TY - JOUR
T1 - Toward an understanding of lipid and starch accumulation in microalgae
T2 - A proteomic study of Neochloris oleoabundans cultivated under N-limited heterotrophic conditions
AU - Morales-Sánchez, Daniela
AU - Kyndt, John
AU - Ogden, Kimberly
AU - Martinez, Alfredo
N1 - Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2016/12/1
Y1 - 2016/12/1
N2 - Neochloris oleoabundans is an oleaginous microalga of biotechnological and commercial interest. A proteomic study was performed to compare the abundance of proteins under two different culture conditions: preferential lipid accumulation and preferential carbohydrate accumulation. When N. oleoabundans was cultivated under long periods of nitrogen starvation, the acyl carrier protein and the protein biotin carboxylase from the lipid synthesis pathway were found to be upregulated. The central metabolism pathways were also found to be highly activated to redirect the carbon flow toward pyruvate dehydrogenase and ATP synthesis. Pyruvate dehydrogenase was upregulated to supply the precursors for lipid production. Furthermore, in the pentose phosphate pathway, specifically glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were upregulated to supply reducing power in the form of NADPH for lipid synthesis and inorganic nitrogen assimilation. Carbohydrate synthesis-related enzymes that channel carbon to starch and sugar synthesis, such as UDP-glucose pyrophosphorylase and starch synthase, were upregulated when short durations of nitrogen limitation were applied during N. oleoabundans cultivation. However, ADP-glucose pyrophosphorylase was upregulated under preferential lipid accumulation conditions, indicating that under prolonged nitrogen starvation conditions, this enzyme potentially hydrolyzes starch chains to channel the carbon flow to lipid synthesis, which indicates a dual function of this protein.
AB - Neochloris oleoabundans is an oleaginous microalga of biotechnological and commercial interest. A proteomic study was performed to compare the abundance of proteins under two different culture conditions: preferential lipid accumulation and preferential carbohydrate accumulation. When N. oleoabundans was cultivated under long periods of nitrogen starvation, the acyl carrier protein and the protein biotin carboxylase from the lipid synthesis pathway were found to be upregulated. The central metabolism pathways were also found to be highly activated to redirect the carbon flow toward pyruvate dehydrogenase and ATP synthesis. Pyruvate dehydrogenase was upregulated to supply the precursors for lipid production. Furthermore, in the pentose phosphate pathway, specifically glucose 6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were upregulated to supply reducing power in the form of NADPH for lipid synthesis and inorganic nitrogen assimilation. Carbohydrate synthesis-related enzymes that channel carbon to starch and sugar synthesis, such as UDP-glucose pyrophosphorylase and starch synthase, were upregulated when short durations of nitrogen limitation were applied during N. oleoabundans cultivation. However, ADP-glucose pyrophosphorylase was upregulated under preferential lipid accumulation conditions, indicating that under prolonged nitrogen starvation conditions, this enzyme potentially hydrolyzes starch chains to channel the carbon flow to lipid synthesis, which indicates a dual function of this protein.
KW - Glucose
KW - Lipid and carbohydrate anabolism
KW - Neochloris oleoabundans
KW - Nitrogen-limitation
KW - Proteomics
KW - heterotrophic growth
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U2 - 10.1016/j.algal.2016.09.006
DO - 10.1016/j.algal.2016.09.006
M3 - Article
AN - SCOPUS:84988419482
SN - 2211-9264
VL - 20
SP - 22
EP - 34
JO - Algal Research
JF - Algal Research
ER -