The paradoxes hidden behind the Droop model highlighted by a metabolic approach

We propose metabolic models for the haptophyte microalgae Tisochrysis lutea with different possible organic carbon excretion mechanisms. These models—based on the DRUM (Dynamic Reduction of Unbalanced Metabolism) methodology—are calibrated with an experiment of nitrogen starvation under day/night cy...

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Autores principales: Baroukh, Caroline, Mairet, Francis, Bernard, Olivier
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9442053/
https://www.ncbi.nlm.nih.gov/pubmed/36072315
http://dx.doi.org/10.3389/fpls.2022.941230
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author Baroukh, Caroline
Mairet, Francis
Bernard, Olivier
author_facet Baroukh, Caroline
Mairet, Francis
Bernard, Olivier
author_sort Baroukh, Caroline
collection PubMed
description We propose metabolic models for the haptophyte microalgae Tisochrysis lutea with different possible organic carbon excretion mechanisms. These models—based on the DRUM (Dynamic Reduction of Unbalanced Metabolism) methodology—are calibrated with an experiment of nitrogen starvation under day/night cycles, and then validated with nitrogen-limited chemostat culture under continuous light. We show that models including exopolysaccharide excretion offer a better prediction capability. It also gives an alternative mechanistic interpretation to the Droop model for nitrogen limitation, which can be understood as an accumulation of carbon storage during nitrogen stress, rather than the common belief of a nitrogen pool driving growth. Excretion of organic carbon limits its accumulation, which leads to a maximal C/N ratio (corresponding to the minimum Droop N/C quota). Although others phenomena—including metabolic regulations and dissipation of energy—are possibly at stake, excretion appears as a key component in our metabolic model, that we propose to include in the Droop model.
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spelling pubmed-94420532022-09-06 The paradoxes hidden behind the Droop model highlighted by a metabolic approach Baroukh, Caroline Mairet, Francis Bernard, Olivier Front Plant Sci Plant Science We propose metabolic models for the haptophyte microalgae Tisochrysis lutea with different possible organic carbon excretion mechanisms. These models—based on the DRUM (Dynamic Reduction of Unbalanced Metabolism) methodology—are calibrated with an experiment of nitrogen starvation under day/night cycles, and then validated with nitrogen-limited chemostat culture under continuous light. We show that models including exopolysaccharide excretion offer a better prediction capability. It also gives an alternative mechanistic interpretation to the Droop model for nitrogen limitation, which can be understood as an accumulation of carbon storage during nitrogen stress, rather than the common belief of a nitrogen pool driving growth. Excretion of organic carbon limits its accumulation, which leads to a maximal C/N ratio (corresponding to the minimum Droop N/C quota). Although others phenomena—including metabolic regulations and dissipation of energy—are possibly at stake, excretion appears as a key component in our metabolic model, that we propose to include in the Droop model. Frontiers Media S.A. 2022-08-22 /pmc/articles/PMC9442053/ /pubmed/36072315 http://dx.doi.org/10.3389/fpls.2022.941230 Text en Copyright © 2022 Baroukh, Mairet and Bernard. https://creativecommons.org/licenses/by/4.0/This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Plant Science
Baroukh, Caroline
Mairet, Francis
Bernard, Olivier
The paradoxes hidden behind the Droop model highlighted by a metabolic approach
title The paradoxes hidden behind the Droop model highlighted by a metabolic approach
title_full The paradoxes hidden behind the Droop model highlighted by a metabolic approach
title_fullStr The paradoxes hidden behind the Droop model highlighted by a metabolic approach
title_full_unstemmed The paradoxes hidden behind the Droop model highlighted by a metabolic approach
title_short The paradoxes hidden behind the Droop model highlighted by a metabolic approach
title_sort paradoxes hidden behind the droop model highlighted by a metabolic approach
topic Plant Science
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9442053/
https://www.ncbi.nlm.nih.gov/pubmed/36072315
http://dx.doi.org/10.3389/fpls.2022.941230
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