초록
Two rounds of acetone-butanol-ethanol (ABE) fermentation under slight pressure were carried out in the continuous and closed-circulating fermentation (CCCF) system. Spores of the clostridium were observed and counted, with the maximum number of 2.1x10<SUP>8</SUP> and 2.3x10<SUP>8</SUP>ml<SUP>-1</SUP> separately. The fermentation profiles were comparable with that at atmospheric pressure, showing an average butanol productivity of 0.14 and 0.13gL<SUP>-1</SUP>h<SUP>-1</SUP>. Moreover, the average gas productivities of 0.28 and 0.27LL<SUP>-1</SUP>h<SUP>-1</SUP> were obtained in two rounds of CCCF, and the cumulative gas production of 52.64 and 25.92LL<SUP>-1</SUP> were achieved, with the hydrogen volume fraction of 41.43% and 38.08% respectively. The results suggested that slight pressures have no obvious effect on fermentation performance, and also indicated the significance and feasibility of gas recovery in the continuous ABE fermentation process.