摘要：大米发酵食品是指将大米在一定的温度下浸泡发酵一段时间，根据产品要求加工制成的不同品种的食品。而大米发酵液本身所携带的菌种在大米发酵食品的制作中显得尤为重要。本实验的目的是从大米自然发酵液中分离鉴定出优势菌株。通过实验发现大米发酵液中的优势菌种为乳酸菌，其次为酵母菌。乳酸菌通过形态学观察、生理生化试验及16S rDNA基因测序进行分离鉴定，其鉴定结果为乳酸乳球菌；酵母菌主要通过美蓝染色镜检，生理生化试验及26S rDNA D1/ D2 区序列进行鉴定，其鉴定结果为酿酒酵母。42090

毕业论文关键词： 大米发酵液；乳酸菌；酵母菌；分离鉴定

Isolation and extraction of dominant species in rice fermentation broth

Abstract: Rice is the main food crops in southern China. Rice fermented food is refers to rice under a certain temperature soaking fermentation a asked, according to the product request processing made of different varieties of food and rice itself carries the strains in the production of rice fermented food is particularly important. This experiment through the natural fermentation of rice, separated and identified the dominant strains in fermentation broth of rice. Through the experiment found that the dominant strains in fermentation broth of rice for lactic acid bacteria and yeast, lactic acid bacteria by using 9% hydrogen peroxide catalase test and Gram staining the morphological identification, and biochemical identification box identification, finally 1 6srDNA gene sequencing by lactic acid bacteria in rice as Lactococcus lactis; yeast by methylene blue staining and microscopic, physiological and biochemical tests were identified. Finally the 20rsDNA gene sequencing, the obtained yeast in fermentation broth of rice for Saccharomyces cerevisiae.

Key words: rice fermentation broth;lactic acid bacteria; isolation; identification

目录

1 引言 1

1.1 大米发酵食品的概况 1

1.2活性乳酸菌概况 1

1.3 酵母菌概况 2

1.4 细菌的鉴定常见方法 2

1.4.1 革兰氏染色法 2

1.4.2 菌落特征差异 3

1.4.3 生化特征测定 3

1.4.4 生理特征测定 3

1.5 国内外研究概况 3

1.6 本课题的研究目的和意义 4

2 实验材料和方法 6

2.1实验用试剂、培养基、设备、材料 6

2.1.1 实验试剂 6

2.1.2 培养基 7

2.1.3 实验用仪器设备 7

2.2 培养基及试剂的制备 7

2.2.1 大米发酵液的配置 7

2.2.2 培养基的配置 7

2.3 实验方法 8

2.3.1 对所筛选出的微生物进行计数 8

2.3.2 微生物的分离纯化 8

2.3.3 形态学鉴定 8

2.3.4 乳酸菌的鉴定 8

2.3.5 酵母菌的鉴定 9

3 结果与分析 10

3.1菌落记数