The microalgae imperative: linking aquatic physiology, evolution, and sustainability for a changing planet

Abstract

Microalgae are increasingly recognized as pivotal agents in addressing the intertwined challenges of climate change, food security, and energy transition. Their extraordinary physiological diversity and evolutionary capacity position them at the nexus of natural biogeochemical regulation and engineered sustainability solutions. This review explores how microalgal physiology, spanning carbon fixation, nutrient cycling, and stress metabolism, supports their roles in circular bioeconomy systems and global sustainability initiatives. We highlight how physiological efficiency and physiological flexibility underpin the potential of microalgae for CO ₂ capture, wastewater valorization, biofuel production, and high-value bioproduct synthesis. Yet, we also emphasize the importance of integrating physiological constraints, ecological feedbacks, and adaptive potential into the design of sustainable cultivation systems. Bridging cellular mechanisms with global-scale processes will be essential to ensure the evolutionary stability and environmental safety of future algal technologies. Building on John Raven’s foundational insights into photosynthetic energetics and resource acquisition, we advocate for an integrative framework linking algal physiology, evolution, and sustainability science to realize the “microalgae imperative” for a sustainable Anthropocene.