Front Cover: Co‐immobilized Whole Cells with ω‐Transaminase and Ketoreductase Activities for Continuous‐Flow Cascade Reactions (ChemBioChem 17/2018)

Abstract

The front cover picture shows a novel biocatalyst for cascade biotransformations comprising co‐immobilized cells with two different biocatalytic activities. A rational strategy based on an improved sol–gel process using hollow silica microspheres as a supporting additive was applied to co‐immobilize various whole cells with different biocatalytic activities directly after harvesting fermentations. Entrapment of Escherichia coli cells with Chromobacterium violaceum ω‐transaminase activity and Lodderomyces elongisporus cells with ketoreductase activity in presence of silica microspheres (depicted here as footballs) provided a biocatalyst with easy recovery, long‐term storability and good mechanical stability. The co‐immobilized whole‐cell biocatalyst could perform a reaction cascade converting racemic 4‐phenylbutan‐2‐amine or heptan‐2‐amine to a nearly equimolar mixture of enantiomerically pure (R)‐amine and the corresponding (S)‐alcohol even in continuous‐flow mode. More information can be found in the communication by G. Hornyánszky, L. Poppe, et al. on page 1845 in Issue 17, 2018 (DOI: 10.1002/cbic.201800286).