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1.
Chemosphere ; 255: 127041, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32679635

RESUMO

Microplastics pollution in farmlands has become a major concern. However, few studies have assessed the effects of microplastics on higher plants. In this study, we investigated the influence of polystyrene nanoplastics (PSNPs, 50 mg L-1), with four different particle sizes (100, 300, 500, and 700 nm), on the physiological and biochemical indexes of cucumber leaves. The biomass of cucumber plants significantly decreased after exposure to 300 nm PSNPs. Similarly, the chlorophyll a, chlorophyll b, soluble sugar, carotenoid, and proline content, as well as the fluorescence of cucumber leaves were significantly reduced by 100 nm PSNPs. Malondialdehyde, proline, peroxidase gene expression and enzyme activity, and hydrogen peroxide content significantly increased in cucumber leaves exposed to 700 nm PSNPs. In addition, increasing PSNPs particle size led to decreased relative expression levels and activities of the major antioxidant enzymes superoxide dismutase and catalase, while vitamin C and soluble protein content significantly increased. Overall, our results indicated that PSNPs affect the photosynthetic, antioxidant, and sugar metabolism systems of cucumber leaves, with the latter clearly affecting the total biomass of cucumber plants. The benzene ring resulting from the degradation of PSNPs in cucumber leaves may be the main factor affecting chlorophyll metabolism and sugar metabolism. Our findings provide a scientific basis for the risk assessment of PSNPs exposure in soil-plant systems.


Assuntos
Cucumis sativus/fisiologia , Poliestirenos/toxicidade , Poluentes do Solo/toxicidade , Antioxidantes/metabolismo , Carotenoides/metabolismo , Catalase/metabolismo , Clorofila , Clorofila A , Cucumis sativus/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Malondialdeído/metabolismo , Peroxidases/metabolismo , Fotossíntese/efeitos dos fármacos , Folhas de Planta/metabolismo , Plásticos/metabolismo , Poliestirenos/metabolismo , Superóxido Dismutase/metabolismo
2.
Chemosphere ; 250: 126296, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32135437

RESUMO

In some environments, a number of crops, notably maize and nuts can be contaminated by aflatoxin B1 and related compounds resulting from the growth of aflatoxin-producing Aspergilli. Fungal peroxidases have been shown to degrade a number of mycotoxins, including aflatoxin B1 (AFB1). Therefore, the purpose of this study was to investigate the in vitro enzymatic degradation AFB1 by a recombinant type B dye decolorizing peroxidase (Rh_DypB). Analysis of the reaction products by HPLC-MS analysis showed that under optimized conditions AFB1 was efficiently transformed by Rh_DypB, reaching a maximum of 96% conversion after 4 days of reaction at 25 °C. Based on high resolution mass spectrometry analysis, AFB1 was demonstrated to be quantitatively converted to AFQ1, a compound with a significantly lower toxicity. A number of low molecular mass compounds were also present in the final reaction mixture in small quantities. The results presented in this study are promising for a possible application of the enzyme Rh_DypB for aflatoxin reduction in feed.


Assuntos
Aflatoxina B1/metabolismo , Peroxidase/metabolismo , Aflatoxinas , Corantes , Modelos Químicos , Micotoxinas , Peroxidases , Zea mays/química
3.
Ann Parasitol ; 66(1): 13-18, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32198991

RESUMO

Two predominant forms of cutaneous leishmaniosis are anthroponotic CL (ACL) and zoonotic CL (ZCL) caused by Leishmania (L.) tropica and L. major in Iran and many countries, respectively. Since differential gene expression play an important role in outcome of the infection, we compared relative gene expression value of pyruvate kinase (PyrK) and tryparedoxin peroxidase (TryP) in metacyclic forms of Iranian isolates of L. major and L. tropica. Clinical isolates of CL patients were sampled in endemic foci of Iran and identified by PCR-RFLP. Then, we employed real-time PCR to evaluation of the expression level of PyrK and Tryp genes in L. major and L. tropica. By this comparison, up-regulation of PyrK and Tryp genes was observed in metacyclic stage. Moreover, the average mRNA expression of PyrK and Tryp genes in L. major was 1.69 and 3.72 folds of its expression in L. tropica isolates. The results of this study could open the new window for further investigations of the correspondence between parasite gene expression level and disease pathology. Species-specific parasite factors contributing to virulence and pathogenicity in the host may be mostly due to the some of the differential regulation of conserved genes between species.


