scholarly journals New Reusable Solid Biosensor with Covalent Immobilization of the Horseradish Peroxidase Enzyme: In Situ Liberation Studies of Hydrogen Peroxide by Portable Chemiluminescent Determination

ACS Omega ◽  
2020 ◽  
Vol 5 (5) ◽  
pp. 2419-2427
Author(s):  
Sara Bocanegra-Rodríguez ◽  
Neus Jornet-Martínez ◽  
Carmen Molins-Legua ◽  
Pilar Campíns-Falcó
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Covalent Immobilization ◽  
Peroxidase Enzyme

Enzyme catalyzed polymerization and precipitation of aromatic compounds from aqueous solution

1993 ◽  
Vol 20 (5) ◽  
pp. 725-735 ◽  
Author(s):  
J. A. Nicell ◽  
J. K. Bewtra ◽  
N. Biswas ◽  
C. C. St. Pierre ◽  
K. E. Taylor
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Aromatic Compounds ◽  
Thermal Inactivation ◽  
Catalytic Efficiency ◽  
Reaction Products ◽  
Aromatic Substrate ◽  
Aromatic Substrates ◽  
Minimum Residual ◽  
Peroxidase Enzyme

Horseradish peroxidase enzyme (HRP), once activated by hydrogen peroxide, initiates the oxidation of a wide variety of aromatic compounds. Reaction products undergo a non-enzymatic polymerization to form water insoluble aggregates which are readily separated from solution. HRP was selected for application in wastewater treatment systems due to its stability and retention of its catalytic ability over wide ranges of pH and temperature. HRP activity was optimal between pH 5.7 and 8.5 with peak activity occurring at neutral pH. Activity increased with temperature up to 50 °C and declined at higher temperatures due to thermal inactivation. HRP was inactivated rapidly by hydrogen peroxide in the absence of an aromatic substrate. The efficiency of removal that was achieved was dependent on the nature of the aromatic undergoing treatment and the amount of enzyme provided due to the finite lifetime of the catalyst. Optimization of pH significantly improved catalytic efficiency with a corresponding savings in treatment costs. Optimal catalytic lifetime of HRP was achieved in the pH range of 7 to 9 for the eight phenolic compounds treated. The minimum residual level to which aromatic substrates were removed from solution was independent of the starting concentration of the aromatic substrate. Enhanced removal of hard-to-remove compounds was noted when mixtures of aromatic substrates were treated. Key words: horseradish peroxidase enzyme, polymerization, wastewater, phenols, aromatics amines.

scholarly journals Inhibitory effect of retinol acetate on horseradish peroxidase

2013 ◽  
Vol 67 (3) ◽  
pp. 419-426
Author(s):  
Vladan Djuric ◽  
Nebojsa Deletic ◽  
Vesna Stankov-Jovanovic ◽  
Ranko Simonovic
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Enzymatic Reaction ◽  
Inhibitory Effect ◽  
Enzyme Concentration ◽  
Water Soluble ◽  
Primary Role ◽  
Retinol Acetate ◽  
Peroxidase Enzyme

Primary role of peroxidase enzyme is to decompose endogenous hydrogen peroxide, when oxygen radical is being replaced by a less potent radical, which is its cosubstrates oxidized form. During this study, catalytic activity of horseradish peroxidase has been observed in the presence of antioxidants from vitamin group, such as C, E and A, i.e. their water-soluble forms. It was found that vitamin E showed no effect on the enzyme activity and fate of cosubstrate radicals from the group of benzidine derivatives. Vitamin C proceeds enzymatic reaction showing its antioxidative character, and absorbs electrons from radicals, bringing cosubstrate back to its relaxed state. On the other hand, vitamin A plays a role of uncompetitive peroxidase inhibitor, which is visible through decreasing initial rate of catalytic reaction, and is reflected as virtual decrease of enzyme concentration. Furthermore, it prolongs life of endogenous hydrogen peroxide, which could potentially lead to oxidative stress of cells. This inhibitory effect can be used in analytical purpose, for determination of retinol acetate content in a sample.

