[Objective] The fermentation conditions of a mucopolysaccharide-producing bacterium LV-1 which isolated from soil sample were studied.[Method] The polysaccharide-producing bacterium was isolated by serial dilution method,the effects of carbon source,nitrogen source,the initial pH and temperature on producing polysaccharide by it were discussed to confirm the optimum fermentation conditions.[Result] The physicochemical properties showed that the polysaccharide was water-soluble,but insoluble in organic solvents including ethanol,butanol,and chloroform.It was neutral polysaccharide with negative charge and without reducing terminal.The pH of its solution was pH=7.5.There were no protein,fructose,uronic acid,sulphate and starch-like structure included in polysaccharide molecules.The optimum fermentation conditions for polysaccharide production were 3% mannitol as carbon source,0.25% yeast extract as nitrogen source,culture temperature 28 ℃ and pH=7.5.[Conclusion] The research could provide basis for development and utilization of LV-1 and industrialized production of mucopolysaccharide.
