利用潜在益生菌粪肠球菌和长双歧杆菌分离株开发抗菌共生体。
Development of antimicrobial synbiotics using potentially-probiotic faecal isolates of Lactobacillus fermentum and Bifidobacterium longum.
机构信息
Department of Food Technology, Laboratory of Food Microbiology, A.T.E.I. of Thessaloniki, Thessaloniki, P.O. Box 141, GR-57400, Greece.
出版信息
Anaerobe. 2013 Apr;20:5-13. doi: 10.1016/j.anaerobe.2013.01.002. Epub 2013 Jan 24.
The aims of the present study were to investigate in vitro the antimicrobial activity of Lactobacillus fermentum and Bifidobacterium longum, isolated from faeces of healthy elderly individuals, against enterohaemorrhagic Escherichia coli (E. coli O157:H7) and enteropathogenic E. coli (E. coli O86), to determine the capability of the selected strains to tolerate acid and bile in vitro, to select suitable carbohydrates in order to enhance the growth and maximise antimicrobial activity of the putative probiotic organisms and examine the adhesion properties of the synbiotics. Antimicrobial activity of the putative probiotics and synbiotics was investigated by a microtitre method using cell-free culture supernatants (CFCS). Results of the antimicrobial assay showed that both putative probiotic strains produced compounds at pH 5 that lead to higher lag phases of both E. coli O157:H7 and E. coli O86. When half the quantity of cell-free culture supernatants of both probiotic strains was used at pH 5, B. longum maintained the same antimicrobial effect against both strains of E. coli, whereas L. fermentum lead to a higher lag phase of E. coli O86 only. Neutralization of the culture supernatants with alkali reduced the antimicrobial effect with only cell-free supernatant of L. fermentum causing lower maximum growth rates of E. coli O157:H7 and E. coli O86. L. fermentum appeared to be acid tolerant whereas B. longum was more susceptible to acid and both isolates were bile tolerant. A short chain fructooligosaccharide (scFOS) and an isomalto-oligosaccharide (IMO) proved to be the most effective substrates, enhancing antimicrobial activity for L. fermentum and B. longum respectively. The adhesion of the synbiotic combinations showed that L. fermentum, exhibited higher percentage of adhesion when grown on glucose and as a synbiotic combination with scFOS whereas B. longum exhibited lowest percentage of adhesion when grown on both glucose and IMO.
本研究的目的是研究从健康老年人粪便中分离出的乳酸杆菌和长双歧杆菌对产肠出血性大肠杆菌（E. coli O157:H7）和肠致病性大肠杆菌（E. coli O86）的体外抗菌活性，确定所选菌株在体外耐受酸和胆汁的能力，选择合适的碳水化合物以增强可能的益生菌的生长和最大限度地提高其抗菌活性，并研究共生体的粘附特性。采用无细胞培养上清液（CFCS）的微量滴定法研究了潜在益生菌和共生体的抗菌活性。抗菌测定结果表明，两种潜在的益生菌株在 pH 5 时产生的化合物导致 E. coli O157:H7 和 E. coli O86 的延迟期更长。当两种益生菌株的无细胞培养上清液的量减半时，在 pH 5 下，B. longum 对两种大肠杆菌菌株保持相同的抗菌作用，而 L. fermentum 仅导致 E. coli O86 的延迟期更长。用碱中和培养上清液会降低抗菌效果，只有 L. fermentum 的无细胞上清液才会导致 E. coli O157:H7 和 E. coli O86 的最大生长速率降低。L. fermentum 似乎耐酸，而 B. longum 对酸更敏感，两种分离株都耐受胆汁。短链果聚糖（scFOS）和异麦芽低聚糖（IMO）被证明是最有效的底物，分别增强了 L. fermentum 和 B. longum 的抗菌活性。共生体组合的粘附表明，L. fermentum 在葡萄糖上生长时显示出更高的粘附百分比，并且与 scFOS 作为共生体组合，而 B. longum 在葡萄糖和 IMO 上生长时显示出最低的粘附百分比。
Zotero 插件