scholarly journals Peroxidase, an Example of Enzymes with Numerous Applications

2021 ◽  
pp. 11-22
Author(s):  
I. Nnamchi, Chukwudi ◽  
C. Amadi Onyetugo ◽  
I. Nnaji Amarachi
Keyword(s):  
Hydrogen Peroxide ◽  
Large Family ◽  
Dye Decolorization ◽  
Product Formation ◽  
Thyroid Peroxidase ◽  
Colour Product ◽  
Paper And Pulp ◽  
Living Organisms ◽  
The Many ◽  
Heme Peroxidases

The enzyme peroxidase is a heme or iron-porphyrin protein that belongs to a large family of enzymes called the oxidoreductases. Their function mainly is to oxidize molecules at the expense of hydrogen peroxide. They are widely distributed in living organisms, and usually show dramatic colour-product formation as a result of their catalytic effect. They generally catalyse many oxygen transfer reactions involving hydrogen peroxide or anyone of the many other peroxides as electron acceptors and substrates. This ability of reducing peroxides at the expense of electron donating substrates is what marks peroxidases as ubiquitous and very important enzymes with many biotechnological applications. Not surprisingly therefore peroxidases play many important roles in different areas of biotechnology. Among others, these include such diverse areas as bioenergy, bioremediation, dye decolorization, humic acid degradation, paper and pulp and textile industries among many others. An important reason for this ability is the different areas from which peroxidases could be sourced as the function of many peroxidases show variations according to its source. This is a character that differentiates peroxidases from many other biological catalysts. Among the many different types of peroxidases are the heme peroxidases which mainly come from plants and fungi and include among others lignin peroxidases, manganese peroxidases and versatile peroxidases.  Some important types of peroxidases from humans and animals are glutathione peroxidase, thyroid peroxidase, lactoperoxidase, salivary peroxidase and thyroid peroxidase. 

scholarly journals Transformation of Contaminants of Emerging Concern (CECs) during UV-Catalyzed Processes Assisted by Chlorine

Catalysts ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1432
Author(s):  
Edyta Kudlek
Keyword(s):  
Hydrogen Peroxide ◽  
Water Samples ◽  
Water Environment ◽  
Toxicity Assessment ◽  
Contaminants Of Emerging Concern ◽  
Post Processing ◽  
Processing Water ◽  
Living Organisms ◽  
Trace Concentrations ◽  
By Products

Every compound that potentially can be harmful to the environment is called a Contaminant of Emerging Concern (CEC). Compounds classified as CECs may undergo different transformations, especially in the water environment. The intermediates formed in this way are considered to be toxic against living organisms even in trace concentrations. We attempted to identify the intermediates formed during single chlorination and UV-catalyzed processes supported by the action of chlorine and hydrogen peroxide or ozone of selected contaminants of emerging concern. The analysis of post-processing water samples containing benzocaine indicated the formation of seven compound intermediates, while ibuprofen, acridine and β-estradiol samples contained 5, 5, and 3 compound decomposition by-products, respectively. The number and also the concentration of the intermediates decreased with the time of UV irradiation. The toxicity assessment indicated that the UV-catalyzed processes lead to decreased toxicity nature of post-processed water solutions.

scholarly journals Upconversion-based nanosystems for fluorescence sensing of pH and H2O2

2021 ◽  
Author(s):  
Chunning Sun ◽  
Michael Gradzielski
Keyword(s):  
Reactive Oxygen Species ◽  
Hydrogen Peroxide ◽  
Excitation Energy ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Fluorescence Sensing ◽  
Living Organisms

Hydrogen peroxide (H2O2), a key reactive oxygen species, plays an important role in living organisms, industrial and environmental fields. Here, a non-contact upconversion nanosystem based on the excitation energy attenuation...

