Study On The Cholesterol-reducing Characteristic Of Lactobacillus Isolated From Traditional Dairy Products In Pasture Region Of Inner Mongolia

In this study, some biological characteristics of 24 strains of Lactic acid bacteria isolated from dairy product were analyzed, such as tolerance to acid and bile salt, sensitivity to antibiotics, adhension to HT-29 cell and cholesterol removal in vitro and in vivo.16 strains of Lactobacillus plantarum showed resistance to bile salt in a certain degree among 24 strains of tested bacteria. All of them could grow in the medium contained 0.3 % sodium taurocholate and the survival rate was from 0.05% to 93.9%. When incubated at 37℃for 1h in the condition of pH 3.0, the survival rate of strains was between 5.9% and 103%. But compared with bile salt, the acid resistance was stronger.13 strains of tested bacteria had different sensitivity to diverse antibiotics. Most of them were sensitive to ampicillin, cefotaxime and clindamycin, but resistant to penicillin. All of them had sensitivity to piperacillin, amoxicillin, sulfomethorxazole, rifampin and nitrofurantoin, but resistance to vancomycin, ciprofloxacin and norfloxacin. Aimed at polymyxin B and ofloaxacin, the sensitivity was different among strains.The ability of adhension to HT-29 cell changed among 13 strains of tested bacteria. The rate of adhension to HT-29 cell was from 0.7 to 5.0.The screened bacteria differed in the rate of cheleterol-removel in vitro. The removal rate of chelesterol was from 28.5% to 43.1%. The further experiment indicated that each one could deconjugate bile salt. But the amount of dissociative cholalic acid was different from 0.65μmol/mL to 1.15μmol/mL.During the 20 day's animal experiment, the L.plantarum WH24-2-3 lowered the serum cholesterol of rats fedwith fat-enriched diet and prevented hyperlipemia from occuring. But L.plantarum WH15-3 had no effect on blood fat reduction.