Assuntos
Regulação Enzimológica da Expressão Gênica , Leishmania tropica , Peroxidases , Proteínas de Protozoários , Piruvato Quinase , Humanos , Irã (Geográfico) , Leishmania tropica/enzimologia , Leishmania tropica/genética , Leishmaniose Cutânea/parasitologia , Estágios do Ciclo de Vida/genética , Peroxidases/genética , Proteínas de Protozoários/genética , Piruvato Quinase/genética , Reação em Cadeia da Polimerase em Tempo Real
4.
Chemosphere ; 252: 126513, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32203784

RESUMO

Plants are known to remediate dyes, metals and emerging contaminants from wastewaters. Vetiveria zizanioides, a perennial bunchgrass showed removal of Remazol Red (RR, 100 mg/L) up to 93% within 40 h. Root and shoot tissues of V. zizanioides revealed induction in dye degrading enzymes viz. lignin peroxidase by 2.28 and 1.43, veratryl alcohol oxidase 2.72 and 1.60, laccase 6.15 and 3.55, and azo reductase 2.17 and 2.65-fold, respectively, during RR decolorization. Substantial increase was observed in the contents of chlorophyll a, chlorophyll b, and carotenoids in the plant leaves during treatment. Anatomical studies of roots, HPLC and GC-MS analysis of metabolites, and phytotoxicity assessment confirmed phytotransformation of RR into nontoxic metabolites. Floating phytobed with V. zizanioides treated textile wastewater (400 L) effectively and reduced ADMI, COD, BOD, TDS, and TSS by 74, 74, 81, 66 and 47%, respectively within 72 h. In-situ treatment of textile wastewater for 5 days in constructed furrows planted with semiaquatic plants, V. zizanioides, Ipomoea aquatica and its consortium-VI decreased ADMI by 68, 61 and 76%, COD by 75, 74 and 79%, BOD by 73, 71 and 84%, TDS by 77, 75 and 83%, and TSS by 34, 31 and 51%, respectively. This treatment was also useful to remove arsenic, cadmium, chromium and lead from wastewater. Overall observation suggests wise strategy to use this plantation in the furrows of high rate transpiration system and phytobeds in deep water for textile wastewater treatment.


Assuntos
Eliminação de Resíduos Líquidos/métodos , Biodegradação Ambiental , Clorofila A , Corantes/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Lacase , Peroxidases , Indústria Têxtil , Têxteis , Águas Residuárias
5.
Chemosphere ; 251: 126366, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32145575

RESUMO

In this study, the effects of excess nickel (Ni) (100 µM and 200 µM) on growth, antioxidant production, fatty acid, organic and amino acids profiles were examined in Lemna minor L. After 7 days of Ni treatment, chlorosis, growth inhibition and ROS overproduction were observed, accompanied by Ni accumulation. Interestingly, decreased malondialdehyde (MDA) levels were recorded in fronds upon Ni exposure. Fatty acid profiles in Ni-treated L. minor were characterized by increases in saturated- and decreases in unsaturated fatty acids. Ni excess increased the activities of antioxidant enzymes such as superoxide dismutase (SOD), guiacol peroxidase (GPX), and glutathione reductase (GR), and non-enzymatic antioxidants such as glutathione (GSH) and ascorbic acid (AsA); however, deactivation of ascorbate peroxidase (APX) and catalase (CAT) activities were also observed. Disruption of amino acid metabolism in Ni-exposed fronds was evidenced by the accumulation of cysteine, arginine, threonine, valine, isoleucine, leucine, lysine and phenylalanine, as well as reduced levels of tyrosine, alanine, aspartate and proline. Approximately 299%-396%, 139%-254% and 56%-97% concentration increments in citric, malic and oxalic acids, respectively, were concomitantly observed with significant decreases in tartaric, acetic, and fumaric acids in fronds subjected to Ni stress. Taken together, these results indicated that Ni stress induced negative effects on plant physiological, biochemical and morphological processes; however, it is likely that the coordination of metabolites and antioxidants may ameliorate the damaging effects of Ni accumulation.


