【摘要】 为筛选具有潜在益生特性的乳酸菌,对从晋西北自然发酵谷物食品—酸粥发酵液中分离的20株乳酸菌进行了体外耐酸、耐胆盐、疏水性、降胆固醇和抗氧化性研究;对筛选到的益生菌进行了抗生素耐药性测定。结果表明,14株菌在pH值3. 0的培养基中2. 5 h后的存活率大于50%; M-1、M-5、M-8、M-9、M-10和M-13对胆盐的耐受性较强; M-19的疏水性最强;有12株菌对胆固醇的降解率大于50%; M-8的抗氧化能力较强。总之,M-1、M-5、M-8、M-10和M-15具有潜在益生特性,结合前期形态观察、生理生化特征和16S r DNA分析将它们鉴定为短乳杆菌(Lactobacillus brevis)。这5株短乳杆菌对抗生素的耐药性不同,对青霉素、头孢噻肟、四环素和链霉素耐药,对氨苄西林、红霉素和氯霉素敏感。更多还原

【Abstract】 In order to screen potentially probiotic lactic acid bacteria,20 strains were isolated from the fermentation broth of a naturally fermented cereal food,sour porridge,from northwestern Shanxi. Their tolerances to acid and bile salt,hydrophobicity,cholesterol-reducing ability,and antioxidant activity were in vitro investigated. The probiotics selected were then examined for their resistances against antibiotics. The results showed that the survival rates of14 strains after growing in a medium with pH3. 0 for 2. 5 h were more than 50%. Strains M-1,M-5,M-8,M-9,M-10 and M-13 had stronger tolerance to the bile salt. Strain M-19 exhibited the highest hydrophobicity. The cholesterol degradation rates of 12 strains were more than 50%. Strain M-8 had a powerful antioxidant activity. In conclusion,strains M-1,M-5,M-8,M-10 and M-15 had potentially probiotic characteristics with different antibiotic( penicillin,cefotaxime,tetracycline and streptomycin) resistances and sensitive to ampicillin,erythromycin and chloramphenicol.They were identified as Lactobacillus brevis by morphology observation,physiological and biochemical characteristics and 16 S r DNA analysis.更多还原