福菜乳杆菌CQ16Z1菌株的鉴定及益生特性的研究

Identification and Probiotic Characteristics of Lactobacillus futsaii Strain CO16Z1

目的系统鉴定菌株CQ16Z1并初步探讨其益生特性。方法采用16SrRNA测序、DNA-DNA杂交和生化特征鉴定方法等对菌株CQ16Z1进行系统分类鉴定。通过生长实验测定菌株CQ16Z1的耐酸、耐胆盐性。用荧光标记法,以人结肠癌细胞HT-29作为体外模型,研究菌株CQ16Z1的黏附性能。结果 16SrRNA测序表明,菌株CQ16Z1与福菜乳杆菌模式菌株(Lactobacillus futsaii JCM 17355T)最相似,相似性为99.87%;两菌株间的DNA-DNA杂交率高达91.9%;菌株CQ16Z1和模式菌株对49种碳源的利用仅有3个不同。菌株CQ16Z1可在pH 4.5的环境下生存,可耐受牛磺石胆酸钠、胆酸钠、禽胆盐、脱氧胆酸钠和牛磺鹅脱氧胆酸钠。菌株CQ16Z1对HT-29细胞的黏附率可达85.7%,高于大肠杆菌E57的黏附率。结论菌株CQ16Z1归属于福菜乳杆菌,且表现出耐酸、耐胆盐和肠道定植的益生特性。

Objective To identify the Lactobacillus futsaii （L. futsaii） strain CQ16Z1 and analyze its probiotic characteristics. Methods The methods of 16S rRNA gene sequencing, DNA-DNA hybridization and biochemical characters were used to identify the strain CQ16Z1. The growth experiment was adopted to detect the tolerance to acid and different bile salts. The fluorescence labeling method was used to investigate the adhesive properties by using the human colon cancer cell HT-29 as an in vitro model. Results The results of 16S rRNA gene sequencing showed that the strain CQ16Z1 was most similar to the strain L. futsaii JCM17355 T with a similarity value of 99.87 %. The DNA-DNA hybridization rate was 91.9 % between the strain CQ16Z1 and L. futsaii JCM17355 T. There were only 3 differences in the utilization of 49 carbon sources by the strain CQ16Z1 and the model strain. The strain CQ16Z1 could grow in the pH 4.5 environment and be resistant to taurolithocholic acid sodium, sodium cholate, poultry bile salt, sodium deoxycholate and taurocholate chenodeoxycholic acid sodium, respectively. The adhesion rate of the strain CQ16Z1 on HT-29 cells was 85.7 % and it was higher than that of Escherichia coli E57 . Conclusion The strain CQ16Z1 is classified as the species of L futsaii with the probiotic characteristics of acid tolerance, bile salt tolerance and intestinal colonization.