降解亚硝酸盐乳酸菌的分离及应用
时间:2019-04-27 10:57 来源:毕业论文 作者:毕业论文 点击:次
| 摘要: 本文分别用乳酸菌分离培养基从3中乳酸菌饮品中分离得到不同种乳酸菌，并在此基础上对各菌株在改良MRS固体培养基上进行进一步的分离纯化，得到生长能力较强的3株菌株，对其进行生理生化测试以及镜检，初步得出：d1,d2两株菌株为短乳杆菌，p1菌株为片球菌属。34921 将3中乳酸菌接种至改良MRS液体培养基中进行活化扩大，比较其降解亚硝酸盐的能力。并进行了不同条件对于3株菌株降解亚硝酸盐能力的影响实验（包括不同pH,不同温度，不同亚硝酸盐底物浓度以及不同接种量），对不同种乳酸菌降解亚硝酸盐的最适条件进行了初步的研究分析，以5%接种量为标准，在接种菌种后10小时测量亚硝酸盐含量，得出结果为：p1菌株降解亚硝酸盐最适pH值为4.5-6.2，最适底物浓度为400μg/ml,最适温度为37℃-40℃；d1菌株降解亚硝酸盐最适pH值为5.4-6.2，最适底物浓度为400μg/ml,最适温度为37℃；d2菌株降解亚硝酸盐最适pH值为5.4，最适底物浓度为400μg/ml,最适温度为37℃。 通过次实验可以说明，乳酸菌饮品中的乳酸菌可以明显起到降解亚硝酸盐的作用，且不同种乳酸菌降解亚硝酸盐的效力不同。 毕业论文关键词： 乳酸菌饮品;乳酸菌;降解;亚硝酸盐 The separation and application of nitrite lactic acid bacteria Abstract: In this paper, by lactic acid bacteria were isolated from culture medium from 3 beverage of lactic acid bacteria isolated from different species of lactic acid bacteria, and on this basis to various strains in modified solid culture medium for further separation and purification to obtain growth ability of the 3 strains, the physiological and biochemical tests and microscopy, come to the preliminary: d1, d2 strains Lactobacillus brevis, p1 strains for Pediococcus. The activation and expansion of the 3 lactic acid bacteria in the modified MRS liquid medium was carried out, and the ability of nitrite degradation was compared And the influence of different conditions on the experiment of 3 strains of nitrite degradation ability (including different pH, different temperature, different nitrite substrate concentration and different inoculation), the optimum conditions of different kinds of lactic acid bacteria to degrade nitrite are studied, with 5% inoculation amount as the standard, in 10 hours after inoculation measurement of nitrite content, the result is that p1 nitrite degradation and the optimal pH value was 4.5-6.2, the optimum substrate concentration is 400g/ml, the optimum temperature is 37℃-40℃; d1 nitrite degradation and the optimal pH value was 5.4-6.2, the optimum substrate concentration is 400 g/ml, the optimum temperature is 37℃; d2 degradation nitrite is the optimum pH value was 5.4, the optimum substrate concentration is 400g/ml, the optimum temperature is 37℃. Through the experiment, the lactic acid bacteria can obviously degrade the nitrite, and the effect of different nitrite is different. Keywords: Lactic acid bacteria beverage;Lactic acid bacteria;Degradation;Nitrite 目 录 1 绪论.1 1.1 本课题的国内外研究进展1 1.1.1 抗氧化剂去除亚硝酸盐.1 1.1.2 红曲色素降低亚硝酸盐.1 1.1.3 绿茶和茶多降解亚硝酸盐.1 1.1.4 亚硝基血红蛋白降低亚硝酸盐.2 1.1.5 酶法处理降解亚硝酸盐.2 1.1.6 生物降解亚硝酸盐.2 1.2 本课题的研究内容、目的及意义.3 1.3 亚硝酸盐中毒3 1.4 亚硝酸盐用途3 1.5 亚硝酸盐毒性4 1.5.1 毒性介绍.4 1.5.2 毒性危害.4 1.6 亚硝酸盐来源5 1.6.1 食物中作为发色剂和防腐剂的亚硝酸盐.5 1.6.2 从食物中添加的硝酸盐转化而来.5 (责任编辑：qin) |