Effects of light colors on the biochemical composition of Scenedesmus obliquus.

This study explores the impact of different light colors on the population growth, photosynthesis, and biochemical composition of Scenedesmus obliquus. Literature shows various biotechnological solutions to mitigate the environmental problems caused by greenhouse gas emissions from environmentally unsustainable processes, and microalgae cultures have emerged as a promising technology with the potential to support diverse production chains. In this context, Scenedesmus has demonstrated considerable potential. The present study presents a straightforward approach to enhance protein production in S. obliquus through the strategic manipulation of light wavelengths, with the potential for practical implementation. The paper goes on to outline future research directions for integrating light control technologies, emphasizing the potential for maximizing biomolecules accumulation. Cell density and viability, growth rates, carbohydrates and proteins, total carotenoids and photosynthesis inferred by pulse amplitude modulated fluorescence (PhytoPAM) were evaluated. Blue light was identified as optimal for total proteins production (5.5 µg/mL vs. 2.5-3.8 µg/mL in other light colors), while white light showed promise for carotenoid accumulation (0.160 µg/mL vs. 0.10-0.13 in other light colors). Notably, the observed variations in the light spectrum did not result in any significant changes in the maximum growth rates (1.08-1.13), underscoring the robustness of the organism under study. Photosynthetic parameters remained unaffected by light quality, indicating a robust photosynthetic machinery (qP 1.0, NPQ 0.2, and effective quantum yield 0.58). These findings contribute to our understanding of algal biology and provide practical insights for biotechnological applications, paving the way for sustainable solutions.