Kinetic study of butanol production from various sugars by Clostridium acetobutylicum using a dynamic model

This paper presents a kinetic dynamic model of acetone–butanol–ethanol production by Clostridium acetobutylicum DSM 792 developed with the biochemical networks simulator COPASI. This model is an evolution of previous models described in the literature, updated by including various mono-, di-, hexose and pentose sugars: glucose, mannose, fructose, sucrose, lactose, xylose and arabinose. The kinetic relationships of uptake of substrate, butanol production, cell growth and cell death are also included. The batch fermentation tests were carried out at an initial sugar concentration ranging from 5 to 100 g/L. The data from the batch tests were used to assess the kinetic parameters of the model. This model gave satisfactory results for each sugar, both in terms of simulation of fermentation – the square correlation coefficient of metabolite concentrations, calculated by comparing experiments and simulations, ranged between 0.87 and 0.925 – and of comparison with the models reported in the literature. The effects of mono-, di-, hexose and pentose sugars on the growth and production of metabolites, including acids and solvents, were reviewed according to the proposed model. The low fermentation performance measured for xylose and lactose were interpreted taking into account the sugar uptake, the acid production and the hydrolysis path.