Nature of Soils and Soil Development

2007 ◽  
Author(s):  
Earl B. Alexander ◽  
Roger G. Coleman ◽  
Todd Keeler-Wolfe ◽  
Susan P. Harrison
Keyword(s):  
Lower Limit ◽  
Total Mass ◽  
Ground Surface ◽  
Root Penetration ◽  
Unconsolidated Material ◽  
Below Ground ◽  
Porous Soil ◽  
Living Organisms ◽  
Bacteria And Fungi ◽  
The Many

We walk on soils frequently, but we seldom observe them. Soils are massive, even though they are porous. Soil 1m (40 inches) deep over an area of 1 hectare (2.5 acres) might weigh 10,000–15,000 metric tons. It is teeming with life. There are trillions, or quadrillions, of living organisms (mostly microorganisms), representing thousands of species, in each square meter of soil (Metting 1993). In fact, species diversity, or number of species, may be greater below ground than above ground. We seldom see these organisms because we seldom look below ground or dig into it. The many worms and insects one finds digging in a garden are a small fraction of the species in soils because the greatest diversity of soil-dwelling species exists among microscopic insects, mites, roundworms (or nematodes), and fungi. Even though individual organisms in soils are mostly very small or microscopic, the total mass of living organisms in a hectare of soil, excluding plant roots, may be 1–5 or 10 metric tons. More than one-half of that biomass is bacteria and fungi. Living microorganism biomass generally accounts for about 1%–5% of the organic carbon and about 2%–6% of the nitrogen in soils (Lavelle and Spain 2001). The upper limit of soil is the ground surface of the earth. The lower limit is bedrock for engineers, or the depth of root penetration for edaphologists. Unconsolidated material that engineers call soil can be called “regolith” (Merrill 1897, Jackson 1997) to distinguish it from the soil of pedologists and edaphologists. Regolith may consist of disintegrated bedrock, gravel, sand, clay, or other materials that have not been consolidated to form rock. Pedologists investigate the upper part of regolith, where changes are effected by exchanges of gases between soil and aboveground atmosphere and by biological activity. This soil of pedologists may coincide with that of edaphologists or include more regolith. In fact, the lower limit of soil that pedologists investigate is arbitrary, unless this limit is a contact with bedrock that is practically impenetrable with pick and shovel.

The interaction of silver ions and hydrogen peroxide in the inactivation of E. coli: a preliminary evaluation of a new long acting residual drinking water disinfectant

1995 ◽  
Vol 31 (5-6) ◽  
pp. 123-129 ◽  
Author(s):  
Rami Pedahzur ◽  
Ovadia Lev ◽  
Badri Fattal ◽  
Hillel I. Shuval
Keyword(s):  
Hydrogen Peroxide ◽  
Drinking Water ◽  
Distribution Systems ◽  
Residual Effect ◽  
Silver Ions ◽  
Product Formation ◽  
Preliminary Evaluation ◽  
E Coli ◽  
The Usa ◽  
K 12

The inactivation efficiencies of silver ions, hydrogen peroxide and their combination was studied as part of a performance evaluation of the combined disinfectant for drinking water applications. The major advantages of such combined disinfectant include, low toxicity of its components, long lasting residual effect and low disinfection by product formation. Specific strains of E. coli (E. coli-B (SR-9) and E. coli K-12) were used in this study as target microorganisms and the separate and combined inactivation efficiencies of silver and hydrogen peroxide were evaluated at different concentrations and exposure durations. Both, silver and hydrogen peroxide exhibited a significant inactivation performance even at concentrations that do not pose any health risk according to the EEC, WHO and the USEPA (the USEPA Maximum Contaminant Level (MCL) of silver is 90 ppb, and currently, there is no MCL for hydrogen peroxide but it is approved as a food additive in the USA). Combinations of 1:1000 silver:hydrogen peroxide (w) exhibited higher inactivation performance as compared with each of the disinfectants alone and in some cases a synergistic effect was observed, i.e., the combined disinfectant exhibited higher inactivation performance than the sum of the inactivation levels of the separate disinfectants. Thus, for example, one hour exposure to 30 ppb silver, 30 ppm hydrogen peroxide and their combination yielded 2.87, 0.65 and 5 logs of inactivation respectively. While the rate of inactivation shown by this combined disinfectant, now available commercially in a stabilized formulation is relatively slow, it may well hold promise as a secondary disinfectant providing long lasting residuals and biofilm control required for distribution systems. Its disinfection action may be similar to chloramines, the use of which has been recently outlawed in France and in Germany and which are now under careful scrutiny in other countries due to the formation of undesirable by-products.

