Research On The Microbial Fermentation Of Weat Bran Polysaccharide And The Antioxidant Activity Of Crude Polysaccharide

The purpose of this study is to prepare weat bran polysaccharide by microorganism conversion in the weat bran together with the accessories such as soybean meal and corn meal,and to study on bioactivity of crude polysaccharide.This thesis focused on the following five aspects:1 Microbial fermentation and preparation of Wheat Bran Polysaccharides1.1 Determination of fermentation strains and combinationsBy using the content of weat bran polysaccharide in the products as the index,L.plantarum P8,Yeast(CGMCC2.119),Bacillus subtilis(CGMCC1.0892),Bacillus licheniformis(D3)were used as spawn to produce weat bran polysaccharide with single fermentation and mixed fermentation.The result showed that the best mixed fermentation multi-strains were Yeast(CGMCC2.119)and Bacillus subtilis(CGMCC1.0892),while the content of weat bran polysaccharide in the product could reach 44.55mg/g.1.2 Determination of the multi-strains inoculums size ratio and accessoriesDetermination of the strain ratio and accessories by Plackett-Burman test and response surface methodology,we found that the content of weat bran polysaccharide could reach 55.92mg/g when the best multi-strains inoculums size ratio was Yeast(CGMCC2.119)and Bacillus subtilis(CGMCC1.0892)6.7:3.3 and solid culture medium was composed of 80.46%weat bran meal,9.32%soybean meal and 10.22%corn meal.1.3 Determination of synergistDetermination of synergist from 10 organic and inorganic salts including MgSO4,MnSO4,CaCl2,KH2PO4,Urea,Sodium citrate,Potassium sodium tartrate,HA-Na by Plackett-Burman test.we found that the significant factor is urea to the content of weat bran polysaccharide(P<0.05).As the synergist,the additive amount of urea was 0.1%,while the content of weat bran polysaccharide in the product could reach 122.8mg/g.1.4 Determination of fermentation conditionsOptimizing fermentation conditions by single factor test and response surface methodology,the results showed that when fermentation temperature was 35.4?,fermentation time was 52.7h,total inoculation amount was 10.4%and the ratio of material to water was 1:1.16,the weat bran polysaccharide in the product could reach 130.21mg/g,increased by 6%before optimization1.5 Determination of extraction conditionsOptimizing extracting conditions by single factor test,the results showed that the best extracting process condition was temperature 80?,the ratio of material to water was 1:20 and time 30min.2 Study on antioxidant activity of crude polysaccharides of wheat branStudy the crude polysaccharides of wheat bran on oxidative stress in wistar rats by establishing animal models of oxidative stress induced with diquat.Thirty-six male Wistar rats were divided into six groups.CL,CM and CH:orally treated with crude polysaccharides at doses of 100,200 and 400 mg/kg BW,respectively;CT:orally treated with saline,normal control;NC:orally treated with saline,negative control;and PC:orally treated with vitamin C at 100 mg/kg BW,positive control.On d 14,NC,CL,CM,CH and PC groups received 0.1 mmol/kg BW of diquat intraperitoneally,whereas,CT group received an equal dose of saline.The rats were alaughtered after 24h.The blood,liver,kidney,nouns and spleen were collected to measure the antioxidant indices and pro-inflammatory cytokine levels.The results showed that crude polysaccharides of wheat bran could increase the activities of CAT,SOD and GSH-Px enzyme activity and level of GSH belonging to non enzymatic system and reduce the levels of MDA belonging to lipid peroxidation and levels of inflammatory factors such as TNF-a,IL-6,IL-2 and IL-1?compared to the NC group in the plasma,liver,kidney,nouns,and spleen.In conclusion,crude polysaccharides of wheat bran effectively alleviated the oxidative stress by diquat in Wistar rat.The protective effect of crude polysaccharides of wheat bran was in a dose dependent manner.