scholarly journals Promising Pathway of Thermostable Mannitol Dehydrogenase (MtDH) from Caldicellulosiruptor hydrothermalis 108 for D-Mannitol Synthesis

Separations ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 76
Author(s):  
Marwa Y. F. Koko ◽  
Rokayya Sami ◽  
Bertrand Muhoza ◽  
Ebtihal Khojah ◽  
Ahmed M. A. Mansour
Keyword(s):  
Escherichia Coli ◽  
Formate Dehydrogenase ◽  
Enzyme System ◽  
Catalytic Efficiency ◽  
Optimum Temperature ◽  
Initial Activity ◽  
Mannitol Dehydrogenase ◽  
Whole Cells ◽  
Optimum Ph ◽  
Molecular Masses

In this study, we conducted the characterization and purification of the thermostable mannitol dehydrogenase (MtDH) from Caldicellulosiruptor hydrothermalis 108. Furthermore, a coupling-enzyme system was designed using (MtDH) from Caldicellulosiruptor hydrothermalis 108 and formate dehydrogenase (FDH) from Ogataea parapolymorpha. The biotransformation system was constructed using Escherichia coli whole cells. The purified enzyme native and subunit molecular masses were 76.7 and 38 kDa, respectively, demonstrating that the enzyme was a dimer. The purified and couple enzyme system results were as follows; the optimum pH for the reduction and the oxidation was 7.0 and 8.0, the optimum temperature was 60 °C, the enzyme activity was inhibited by EDTA and restored by zinc. Additionally, no activity was detected with NADPH and NADP. The purified enzyme showed high catalytic efficiency Kcat 385 s−1, Km 31.8 mM, and kcat/Km 12.1 mM−1 s−1 for D-fructose reduction. Moreover, the purified enzyme retained 80%, 75%, 60%, and 10% of its initial activity after 4 h at 55, 60, 65, and 75 °C, respectively. D-mannitol yield was achieved via HPLC. Escherichia coli are the efficient biotransformation mediator to produce D-mannitol (byproducts free) at high temperature and staple pH, resulting in a significant D-mannitol conversation (41 mg/mL) from 5% D-fructose.

scholarly journals Biosynthesis of Putrescine from L-arginine Using Engineered Escherichia coli Whole Cells

Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 947
Author(s):  
Hongjie Hui ◽  
Yajun Bai ◽  
Tai-Ping Fan ◽  
Xiaohui Zheng ◽  
Yujie Cai
Keyword(s):  
Escherichia Coli ◽  
Biogenic Amine ◽  
Arginine Decarboxylase ◽  
Optimal Concentration ◽  
Optimum Temperature ◽  
Whole Cell ◽  
Whole Cells ◽  
Copy Numbers ◽  
Optimum Ph ◽  
Engineered Escherichia Coli

Putrescine, a biogenic amine, is a highly valued compound in medicine, industry, and agriculture. In this study, we report a whole-cell biocatalytic method in Escherichia coli for the production of putrescine, using L-arginine as the substrate. L-arginine decarboxylase and agmatine ureohydrolase were co-expressed to produce putrescine from L-arginine. Ten plasmids with different copy numbers and ordering of genes were constructed to balance the expression of the two enzymes, and the best strain was pACYCDuet-speB-speA. The optimal concentration of L-arginine was determined to be 20 mM for this strain. The optimum pH of the biotransformation was 9.5, and the optimum temperature was 45 °C; under these conditions, the yield of putrescine was 98%. This whole-cell biocatalytic method appeared to have great potential for the production of putrescine.

scholarly journals Hydrolysis of penicillins and related compounds by the cell-bound penicillin acylase of Escherichia coli

1969 ◽  
Vol 115 (4) ◽  
pp. 733-739 ◽  
Author(s):  
M. Cole
Keyword(s):  
Escherichia Coli ◽  
Penicillin Acylase ◽  
Side Chain ◽  
Bacterial Cells ◽  
Optimum Temperature ◽  
Phenoxymethyl Penicillin ◽  
Optimum Ph ◽  
Penicillanic Acid ◽  
Hydrolysis Of ◽  
Related Compounds

