Maximizing the production of acetone—butanol in an alginate bead fluidized bed reactor using clostridium acetobutylicum

Low volumetric solvent productivities are one of the characteristics of an acetone‐butanol fermentation by C. acetobutylicum. A calcium alginate immobilized continuous culture was used in a novel gas‐sparged reactor to strip the solvents from the aqueous phase and reduce their toxicity. A dilution rate of 0.07 h −1 was found to give maximum solvent productivity at 0.58 g dm −3 h −1 , although at 0.12 h −1 the productivity was slightly lower. In order to increase glucose uptake by the culture, feed glucose concentrations were increased over time to attempt to acclimatize the culture. This resulted in a productivity as high as 0.72 g dm −3 h −1 although this production rate was found to be unstable.