Assuntos
Araceae/metabolismo , Níquel/metabolismo , Antioxidantes/metabolismo , Araceae/efeitos dos fármacos , Ascorbato Peroxidases/metabolismo , Ácido Ascórbico/farmacologia , Catalase/metabolismo , Ácidos Graxos/metabolismo , Glutationa/metabolismo , Glutationa Redutase/metabolismo , Malondialdeído/metabolismo , Oxirredução , Peroxidase/metabolismo , Peroxidases/metabolismo , Prolina/metabolismo , Superóxido Dismutase/metabolismo
6.
Chemosphere ; 249: 126121, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32065994

RESUMO

Metal accumulation in soil could lead to severe damage to plants, animals, and humans. The present work aims to evaluate the effects of nickel (Ni) exposure on Medicago sativa at physiological, biochemical, and transcriptomic levels. Plants were exposed to five increasing concentrations of Ni (0, 50, 150, 250, and 500 mg/kg) for 60 days. Agronomic parameters (fresh and dry matter) and chlorophyll content (Chl) were determined in an alfalfa plant. Chemical analyses were conducted, involving the determination of Ni loads in plants (roots and shoots). Moreover, malondialdehyde accumulation (MDA), glutathione-S-transferase (GST), and peroxidase activities, termed as oxidative stress biomarkers, were measured. The gene expression levels of Prx1C, GST, and phytochelatins (PCs) were determined at different nickel concentrations. Our results showed that Ni concentration in plants increased significantly along with Ni concentration in the soil. Regarding oxidative stress biomarkers, Ni contamination caused an increase in peroxidase and GST activities, with a remarkable accumulation of MDA, especially for the highest Ni concentration (500 mg/kg of Ni). Our data showed also a significant upregulation of Prx1C and GST genes in shoots and roots. The PCs' gene expression was significantly enhanced in response to the different nickel concentrations, suggesting their important role in Ni detoxification in alfalfa plants. Our data provided evidence about the clear toxicity of Ni, an often-underestimated trace element.


Assuntos
Medicago sativa/fisiologia , Níquel/toxicidade , Poluentes do Solo/toxicidade , Animais , Clorofila/metabolismo , Malondialdeído/metabolismo , Medicago sativa/efeitos dos fármacos , Oxirredução , Estresse Oxidativo/efeitos dos fármacos , Peroxidase/metabolismo , Peroxidases/metabolismo , Fitoquelatinas/metabolismo , Raízes de Plantas/metabolismo , Solo/química , Poluentes do Solo/metabolismo , Transcriptoma/efeitos dos fármacos
7.
Arch Virol ; 165(4): 809-822, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32103340

RESUMO

Oxidative stress is the process by which reactive molecules and free radicals are formed in cells. In this study, we report the blood-based gene expression profile of oxidative stress and antioxidant genes for identifying surrogate markers of liver tissue in chronic hepatitis C (CHC) patients by using real-time PCR. A total of 144 untreated patients diagnosed with CHC having genotype 3a and 20 healthy controls were selected for the present study. Liver biopsy staging and grading of CHC patients were performed using the METAVIR score. Total RNA was extracted from liver tissue and blood samples, followed by cDNA synthesis and real-time PCR. The relative expression of genes was calculated using the ΔΔCt method. The expression profile of 84 genes associated with oxidative stress and antioxidants was determined in liver tissue and blood samples. In liver tissue, 46 differentially expressed genes (upregulated, 27; downregulated, 19) were identified in CHC patients compared to normal samples. In blood, 61 genes (upregulated, 51; downregulated; 10) were significantly expressed in CHC patients. A comparison of gene expression in liver and whole blood showed that 20 genes were expressed in a similar manner in the liver and blood. The expression levels of commonly expressed liver and blood-based genes were also correlated with clinical factors in CHC patients. A receiver operating curve (ROC) analysis of oxidative stress genes (ALB, CAT, DHCR24, GPX7, PRDX5, and MBL2) showed that infections in patients with CHC can be distinguished from healthy controls. In conclusion, blood-based gene expression can reflect the behavior of oxidative stress genes in liver tissue, and this blood-based gene expression study in CHC patients explores new blood-based non-invasive biomarkers that represent liver damage.


Assuntos
Hepatite C Crônica/sangue , Fígado/metabolismo , Estresse Oxidativo , Adulto , Biomarcadores/sangue , Feminino , Regulação Neoplásica da Expressão Gênica , Hepatite C Crônica/genética , Humanos , Fígado/lesões , Masculino , Pessoa de Meia-Idade , Proteínas do Tecido Nervoso/sangue , Proteínas do Tecido Nervoso/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/sangue , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Peroxidases/sangue , Peroxidases/genética , Peroxirredoxinas/sangue , Peroxirredoxinas/genética , Adulto Jovem
8.
Water Res ; 174: 115637, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32105995

