The Development Of Yeast Liquid Medium For The Production And The Pre-test Of Yeast Antolysis Conditions Under Solid State Fermentation

In this study, eleven kinds of local agricultural products were used as fermentation substrate. The components of the medium were designed by Uniform Design. The yeast viable count in the liquid medium after fermentation and the content of yeast polysaccharide was determined to select the best carbon source and nitrogen source. And the composition of the liquid medium was determined by measuring the ratio of composite carbon source and composite nitrogen source and inorganic salts addition. The results show that:the composition of the liquid medium is0.90%anhydrous glucose,4.50%molasses,3.60%wheat bran,0.30%DDGS,0.28%cottonseed meal,0.08%yeast extract and0.08%(NH3)2SO4. Inorganic salts include0.30%KH2PO4,0.03%MgSO4and0.03%CaCl2.The viable cells’number is2.38X108cfu/mL. The content of β-glucan and mannan is651.60mg/L and210.80mg/L.The yeast was cultured in a liquid condition, then by increasing the temperature of fermentation to study the effect of yeast autolysis. The results show that:When the yeast was cultured for3h at50℃, the effect of yeast autolysis is the best. The content of β-glucan and mannan is14.58mg/L and2040.56mg/L. And the number of viable cells decreases to1.25×108cfu/mL.When Autolysis temperature is50℃, the fermentation time can be extended to study the effect of yeast autolysis under solid-state fermentation. The results show that:the suitable condition under solid-state fermentation for yeast autolysis is50℃and cultural time is3h. The content of β-glucan and mannan is260.89mg/g and403.15mg/g. And the number of viable cells decreases to0.59×108cfu/g.