高密度共生发酵和强黏附性优势菌株的筛选

Screening of dominant strains with strong adhesion for high-density symbiotic fermentation

目的 比较10株乳酸菌的活菌数,筛选高密度共生发酵和高黏附性的共培养菌株,为后期开发应用奠定基础。方法 对单个菌株及共培养菌株进行发酵活菌数的筛选,筛选出对Caco-2细胞黏附性强的优势菌株,并比较其耐酸、耐胆盐和抑制肠道致病菌能力。结果 10株益生菌菌株中,鼠李糖乳酪杆菌AI-11与发酵粘液乳杆菌AI-25、两歧双歧杆菌AI-91与动物双歧杆菌乳亚种AI-01的组合菌株较单个菌株具有协同效应,活菌数显著高于单个菌株(均t=8.878 0,P<0.001),且具有较好的抑制肠道致病菌大肠埃希菌和奇异变形杆菌的效果,较好的耐受pH 2.5的酸性环境和胆汁盐环境的特性,较鼠李糖乳酪杆菌GG和发酵粘液乳杆菌CECT 5716具有较好的Caco-2细胞黏附性(t=9.004 1, P<0.001;t=11.301 2,P<0.001)。结论 筛选出的2个共培养组合菌株在发酵能力和细胞黏附性方面具有活菌数高、黏附性强的优势,可应用于食品、功能食品及膳食补充剂中,以增强改善肠道菌群的功效性。

Objective To compare the viable counts of 10 lactic acid bacteria and screen co-culture strains with high density symbiotic fermentation and high adhesion,so as to lay the foundation for future development and application.Methods The viable counts of single strain and co-cultured strains were screened,and the dominant strain with strong adhesion to Caco-2 cells was further screened.The acid tolerance,bile salt tolerance and ability to inhibit intestinal pathogenic bacteria were compared among the strains.Results Among the 10 probiotic strains,the combined strains of Lacticaseibacillus rhamnosus AI-11 and Limosilactobacillus fermentum AI-25,and Bifidobacterium bifidum AI-91 and Bifidobacterium animalis subsp.lactis Al-01 had better synergistic effect than a single strain;their counts of viable bacteria were significantly higher than those of individual strains respectively(all t=8.8780,P<0.001),and they had a better inhibitory effect on intestinal bacteria Escherichia coli and Proteus mirabilis,a better tolerance to acidic environment and bile salt environment at pH 2.5,and a better Caco-2 cell adhesion than Lacticaseibacillus rhamnosus GG and Limosilactobacillus fermentans CECT 5716(t=9.0041,P<0.001;t=11.3012,P<0.001).Conclusion The two co-culture combination strains have the advantages of high viable counts and strong cell adhesion,which can be applied to foods,functional foods and dietary supplements to enhance the improvement of intestinal flora.