In-depth exploration into the multifaceted regulatory mechanisms of carotenoid metabolism in microalgae.

Microalgae offer a sustainable and efficient way to produce natural carotenoids, with advantages such as easy cultivation, rapid growth, efficient photosynthesis, high yield, no competition for arable land, and utilization of CO2 and wastewater. With the growing demand for natural carotenoids, it is vital to explore ways to boost their production in microalgae. This requires a comprehensive understanding of the regulatory mechanisms underlying microalgal carotenoid metabolism. This review covers recent advances in the regulatory architecture of carotenoid biosynthesis in eukaryotic microalgae, highlighting how chemical and environmental cues reprogram transcription, post-translational modifications, chromatin state, epigenetic marks, and metabolic flux to balance carotenoid accumulation with cell growth and stress tolerance. Dissecting these multifaceted regulatory mechanisms by integrating multi-omics, molecular biology, and artificial intelligence (AI) tools will enable the rational engineering of high-quality intelligent microalgal strains with elevated carotenoid output, robust photosynthetic performance, and improved stress tolerance. This review provides new insights into the optimization of microalgal carotenoid production for industrial applications and the regulatory mechanisms of microalgal carotenoid metabolism.