One‐Step Synthesis of W 2 C@N,P‐C Nanocatalysts for Efficient Hydrogen Electrooxidation across the Whole pH Range

2019 ◽  
Vol 29 (31) ◽  
pp. 1902505 ◽  
Author(s):  
Bingyan Xiong ◽  
Wenbin Zhao ◽  
Lisong Chen ◽  
Jianlin Shi
Keyword(s):  
One Step ◽  
Hydrogen Electrooxidation ◽  
Ph Range

scholarly journals TEMPO-Functionalized Nanoporous Au Nanocomposite for the Electrochemical Detection of H2O2

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Dongxiao Wen ◽  
Qianrui Liu ◽  
Ying Cui ◽  
Huaixia Yang ◽  
Jinming Kong
Keyword(s):  
Electrochemical Detection ◽  
Nanoporous Gold ◽  
Carboxyl Groups ◽  
Time Interval ◽  
Optimal Conditions ◽  
Sem Images ◽  
One Step ◽  
Ph Range ◽  
Synthesis Approach ◽  
Higher Sensitivity

A novel nanocomposite of nanoporous gold nanoparticles (np-AuNPs) functionalized with 2,2,6,6-tetramethyl-1-piperidinyloxy radical (TEMPO) was prepared; assembled carboxyl groups on gold nanoporous nanoparticles surface were combined with TEMPO by the “bridge” of carboxylate-zirconium-carboxylate chemistry. SEM images and UV-Vis spectroscopies of np-AuNPs indicated that a safe, sustainable, and simplified one-step dealloying synthesis approach is successful. The TEMPO-np-AuNPs exhibited a good performance for the electrochemical detection of H2O2 due to its higher number of electrochemical activity sites and surface area of 7.49 m2g-1 for load bigger amount of TEMPO radicals. The TEMPO-functionalized np-AuNPs have a broad pH range and shorter response time for H2O2 catalysis verified by the response of amperometric signal under different pH and time interval. A wide linear range with a detection limit of 7.8 × 10-7 M and a higher sensitivity of 110.403 μA mM-1cm-2 were obtained for detecting H2O2 at optimal conditions.

scholarly journals A Novel Dimeric Exoglucanase (GH5_38): Biochemical and Structural Characterisation towards its Application in Alkyl Cellobioside Synthesis

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 746 ◽  
Author(s):  
Mpho S. Mafa ◽  
Heinrich W. Dirr ◽  
Samkelo Malgas ◽  
Rui W. M. Krause ◽  
Konanani Rashamuse ◽  
...  
Keyword(s):  
Glycoside Hydrolase ◽  
Kinetic Studies ◽  
Glycoside Hydrolase Family ◽  
Primary Alcohols ◽  
Structural Characterisation ◽  
Alkyl Glycosides ◽  
Glycoside Synthesis ◽  
One Step ◽  
Ph Range ◽  
The One

An exoglucanase (Exg-D) from the glycoside hydrolase family 5 subfamily 38 (GH5_38) was heterologously expressed and structurally and biochemically characterised at a molecular level for its application in alkyl glycoside synthesis. The purified Exg-D existed in both dimeric and monomeric forms in solution, which showed highest activity on mixed-linked β-glucan (88.0 and 86.7 U/mg protein, respectively) and lichenin (24.5 and 23.7 U/mg protein, respectively). They displayed a broad optimum pH range from 5.5 to 7 and a temperature optimum from 40 to 60 °C. Kinetic studies demonstrated that Exg-D had a higher affinity towards β-glucan, with a Km of 7.9 mg/mL and a kcat of 117.2 s−1, compared to lichenin which had a Km of 21.5 mg/mL and a kcat of 70.0 s−1. The circular dichroism profile of Exg-D showed that its secondary structure consisted of 11% α-helices, 36% β-strands and 53% coils. Exg-D performed transglycosylation using p-nitrophenyl cellobioside as a glycosyl donor and several primary alcohols as acceptors to produce methyl-, ethyl- and propyl-cellobiosides. These products were identified and quantified via thin-layer chromatography (TLC) and liquid chromatography–mass spectrometry (LC-MS). We concluded that Exg-D is a novel and promising oligomeric glycoside hydrolase for the one-step synthesis of alkyl glycosides with more than one monosaccharide unit.

scholarly journals Degradation of methylene blue with magnetic Co-doped Fe3O4@FeOOH nanocomposites as heterogeneous catalysts of peroxymonosulfate

RSC Advances ◽  
2019 ◽  
Vol 9 (31) ◽  
pp. 17664-17673 ◽  
Author(s):  
Kai Wang ◽  
Yi Yang ◽  
Tian C. Zhang ◽  
Ying Liang ◽  
Qingguo Wang
Keyword(s):  
Methylene Blue ◽  
Hydrothermal Synthesis ◽  
Heterogeneous Catalysts ◽  
Synthesis Process ◽  
Wide Ph Range ◽  
One Step ◽  
Ph Range ◽  
Co Doped

Magnetic Co-doped Fe3O4@FeOOH nanocomposites were prepared in one step using the hydrothermal synthesis process for catalyzing peroxymonosulfate (PMS) to degrade refractory methylene blue (MB) at a wide pH range (3.0–10.0).

