摘要：  微生物发酵技术的广泛运用，使得饲料行业有了很大的突破，通过发酵，饲料中的蛋白质、淀粉、维生素等营养成分利用率提高，且改善了饲料的适口性，替代了抗生素的使用，使牲畜口粮的食用更加安全。本文对发酵饲料中菌种的选择进行了研究。经过16S-rDNA鉴定筛选出的菌种，优化了菌种的选择和培养条件，以发酵后发酵饲料的发酵液进行纤维素酶活性和蛋白酶活性的测定为评判，设计出最佳发酵的菌种选择和搭配。确定了最优条件：相比单菌发酵，组合菌发酵要更适合作为牲畜饲料中的菌种添加剂。其中（接种质量分数按酵母6%，芽孢杆菌1%，乳酸菌1%，黑曲霉1%），以黑曲霉+饲料中酵母+纳豆杆菌+乳酸菌的组合最优，更适用于作为饲料添加剂。通过纤维素酶活性和蛋白酶活性的测定证明利用微生物发酵的方法来使饲料提高其利用率和营养价值是可行的。71101

毕业论文关键词： 发酵饲料；单菌发酵；组合菌发酵；最优条件

Screening of the better microbial strain to ferment straw

Abstract：The extensive use of microbial fermentation technology makes the feed industry a great breakthrough,Through the fermentation, the utilization rate is improved about protein, starch, vitamins and other nutrients,.And improve the palatability of feed, instead of the use of antibiotics, so that the consumption of livestock rations more secure.In this paper, the selection of bacteria in fermented feed was studied. After 16S-rRNA identification, we select the better culture conditions of the strain. The optimum fermentation of the bacteria selection and match was determined by the determination of cellulase activity and protease activity in the fermentation broth of fermented feed. The optimum conditions were determined: the fermentation of the combined bacteria was more suitable as the additive in the livestock feed compared with the single bacteria fermentation, Among them (inoculation mass fraction by yeast 6%, Bacillus 1%, lactic acid bacteria about 1%, Aspergillus niger about 1%)，it is the best combination of Aspergillus niger + feed yeast + Bacillus subtilis + lactic acid bacteria, and is more suitable for use as feed additive.Through the determination of cellulase activity and protease activity, it is feasible to use microbial fermentation to improve feed utilization and nutrient value.

Key words: fermented straw；Single bacteria fermentation；Combine bacteria fermentation；Optimal condition 

目  录

1  绪论 3

1.1秸秆简介 3

1.2 发酵饲料简介 3

1.3  本文研究目的和研究内容 7

1.3.2  研究内容 7

2  材料和方法 8

2.1  试验材料 8

2.1.1  试验样品 8

2.1.2  试验试剂 8

2.1.3  仪器设备 9

2.2 筛选和发酵培养基的制备 9

2.2.1筛选培养基 9

2.2.2发酵培养基 9

2.3  试验方法 10

2.3.1  优势菌群的筛选（自然发酵饲料中优势菌群的筛选） 10

2.3.2菌株鉴定 11

2.3.3  发酵菌株的选择 11

2.3.4 还原糖测定——DNS法