Optimization Of Culture Conditions And Efficacy Evaluation On Composite Probiotics Microecological Additive

Probiotics additive was made by probiotics and its metabolites, which canconditioning microflora imbalance, keep micro-ecological balance and improve healthstatus. Because micro ecological additive can complement the normal microflora inthe intestine from the number or species, it has the ability of adjustment ormaintenance of the intestinal microflora balance, enhance immune function, promotedigestion and absorption of nutrients. In the study, the optimization was made tochoose the best ratio of kefir and Bacillus, inoculum size, temperature and time as thebest culture condition. On the basis of the optimal culture conditions, mixed culturefermentation products were studied biological activity and immune activity. The mainresults are as follows:(1) In the study, the viable cell count was the evaluation index, by single factortest, components of high density medium, skim milk medium and soy protein mediumwere optimized. High-density medium: selection of whey and glucose as the carbonsource of high-density medium, Optimal ratio between the two is whey powder:Glucose=2:1; Selection of Whey protein concentrate(WPC) and Skim milk as theNitrogen source of high-density medium, Optimal ratio between the two is Wheyprotein concentrate: Skim milk=2:3. The final composition of high-density culturemedium ingredients is determined(g/L): Whey powder:54g, glucose:27g,concentrated whey protein powder20g, skim milk powder:30g, yeast7.63g,magnesium sulfate0.2g, manganese sulphate0.03g, calcium carbonate,6.20g. Skimmilk medium:10%(w/v) skim milk,3%(w/v) glucose; soy protein medium:10%(w/v) soy protein isolate,3%(w/v) oligofructose.(2) On the basis of the above studies, by single factor test and orthogonaloptimization experiments, the optimal culture conditions of mixed fermentation was determined: the ratio to kefir and bacillus was2:1, the inoculum size was4%, thetemperature was28℃and the time was20h. Under the culture conditions, the totalnumber of viable cells in the higher content of product, Lactic acid bacteria were3.14×1010, Yeast were6.80×109, Bacillus were2.78×1010, the total number of viablecells were6.60×1010.(3) The ability to reduce cholesterol of multiplex probiotics microecologicaladditive was evaluated, and extracellular polysaccharide of mixed fermentationproducts were determined.The results show that: In cholesterol degradationexperiments, three kinds of mixed system can be a certain degree of degradation ofcholesterol, high-density, skim milk and soy protein mixed system of cholesterolremoval rates were61.82%,58.11%and52.21%; three kinds of mixed systems areproduced extracellular polysaccharide(EPS), the EPS of soy protein mixed systemwas the maximum, reach to691.54mg/L, the mixed system of high-density systemsand skim milk produced EPS514.16mg/L and216.54mg/L respectively.(4) The antibacterial activity of multiplex probiotics microecological additivewas evaluated, and protease activity of mixed fermentation products were determined.The results show that: In inhibition experiments on bacteria, all three kinds of mixedsystem have a certain extent of Staphylococcus aureus, Escherichia coli andSalmonella typhimurium. Three kinds of mixed culture system can produce protease,high-density, skim milk and soy protein mixed system of protease activity were,205.54u/mL,125.35u/mL and146.24u/mL respectively.(5) The kefir grains and Bacillus mixed culture product was used to makeprobiotic powder, studied the immune activity of probiotic microflora compositeadditive. The results show that: complex probiotic microbe additive can improve theimmune organ index, can enhance the ability of spleen lymphocyte proliferation at thesame time, and phagocytic capacity of macrophages with a certain role in promoting,it can also enhance the cytotoxic activity of NK cells. In summary, probiotic microbeadditive compound has a certain immune activity, can enhance the body’s immunity toa certain extent.