Expression, Enzymatic Characterization, and High-Level Production of Glucose Isomerase from Actinoplanes missouriensis CICIM B0118(A) in Escherichia coli

2011 ◽  
Vol 66 (11-12) ◽  
pp. 605-613 ◽  
Author(s):  
He Wang ◽  
Ruijin Yang ◽  
Xiao Hua ◽  
Zhong Zhang ◽  
Wei Zhao ◽  
...  
Keyword(s):  
Ph Value ◽  
Glucose Isomerase ◽  
Medium Composition ◽  
Gene Encoding ◽  
E Coli ◽  
Optimum Ph ◽  
One Step ◽  
Ph Range ◽  
High Level ◽  
Level Production

High-level production of recombinant glucose isomerase (rGI) is desirable for lactulose synthesis. In this study, the xylA gene encoding glucose isomerase from Actinoplanes missouriensis CICIM B0118(A) was cloned and expressed in E. coli BL21(DE3), and high-level production was performed by optimization of the medium composition. rGI was purified from a recombinant E. coli BL21(DE3) and characterized. The optimum pH value of the purified enzyme was 8.0 and it was relatively stable within the pH range of 7.0 - 9.0. Its optimum temperature was around 85 °C, and it exhibited good thermostability when the temperature was lower than 90 °C. The maximum enzyme activity required the presence of both Co2+ and Mg2+, at the concentrations of 200 μM and 8 mM, respectively. With high-level expression and the simple one-step chromatographic purification of the His-tagged recombinant enzyme, this GI could be used in industrial production of lactulose as a potential economic tool

One‐step Synthesis of Self‐standing Ni 3 S 2 /Ni 2 P Heteronanorods on Nickel Foam for Efficient Electrocatalytic Hydrogen Evolution over a Wide pH Range

ChemCatChem ◽  
2018 ◽  
Vol 10 (23) ◽  
pp. 5487-5495 ◽  
Author(s):  
Yun Zhou ◽  
Tongtong Li ◽  
Shengqi Xi ◽  
Cheng He ◽  
Xigang Yang ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Nickel Foam ◽  
Wide Ph Range ◽  
One Step ◽  
Ph Range

Overproduction and characterization of xylanase B fromAspergillus niger

2005 ◽  
Vol 51 (2) ◽  
pp. 177-183 ◽  
Author(s):  
Anthony Levasseur ◽  
Marcel Asther ◽  
Eric Record
Keyword(s):  
Expression System ◽  
Gene Promoter ◽  
Recombinant Enzyme ◽  
Glycoside Hydrolase Family ◽  
Metal Affinity ◽  
Homologous Expression ◽  
Dehydrogenase Gene ◽  
Beet Pulp ◽  
One Step ◽  
Ph Range

The xynB gene, which encodes endo-β-1,4-xylanase XynB, in Aspergillus niger BRFM281 was amplified by RT-PCR using mRNA isolated from a culture containing sugar beet pulp as an inducer. The cDNA was cloned into an expression cassette under the control of the strong and constitutive glyceraldhehyde-3-phosphate dehydrogenase gene promoter. The expression system was designed to produce the recombinant enzyme XynB with a six-histidine peptide fused to the carboxy end of the protein. Homologous overproduction of XynB was successfully achieved in shake flask cultures, and the secretion yield was estimated to be 900 mg·L–1. The recombinant XynB was purified 1.5-fold by immobilized metal affinity chromatography to homogeneity using a one-step purification protocol with 71% recovery. The purified recombinant enzyme was fully characterized and has a molecular mass of 23 kDa and an optimal activity at pH 5.5 and 50 °C with stability in the pH range 4.0-7.0 and temperature up to 50 °C. Using soluble oat spelts xylan, the determined Kmand Vmaxvalues were 7.1 mg·mL–1and 3881 U·mg–1, respectively.Key words: homologous expression, glycoside hydrolase family 11, cell-wall degradation.

scholarly journals Purification and characterisation of a phosphatidylcholine-binding protein from duck Biceps femoris muscle

2014 ◽  
Vol 54 (2) ◽  
pp. 194 ◽  
Author(s):  
D. Y. Wang ◽  
M. H. Zhang ◽  
F. Liu ◽  
Y. Z. Zhu ◽  
W. M. Xu
Keyword(s):  
Binding Capacity ◽  
Binding Protein ◽  
Biceps Femoris ◽  
Inhibitory Effect ◽  
Exchange Chromatography ◽  
Biceps Femoris Muscle ◽  
One Step ◽  
Widespread Phenomenon ◽  
Ph Range ◽  
Femoris Muscle

