Conversion of starch into ethanol by Clostridium thermohydrosulfuricum

Production of ethanol from starch by Clostridium thermohydrosulfuricum was compared with that from glucose, fructose or maltose in batch fermentations. Optimal substrate concentration and pH for ethanol production were determined. The rate of ethanol production on starch was about the same as that on glucose or fructose and overall yields were also similar (about 1.6 mol ethanol per mol glucose or glucose equivalent). Maltose was not an effective substrate for growth and ethanol production.