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.

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 The reliability of Michaelis constants and maximum velocities estimated by using the integrated Michaelis–Menten equation

1973 ◽  
Vol 135 (4) ◽  
pp. 779-784 ◽  
Author(s):  
Gordon L. Atkins ◽  
Ian A. Nimmo
Keyword(s):  
Substrate Concentration ◽  
Linear Method ◽  
Unknown Origin ◽  
Parameter Estimates ◽  
Initial Substrate ◽  
Non Linear ◽  
Michaelis Constants ◽  
Initial Substrate Concentration

1. Experimental progress curves were simulated for a reaction obeying Michaelis–Menten kinetics. 2. Km and V were estimated (a) by fitting the integrated Michaelis–Menten equation to the progress curves, and (b) from the initial slopes of the curves (i.e. from initial velocities). 3. The integrated equation could not be fitted successfully by a non-linear method, so it was transformed and fitted by a linear method. 4. Provided that the initial substrate concentration was greater than Km and the data were precise enough, the integrated equation gave parameter estimates which were unbiased and as reliable as those derived from initial velocities although based on fewer experiments. 5. The integrated equation could be used for progress curves of unknown origin.

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).

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.

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.

Sign in / Sign up

Export Citation Format

Share Document