Microbial production of a biofuel (acetone-butanol-ethanol) in a continuous bioreactor: impact of bleed and simultaneous product removal.
Acetone butanol ethanol (ABE) was produced in an integrated continuous one-stage fermentation and gas stripping product recovery system using Clostridium beijerinckii BA101 and fermentation gases (CO(2) and H(2)). In this system, the bioreactor was fed with a concentrated sugar solution (250-500 g L(-1) glucose). The bioreactor was bled semi-continuously to avoid accumulation of inhibitory chemicals and products. The continuous system was operated for 504 h (21 days) after which the fermentation was intentionally terminated. The bioreactor produced 461.3 g ABE from 1,125.0 g total sugar in 1 L culture volume as compared to a control batch process in which 18.4 g ABE was produced from 47.3 g sugar. These results demonstrate that ABE fermentation can be operated in an integrated continuous one-stage fermentation and product recovery system for a long period of time, if butanol and other microbial metabolites in the bioreactor are kept below threshold of toxicity.
Department of Animal Sciences, Ohio State Agricultural Research and Development Center (OARDC), The Ohio State University, 305 Gerlaugh Hall, 1680 Madison Avenue, Wooster, OH 44691, USA. ezeji.1@osu.edu
Thaddeus Chukwuemeka
TC
Ezeji
Nasib
N
Qureshi
Hans Peter
HP
Blaschek
D000096:Acetone / Q000302:isolation & purification / Q000378:metabolism*; D056804:Biofuels / Q000382:microbiology*; D019149:Bioreactors / Q000382:microbiology*; D000440:Butanols / Q000302:isolation & purification / Q000378:metabolism*; D046970:Clostridium beijerinckii / Q000378:metabolism*; D000431:Ethanol / Q000302:isolation & purification / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism*
D056804:Biofuels; D000440:Butanols; D000096:Acetone; D000431:Ethanol; D005947:Glucose