Metabolic engineering of Clostridium tyrobutyricum for n-butanol production: effects of CoA transferase.
Appl Microbiol Biotechnol
; 99(11): 4917-30, 2015 Jun.
Article
en En
| MEDLINE
| ID: mdl-25851718
ABSTRACT
The overexpression of CoA transferase (ctfAB), which catalyzes the reaction acetate/butyrate + acetoacetyl-CoA â acetyl/butyryl-CoA + acetoacetate, was studied for its effects on acid reassimilation and butanol biosynthesis in Clostridium tyrobutyricum (Δack, adhE2). The plasmid pMTL007 was used to co-express adhE2 and ctfAB from Clostridium acetobutylicum ATCC 824. In addition, the sol operon containing ctfAB, adc (acetoacetate decarboxylase), and ald (aldehyde dehydrogenase) was also cloned from Clostridium beijerinckii NCIMB 8052 and expressed in C. tyrobutyricum (Δack, adhE2). Mutants expressing these genes were evaluated for their ability to produce butanol from glucose in batch fermentations at pH 5.0 and 6.0. Compared to C. tyrobutyricum (Δack, adhE2) without expressing ctfAB, all mutants with ctfAB overexpression produced more butanol, with butanol yield increased to 0.22 - 0.26 g/g (vs. 0.10 - 0.13 g/g) and productivity to 0.35 g/l h (vs. 0.13 g/l h) because of the reduced acetate and butyrate production. The expression of ctfAB also resulted in acetone production from acetoacetate through a non-enzymatic decarboxylation.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Coenzima A Transferasas
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1-Butanol
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Clostridium tyrobutyricum
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Redes y Vías Metabólicas
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Ingeniería Metabólica
Idioma:
En
Revista:
Appl Microbiol Biotechnol
Año:
2015
Tipo del documento:
Article
País de afiliación:
Estados Unidos