Benjamas Cheirsilp

pp. 1059 - 1069

Abstract

Kinetics of kefiran production by Lactobacillus kefiranofaciens JCM6985 has been investigated. A mathematical model taking into account the mechanism of exopolysaccharides production has been developed. Experiments were carried out in batch mode in order to obtain kinetic model parameters that were further applied to simulate fed-batch processes. A simplification of parameter fitting was also introduced for complicated model. The fed-batch mode allows more flexibility in the control of the substrate concentration as well as product concentration in the culture medium. Based on the batch mathematical model, a fed-batch model was developed and simulations were done. Simulation study in fed-batch reactor resulted that substrate concentration should be controlled at 20 g L^-1 to soften the product inhibition and also to stimulate utilization of substrate and its hydrolysate. From simulation results of different feeding techniques, it was found that constant feeding at 0.01 L h^-1 was most practically effective feeding profile for exopolysaccharides production in fed-batch mode.