【作者】 柳翰凌；

【导师】 周雨霞； 乌尼；

【作者基本信息】 内蒙古农业大学 ， 预防兽医学， 2006， 硕士

【摘要】 本研究对分离自内蒙古牧区乳及乳制品中的24株乳杆菌进行了酸耐受性、胆盐耐受性、药物敏感性、细胞黏附性等生物学特性的研究,并对经以上试验筛选所得菌株进行了体外和体内降胆固醇能力的测定。24株试验菌中,16株植物乳杆菌(Lactobacillus plantarum)显示出一定的胆盐耐受性,在含0.30%牛胆酸钠的MRS培养基中的生长率从0.05%～93.9%不等。在pH3.0环境中37℃培养1h后,存活率在5.9%～103%之间。对酸的耐受能力明显高于胆盐。经酸和胆盐耐受性试验筛选的13株受试菌,对抗菌药物表现出不同程度的敏感性。多数菌对氨苄西林、头孢噻肟和克林霉素敏感,对青霉素耐药;所有受试菌对哌拉西林、阿莫西林、复方新诺明、利福平和呋喃妥因敏感,对万古霉素、环丙沙星和诺氟沙星耐药;对多粘菌素B和氧氟沙星的敏感性因菌株而异。13株受试菌对HT-29细胞表现出不同程度的黏附能力,黏附率从0.7～5.0个菌/细胞不等。经筛选后的11株受试菌表现出不同的体外降胆固醇活性,胆固醇脱除率从28.5%～43.1%不等。在胆盐去结合试验中,各菌株对胆盐的解离程度不同,产生的游离胆酸量为0.65～1.15μmol/mL。体外筛得的2株植物乳杆菌中,L. plantarum WH24-2-3能显著抑制大鼠血脂的升高。而L. plantarum WH15-3在实验期内未表现出降低血脂的功效。更多还原

【Abstract】 In this study, some biological characteristics of 24 strains of Lactic acid bacteria isolated from dairy product were analyzed, such as tolerance to acid and bile salt, sensitivity to antibiotics, adhension to HT-29 cell and cholesterol removal in vitro and in vivo.16 strains of Lactobacillus plantarum showed resistance to bile salt in a certain degree among 24 strains of tested bacteria. All of them could grow in the medium contained 0.3 % sodium taurocholate and the survival rate was from 0.05% to 93.9%. When incubated at 37℃for 1h in the condition of pH 3.0, the survival rate of strains was between 5.9% and 103%. But compared with bile salt, the acid resistance was stronger.13 strains of tested bacteria had different sensitivity to diverse antibiotics. Most of them were sensitive to ampicillin, cefotaxime and clindamycin, but resistant to penicillin. All of them had sensitivity to piperacillin, amoxicillin, sulfomethorxazole, rifampin and nitrofurantoin, but resistance to vancomycin, ciprofloxacin and norfloxacin. Aimed at polymyxin B and ofloaxacin, the sensitivity was different among strains.The ability of adhension to HT-29 cell changed among 13 strains of tested bacteria. The rate of adhension to HT-29 cell was from 0.7 to 5.0.The screened bacteria differed in the rate of cheleterol-removel in vitro. The removal rate of chelesterol was from 28.5% to 43.1%. The further experiment indicated that each one could deconjugate bile salt. But the amount of dissociative cholalic acid was different from 0.65μmol/mL to 1.15μmol/mL.During the 20 day’s animal experiment, the L.plantarum WH24-2-3 lowered the serum cholesterol of rats fedwith fat-enriched diet and prevented hyperlipemia from occuring. But L.plantarum WH15-3 had no effect on blood fat reduction.更多还原