆过程中还原糖得率较其他混合比例稍高。(3)杂色云芝/糙皮侧耳等体积比混合时,漆酶(Lac)在培养10d时酶活最高,为2102U/L,过氧化物酶(Lip)在培养19d时最高,为215U/L。(4)通过正交旋转试验,明确了在温度为28.9℃,pH值为5.3,混合菌添加量为31.9mL/L,秸秆粒径为75目的条件下,玉米秸秆水解糖化时还原糖的得率最佳,还原糖得糖率为28.6%。通过本试验,不但为平菇生产中剩余物的回收利用提供了有效途径,而且也为玉米秸秆水解糖化生产燃料乙醇提供了 一定的参考。
[Abstract]:Energy, resources and the environment have become major obstacles to sustainable socio-economic development, and the development of new and sustainable green alternative sources of energy and resources has become an urgent global task, using lignocellulose to produce fuel ethanol because of its cleanliness, The advantages of environmental protection and safety have become the focus of research. Using lignocellulose to produce fuel ethanol, including saccharification process and ethanol fermentation process, The pretreatment and saccharification of wood fiber is the most important part in the process of fuel ethanol production. Firstly, the effects of four different pretreatment methods on the degradation and saccharification of corn straw were compared. The four pretreatment methods are extrusion expansion combined with green Trichoderma and dilute sulfuric acid combined with green Trichoderma. The pretreatment method was combined with Trichoderma viridis and Trichoderma viridis. Through the experiment of corn straw pretreatment, the suitable pretreatment method of corn stalk was determined by reducing sugar yield. In this paper, the effect of mixed ratio of different volume of hybrid lucidum and Pleurotus strigella on the degradation effect of corn straw was studied, and the change of enzyme activity with time in the optimum mixture ratio of the mixed ratio was discussed. Finally, the enzymatic hydrolysis temperature was used. The yield of reducing sugar and the degradation rate of cellulose in the process of corn straw degradation under different conditions were investigated by adding mixed bacteria, initial pH value and grain size of corn straw. The degradation rate of hemicellulose and lignin. The conclusion is as follows: (1) the pretreatment method of hybrid lucidum / Pleurotus strigella combined with Trichoderma viridis was used. The yield of reducing sugar in the degradation of corn straw was superior to the pretreatment method of extrusion and Trichoderma viride. The mixture of dilute sulfuric acid and Trichoderma viridis combined with the pretreatment method of Trichoderma viride and the treatment of Trichoderma viride alone. In the process of degradation of corn straw, the yield of reducing sugar was slightly higher than that of other mixtures. (3) when the volume ratio of mixed variegated lucidum / Pleurotus strigella was mixed, laccase Lacs had the highest enzyme activity at 10 days, which was 2102 U / L, and the peroxidase Lipase was the highest at 19 days. Under the conditions of temperature 28.9 鈩，

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