Elimination of D-lactate synthesis increases poly(3-hydroxybutyrate) and ethanol synthesis from glycerol and affects cofactor distribution in recombinant Escherichia coli
The effect of eliminating D-lactate synthesis in poly(3-hydroxybutyrate) (PHB)-accumulating recombinant Escherichia coli (K24K) was analyzed using glycerol as a substrate. K24KL, an ldhA derivative, produced more biomass and had altered carbon partitioning among the metabolic products, probably due...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2010 |
| País: | Argentina |
| Institución: | Universidad Nacional de Buenos Aires. Facultad de Ciencias Exactas y Naturales |
| Repositorio: | Biblioteca Digital (UBA-FCEN) |
| Idioma: | inglés |
| OAI Identifier: | paperaa:paper_00992240_v76_n22_p7400_Nikel |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00992240_v76_n22_p7400_Nikel |
| Access Level: | acceso abierto |
| Palabra clave: | Carbon partitioning Carbon precursors Cofactors D-lactate Fed-batch cultures Metabolic products Poly(3-hydroxybutyrate) Recombinant Escherichia coli Reducing power Batch cell culture Escherichia coli Ethanol Substrates Glycerol alcohol carbon glycerol hydroxybutyric acid lactate dehydrogenase lactic acid nicotinamide adenine dinucleotide nicotinamide adenine dinucleotide phosphate poly(3 hydroxybutyric acid) poly-beta-hydroxybutyrate polyester biomass ester ethanol fecal coliform partitioning recombination article bioreactor chemistry genetics growth, development and aging metabolism time Biomass Bioreactors Carbon Hydroxybutyrates Lactate Dehydrogenases Lactic Acid Metabolic Networks and Pathways NAD NADP Polyesters Time Factors |
| Sumario: | The effect of eliminating D-lactate synthesis in poly(3-hydroxybutyrate) (PHB)-accumulating recombinant Escherichia coli (K24K) was analyzed using glycerol as a substrate. K24KL, an ldhA derivative, produced more biomass and had altered carbon partitioning among the metabolic products, probably due to the increased availability of carbon precursors and reducing power. This resulted in a significant increase of PHB and ethanol synthesis and a decrease in acetate production. Cofactor measurements revealed that cultures of K24K and K24KL had a high intracellular NADPH content and that the NADPH/NADP+ ratio was higher than the NADH/NAD+ ratio. The ldhA mutation affected cofactor distribution, resulting in a more reduced intracellular state, mainly due to a further increase in NADPH/NADP+. In 60-h fed-batch cultures, K24KL reached 41.9 g · liter-1 biomass and accumulated PHB up to 63% ± 1% (wt/wt), with a PHB yield on glycerol of 0.41 ± 0.03 g · g-1, the highest reported using this substrate. © 2010, American Society for Microbiology. |
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