Whole Cells as Biocatalysts in Organic Transformations

Abstract

Currently, the power and usefulness of biocatalysis in organic synthesis is undeniable, mainly due to the very high enantiomeric excess reached using enzymes, in an attempt to emulate natural processes. However, the use of isolated enzymes has some significant drawbacks, the most important of which is cost. The use of whole cells has emerged as a useful strategy with several advantages over isolated enzymes; for this reason, modern research in this field is increasing, and various reports have been published recently. This review surveys the most recent developments in the enantioselective reduction of carbon-carbon double bonds and prochiral ketones and the oxidation of prochiral sulfides using whole cells as biocatalytic systems.

Non-Conventional Yeasts as Sources of Ene-Reductases for the Bioreduction of Chalcones

“…The high chemoselectivity in the bioreduction of chalcones observed in the present study is probably not due to the lack of ADH activity in the yeast strains, rather to the steric hindrance given by the bulky phenyl substituents or to enzyme localization (not accessible to the substrates). Anyway, the bioreduction of C=O bond in ketones bearing bulky substituents was found in bacteria whole cells [43], as well as in other microorganism [44][45][46][47] such as algae, filamentous fungi, yeasts and in plant tissues [48].…”

The Hitchhiker's guide to biocatalysis: recent advances in the use of enzymes in organic synthesis

“…Enzymes can be sourced from plants, e.g. carrots 10 and soy beans, 11 fungi 12,13 (such as baker's yeast, lamentous fungi and mushrooms), bacteria 14 and archaea. 15 The early use of readily available enzymes from animal organs, e.g.…”

Enantioselective sulfoxidation using Streptomyces glaucescens GLA.0

“…In this case, only the S-enantiomer acts as a proton pump inhibitor and is used to treat gastric ulcers and gastroesophageal disorders. 3 Therefore, the stereoselective oxidation of organic suldes, the precursors for chiral sulfoxides, is receiving a growing interest nowadays. 4,5 Optically pure sulfoxides can be prepared via chemical or biological catalysis.…”

“…On the other hand, the use of whole cells, lysed cells, or cellular extracts as catalysts for asymmetric sulfoxidation reactions is a more attractive and a cheaper alternative since it avoids the need for adding expensive cofactors. 3 Fungi are widely used for catalyzing oxidation reactions compared to bacteria. [6][7][8] However, it was indicated that bacteria belonging to the genus Gordonia, Rhodococcus and Pseudomonas possess fairly high activity and enantioselectivity for a large number of suldes.…”