How Past Carbon Shapes the Future: The Hidden Resilience of Photogranules in Wastewater Treatment

Oxygenic photogranules (OPGs)—compact microbial aggregates primarily composed of photosynthetic cyanobacteria and associated bacteria—have emerged as promising, eco-friendly agents in wastewater treatment. These naturally formed granules are capable of simultaneously removing carbon, nitrogen, and phosphorus while generating oxygen through photosynthesis, reducing the need for energy-intensive mechanical aeration. However, the extent to which their metabolic activity adapts to fluctuating environmental conditions, such as variations in light intensity or carbon availability, has remained largely unexplored.