具有高效抑菌活性的肠道乳酸菌的筛选

Selection of high-efficiant antibacterial intestinal lactic acid becteria

目的:以从新疆和田维吾尔族长寿老人肠道中分离鉴定的18株实验菌和9株来自一般健康人肠道中的实验菌株作为研究对象,筛选具有高效抑菌作用的菌株,并确定起抑菌作用的可疑物质的性质。方法:采用滤纸片法筛选高抑菌活性的菌株,同时通过不同处理(温度、酸度、酶浓度)测定抑菌活性的变化,最后利用高效液相色谱法测定有机酸的含量并测定有机酸的抑菌能力。结果:从这27株中筛选出了三株具有广谱、高效抑菌作用乳酸菌,对这三株乳酸菌的抑菌成分进行了研究,最后发现起抑菌作用的物质是细菌素和短链有机酸。结论:27株实验菌株都有一定的抑菌能力,但从长寿老人粪便中分离出的所有菌株抑菌能力强于来自一般人肠道的所有菌株。乳酸菌代谢产物——有机酸(乳酸、丁酸和乙酸)和细菌素类(对热稳定且对酸和蛋白酶敏感)做主要底物进行抑菌实验。实验结果,在低pH条件下两类物质有明显的抑菌作用。

Objective： 19 strains of intestinal bacteria from the elderly and 8 strains from common health people as the experiment object,screening had hingh efficient antibacterial strain and determining the antibacterial effect of suspicious substance. Methods：Using filter paper method for screening high antibacterial activity strains, at the same time by different treatment （temperature, acidity, concentration of the enzyme） determination the changes of antibacterial activity,finally determination of the content of organic acid by using high performance liquid chromatography method and determination the inhibiting ability of organic acids. Results： From 27 strains breeding of a three strain with broad-spectrum,highly efficient inhibition effect of lactic acid bacteria,studing the bacteriostatic compositions were three strains of lactic acid bacteria,finally found the antibacterial effect of material were bacteriocins and short chain organic acid. Conclusion：27 bacterial strains had the ability of antibacterial ,but the ability of antibacterial of bacterial strains separated from dung of long- lived old people was stronger than the general people＇s. We conducted antibacterial test by using these metabolites of lactobacillus-organic acid （Lactic acid,butyric acid and acetic acid） and bacteriocins（stable to temperature and sensitive to protease） as main substrate. The result showed the two kinds of substances had significantly antibacterial effects at the low pH condition,which was essential condition to antibacterial activity.