The cell potential at the open circuit, that is, the electromotive force (Eemf 5 Eeq,c–Eeq,a), was 0.6 V when 50 mM chlorophyll (as whole cell cyanobacteria) and 0.5 mM DMBQ were present in the anodic compartment, and 0.1 mM BOD and 0.5 mM ABTS2– in the cathodic compartmen