Alizarin-based molecular probes for the detection of hydrogen peroxide and peroxynitrite

The Analyst ◽  
2021 ◽  
Author(s):  
Minglu Li ◽  
Peng Lei ◽  
Shengmei Song ◽  
Shaomin Shuang ◽  
Chuan Dong
Keyword(s):  
Hydrogen Peroxide ◽  
Large Family ◽  
Molecular Probes

Phenol fluorophores are a large family of fluorophores, which have attracted more and more attention in the design of probes.

scholarly journals Expression of a Heterologous Manganese Superoxide Dismutase Gene in Intestinal Lactobacilli Provides Protection against Hydrogen Peroxide Toxicity

2004 ◽  
Vol 70 (8) ◽  
pp. 4702-4710 ◽  
Author(s):  
Jose M. Bruno-Bárcena ◽  
Jason M. Andrus ◽  
Stephen L. Libby ◽  
Todd R. Klaenhammer ◽  
Hosni M. Hassan
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Manganese Superoxide Dismutase ◽  
Lactobacillus Reuteri ◽  
Shuttle Vector ◽  
Streptococcus Thermophilus ◽  
Gene Encoding ◽  
Superoxide Dismutase Gene ◽  
Living Organisms ◽  
Biochemical Analyses

ABSTRACT In living organisms, exposure to oxygen provokes oxidative stress. A widespread mechanism for protection against oxidative stress is provided by the antioxidant enzymes: superoxide dismutases (SODs) and hydroperoxidases. Generally, these enzymes are not present in Lactobacillus spp. In this study, we examined the potential advantages of providing a heterologous SOD to some of the intestinal lactobacilli. Thus, the gene encoding the manganese-containing SOD (sodA) was cloned from Streptococcus thermophilus AO54 and expressed in four intestinal lactobacilli. A 1.2-kb PCR product containing the sodA gene was cloned into the shuttle vector pTRK563, to yield pSodA, which was functionally expressed and complemented an Escherichia coli strain deficient in Mn and FeSODs. The plasmid, pSodA, was subsequently introduced and expressed in Lactobacillus gasseri NCK334, Lactobacillus johnsonii NCK89, Lactobacillus acidophilus NCK56, and Lactobacillus reuteri NCK932. Molecular and biochemical analyses confirmed the presence of the gene (sodA) and the expression of an active gene product (MnSOD) in these strains of lactobacilli. The specific activities of MnSOD were 6.7, 3.8, 5.8, and 60.7 U/mg of protein for L. gasseri, L. johnsonii, L. acidophilus, and L. reuteri, respectively. The expression of S. thermophilus MnSOD in L. gasseri and L. acidophilus provided protection against hydrogen peroxide stress. The data show that MnSOD protects cells against hydrogen peroxide by removing O2 ·− and preventing the redox cycling of iron. To our best knowledge, this is the first report of a sodA from S. thermophilus being expressed in other lactic acid bacteria.

Effect of exogenous hydrogen peroxide on iodide transport and iodine organification in FRTL-5 rat thyroid cells

1993 ◽  
Vol 129 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Ge Chen ◽  
A Eugene Pekary ◽  
Masahiro Sugawara ◽  
Jerome M Hershman
Keyword(s):  
Hydrogen Peroxide ◽  
Cyclic Adenosine Monophosphate ◽  
Adenosine Monophosphate ◽  
Thyroid Peroxidase ◽  
Thyroid Cells ◽  
Iodide Transport ◽  
Biphasic Effect ◽  
Rat Thyroid ◽  
Camp Levels ◽  
Hormone Formation

