Influences of light and oxygen conditions on photosynthetic bacteria macromolecule degradation: Different metabolic pathways

► Macromolecule degradation by photosynthetic bacteria under different light-oxygen conditions were studied. ► Macromolecule degradation was higher than 90% under different light-oxygen conditions. ► Oxygen was more benefit to macromolecule degradation, pollutants removal and biomass production. ► Different results of macromolecule degradation were caused by different light-oxygen metabolic pathways. ► Particular distinctions of metabolic pathways: final electronic acceptor, carbon utilization, biomass synthesis pathways.