摘要
为了筛选出具有抑制致病性大肠杆菌作用的乳酸菌,本实验以大肠杆菌ATCC25922作为指示菌,抑菌实验采用牛津杯法。通过发酵上清液对大肠杆菌ATCC25922的抑菌实验,初步筛选出三株乳酸菌发酵上清液对大肠杆菌ATCC25922具有抑制作用,经过对16S rRNA基因进行系统发育分析,发现这三株乳杆菌均为嗜酸乳杆菌。随后又对这三株嗜酸乳杆菌进行了耐酸、耐胆盐及抗生素敏感性实验。结果表明:KLDS1.0901酸耐受性最强,而KLDS1.0902和KLDS1.1003与Lactobacillus acidophilus NCFM酸耐受性接近;对照菌株Lactobacillus acidophilus NCFM胆盐耐受能力最强,KLDS1.0901和KLDS1.1003与Lactobacillus acidophilus NCFM胆盐耐受能力差异不显著,KLDS1.0902胆盐耐受能力最弱;对于抗生素敏感性,三株嗜酸乳杆菌展现出类似的结果,对氨基糖苷类的抗生素展现出耐受;相比于KLDS1.0902,KLDS1.0901和KLDS1.1003有着更好的益生作用潜能,因此随后将对这两株菌在细胞和动物模型中对抗病原菌的作用进行进一步的研究。
In order to select lactic acid bacteria which have the ability to inhibit the growth of Escherichia coil, ATCC25922 was used as the indicator bacterium,the culture supernatant from lactic acid bacteria were used to determine if there were antimicrobial activities to the pathogenic Escherichia coil, using Oxford-cup tests.Three lactic acid bacteria were screened and all of these were determined as Lactobacillus acidophilus by phylogenetic analyses of 16S rRNA gene.Subsequently,the tolerance to gastric acidity and bile salts and antibiotic sensitivity of the Lactobacillus acidophilus were further evaluated.The results showed that KLDSI.090I had the best tolerance to gastric acidity, KLDS1.0902 and KLDS1.1003 had the closer tolerance ability to gastric acidity, compared Lactobacillus acidophilus NCFM.For the tolerance to bile salts, Lactobacillus acidophflus NCFM had the best bile tolerance ability and KLDSI.0902 had the weakest ability, there were no considerable differences among KLDSl.0901, KLDSI.1003 and Lactobacillus acidophilus NCFM for bile tolerance ability.All of strains showed similar results in the sensitivity to antibiotics, showing tolerance to aminoglycoside antibiotics.Therefore KLDS1.0901 and KLDS1.1003 had the better probiotic potential,compared KLDSI.OgO2.The antimicrobial effects of KLDSI.0901 and KLDS1.1003 against the pathogenic Escherichia Coil should be further studied in cellular and animal models.
出处
《食品工业科技》
CAS
CSCD
北大核心
2016年第13期152-156,共5页
Science and Technology of Food Industry
基金
国家863计划(2012AA022108)
