副干酪乳杆菌诱导Caco-2细胞凋亡及其发酵乳贮藏品质的研究

以新疆马奶酒中自行分离得到的副干酪乳杆菌（Lactobacillus paracasei）M5L为对象，研究该菌株对结肠癌Caco-2细胞的抑制作用并分析发酵乳贮藏品质变化。结果表明，副干酪乳杆菌M5L可以在一定的盐浓度、胆盐浓度及酸性环境中较好的生长。当菌体以100∶1的感染系数作用于Caco-2细胞72 h后抑制率最佳；显微镜下观察活菌处理后的细胞发生明显的凋亡现象；流式细胞仪检测到副干酪乳杆菌M5L可以诱导Caco-2细胞内活性氧显著增加，并将细胞周期阻滞在合成期，且通过增大Caspase-3和Bax基因表达量，降低Bcl-2基因表达量来促进肿瘤细胞的凋亡。其发酵酸乳贮藏5 d时品质较佳，长时间的贮存会导致酸乳品质的劣变。

Caco-2 cell apoptosis induced by Lactobacillus paracasei and its fermented milk storage quality

Lactobacillus paracasei M5L was isolated from Xinjiang Kumiss, its inhibition effect on colorectal cancer Caco-2 cell was studied and the quality change of fermented milk was analyzed. Results showed that L. paracasei grew well at certain salt content, bile salt content and acid environment. The inhibition rate on Caco-2 cells was the optimal by L. paracasei treatment with infection factor 100∶1 for 72 h, the cells treated with L. paracasei showed obvious apoptosis phenomenon. Flow cytometry detection results showed that L. paracasei M5L could induce Caco-2 cells active oxygen content, arrest cell cycle in Synthesis phase, and the cancer cell apoptosis could be accelerated by increasing Caspase-3 and Bax gene express or decreasing Bcl-2 gene express. The quality of fermented milk was the optimal with storage time 5 d, and longtime storage can lead to yogurt deterioration.