Screening、Fermentation Properties And In Vivo Efficacy Of Cholesterol-Lowering Probiotic Lactobacillus Plantarum Strains

Screening、Fermentation properties and in vivo Efficacy of cholesterol-lowering ProbioticLactobacillus plantarum Strains is Supported by Department of agriculture modern agricultureindustry technology system construction of special funds of funded projects (No. cyrs-37).Overmuch cholesterol in the blood and diet has been recognized as a major risk factor forcoronary heart diseases and colon cancer, and many health conscious people are adoptingmeasures to decrease risk by reducing blood serum cholesteorl. A total of11Lactobacillusplantarum isolated from traditionally fermented food with cholesterol-reducing and probioticproperties were tested. One strain was selected as the optimal strain for all its tested abilities. Thefermentation characteristics and functional yoghurt of the strain was studied. The reduce serumcholesterol and antioxidant effects of selected strains of fermented milk were measured. Thesegives useful information for further exploitation and utilization of lactic acid bacteria intraditional fermented milk products．⑴Eleven L. plantarum strains isolated from the Northeast homemade sauerkraut and milktofo in Mongolia were screened for cholesterol-lowering functional by using σ-phthalaldehyde.By acid and bile tolerance and antimicrobial susceptibility testing, these strains were studied fortheir potentic probiotic.4strains (S2-5、S2-6、S4-1、C88)were screened for their excellentcholesterol-reducing ability and probiotic properties. Strain C88was selected as the optimalstrain for all its tested abilities.⑵More studies on the mechanism of cholesterol removal in vitro was carried out. Theresults showed that strains S2-5、S2-6、S4-1、C88were able to precipitate and assimilate cholesterols.⑶The fermentation properties of L. plantarum C88was assayed. The results showed that: L.plantarum C88displayed weak milk-coagulating activity, but strong proteolytic activity; L.plantarum C88maintained high viability in fermented milk during storage compared with L.rhamnosus GG. Added probiotics (inulin, glucose and fructooligosaccharides etc) can increasethe number of viable cells of L. plantarum C88.⑷Due to the functionality of L. plantarum C88, it will have a important meaning that isapplied to milk industry. Through the milk acidification, antagonistic activity and mix withcommercial yogurt culture YO-MIX was tested by yogurt experiment. The results showed that L.plantarum C88displayed low milk acidification and high survival ability, while no inhibitionwas observed towards the commercial yogurt starters used. Yogurt produced with L. plantarumC88exhibited no effect to the yogurt pH, titratable acidity, gel strength, water holding capacity.The strain not only increases the viscosity of yogurt but also promotes the sensory index ofyogurt.⑸T he effects ofL. plantarum C88、L. plantarum S4-1on serum lipids were estimated inICR mice fed cholesterol-enriched diets. The results showed that L. plantarum C88、L.plantarum S4-1feeding significantly lowered the serum total cholesterol, low-density lipoproteincholesterol and triglycerides level, meantime L. plantarum C88improved the content ofhigh-density lipoprotein cholesterol.⑹ICR subacute aged model mice, which were given subcutaneous injection of D-galactosecontinuously, were fed with fermented milk containing L. plantarum C88. The results showedthat L. plantarum C88fermented milk could significantly enhance the aged mice serum and livertissue SOD activity, liver tissue GSH-Px activity and liver tissue total antioxidant capacity(T-AOC), lowered the serum and liver tissue MDA content. It proved that the L.plantarum C88fermented milk has certain antioxidant effects on aged mice.