Advances in organic acid production using cyanobacteria: strategies and applications

Cyanobacteria, the photosynthetic microorganisms, offer a promising platform for sustainable organic acid production because of their ability to fix atmospheric carbon dioxide and harness light energy. The global demand for bio-based organic acids is rising in response to stricter environmental regulations and the growing emphasis on sustainable, fossil-free production methods. Due to the multifunctional roles and economic significance, organic acids have attracted significant attention both in research and industrial applications. Microbial synthesis of organic acids using fungi, bacteria, and cyanobacteria offers a sustainable alternative to petrochemical routes. Notably, recent advances in synthetic biology and metabolic engineering have enabled cyanobacteria and other photoautotrophic organisms to be explored as sustainable platforms for CO2-based production, offering greener alternatives to conventional fermentation processes. This review provides a comprehensive overview of the metabolic pathways involved in organic acid synthesis in cyanobacteria, highlighting key genetic modifications and environmental factors that influence production efficiency. It also examines the optimization of cultivation parameters, including light intensity, nutrient composition, and CO2 levels, which have significantly enhanced productivity. In addition, genetic and systems-level strategies for enhancing organic acid production are discussed. Insights from recent omics-based studies have deepened our understanding of the underlying mechanisms, laying a solid foundation for future research and the rational design of more robust cyanobacterial strains. Furthermore, this review discusses the industrial applications of organic acids in multiple sectors, emphasizing how cyanobacteria-based biosynthesis contributes to carbon footprint reduction and sustainable biomanufacturing. Despite these advancements, challenges such as genetic stability, low yields, by-product formation, and bioreactor scalability remain major obstacles for commercial production. Finally, recent case studies illustrate successful strategies in strain engineering and process optimization, highlighting the growing potential of cyanobacteria-based production systems.