The Separation Of Polysaccharides Producing Strain And The Investigation Of Its Fermentation Conditions

Based on the excellent property,microbial polysaccharides are widely used in industrial production,possess strong competitive power in market and capacious developmental prosperity,so it is very significant to develop a new type of microbial polysaccharides.In this experiment a strain producing microbial polysaccharides was screened out,the medium composition and the fermentation conditions were investigated,physicochemical quality and rheological behavior were researched.Strains of producing microbial polysaccharides were isolated from soil,and the culture conditions for the original strain optimized were 3%manicol as carbon source,0.25%yeast extract as nitrogen source and it grows at an optimum temperature 23 ℃,an optimum capacity of 40 mL/250 mL and a pH of 7.0,inoculation of 8%.Research the physical and chemical properties of polysaccharides,the results show that:the polysaccharide is flat yellow powder,soluble in water and difficult in ethanol,butanol,chloroform and other organic solvents.The polysaccharide,pH = 7.39,with negative,does not contain sucrose,fructose,withnot reducing sugar,contains no starch,no uronic acid,no protein,without sulfate.By detecting the viscosity of the polysaccharides under different conditions,preliminary analysis of the polysaccharides rheological behavior,the results show that the polysaccharide reduced viscosity increases as increasing the concentration and decreases as increasing temperature.At pH = 8.0,the reduced viscosity is the largest;reduced viscosity decreases as increasing concentrations of cationic;CO32-,SO42-increases reduced viscosity,PO43-,Cl-decreases reduced viscosity,and mineral ions influence the reduced viscosity stability.