Glucose-6-phosphate dehydrogenase as a target for highly efficient fatty acid biosynthesis in microalgae by enhancing NADPH supply.
Metab Eng
; 41: 212-221, 2017 05.
Article
en En
| MEDLINE
| ID: mdl-28465173
ABSTRACT
Oleaginous microalgae have great prospects in the fields of feed, nutrition, biofuel, etc. However, biomass and lipid productivity in microalgae remain a major economic and technological bottleneck. Here we present a novel regulatory target, glucose-6-phosphate dehydrogenase (G6PD) from the pentose phosphate pathway (PPP), in boosting microalgal lipid accumulation. G6PD, involved in the formation of NADPH demanded in fatty acid biosynthesis as reducing power, was characterized in oleaginous microalga Phaeodactylum tricornutum. In G6PD overexpressing microalgae, transcript abundance of G6PD increased by 4.4-fold, and G6PD enzyme activity increased by more than 3.1-fold with enhanced NADPH production. Consequently, the lipid content increased by 2.7-fold and reached up to 55.7% of dry weight, while cell growth was not apparently affected. The fatty acid composition exhibited significant changes, including a remarkable increase in monounsaturated fatty acids C161 and C181 concomitant with a decrease in polyunsaturated fatty acids C205 and C226. G6PD was localized to the chloroplast and its overexpression stimulated an increase in the number and size of oil bodies. Proteomic and metabolomic analyzes revealed that G6PD play a key role in regulating pentose phosphate pathway and subsequently upregulating NADPH consuming pathways such as fatty acid synthesis, thus eventually leading to lipid accumulation. Our findings show the critical role of G6PD in microalgal lipid accumulation by enhancing NADPH supply and demonstrate that G6PD is a promising target for metabolic engineering.
Palabras clave
Texto completo:
1
Banco de datos:
MEDLINE
Asunto principal:
Diatomeas
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Ácidos Grasos Insaturados
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Microalgas
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Proteínas de Cloroplastos
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Glucosafosfato Deshidrogenasa
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NADP
Idioma:
En
Revista:
Metab Eng
Asunto de la revista:
ENGENHARIA BIOMEDICA
/
METABOLISMO
Año:
2017
Tipo del documento:
Article
País de afiliación:
China