How to Turn Yeast Cells into a Sustainable and Switchable Biocatalyst? On-Demand Catalysis of Ketone Bioreduction or Acyloin Condensation

Abstract

In this study, yeast strains were screened and immobilized in a form preserving the multifaceted biocatalytic activity. Immobilization of the silica-supported whole cells of various yeasts, such as Lodderomyces elongisporus, Pichia carsonii, Candida norvegica, and Debaryomyces fabryi, by sol−gel entrapment resulted in easy-to-handle biocatalysts that mediated efficiently different types of synthetic reactions. In the present study, the enantiotope selective reduction of prochiral ketones 1a−d and the acyloin condensation of benzaldehyde 3 were studied, representing two remarkably diverse types of biotransformation. The yeast cell biocatalystsin the presence of fresh or recovered NADH cofactorcould be applied for continuous-flow bioreduction of ketones 1a−d with moderate to good yields (20 to 92%) and excellent enantiomeric purity (>99%). Immobilized L. elongisporus and P. carsonii cells could also mediate acyloin condensation of benzaldehyde 3 in batch as well as in continuousflow mode. The switchable biocatalytic activity of the immobilized yeast cells was demonstrated by consecutive biotransformations under continuous-flow conditions involving reduction of phenylacetone 1a to (S)-phenylpropane-2-ol [(S)-2a] first, followed by conversion of benzaldehyde 3 to (R)-1-hydroxy-1-phenylpropan-2-one [(R)-4] and reduction of 1a to (S)-2a again by using the same packed-bed bioreactor.

Preparation of Hybrid Sol-Gel Materials Based on Living Cells of Microorganisms and Their Application in Nanotechnology

“…Immobilized microorganisms are able to effectively dispose of organic compounds such as 4-phenylbutan-2-amine or heptan-2-amine [ 107 ] in a continuous flow mode. At the same time, selective reduction of prochiral ketones and acyloin condensation of benzaldehyde with yields from moderate 20% to great 99% were observed during the joint immobilization of yeast cells of Lodderomyceselongisporus , Pichia carsonii , Candida norvegica , and Debaryomyces fabryi in a sol-gel matrix [ 108 ].…”

Alcohol Dehydrogenases as Catalysts in Organic Synthesis

“…However, because of weaker binding forces involved in immobilisation, deactivation of the enzyme by conformational distortions is less likely in comparison with other approaches. Entrapment of ADHs with various gelating materials comprising silica gels (Musa et al, 2007;Nagy-Gyor et al, 2018;Liu et al, 2019;Nagy-Győr et al, 2019) polyvinyl alcohol (Krasnan et al, 2016;Petrovicova et al, 2018;Yildirim et al, 2019) poly ethyleneglycol (Schmieg et al, 2019) superabsorbers (Heidlindemann et al, 2014;Adebar and Groger, 2020), alginates (Milagre et al, 2005(Milagre et al, , 2006He et al, 2017;Nasario et al, 2019), metal organic frameworks (MOFs) (Carucci et al, 2018;Ye et al, 2020) or liposomes (Yoshimoto et al, 2008) has been reported.…”

Glucose/Furfural Substrate Mixtures in Non‐Engineered Yeast: Potential for Massive Rerouting of Fermentation to C−C Bond Formation on Furfural

“…In addition to the use of purified and immobilized enzyme preparations, biocatalysis can be pursued with intact cells [3,16–18] . In the case of yeast, the cells may be available commercially at near‐negligible costs.…”