Characterization of xanthan production under solid state fermentation on polyurethane foam

Time courses of biomass, glucose and xanthan during solid state fermentation with various initial glucose concentrations were determined and analysed with a metabolic flux method. The use of 80 g L-1 instead of 40 and 20 g L-1 glucose led to higher xanthan production. In the stationary phase of cells, the velocities (v) of all metabolic pathways are increased with increasing glucose concentration, while the highest specific rates (gamma) of glucose consumption and xanthan generation was obtained when the initial glucose concentration was 40 g L-1. Hence, under solid-state fermentation, an abundant initial carbon source is advantageous in improving the velocity of xanthan production, while moderately abundant carbon sources promote the conversion of carbon to xanthan.