【作者】 林祥木；

【导师】 陈汉清；

【作者基本信息】 福建农林大学 ， 农产品加工与贮藏， 2004， 硕士

【摘要】 本文简述了纤维素和纤维素酶国内外研究的发展状况，并阐述了纤维素酶作用于纤维素的机理。本课题采用的出发菌株是绿色木霉13001，该菌株是公认的产纤维素酶活力较高的菌株。本文研究的目的是选育出一株产酶活力更高的菌株。 本课题相继对出发菌株绿色木霉13001采用紫外线诱变和⁶⁰Co-γ射线辐射，研究其诱变时间（诱变剂量）和正突变率的关系。通过测定滤纸崩溃进行初筛一些菌株，再对这些菌株采用液体摇床发酵实验，测定滤纸酶活力、CMC酶活力和β-葡萄糖苷酶活力三种酶活力，复筛后得到一株产酶活力更高的菌株1.0—28。该诱变菌株经测定比原出发菌株13001的滤纸酶活力、CMC酶活力和β-葡萄糖苷酶活力分别提高34.02％、31.13％和23.87％。 本文还对诱变菌株1.0—28的产酶活力的条件进行了初步探讨，得出一些相应的结论。发酵培养基的碳源以稻草粉最佳，加入麸皮有助于提高酶活力，其比例为稻草粉：麸皮为2：1为宜；氮源以无机氮源（NH₄）₂SO₄为佳；产纤维素酶最适培养基起始pH值为5.5；产酶活力的最适发酵温度为30℃；适宜的发酵时间是120—132h；接种量为2％—3％；本文还得出加入添加表面活性剂Tween80和种龄在16h—20h的菌株对产酶活力没有明显的影响。更多还原

【Abstract】 The dissertation discussed the development of cellulose and cellulase. It also introduced the principle that cellulase how to decompose cellulose. The strain Trichoderma virde 13001 was adopted in this research. Proverbially it is a good enzyme producing stain. The purpose of the present study was to attain a better one than parent stain by mutation.Based on the Trichoderma virde 13001,a mutated strain 1.0-28 was obtained through treatments of ultraviolet radiation and 60Co- ? radiation. After each treatment, the optimum time of ultraviolet radiation, the optimum dosage of 60’Co- ? radiation and the rate of positive mutation were researched. The strain isolation in each treatment was divided into two phases. First isolation was according to the test of filter paper collapse. Second isolation was according to the test of filter paper enzyme activity(FPase) . CMC-enzyme activity(CMCase) and 13 -glucosidase activity through liquid fermentation. The enzyme activity of the strain 1.0-28 was higher than parent stain. The result of higher were: FPase was 34.02%,CMCase was 31.13%, P -glucosidase was 23.87%The dissertation also studied the optimal conditions of enzyme production on the strain 1.0-28.The results showed that the better condition were: the carbon sources was straw powder, the ratio of straw powder and wheat bran equal 2:l,with (NH4)2SO4 as nitrogensources, cultural originally pH was 5.5,cultural temperature was 30 ?cultural time was 120-130h,the quantity of inoculability was 2-3%. The emulsifier Tween80 and the age of the strain had not obvious effect on the result.更多还原