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Concept

Catalase

Related publications (21)

Identifying the mediators of intracellular E. coli inactivation under UVA light: The (photo) Fenton process and singlet oxygen

César Pulgarin, Stefanos Giannakis

Solar disinfection (SODIS) was probed for its underlying mechanism. When Escherichia coli was exposed to UVA irradiation, the dominant solar fraction acting in SODIS process, cells exhibited a shoulder before death ensued. This profile resembles cell killi ...

PERGAMON-ELSEVIER SCIENCE LTD2022

Permanganate Reduction by Hydrogen Peroxide: Formation of Reactive Manganese Species and Superoxide and Enhanced Micropollutant Abatement

Urs von Gunten

Permanganate (MnO4-, Mn(VII)) is widely applied at the initial stage of water treatment to, e.g., abate taste and odor compounds, Mn(II) and Fe(II). However, its selectivity limits its application for micropollutant abatement. Hydrogen peroxide (H2O2), whi ...

AMER CHEMICAL SOC2021

Employing bacterial mutations for the elucidation of photo-Fenton disinfection: Focus on the intracellular and extracellular inactivation mechanisms induced by UVA and H2O2

César Pulgarin, Stefanos Giannakis

The bacterial inactivation mechanisms by solar light and the photo-Fenton process is still a matter of debate. In this study, we bring evidence towards the elucidation of the mechanisms that govern photo-Fenton disinfection at near-neutral pH. With the use ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Persulfate-Based Advanced Oxidation: Critical Assessment of Opportunities and Roadblocks

Urs von Gunten

Reports that promote persulfate-based advanced oxidation process (AOP) as a viable alternative to hydrogen peroxide-based processes have been rapidly accumulating in recent water treatment literature. Various strategies to activate peroxide bonds in persul ...

AMER CHEMICAL SOC2020

Requirements for DNA bubble structure for efficient cleavage by helix-two-turn-helix DNA glycosylases

Kristina Makasheva

Oxidative DNA lesions, constantly generated by both endogenous and environmentally induced reactive oxygen species, are removed via the base excision repair pathway. In bacteria, Fpg and Nei DNA glycosylases, belonging to the helix-two-turn-helix (H2TH) st ...

2020

Reaction pathway of oxygen evolution on Pt(111) revealed through constant Fermi level molecular dynamics

Alfredo Pasquarello, Assil Bouzid, Patrick Gono

The pathway of the oxygen evolution reaction at the Pt(111)/water interface is disclosed through constant Fermi level molecular dynamics. Upon the application of a positive bias potential H2Oads and OHads adsorbates are found to arrange in a hexagonal latt ...

2019

New evidence for Cu-decorated binary-oxides mediating bacterial inactivation/mineralization in aerobic media

César Pulgarin, Juan Kiwi, Sami Rtimi, Michaël Bensimon

Binary oxide semiconductors TiO2-ZrO2 and Cu-decorated TiO2-ZrO2 (TiO2-ZrO2-Cu) uniform films were sputtered on polyester (PES). These films were irradiated under low intensity solar simulated light and led to bacterial inactivation in aerobic and anaerobi ...

Elsevier2016

The Molecular Mechanism of the Catalase-like Activity in Horseradish Peroxidase

Ursula Röthlisberger, Pablo Campomanes Ramos

Horseradish peroxidase (HRP) is one of the most relevant peroxidase enzymes, used extensively in immunochemistry and biocatalysis applications. Unlike the closely related catalase enzymes, it exhibits a low activity to disproportionate hydrogen peroxide (H ...

2015

Differential coral bleaching—Contrasting the activity and response of enzymatic antioxidants in symbiotic partners under thermal stress

Thomas Krüger

Mass coral bleaching due to thermal stress represents a major threat to the integrity and functioning of coral reefs. Thermal thresholds vary, however, between corals, partly as a result of the specific type of endosymbiotic dinoflagellate (Symbiodinium sp ...

Elsevier2015

Neutral solar photo-Fenton degradation of 4-nitrophenol on iron-enriched hybrid montmorillonite-alginate beads (Fe-MABs)

César Pulgarin

Hybrid montmorillonite-alginate beads (MABs) were prepared by the ion-gelation method from alginate and montmorillonite clay suspension dropped in a calcium chloride solution. Similarly, iron-enriched beads (Fe-MABs) were prepared using iron-exchanged mont ...

Elsevier Science Sa2014

Electrochemical oxygen reduction at soft interfaces catalyzed by the transfer of hydrated lithium cations

Hubert Girault, Pekka Eero Peljo, Haiqiang Deng, Thomas James Stockmann

The oxygen reduction reaction by decamethylferrocene (DMFc), triggered by hydrophilic metallic cations behaving as Lewis acids towards water molecules in a homogeneous organic phase reaction, was investigated using cyclic voltammetry at the water|1,2-dichl ...

