本文選題：人源雙歧桿菌 + 酸致死篩選　； 參考：《上海交通大學(xué)》2012年碩士論文

【摘要】：雙歧桿菌是人和動物體內(nèi)十分重要的益生菌群之一,目前,雙歧桿菌的益生作用已經(jīng)得到普遍認(rèn)可,益生菌產(chǎn)品也得到了越來越廣泛的研究和應(yīng)用。益生菌制劑在服用過程中,需要保證一定劑量活的菌體最終進(jìn)入人體腸道,才能對宿主產(chǎn)生益生作用,而人源雙歧桿菌對胃部的低pH酸環(huán)境是高度敏感的。篩選出更加耐酸的人源雙歧桿菌對雙歧桿菌益生菌制品的生產(chǎn)應(yīng)用具有重要意義。目前,用于提高菌株耐酸性的主要方法是用亞致死酸性條件短時間處理而使菌株增強(qiáng)耐酸性,可是已有研究表明這一方法并不適用于雙歧桿菌。我們需要找出一種有效的方法來解決這一問題。 本實(shí)驗(yàn)采用了將雙歧桿菌長時間暴露在致死低pH環(huán)境下的酸致死篩選方法,用兩種不同的處理順序,從健康兒童的新鮮糞便中,篩選出了22株人源雙歧桿菌,并分別對其進(jìn)行了種屬的分子鑒定和耐酸性能的評價,選出了耐酸性能最優(yōu)的2株長雙歧桿菌SQS7-31與SQS4-64。通過對這兩株長雙歧桿菌連續(xù)20代的無壓力傳代后的耐酸性能評價,研究其耐酸性能的遺傳穩(wěn)定性,比較兩種不同的篩選處理順序?qū)δ退峋旰Y選結(jié)果的影響。研究結(jié)果表明這兩株長雙歧桿菌的耐酸性能可穩(wěn)定遺傳,直接對人體糞便通過酸致死處理來篩選雙歧桿菌和先在溫和條件下從糞便選出菌株再進(jìn)行酸致死處理和篩選,均可以獲得具有遺傳穩(wěn)定性的優(yōu)良耐酸菌株。這個研究結(jié)果也驗(yàn)證了對已有文獻(xiàn)相關(guān)論點(diǎn)的質(zhì)疑,說明并非只有直接對人體糞便進(jìn)行酸致死處理篩選才可獲得優(yōu)勢耐酸雙歧桿菌菌株。通過觀察兩株菌在不同膽汁鹽濃度下生長遲滯情況對其耐膽汁鹽性能進(jìn)行評價;通過觀察兩株菌對超氧陰離子的清除能力,對它們的抗氧化性能進(jìn)行評價;通過亞致死溫度的短時間處理,對這兩株耐酸菌株的耐熱性能進(jìn)行評價;通過計量菌體在模擬消化道中的幸存率,評價它們對人體不利環(huán)境的耐性。綜合所有的評價結(jié)果,最終選出長雙歧桿菌SQS7-31做為潛在的商業(yè)化生產(chǎn)菌株,該菌株已在中國微生物菌種保藏管理委員會普通微生物中心保藏并申請了發(fā)明專利。目前,耐酸性能優(yōu)良的長雙歧桿菌SQS7-31已經(jīng)被上海交大昂立股份有限公司做為生產(chǎn)備用菌株。
[Abstract]:Bifidobacterium is one of the important body of human and animal probiotics at present, probiotics Bifidobacterium has been widely recognized, probiotic products have also been studied and applied more and more widely. Taking probiotics in the process, need to ensure that a certain dose of living cells eventually enter the human gut, can produce probiotic effects on host pH, while the low acid environment of the stomach of human Bifidobacterium is highly sensitive. Screening is important to production application of bifidobacteria from more acid on Bifidobacterium probiotic products. At present, the main methods for improving strains resistant to acid is a short treatment with sublethal acidic conditions make enhanced acid resistant strains however, studies have shown that this method is not suitable for Bifidobacterium. We need to find an effective method to solve this problem.
This experiment used the Bifidobacterium long time exposed to lethal low pH environment acid lethal screening method, using two different processing order, from the fresh feces of healthy children, 22 strains were screened out from Bifidobacterium, and were evaluated for molecular identification and acid resistance of the genus choose the optimal acid resistance, 2 strains of Bifidobacterium longum SQS7-31 and SQS4-64. acid through performance evaluation without pressure after passage of the two strains of Bifidobacterium longum for 20 generations, the genetic stability of the acid resistance, compare two different screening treatment sequence of acid resistant strain screening results. The results of the study show that acid the performance of these two strains of Bifidobacterium longum genetic stability, directly to the human feces by acid lethal treatment screening of Bifidobacterium and under mild conditions were selected from waste acid treatment and screening of death Choose, can obtain excellent acid resistant strains with genetic stability. The results also verify the question of literature related argument, that it is not only directly on human waste acid treatment can be lethal screening aciduric Bifidobacterium strains. Through the observation of two strains of bacteria grown in different bile salt concentration hysteresis was evaluated the bile salts resistance performance; through the observation of two strains of superoxide anion scavenging ability, to evaluate their antioxidant properties; through the short time of sublethal temperature treatment, to evaluate these two strains of acid resistant strains by measuring heat resistance; bacteria in simulated digestive tract in the evaluation of their survival rate, the adverse environmental tolerance. All comprehensive evaluation results, and ultimately selected Bifidobacterium longum SQS7-31 strains as commercial production potential, the strain in Chinese. Physical culture preservation Management Committee General Microbiology center preservation and applied for a patent. At present, Bifidobacterium longum SQS7-31 excellent acid resistance has been Shanghai only Limited by Share Ltd as the production of spare strain.

【學(xué)位授予單位】：上海交通大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2012
【分類號】：R371

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前1條

1 蔡凱凱;以米糠為基質(zhì)納豆芽孢桿菌微生態(tài)制劑的研究[D];江西農(nóng)業(yè)大學(xué);2013年

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本文編號：1768167