目录
目录
摘要 1
关键词 2
Abstract IV
引言
引言 1
1 材料与方法 1
1.1材料 1
1.2样品采集 1
1.3菌落的纯化、分离 1
1.4菌种的形态学观察 1
1.3.1 菌种的形态学观察 1
1.3.2 菌种的分子生物学鉴定 2
1.5 菌株的鉴定 2
1.6 菌种产酸能力的鉴定 2
1.7 胆盐水解酶活性测定 2
1.8 统计分析 2
2 实验结果 2
2.1乳酸菌的分离和筛选 2
2.2乳酸菌菌种的鉴定 2
2.3乳酸菌的生长和产酸能力 3
2.4乳酸菌胆盐水解酶活性 4
3 讨论 4
3.1乳酸菌的主要生理功能 4
3.1.1产生抗菌物质抑制病原菌 5
3.2乳酸菌的分离和鉴定 5
3.2.1候选菌株的16Sr DNA测序结果 5
3.2.2乳酸菌的生长及产酸能力测定 6
3.3乳酸菌胆盐水解酶活性 6
3.3.1 胆盐水解酶的生理功能 7
3.3.2 胆盐水解酶的活性测定 7
4.1 小结 8
致谢 9
参考文献 10
优质樱桃谷肉鸭肠源乳酸菌的分离与鉴定
摘要
目前, 抗生素仍是防治畜禽细菌性疾病的常用药物, 然而在农业农村部全面禁抗的大背景下，越来越多科学研究支持益生菌作为促生长用抗生素的有效替代品。益生菌具有调节动物肠道微生物菌群、抵抗病原微生物入侵、促进动物生长发育及提高饲料利用率等作用，还可对肠道免疫失调引起的一系列慢性肠道病起到预防和治疗效果，是理想的抗生素替代品。益生菌需被服用后仍保持较高活性才能发挥有效作用，故需筛选出耐胃酸、胆盐后能达到活性位点的菌种。乳酸菌是一类能利用碳水化合物发酵产生乳酸的细菌的总称，它无芽孢、革兰氏染色为阳性，是微生态制剂中应用最早、最广泛的一类细菌；具有防治肠道感染、改 *51今日免费论文网|www.51jrft.com +Q: ￥351916072$ 
善肠道环境及提高畜禽饲料的利用率等重要作用。大量研究发现乳酸菌不但可通过胆盐水解酶来提高自身的胆盐胁迫抗性增加了其在肠道中的存活几率和稳定性，而且还能通过胆盐水解酶直接参与胆汁酸调控而实现其部分功能特性，因而乳酸菌胆盐水解酶是本实验研究的重点。
ISOLATION AND IDENTIFICATION OF HIGH QUALITY CHERRY VALLEY PORK DUCK INTESTINAL LACTOBACILLUS
ABSTRACT
At present, antibiotics are still commonly used in the prevention and treatment of bacterial diseases in livestock and poultry production. However, under the background of comprehensive bans by the Ministry of Agriculture and Rural Affairs, more and more scientific researches support probiotics as an effective alternative to growthpromoting antibiotics. Probiotics can regulate the intestinal microbial flora, defend against pathogen invasion, and improve the feed utilization rate and production performance of animals. They can also prevent and treat a series of chronic intestinal diseases caused by intestinal immune disorders. It is an ideal antibiotic substitute. Probiotics need to maintain a high activity after being taken to play an effective role, so it is necessary to screen out strains that can reach the active site after being resistant to gastric acid and bile salts. Lactic acid bacteria are the earliest, most widely used, and most diverse types of bacteria in microecological preparations. They are nonspore and Grampositive and can ferment carbohydrates and produce lactic acid; have enhanced immune function, improved intestinal environment and improved feed utilization of livestock. A large number of studies have found that lactic acid bacteria can not only improve their resistance to bile salt stress through bile salt hydrolase, increase their chance of survival and stability in the intestine, but also directly participate in the regulation of bile acid by bile salt hydrolase. Functional characteristics, so lactic acid bacteria bile salt hydrolase is the focus of this experimental study.

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