植物蛋白发酵乳酸菌对模拟胃肠道环境的耐受性研究

Tolerance of Lactic Acid Bacteria Strains for Phytoprotein Yoghurt Fermentation to Simulated Gastrointestinal Environments

通过模拟人体胃肠道环境,研究植物蛋白发酵乳酸菌植物乳杆菌FJAT-7926(Lactobacillus plantarum FJAT-7926)和干酪乳杆菌FJAT-7928(Lactobacillus casei FJAT-7928)在不同pH值人工胃液和不同胆盐浓度人工肠液下的存活情况。结果表明,pH3.0的人工胃液对2株菌的存活影响较小。经4h处理后,2株菌的存活数都在1×108cfu·mL-1以上,存活率分别为56.06%和55.65%。pH2.0的人工胃液对2株菌的影响较大,经2h处理后,2株菌的存活数降至1×105cfu·mL-1,4h后,2株菌存活数分别为3.67×102 cfu·mL-1和2.30×103cfu·mL-1。2株菌对不同胆盐浓度的人工肠液均有较好的耐受性。0.1%胆盐浓度的人工肠液对2株菌的存活基本没影响。随着胆盐浓度的升高,2株菌的存活率有所下降,但都与初始菌数维持在同一数量级上。在中高浓度胆盐(0.3%和0.5%)的人工肠液中处理4h后,植物乳杆菌FJAT-7926的存活率在70%以上,干酪乳杆菌FJAT-7928的存活率在40%以上。可见这2株菌均有较强的胃肠道环境耐受力,符合微生态制剂和乳酸菌发酵功能食品菌种耐受肠胃环境的要求,在植物乳酸菌发酵食品方面具有广阔的应用前景。

Previous studies have revealed that Lactobacillus plantarum FJAT-7926 and Lactobacillus casei FJAT- 7928 are promising fermentation agents for phytoprotein yoghurt beverage. The aim of our study was to examine the tolerance differences of the two strains under artificial gastric juice with different pH values and artificial intestinal juice containing different concentrates of bile salt and trypsin. The results showed that both of them have high tolerance responses to low pH value. When incubated in artificial gastric juice with pH3.0 for 4 h, survival of each tested strain was over 1X 108efu . mL 1 with a survival rate of 56. 06% and 55. 65 %, respectively. However, the survival of them declined to 1 X 105efu . mL 1 when incubated in the juice with pH2.0 for 2 h, and remained at concentrations of 3.67 X 10^6 cfu . mL-1 and 2.30 X 103 cfu . mL-1 in incubation for 4 h. Our results suggest that both of the tested strains have great tolerance to the artificial intestinal juiee. Though the survival rate of FJAT- 7928 and FJAT-7926 decreased as the concentration of bile salt increased, the concentrates of the both strains kept in the same order of magnitude. After 4 h incubation in the artifieial intestinal juice containing 0.3% or 0. 5% bile salt, the survival rates for FJAT-7926 and FJAT-7928 were more than 70% and 40%, respeetirely. The above indicated that both FJAT-7926 and FJAT-7928 have high tolerance to simulated gastrointestinal environments and both of them have broad prospects in the application of fermentation of phytoprotein yoghurt beverage.