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1.
Ecotoxicol Environ Saf ; 284: 117039, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-39270417

RESUMO

AIM: The present work explored the mechanism of dimethyl phthalate (DMP, the environmental contaminant) exposure in inducing cognitive impairment. METHODS: Targets and regulatory networks related to DMP-brain injury-cognitive impairment were analyzed through network pharmacology. DMP exposure was carried out to simulate DMP environmental uptake, whereas Morris water maze was performed for examining cognitive impairment. Additionally, inflammatory cytokine levels within tissues were measured. hematoxylin-eosin staining(H&E) and Nissl staining was conducted to examine brain tissue injury, while Western blot was carried out for identifying protein levels. After applying.Small interfering RNA(siRNA-COX2) and celecoxib-COX2 inhibitors separately, we analyzed impacts of DMP. Besides, in vitro experiments were performed to analyze impacts of DMP on microglial activation. RESULTS: As suggested by network pharmacology,Cyclooxygenase-2-PTGS2 (COX2) showed significant relation to DMP, and it exerted its effect via COX2. Following DMP exposure, mice experienced obvious cognitive impairment and brain damage, besides, microglial cells were activated, and inflammatory cytokines were up-regulated. Applying siRNA-COX2 and celecoxib-COX2 suppressed DMP's impact and mitigated mouse cognitive impairment. Based on in vitro analysis, DMP led to microglial activation and neuroinflammation. CONCLUSION: DMP exposure causes neuroinflammation via the COX2-regulated microglial activation, thus leading to cognitive impairment. COX2 may serve as the key action target of DMP.


Assuntos
Disfunção Cognitiva , Ciclo-Oxigenase 2 , Doenças Neuroinflamatórias , Ácidos Ftálicos , Animais , Disfunção Cognitiva/induzido quimicamente , Camundongos , Ciclo-Oxigenase 2/metabolismo , Ciclo-Oxigenase 2/genética , Ácidos Ftálicos/toxicidade , Doenças Neuroinflamatórias/induzido quimicamente , Masculino , Microglia/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Camundongos Endogâmicos C57BL
2.
Environ Sci Technol ; 57(17): 6876-6887, 2023 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-37083356

RESUMO

Plastics-microorganism interactions have aroused growing environmental and ecological concerns. However, previous studies concentrated mainly on the direct interactions and paid little attention to the ecotoxicology effects of phthalates (PAEs), a common plastic additive that is continuously released and accumulates in the environment. Here, we provide insights into the impacts of PAEs on the dissemination of antibiotic resistance genes (ARGs) among environmental microorganisms. Dimethyl phthalate (DMP, a model PAE) at environmentally relevant concentrations (2-50 µg/L) significantly boosted the plasmid-mediated conjugation transfer of ARGs among intrageneric, intergeneric, and wastewater microbiota by up to 3.82, 4.96, and 4.77 times, respectively. The experimental and molecular dynamics simulation results unveil a strong interaction between the DMP molecules and phosphatidylcholine bilayer of the cell membrane, which lowers the membrane lipid fluidity and increases the membrane permeability to favor transfer of ARGs. In addition, the increased reactive oxygen species generation and conjugation-associated gene overexpression under DMP stress also contribute to the increased gene transfer. This study provides fundamental knowledge of the PAE-bacteria interactions to broaden our understanding of the environmental and ecological risks of plastics, especially in niches with colonized microbes, and to guide the control of ARG environmental spreading.


Assuntos
Antibacterianos , Bactérias , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/genética , Bactérias/genética , Genes Bacterianos , Plásticos , Transferência Genética Horizontal
3.
J Environ Manage ; 301: 113885, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34619592

