Study On The Liquid-state Unsterile Fermentation Process And Drying Of Pediococcus Acidilactici

The emergence of resistance to pathogenic, endogenous infections and double prestige dye has caused by long-term use of antibiotics in field of animal breeding European Union and other developed countries have already banned the adding of antibiotics in animal feed. Probiotics as a natural,green,no residue,non-toxic side effect of new type of feed additive has wide application prospect,which can promote animal growth,reduce animal disease,improve the quality of animal products and protect environment and other conditions.The article adopting the liquid fermentation with uncooked material technology,with Acidophilic micrococcus number of living bacterium as an indicator,studied the fermentation medium and fermentation conditions by using single-factor experiment.On the basis of single-factor experiment,the effects of the viable count for the culture medium and fermentation conditions were optimized by using the response surface method and orthogonal experiment method respectively,and the protective agent and dying process were preliminary.The result were as following;1.The liquid-state uncooked fermentation medium composition were studied by using single-factor experiment,and the influence of the viable count such as rice powder, soybean cake powder, MgSO4 7H2O, K2HPO4 were optimized according to the principle of Box-benhnken experimental design and quadratic regression equation model was established on the basis of single-factor experiment. The results proved to be highly reliable, which the model could explain 97.11% of the variation in the response value and Adj R-Squared is 0.9711, C.V is 0.51%,Adeq precision is 20.935.The results showed that the optimal fermentation medium composition were as follows:rice powder 4.8%, soybean cake powder 2.4%,MgSO4·7H2O 0.06%, K2HPO4 0.35%, sodium acetate 0.4%, CaCO3 0.4%, NaCl 3%, pH6.0. Through the verification experiment, the average viable count was 4.27×1010cfu/mL, which is close to the theoretical prediction value 4.57×1010cfu/mL. It showed that this model could reflect the experimental results.2.Effects of fermentation conditions on the viable count such as cultural tempera- ture,the initial pH value, inoculum,seed age and fermentation time were studied by using single-factor experiment,and the influence factors of the viable count were optimized by using orthogonal experiment.The results showed that the fermentation temperature was 37?,seed age was 36h,inoculum was 8%, fermentation time was 60h,the initial pH value was natural.Under these conditions,the viable count in fermentation broth reached 2.24×1011 cfu/mL?(3)The drying protective agent and drying process were studied preliminary with the survival rate as an index.The results showed that the appropriate protective agent of Pediococcus acidilactici were trehalose 14%, glycerol 8%, calcium carbonate 10%.The Suitable drying technology were drying temperature 45?, the fermentation broth pH 6.5, drying time 10 h.Under these conditions, the survival rate of Pediococcus acidilactici reached 39.03%.