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A genetic and metabolic approach to redirection of biochemical pathways of Clostridium butyricum for enhancing hydrogen production
Author(s) -
Cai Guiqin,
Jin Bo,
Monis Paul,
Saint Christopher
Publication year - 2013
Publication title -
biotechnology and bioengineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.136
H-Index - 189
eISSN - 1097-0290
pISSN - 0006-3592
DOI - 10.1002/bit.24596
Subject(s) - clostridium butyricum , butyrate , chemistry , biochemistry , alcohol dehydrogenase , metabolic pathway , ethanol , cofactor , nad+ kinase , yield (engineering) , lactate dehydrogenase , clostridium , hydrogen production , bacteria , enzyme , fermentation , catalysis , biology , materials science , metallurgy , genetics
Clostridium butyricum, a well known H 2 producing bacterium, produces lactate, butyrate, acetate, ethanol, and CO 2 as its main by‐products from glucose. The conversion of pyruvate to lactate, butyrate and ethanol involves oxidation of NADH. It was hypothesized that the NADH could be increased if the formation of these by‐products could be eliminated, resulting in enhancing H 2 yield. Herein, this study aimed to establish a genetic and metabolic approach for enhancing H 2 yield via redirection of metabolic pathways of a C. butyricum strain. The ethanol formation pathway was blocked by disruption of aad (encoding aldehyde‐alcohol dehydrogenase) using a ClosTron plasmid. Although elimination of ethanol formation alone did not increase hydrogen production, the resulting aad ‐deficient mutant showed approximately 20% enhanced performance in hydrogen production with the addition of sodium acetate. This work demonstrated the possibility of improving hydrogen yield by eliminating the unfavorable by‐products ethanol and lactate. Biotechnol. Bioeng. 2013; 110: 338–342. © 2012 Wiley Periodicals, Inc.