RESUMO

Cold plasma based treatment of contaminated water is becoming a promising novel green remediation option. This study assessed the performance of two different cold plasma reactors, using, respectively, a self-pulsing discharge (SPD) and a multipin corona discharge (MCD), in the degradation of dimethyl phthalate (DMP), a persistent and ubiquitous pollutant of the aquatic environment. The process kinetics and energy efficiency, as well as the main plasma generated reactive species were determined under various operating conditions concerning the plasma feed gas and flowrate, the voltage polarity, the input power, the DMP initial concentration, the liquid conductivity, and the aqueous matrix used to prepare DMP solutions for these experiments. The MCD reactor, operated with air as plasma feed gas and negative voltage polarity, gave the best results in terms of rate and energy efficiency. Moreover, variations in plasma input power and in the liquid conductivity have limited effect on DMP degradation rate, making this reactor suitable for treating liquids with a range of initial conductivities The effects of DMP initial concentration on its rate of degradation and on the process energy efficiency were also investigated. Differences in the efficiency of production and distribution of plasma generated reactive species, notably •OH and H2O2, observed for the two tested reactors are discussed in terms of different extension of the plasma/liquid interface and diffusion into the bulk solution. It is proposed that among the reactive species, •OH foremost, and O3 to a lesser extent, play a pivotal role in DMP degradation, while the contribution of H2O2 appears to be limited. The rate of DMP degradation was not drastically different in Milli-Q water and in tap water, a positive outcome in view of practical applications of the technology. The lower rate observed in tap than in Milli-Q water is attributed to the presence of bicarbonate and carbonate, which are known scavengers of hydroxyl radicals.


Assuntos
Ácidos Ftálicos , Poluentes Químicos da Água , Peróxido de Hidrogênio , Cinética , Água
4.
J Appl Microbiol ; 131(3): 1274-1288, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33599367

RESUMO

AIM: The objectives of the present study were to explore the benzyl butyl phthalate (BBP) and dimethyl phthalate (DMP) degradation potential of Bacillus marisflavi RR014 isolated from the tap water of public toilet and also to optimize the phthalates degradation process using response surface methodology. METHODS AND RESULTS: The minimal salt medium was used for the biodegradation analysis of phthalates. The quantification of phthalates and their intermediate metabolites identification were done by using UHPLC and LC-MS/MS respectively. The results revealed that B. marisflavi RR014 is capable of degrading both the phthalates under varying pH, temperature and salinity conditions. The formation of phthalic acid from the breakdown of BBP and DMP (500 mg l-1 ) in the medium was observed after 24 h. After 72 h, 61% of BBP and 98·9% of DMP in the medium was degraded as monitored by UHPLC. The identification of intermediate metabolites by LC-MS/MS revealed that hydrolysis of BBP and DMP produces phthalic acid. CONCLUSIONS: The degradation rate of both the phthalates was increased as the parameters increased up to an optimum level. The three environmental factors (pH, temperature and salt concentration) strongly affect the rate of degradation of both the phthalates. The maximum degradation rate for both the phthalates was achieved at pH 7, temperature 35°C and salt concentration of 1% as observed from the central composite experimental design. SIGNIFICANCE AND IMPACT OF THE STUDY: It is the first report on the phthalates biodegradation potential of B. marisflavi RR014 isolated from the tap water of public toilet. The bacterium is capable of degrading BBP and DMP under varying pH, temperature and salinity, therefore, ideal to treat the phthalate contaminated environments.


Assuntos
Bacillus/metabolismo , Biodegradação Ambiental , Disruptores Endócrinos , Ácidos Ftálicos , Cromatografia Líquida , Disruptores Endócrinos/metabolismo , Ácidos Ftálicos/metabolismo , Espectrometria de Massas em Tandem , Microbiologia da Água
5.
J Environ Sci (China) ; 107: 171-183, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34412780

RESUMO

Dimethyl phthalate (DMP), used as a plasticizer in industrial products, exists widely in air, water and soil. Staphylococcus aureus is a typical model organism representing Gram-positive bacteria. The molecular mechanisms of DMP toxicology in S. aureus were researched by proteomic and transcriptomic analyses. The results showed that the cell wall, membrane and cell surface characteristics were damaged and the growth was inhibited in S. aureus by DMP. Oxidative stress was induced by DMP in S. aureus. The activities of succinic dehydrogenase (SDH) and ATPase were changed by DMP, which could impact energy metabolism. Based on proteomic and transcriptomic analyses, the oxidative phosphorylation pathway was enhanced and the glycolysis/gluconeogenesis and pentose phosphate pathways were inhibited in S. aureus exposed to DMP. The results of real-time reverse transcription quantitative PCR (RT-qPCR) further confirmed the results of the proteomic and transcriptomic analyses. Lactic acid, pyruvic acid and glucose were reduced by DMP in S. aureus, which suggested that DMP could inhibit energy metabolism. The results indicated that DMP damaged the cell wall and membrane, induced oxidative stress, and inhibited energy metabolism and activation in S. aureus.


