【作者】 潘锋；

【导师】 汪信； 杨树林；

【作者基本信息】 南京理工大学 ， 化学工程与技术， 2002， 博士

【摘要】 本论文对秸秆生物降解生产单细胞蛋白进行了研究。目的在于通过对可再生资源的生物转化利用，拓广饲料来源，提高饲料质量，在有利于生态平衡的条件下同时解决粮食短缺及环境污染问题，使其作为一种清洁产业促进农业的可持续发展。工作中对微生物纤维素酶发酵条件及酶学性质进行了探讨；研究了混合发酵生产单细胞蛋白的方法，提出了生物降解秸秆生产单细胞蛋白的工艺流程。主要内容如下： 1．探讨了磨碎、稀酸处理、氨水处理等预处理方法对秸秆理化性质的影响，应用X-射线衍射仪、扫描电子电镜(SEM)、红外吸收光谱(IR)对预处理后秸秆分析和表征。结果表明，预处理可以降低纤维素的结晶度、增大秸秆吸附纤维素酶的有效表面积。 2．选用五株真菌进行纤维素酶产酶条件研究，探讨了培养基组分及外界因素对纤维素酶活力的影响。结果表明，五株真菌具有较强的产酶能力及较强的纤维素、半纤维素降解能力；降解产物中含有葡萄糖、木糖、纤维二糖等多种糖组分。 3．纤维素酶是一种诱导酶。葡萄糖的存在对纤维素酶产生非竞争性抑制作用。五株真菌产纤维素酶具有较好的热稳定性和pH稳定性。 4．霉菌混合发酵对提高秸秆蛋白含量的贡献不大；霉菌与酵母混合培养由于二者的互惠共生关系使秸秆蛋白含量有较大提高。产品中蛋白质含量随酵母种类的增加而增大，实验中以四种酵母共发酵蛋白质含量最高，酵母菌不仅可以起去阻遏作用，而且对真菌的生长有正效应。 5．应用多菌种混合发酵法以稻草为底物进行培养，产物中粗蛋白质含量提高261％，达到21.51％，仅次于酵母粉及大豆，而比小麦和玉米高的多。富含16种氨基酸，总和占产物干重的14.31％，其中必需氨基酸含量高于联合国粮农组织(FAO)规定的标准。本工作选用菌株的应用效果优于国外交流菌种。 6．多菌种混合发酵可提高甘蔗渣的蛋白质含量，增大甘蔗渣饲用价值。对拓广饲料来源，提高饲料质量，大力发展畜牧业具有重要意义。更多还原

【Abstract】 Biological degradation of wheat straw to produce Single Cell Protein was studied in this paper. The purpose of the research is to broaden feedstuff source and raise its quality by biologically transforming and utilizing recycled resources. The ultimate objects of this work are to solve the problem of shortage of grain and environmental pollution based on ecological balance and to promote agriculture development continuously as a kind of clean industry. Cellulase fermentation conditions and enzyme properties are discussed. Method of co-fermentation on the production of Single Cell Protein is studied. Technical process to produce Single Cell Protein by biologically degradation of wheat straw are proposed. The main conclusion are following points:1 .Effect of pretreatmental methods including milling process, dilute acid process, and ammonia process on the physical and chemical characteristics of wheat straw were studied. The reduction of crystallization degree and increase of effective surface adsorbing cellulase were studied by X-ray diffractometer, Scanner electron microscopy and Infrared spectra.2.The condition for cellulase production of five fungus is studied. Effect of culture medium’s composition and environmental factors on cellulase activity are explored. The experimental results show that five fungus can produce cellulase and degrade cellulose. The products of degradation contain glucose, xylose, disaccharide, and other saccharide.3.Cellulase is a kind of induce enzyme. The existence of glucose brings non-competitiveness inhibition. Cellulase produced by five fungus have better thermal stability and pH stability.4.Molds co-fermentation cannot raise protein content of wheat straw greatly. Mixed culture of mold and yeast can increase the protein content greatly because of the relationship of reciprocal symbiosis. The experiments show that yeast cannot only get rid of inhibition, but also affect positively the growth of fungus.5.Co-fermentation of Muti-fungus with wheat straw can increase the crud protein content by 261%, reaching to 21.51%. The content of protein is next only to yeast powder and bean, and is higher than wheat and corn. The protein contain 16 kinds of amino acids which is higher than the standard stipulated by Food and Agriculture Organization (FAO) of the United Nation, occupying 14.31% dry weight. The effect of the fungus chosen in the work is better than that of the stains exchanged with the oversea. 6.Co-fermentation of multi-fungus can increase the protein content and the valuein use of sugarcane dregs. This is very important for broadening feedstuff,raising feedstuff quality and developing the stockbreeding.更多还原