Stressing cyanobacteria for enhanced production of bulk and value-added chemicals

Cyanobacteria, ancient photosynthetic prokaryotes capable of directly converting CO₂ and solar energy into various chemicals through photosynthesis, have drawn great attention as a photosynthetic biomanufacturing platform. To enhance the production of various chemicals, multi-dimensional engineering strategies spanning genetic modification to process optimization have been developed. Notably, stress activation strategies, characterized by their strong controllability and the absence of transgenic risks, have recently attracted significant attention. These strategies could reprogram native metabolic networks, effectively redirecting photosynthetic flux toward targeted biosynthesis pathways while maintaining cellular viability, thereby boosting the production of both bulk and value-added chemicals. This review summarizes recent advances in stress-driven cyanobacterial chemical production, including compatible solutes, pigments and biofuels. We dissect regulatory mechanisms at transcriptional, translational, and enzymatic levels, and discuss challenges and potential strategies for enhancing the large-scale industrial production of cyanobacteria under stress conditions.