Title: “Quantitative and qualitative effects of light on the growth of microalgae in dense crop and their production of molecules of interest”
Microalgae are a promising source of third generation biofuels. The interest on these photosynthetic microorganisms also lies within the extent of the spectrum of molecules that they can produce, such as proteins, pigments, and vitamins.
Nevertheless, further progress is still necessary to reduce the economic and environmental costs of cultivation processes and to ensure the viability of this sector. In particular, better understanding of the effect of light on the productivity of dense cultures is an essential step to optimize these processes.
The aim of this thesis is to study the quantitative and qualitative effects of light on growth and acclimation mechanisms of two species of microalgae with high biotechnological interest; Dunaliella salina and Tisochrysis lutea.
The first part of this thesis examines the response of Dunaliella salina to rapid light changes, by reproducing irradiance fluctuations typically experienced by microalgal cells in a highly turbid suspension in raceway ponds. In the second part, we analyzed the response of Dunaliella salina and Tisochrysis lutea to different light spectra. Our experimental and theoretical approach allowed us to identify the effect of colored light on productivity and pigment composition of microalgae. Furthermore, our results offer encouraging prospects for elevate understanding and use of light and improve the energy performance of these processes.
Dr. Claude Aflalo – Rapporteur
Pr. Yannick Huot – Rapporteur
Dr. Jean-Paul Cadoret – Examinateur
Dr. Bruno Sialve – Examinateur
Dr. Olivier Bernard – Co-directeur
Dr. Sophie Rabouille – Co-directrice
Dr. Antoine Sciandra – Directeur
Pr. Paul Nival – Président du jury