两歧双歧杆菌S17的粘附和拮抗效应及发酵特性研究

发布时间：2018-02-09 11:22

  本文关键词： 两歧双歧杆菌S17 粘附 拮抗 免疫反应 发酵特性　出处：《西北农林科技大学》2012年硕士论文　论文类型：学位论文

【摘要】：双歧杆菌在肠黏膜上的粘附和定植被认为是选择双歧杆菌菌株的一项重要指标，直接关系到双歧杆菌能否发挥其生态效应。双歧杆菌要定植在肠上皮细胞上，首先要进行粘附，如果只作为过路菌而不在肠道内定植，就不能充分发挥双歧杆菌的生理功能。双歧杆菌在人类肠道中可以对多种肠道致病菌起到抑制作用，双歧杆菌产生的胞外酶能降低致病菌或其毒素的特异性位点。双歧杆菌在肠上皮细胞上定植后，会在肠道粘膜表面形成一层生物菌膜，抑制致病菌粘附到肠粘膜上，，还可以产生细菌素、抗生素、过氧化氢等物质，刺激机体产生过氧化氢酶，抑制和杀灭革兰氏阴性菌。本研究以Hela细胞系为模型，以长双歧杆菌NCC2705作为对照，通过对两歧双歧杆菌S17对Hela细胞的粘附作用以及双歧杆菌对几种常见肠道致病菌的拮抗作用进行研究分析，对两歧双歧杆菌S17与嗜热链球菌和德氏乳杆菌保加利亚亚种混合发酵凝固型酸奶工艺条件优化，为研发双歧杆菌微生态制剂提供理论依据和指导。主要研究结果： （1）两歧双歧杆菌S17和长双歧杆菌NCC2705对Hela细胞均有较强的粘附能力，两歧双歧杆菌S17在Hela细胞上的粘附指数为19.42±5.43，长双歧杆菌NCC2705的粘附指数为1.91±1.19，两歧双歧杆菌S17对Hela细胞的粘附能力强于长双歧杆菌NCC2705。 （2）两歧双歧杆菌S17和长双歧杆菌NCC2705对福氏志贺菌301、粪肠球菌V583、致病性大肠杆菌EPEC、沙门氏菌均有显著的拮抗作用，两歧双歧杆菌S17对肠道致病菌的拮抗能力强于长双歧杆菌NCC2705。 （3）两歧双歧杆菌S17和长双歧杆菌NCC2705同四种肠道致病菌共同培养可降低细胞内和分泌到上清液中TNF-α、IL-1β和IL-8含量，说明两歧双歧杆菌S17具有一定的抗炎能力，能够刺激肠道免疫系统的作用，两歧双歧杆菌S17的抗炎能力强于长双歧杆菌NCC2705。 （4）两歧双歧杆菌S17发酵乳的优化工艺参数为发酵时间6h，接种量为10%，两歧双歧杆菌S17与混合发酵剂的比例为2:1，发酵温度为42℃，发酵结束后，感官评分为97分，酸度为94.1oT。两歧双歧杆菌S17发酵乳酸度随冷藏时间的延长而增大，活菌数随冷藏时间的延长而减少，但其变化均在国家标准范围之内，不影响发酵乳的食用和销售。
[Abstract]:The adhesion and colonization of Bifidobacterium on intestinal mucosa is considered to be an important index of bifidobacterium selection, which is directly related to whether Bifidobacterium can exert its ecological effect. Bifidobacterium, which can inhibit many kinds of intestinal pathogens in human intestines, will not give full play to the physiological function of Bifidobacterium if it is only used as a passageway bacterium and not colonized in the intestines. The extracellular enzymes produced by Bifidobacterium can reduce the specific sites of pathogenic bacteria or their toxins. After colonization of intestinal epithelial cells, bifidobacterium forms a layer of biofilm on the surface of intestinal mucosa, which inhibits the adhesion of pathogenic bacteria to intestinal mucosa. It can also produce bacteriocin, antibiotics, hydrogen peroxide, stimulate the body to produce catalase, inhibit and kill Gram-negative bacteria. In this study, Hela cell line was used as model, and NCC2705 was used as control. The adhesion of Bifidobacterium bifidobacterium S17 to Hela cells and the antagonism of Bifidobacterium against several common intestinal pathogens were studied. To optimize the technological conditions of mixed fermentation solidified yoghurt with Bifidobacterium bifidobacterium S17, Streptococcus thermophilus and Lactobacillus de bulgaricus, and to provide theoretical basis and guidance for the development of bifidobacterium microecological preparation. 1) both Bifidobacterium bifidobacterium S17 and Bifidobacterium NCC2705 have strong adhesion to Hela cells. The adhesion index of Bifidobacterium bifidobacterium S17 on Hela cells was 19.42 卤5.43, and that of NCC2705 was 1.91 卤1.19.The adhesion of Bifidobacterium bifidobacterium S17 to Hela cells was stronger than that of NCC2705cells. (2) Bifidobacterium bifidobacterium S17 and Bifidobacterium NCC2705 had significant antagonistic effects on Shigella flexneri 301, Enterococcus faecalis V583, pathogenic Escherichia coli EPECand Salmonella. The antagonistic ability of Bifidobacterium bifidobacterium S17 against intestinal pathogenic bacteria was stronger than that of Bifidobacterium longus NCC2705. (3) Bifidobacterium bifidobacterium S17 and bifidobacterium NCC2705 co-cultured with four kinds of intestinal pathogenic bacteria could reduce the contents of TNF- 伪, IL-1 尾 and IL-8 in cells and secreted into the supernatant, indicating that Bifidobacterium bifidobacterium S17 had certain anti-inflammatory ability. Bifidobacterium bifidobacterium S17 has stronger anti-inflammatory ability than Bifidobacterium elongatum NCC2705. (4) the optimum technological parameters of bifidobacterium bifidobacterium S17 fermented milk were fermentation time 6 h, inoculation amount 10 h, the ratio of bifidobacterium S17 to mixed starter was 2: 1, fermentation temperature was 42 鈩

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