Navigating microalgae under dynamic CO2 for waste-to-energy conversion.

Carbon capture is an important mitigation strategy for the reduction of carbon in the atmosphere. Microalgae can simultaneously capture CO2 and valorize biomass, turning waste streams into sustainable bioenergy solutions. However, microalgae struggle when CO2 is either too scarce or too abundant. The scalability of microalgal carbon capture requires the development of strains that can sustain productivity and carbon conversion under fluctuating CO2 levels. In this review, we reframe CO2 assimilation in microalgae as a dynamic system shaped by environmental variability. We highlight emerging strategies, including bicarbonate utilization, photobioreactor (PBR) innovation, molecular modeling, and genetic rewiring, that support scalable and specific waste-to-energy conversion. Together, these insights can drive the advancement of microalgal systems tailored for dynamic CO2 conditions.