RESUMO

Oxidation is a widely used method in drinking water treatment to mitigate the membrane fouling caused by the natural organic matters (NOM) from the surface water during ultra-filtration (UF) and nano-filtration (NF) processes, and H2O2 is one of the common oxidants for it. However, the oxidation capability of H2O2 at neutral pH is lower, compared to the acidic and alkaline conditions. In order to improve the efficiency of NOM oxidation at neutral pH, a carbon-doped Fe3O4 peroxidase-like nanozyme (CFPN) was synthesized in this study and used as a high-performance catalyst for H2O2 to generate hydroxyl radical. The oxygen-containing groups on the carbon structure of CFPN can form an acidic microenvironment, allowing H2O2 to produce hydroxyl radical by catalysis in neutral conditions. The results of hydrophilicity analysis, zeta potential, high-performance liquid size exclusion chromatography (HPSEC), Fourier transform infrared spectrum (FTIR) and flux indicated that the hydroxyl radical can oxidize the hydrophobic matters of humic acid (HA) into hydrophilic matters by Fenton reaction or electrophilic addition reaction, which can mitigate the fouling of NF membranes. The results of the same test for the bovine serum albumin (BSA) indicated that the hydroxyl radical can mitigate the fouling of UF membranes by degrading the tertiary and secondary structures of BSA and partly oxidizing the side chain groups. In addition, two types of surface water samples were used to verify the above mechanism, and the results indicated that the hydroxyl radical treatment at neutral pH is a new viable and effective strategy to significantly mitigate the NOM fouling of UF and NF membranes.


Assuntos
Ultrafiltração , Purificação da Água , Carbono , Peróxido de Hidrogênio , Concentração de Íons de Hidrogênio , Membranas Artificiais , Peroxidase , Peroxidases
9.
Anal Chim Acta ; 1098: 148-154, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31948578

RESUMO

An iron-nickel bimetallic metal-organic framework (FeNi-MOF) with inner peroxidase-like activity as a support for enzyme immobilization was synthesized for the first time. And the GOx-mediated synthesis of mimic multienzyme system (GOx/FeNi-MOF) was obtained by a one-step biomimetic mineralization. FeNi-MOF played a dual role of a peroxidase mimic and a protective coating. Therefore, the obtained multienzyme system showed both peroxidase-like activity of FeNi-MOF and the biological activity of natural enzyme. FeNi-MOF acted as a peroxidase mimic, showing a higher affinity for hydrogen peroxide (H2O2). The enhanced catalytic activity of the FeNi-MOF may result from synergistic effect between iron and nickel. In addition, the GOx/FeNi-MOF was selected as a proof of concept and succeeded in a one-step colorimetric detection of glucose by tandem catalysis. A small amount of the product was used for glucose detection, and the detection range was 0.3-35 mM, which indicated that our sensor can meet the clinical needs for diagnose diabetes.


Assuntos
Produtos Biológicos/química , Materiais Biomiméticos/química , Enzimas Imobilizadas/química , Glucose/análise , Peróxido de Hidrogênio/química , Ferro/química , Estruturas Metalorgânicas/química , Níquel/química , Peroxidases/química , Produtos Biológicos/metabolismo , Materiais Biomiméticos/metabolismo , Catálise , Enzimas Imobilizadas/metabolismo , Peróxido de Hidrogênio/metabolismo , Peroxidases/metabolismo
10.
Nat Commun ; 11(1): 190, 2020 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-31929512

RESUMO

Exercise is among the most effective interventions for age-associated mobility decline and metabolic dysregulation. Although long-term endurance exercise promotes insulin sensitivity and expands respiratory capacity, genetic components and pathways mediating the metabolic benefits of exercise have remained elusive. Here, we show that Sestrins, a family of evolutionarily conserved exercise-inducible proteins, are critical mediators of exercise benefits. In both fly and mouse models, genetic ablation of Sestrins prevents organisms from acquiring metabolic benefits of exercise and improving their endurance through training. Conversely, Sestrin upregulation mimics both molecular and physiological effects of exercise, suggesting that it could be a major effector of exercise metabolism. Among the various targets modulated by Sestrin in response to exercise, AKT and PGC1α are critical for the Sestrin effects in extending endurance. These results indicate that Sestrin is a key integrating factor that drives the benefits of chronic exercise to metabolism and physical endurance.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Proteínas de Drosophila/metabolismo , Exercício Físico/fisiologia , Proteínas de Choque Térmico/metabolismo , Oxirredutases/metabolismo , Peroxidases/metabolismo , Animais , Proteínas de Ciclo Celular/genética , Diferenciação Celular , Drosophila , Proteínas de Drosophila/genética , Metabolismo Energético , Expressão Gênica , Proteínas de Choque Térmico/genética , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fibras Musculares Esqueléticas/citologia , Músculo Esquelético/metabolismo , Músculo Esquelético/fisiologia , Biogênese de Organelas , Oxirredutases/genética , Peroxidases/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Resistência Física/genética , Resistência Física/fisiologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo
11.
Arch Microbiol ; 202(4): 895-903, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31897538

