Process for the Stereoselective Biotransformation of Acetoacetic Acid Esters Using Yeasts

Rohner, Markus; Münch, Thomas A.; Sonnleitner, Bernhard; Fiechter, Armin

doi:10.3109/10242429008992047

Cited by 17 publications

(2 citation statements)

References 16 publications

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“…For more detailed information, see Figures S10 and S11 To apply the developed droplet microfluidics-IMS system for the whole-cell catalysis by yeast cells, the reduction of EAA to EHB was chosen as an exemplary biotransformation (Figure 3). 73,74 Before coupling the nL-sized reaction vessels to IMS, the capability of the applied custom-built drift-tube instrument had to be tested to monitor the course of the reaction. Although the structures of the substrate and the product are very similar, direct infusion ESI-IMS measurements showed that both analytes can be distinguished and separated (Figure 3) with a peak-to-peak resolution of R p-p = 0.9 (R p-p = 1.18 (t d EHB − t d EAA )/(w 0.5 EHB + w 0.5 EAA ), with the analyte drift time t d and the peak width at half-maximum w 0.5 ).…”

Section: ■ Experimental Sectionmentioning

confidence: 99%

Coupling Droplet Microfluidics with Ion Mobility Spectrometry for Monitoring Chemical Conversions at Nanoliter Scale

et al. 2021

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We introduce the coupling of droplet microfluidics and ion mobility spectrometry (IMS) to address the challenges of label-free and chemical-specific detection of compounds in individual droplets. In analogy to the established use of mass spectrometry, droplet−IMS coupling can be also achieved via electrospray ionization but with significantly less instrumental effort. Because IMS instruments do not require high-vacuum systems, they are very compact, cost-effective, and robust, making them an ideal candidate as a chemical-specific end-of-line detector for segmented flow experiments. Herein, we demonstrate the successful coupling of droplet microfluidics with a custom-built high-resolution drift tube IMS system for monitoring chemical reactions in nL-sized droplets in an oil phase. The analytes contained in each droplet were assigned according to their characteristic ion mobility with limit of detections down to 200 nM to 1 μM and droplet frequencies ranging from 0.1 to 0.5 Hz. Using a custom sheath flow electrospray interface, we have further achieved the chemical-specific monitoring of a biochemical transformation catalyzed by a few hundred yeast cells, at single droplet level.

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Section: ■ Experimental Sectionmentioning

confidence: 99%

Coupling Droplet Microfluidics with Ion Mobility Spectrometry for Monitoring Chemical Conversions at Nanoliter Scale

et al. 2021

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“…Even if such protocols are described in sufficient detail to be reproduced, quantitative understanding of the results and scaling-up is difficult because several process parameters change simultaneously. In only a few publications, optimization of the reduction of ethyl 3-oxobutanoate while controlling and measuring the most important param- eters has been reported (Kometani et al, 1993(Kometani et al, , 1994Rohner et al, 1990;Wipf et al, 1983). From these publications a useful protocol for controlled EOB addition, leading to high enantiomeric excess values of the product can be obtained.…”

Section: Introductionmentioning

confidence: 99%

Influence of the ethanol and glucose supply rate on the rate and enantioselectivity of 3‐oxo ester reduction by baker's yeast

Chin-Joe

Straathof

Pronk

et al. 2001

Biotech & Bioengineering

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Baker's-yeast-mediated reductions of ketones hold great potential for the industrial production of enantiopure alcohols. In this article we describe the stoichiometry and kinetics of asymmetric ketone reduction by cell suspensions of bakers' yeast (Saccharomyces cerevisiae). A system for quantitative analysis of 3-oxo ester reduction was developed and allowed construction of full mass and redox balances as well as determination of the influence of different process parameters on aerobic ketone reduction. The nature of the electron donor (ethanol or glucose) and its specific consumption rate by the biomass (0-1 mol.kg dw(-1).h(-1)) affected the overall stoichiometry and rate of the process and the final enantiomeric excess of the product. Excess glucose as the electron donor, i.e. a very high consumption rate of glucose, resulted in a high rate of alcoholic fermentation, oxygen consumption, and biomass formation and therefore causing low efficiency of glucose utilization. Controlled supply of the electron donor at the highest rates applied prevented alcoholic fermentation but still resulted in biomass formation and a high oxygen requirement, while low rates resulted in a more efficient use of the electron donor. Low supply rates of ethanol resulted in biomass decrease while low supply rates of glucose provided the most efficient strategy for electron donor provision and yielded a high enantiomeric excess of ethyl (S)-3-hydroxybutanoate. In contrast to batchwise conversions with excess glucose as the electron donor, this strategy prevented by-product formation and biomass increase, and resulted in a low oxygen requirement.

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Organische Synthese — wohin?

Seebàch

1990

Angewandte Chemie

205

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Process for the Stereoselective Biotransformation of Acetoacetic Acid Esters Using Yeasts

Cited by 17 publications

References 16 publications

Coupling Droplet Microfluidics with Ion Mobility Spectrometry for Monitoring Chemical Conversions at Nanoliter Scale

Coupling Droplet Microfluidics with Ion Mobility Spectrometry for Monitoring Chemical Conversions at Nanoliter Scale

Influence of the ethanol and glucose supply rate on the rate and enantioselectivity of 3‐oxo ester reduction by baker's yeast

Organische Synthese — wohin?

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