Abstract: Production of xanthan gum by fed-batch fermentation was studied. Carbohydrate source hydrolyzed for 20 minutes can promote the production of xanthan gum, and the best DE value was 32.5%. The effect of initial sugar content, the component of feeding medium, the adding time and the way of feeding on production of xanthan gum was studied further by orthogonal experiments. The best initial sugar content and adding time and feeding way are 4%, 24h and exponential way respectively, and the feeding medium include 0.1% peptone is more adaptable. The final kinetics analysis reveals fed-batch fermentation is prior to batch fermentation.

Key words: xanthan gum, fed-batch, fermentation, kinetics