RESUMO

This study investigated the regulatory role of Rhodopseudomonas palustris RP11 in alleviating TBBPA-induced harmful effects in soybean seedlings. In this study, the characteristics of growth promotion by strain RP11 were studied by analysing 5-aminolevulinic acid (ALA) and indole-3-acetic acid (IAA) production, as well as phosphorus-solubilizing and potassium-solubilizing ability. In the pot culture conditions, we tested whether strain RP11 improved soybean seedlings tolerance against TBBPA by measuring the root length and physiological parameters of the seedlings treated with strain RP11 and different concentration of TBBPA (0, 5, 50, 100, and 1000 mg/kg) together. The results showed that strain RP11 secreted IAA and ALA, and solubilized phosphate and potassium. In pot trials, strain RP11 increased the root length, chlorophyll content, carotenoid content, soluble sugar and protein content of soybean seedlings treated with TBBPA, in comparison with the seedlings treated only with TBBPA. Furthermore, strain RP11 induced the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD), decreased the malondialdehyde (MDA) content in soybean seedlings under TBBPA stress. It was concluded that strain RP11 alleviated TBBPA-induced harmful effects in soybean seedlings by the secretion of IAA and ALA, the accumulation of carotenoid, soluble sugar and soluble protein, and the induction of SOD, CAT and POD as well as nutrient adjustment of phosphorus and potassium levels.


Assuntos
Bifenil Polibromatos/metabolismo , Rodopseudomonas/metabolismo , Plântula/microbiologia , Soja/microbiologia , Catalase/metabolismo , Clorofila/metabolismo , Ácidos Indolacéticos/metabolismo , Malondialdeído/metabolismo , Peroxidase/metabolismo , Peroxidases/metabolismo , Bifenil Polibromatos/toxicidade , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Soja/efeitos dos fármacos , Soja/crescimento & desenvolvimento , Superóxido Dismutase/metabolismo
12.
Sci Total Environ ; 714: 136572, 2020 Apr 20.
Artigo em Inglês | MEDLINE | ID: mdl-31986384

RESUMO

Various organic pollutants so-called emerging pollutants (EPs), including active residues from pharmaceuticals, pesticides, surfactants, hormones, and personal care products, are increasingly being detected in numerous environmental matrices including water. The persistence of these EPs can cause adverse ecological and human health effects even at very small concentrations in the range of micrograms per liter or lower, hence called micropollutants (MPs). The existence of EPs/MPs tends to be challenging to mitigate from the environment effectively. Unfortunately, most of them are not removed during the present-day treatment plants. So far, a range of treatment processes and degradation methods have been introduced and deployed against various EPs and/or MPs, such as ultrafiltration, nanofiltration, advanced oxidation processes (AOPs) and enzyme-based treatments coupled with membrane filtrations. To further strengthen the treatment processes and to overcome the EPs/MPs effective removal dilemma, numerous studies have revealed the applicability and notable biocatalytic potentialities of laccases and peroxidases to degrade different classes of organic pollutants. Exquisite selectivity and unique catalytic properties make these enzymes powerful biocatalytic candidates for bio-transforming an array of toxic contaminants to harmless entities. This review focuses on the use of laccases and peroxidases, such as soybean peroxidase (SBP), horseradish peroxidase (HRP), lignin peroxidase (LiP), manganese peroxidase (MnP), and chloroperoxidase (CPO) as a greener oxidation route towards efficient and effective removal or degradation of EPs/MPs.


Assuntos
Poluentes Ambientais/análise , Biocatálise , Biodegradação Ambiental , Humanos , Lacase , Peroxidases , Praguicidas
13.
Proc Natl Acad Sci U S A ; 117(3): 1419-1428, 2020 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-31896585

RESUMO

By constructing an in vivo-assembled, catalytically proficient peroxidase, C45, we have recently demonstrated the catalytic potential of simple, de novo-designed heme proteins. Here, we show that C45's enzymatic activity extends to the efficient and stereoselective intermolecular transfer of carbenes to olefins, heterocycles, aldehydes, and amines. Not only is this a report of carbene transferase activity in a completely de novo protein, but also of enzyme-catalyzed ring expansion of aromatic heterocycles via carbene transfer by any enzyme.


