以胆固醇同化吸收能力为指标,用高效液相色谱法从12株乳酸菌中筛选出2株具有较高降胆固醇能力的乳酸菌YXB23和YDA12,胆固醇降解率分别为(35.33±4.51)%和(33.53±2.91)%。经过16S rDNA分子鉴定,YXB23属于植物乳杆菌,YDA12属于乳酸片球菌。通过体外耐酸性实验、耐胆盐实验和模拟胃肠道实验发现YXB23和YDA12在pH2.5胁迫8 h后的存活率分别为(99.42±0.30)%和(97.42±0.62)% ;在胆盐的质量分数为0.2%时胁迫8 h,YXB23和YDA12存活率分别为(77.51±0.46)%和(98.86±0.13)%,而胆盐的质量分数为0.3%时存活率分别为0%和(95.36±1.11)%;人工胃液消化3 h后,YXB23和YDA12的存活率分别为(85.46±1.76)%和(85.41±1.47)%,将消化液转接入人工小肠液消化8 h后,植物乳杆菌YXB23与乳酸片球菌YDA12的存活率分别为(90.47±2.94)%和(88.95±2.29)%。比较2株乳酸菌,筛选出YDA12为具有良好胃肠道耐性的潜在降胆固醇乳酸菌。
Two strains of lactic acid bacteria, YXB23 and YDA12 with high cholesterol-lowering ability were screened from 12 lactic acid bacteria using high performance liquid chromatography (HPLC), the cholesterol assimilation rates were (35.33±4.51)% and (33.53±2.91)%, respectively.16S rDNA analysis suggested that YXB23 belonged to Lactobacillus plantarum and YDA12 belonged to Pediococcus acidilactici strain.YXB23 and YDA12 were incubated in MRS at pH2.5.After 8 h, the survival rates of YXB23 and YDA12 were (99.42±0.30)% and (97.42±0.62)%, respectively.After incubation with 0.2% bile salt in MRS for 8h, the survival rates of these two strains were (77.51±0.46)% and (98.86±0.13)%.When the content of bile salt was increased to 0.3%, the survival rates of YXB23 and YDA12 were 0% and (95.36±1.11)%, respectively.After incubation in artificial gastric juice for 3 h, the survival rates of YXB23 and YDA12 were (85.46±1.76)% and (85.41±1.47)%.When they were transferred to artificial intestinal juice (2%,v/v) and incubated for 8h, the survival rates of YXB23 and YDA12 were (90.47±2.94)% and (88.95±2.29)%.After comparison of thses two strains, YDA12 was select as the potential Cholesterol-lowing lactic acid bacteria due to it′s better bile salt resistance.