青春双歧杆菌BA005抗逆性研究及其功能性应用

发布时间：2018-05-18 07:30

  本文选题：青春双歧杆菌 + 耐氧驯化　； 参考：《东北林业大学》2010年硕士论文

【摘要】： 本研究目的是从婴儿粪便中分离出青春双歧杆菌,经过生化及分子鉴定后,对此分离菌株进行抗逆环境驯化及筛选,对筛选出的优良菌株进行培养条件的优化,从而满足工业化生产的技术需求。为了确保其安全性,对该菌株进行毒理试验,同时进行功能性测试,并开发益生菌相关应用产品。 分离得到的疑似目的菌株,通过特征酶及发酵糖试验进行菌种属的筛选,再进一步应用分子生物学方法,提取菌株16S rDNA,通过基因序列的比对,对菌株进行种的鉴定。成功分离出目的菌株——青春双歧杆菌,通过发育树系统命名为：Bifidobacterium adolescentis BA005。 通过无氧-有氧交替驯化的方法,筛选出耐氧能力较强的青春双歧杆菌菌株,驯化后菌株的菌落形态和显微镜观察状态基本没有改变,菌体生长速度较无氧培养时缓慢,生长曲线中对数生长期拖后,但对培养后的活菌数影响不大,有氧培养24h后活菌数可达到3.30×1010 cfu/mL。 为降低工业生产中的生产成本,本研究采用玉米汁为培养基质,对耐氧Bifidobacterium adolescentis BA005进行培养条件响应面法优化。确定培养的最佳条件：接种量5%,玉米糖化液浓度12.1Bx,初始pH值6.48,培养温度37℃,发酵时间20h。在此条件下菌液最大OD值为1.819,活菌数为3.05×1012 cfu/mL。 人工模拟人胃、肠道酸性及酶环境,对耐氧Bifidobacterium adolescentis BA005进行抗胃肠道逆环境菌株筛选,并对常用抗生素耐性进行测试。结果表明,在模拟胃液环境中菌存活率为72.12%；在模拟肠道环境中菌存活率为53.33%；对大多数常用抗生素仅为中度敏感,对氨苄西林具有较强的耐药性。证明此菌株可以发挥其保健作用,维持人体健康。 对Bifidobacterium adolescentis BA005进行小鼠急性毒理试验及短期(30天)喂养试验,试验剂量超过了人可能食用剂量的10倍,试验小鼠没有出现中毒或死亡等异常状况,解剖其内脏主要器官,亦未见异常。从而证明此菌为安全菌株,可以放心食用并进行开发利用。 通过药物建造腹泻和便秘小鼠模型,对模型小鼠给予不同种类的益生菌剂,通过比较,Bifidobacterium adolescentis BA005菌株对腹泻和便秘症状的缓解和治疗功效最强。 基于青春双歧杆菌的诸多功能性,对其进行新产品开发。产品之一为格瓦斯发酵饮料,通过双歧杆菌和酵母菌的共同发酵,饮料中含有丰富的营养物质,酸甜适口；产品之二为功能性发酵饲料,通过双歧杆菌和酵母菌共同对常规饲料进行发酵,产生更利于动物吸收利用的营养物质。喂养奶牛可以提高其对常规饲料的消化吸收率,平衡胃肠道微生态系统,增强免疫力。
[Abstract]:The purpose of this study was to isolate Bifidobacterium pubertifolia from infant feces. After biochemical and molecular identification, the strains were acclimated and screened in the stress resistant environment, and the culture conditions of the excellent strains were optimized. In order to meet the technical needs of industrial production. In order to ensure its safety, toxicological tests, functional tests and probiotic application products were carried out. Strain 16s rDNA was extracted by molecular biology method, and the strain was identified by comparison of gene sequence. The strain was screened by characteristic enzyme and fermentation sugar test, and the strain 16s rDNA was extracted by molecular biology method. Bifidobacterium adolescentis BA005. The strain of Bifidobacterium youth with strong oxygen tolerance was screened by the method of anaerobic and aerobic alternate acclimation. After acclimation, the colony morphology and microscopic observation state of the acclimated strain were basically unchanged, and the growth rate of the strain was slower than that of the anaerobic culture. The logarithmic growth period in the growth curve was delayed, but it had little effect on the number of viable bacteria. After 24 hours of aerobic culture, the number of viable bacteria could reach 3.30 脳 1010 cfu-mL. In order to reduce the production cost in industrial production, the culture condition response surface method (RSM) was used to optimize the oxygen tolerant Bifidobacterium adolescentis BA005 culture by using corn juice as the culture substrate. The optimum culture conditions were determined as follows: inoculation amount 5, corn saccharification solution concentration 12.1Bx, initial pH 6.48, culture temperature 37 鈩，

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