The dynamic of light regulation in outdoor microalgae cultures

Microalgae are one of the organism models used in the Gain4Crops projects to smooth the translation of results to the final target plant, the sunflower. But they are an exciting subject also as they represent a sustainable source of biomass with applications in several fields, from food to pharmaceutical. Still, their cultivation scale-up needs some refinement to become economically competitive and improve the positive impact on the environment.

In a recent study from Tomas Morosinotto’s laboratory at the University of Padua, current knowledge of the regulation of photosynthesis and its implications for maximizing the productivity of microalgal biomass are discussed. For example, by enhancing microalgae’s ability to exploit light exposure better, we can also increase biomass yield.

In fact, light is a highly variable environmental parameter: it constantly changes with the seasons, time of day, and weather conditions. Microalgae have several regulatory mechanisms to handle such dynamic conditions, which, however, are not adapted to respond to artificial fluctuations typical of large-scale cultures. In addition to natural fluctuations, self-shading among individual cells is observed in large-scale cultures. This wildly uneven exposure to light is further unbalanced due to shuffling: cells, in fact, shift and undergo abrupt changes in light exposure. While the regulation of photosynthesis has so far been studied mainly under controlled laboratory conditions, these mechanisms have a substantial impact on outdoor cultivation. Gain4Crops hopes to contribute to exploring this subject – more advances are needed to understand how to exploit light exposure in real-life microalgae cultivation.

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