Milad Abdollahi - Dep. for Biotechnology, Faculty of New Sciences and Technologies, Semnan University, IRAN
Shakiba Darvishalipour - Dep. for Biotechnology, Faculty of New Sciences and Technologies, Semnan University, IRAN
Shamsozoha Abolmaali - Dep. for Biology, Faculty of Basic Science, Semnan University, IRAN

Consumption of probiotic microorganisms in the effective doses shows positive impacts on the health. In this study, resistance to papain and lysozyme and the effect of oral administration of ۴ probiotic isolates from dairy product were evaluated on mice. The tested-isolates were SUBC۲; Enterococcus faecium, SUBC۴; Lactobacillus plantarum, SUBC۵; Enterococcus faecalis, SUBC۵۷; Lactobacillus plantarum. To detect the resistance to papain, the isolates, were washed twice after overnight incubation, then treated in PBS with ۰.۳% papain for ۳h. The samples were plated by dilution method in MRS agar, incubated for ۱۸h at ۳۷ °C, and then the number of colonies compared to the control plates. Using the same method in lysozyme resistance test, the isolates suspended in PBS containing ۰.۵% lysozyme, and inoculated in medium MRS Agar. Every group of five female mice(۳۰-۳۵gr) was orally fed by gavage with ۱۰۸ CFU from fresh culture- washed with PBS buffer for ۱۴ days. PBS was used for five mice of control group. After removing diet for ۱۲h, blood sampling was performed and the sera collected. In the sera, changes in the liver enzymes were compared to controls. Finally, the immunization level was evaluated by indirect ELISA method. Sera of the BSA-immunized mice were used as the positive control. Isolates SUBC۲ and SUBC۵۷ showed the highest and the lowest survival rates as ۱۰.۶۵ and ۰.۴۱% respectively. Using the isolate SUBC۵۷ the highest resistance to lysozyme with ۹۱.۶۶% and in the isolate SUBC۴ the lowest resistance with ۶۵.۴۹% were detected. ۱۴ days orally administration of probiotic revealed no immunogenicity. The study of the alteration in the liver enzymes is under progression. These preliminary results indicated that dairy products show the potential to be used as probiotic for fermentation industry.

Enterococcus (sp), Immunogenicity, Lactobacillus (sp), Mice, Probiotic