Production of polysialic acid from fed-batch fermentation with pH control

During batch fermentation pH affects the production of biomass and polysialic acid in Escherichia coli K235-WXJ4. When the pH of the medium was maintained at 6.4 during the stationary phase, polysialic acid production was prolonged and the specific rate of polysialic acid biosynthesis was higher than when the fermentation process was not controlled for pH. Controlling the pH during fed-batch fermentation of polysialic acid increased the yield of dry cell weight and polysialic acid, which reached 10.16 and 2606 g/l, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.