Continuous enzymatic treatment of 4-bromophenol initiated by UV irradiation

2010 ◽  
Vol 62 (9) ◽  
pp. 2016-2020 ◽  
Author(s):  
A. Meizler ◽  
F. A. Roddick ◽  
N. A. Porter
Keyword(s):  
Hydrogen Peroxide ◽  
Titanium Dioxide ◽  
Horseradish Peroxidase ◽  
Uv Irradiation ◽  
Active Sites ◽  
The Novel ◽  
Production Of Hydrogen ◽  
Phenolic Substances ◽  
In Situ Production

Horseradish peroxidase (HRP) can be used for the treatment of halogenated phenolic substances. In the presence of hydrogen peroxide phenols are oxidized to form polymers which undergo partial dehalogenation. However, when immobilized, the peroxidase is subject to inactivation due to blockage of the active sites by the growing polymers and to deactivation by elevated levels of hydrogen peroxide. When HRP immobilized on a novel glass-based support incorporating titanium dioxide is subjected to UV irradiation, hydrogen peroxide is produced and the nascent polymer is removed. In this work a reactor was constructed that utilized HRP immobilized on the novel support and the in situ production of hydrogen peroxide to treat 4-bromophenol as a model substrate. The system was operated for almost 17 hours with no apparent decline in activity.

scholarly journals Decolorization of Anthraquinonic Dyes from Textile Effluent Using Horseradish Peroxidase: Optimization and Kinetic Study

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Nataša Ž. Šekuljica ◽  
Nevena Ž. Prlainović ◽  
Andrea B. Stefanović ◽  
Milena G. Žuža ◽  
Dragana Z. Čičkarić ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Treatment Time ◽  
Substrate Inhibition ◽  
Oxygen Demand ◽  
Enzyme Concentration ◽  
Influence Of Process Parameters ◽  
Peroxidase Enzyme ◽  
Acid Blue ◽  
Acid Violet

Two anthraquinonic dyes, C.I. Acid Blue 225 and C.I. Acid Violet 109, were used as models to explore the feasibility of using the horseradish peroxidase enzyme (HRP) in the practical decolorization of anthraquinonic dyes in wastewater. The influence of process parameters such as enzyme concentration, hydrogen peroxide concentration, temperature, dye concentration, and pH was examined. The pH and temperature activity profiles were similar for decolorization of both dyes. Under the optimal conditions, 94.7% of C.I. Acid Violet 109 from aqueous solution was decolorized (treatment time 15 min, enzyme concentration 0.15 IU/mL, hydrogen peroxide concentration 0.4 mM, dye concentration 30 mg/L, pH 4, and temperature 24°C) and 89.36% of C.I. Acid Blue 225 (32 min, enzyme concentration 0.15 IU/mL, hydrogen peroxide concentration 0.04 mM, dye concentration 30 mg/L, pH 5, and temperature 24°C). The mechanism of both reactions has been proven to follow the two substrate ping-pong mechanism with substrate inhibition, revealing the formation of a nonproductive or dead-end complex between dye and HRP or between H2O2and the oxidized form of the enzyme. Both chemical oxygen demand and total organic carbon values showed that there was a reduction in toxicity after the enzymatic treatment. This study verifies the viability of use of horseradish peroxidase for the wastewaters treatment of similar anthraquinonic dyes.

scholarly journals Au Modified F-TiO2 for Efficient Photocatalytic Synthesis of Hydrogen Peroxide

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3844
Author(s):  
Lijuan Li ◽  
Bingdong Li ◽  
Liwei Feng ◽  
Xiaoqiu Zhang ◽  
Yuqian Zhang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction System ◽  
Reaction Medium ◽  
Pure Tio2 ◽  
H2o2 Production ◽  
Tio2 Photocatalyst ◽  
H2o2 Decomposition ◽  
Spin Resonance ◽  
Photocatalytic Synthesis

In this work, Au-modified F-TiO2 is developed as a simple and efficient photocatalyst for H2O2 production under ultraviolet light. The Au/F-TiO2 photocatalyst avoids the necessity of adding fluoride into the reaction medium for enhancing H2O2 synthesis, as in a pure TiO2 reaction system. The F− modification inhibits the H2O2 decomposition through the formation of the ≡Ti–F complex. Au is an active cocatalyst for photocatalytic H2O2 production. We compared the activity of TiO2 with F− modification and without F− modification in the presence of Au, and found that the H2O2 production rate over Au/F-TiO2 reaches four times that of Au/TiO2. In situ electron spin resonance studies have shown that H2O2 is produced by stepwise single-electron oxygen reduction on the Au/F-TiO2 photocatalyst.

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