乳酸菌发酵上清液对肠道致病菌抑菌特性的研究

发布时间：2018-03-07 23:30

本文选题：乳酸菌　切入点：上清液　出处：《中国农业科学院》2006年硕士论文　论文类型：学位论文

【摘要】： 乳酸菌，是一群可以发酵碳水化合物，并产生大量乳酸的革兰氏阳性杆菌或球菌的统称。乳酸菌的应用具有悠久的历史，人类远在古代，就不自觉地在食品酿造与加工上应用了乳酸菌。从乳酸菌被发现至今，对其研究已有一个多世纪的历史。人类通过百余年的研究和探索，已经对乳酸菌的来源、性质、功能、运用、培养等诸多方面，有了明确的了解和深入的探析。目前，国内外对乳酸菌的研究和探讨，一直将其拮抗作用作为研究的重点。随着人民健康意识的提高，人们越来越倾向于预防疾病而非治疗疾病，于是便对功能性食品产生了浓厚的兴趣，尤其是可作为食品的乳酸菌制品。所以，本文将选题的方向定于对乳酸菌的抑菌作用的研究，利用牛津杯法，通过17株乳酸菌(其中15株分离自酸马奶酒)发酵上清液对7株人源性肠道致病菌的抑菌实验(并对上清液调节不同pH值、经热和胃蛋白酶、胰蛋白酶处理)。初步分析乳酸菌抑菌活性物质的特性及抑菌能力范围，从而筛选出其中对人体肠道致病菌抑菌活性较强的菌株，以便作为发酵剂用于生产，，从而造福于人类。结果表明，这些乳酸菌上清液对肠道致病菌均有明显抑菌特性，在pH值2.0-3.0时抑菌活性最强，pH值达6.0以上丧失活性，并抑菌物对热稳定，其活性不被蛋白酶破坏，NaOH溶液对其活性有一定的减弱作用。
[Abstract]:Lactic acid bacteria are a group of gram-positive bacilli or cocci that can ferment carbohydrates and produce large amounts of lactic acid. The application of lactic acid bacteria has a long history. Unconsciously in food brewing and processing of the application of lactic acid bacteria. Since the discovery of lactic acid bacteria, it has been studied for more than a century. Through more than 100 years of research and exploration, human beings have studied the source, nature, function, application, cultivation and so on of lactic acid bacteria. At present, the antagonism of lactic acid bacteria has been regarded as the focal point of the research at home and abroad. With the improvement of people's health awareness, people tend to prevent diseases rather than treat diseases, so they have a strong interest in functional foods, especially as food products of lactic acid bacteria. Therefore, in this paper, the research on the bacteriostatic effect of lactic acid bacteria is focused on, and the Oxford Cup method is used to study the bacteriostatic effect of lactic acid bacteria. 17 strains of lactic acid bacteria (15 of which were isolated from yoghurt wine) were used to inhibit 7 strains of human intestinal pathogenic bacteria (and the supernatants were adjusted to different pH values by heat and pepsin). Trypsin was treated with trypsin. The characteristics and range of bacteriostatic activity of lactic acid bacteria were analyzed preliminarily, and the strains with strong bacteriostatic activity against human intestinal pathogenic bacteria were screened out so as to be used as starter for production and benefit human beings. The results showed that the supernatant of these lactic acid bacteria had obvious bacteriostasis characteristics against intestinal pathogenic bacteria, and the bacteriostatic activity of the supernatant of lactic acid bacteria was above 6.0 when pH value was 2.0-3.0, and the bacteriostasis was stable to heat. Its activity is not destroyed by protease. NaOH solution has a certain weakening effect on its activity.
【学位授予单位】：中国农业科学院
【学位级别】：硕士
【学位授予年份】：2006
【分类号】：R371

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