Metabolic Engineering of Clostridium cellulovorans to Improve Butanol Production by Consolidated Bioprocessing.
ACS Synth Biol
; 9(2): 304-315, 2020 02 21.
Article
em En
| MEDLINE
| ID: mdl-31940438
ABSTRACT
Clostridium cellulovorans DSM 743B can produce butyrate when grown on lignocellulose, but it can hardly synthesize butanol. In a previous study, C. cellulovorans was successfully engineered to switch the metabolism from butyryl-CoA to butanol by overexpressing an alcohol aldehyde dehydrogenase gene adhE1 from Clostridium acetobutylicum ATCC 824; however, its full potential in butanol production is still unexplored. In the study, a metabolic engineering approach based on a push-pull strategy was developed to further enhance cellulosic butanol production. In order to accomplish this, the carbon flux from acetyl-CoA to butyryl-CoA was pulled by overexpressing a trans-enoyl-coenzyme A reductase gene (ter), which can irreversibly catalyze crotonyl-CoA to butyryl-CoA. Then an acid reassimilation pathway uncoupled with acetone production was introduced to redirect the carbon flow from butyrate and acetate toward butyryl-CoA. Finally, xylose metabolism engineering was implemented by inactivating xylR (Clocel_0594) and araR (Clocel_1253), as well as overexpressing xylT (CA_C1345), which is expected to supply additional carbon and reducing power for CoA and butanol synthesis pathways. The final engineered strain produced 4.96 g/L of n-butanol from alkali extracted corn cobs (AECC), increasing by 235-fold compared to that of the wild type. It serves as a promising butanol producer by consolidated bioprocessing.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Clostridium cellulovorans
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Butanóis
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Engenharia Metabólica
Idioma:
En
Revista:
ACS Synth Biol
Ano de publicação:
2020
Tipo de documento:
Article