Hydrogen transfer pathways of the asymmetric reduction of α,β-unsaturated ketone mediated by baker’s yeast

Chu, Yu-De; Zhang, Ben Li; Silvestre, Virginie; Cheng, Jianbo

doi:10.1016/j.bioorg.2006.04.002

“…Allylic alcohols, such as geranyl diol I, in our study are used as substrates, which are transformed via the corresponding unsaturated aldehydes . During asymmetric reduction of carbonyl compounds by yeast it has been found that the hydrogen atoms were transferred from the cofactor NADPH and the hydrogen was provided by the added glucose or certain unidentified substances stored in the yeast cells . Thus, there are at least two different NADPH pools in yeast, which are differentially labeled with deuterium, when fermentation is carried out in deuterium oxide.…”

Section: Resultsmentioning

confidence: 82%

“…b For calculating the OAVs, an odor threshold value of 0.2 µg/L for (-)-cis-rose oxide was used (2, 3). hydrogen atoms were transferred from the cofactor NADPH and the hydrogen was provided by the added glucose or certain unidentified substances stored in the yeast cells (17). Thus, there are at least two different NADPH pools in yeast, which are differentially labeled with deuterium, when fermentation is carried out in deuterium oxide.…”

Section: Resultsmentioning

confidence: 99%

Stereoselective Formation of the Varietal Aroma Compound Rose Oxide during Alcoholic Fermentation

Koslitz

¹

,

Renaud

²

,

Kohler

³

et al. 2008

J. Agric. Food Chem.

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The potent aroma compound rose oxide was quantified in several white wines by a headspace solid-phase microextration stable isotope dilution assay (HS-SPME-SIDA) and the enantiomeric ratios of the cis diastereomers were determined by enantioselective capillary GC. The most odor-active stereoisomer (23)-cis-rose oxide was detectable in all investigated white wines ranging from 0.2 to 12 microg/L. However, its contribution to the overall aroma in some white wine varieties can be neglected as indicated by a low odor activity value (OAV). The highest concentrations were found in Gewürztraminer wines, confirming the importance of rose oxide as a varietal aroma compound in this variety. Surprisingly, the enantiomeric ratio of cis-rose oxide in all investigated wines was substantially lower than in nonfermented musts and in some wines almost racemic cis-rose oxide was detected. Fermentation studies with a model must that contained deuterated water revealed that yeast is capable of reducing the precursor 3,7-dimethyl octa-2,5-dien-1,7-diol (geranyl diol I) yielding 3,7-dimethyl-5-octen-1,7-diol (citronellyl diol I) that gives rise to cis- and trans-rose oxide after acid catalyzed cylization. The deuterium labeling pattern of the resulting rose oxide stereoisomers and a clearly detectable kinetic isotope effect indicate that at least two different reductive pathways in yeast exist that yield cis-rose oxide with different enantiomeric ratios altering the genuine enantiomeric ratio in grape musts. The presence of (+)-cis-rose oxides in wines can therefore be attributed to the reductive yeast metabolism during fermentation. This observation corroborates recent findings that the modification of terpene derived varietal aroma is an integral part of yeast metabolism and not only a simple hydrolytical process.

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“…In one case, reduction of the carbonyl group of acetoacetate occurred when about 5 mg yeast per mL (mixture of S. cerevisiae and S. bayanus) was used to catalyze the reaction [30]. In another report, reduction of the C=C double bond of (E)-3-ethyl-4-(3-pyridyl)-3-buten-2-one by Baker's yeast happened without the requirement of any auxiliary substrate as electron donor when a larger amount of yeast was used [31]. Both reports proposed certain unidentified substance stored inside the yeast cells might be used as electron donors for generating NADPH required by the oxidoreductases.…”

Section: Discussionmentioning

confidence: 99%

Production of bio-xylitol from D-xylose by an engineered Pichia pastoris expressing a recombinant xylose reductase did not require any auxiliary substrate as electron donor

Louie

¹

,

Louie

²

,

DenHartog

³

et al. 2021

Preprint

0

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Background: Xylitol is a five-carbon sugar alcohol that has numerous beneficial health properties. It has almost the same sweetness as sucrose but has lower energy value compared to the sucrose. Metabolism of xylitol is insulin independent and thus it is an ideal sweetener for diabetics. It is widely used in food products, oral and personal care, and animal nutrition as well. Here we present a two-stage strategy to produce bio-xylitol from D-xylose using a recombinant Pichia pastoris expressing a heterologous xylose reductase gene. The recombinant P. pastoris cells were first generated by a low-cost, standard procedure. The cells were then used as a catalyst to make the bio-xylitol from D-xylose.Results: P. pastoris expressing XYL1 from P. stipitis and gdh from B. subtilis demonstrated that the biotransformation was very efficient with as high as 80% (w/w) conversion within two hours. The whole cells could be re-used for multiple rounds of catalysis without loss of activity. Also, the cells could directly transform D-xylose in a non-detoxified hemicelluloses hydrolysate to xylitol at 70% (w/w) yield.Conclusions: We demonstrated here that the recombinant P. pastoris expressing xylose reductase could transform D-xylose, either in pure form or in crude hemicelluloses hydrolysate, to bio-xylitol very efficiently. This biocatalytic reaction happened without the external addition of any NAD(P)H, NAD(P)+, and auxiliary substrate as an electron donor. Our experimental design & findings reported here are not limited to the conversion of D-xylose to xylitol only but can be used with other many oxidoreductase reactions also, such as ketone reductases/alcohol dehydrogenases and amino acid dehydrogenases, which are widely used for the synthesis of high-value chemicals and pharmaceutical intermediates.

