Kinetics investigation of cell growth, xanthan production and sugar cane molasses consumption by Xanthomonas campestris

In this research, unstructured kinetic modeling for cell growth evaluation by X.campestris, xanthan production and sugar cane molasses consumption in a batch culture were investigated. Logistic model for biomass growth, Luedeking-Piret model for xanthan biopolymer production and modified Luedeking-Piret model for sugar cane molasses consumption provides an accurate prediction of the fermentation kinetics parameters with high coefficient of determination R 2 values. Luedeking-Piret model for xanthan biopolymer production in three different concentrations of sugar cane molasses (30, 60 and 90 g/L) as the sole carbon source substrate were studied. Good agreement between experimental and predicted values indicated that the unstructured models were able to describe this fermentation process successfully. The values of specific growth rate �� ������ of logestic model for sugar cane molasses (30, 60 and 90 g/L) were 0.029, 0.031 and 0.032 1/h respectively. The values of α and β are 5.280, 6.594, 8.518 and 0.072, 0.066, 0.086 respectively, which shows that the xanthan production is growth associated since the value of the growth associated parameter α is much more than the value of nongrowth associated parameter β in Luedeking Piret model. Moreover, the values of γ and �� in modified Luedeking-Piret model were obtained.