Bisepoxide Cross-Linked Enzyme Aggregates-New Immobilized Biocatalysts for Selective Biotransformations

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. The missing linker: Glycerol diglycidyl ether is applied as a cross‐linker for cross‐linked enzyme aggregates (CLEAs) of various enzymes such as lipases and phenylalanine ammonia lyases. The bisepoxide CLEAs prove to be efficient and robust biocatalysts surpassing the performance of the glutaraldehyde CLEAs.