Abstract:
Thie current study focused on using a previously published model known to accurately predict the cultivation
of Actinobacillus succionogenes on glucose in a NaOH neutralised system, for the prediction of batch system
behaviour when MgCO3 is used as a pH buffer in a batch reactor system. The use of MgCO3 as a neutralising
agent resulted in a biomass growth lag of about 8 h, followed by a sharp increase untill 15 h at which point the
biomass concentration remained constant throughout the fermentation run. The maximum biomass
concentration was 3.62 g/L. The fermentation ceased at a final SA concentration of 38.12 g/L and the SA yield
on glucose was 0.81 g/g from an initial glucose concentration of 60 g/L. At the end of the fermentation, 79 %
of the glucose as consumed. A residual glucose concentration of 12.84 g/L at the maximum SA concentration
indicated product-related inhibition. The biomass, acetic acid (AA), and formic acid (FA) concentrations were
incorrectly predicted by the model which implies that the use of MgCO3 as a buffer agent changed the
metabolic fluxes of the organism.