摘    要本研究旨在从不同样品中分离有抑菌活性的乳酸菌，然后鉴定菌种，研究该菌株的抑菌活性和安全性。结果表明：从小白鼠粪便中分离的乳酸菌对蜡样杆菌、大肠杆菌和金黄色葡萄球菌有抑制作用；菌种鉴定其为粪肠球菌；经抑菌活性测定，该菌株的代谢产物对细菌都有着不同程度的抑制作用，其中对乙型副伤寒沙门氏菌、金黄色葡萄球菌这两种细菌的抑制作用较大，而对真菌没有抑制作用；药敏实验结果显示该菌对氨苄西林、头孢噻肟、哌拉西啉、头孢呋辛等17种抗生素敏感，对头孢西叮、氧氟沙星、苯唑酉林、大观霉素等11种抗生素中度敏感，而对氨曲南、链霉素、妥布霉素等7种抗生素耐药，数据表明该菌株对选取的抗生素80 %敏感，而对其余20 %抗生素耐药，从比例上看出该粪肠球菌总体上安全程度高，耐药性低。89890

Abstract The aim of this study is to isolate the lactic acid bacteria with antibacterial activity from different samples, to identify the bacteria and to study the antibacterial activity and safety。 The results show: The lactic acid bacteria isolated from the feces of mice inhibited the growth of Bacillus cereus, Escherichia coli and Staphylococcus aureus; The strain was identified as Enterococcus faecalis; In the antibacterial activity test, the strain of metabolites of bacteria had different degrees of inhibition, which for hepatitis b paratyphoid salmonella, staphylococcus aureus, the two kinds of bacteria inhibition were bigger, but no inhibitory effect on fungi; Drug sensitive experiment results showed that the bacteria were sensitive to ampicillin, cefotaxime, cefazolin, cefuroxime and piperacillin West 17 antibiotics, moderately sensitive to cephalosporin Xi Ding, ofloxacin, oxacillin, spectinomycin and other 11 kinds of antibiotics, and not sensitive to aztreonam, streptomycin, tobramycin and other 7 kinds of antibiotics, the data shows that the strain was sensitive to the selected antibiotics 80 %, and was resistant to the other 20 % antibiotics, From the proportion, it is found that the Enterococcus faecalis has high safety and low drug resistance。

毕业论文关键词：粪肠球菌： 抑菌活性； 抗生素； 敏感； 耐药

Keyword: Enterorcoccus faecalis; bacteriostatic activity; Antibiotic; Sensitive; Resistant;

目    录

摘要1

Abstract1

1。材料与方法4

1。1材料与试剂4

1。1。1样品来源4

1。1。2实验仪器4

1。1。3试剂4

1。1。4培养基4

1。2实验方法4

1。2。1乳酸菌分离4

1。2。2抑菌活性测定4

1。2。2。1代谢产物的制备4

1。2。2。2指示菌平板的制备4

1。2。2。3抑菌源Q于W优E尔A论S文R网wwW.yOueRw.com 原文+QQ75201,8766 实验5

1。3乳酸菌鉴定5

1。3。1革兰氏染色5

1。3。2菌种鉴定5

1。3。2。1 DNA模板制备5

1。3。2。2 PCR扩增电泳5

1。3。2。3测序鉴定菌种5

1。4药敏试验5

1。4。1菌液制备5

1。4。2药敏实验5

2结果与讨论6

2。1形态学观察结果6

2。2菌种鉴定结果6

2。2。1电泳跑胶图6

2。2。2进化树构建图6

2。3抑菌活性测定结果7

2。4药敏实验结果8

3。结论9

参考文献10

乳酸菌（Lactic Acid Bacteria），革兰氏阳性细菌，其主要特点是能分解葡萄糖或乳糖等碳水化合物并产生大量乳酸。乳酸菌在代谢过程中会产生一些对食源性致病菌和腐败菌具有抑菌活性的物质如有机酸、过氧化氢和细菌素等[1]。其中乳酸菌细菌素是乳酸菌在代谢过程中通过核糖体合成机制产生的一类具有抑菌活性的多肽或前体多肽，其不仅能抑制与其亲缘关系相近的乳酸菌，而且对非乳酸菌的革兰氏阳性菌也有一定的抑制作用[2]。乳酸菌能抑制有害微生物生长的机制在食品和饲料等行业中得到广泛应用，比如在市场上双歧乳杆菌和粪链球菌就是一种食品防腐剂，因此对有抑制活性的乳酸菌进行研究不仅有着广阔的市场前景，而且也极具研究价值。来自优Y尔L论W文Q网wWw.YouERw.com 加QQ7520~18766