摘要：本实验中，我们对青藏高原土壤菌种进行了分离鉴定。通过观察菌株菌落形态结合细胞显微形态，鉴定了普鲁兰酵母（Aureobosidium pullulans）、酿酒酵母（Saccharomyces cerevisiae）及红酵母（Rhodotorula glutinis）等酵母菌，及里氏木霉（Trichoderma reesei）、黑曲霉（Aspergillus niger）及黄曲霉（Aspergillus flavus）等霉菌。而后从分离获得的菌株中初步筛选出10株与已知高产纤维素酶菌株较为相似的菌种，测定这10株菌株纤维素酶发酵液的滤纸酶活（FPA），发现10号菌株产纤维素酶活力较高，并判断该菌为里氏木霉，其FPA酶活高达7.2 U/ml，高于大多数菌种诱变或条件优化获得的纤维素酶活力。以上研究表明，青藏高原是优良的菌种资源库，该特殊地区环境中菌株的生理特性优于普通环境中菌株，因此青藏高原在菌种资源开发研究、再利用中具有重要价值。70580

毕业论文关键词：青藏高原土样，纤维素酶，菌种分离，滤纸酶活，菌株鉴定

Abstract: In this study, microbiology in the soil sample from Tibetan Plateau was separated and screened. Through observing the colonial morphology and the microstructure morphology of the cells, several strains were identified, which includes Aureobosidium pullulans, Saccharomyces cerevisiae, Rhodotorula glutinis, Trichoderma reesei, Aspergillus niger and Aspergillus flavus. According to the morphology colonies and cells, 10 strains which were similar to T. reesei, A. niger and A. pullulans, the strains with high cellulase, were selected for cellulose production. After determining the filter paper activity (FPA) of the fermentation broth with these strains respectively, No.10 strain was attained preliminary with the highest yield of cellulose among the 10 strains, and the FPA of No. 10 strain was as high as 7.2 U/ml, which was higher than most of the cellulose that had ever reported. These results showed that there were a large number of microorganisms in the soil of the Qinghai Tibet Plateau which could degrade cellulose. It is of great value to exploring the microbiology in Tibet Plateau and take full advantage of these natural resources.

Keywords: Soil sample from Qinghai-Tibet Plateau，Cellulase，Strain separation，Filter paper activity，Strain identification

目   录

1  前言 4

1.1  青藏高原土壤微生物研究的目的和意义 4

1.2  纤维素酶 4

2  材料与方法 6

2.1  土样 6

2.2  培养基与试剂 6

2.3  主要实验仪器 6

2.4  实验方法 6

3  结果与讨论 8

3.1  菌种分离及菌落形态鉴定 8

3.2  菌株细胞形态鉴定 9

3.3  产纤维素酶的菌株初筛 10

3.4  产纤维素酶的菌株复筛 10

结论 13

参 考 文 献 14

致  谢 16

1  前言

1.1  青藏高原土壤微生物研究的目的和意义

青藏高原被称为地球的“第三极”, 有“世界屋脊”之称，平均海拔4000m以上，高寒缺氧，降水少，太阳紫外辐射强，一直以其独具特色的自然景观和人文特色闻名于世界，是进行科学考察、研究和生态旅游的好地方，也是生态环境最独特、生物资源最富饶的自然资源宝库，具有极高的科研价值。其具有独特的自然地理条件，对气候变化较为敏感。青藏高原的土壤常年处于低温缺氧、寡营养、地磁辐射强等极端严酷的环境中，极端环境中通常会导致微生物的多样性及显著的特征性，生存于这一独特环境中的土壤细菌有其特殊的生理适应机制和特殊的代谢产物。因此，青藏高原微生物种类的分离及筛选就极其重要。论文网