Effect of overexpression of malate dehydrogenase on succinic acid production in Escherichia coli NZN111 / 生物工程学报
Chinese Journal of Biotechnology
; (12): 1005-1012, 2011.
Article
en Zh
| WPRIM
| ID: wpr-324509
Biblioteca responsable:
WPRO
ABSTRACT
Escherichia coli NZN111 is a double mutant with lactate dehydrogenase (ldhA) and pyruvate formate-lyase (pflB) inactivated. Under anaerobic conditions, disequilibrium of coenzyme NADH and NAD+ causes Escherichia coli NZN111 losing the glucose utilizing capability. In this study, we constructed a recombinant strain E. coli NZN111/pTrc99a-mdh and overexpressed the mdh gene with 0.3 mmol/L of IPTG under anaerobic fermentation condition in sealed bottles. The specific malate dehydrogenase (MDH) activity in the recombinant strain was 14.8-fold higher than that in E. coli NZN111. The NADH/ NAD+ ratio decreased from 0.64 to 0.26 and the concentration of NAD+ and NADH increased 1.5-fold and 0.2-fold respectively. Under anaerobic conditions, the recombinant strain possessed the capability of growth and glucose absorption. We took dual-phase fermentation for succinate production. After the dry cell weight (DCW) reached 6.4 g/L under aerobic conditions, the cell culture was changed to anaerobic conditions. After 15 h, 14.75 g/L glucose was consumed and succinic acid reached 15.18 g/L. The yield of succinic acid was 1.03 g/g Glu and the productivity of succinic acid was 1.012 g/(L x h).
Texto completo:
1
Índice:
WPRIM
Asunto principal:
Recombinación Genética
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Acetiltransferasas
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Proteínas Recombinantes
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Ácido Succínico
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Escherichia coli
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Técnicas de Inactivación de Genes
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Fermentación
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Genética
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Glucosa
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Anaerobiosis
Idioma:
Zh
Revista:
Chinese Journal of Biotechnology
Año:
2011
Tipo del documento:
Article