本文關(guān)鍵詞： 兩歧雙歧桿菌S17 粘附 拮抗 免疫反應(yīng) 發(fā)酵特性　出處：《西北農(nóng)林科技大學》2012年碩士論文　論文類型：學位論文

【摘要】：雙歧桿菌在腸黏膜上的粘附和定植被認為是選擇雙歧桿菌菌株的一項重要指標，直接關(guān)系到雙歧桿菌能否發(fā)揮其生態(tài)效應(yīng)。雙歧桿菌要定植在腸上皮細胞上，首先要進行粘附，如果只作為過路菌而不在腸道內(nèi)定植，就不能充分發(fā)揮雙歧桿菌的生理功能。雙歧桿菌在人類腸道中可以對多種腸道致病菌起到抑制作用，雙歧桿菌產(chǎn)生的胞外酶能降低致病菌或其毒素的特異性位點。雙歧桿菌在腸上皮細胞上定植后，會在腸道粘膜表面形成一層生物菌膜，抑制致病菌粘附到腸粘膜上，，還可以產(chǎn)生細菌素、抗生素、過氧化氫等物質(zhì)，刺激機體產(chǎn)生過氧化氫酶，抑制和殺滅革蘭氏陰性菌。本研究以Hela細胞系為模型，以長雙歧桿菌NCC2705作為對照，通過對兩歧雙歧桿菌S17對Hela細胞的粘附作用以及雙歧桿菌對幾種常見腸道致病菌的拮抗作用進行研究分析，對兩歧雙歧桿菌S17與嗜熱鏈球菌和德氏乳桿菌保加利亞亞種混合發(fā)酵凝固型酸奶工藝條件優(yōu)化，為研發(fā)雙歧桿菌微生態(tài)制劑提供理論依據(jù)和指導。主要研究結(jié)果： （1）兩歧雙歧桿菌S17和長雙歧桿菌NCC2705對Hela細胞均有較強的粘附能力，兩歧雙歧桿菌S17在Hela細胞上的粘附指數(shù)為19.42±5.43，長雙歧桿菌NCC2705的粘附指數(shù)為1.91±1.19，兩歧雙歧桿菌S17對Hela細胞的粘附能力強于長雙歧桿菌NCC2705。 （2）兩歧雙歧桿菌S17和長雙歧桿菌NCC2705對福氏志賀菌301、糞腸球菌V583、致病性大腸桿菌EPEC、沙門氏菌均有顯著的拮抗作用，兩歧雙歧桿菌S17對腸道致病菌的拮抗能力強于長雙歧桿菌NCC2705。 （3）兩歧雙歧桿菌S17和長雙歧桿菌NCC2705同四種腸道致病菌共同培養(yǎng)可降低細胞內(nèi)和分泌到上清液中TNF-α、IL-1β和IL-8含量，說明兩歧雙歧桿菌S17具有一定的抗炎能力，能夠刺激腸道免疫系統(tǒng)的作用，兩歧雙歧桿菌S17的抗炎能力強于長雙歧桿菌NCC2705。 （4）兩歧雙歧桿菌S17發(fā)酵乳的優(yōu)化工藝參數(shù)為發(fā)酵時間6h，接種量為10%，兩歧雙歧桿菌S17與混合發(fā)酵劑的比例為2:1，發(fā)酵溫度為42℃，發(fā)酵結(jié)束后，感官評分為97分，酸度為94.1oT。兩歧雙歧桿菌S17發(fā)酵乳酸度隨冷藏時間的延長而增大，活菌數(shù)隨冷藏時間的延長而減少，但其變化均在國家標準范圍之內(nèi)，不影響發(fā)酵乳的食用和銷售。
[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 鹵5.43, and that of NCC2705 was 1.91 鹵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- 偽, 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

本文編號：1497814