Elsevier2014

Oxygen and hydrogen peroxide reduction by 1,2-diferrocenylethane at a liquid/liquid interface

Hubert Girault, Fernando Cortes Salazar, Pekka Eero Peljo, Peiyu Ge, Haiqiang Deng

Molecular oxygen and hydrogen peroxide reduction by 1,2-diferrocenylethane (DFcE) was investigated at a polarized water/1,2-dichloroethane (W/DCE) interface. The overall reaction points to a proton-coupled electron transfer (PCET) mechanism, where the firs ...

Elsevier2012

Taxonomic characterisation of Pseudomonas strain L48 and formal proposal of Pseudomonas entomophila sp nov

Bruno Lemaitre

An entomopathogenic, Gram-negative bacterium isolated from a female specimen of the fruit fly Drosophila melanogaster was taxonomically characterised. Strain L48(T) was strictly aerobic, non-fermentative, oxidase and catalase positive, rod-shaped, and moti ...

Elsevier2012

Comparison of Three Methods of Biocompatible Multi-Walled Carbon Nanotubes Confinement for the Development of Implantable Amperometric Adenosine-5′-Triphosphate Biosensors

Giovanni De Micheli, Sandro Carrara, Andrea Cavallini

An amperometric biosensor for adenosine 5 -triphosphate (ATP) was developed applying a competitive assay of two glucose converting enzymes: glucose oxidase (GOD) and hexokinase (HEX). Competition between GOD and HEX for glucose in presence of ATP, lead to ...

American Scientific Publishers2011

Oxygen reduction catalyzed by a fluorinated tetraphenylporphyrin free base at liquid/liquid interfaces

Hubert Girault, Anne-Clémence Corminboeuf, Bin Su, Manuel Alejandro Méndez Agudelo, Imren Hatay

The diprotonated form of a fluorinated free base porphyrin, namely 5-(p-aminophenyl)-10,15,20-tris(pentafluorophenyl)porphyrin (H(2)FAP), can catalyze the reduction of oxygen by a weak electron donor, namely ferrocene (Fc). At a water/1,2-dichloroethane in ...

American Chemical Society2010

RETRACTED: On the enzymatic activity of catalase: an iron L-edge X-ray absorption study of the active centre

Majed Chergui

Catalase and methaemoglobin have very similar haem groups, which are both ferric, yet catalase decomposes hydrogen peroxide to water and oxygen very efficiently, while methaemoglobin does not. Structural studies have attributed this behaviour to their diff ...

Royal Society of Chemistry2010

Oxygen and proton reduction by decamethylferrocene in non-aqueous acidic media

Hubert Girault, Anne-Clémence Corminboeuf, Bin Su, Manuel Alejandro Méndez Agudelo, Peiyu Ge, Imren Hatay

Experimental studies and density functional theory (DFT) computations suggest that oxygen and proton reduction by decamethylferrocene (DMFc) in 1,2-dichloroethane involves protonated DMFc, DMFcH+, as an active intermediate species, producing hydrogen perox ...

Royal Society of Chemistry2010

Detection of hydrogen peroxide produced at a liquid/liquid interface using scanning electrochemical microscopy

Hubert Girault, Fernando Cortes Salazar, Bin Su

Scanning electrochemical microscopy (SECM) was used to monitor in situ hydrogen peroxide (H2O2) produced at a polarized water/1,2-dichloroethane (DCE) interface. The water/DCE interface was formed between a DCE droplet containing decamethylferrocene (DMFc) ...

Elsevier2009

Proton Pump for O2 Reduction Catalyzed by 5,10,15,20- Tetraphenylporphyrinatocobalt(II)

Hubert Girault, Bin Su

The role of 5,10,15,20-tetraphenylporphyrinatocobalt(II) ([Co-(tpp)]) as a catalyst on molecular oxygen (O2) reduction by ferrocene (Fc) and its two derivatives, 1,1’-di-methylferrocene (DFc) and decamethylferrocene (DMFc) at a polarized water¦1,2-dichloro ...

2009

Generation of OH radicals at palladium oxide nanoparticle modified electrodes, and scavenging by fluorescent probes and antioxidants

Hubert Girault, Junqiu Liu

The reduction of palladium oxide nanoparticles in the presence of hydrogen peroxide or dissolved oxygen gives rise to a catalytic reduction current dependent on the hydrogen peroxide concentration or the oxygen concentration. Using terephthalic acid as an ...

2008