Screening and Identification of Probiotic Lactobacillus Strains Inhibiting Intestinal Pathogens and Adhering to Caco-2 Cells

To screen Lactobacillus with intestinal probiotic characteristics and further develop probiotic resources,the probiotic characteristics of 15 Lactobacillus strains preserved in laboratory were screened and evaluated by Oxford cup,artificial gastrointestinal juice and adhesion to Caco-2 cells in vitro,using Lactobacillus rhamnosus as the control strain. The results showed that 15 Lactobacillus strains had certain inhibitory effect on both Salmonella strains,and the diameter of the inhibitory zone was 10.95~22.06 mm. Lactobacillus C174,D24,D599,C37 and D512 had good acid and bile salt tolerance,and the survival rate in artificial gastric juice was over 60% for 3 h and it was over 80% for 4 h in artificial intestinal juice. In the adhesion test,C174 had strong adhesion ability to Caco-2 cells. The number of adhesion was 740 CFU/100 cells,which was higher than that of control strain Lactobacillus rhamnosus GG(543 CFU/100 cells). The physiological and biochemical characteristics and 16S rRNA molecular sequencing identification of probiotic strain C174 with good adhesion capacity showed that the strain C174 was Lactobacillus plantarum,named Lactobacillus plantarum ZJ-174.Lactobacillus plantarum ZJ-174 was a potential probiotic with strong antimicrobial activity,acid and bile tolerance,and strong adhesion ability. It has application value in treating or preventing intestinal diseases of human and animals.