Safety Evaluation Of Lactic Acid Bacteria Isolated From Mare’s Milk And Its Products In Pastoral Areas Of Inner Mongolia

7strains of lactic acid bacteria belonging to Enterococcus spp. which were isolated from mare’s milk and its products (koumiss) in Xilin Gol, Inner Mongolia were investigated in the present study. The safety evaluation of the isolated strains were assessed in the test. The result of the resistance tests show that all of the7strains had the ability of salt tolerance, bile tolerance. thermal stability and resistance to pH4.0and pH9.6.The harmful metabolites of the isolated strains were evaluated in the test. The results of the indole test, nitrate reductase assay, the amino decarboxylase test and the hemolysis test were negative. Slight D-lactic acid were detected in the part of isolated strains. Through fermentation test,7strains had good properties of producing acid and solidifying milkThe results of the drug resistance tests indicated that all of the isolated strains were sensitive to erythromycin, amoxicilin and ampicillin. Strain JHZ15was intermediate resistance to norfloxacin, ofloxacin and ciprofloxacin. While strain JHZ17was only intermediate resistance to ciprofloxacin. The other strains were sensitive to quinolones.No drug resistance plasmids were detected in the7strains in the present study.In acute toxicity, we did not get the median lethal dose (LD50). The maximum tolerated dose (MTD) of acute toxicity were higher than1010CFU/(mL bw)20mL/(kg·d) which were belonging to non-toxic. In30days feeding test, no death were found in high dose group, middle dose group and low dose group. No significant differences (P>0.05) were found between the treatment groups and the control group in weight, food intake and the internal organ (heart, liver, spleen, lung and kidney) indices, except strain JHZ17with the high dose group which had significant difference with control group (P＜0.05) in weight increased. In addition, no bacterial translocation was observed.