Assuntos
Proteômica , Staphylococcus aureus , Metabolismo Energético , Estresse Oxidativo , Ácidos Ftálicos
6.
Environ Res ; 188: 109660, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32502684

RESUMO

In this study, the main influence factors of combined UV/O3 process in practical industrial application were explored through laboratory trials and industrial pilot tests. Dimethyl phthalate (DMP) was analyzed as the research subject through different experiments in laboratory. The degradation effect of organic compounds by O3 and UV/O3 processes in different air distribution methods was compared independently, and the mechanism of free radical generation by the two processes was analyzed. This study found that the combined UV/O3 process for organic matter mineralization is clearly better than that of independent effect of O3 process as mixed gas-liquid distribution method was superior to the bubble aeration method. The experimental conditions included inlet O3 concentration between 70 and 75 mg/L, reactor internal relative pressure at 0.3 MPa, contact reaction time of 12 min, DMP mineralization efficiency reaching 63.07%. The calculated dosing ratio of O3 in the dynamic experiment was around 0.74 mg CODCr/mg O3. The results showed that the best effect in wastewater treatment was achieved when the conditions of ultraviolet lamp irradiation intensity and the O3 dosage reached 822.88 W/m2 15 mg/L and utilized in conjunction with biochemical reactions. The resulting CODCr concentration of effluent reached 39.8 mg/L. Finally, it is determined that the main influence factors affecting the economically efficient operation of UV/O3 process were the efficient O3 distribution mode, control of the relative pressure within the reactor, proportion of ozone addition and light source configuration.


Assuntos
Ozônio , Poluentes Químicos da Água , Purificação da Água , Oxirredução , Raios Ultravioleta , Eliminação de Resíduos Líquidos , Águas Residuárias/análise
7.
Ecotoxicol Environ Saf ; 205: 111169, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32827961

RESUMO

The characteristics and content of organo-mineral complex were confirmed to be changed in agriculture soils under the biochar application with long-term, but the resulting environmental effects in the retention and lasting of agrochemicals and xenobiotic pollutants is far from clear. In this study, biochar-soil composites were prepared by one-step dry ball-milling method, and a sorption case study was proceed to investigate the biochar incorporated affection in soils on the transport of dimethyl phthalate (DMP). More surface oxygen-containing functional groups on ball-milled biochar enhanced its complexation with soil minerals. Sorption isotherms of DMP onto the biochar-soil composites were well described by the Freundlich model, both heterogeneous surface and multilayer interactions occurred simultaneously. The kinetics of sorption could be simulated with the pseudo-second-order model (R2 > 0.98), while the average sorption energy (Ea) calculated from Dubinin-Radushkevich isotherms were found in the range of 3.83-5.60 kJ mol-1, which revealed that the sorption processes coexist of chemisorption and physisorption, and π-π electron donor-acceptor interaction, pore-filling and hydrophobic interactions could be identified as the main sorption mechanisms. Desorption of absorbed DMP appeared obvious nonlinear characteristics and lag effect, the calculated hysteresis index (HI) increased with the application of biochar into soil. Considering the phenomenon of biochar aging and soil complexation, it is important to verify how the transport and natural attenuation of contaminant will be influenced by biochar addition, especially the long-term effect in soil ecosystem.


