Mediterranean coastal lagoons such as the Etang de Berre are among the ecosystems most vulnerable to climate change, as they experience rapid and recurrent fluctuations in temperature, salinity, light and nutrient inputs under strong anthropogenic pressure. These shallow, semi-enclosed systems act as early-warning sentinels, where microbial communities respond rapidly to environmental forcing. In several Mediterranean lagoons, episodic “green water events” caused by dense phytoplankton proliferations increasingly disrupt ecosystem functioning and threaten aquaculture activities.
Among the taxa involved, the unicellular green microalga Picochlorum stands out for its exceptional tolerance to environmental variability and very high growth rates, making it both ecologically successful and attractive for climate-aligned biotechnologies such as CO₂ capture and biomass production (biofuel, bioplastics, etc.). However, large-scale cultures can collapse abruptly, as observed during the VASCO2 industrial pilot, highlighting a major bottleneck for ecosystem management and biotechnology.
VIROPICO-DOC aims to develop a mechanistic and predictive understanding of how environmental variability, algal physiology and viral infection jointly shape Picochlorum population dynamics in the Berre Lagoon in the context of global warming. Building on the recent discovery of giant viruses infecting Picochlorum (Picochloroviruses), the project will assess how temperature, salinity and irradiance modulate algal physiological performance and viral infection efficiency. Controlled laboratory experiments will identify strain-specific physiological responses and environmental “windows” favouring algal proliferation, viral regulation or coexistence.
These results will be confronted with seasonal in situ time series obtained through monthly sampling in partnership with GIPREB (non-academic), combining flow cytometry, qPCR and environmental genomics. The project also includes a three-month international secondment at the National Renewable Energy Laboratory (USA), providing advanced training in genetic transformation and genome editing of Picochlorum. By integrating laboratory experiments with long-term field monitoring, VIROPICO-DOC delivers actionable, mechanism-based insight into bloom initiation and collapse, supporting lagoon management under climate change and the development of more resilient microalgal biotechnologies.
Among the taxa involved, the unicellular green microalga Picochlorum stands out for its exceptional tolerance to environmental variability and very high growth rates, making it both ecologically successful and attractive for climate-aligned biotechnologies such as CO₂ capture and biomass production (biofuel, bioplastics, etc.). However, large-scale cultures can collapse abruptly, as observed during the VASCO2 industrial pilot, highlighting a major bottleneck for ecosystem management and biotechnology.
VIROPICO-DOC aims to develop a mechanistic and predictive understanding of how environmental variability, algal physiology and viral infection jointly shape Picochlorum population dynamics in the Berre Lagoon in the context of global warming. Building on the recent discovery of giant viruses infecting Picochlorum (Picochloroviruses), the project will assess how temperature, salinity and irradiance modulate algal physiological performance and viral infection efficiency. Controlled laboratory experiments will identify strain-specific physiological responses and environmental “windows” favouring algal proliferation, viral regulation or coexistence.
These results will be confronted with seasonal in situ time series obtained through monthly sampling in partnership with GIPREB (non-academic), combining flow cytometry, qPCR and environmental genomics. The project also includes a three-month international secondment at the National Renewable Energy Laboratory (USA), providing advanced training in genetic transformation and genome editing of Picochlorum. By integrating laboratory experiments with long-term field monitoring, VIROPICO-DOC delivers actionable, mechanism-based insight into bloom initiation and collapse, supporting lagoon management under climate change and the development of more resilient microalgal biotechnologies.
Supervisor
Dr. Guillaume Blanc, Institut Méditerranéen d’Océanologie (M.I.O), Aix-Marseille University
Co-Supervisor
Dr. Jean Alric, Institut de Biosciences et Biotechnologies d'Aix-Marseille (BIAM), Aix-Marseille University
Intersectoral partner
Syndicat Mixte GIPREB, France
International partner
National Renewable Energy Laboratory, Colorado - USA