Assuntos
Biocatálise , Proteínas de Escherichia coli/química , Metano/análogos & derivados , Peroxidases/química , Aldeídos/química , Alcenos/química , Aminas/química , Escherichia coli , Proteínas de Escherichia coli/metabolismo , Metano/química , Peroxidases/metabolismo , Especificidade por Substrato
14.
Environ Pollut ; 259: 113940, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31931415

RESUMO

Jicama peroxidase (JP) was covalently immobilized onto functionalized multi-walled carbon nanotube (MWCNT) Buckypaper/Polyvinyl alcohol (BP/PVA) membrane and employed for degradation of methylene blue dye. The parameters of the isotherm and kinetic models are estimating using ant colony optimization (ACO), which do not meddle the non-linearity form of the respective models. The proposed inverse modelling through ACO optimization was implemented, and the parameters were evaluated to minimize the non-linear error functions. The adsorption of MB dye onto JP-immobilized BP/PVA membrane follows Freundlich isotherm model (R2 = 0.99) and the pseudo 1st order or 2nd kinetic model (R2 = 0.980 & 0.968 respectively). The model predictions from the parameters estimated by ACO resulted values close the experimental values, thus inferring that this approach captured the inherent characteristics of MB adsorption. Moreover, the thermodynamic studies indicated that the adsorption was favourable, spontaneous, and exothermic in nature. The comprehensive structural analyses have confirmed the successful binding of peroxidase onto BP/PVA membrane, as well as the effective MB dye removal using immobilized JP membrane. Compared to BP/PVA membrane, the reusability test revealed that JP-immobilized BP/PVA membrane has better dye removal performances as it can retain 64% of its dye removal efficiency even after eight consecutive cycles. Therefore, the experimental results along with modelling results demonstrated that JP-immobilized BP/PVA membrane is expected to bring notable impacts for the development of effective green and sustainable wastewater treatment technologies.


Assuntos
Algoritmos , Azul de Metileno , Modelos Químicos , Álcool de Polivinil , Adsorção , Concentração de Íons de Hidrogênio , Cinética , Peroxidase , Peroxidases , Termodinâmica
15.
Food Microbiol ; 87: 103389, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31948630

RESUMO

To overcome the deleterious effects of hydrogen peroxide, Lactobacillus plantarum elicits an adaptive response to oxidative stress. In this study, global transcriptomic analysis revealed that L. plantarum CAUH2 expanded its carbon source utilizing profile and enhanced glycolysis to produce more ATP to confront with H2O2 stress. Some antioxidant enzymes including NADH peroxidase, thioredoxin reductase and glutathione peroxidase were 6.11, 36.76 and 6.23-fold up-regulated at transcription level for H2O2 scavenging. Meanwhile, free ferrous iron (Fe2+) was maintained at low concentrations in the cytoplasm, which could limit Fenton reaction and reduce the production of hydroxyl radicals. To repair DNA lesion caused by H2O2, both base excision repair system and recombinational DNA repair pathway were employed by L. plantarum CAUH2. In addition, the expression of methionine sulfoxide reductases and thioredoxin were up-regulated to repair oxidized proteins. It is noteworthy that some transcriptional regulators (Spx, CcpA and MarR1) were predicted to participate in the adaptive response to H2O2 stress, suggesting that L. plantarum CAUH2 utilized a wide array of sensors to monitor oxidative stress and modulated the transcriptional regulation network under H2O2 stress. These findings provide novel insight into the protective mechanisms developed by L. plantarum to cope with oxidative stress.


Assuntos
Proteínas de Bactérias/genética , Peróxido de Hidrogênio/farmacologia , Lactobacillus plantarum/efeitos dos fármacos , Lactobacillus plantarum/genética , Proteínas de Bactérias/metabolismo , Perfilação da Expressão Gênica , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Lactobacillus plantarum/enzimologia , Lactobacillus plantarum/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Peroxidases/genética , Peroxidases/metabolismo , Tiorredoxinas/genética , Tiorredoxinas/metabolismo , Transcriptoma/efeitos dos fármacos
16.
Chemosphere ; 243: 125318, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31995862