Assuntos
Carvão Vegetal/química , Ácidos Ftálicos/análise , Poluentes do Solo/análise , Solo/química , Adsorção , Agricultura , Ecossistema , Ésteres , Cinética , Modelos Teóricos , Propriedades de Superfície
8.
Mikrochim Acta ; 187(2): 118, 2020 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-31925542

RESUMO

A CuCr-layered double hydroxide nanosheet intercalated with terephthalic acid (TPA/LDH) was introduced as a coating for the in-tube solid phase microextraction (IT-SPME). The coating was placed on the inner surface of a stainless steel tube by using two-electrode electrodeposition. The sorbent was characterized by X-ray diffraction, scanning electronic microscopy, and Fourier transform infrared spectroscopy. The TPA/LDH coating, compared to a nitrate-LDH coating, exhibits enhanced extraction efficiency, long lifetime, good mechanical stability, and a large specific surface. The method was used for the extraction, preconcentration, and subsequent HPLC-based determination of dimethyl phthalate (DMP), dibutyl phthalate (DBP), diallyl phthalate (DAP), and diethylhexyl phthalate (DEHP). The effects of pH value of the solution, salt concentration, extraction and desorption conditions, and the effect of the alcohol content of the solution on the extraction efficiency were optimized. Under optimal conditions, the response is linear in the 0.05 to 1000 µg L-1 ester concentration range, and the limits of detection (at S/N = 3) range between 0.01 to 0.1 µg L-1. The inter- and intra-assay precisions (RSD%, for n = 3) range from 3.8 to 6.8% and from 3.5 to 5.7%, respectively. The method was successfully applied to the determination of four phthalate esters in different beverage samples. Graphical abstractA CuCr-layered double hydroxide nanosheet intercalated with terephthalic acid was used as a coating for in-tube solid phase microextraction of some phthalate esters from beverage samples.

9.
J Environ Manage ; 270: 110863, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32501242

RESUMO

In the present study, ozone was applied for the removal of dimethyl phthalate (DMP) from soil. The effect of several experimental parameters was investigated considering, the initial DMP concentration, ozone flow, the type of soil (sand and agricultural soil) and the presence of α-FeOOH as a potential catalyst in the reaction system with sand. The elimination of DMP using ozone is significantly affected by the type of soil. In the case of sand, conventional ozonation was capable to degrade 74% of the initial DMP concentration (0.5 mg g-1) after 8 h of the reaction, however, the mineralization degree was below 50%. Under the same experimental conditions, the complete elimination of DMP was achieved when calcined agricultural soil was present reaching a 70% of mineralization. The presence of metal oxides in calcined agricultural soil combined with ozone produced oxidants species which were responsible of incrementing the mineralization degree (around 20% in comparison with the sand). The toxicity tests on lettuce seed demonstrated lower toxicity of DMP byproducts after ozonation. The DMP high removal efficiencies and the lower toxicity of generated byproducts in soil prove the applicability of ozone treatment for soil remediation.


Assuntos
Ozônio , Ácidos Ftálicos , Poluentes Químicos da Água , Solo
10.
Molecules ; 25(3)2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32023918

RESUMO

A composite flocculant P(AM-DMDAAC) was synthesized by the copolymerization of acrylamide (AM) and dimethyl diallyl ammonium chloride (DMDAAC). By using microwave (MV) assistance with ammonium persulfate as initiator, the synthesis had a short reaction time and yielded a product with good solubility. Fourier-transform infrared spectroscopy, scanning electron microscopy, and differential thermal analysis-thermogravimetric analysis were employed to determine the structure and morphology of P(AM-DMDAAC). The parameters affecting the intrinsic viscosity of P(AM-DMDAAC), such as MV time, mass ratio of DMDAAC to AM, bath time, reaction temperature, pH value, and the dosages of ammonium persulfate initiator, EDTA, sodium benzoate, and urea were examined. Results showed that the optimum synthesis conditions were MV time of 1.5 min, m(DMDAAC):m(AM) of 4:16, 0.5 wt‱ initiator, 0.4 wt‱ EDTA, 0.3 wt‱ sodium benzoate, 2 wt‱ urea, 4 h bath time, reaction temperature of 40 °C, and pH of 2. The optimal dimethyl phthalate (DMP) removal rate can reach 96.9% by using P(AM-DMDAAC), and the P(AM-DMDAAC) had better flocculation than PAM, PAC, and PFS.


