Modification of Alcalase SphereZyme™ by entrapment in LentiKats^® to impart improved particle stability

Abstract

SphereZymes are self-immobilised enzyme particles that are formed by cross-linking enzymes while in an emulsion. The resultant spherical particles can be isolated and applied in biocatalytic reactions.Modification of the cross-linking procedure to utilise a polyamine polymer (polyethyleneimine), in conjunction with glutaraldehyde, enhanced the activity of Alcalase^® SphereZyme preparations towards both large (azocasein) and small substrates (p-nitrophenyl acetate), resulting in 16.6% and 53.7% retention in the activity, respectively, after immobilisation. To improve the filterability of these particles, we attempted two strategies. One was to include rigid polyethyleneimine–silica particles in the SphereZymes, and the second was to entrap SphereZymes in rigid PVA hemispheres (LentiKats^®). Both methods greatly enhanced the filterability and robustness of the SphereZymes, with the entrapped particles being the easiest to handle.

Keywords::

• immobilisation
• protease
• enzyme
• biocatalysis
• LentiKats^®

Acknowledgements

A special thanks to Dr R. Gordon of ZA Biotech for advice on commercial requirements for enzyme immobilisation, and to Dr. D. Visser of CSIR Bio sciences for technical support.

Declaration of interest: The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.