Meta-Analysis of Abiotic Conditions Affecting Exopolysaccharide Production in Cyanobacteria

Background: cyanobacterial exopolysaccharides (EPSs) exhibit diverse biological and physicochemical properties, making them valuable for applications in environmental remediation, soil improvement, wastewater treatment, and bioenergy production. Results: the production of cyanobacterial EPSs is significantly influenced by various factors, including abiotic factors and strains. Recent research has focused on optimizing EPS production by regulating key abiotic factors such as light, temperature, pH, and nutritional conditions. This review systematically compiles and analyzes published data on the effects of abiotic factors on cyanobacterial EPS biosynthesis, with a focus on genus-specific responses. Using meta-analysis techniques, we provide a comprehensive overview of the key factors influencing EPS production. Light and nutrient conditions are the most significant factors affecting EPS production, with high light intensities and optimal nutrient conditions enhancing EPS synthesis. Optimal temperature ranges and pH levels are essential for maximizing EPS production, and cyanobacteria exhibit genus-specific responses to variations in these factors. The addition of specific nutrients, such as NaCl, trace metals (e.g., Mg, Zn, Cu), and elevated CO₂ levels, significantly impacts EPS production. Conclusions: the response to these factors varies among different cyanobacterial genera, highlighting the need for genus-specific optimization strategies. This review provides a theoretical basis for optimizing EPS production across diverse cyanobacterial genera and for understanding multi-factor interactions and practical applications in future research.