NOVELTY - Device comprises a first electrode compartment is anode compartment, and a second electrode compartment is cathode (7) compartment, with a quantity of an anode fluid containing an electrochemically oxidizable substrate and quantity of a cathode fluid containing an electrochemically reducible substrate, where anode or cathode comprises electrochemically active micro-organisms (2) is adapted as several capacitive bioelectrode particles (1) combined with a number of charge conductors (5), and where the number of charge conductors.    USE - As a device useful in performing electrochemical reaction for generating electrical energy, producing hydrogen and methane (claimed).    ADVANTAGE - The active micro-organisms in device resist the charging and discharging cycles which they undergo on capacitive electrode particles. The device minimizes the loss of electricity production due to the cathode electrode overpotential; and minimizes ohmic losses by the bioelectrode particles were there discharged to the charge conductor which was placed closely to the membrane, thus ion transport distance through the membrane was minimal.    DETAILED DESCRIPTION - Device comprises a first electrode compartment is anode compartment, and a second electrode compartment is cathode (7) compartment, with a quantity of an anode fluid containing an electrochemically oxidizable substrate and optional further compounds in the anode compartment, a quantity of a cathode fluid containing an electrochemically reducible substrate and optional further compounds in the cathode compartment, and further an anode at least partially in contact with the anode fluid in the anode compartment and a cathode at least partially in contact with the cathode fluid in the cathode compartment, where the anode and cathode are electrically connected and on the surface of the anode and the cathode a catalyst is present for respective catalysis of the electrochemical conversion of the electrochemically oxidizable substrate via an electrochemical oxidation reaction and catalysis of the electrochemical conversion of the electrochemically reducible substrate via an electrochemical reduction reaction, which catalyst comprises electrochemically active micro-organisms on at least one of the anode or cathode, where anode or cathode comprises electrochemically active micro-organisms (2) is adapted as several capacitive bioelectrode particles (1) combined with a number of charge conductors (5), the capacitive bioelectrode particles containing a first electrically conductive material with electrochemically active microorganisms on it, and where the number of charge conductors, of a second electrically conductive material, are incorporated in the electrical connection between the anode and cathode and where means are also provided for causing movement of the bioelectrode particles relative to the number of charge conductors such that electrical contact between bioelectrode particles and the number of charge conductors can be regulated, so that charging or discharging of bioelectrode particles is possible at the number of charge conductors. The bioelectrode particles are in the form of foam particles, powder particles, grains, needles, brush bristles or strips. The micro-organisms are selected from Geobacter sulferreducens, Geobacter metallireducens, Shewanella putrefaciens, Rhodoferax ferrireducens. An INDEPENDENT CLAIM is included for performing an electrochemical reaction involving providing the device; causing movement of the bioelectrode particles relative to the number of charge conductors such that charging or discharging of bioelectrode particles on the number of charge conductors can take place; allowing the electrochemical oxidation reaction in the electrochemical reduction reaction to proceed; and electric current flows between the cathode and anode.    DESCRIPTION OF DRAWING(S) - The figures shows basis of capacitive bioanode outline of the concept of the capacitive bioelectrode.    Bioelectrode particle (1)    Micro-organisms (2)    Charge conductor (5)    Cathode (7)    Power consumer (9)