Use of Immobilized Biocatalysts in Fluidized Bed Format

In a fluidized bed reactor, the substrate solution is fed from the lower end of the bed at a velocity high enough to lift the biocatalyst containing beads. Such reactors are especially valuable when the substrate solution contains particulate matter. The mass transfer in a fluidized bed is better as compared with packed beds. For optimum interaction between the biocatalyst and the substrate, the fluidization velocity needs to be optimized. This illustrative protocol describes a somewhat novel concept in which preparations of glucoamylase and pullulanase were entrapped in different populations of calcium alginate beads. These two entrapped enzyme preparations were premixed in the desired ratio to form a fluidized bed reactor that was used for hydrolysis of starch to glucose. The approach is different from coimmobilization because it allows one to blend the two enzymes in different ratios for optimum bioconversion.