A Kinetic Model of Cellobiose Fermentation by Resting (Nongrowing) Clostridium thermocellum JW20 Cells

Clostridium thermocellum has been proposed as a microorganism for ethanol fermentation from biomass because of its ability to degrade cellulose and produce ethanol from the products of cellulose degradation. The commercial use of this microbe is hindered by its low ethanol tolerance and low ethanol yield. The resting cells can alleviate these biological limitations as is done with the current commercial microbes. A comprehensive kinetic model was developed to predict multiple-product concentrations in batch cellobiose fermentation by the resting C. thermocellum cells. The model adequately represented the multi-product fermentation activity of resting C. thermocellum cells. The major discrepancies between model predictions and observed data were the underprediction of glucose concentration and overprediction of lactate prediction, but these only occured under cellobiose limitation.