1. A method is given for the preparation of penicillin acylase by using Escherichia coli N.C.I.B. 8743 and a strain selected for higher yield. The enzyme is associated with the bacterial cells and removes the side chains of penicillins to give 6-amino-penicillanic acid and a carboxylic acid. 2. The rates of penicillin deacylation indicated that p-hydroxybenzylpenicillin was the best substrate, followed in diminishing order by benzyl-, dl-α-hydroxybenzyl-, 2-furylmethyl-, 2-thienylmethyl-, d-α-aminobenzyl-, n-propoxymethyl- and isobutoxymethyl-penicillin. Phenylpenicillin and dl-α-carboxybenzylpenicillin were not substrates and phenoxymethyl-penicillin was very poor. 3. Amides and esters of the above penicillins were also substrates for the deacylation reaction, as were cephalosporins with a thienylmethyl side chain. 4. For the deacylation of 2-furylmethylpenicillin at 21° the optimum pH was 8·2. The optimum temperature was 60° at pH7. 5. By using selection A of N.C.I.B. 8743 and determining reaction velocities by assaying yields of 6-amino-penicillanic acid in a 10min. reaction at 50° and pH8·2, the Km for benzylpenicillin was found to be about 30mm and the Km for 2-furylmethylpenicillin, about 10mm. The Vmax. values were 0·6 and 0·24μmole/min./mg. of bacterial cells respectively.

Properties of poly(ADP-ribose) synthetase from rat pancreas and poly(ADP-ribosylation) of basic nuclear proteins

1978 ◽  
Vol 56 (8) ◽  
pp. 784-790 ◽  
Author(s):  
G. G. Poirier ◽  
P. Savard ◽  
D. Rajotte ◽  
J. Morisset ◽  
A. Lord
Keyword(s):  
Nuclear Protein ◽  
Enzyme System ◽  
Histone H1 ◽  
Average Chain Length ◽  
Optimum Temperature ◽  
Isolated Nuclei ◽  
Rat Pancreas ◽  
Optimum Ph ◽  
Insoluble Product ◽  
Substrate Concentrations

The isolated nuclei of rat pancreas contain an enzyme system that will incorporate 3H-labeled NAD into an acid-insoluble product, which is shown to be poly(ADP-ribose). The enzyme has an optimum pH of 7.8 and the optimum temperature is between 20 and 30 °C. Optimum Mg2+ concentration is 8 mM and dithiothreitol also stimulates the enzyme at a concentration of 8 mM. Under standard conditions, the Km value for the reaction is 0.25 mM and an inhibition by the substrate is observed at high substrate concentrations. It has also been found that only one basic nuclear protein, that is, histone H1, is modified by the synthetase. An average chain length of 5.0 is found in the nuclei and of 4.5 on histone H1. Radioautographic studies show that poly(ADP-ribose) is closely associated with chromatin.

scholarly journals Encapsulation of HRP Enzyme onto a Magnetic Fe3O4 Np–PMMA Film via Casting with Sustainable Biocatalytic Activity

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 181 ◽  
Author(s):  
Wesam H. Abdulaal ◽  
Yaaser Q. Almulaiky ◽  
Reda M. El-Shishtawy
Keyword(s):  
Metal Ions ◽  
Immobilized Enzyme ◽  
Pmma Film ◽  
Optimum Temperature ◽  
Initial Activity ◽  
Casting Method ◽  
Ph Optimum ◽  
Optimum Ph ◽  
Triton X ◽  
Enzyme Changes

Horseradish peroxidase (HRP) enzyme was effectively encapsulated onto an Fe3O4 nanoparticle–polymethyl methacrylate (PMMA) film via the casting method. The HRP was immobilized on the 0.5% Fe3O4Np–PMMA film and characterized by Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Moreover, the reusability, thermal stability, optimum pH, optimum temperature, the influence of metal ions, and the effects of detergent and organic solvent were investigated. After optimizing the immobilization conditions, the highest efficiency of the immobilized enzyme was 88.4% using 0.5% Fe3O4Np–PMMA. The reusability of the immobilized HRP activity was 78.5% of its initial activity after being repeatedly used for 10 cycles. When comparing the free and immobilized forms of the HRP enzyme, changes in the optimum temperature and optimum pH from 30 to 40 °C and 7.0 to 7.5, respectively, were observed. The Km and Vmax for the immobilized HRP were estimated to be 41 mM, 0.89 U/mL for guaiacol and 5.84 mM, 0.66 U/mL for H2O2, respectively. The high stability of the immobilized HRP enzyme was obtained using metal ions, a high urea concentration, isopropanol, and Triton X-100. In conclusion, the applicability of immobilized HRP involves the removal of phenol in the presence of hydrogen peroxide, therefore, it could be a potential catalyst for the removal of wastewater aromatic pollutants.

scholarly journals Purification, crystallization and characterization of N-acetylneuraminate lyase from Escherichia coli

