Characterization of the VOC Promoter That Is Active Under Low-Salinity Conditions in the Diatom <i>Phaeodactylum tricornutum</i>

Microalgae such as <i>Phaeodactylum tricornutum</i> are promising cell biofactories for the production of high-value molecules, including monoclonal antibodies (mAbs). However, to date, the production of mAbs in <i>P. tricornutum</i> using the inducible nitrate reductase (NR)...

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Main Authors: Charlotte Toustou, Carole Plasson, Marie-Christine Kiefer-Meyer, Muriel Bardor
Format: Article
Language:English
Published: MDPI AG 2025-04-01
Series:Marine Drugs
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Online Access:https://www.mdpi.com/1660-3397/23/5/185
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author Charlotte Toustou
Carole Plasson
Marie-Christine Kiefer-Meyer
Muriel Bardor
author_facet Charlotte Toustou
Carole Plasson
Marie-Christine Kiefer-Meyer
Muriel Bardor
author_sort Charlotte Toustou
collection DOAJ
description Microalgae such as <i>Phaeodactylum tricornutum</i> are promising cell biofactories for the production of high-value molecules, including monoclonal antibodies (mAbs). However, to date, the production of mAbs in <i>P. tricornutum</i> using the inducible nitrate reductase (NR) promoter has yielded only a limited amount of mAbs. Therefore, the identification of a robust promoter that produces high yields of mAbs is crucial for the development of a cost-effective expression system. To date, only a few endogenous promoters have been characterized in <i>P. tricornutum</i>. In this study, we identified thirty-three potential “strong” endogenous promoters based on our previously published transcriptomic data from the <i>P. tricornutum</i> Pt3 strain. These putative promoter sequences were cloned into an episomal vector and fused to the gene encoding enhanced green fluorescent protein (eGFP). Their strength was assessed by measuring eGFP fluorescence, which reflects the level of eGFP protein expression. Of the thirty-three promoters, thirteen were able to successfully drive eGFP protein expression. Among them, the best results were obtained with the VOC promoter, which allowed a significant increase in eGFP expression compared to that induced by the NR promoter. These results contribute to the identification of new genetic tools that can be used in future studies to increase the yield of production of recombinant proteins in <i>P. tricornutum</i> at an industrial scale.
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spelling doaj-art-5456dec2816a4de6874ae3ea000e8efd2025-08-20T01:56:17ZengMDPI AGMarine Drugs1660-33972025-04-0123518510.3390/md23050185Characterization of the VOC Promoter That Is Active Under Low-Salinity Conditions in the Diatom <i>Phaeodactylum tricornutum</i>Charlotte Toustou0Carole Plasson1Marie-Christine Kiefer-Meyer2Muriel Bardor3Laboratoire Glycobiologie et Matrice Extracellulaire Végétale (GlycoMEV) UR4358, University of Rouen Normandie (UNIROUEN), Normandie Université, 76821 Mont-Saint-Aignan, FranceLaboratoire Glycobiologie et Matrice Extracellulaire Végétale (GlycoMEV) UR4358, University of Rouen Normandie (UNIROUEN), Normandie Université, 76821 Mont-Saint-Aignan, FranceLaboratoire Glycobiologie et Matrice Extracellulaire Végétale (GlycoMEV) UR4358, University of Rouen Normandie (UNIROUEN), Normandie Université, 76821 Mont-Saint-Aignan, FranceLaboratoire Glycobiologie et Matrice Extracellulaire Végétale (GlycoMEV) UR4358, University of Rouen Normandie (UNIROUEN), Normandie Université, 76821 Mont-Saint-Aignan, FranceMicroalgae such as <i>Phaeodactylum tricornutum</i> are promising cell biofactories for the production of high-value molecules, including monoclonal antibodies (mAbs). However, to date, the production of mAbs in <i>P. tricornutum</i> using the inducible nitrate reductase (NR) promoter has yielded only a limited amount of mAbs. Therefore, the identification of a robust promoter that produces high yields of mAbs is crucial for the development of a cost-effective expression system. To date, only a few endogenous promoters have been characterized in <i>P. tricornutum</i>. In this study, we identified thirty-three potential “strong” endogenous promoters based on our previously published transcriptomic data from the <i>P. tricornutum</i> Pt3 strain. These putative promoter sequences were cloned into an episomal vector and fused to the gene encoding enhanced green fluorescent protein (eGFP). Their strength was assessed by measuring eGFP fluorescence, which reflects the level of eGFP protein expression. Of the thirty-three promoters, thirteen were able to successfully drive eGFP protein expression. Among them, the best results were obtained with the VOC promoter, which allowed a significant increase in eGFP expression compared to that induced by the NR promoter. These results contribute to the identification of new genetic tools that can be used in future studies to increase the yield of production of recombinant proteins in <i>P. tricornutum</i> at an industrial scale.https://www.mdpi.com/1660-3397/23/5/185<i>Phaeodactylum tricornutum</i>microalgaepromotersepisomal expressionsynthetic biologyrecombinant proteins
spellingShingle Charlotte Toustou
Carole Plasson
Marie-Christine Kiefer-Meyer
Muriel Bardor
Characterization of the VOC Promoter That Is Active Under Low-Salinity Conditions in the Diatom <i>Phaeodactylum tricornutum</i>
Marine Drugs
<i>Phaeodactylum tricornutum</i>
microalgae
promoters
episomal expression
synthetic biology
recombinant proteins
title Characterization of the VOC Promoter That Is Active Under Low-Salinity Conditions in the Diatom <i>Phaeodactylum tricornutum</i>
title_full Characterization of the VOC Promoter That Is Active Under Low-Salinity Conditions in the Diatom <i>Phaeodactylum tricornutum</i>
title_fullStr Characterization of the VOC Promoter That Is Active Under Low-Salinity Conditions in the Diatom <i>Phaeodactylum tricornutum</i>
title_full_unstemmed Characterization of the VOC Promoter That Is Active Under Low-Salinity Conditions in the Diatom <i>Phaeodactylum tricornutum</i>
title_short Characterization of the VOC Promoter That Is Active Under Low-Salinity Conditions in the Diatom <i>Phaeodactylum tricornutum</i>
title_sort characterization of the voc promoter that is active under low salinity conditions in the diatom i phaeodactylum tricornutum i
topic <i>Phaeodactylum tricornutum</i>
microalgae
promoters
episomal expression
synthetic biology
recombinant proteins
url https://www.mdpi.com/1660-3397/23/5/185
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