Controlling Ethanol Use in Chain Elongation by CO2 Loading Rate
메타 데이터
바이오화학분류
바이오정밀화학
용매
화학제품
연료
기타
화장품용 기능성소재
향수
계면활성제⁄증점제
기타
의료용 화학소재
치료제
식품첨가제
논문
Controlling Ethanol Use in Chain Elongation by CO2 Loading Rate
학술지
Environmental science & technology
저자명
Roghair, Mark; Hoogstad, Tim; Strik, David P.B.T.B.; Plugge, Caroline M.; Timmers, Peer H.A.; Weusthuis, Ruud A.; Bruins, Marieke E.; Buisman, Cees J. N.
초록
<P/><P>Chain elongation is an open-culture biotechnological process which converts volatile fatty acids (VFAs) into medium chain fatty acids (MCFAs) using ethanol and other reduced substrates. The objective of this study was to investigate the quantitative effect of CO<SUB>2</SUB> loading rate on ethanol usages in a chain elongation process. We supplied different rates of CO<SUB>2</SUB> to a continuously stirred anaerobic reactor, fed with ethanol and propionate. Ethanol was used to upgrade ethanol itself into caproate and to upgrade the supplied VFA (propionate) into heptanoate. A high CO<SUB>2</SUB> loading rate (2.5 L<SUB>CO2</SUB>·L<SUP>–1</SUP>·d<SUP>–1</SUP>) stimulated excessive ethanol oxidation (EEO; up to 29%) which resulted in a high caproate production (10.8 g·L<SUP>–1</SUP>·d<SUP>–1</SUP>). A low CO<SUB>2</SUB> loading rate (0.5 L<SUB>CO2</SUB>·L<SUP>–1</SUP>·d<SUP>–1</SUP>) reduced EEO (16%) and caproate production (2.9 g·L<SUP>–1</SUP>·d<SUP>–1</SUP>). Heptanoate production by VFA upgrading remained constant (∼1.8 g·L<SUP>–1</SUP>·d<SUP>–1</SUP>) at CO<SUB>2</SUB> loading rates higher than or equal to 1 L<SUB>CO2</SUB>·L<SUP>–1</SUP>·d<SUP>–1</SUP>. CO<SUB>2</SUB> was likely essential for growth of chain elongating microorganisms while it also stimulated syntrophic ethanol oxidation. A high CO<SUB>2</SUB> loading rate must be selected to upgrade ethanol (e.g., from lignocellulosic bioethanol) into MCFAs whereas lower CO<SUB>2</SUB> loading rates must be selected to upgrade VFAs (e.g., from acidified organic residues) into MCFAs while minimizing use of costly ethanol.</P>