Patent ID: 8097437

Claim:
A process for the production of polysialic acid having purity of greater than 99.0% and an average molecular weight of 70 KDa to 100 KDa, comprising the steps of: (a) preparing a nutrient medium containing sorbitol in an amount of 8 g/L to 12 g/L, yeast extract in an amount of 0.4 g/L to 0.6 g/L, casamino acids in an amount of 8 g/L, potassium hydrogen phosphate in an amount of 8 g/L to 12 g/L, copper sulphate in an amount of 0.001 g/L to 0.003 g/L, and magnesium sulphate in an amount of 0.4 g/L to 0.6 g/L; (b) inoculating a fermentor comprising the nutrient medium with a polysialic acid producing bacterium; (c) incubating the inoculated medium at a temperature of 30 to 40° C., a pH of 6.5 to 7.5, a dissolved oxygen percentage of 35 to 45% and an agitation of 100 to about 150 rpm; (d) harvesting the polysialic acid produced in step (c); and (e) concentrating or purifying the polysialic acid obtained in step (d).