US Patent 8007647 Retention of counterions in the separative bioreactor

A bioreactor with an anode and a cathode, and a plurality of reaction chambers each having an inlet and an outlet and each including a porous solid ion exchange wafer having ion-exchange resins. Each of the reaction chambers is interleaved between a cation exchange membrane and an anion exchange membrane or between either a cation or an anion exchange membrane and a bipolar exchange membrane. A product chamber is separated from one of the reaction chambers by either a cation or an anion exchange membrane. Recirculation mechanism is provided for transporting material between the reaction chamber inlets and outlets. A method of producing organic acids, amino acids, or amines using the separative bioreactor is disclosed.