Production of Ethanol from Cellulose Using Clostridum thermocellum

Clostridium thermocellum was used to produce ethanol from cellulose in a continuous system. Batch fermentations were first performed to observe the effects of buffers and agitation on generation time and ethanol production. Continuous fermentations were carried out at 60°C and pH 7 using pure cellulose as the limiting substrate. The maximum ethanol concentrations produced with 1.5 and 3% cellulose fermenting liquid were 0.3 and 0.9% respectively. The yield of ethanol was about 0.3 grams per gram of cellulose consumed. While the continuous fermentation of cellulose with Clostridium thermocellum appears to be feasible, it may not be economically promising due to the slow growth of the organism.