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“…In one case, reduction of the carbonyl group of acetoacetate occurred when about 5 mg yeast per mL (mixture of S. cerevisiae and S. bayanus) was used to catalyze the reaction [38]. In another report, reduction of the C=C double bond of (E)-3-ethyl-4-(3-pyridyl)-3-buten-2one by Baker's yeast happened without the requirement of any auxiliary substrate as electron donor when a larger amount of yeast was used [39]. Both reports proposed certain unidenti ed substance stored inside the yeast cells might be used as electron donors for generating NADPH required by the oxidoreductases.…”

Section: Discussionmentioning

confidence: 99%

Production of bio-xylitol from D-xylose by an engineered Pichia pastoris expressing a recombinant xylose reductase did not require any auxiliary substrate as electron donor

Louie

¹

,

Louie

²

,

DenHartog

³

et al. 2020

Preprint

View full text Add to dashboard Cite

Background: Xylitol is a five-carbon sugar alcohol that has numerous beneficial health properties. It has almost the same sweetness as sucrose but has lower energy value compared to the sucrose. Metabolism of xylitol is insulin independent and thus it is an ideal sweetener for diabetics. It is widely used in food products, oral and personal care, and animal nutrition as well. Here we present a two-stage strategy to produce bio-xylitol from D-xylose using a recombinant Pichia pastoris expressing a heterologous xylose reductase gene. The recombinant P. pastoris cells were first generated by a low-cost, standard procedure. The cells were then used as a catalyst to make the bio-xylitol from D-xylose.Results: P. pastoris expressing XYL1 from P. stipitis and gdh from B. subtilis demonstrated that the biotransformation was very efficient with as high as 80% (w/w) conversion within two hours. The whole cells could be re-used for multiple rounds of catalysis without loss of activity. Also, the cells could directly transform D-xylose in a non-detoxified hemicelluloses hydrolysate to xylitol at 70% (w/w) yield.Conclusions: We demonstrated here that the recombinant P. pastoris expressing xylose reductase could transform D-xylose, either in pure form or in crude hemicelluloses hydrolysate, to bio-xylitol very efficiently. This biocatalytic reaction happened without the external addition of any NAD(P)H, NAD(P)+, and auxiliary substrate as an electron donor. Our experimental design & findings reported here are not limited to the conversion of D-xylose to xylitol only but can be used with other many oxidoreductase reactions also, such as ketone reductases/alcohol dehydrogenases and amino acid dehydrogenases, which are widely used for the synthesis of high-value chemicals and pharmaceutical intermediates.

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Hydrogen transfer pathways of the asymmetric reduction of α,β-unsaturated ketone mediated by baker’s yeast

Cited by 13 publications

References 17 publications

Stereoselective Formation of the Varietal Aroma Compound Rose Oxide during Alcoholic Fermentation

Stereoselective Formation of the Varietal Aroma Compound Rose Oxide during Alcoholic Fermentation

Production of bio-xylitol from D-xylose by an engineered Pichia pastoris expressing a recombinant xylose reductase did not require any auxiliary substrate as electron donor

Production of bio-xylitol from D-xylose by an engineered Pichia pastoris expressing a recombinant xylose reductase did not require any auxiliary substrate as electron donor

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Hydrogen transfer pathways of the asymmetric reduction of α,β-unsaturated ketone mediated by baker’s yeast

Cited by 13 publications

References 17 publications

Stereoselective Formation of the Varietal Aroma Compound Rose Oxide during Alcoholic Fermentation

Stereoselective Formation of the Varietal Aroma Compound Rose Oxide during Alcoholic Fermentation

Production of bio-xylitol from&nbsp;D-xylose by an engineered&nbsp;Pichia pastoris&nbsp;expressing a recombinant xylose reductase did not require any auxiliary substrate as electron donor

Production of bio-xylitol from D-xylose by an engineered Pichia pastoris expressing a recombinant xylose reductase did not require any auxiliary substrate as electron donor

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Product

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About

Production of bio-xylitol from D-xylose by an engineered Pichia pastoris expressing a recombinant xylose reductase did not require any auxiliary substrate as electron donor