Synthesis of (S)-Tert-Butyl 3-Hydroxybutyrate by Asymmetric Reduction of Tert-Butyl Acetoacetate with Saccharomyces cerevisiae B5

2013 ◽  
Vol 704 ◽  
pp. 12-17
Author(s):  
Zhi Min Ou ◽  
Wen Fei Feng ◽  
Li Xu
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Substrate Concentration ◽  
Asymmetric Reduction ◽  
Optical Purity ◽  
Lower Amount ◽  
High Optical Purity ◽  
Initial Substrate ◽  
Initial Ph ◽  
H 30 ◽  
Initial Substrate Concentration

S)-tert-butyl 3-hydroxybutyrate was synthesized by asymmetric reduction of tert-butyl acetoacetate with Saccharomyces cerevisiae B5 as catalyst. The enantiometric excess of (S)-tert-butyl 3-hydroxybutyrate increased with addition of more amount of substrate. High optical purity of product can be obtained when 6 g/L chloroform was used as inhibitor. The optimum reduction time, temperature, and initial pH of reaction mixture were 60 h, 30 °C, and 6.2. Addition of more biomass and lower amount of substrate helped to get high conversion. Conversion and enantiometric excess of product reached 100% when initial substrate concentration and biomass were 2.0 g/L and 140 g/L with 6 g/L chloroform as inhibitor.

Optimization of the asymmetric synthesis of chiral aromatic alcohol using freeze-dried carrots as whole-cell biocatalysts

2016 ◽  
Vol 5 (2) ◽  
Author(s):  
Hilal Celik Kazici ◽  
Emine Bayraktar ◽  
Ülkü Mehmetoglu
Keyword(s):  
Reaction Time ◽  
Organic Synthesis ◽  
Substrate Concentration ◽  
Asymmetric Reduction ◽  
Alcohol Dehydrogenases ◽  
Enantiomerically Pure ◽  
Initial Substrate ◽  
Freeze Dried ◽  
Reduction Of Ketones ◽  
Initial Substrate Concentration

AbstractAsymmetric reduction of ketones is an important transformation in organic synthesis, because chiral carbinols are useful bioactive compounds. In this study, bioreduction of acetophenone (ACP) for production of enantiomerically pure (S)-1-phenyl-ethanol was investigated and freeze-dried carrots were used as a source of alcohol dehydrogenases (ADHs). However, production of product was investigated systematically using response surface methodology (RSM). Before RSM, the effects of the initial substrate concentration, reaction time, temperature and pH on the bioreduction were studied. The best results for enantiomeric excesses (ee) and conversion (c) were obtained with >99% and 58%, respectively, for the reaction time 48 h, initial substrate concentration 1 m

scholarly journals Purification and cDNA Cloning of NADPH-Dependent Aldoketoreductase, Involved in Asymmetric Reduction of Methyl 4-Bromo-3-Oxobutyrate, from Penicillium citrinum IFO4631

2005 ◽  
Vol 71 (2) ◽  
pp. 1101-1104 ◽  
Author(s):  
Hiroyuki Asako ◽  
Ryuhei Wakita ◽  
Kenji Matsumura ◽  
Masatoshi Shimizu ◽  
Jun Sakai ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cdna Cloning ◽  
Cdna Clone ◽  
Asymmetric Reduction ◽  
Optical Purity ◽  
Penicillium Citrinum ◽  
Regeneration System ◽  
Nadph Regeneration ◽  
High Optical Purity

ABSTRACT Penicillium citrinum was found to catalyze the reduction of methyl 4-bromo-3-oxobutyrate to methyl (S)-4-bromo-3-hydroxybutyrate [(S)-BHBM] with high optical purity. From the strain, a cDNA clone encoding a novel NADPH-dependent alkyl 4-halo-3-oxobutyrate reductase (KER) was isolated. Escherichia coli cells overexpressing KER produced (S)-BHBM in the presence of an NADPH-regeneration system.

scholarly journals The effect of systematic error on the accuracy of Michaelis constants and maximum velocities estimated by using the integrated Michaelis–Menten equation (Short Communication)

1974 ◽  
Vol 143 (3) ◽  
pp. 779-781 ◽  
Author(s):  
Peter F. J. Newman ◽  
Gordon L. Atkins ◽  
Ian A. Nimmo
Keyword(s):  
Reaction Time ◽  
Systematic Error ◽  
Substrate Concentration ◽  
Unknown Parameter ◽  
Short Communication ◽  
Systematic Errors ◽  
Product Concentration ◽  
Initial Substrate ◽  
Michaelis Constants ◽  
Initial Substrate Concentration

Systematic errors in initial substrate concentration (s0), product concentration and reaction time give much larger errors in the Michaelis–Menten parameters unless s0 is treated as an unknown parameter. These errors are difficult to detect because the fitted curve deviates little from the data. The effect of non-enzymic reaction is also examined.

