Robust and recyclable cross-linked enzyme aggregates of sucrose isomerase for isomaltulose production

A novel cross-linked enzyme aggregates (CLEAs) catalyst was produced by precipitation and cross-linking sucrose isomerase (SIase) for isomaltulose production. The effects of precipitants and cross-linkers on the catalytic performance of the CLEAs were first evaluated. Then, bovine serum albumin (BSA) was used as additive and two immobilized enzymes, cross-linked SIase aggregates (CLSIAs) and CLSIAs-BSA were obtained. All the immobi-lized preparations exhibited superior thermal stability, pH tolerance, and storage stability compared to the soluble SIase, and showed excellent reusability. These samples still retained more than 61% of their initial ac-tivity after ten reuse cycles, with CLSIAs-BSA retaining up to 91.7%. The conversion ratios of sucrose into iso-maltulose using CLSIAs-BSA reached 88.4 and 81.2% with sucrose and sugar cane juice as substrate, respectively. Therefore, CLSIAs are a highly effective biocatalyst for the preparation of isomaltulose with great potential for industrial applications.