Bioproduction oftrans-Aconitic Acid from Citric Acid by Whole-Cell Reaction ofEscherichia coliHeterologously Expressing the Aconitate Isomerase Gene fromPseudomonassp. WU-0701

2016 ◽  
Vol 1 (7) ◽  
pp. 1467-1471 ◽  
Author(s):  
Keiichi Kobayashi ◽  
Junya Maruebi ◽  
Kohtaro Kirimura
Keyword(s):  
Citric Acid ◽  
Cell Reaction ◽  
Whole Cell ◽  
Aconitic Acid

Aconitic Acid from Citric Acid by Catalytic Dehydration

1945 ◽  
Vol 37 (10) ◽  
pp. 963-967 ◽  
Author(s):  
Robert R. Umbdenstock ◽  
Paul F. Bruins
Keyword(s):  
Citric Acid ◽  
Aconitic Acid

Application to Photocatalytic H2Production of a Whole-Cell Reaction by RecombinantEscherichia coliCells Expressing [FeFe]-Hydrogenase and Maturases Genes

2016 ◽  
Vol 128 (28) ◽  
pp. 8177-8180 ◽  
Author(s):  
Yuki Honda ◽  
Hidehisa Hagiwara ◽  
Shintaro Ida ◽  
Tatsumi Ishihara
Keyword(s):  
Cell Reaction ◽  
Whole Cell

scholarly journals P212A Mutant of Dihydrodaidzein Reductase Enhances (S)-Equol Production and Enantioselectivity in a Recombinant Escherichia coli Whole-Cell Reaction System

2016 ◽  
Vol 82 (7) ◽  
pp. 1992-2002 ◽  
Author(s):  
Pyung-Gang Lee ◽  
Joonwon Kim ◽  
Eun-Jung Kim ◽  
EunOk Jung ◽  
Bishnu Prasad Pandey ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Reaction System ◽  
Gut Bacteria ◽  
Site Directed Mutagenesis ◽  
Anaerobic Growth ◽  
Efficient Production ◽  
Cell Reaction ◽  
Whole Cell ◽  
Content Type ◽  
Postmenopausal Symptoms

ABSTRACT(S)-Equol, a gut bacterial isoflavone derivative, has drawn great attention because of its potent use for relieving female postmenopausal symptoms and preventing prostate cancer. Previous studies have reported on the dietary isoflavone metabolism of several human gut bacteria and the involved enzymes for conversion of daidzein to (S)-equol. However, the anaerobic growth conditions required by the gut bacteria and the low productivity and yield of (S)-equol limit its efficient production using only natural gut bacteria. In this study, the low (S)-equol biosynthesis of gut microorganisms was overcome by cloning the four enzymes involved in the biosynthesis fromSlackia isoflavoniconvertensintoEscherichia coliBL21(DE3). The reaction conditions were optimized for (S)-equol production from the recombinant strain, and this recombinant system enabled the efficient conversion of 200 μM and 1 mM daidzein to (S)-equol under aerobic conditions, achieving yields of 95% and 85%, respectively. Since the biosynthesis oftrans-tetrahydrodaidzein was found to be a rate-determining step for (S)-equol production, dihydrodaidzein reductase (DHDR) was subjected to rational site-directed mutagenesis. The introduction of the DHDR P212A mutation increased the (S)-equol productivity from 59.0 mg/liter/h to 69.8 mg/liter/h in the whole-cell reaction. The P212A mutation caused an increase in the (S)-dihydrodaidzein enantioselectivity by decreasing the overall activity of DHDR, resulting in undetectable activity for (R)-dihydrodaidzein, such that a combination of the DHDR P212A mutant with dihydrodaidzein racemase enabled the production of (3S,4R)-tetrahydrodaidzein with an enantioselectivity of >99%.

scholarly journals Investigation on Reaction Sequence and Group Site of Citric Acid with Cellulose Characterized by FTIR in Combination with Two-Dimensional Correlation Spectroscopy

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2071 ◽  
Author(s):  
Zijing Cai ◽  
Bolin Ji ◽  
Kelu Yan ◽  
Quan Zhu
Keyword(s):  
Citric Acid ◽  
Unsaturated Acid ◽  
Cotton Fabrics ◽  
Acid Anhydride ◽  
Correlation Spectroscopy ◽  
Two Dimensional ◽  
Practical Application ◽  
Reaction Sequence ◽  
Aconitic Acid ◽  
Different Temperatures

Cotton fabrics are prone to wrinkles and can be treated with citric acid (CA) to obtain good anti-wrinkle properties. However, the yellowing of the CA-treated fabrics is one big obstacle to the practical application of citric acid. The changing sequence order of CA anhydride and unsaturated acid (the reason for yellowing), such as aconitic acid (AA), has not been investigated. Herein, Fourier transform infrared (FTIR) spectroscopy, two-dimensional correlation spectroscopy (2Dcos), and Gaussian calculation were employed to characterize the reaction mechanism between CA with cellulose. FTIR spectra of the CA-treated fabrics heated under different temperatures were collected and further analyzed with 2Dcos. The results indicated the changing sequence order: 1656 cm−1→1784 cm−1→1701 cm−1, (“→” means earlier than), i.e., unsaturated acid→anhydride→ester. Moreover, a change of Gibbs free energy (ΔG) showed that trans-AA (ΔG = −22.10 kJ/mol) is more thermodynamically favorable to be formed than CA anhydride 1 (ΔG = −0.90 kJ/mol), which was proved by Gaussian computational modeling. By taking cellobiose as a model of cellulose, the ΔG results proved that O(6)–H(6) on the glucose ring is the most likely hydroxyl to react with anhydride originated from CA or AA, especially with the terminal carbonyl group.

scholarly journals Integration of whole-cell reaction and product isolation: Highly hydrophobic solvents promote in situ substrate supply and simplify extractive product isolation

2017 ◽  
Vol 257 ◽  
pp. 110-117 ◽  
Author(s):  
Dorothea Leis ◽  
Bernhard Lauß ◽  
Robert Macher-Ambrosch ◽  
Andreas Pfennig ◽  
Bernd Nidetzky ◽  
...  
Keyword(s):  
Cell Reaction ◽  
Whole Cell ◽  
Substrate Supply ◽  
Highly Hydrophobic

Determination of Aconitic Acid in Mixtures with Citric Acid

1947 ◽  
Vol 19 (11) ◽  
pp. 879-880 ◽  
Author(s):  
J. A. Ambler ◽  
E. J. Roberts
Keyword(s):  
Citric Acid ◽  
Aconitic Acid
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