Fed-batch sorbitol to sorbose fermentation by A-suboxydans

Batch kinetics for sorbitol to sorbose bioconversion was studied at 20% sorbitol concentration. The culture featured 90% conversion of sorbitol to sorbose in 20 hours. Increasing the initial substrate concentration in the bioreactor decreased the culture specific growth rate. At 40% initial sorbitol concentration no culture growth was observed. The batch kinetics and substrate inhibition studies were used to develop the Mathematical Model of the system. The model parameters were identified using the original batch kinetic data (S-0 = 20%). The developed mathematical model was adopted to fed-batch cultivation with the exponential nutrient feeding. The fed-batch model was simulated and implemented experimentally. No substrate inhibition was observed in the fed-batch mode and it provided an overall productivity of 12.6 g/l-h. The fed-batch model suitably described the experimentally observed results. The model is ready for further optimization studies.