Assuntos
Resinas Acrílicas/química , Dimetilaminas/química , Ácidos Ftálicos/química , Sulfato de Amônio/química , Floculação , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Varredura , Micro-Ondas , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura
11.
Ecotoxicol Environ Saf ; 180: 208-214, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31096126

RESUMO

Dimethyl phthalate (DMP), a phthalate ester (PAE), is a ubiquitous and organic pollutant. In this study, the toxicity of DMP to Escherichia coli K12 and its underlying mechanism were investigated. The results showed that DMP inhibited the growth of E. coli K12 and induced cell inactivation and/or death. DMP caused serious damage to the cell membrane of E. coli K12, and the damage increased with higher DMP concentrations. DMP exposure disrupted cell membranes, as evidenced by dose-dependent variations of cell structures, surface properties, and membrane compositions. Increases in the malondialdehyde (MDA) content indicated an increase in oxidative stress induced by DMP in E. coli K12. The activity of succinic dehydrogenase (SDH) was changed by DMP, which could affect energy metabolism in the membrane of E. coli K12. The expression levels of OmpA and OmpX were increased, and the expression levels of OmpF and OmpW were decreased, in E. coli K12 exposed to DMP. The toxicities of DMP to E. coli K12 could be ascribed to membrane disruption and oxidative stress-induced cell inactivation and/or death. The outcomes will shed new light on the assessment of the ecological effects of DMP.


Assuntos
Poluentes Ambientais/toxicidade , Escherichia coli K12/efeitos dos fármacos , Ácidos Ftálicos/toxicidade , Proteínas da Membrana Bacteriana Externa/metabolismo , Membrana Celular/efeitos dos fármacos , Escherichia coli K12/metabolismo , Malondialdeído/análise , Estresse Oxidativo
12.
Toxicol Mech Methods ; 29(1): 60-66, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30113263

RESUMO

Phthalates are used as plasticizers in a wide range of products and are known to affect the human health adversely. Hence, the present study was carried out to identify and quantify the presence of four phthalates namely dimethyl phthalate (DMP), dibutyl phthalate (DBP), and diethyl phthalate (DEP), di (2-ethylhexyl) phthalate (DEHP) in the two baby products i.e. baby oils and baby lotions. The daily exposure levels and hazard index of each phthalate were also calculated. It was an analytical study where two different brands of samples of baby oil and baby lotion each, from the date of manufacturing of 3, 10, and 20 months were collected. The extraction of phthalates from different samples was done and analyzed using HPTLC. Results showed the presence of all four phthalates, although some phthalates were not present in 3 M samples. The maximum concentration of all the phthalates was found in 20 M samples. Their concentration increased with the storage time indicating the possibility of leaching and migration of phthalates from the container into the product. The hazard indices for phthalates estimated for baby oil and baby lotion were found below 1, which denotes that the daily phthalate exposures are within the regulatory limits. It is important to consider that the exposure to phthalates can occur not only by dermal contact of these baby products but also through other routes. Hence, the study signifies the importance of phthalates concentration in such regularly used products.


Assuntos
Cosméticos/química , Dibutilftalato/análise , Dietilexilftalato/análise , Ácidos Ftálicos/análise , Cromatografia Líquida de Alta Pressão , Cosméticos/normas , Exposição Ambiental/análise , Humanos , Lactente , Recém-Nascido , Limite de Detecção , Embalagem de Produtos/normas , Medição de Risco , Emirados Árabes Unidos
13.
Artigo em Inglês | MEDLINE | ID: mdl-29473786

RESUMO

To enable further study and assessment of indoor inhalation exposure risk, an online apparatus enabling measurement of semi-volatile compound partitioning on household particulates was developed. An example for use of the apparatus is described using dimethyl phthalate (DMP). The system employs direct measurement by membrane introduction mass spectrometry (MIMS). The MIMS system was calibrated using known gas phase DMP concentrations produced by gravimetrically calibrated permeation devices. The quantity of DMP sorbed by particles is described first using a model particle type, a reverse-phase liquid chromatography packing material, and then with a household dust sample. In addition, the desorption of semi-volatile compounds from a household dust sample was monitored using the apparatus, and characteristic fragment ion signals for phthalate compounds were observed.