RESUMO

Increased agricultural intensification goes with the widespread use of herbicides that adversely affect aquatic biodiversity. The effects of herbicides on toxin-producing cyanobacteria have been poorly studied. The present study aimed to investigate the toxicological and physiological effects of the herbicide clethodim on Raphidiopsis raciborskii (a.k.a. Cylindrospermopsis raciborskii) ITEPA1 and Microcystis aeruginosa BCCUSP232. On day four of the experiment, the exposure to 25 mg/L clethodim resulted in the highest cell density of R. raciborskii. Similarly, exposure to the 1, 5, 20, and 50 mg/L clethodim treatments resulted in the highest cell densities of M. aeruginosa on day 4 of the experiment. Medium effect concentrations (EC50) after 96 h of exposure of both strains to clethodim were 192.98 mg/L and 168.73 mg/L for R. raciborskii and M. aeruginosa, respectively. The presence of clethodim significantly increased the total microcystin content of M. aeruginosa compared to the control cultures. At 400 mg/L, total saxitoxins content of R. raciborskii was 27% higher than that of the control cultures on day 4. In contrast, cultures exposed to 100 mg/L clethodim had the lowest saxitoxins levels per cell quota. There was an increase in the levels of intracellular hydrogen peroxide in both species during exposure to clethodim, which was followed by significant changes (p < 0.05) in the activity of antioxidant enzymes such as peroxidase and superoxide dismutase. These results revealed that the presence of low levels of clethodim in the aquatic environment might lead to the excessive proliferation of cyanobacteria and alteration of their cyanotoxins content.


Assuntos
Cicloexanonas/farmacologia , Cylindrospermopsis/efeitos dos fármacos , Cylindrospermopsis/crescimento & desenvolvimento , Microcystis/efeitos dos fármacos , Microcystis/crescimento & desenvolvimento , Antioxidantes/metabolismo , Toxinas Bacterianas/metabolismo , Cylindrospermopsis/metabolismo , Herbicidas/farmacologia , Microcistinas/metabolismo , Microcystis/metabolismo , Peroxidases/metabolismo , Saxitoxina/metabolismo , Superóxido Dismutase/metabolismo , Poluentes Químicos da Água/farmacologia
17.
Chemosphere ; 242: 125112, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31669993

RESUMO

This investigation was made to examine the role of indole-3-acetic acid (IAA), gibberellin A3 (GA3), 6-Benzylaminopurine (6-BA), and 24-epibrassinolide (EBL) in improving stress tolerance and phytoremediation of the cadmium (Cd) and uranium (U) by mustard (Brassica juncea L.). The optimum concentrations of IAA, GA3, 6-BA, and EBL were determined based on plant biomass production, metal uptake, translocation, and removal efficiency. The biomass and total chlorophyll content decreased under Cd and U stress. Nevertheless, the application of IAA, GA3, and 6-BA significantly (p < 0.05) increased the growth and total chlorophyll content of mustard. The malondialdehyde (MDA) and H2O2 content of mustard were enhanced under Cd and U stress, but they were significantly (p < 0.05) decreased in plant growth regulators (PGRs) treatments (except for EBL). PGRs treatments increased activities of antioxidant enzymes such as superoxide dismutase, peroxidase, catalase, and ascorbate peroxidase, thus reducing the oxidative stress. Furthermore, the shoot uptake of Cd and U of IAA and EBL treatments was significantly (p < 0.05) higher than that of other treatments. IAA and EBL also have more significant effects on the translocation and remediation of Cd and U compared to GA3 and 6-BA. The removal efficiency of Cd and U reached the maximum in the 500 mg L-1 IAA treatment, which was 330.77% and 118.61% greater than that in the control (CK), respectively. These results suggested that PGRs could improve the stress tolerance and efficiency of phytoremediation using B. juncea in Cd- and U- contaminated soils.


Assuntos
Biodegradação Ambiental , Cádmio/metabolismo , Mostardeira/metabolismo , Reguladores de Crescimento de Planta , Poluentes do Solo/metabolismo , Urânio/metabolismo , Antioxidantes , Ascorbato Peroxidases , Brassinosteroides , Cádmio/análise , Catalase , Peróxido de Hidrogênio , Malondialdeído , Peroxidase , Peroxidases , Solo , Poluentes do Solo/análise , Esteroides Heterocíclicos , Superóxido Dismutase
18.
Chemosphere ; 242: 125117, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31655399

