青方腐乳中益生乳酸杆菌的筛选鉴定及益生特性研究

Screening, identification and probiotic property of probioticLactobacillus in grey sufu

该研究从青方腐乳样品中分离具有潜在益生功效的乳酸杆菌,通过形态学观察及分子生物学技术对其进行鉴定。对筛选菌株进行人工胃液、胆盐的耐受性及其细胞表面特性测定,并对复筛菌株进行清除亚硝酸钠、降胆固醇、乳糖消耗、抑菌和抗氧化等益生特性试验。结果表明,从青方腐乳样品中共分离筛选得到24株菌(编号为S1~S24),通过人工胃液、胆盐的耐受性及其细胞表面特性测定复筛得到8株菌,分别为菌株S6、S10、S11、S13、S17、S21、S23、S24,其中菌株S6被鉴定为植物乳杆菌(Lactobacillus plantarum);其降亚硝酸钠、胆固醇及乳糖的能力分别为86.84%、61.22%、29.13%;羟基、DPPH自由基清除率、Fe2+螯合率分别为79.15%、56.29%、58.14%。综上,菌株S6对所有试验病原菌的拮抗能力最强,可作为潜在的益生菌。

In this study,Lactobacillus with potential probiotic property was isolated from grey sufu samples and identified by morphological observation and molecular biology techniques.The tolerance of artificial gastric juice and bile salt and the cell surface characteristics of the screened strains were measured,and the rescreened strains were subjected to probiotic property tests,such as scavenging sodium nitrite,lowering cholesterol,lactose consumption,bacteriostasis and antioxidation.The results showed that a total of 24 strains(numbered as S1-S24)were isolated and screened from grey sufu samples,and 8 strains were rescreened through measuring the tolerance of artificial gastric juice and bile salt,and their cell surface characteristics,which were strain S6,S10,S11,S13,S17,S21,S23 and S24,respectively.Among them,strain S6 was identified as Lactobacillus plantarum.Its ability to reduce sodium nitrite,cholesterol and lactose were 86.84%,61.22%and 29.13%,respectively.Hydroxyl radical,DPPH radical scavenging rate and Fe2+chelation rate were 79.15%,56.29%and 58.14%,respectively.In summary,strain S6 had the strongest antagonistic ability against all tested pathogens.Therefore,strain S6 could be used as potential probiotic.