Liquid-state fermentation with Bacillus subtilis Bs-07 to enhance anticoagulant function of Auricularia auricula polysaccharide

In order to improve the anticoagulant function of Auricularia auricula, Auricularia auricula polysaccharide （AAP） was converted into its derivatives by the microbial fermentation method and then polysaccharide derivatives with stronger anticoagulant activity were prepared. The optimal conditions for fermenting the polysaccharide from A. auricula were examined and the in vitro anticoagulant activities of transformed and untransformed polysaccharides were compared. Response surface tests and an orthogonal experiment indicated that the best conditions for microbial conversion of AAP3 were an AAP3 concentration of 4.0 mg/ mL, a ratio of substrate （AAP3 ） to donor （p-hydroxybenzoic acid） of 40：1, and a pH of 6.0. Bacillus subtilis Bs-07 was inoculated and then placed on a rotary shaker （ 120 r/min）, followed by fermentation for 48 h at 35 ℃. The conversion rate was found to be greater than 40%. The result of in vitro anticoagulant activity showed that the transformed polysaccharide improved activated partial thromboplastin time, prothrombin time, and thrombin time values and greatly enhanced anticoagulant activity compared to the untransformed polysaccharide.

Pressure shear assisted extraction of polysaccharide from Auricularia auricula and its biological activities

In this paper,using to the comprehensive scoring method,pressure shear assisted extraction was used to prepare polysaccharide from Auricularia auricula(PS-AAP)by orthogonal test to optimize the extraction.The highest comprehensive score(90.70)was obtained under 1:70 g/mL solid-liquid ratio,110°C reaction temperature,60 min reaction time and 1.0 MPa reaction pressure.Compared to AAP by water bath(WB-AAP),PS-AAP led to a higher extraction efficiency and decreased the relative molecular weight.In addition,infrared spectrum(FT-IR)analysis showed that pressure shear assisted did not change the polysaccharide structure.Scanning electron microscope(SEM)showed that PS-AAP was smaller and more broken by pressure shear assisted.Furthermore,the ratio of glucose to mannose in PS-AAP was relatively higher than WB-AAP,which also proved that PS-AAP had certain antioxidant and hypoglycemic activities.Compared with WB-AAP,the inhibitionα-glucosidase andα-amylase activity of PS-AAP increased by 11.37%and 24.43%respectively.These results revealed that PS-AAP has the poten-tial value of being a antioxidant and hypoglycemic agent.