RESUMO

Amino-aromatic compounds, 2-amino-4-nitrotoluene (ANT), and 2,4-diaminotoluene (DAT) are carcinogens and environmentally persistent pollutants. In this study, we investigated their degradation by natural manganese peroxidase (nMnP) derived from Phanerochaete chrysosporium and recombinant manganese peroxidase packaged in vaults (vMnP). Encapsulation of manganese peroxidase (MnP) in ribonucleoprotein nanoparticle cages, called vaults, was achieved by creating recombinant vaults in yeast Pichia pastoris. Vault packaging increased the stability of MnP by locally sequestering multiple copies of the enzyme. Within 96  h, both vMnP and nMnP catalyzed over 72% removal of ANT in-vitro, which indicates that vault packaging did not limit substrate diffusion. It was observed that vMnP was more efficient than nMnP and P. chrysosporium for the catalysis of target contaminants. Only 57% of ANT was degraded by P. chrysosporium even when MnP activity reached about 480 U L-1 in cultures. At 1.5 U L-1 initial activity, vMnP achieved 38% of ANT and 51% of DAT degradation, whereas even 2.7 times higher activity of nMnP showed insignificant biodegradation of both compounds. These results imply that due to protection by vault cages, vMnP has lower inactivation rates. Thus, it works effectively at lower dosage for a longer duration compared to nMnP without requiring frequent replenishment. Collectively, these results indicate that fungal enzymes packaged in vault nanoparticles are more stable and active, and they would be effective in biodegradation of energetic compounds in industrial processes, waste treatment, and contaminated environments.


Assuntos
Biodegradação Ambiental , Poluentes Ambientais/metabolismo , Nanopartículas/química , Compostos Orgânicos/metabolismo , Peroxidases , Phanerochaete/metabolismo
19.
J Environ Manage ; 256: 109908, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31822458

RESUMO

Phenolics drive the global economy, but they also pose threats to soil health and plant growth. Enzymes like peroxidase have the potential to remove the phenolic contaminants from the wastewater; however, their role in restoring soil health and improving plant growth has not yet been ascertained. We fractionated efficient peroxidases (MPx) from leaves of an invasive species of Mesquite, Prosopis juliflora, and demonstrated its superiority over horseradish peroxidase (HRP) in remediating phenol, 3-chlorophenol (3-CP), and a mixture of chlorophenols (CP-M), from contaminated soil. MPx removes phenolics over a broader range of pH (2.0-9.0) as compared with HRP (pH: 7.0-8.0). In soil, replacing H2O2 with CaO2 further increases the phenolic removal efficiency of MPx (≥90% of phenol, ≥ 70% of 3-CP, and ≥90% of CP-M). MPx maintains ~4-fold higher phenolic removal efficiency than purified HRP even in soils with extremely high contaminant concentration (2 g phenolics/kg of soil), which is desirable for environmental applications of enzymes for remediation. MPx treatment restores soil biological processes as evident by key enzymes of soil fertility viz. Acid- and alkaline-phosphatases, urease, and soil dehydrogenase, and improves potential biochemical fertility index of soil contaminated with phenolics. MPx treatment also assists the Vigna mungo test plant to overcome toxicant stress and grow healthy in contaminated soils. Optimization of MPx for application in the field environment would help both in the restoration of phenolic-contaminated soils and the management of invasive Mesquite.


Assuntos
Prosopis , Poluentes do Solo , Biodegradação Ambiental , Peróxido de Hidrogênio , Espécies Introduzidas , Peroxidases , Fenóis , Solo
20.
Chemosphere ; 244: 125510, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31837562

RESUMO

As a result of the use of a large amount of salt in dye industries, azo dye decolorization is often needed under hypersaline environments and low dissolved oxygen. Consortium GG-1, which is able to decolorize azo dyes in high salt concentrations and microaerophilic conditions, can be enriched using Metanil Yellow. Consortium GG-1 is mainly composed of Zobellella (62.25%), Rheinheimera (12.4%) and Marinobacterium (9.44%) and is able to decolorize azo dyes under 1%-10% salinity. The activities of azoreductase, laccase and lignin peroxidase were also measured. Together with the detected intermediates and the results obtained from FTIR, the decolorization process of Metanil Yellow was proposed. The influences of pH, initial concentration of azo dyes and concentration of yeast extract on the decolorization rate were also detected. Meanwhile, consortium GG-1 was identified with wide substrate specificity to dyes such as Direct Blue B, Acid Black ATT, and Acid Violet 7. Therefore, consortium GG-1 was identified with potential use in azo dye elimination.


Assuntos
Compostos Azo/metabolismo , Biodegradação Ambiental , Cor , Corantes , Lacase , NADH NADPH Oxirredutases/metabolismo , Naftalenossulfonatos/metabolismo , Peroxidases/metabolismo
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