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Enoate reductases from non conventional yeasts: Bioconversion, cloning, and functional expression in Saccharomyces cerevisiae

Paper ID Volume ID Publish Year Pages File Format Full-Text
23808 43474 2011 7 PDF Available
Title
Enoate reductases from non conventional yeasts: Bioconversion, cloning, and functional expression in Saccharomyces cerevisiae
Abstract

Old yellow enzymes (OYEs, EC 1.6.99.1) are flavin-dependent oxidoreductases that catalyze the stereoselective trans-hydrogenation of the double bond, representing a promising alternative to metal-based catalysis. Bioconversion of ketoisophorone (KIP) by 28 non-conventional yeasts belonging to 16 different species was investigated. Growing cells of most of the strains reduced KIP via OYE and showed high stereoselectivity, producing R-levodione as major product. Competition by carbonyl reductase (CR) activity was observed in several strains. The best performing yeasts belong to Candida castellii, Kazachstania spencerorum and Kluyveromyces marxianus exhibited yields of levodione ≥77% up to 95% e.e., and. Candida freyschussii, the sole strain lacking the OYE gene, reduced KIP only to unsaturated alcohols via CR. Nine unedited OYE genes were cloned, sequenced, and heterologously expressed in Saccharomyces cerevisiae BY4741ΔOye2, a mutant that showed negligible OYE and CR activities. Compared with the corresponding wild-type yeasts, growing cells of the recombinant strains bioconverted KIP with improved yields of OYE products, minor competition by CR activity, and lower enantioselectivity. In particular, resting cells of recombinant S. cerevisae presented the best performance in KIP bioconversion. Based on the results herein reported, selected strains of non-conventional yeasts and novel OYE genes can be profitably used as innovative biocatalysts in asymmetric reductions.

► Detailed analysis of stereoselective reduction of ketosiophorone by 28 non conventional yeasts. ► Cloning and sequenceing of 9 novel genes encoding old yellow enzyme. ► Heterologous expression in S. cerevisiae. ► Recombinant whole-cells biocatalysts for asymmetric reduction.

Keywords
Enoate reductase; Old yellow enzyme; Non-conventional yeasts; Whole-cell biocatalysts; Asymmetric reduction
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Enoate reductases from non conventional yeasts: Bioconversion, cloning, and functional expression in Saccharomyces cerevisiae
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Publisher
Database: Elsevier - ScienceDirect
Journal: Journal of Biotechnology - Volume 156, Issue 4, 20 December 2011, Pages 279–285
Authors
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Subjects
Physical Sciences and Engineering Chemical Engineering Bioengineering
Get Full-Text Now
Don't Miss Today's Special Offer
Price was $35.95
You save - $31
Price after discount Only $4.95
100% Money Back Guarantee
Full-text PDF Download
Online Support
Any Questions? feel free to contact us