scholarly journals Evaluating the Performance of Three Chambers Microbial Salinity Cell (MSC) Subjected to Different Substrate Concentrations to Accomplish Simultaneous Organic and Salt Removal in the Wastewater

2020 ◽  
Vol 11 (1) ◽  
pp. 19-26
Author(s):  
Rustiana Yuliasni ◽  
Nur Zen ◽  
Nanik Indah Setianingsih
Keyword(s):  
Substrate Concentration ◽  
Carbon Cloth ◽  
Anode Chamber ◽  
Initial Substrate ◽  
Conductivity Increase ◽  
Maximum Current ◽  
Maximum Conductivity ◽  
Vulcan Carbon ◽  
Substrate Concentrations ◽  
Initial Substrate Concentration

This study aimed to identify the effect of substrate concentration on the performance of A Three chambers Microbial Salinity Cell (a three chambers MSC). In this study, 3 three chambers MSC was made of plexy glass with total volume of 200 ml.  Alumunium wrapped with with platinum on vulcan carbon cloth were used as electrodes,with each working area 63 cm2. The results showed that a Three chambers Microbial Salinity Cell was able to generate electricity and at the same time removed salinity. The degree of electricity deneration and salinity removal were influenced by initial substrate concentration in the anode chamber. The higher substrate concentration, the better performance of MSC. The best performance of MSC achieved when COD was 2034 mg/L, resulted in maximum  voltage of 0. 44 V, and  maximum current density of 0.29 mA/m2. With % CE was 5.4%. The maximum conductivity increase in salinity chamber was  from 11.2 µS/cm  to 1027 µS/cm (salinity 0.57% ppt).

scholarly journals STUDI PENGARUH pH AWAL MEDIA DAN KONSENTRASI SUBSTRAT PADA PROSES FERMENTASI PRODUKSI BIOETANOL DARI HIDROLISAT TEPUNG BIJI KLUWIH (Actinocarpus communis) DENGAN MENGGUNAKAN Saccharomyces cerevisiae

2018 ◽  
Vol 6 (2) ◽  
pp. 115
Author(s):  
I Gede Yogi Wikrama Yuda ◽  
I Made Mahaputra Wijaya ◽  
Ni Putu Suwariani
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Substrate Concentration ◽  
Fermentation Process ◽  
Total Suspended Solid ◽  
Suspended Solid ◽  
Solid Substrate ◽  
Ethanol Content ◽  
Optimum Ph ◽  
Initial Ph ◽  
Descriptive Method

The aims of this study were to determine the optimum pH of media and substrate concentration on fermentation process that affected the production of bioetanol from kluwih (Actinocarpus communis) seed by Saccharomyces cerevisiae, and to obtain initial pH of media and substrate concentration on fermentation process that can a obtain the highest concentration of bioethanol. The research was designed by 2 factors. The first factor is initial pH of media that consist of three levels: 4, 4.5, and 5. The second factor is substrate concentration that consist of three levels: 2.5 %, 5 %, and 7.5 %. The data was obtained from series of tests and then it analyzed and produced presented by descriptive method. The results showed that the initial pH of media had an effect on ethanol content, and the pH, but not effected on total resulting suspended solid. Substrate concentration had an effect on ethanol content and total suspended solid. Interaction of both treatments had an effect on ethanol content from fermented flour of kluwih seed by used Saccharomyces cerevisiae. The best treatment to produce ethanol from fermented flour of  kluwih seed is by using the initial pH of media 4.5 and substrate concentration amount 7.5 % that yielded the highest ethanol content of 6.13 mL.                                                                                                                                           Key words:  Actinocarpus communis, ethanol, fermentation, the initial pH of media, substrate concentration

Influence of So/Xo Ratio on Anaerobic Activity Test

1999 ◽  
Vol 40 (8) ◽  
pp. 9-15 ◽  
Author(s):  
Gloria Moreno ◽  
Arturo Cruz ◽  
Germán Buitrón
Keyword(s):  
Substrate Concentration ◽  
Reaction Rate ◽  
Biomass Concentration ◽  
Sole Source ◽  
Yield Coefficient ◽  
Initial Biomass Concentration ◽  
Activity Test ◽  
Initial Substrate ◽  
Kinetic Coefficients ◽  
Initial Substrate Concentration

The effect of the substrate/microorganism ratio during the development of anaerobic activity test was studied. The experimentation was carried out in serum bottles at 35°C. Two sets of experiments utilizing acetate and an azo dye (blue disperse 79) as the sole source of carbon were studied. It was observed that mixing has an important influence on the results. The initial substrate concentration and the initial biomass concentration had a significant effect on the reaction rate and on the biomass yield coefficient, Yobs. Different kinetic coefficients were found for the case of equal So/Xo ratio, but different initial substrate concentration.

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