The magnetically stabilised fluidised bed bioreactor: a tool for improved mass transfer in immobilised enzyme systems?

Studies were carried out using novel magnetic carrier particles in a magnetically stabilized fluidized bed (MSFB) to determine the degree of liquid phase mass transfer enhancement achievable over a range of magnetic field strengths. The carrier particles, beads of κ-carrageenan incorporating magnetite, ranging in size from 0.25 to 1 mm are used for enzyme immobilization. Results using a 113 mm diameter column showed that a more than five-fold increase in liquid velocity could be achieved when a current of 40 A was applied to a single magnetic coil. The “escape” velocity of the particles from the bed was found to be proportional to the magnetic field intensity squared. The effect was further increased (almost doubled) by inserting a steel rod into the centre of the bed.