Hydrogen peroxide plays an important role in the regulation of iodination and thyroid hormone formation. In the present study, the effect of exogenous H2O2 on 125I transport and organification was investigated in FRTL-5 rat thyroid cells. Less than 20 passages after subcloning, cells in 24-well plates (6 × 104 cells/well) were maintained in a thyrotropin (TSH)-containing medium (6H) for 3 days. A TSH-free medium (5H) was then used for the next 7 days. A 1-h exposure to H2O2 stimulated 125I transport and 125I organification at 0.1–0.5 mmol/l H2O2 and had a toxic effect on FRTL-5 cells at 5 mmol/l. Hydrogen peroxide (0.5 mmol/l) augmented the iodide transport and iodine organification induced by TSH (333U/l) by two- and threefold, respectively. The biphasic effect of H2O2 was blocked totally by 5–200 μg/l of catalase. Catalase by itself did not influence TSH-mediated 125I transport and 125I organification. Hydrogen peroxide (0.5 mmol/l) added to cells in 5H medium increased Na+K+-ATPase activity twofold. Ouabain (1 mmol/l), an inhibitor of Na+K +-ATPase, completely inhibited the twofold increase in 125I transport induced by 0.5 mmol/l H2O2 but only inhibited H2O2-induced 125I organification by 28%. Methimazole (1 mmol/l), an inhibitor of thyroid peroxidase, had no effect on H2O2-mediated 125I transport but totally blocked the fivefold rise in 125I organification induced by 0.5 mmol/1 H2O2. The effect of H2O2 on intracellular cyclic adenosine monophosphate (cAMP) levels also was studied. Hydrogen peroxide (0.5 mmol/l) decreased baseline and 160 mU/l TSH-induced cAMP levels by 35 and 87%, respectively, while a 3-h incubation with 0.5 mmol/l H2O2 increased Na + K +-ATPase in 5H and 6H media. We conclude that H2O2 plays an important role in the regulation of iodide transport and organification and also may affect signal transduction and the electrochemical gradient in thyroid cells. Our results also provide evidence that functional thyroid peroxidase activity is present in FRTL-5 cells.

scholarly journals Advanced oxidation processes for decolorization of aqueous solution containing acid red G azo dye

2004 ◽  
Vol 2 (4) ◽  
pp. 573-588 ◽  
Author(s):  
Mioara Surpăţeanu ◽  
Carmen Zaharia
Keyword(s):  
Hydrogen Peroxide ◽  
Azo Dye ◽  
Catalytic Effect ◽  
Dye Decolorization ◽  
Alkaline Media ◽  
Ferrous Ions ◽  
Oxidant Concentration ◽  
Wide Range ◽  
Neutral Media ◽  
Acid Red G

AbstractSome investigations concerning the decolorization of Acid Red G azo dye by photooxidation with hydrogen peroxide were performed. The influences of pH, oxidant concentration, and the presence of Fe2+ or other metal ions (Co2+, Cu2+, Ni2+, Mn2+) as potential catalysts, were investigated. The best results were obtained in the presence of ferrous ions in acid and neutral media. The other ions are not as effective as Fe2+ for dye decolorization. Co2+ and Cu2+ ions have a catalytic action, at low concentration, within a wide range of pH. Ni2+ and Mn2+ ions have no catalytic effect in photooxidation with hydrogen peroxide at acid Ni2+ and Mn2+ ions have no catalytic effect in photooxidation with hydrogen peroxide at acid pH values, but show a weak action in alkaline media.

The Terminal Oxidase in the Marine Bacterium Pseudomonas nautica 617

1997 ◽  
Vol 17 (3) ◽  
pp. 343-346 ◽  
Author(s):  
Helen Simpson ◽  
Michel Denis ◽  
Francesco Malatesta
Keyword(s):  
Hydrogen Peroxide ◽  
Carbon Monoxide ◽  
Oxygen Reduction ◽  
Epr Spectroscopy ◽  
Marine Bacterium ◽  
Large Family ◽  
Terminal Oxidase ◽  
Quinol Oxidase ◽  
Terminal Oxidases ◽  
Production Of Hydrogen

The molecular properties of a novel membrane quinol oxidase from the marine bacterium Pseudomonas nautica 617 are presented. The protein contains 2b hemes/mole which may be distinguished by EPR spectroscopy but not by optical spectroscopy and electrochemistry. Respiration, though being cyanide insensitive, is not inhibited by carbon monoxide and oxygen reduction is carried out only half-way with production of hydrogen peroxide. The terminal oxidase represents, therefore, a unique example in the large family of terminal oxidases known up to date.

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