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Keywords:

  • biotransformations;
  • cross-linked enzyme aggregate;
  • enzyme catalysis;
  • immobilization;
  • lipase;
  • phenylalanine ammonia-lyase

Abstract

Glycerol diglycidyl ether (GDE) is a convenient and inexpensive bisepoxide cross-linker as demonstrated by the preparation of cross-linked enzyme aggregates (CLEAs) from two enzyme classes. The GDE CLEAs of lipase from Pseudomonas fluorescens (AK), lipase from Burkholderia cepacia (PS), and lipase B from Candida antarctica (CaL B) as well as of phenylalanine ammonia-lyase (PAL) from Petroselinum crispum demonstrated improved properties as compared with their glutaraldehyde (GA) cross-linked counterparts. Ultrasonication studies indicated that the GDE CLEAs of lipase PS and PAL were mechanically more stable than the GA CLEAs. In the kinetic resolution of rac-1-phenylethanol, the catalytic activity of the GDE–lipase CLEAs (U=69.6, 134.8, and 127.4 U g−1 for AK, CaL B, and PS prepared at 22 °C, respectively) surpassed that of the corresponding GA–lipase CLEAs (U=24.4, 131.0, and 119.2 U g−1 for AK, CaL B, and PS prepared at 22 °C, respectively). The GDE co-CLEAs from PAL and bovine serum albumin (BSA) could be recycled at least three times if used for the stereoselective ammonia addition in 6 M ammonia to (E)-3-(thiophen-2-yl)acrylic acid, whereas the recycling of the conventional GA–PAL CLEAs from this medium failed.