The interaction between protein and phospholipids is a widespread phenomenon involving several physiological events in postmortem muscle. We hereby report a method for one-step purification of a phosphatidylcholine-binding (PC-binding) protein from duck Biceps femoris muscle with relatively high purity and yield using ion-exchange chromatography. This PC-binding protein has an inhibitory effect on the activity of phospholipase A2 (PLA2). A decrease (~62.3%) in PLA2 activity was observed. It had a strong affinity to bind PC at pH range of 6.2–6.8 with a peak at pH 6.6 (13.36 ± 0.48 g PC/g protein); in addition, raising ATP content from 1 to 5 μmol/mL enhanced the binding capacity. The PC-binding protein plays a potential role in the integrity of membrane and meat quality.

scholarly journals Biological Characteristics and Genomic Analysis of Aeromonas Hydrophila Phage BUCT551 Isolated From Aquatic Sewage

2021 ◽  
Author(s):  
Hongbo Qin ◽  
Shiting He ◽  
Xuling Xu ◽  
Xiaoping An ◽  
Ke Liu ◽  
...  
Keyword(s):  
Aeromonas Hydrophila ◽  
Burst Size ◽  
Genomic Analysis ◽  
Opportunistic Pathogen ◽  
Range Analysis ◽  
Transmission Electron ◽  
Blastn Analysis ◽  
One Step ◽  
Ph Range ◽  
The One

Abstract Aeromonas hydrophila is a common opportunistic pathogen in aquaculture and is ubiquitous in aquatic environment. Whereby its accessibility, variety and host specificity, phage is increasingly considered as a promising complementary medicine for antibiotics. However, a small amount of A. hydrophila phages have been characterized, which suggests the significance to isolate and characterize novel A. hydrophila phages. In this study, we isolated a novel Aeromonas hydrophila phage using A. hydrophila strain A18 as an indicator and designated it as BUCT551, and it was identified as Myoviridae phage by transmission electron microscopy (TEM). The whole genome sequencing of the phage BUCT551 revealed that it has a linear DNA genome of 613,82 bp. BLASTn analysis showed that phage BUCT551 shared 86.75% homology with A. hydrophila phage LAh_7 (Genebank ID: MK838113.1). The one-step growth curve demonstrated that phage BUCT551 had a latent period of 20 min and the burst size of 32 pfu/cell at its optimal MOI of 0.1. The phage BUCT551 had a survival pH range from 5 to 10 and tolerant temperature from 0℃ to 40℃. Host range analysis shown that the phage was able to lyse not only A. hydrophila, but also A. veronii.

scholarly journals A Laser Reduced Graphene Oxide Grid Electrode for the Voltammetric Determination of Carbaryl

2021 ◽  
Author(s):  
Muhammad Saqib ◽  
Elena V. Dorozhko ◽  
Jiri Barek ◽  
Vlastimil Vyskocil ◽  
Elena Korotkova ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Fruit Juices ◽  
Grid Electrode ◽  
Oxidation Current ◽  
Reduced Graphene ◽  
Electrochemically Active ◽  
One Step ◽  
Ph Range

Laser reduced graphene oxide (LRGO) on a PET substrate was prepared in one-step to obtain the LRGO grid electrode for sensitive carbaryl determination. The grid form results in a grid distribution of different electrochemically active zones affecting the electroactive substance diffusion towards to the electrode surface and increasing the electrochemical sensitivity for carbaryl determination. Carbaryl is electrochemically irreversibly oxidized by the secondary amine moiety of the molecule with the loss of one proton and one electron in the pH range from 5 to 7 by LSV on the LRGO grid electrode with a scan rate of 300 mV/s. Some interference of the juice matrix molecules did not significantly affect the LSV oxidation current of carbaryl on the LRGO grid electrode after adsorptive accumulation without applied potential. The LRGO grid electrode can be used for LSV determination of carbaryl in fruit juices in the concentration range from 0.25 to 128 mg/L with LOD of 0.1 mg/L by. The fabrication of the LRGO grid electrode opens up possibilities for further inexpensive monitoring of carbaryl in other fruit juices and fruits.

Rational design of porous binary Pt-based nanodendrites as efficient catalysts for direct glucose fuel cells over a wide pH range

2017 ◽  
Vol 7 (13) ◽  
pp. 2819-2827 ◽  
Author(s):  
Kamel Eid ◽  
Yahia H. Ahmad ◽  
Siham Y. AlQaradawi ◽  
Nageh K. Allam
Keyword(s):  
Catalytic Activity ◽  
Oxidation Reaction ◽  
Rational Design ◽  
Glucose Oxidation ◽  
Room Temperature ◽  
Ph Values ◽  
Wide Ph Range ◽  
One Step ◽  
Ph Range ◽  
Glucose Oxidation Reaction

Porous binary PtPd, AuPt, PtCu, and PtNi nanodendrites prepared by a facile one-step reduction under ultrasonic irradiation at room temperature, exhibited a substantial catalytic activity towards glucose oxidation reaction at different pH values relative to a commercial Pt/C catalyst.

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