枯草芽孢杆菌的筛选和益生菌潜力评价

发布时间：2018-07-01 12:31

本文选题：枯草芽孢杆菌 + 耐酸试验　；参考：《山东农业大学》2015年硕士论文

【摘要】：抗生素被广泛应用于养殖业中,作为添加剂添加到动物饲料中,用以抑制肠道致病菌感染和促进动物生长。但是抗生素的使用会导致病原菌和非病原菌的耐药,而且这些耐药细菌可以在动物之间传播或进入环境中,污染环境和形成对人类的感染威胁,以及临床用药选药的困难。不容忽视的是,畜禽抗生素的添加使用,可能会导致抗生素性继发性感染的问题。专业人员和养殖者已经认识到抗生素的使用带来诸多的问题,在我国养殖业已经进入了后抗生素时代,微生态制剂是首选的替代物。微生态制剂因其兼具抑制致病菌和促进生长的双重功效,同时又绿色安全,不会造成细菌耐药,成为了良好的抗生素替代品,展现出远大的前景。本研究将多株不同来源的枯草芽孢杆菌进行横向比较,筛选出性能优秀的菌株。首先在动物体外从生长性能、耐酸试验、耐胆盐试验、抑菌试验、抗生素敏感试验和血凝试验等多个方面来比较它们的益生菌潜力,再将表现较好的菌株进行动物试验,检验其安全性以及作为假定益生菌的活性效果。结果显示,枯草芽孢杆菌B5株生长性能良好,在pH=3.0条件下存活率在90%以上,在pH=1.5时存活率仍然超过70%,且在0.3%的高浓度胆盐环境中1h后生存率超过60%。该菌对多株致病菌均表现出良好的抑制效果,对几种常见抗生素均没有表现耐药性。制成冻干粉制剂进行动物试验喂服家兔后提高了实验兔的生长性能,所以被认定为良好的益生菌株。本研究从多株枯草芽孢杆菌中成功筛选出一株表现优异的菌株,并进行了动物试验,为进一步研究将这株枯草芽孢杆菌推广应用到养兔业中打下了基础。
[Abstract]:Antibiotics are widely used as additives in animal feed to inhibit the infection of intestinal pathogens and promote the growth of animals. However, the use of antibiotics can lead to drug resistance of pathogens and non-pathogenic bacteria, and these drug-resistant bacteria can spread or enter the environment between animals, pollute the environment and form the threat of infection to human beings, as well as the difficulty of clinical drug selection. It can not be ignored that the addition of antibiotics in livestock and poultry may lead to the problem of antibiotic secondary infection. Professionals and breeders have realized that the use of antibiotics has brought a lot of problems. In our country, microecological agents are the first choice substitute in the post-antibiotic era. Because of its dual efficacy of inhibiting pathogenic bacteria and promoting growth, microecological agents can not cause bacterial drug resistance, so they have become a good substitute for antibiotics, showing a broad prospect. In this study, several strains of Bacillus subtilis from different sources were compared horizontally and the strains with excellent performance were screened out. First, the probiotic potential of animals was compared in vitro from growth performance, acid tolerance test, bile salt tolerance test, bacteriostatic test, antibiotic sensitivity test and hemagglutination test. Its safety and the activity of the hypothetical probiotics were tested. The results showed that the growth performance of Bacillus subtilis B5 strain was good, the survival rate of Bacillus subtilis strain B5 was more than 90% at pH 3.0, and still exceeded 70% at pH = 1.5, and the survival rate exceeded 60% after 1 hour in 0.3% high concentration of bile salt. The bacteria showed good inhibitory effect on many pathogenic bacteria, and showed no resistance to several common antibiotics. The freeze-dried powder was used in animal experiment to improve the growth performance of rabbits, so it was considered as a good probiotic strain. In this study, a strain of Bacillus subtilis (Bacillus subtilis) with excellent performance was successfully screened, and animal experiments were carried out, which laid a foundation for further study on the application of Bacillus subtilis to rabbit breeding.
【学位授予单位】：山东农业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：S816.3

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