Algae-Bacteria cooperated microbial ecosystem: A self-circulating semiartificial photosynthetic purifying strategy

Harnessing solar energy to provide sustainable power for microbial fuel cell (MFC) operation holds great potential. In this study, a semiartificial photosynthetic self-circulating MFC ecosystem is successfully established through the collaboration of electrogenic microorganisms and photosynthetic algae. The ecosystem can operate continuously without carbon sources added and produces a voltage of 150 mV under irradiation. The irradiation doubles the maximum power density of the ecosystem, reaching 8.07 W/m2 compared to dark conditions. The results of electrochemical analysis suggest a higher diffusion capacity or faster electron replenishment ability within the ecosystem. Under irradiation, the ecosystem demonstrates a 2.25-fold increase in chromium (Cr(Ⅵ)) removal rate compared to dark conditions. Finally, the results of 16S rRNA amplicon sequencing indicates an increase in the relative abundance of strict and facultative aerobic electroactive bacteria in the ecosystem. The ecosystem offers a novel, self-sustaining approach to address the challenges of energy recovery and environmental pollution.