4株乳酸菌对模拟胃肠环境的耐受性及生长特性研究

对4株来源于自然发酵肉制品中的乳酸菌进行耐酸耐胆盐性能的测定，选取在pH3.0和含0.3 g/100 mL胆盐的MRS培养基中存活率均超过50%的2株菌（M12、M23），进一步研究其在模拟胃肠液中的耐受性及MRS培养基中的生长特性。结果表明，这2株乳酸菌对人工模拟胃肠道环境有较好的耐受性，经过人工模拟胃液处理2 h后，存活率均＞50%，经人工模拟肠液处理10 h后仍可存活；这2株菌具有较强的增殖及产酸能力，24 h内均已进入稳定生长期，随着菌体数目的增加，培养基pH值快速降低，在肉制品的发酵温度范围内均能较好地生长。因此，这2株菌可作为潜在的益生菌菌株应用于肉制品的发酵。

Tolerance to simulated gastrointestinal environment and growth characteristics of four strains of lactic acid bacteria

The acid and bile tolerance of four lactic acid bacteria strains isolated from natural fermented meat products were determined. Two strains (M12 and M23) with high tolerance which showed more than 50% survival rate to MRS broth with pH 3.0 and 0.3 g/100 ml bile salt were further screened, to research their tolerance to simulated gastrointestinal environment and growth characteristics in the MRS broth. The results showed that both two isolated strains had high artificial gastrointestinal fluid tolerance which showed more than 50% survival rate after culture for 2 h in the artificial gastric fluid and they could survive after culture for 10 h in artificial intestinal fluid. Moreover, they had strong proliferation ability, acid production ability and they grew well within 24 h. With the increasing of bacteria number, the medium pH decreased rapidly, and they grew well within the fermentation temperature range of meat products. Therefore, these two strains can be used as potential probiotic strains for meat products fermentation.