A cost-effective microbial fuel cell to detect and select for photosynthetic electrogenic activity in algae and cyanobacteria

This work describes the development of an easily constructed, cost-effective photosynthetic microbial fuel cell design with highly reproducible electrochemical characteristics that can be used to screen algae and cyanobacteria for photosynthetic electrogenic activity. It is especially suitable for benthic varieties, those that attach to surfaces. The anode chamber of the cell uses disposable polystyrene sample bottles (pottles) with a simple-to-apply carbon coating. These chambers can be used to grow photosynthetic microorganisms without a cathode for electrochemical characterization or with a cathode and load applied to provide electrogenic selective pressure. The utility of the design for screening, isolating and analysing photosynthetic electrogenic microorganisms under a wide variety of conditions is demonstrated. Several genera of benthic cyanobacteria from both New Zealand and Antarctica were shown to be electrogenic including Pseudanabaena, Leptolyngbya, Chroocococales, Phormidesmis, Microcoleus, Nostoc and Phormidium. A benthic strain of the eukaryote Paulschulzia pseudovolvox (Chlorophyceae) was isolated and identified, which had very good electrogenic qualities.