PRODUCTION OF BUTANOL IN A CONTINUOUS PACKED BED REACTOR OF CLOSTRIDIUM ACETOBUTYLICUM

The contribute reports on butanol production by means of biofilm of Clostridium acetobutylicum ATCC 824A. The establishment of a stable biofilm and the progress of Acetone-Butanol-Ethanol (ABE) production by immobilized cells are demonstrated in a packed bed reactor using hydrophobic plastic carriers. The medium was a solution of lactose and yeast extract to emulate the cheese whey, an abundant lactose-rich wastewater. The reactor was operated under controlled conditions with respect to pH and dilution rate. The pH values ranged between 4 and 6, the dilution rate between 0.54 1/h and 2.4 1/h (2.5 time the maximum specific growth rate assessed for suspended cells). The conversion process was characterized in terms of concentration of suspended cells and metabolites and of mass of biofilm. Results were worked out to assess the rate of ABE production.