1991 ◽  
Vol 276 (2) ◽  
pp. 541-546 ◽  
Author(s):  
K Aisaka ◽  
A Igarashi ◽  
K Yamaguchi ◽  
T Uwajima
Keyword(s):  
Escherichia Coli ◽  
Gel Filtration ◽  
Genetically Engineered ◽  
E Coli ◽  
Sds Page ◽  
Optimum Ph ◽  
Molecular Masses ◽  
Related Compounds ◽  
Optimum Ph And Temperature

N-Acetylneuraminate lyase produced by Escherichia coli was purified and crystallized from a genetically engineered strain (E. coli SF8/pNAL1). The enzyme showed apparent molecular masses of 105,000 Da on gel filtration and 35,000 Da on SDS/PAGE, suggesting that the enzyme is a trimer. The apparent optimum pH and temperature were found to be 6.5-7.0 and 80 degrees C respectively. The Km values for N-acetylneuraminate and N-glycollylneuraminate were 3.3 and 3.3 mM respectively. The enzyme was inhibited by reduction with NaBH4 in the presence of the substrate, indicating that the enzyme belongs to the Schiff-base-forming Class I aldolases. The enzyme was strongly inhibited by Cu2+ ions, p-chloromercuribenzoate and N-bromosuccinimide, and also inhibited competitively by the reaction product, pyruvate, and its structurally related compounds, dihydroxyacetone and DL-glyceraldehyde.

scholarly journals Pengaruh pH dan Suhu terhadap Produksi Antibiotika dari Isolat Bakteri Endofitik pada Tumbuhan Andalas (Morus macroura Miq.)

2019 ◽  
Vol 6 (1) ◽  
pp. 90
Author(s):  
Riski Budi Yani ◽  
Anthoni Agustien ◽  
Feskaharny Alamsjah
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Survey Method ◽  
Bacillus Sp ◽  
Optimum Temperature ◽  
Paper Disk ◽  
Optimum Ph ◽  
Disk Method ◽  
And Staphylococcus Aureus ◽  
Selection Of

The study used survey method and the data were analysed descriptively. The selection of the bacteria which produce antibiotic had been with paper disk method and used Escherichia coli and Staphylococcus aureus as the sample bacteria. This result showed pH 7,0 was succesful optimum pH antibiotic produced for Bacillus sp.1 and Bacillus sp.2. and 370C was the optimum temperature to antibiotic produced from Bacillus sp.1 and Bacillus sp.2.

Efficient biosynthesis of enantiopure tolvaptan by utilizing alcohol dehydrogenase-catalyzed enantioselective reduction

2018 ◽  
Vol 20 (6) ◽  
pp. 1224-1227 ◽  
Author(s):  
Hong-Lei Zhang ◽  
Chao Zhang ◽  
Meng-Nan Han ◽  
Chao-Hong Pei ◽  
Zhi-Dong Xu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Alcohol Dehydrogenase ◽  
Soybean Oil ◽  
Efficient Method ◽  
Formate Dehydrogenase ◽  
Whole Cells ◽  
Enantioselective Reduction

Using whole cells of Escherichia coli co-expressing alcohol dehydrogenase (PsADH) and formate dehydrogenase (CpFDH) in a biphasic aqueous–soybean oil system is shown to be an efficient method for the biosynthesis of enantiopure tolvaptan.

scholarly journals Molecular Cloning and Characterization of Fengycin Synthetase Gene fenB from Bacillus subtilis

1998 ◽  
Vol 180 (5) ◽  
pp. 1338-1341 ◽  
Author(s):  
Guang-Huey Lin ◽  
Chyi-Liang Chen ◽  
Johannes Scheng-Ming Tschen ◽  
San-San Tsay ◽  
Yu-Sun Chang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Bacillus Subtilis ◽  
Amino Acid ◽  
Substrate Specificity ◽  
Affinity Chromatography ◽  
Molecular Mass ◽  
Optimum Temperature ◽  
Turnover Number ◽  
Optimum Ph

ABSTRACT A fengycin synthetase gene, fenB, has been cloned and sequenced. The protein (FenB) encoded by this gene has a predicted molecular mass of 143.6 kDa. This protein was overexpressed inEscherichia coli and was purified to near homogeneity by affinity chromatography. Experimental results indicated that the recombinant FenB has a substrate specificity toward isoleucine with an optimum temperature of 25°C, an optimum pH of 4.5, aKm value of 922 μM, and a turnover number of 236 s−1. FenB also consists of a thioesterase domain, suggesting that this protein may be involved in the activation of the last amino acid of fengycin.

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