摘    要开发新型安全的抑菌物质以替代传统的抗生素和杀菌剂已逐渐成为近年来研究热点，乳酸菌作为人类应用最早的一类益生菌再一次引起人们的关注。故本课题以筛选出具有抑菌活性的乳酸菌为出发点，用划线和涂布法分离菌株，利用牛津杯实验法筛选具有抑菌活性的乳酸菌，对筛选得到的乳酸菌进行16s-rDNA分子生物学鉴定；以常见的致病菌为指示菌，牛津杯实验法测定该菌株的抑菌图谱，并通过药敏试验研究菌株对抗生素的敏感性。89476

实验结果表明，此菌株对蜡样芽胞杆菌、金黄色葡萄球菌和铜绿假单胞菌等细菌和青霉菌有良好的抑菌作用，对氨苄西林、头孢唑啉、头孢噻吩等抗生素显示敏感性。本课题研究有望为提高此菌株的抑菌活性和开发新型抑菌产品提供参考。

Abstract In recent years, The development of new safe antibacterial substances to replace the traditional antibiotics and fungicides has gradually become a hot topic。 Lactobacillus as one of the earliest probiotics have attracted more and more attention。 In this paper, isolating the Lactobacillus with antibacterial activity was the starting point。 The strains were isolated by scribing and coating。 Oxford cup experiment was used to screen out Lactobacillus with antibacterial activity, and identified that Lactobacillus by 16s-rDNA molecular biology。 The antibacterial map of the strain was determined by Oxford Cup experiment with the common pathogens as the indicator bacteria, and the susceptibility of the strain to antibiotics was studied by drug sensitivity test。

The results showed that the strain had good antibacterial activity against fungi like penicillin and bacteria such as Bacillus cereus, Staphylococcus aureus and Pseudomonas aeruginosa, and was sensitive to antibiotics such as ampicillin, cefazolin and cefotaxime。 The aim of this study is to provide reference for improving the antibacterial activity of this strain and developing new antibacterial products。

毕业论文关键字：乳酸菌； 约氏乳杆菌； 抑菌谱； 抑制作用； 敏感性

Keyword：Lactobacillus; Lactobacillus johnsonii; Bacteriostatic spectrum; Inhibitory effect ; Sensitivity

目  录

1。 材料和方法 4

1。1。 实验材料和器材 4

1。1。1。 实验菌种 4

1。1。2。 药敏实验试纸 5

1。1。3。 仪器设备 6

1。1。4。 实验试剂 6

1。2。 培养基的配置 6

1。3。 乳酸菌的分离和筛选 9

1。3。1。 乳酸菌初分离 9

1。3。2。 对乳酸菌菌株的分离纯化 9

1。3。3。 筛选出有抑菌作用源Q于W优E尔A论S文R网wwW.yOueRw.com 原文+QQ75201,8766 的乳酸菌 9

1。4。 形态学观察 10

1。5。 菌种鉴定 10

1。5。1。 DNA模板制备