山羊乳饼中乳酸菌的分离鉴定及优良乳酸菌的初步筛选

Preliminary screening and isolation and identification of Lactic acid bacteria in goat dairy cake

采用传统分离培养法结合16S r RNA基因序列分析对样品中的乳酸菌进行分离鉴定,并通过模拟胃液、肠液和HT-29细胞粘附实验进行乳酸菌分离株筛选。6份样品中鉴定出46株乳酸菌,分为3个属,6个种,其中优势菌为屎肠球菌。在模拟胃液中菌株DLR1-1-4,DLR2-1-2,DLR3-2-4,DLR3-3-3,DLR4-7-4,DLR6-12-2在p H值为3.5的条件下存活率较高,活菌数≥107m L-1;菌株DLR3-2-4及DLR6-12-2在浓度为0.10%与0.15%的模拟小肠液中存活率较高,活菌数均≥107m L-1;通过与参考菌株LGG比较,菌株DLR3-2-4,,DLR4-7-4,DLR6-12-2的黏附率较高,黏附率分别达到16.33%,15.72%,18.16%,均高于LGG的黏附率。本研究为乳酸菌的开发利用提供科学参考。

In order to mining with excellent characteristics of probiotics, this research adopts the traditional culture method combined with the 16S rRNA gene sequence analysis of Lactic acid bacteria in the samples were isolated and identified, and the simulated gastric fluid and intes- tinal fluid and HT-29 cell adhesion experiments of Lactic acid bacteria isolated from screening, There are identified 46 strains of Lactic acid bacte- ria from 6 samples which divided into 3 generas. The dominant bacteria were Enterococcus faecium . In simulated gastric juice strains DLRI-I-4, DLR2-1-2, DLR3-2-4, DLR3-3-3, DLR4-7-4, DLR6-12-2 in pH 3.5 under the condition of high survival rate, living bacteria number is greater than or equal to 107cfu/mL.DLR3-2-4 and DLR6-12-2 strains of bacteria were more than 107cfu/mL live in the concentration of simulated intestinal fluid was 0.10% and 0.15%. Strain DLR3-2-4, , DLR4-7-4 , DLR6-12-2adhesion rate were much higher, which reached 16.33% 15.72% and 18.16% than those of LGG adhesion rate. In this study, 3 strains with good probiotic characteris- tics were obtained, and the probiotic characteristics of Lactic acid bacteria wotfld be studied further.