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This study selenium-enriched comatus mycelium deep fermentation process, and evaluation of the effect of lowering blood sugar in their fermentation products. (1) through orthogonal experiment, from four comatus strains screened a higher biomass and strong selenium-enriched comatus strains Cc III, and to explore its resistance to selenium and selenium-enriched characteristics. The results show that, the Cc Ⅲ strain has resistance ability and strong selenium selenium-enriched solid culture maximum resistance to selenium concentration 10μg/mL, maximum resistance to selenium concentration of liquid culture 4μg/mL. The mycelial biomass 4.11 g / L, selenium-enriched rate of 50.57% in the selenium concentration 2μg/mL organic level of up to 92.95%. (2) study the impact of nutritional factors comatus mycelial growth and selenium-enriched screening to optimal medium formula for its comatus rich in selenium submerged fermentation: glucose 2%, 4% of the corn flour, peanut meal 0.4 %, KH 2 PO 4 0.2%, MgSO 4 · 7H 2 O 0.1%, VB1 10 × 10 -3 g / L, Na 2 SeO 3 4.4 × 10 -3 g / L, on this basis, on 5 d shake flask fermentation, The mycelium biomass as: 18.14 g / L selenium-enriched rate: 56.35%. (3) using the Plackett-Burman method, the method of combining the steepest ascent experiment and response surface experiment (Box-Behnken) comatus deep fermentation selenium-enriched culture conditions were optimized. The results showed that the fermentation conditions of seed age, medium volume, initial pH value is the main influencing factors. Optimized fermentation conditions: temperature 25 ℃, rotation speed 100 r / min, the liquid volume in 70 mL / 250 mL, seed age 133 h, 3% of the inoculum size, initial pH 5.8, fermentation cycle 5 d. Under these conditions, the mycelium biomass of 24.51 g / L, rich in selenium was 81.03%, 35.12% and 43.80% respectively compared with that before optimization. (4) the effects of selenium-enriched comatus mycelium and selenium polysaccharide on alloxan-induced diabetic mice hypoglycemic effect. Diabetic mouse model, the diabetic mice fed with 10% of the selenium-enriched comatus mycelium feed after 3 w, the the significant weight Recovery (p lt; 0.05); blood glucose concentrations were significantly lower (p lt; 0.05); serum and tissue MDA was significantly decreased (p lt; 0.05); SOD and GSH-Px activity was significantly increased in the serum and tissues (p lt; 0.05). Diabetic mice after intraperitoneal injection of 20 d comatus mycelium polysaccharide containing selenium (150 mg / kg bw, selenium content: 15.21μg / g), blood glucose concentration was significantly lower (p lt; 0.05); serum TC, TG and LDL were significantly reduced (p lt; 0.05), serum HDL was significantly increased (p lt; 0.05); liver and kidney tissue MDA decreased significantly (p lt; 0.05), antioxidant enzyme (SOD, GSH-Px and CAT) activity was significantly enhanced (p lt; 0.05), non-enzymatic antioxidants (GSH, VC and VE) concentrations were significantly increased (p lt; 0.05). Infer, selenium-enriched comatus mycelium and selenium polysaccharide significant hypoglycemic effect may increase the antioxidant capacity of diabetic mice.
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