Immobilization of enzymes based on hydrophobic interaction. III. Adsorbent substituent density and its impact on the immobilization of beta-amylase.

Hexyl-groups have been introduced into crosslinked Sepharose 6B, yielding gels with degrees of substitution which range from 0.02 to 0.70 mol hexyl-side chain per mole galactose residue. The gels were exposed to beta-amylase in solution, and the resulting adsorbates indicated a monotonic increase in adsorption capacity with an increasing hexyl-content. Adsorbate activity, by contrast, displayed a maximum for a carrier gel with a hexyl-galactose ratio of 0.51. Adsorbates based on gels with different hexyl-content were used in column reactors for continuous maltose production from a soluble starch substrate.