【作者】 吴敬；

【导师】 贺银凤； 李少英；

【作者基本信息】 内蒙古农业大学 ， 农产品加工及贮藏工程， 2002， 硕士

【摘要】 本研究主要以内蒙古锡林郭勒盟地区牧民家庭采集的酸马奶酒为样品，进行了乳酸菌的分离及抗菌特性的研究。从10份酸马奶酒样品中分离出乳酸菌47株，经鉴定分别归属于乳杆菌属(Lactobacillus)、乳酸乳球菌乳酸亚种(L．lactis subsp．lactis)、粪肠球菌(E．faecalis)、坚强肠球菌(E．durans)、假鸟肠球菌(E．pseudoarium)、肠膜明串珠菌葡聚糖亚种(Lc．mesenteroides subsp．dextranicum)。分离的47株乳酸菌，排除酸、过氧化氢等干扰因素后，通过平板抑菌试验，筛选出了8株乳酸球菌、12株乳酸杆菌对指示菌利斯特氏菌(Listeria)有抑菌作用；其中，6株乳酸球菌离心后的上清液对指示菌利斯特氏菌(Listeria)有抑菌作用，其余12株杆菌和2株球菌的菌体对指示菌利斯特氏菌(Listeria)有抑菌作用。但所有47株乳酸菌均对大肠杆菌(E．coli)、金黄色葡萄球菌(Staphylococcus aureus)无抑菌作用。以4-3-2、3-3-2为试材，对其抑菌物质的产生条件及发酵粗提物进一步研究，发现这两株菌在对数末期抑菌活性最高，且在低pH条件(pH2.0)下对热相对稳定(121℃，30min)，4-2-2显示活性的pH范围为4.5～12，3-3-2显示活性的pH范围为4.5～8.5。除去菌体后的这两株菌的发酵上清液采用硫酸铵分级盐析和丙酮分级沉淀两种方法均可得到粗提的抑菌物。更多还原

【Abstract】 Forty-seven strains of lactic acid bacteria in this study were isolated from ten samples of koumiss collected from the heardsman’s home in Inner Mongolia-XiLinGuoLe region, and their antibacterial characterization were also studied. They respectively belonged to Lactobacittus L.lactis subsp.lactis E.faecalis, E.durans Rpseudoaviwn and Lc.mesenteroides subsp.dextranicum by identification. A total of forty-seven strains of lactic acid bacteria were screened for antagonistic activities under conditions that eliminated the effects of organic acids and hydrogen peroxide. Twelve strains of lactobacilli and eight strains of entercocci were only shown to inhibit the growth of indicator organism-Listeria through plate diseases test. Among them, the supernatants of fermented liquor from six of the eight strains of entercocci exhibited inhibitory activity against indicator organism-Listeria. And the bodies of twelve strains of lactocilli and two strains of entercocci also exhibited inhibitory activity against indicator organism-Listeria. But all the strains were not shown to inhibit the growth of indicator oigamsm-StaphylococcusaureuswdE.coli. Two of the six strains , 4-3-2 and 3-3-2, were chosen for further study. Maximum production of antibacterial substances were obtained in the late log period in MRS medium. The antibacterial substances were shown to be heat stable(12rC,30min)in acid conditions(pH2.0). Furthermore, the 4-3-2 strain was shown to be equally active at pH values ranging from 4.5 to 12, and the 3-3-2 strain was from 4.5 to 8.5. The antibacterial substances from cell-free culture liquor were extracted by the methods of amnonium sulfate salting-out or acetone precipitation.更多还原