Behavior of bioelectrocatalytic currents in electrolysis cells using immobilized Synechocystsis sp PCC6714 within poly-ion complex on glassy carbon electrodes

A cyanobacteria, Synechocystis sp. PCC6714, was immobilized within a poly-i on complex on a glassy carbon electrode. When 2-hydroxy-1,4-naphthoquinone (HNQ) was used as a mediator, bioelectrocatalytic currents were significant ly produced in the dark. Under illumination, they decreased when bubbling t he gas phase in the electrolysis cells with N-2 gas due to reoxidation of H NQ by the photosynthetically evolved oxygen. By bubbling the reaction solut ions using N-2 gas, the current increased under illumination and remained h igher than in the dark.