| Soy whey wastewater is the main by-product from the soybean product,and the output is huge.Discharging it as sewage will pollute the environment and increase the cost of enterprises.The utilization of partial components in soybean whey will generate the pollutes again.So it is improtant for factory to wholly utilize soybean whey.This study mainly used soybean whey wastewater as fermentation substrate to produce probiotic supplements for feeding with functions of promoting digestion and inhibiting pathogens,and provided research ideas for the effective utilization of soybean whey wastewater.1.The probiotics supplements of digestive function were prepared with soybean whey wastewater.The strains were isolated from the fermented soy whey.The strains producing protease,amylase and cellulase were screened by clear circle method from the isolated strains and Bacillus subtilis.Bacillus subtilis A3 and Bacillus velezensis with higher enzyme activities were screened by quantitative determination of enzyme activity.Bacillus velezensis,may be alternative culture for probiotic supplements with digestive function.Bacillus subtilis A3 showed lower protease activities compared with that in medium producing enzymes.Response surface optimization was carried out to optimize the protease production capacity of Bacillus subtilis A3in soybean whey wastewater.The results showed that the initial p H was 7.2,the rotation speed was 184 r/min,the fermentation time was 36 h,and the protease activity was 191.25 U/m L,which was about 108 times higher than that before optimization.Probiotic supplements with Bacillus subtilis A3 had protease,amylase and cellulase,and the enzyme activities were respectively189.10±3.46 U/m L,332.80±7.75 U/m Land 45.70±2.21 U/m L.The probiotic supplements of digestive function could be stably stored.2.The probiotic supplements of antibacterial function were prepared with soybean whey wastewater.Four strains of antibacterial function were isolated from the fermented soy whey.The identification results showed that they were Lactobacillus plantarum M1-1,Lactobacillus plantarum M1-2,Lactobacillus fermentum M2-1 and Lactobacillus fermentum M2-2 according to morphology and 16Sr DNA genetic sequence.The four probiotics from soy whey,Lactobacillus acidophilus LA from pig intestines and Lactobacillus plantarum LP were tested probiotic functions.The six strains could inhibit pathogens by acid.Lactobacillus plantarum M1-1,Lactobacillus plantarum M1-2,Lactobacillus acidophilus LA and Lactobacillus plantarum LP could inhibit Escherichia coli,Salmonella typhimurium and Staphylococcus aureus by inhibitory adhesion.Lactobacillus acidophilus LA and Lactobacillus plantarum M1-1 showed stronger inhibitory ability for Escherichia coli and Salmonella typhimurium.The results were showed that these strains could go through gastrointestinal tract and colonized into intestines by the experiments on the tolerance to artificial gastric and intestinal fluid,hydrophobicity and self-aggregation ability,the adhesion to Caco-2 cells.These strains have anti-inflammatory effect and certain resistance to different kinds of antibiotics,and they can be considered as safe.Lactobacillus plantarum M1-1 and Lactobacillus acidophilus LA,with the stronger inhibitory ability for pathogens and adhesive ability to cells,were selected as culture to produce the probiotic supplements of antibacterial function.The probiotic supplements of lactobacillus 9×10~7 CFU/m L and 8.2×10~8 CFU/m L were p H 3.8.The probiotic supplements of antibacterial function can be stably stored.In this study,the alternative cultures for probiotic supplements were isolated.Two kinds of probiotic supplements could not only effectively utilize soybean whey wastewater,but also provided probiotics for livestock breeding industry.The study has application value for soybean industy. |
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