Assuntos
Poluição do Ar em Ambientes Fechados/análise , Poeira/análise , Espectrometria de Massas/métodos , Sistemas On-Line , Material Particulado/análise , Ácidos Ftálicos/análise , Adsorção , Calibragem , Cromatografia Gasosa-Espectrometria de Massas/métodos , Cromatografia Gasosa-Espectrometria de Massas/normas , Humanos , Espectrometria de Massas/normas , Sistemas On-Line/instrumentação , Sistemas On-Line/normas , Material Particulado/farmacocinética , Ácidos Ftálicos/farmacocinética
14.
Biodegradation ; 28(5-6): 413-421, 2017 12.
Artigo em Inglês | MEDLINE | ID: mdl-28836032

RESUMO

The aerobic biodegradation of dimethyl phthalate (DMP) is initiated with two hydrolysis reactions that generate an intermediate, phthalic acid (PA), that is further biodegraded through a two-step di-oxygenation reaction. DMP biodegradation is inhibited when PA accumulates, but DMP's biodegradation can be enhanced by adding an exogenous electron donor. We evaluated the effect of adding succinate, acetate, or formate as an exogenous electron donor. PA removal rates were increased by 15 and 30% for initial PA concentrations of 0.3 and 0.6 mM when 0.15 and 0.30 mM succinate, respectively, were added as exogenous electron donor. The same electron-equivalent additions of acetate and formate had the same acceleration impacts on PA removal. Consequently, the DMP-removal rate, even PA coexisting with DMP simultaneously, was accelerated by 37% by simultaneous addition of 0.3 mM succinate. Thus, lowering the accumulation of PA by addition of an electron increased the rate of DMP biodegradation.


Assuntos
Bactérias/metabolismo , Oxigênio/metabolismo , Ácidos Ftálicos/metabolismo , Aerobiose , Bactérias/química , Biodegradação Ambiental , Reatores Biológicos/microbiologia , Cinética , Oxigênio/química , Ácidos Ftálicos/química , Esgotos/química , Esgotos/microbiologia , Succinatos/química , Succinatos/metabolismo
15.
J Basic Microbiol ; 57(11): 941-949, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28833312

RESUMO

A Comamonas testosterone bacterial strain, named as DB-7, capable of utilizing dimethyl phthalate (DMP) as sole carbon source and energy for growth was isolated from soil with plastic film mulching by an enrichment culture technique. This bacterium was identified as C. testosterone by 16S rRNA sequence analysis and phospholipid fatty acid profile. DB-7 could degrade more than 99% of 450 mg L-1 DMP within 14 hours, and degraded DMP of different concentrations rapidly. The optimal degradation temperature and pH were 30-35 °C and pH 9.0, respectively. The degradation rate of DMP was positively related to inoculum volume of the bacterium. The result of HPLC and LC/MS analysis of metabolic products indicated that the major degrading intermediates were mono-methyl phthalate (MMP) and phthalic acid (PA) during the degradation of DMP by DB-7. Partial sequences of three genes involved in PA metabolism were detected in DB-7, and the expression of phthalate 4, 5-dioxygenase was drastically induced in the presence of DMP and PA. DB-7 is promising to be applied to DMP bioremediation because of its high degrading efficiency.


Assuntos
Biodegradação Ambiental , Comamonas testosteroni/isolamento & purificação , Comamonas testosteroni/metabolismo , Ácidos Ftálicos/metabolismo , Microbiologia do Solo , Comamonas , Comamonas testosteroni/genética , Comamonas testosteroni/crescimento & desenvolvimento , Ácidos Graxos , Genes Bacterianos/genética , Concentração de Íons de Hidrogênio , Metabolismo/genética , Oxigenases/genética , Oxigenases/metabolismo , RNA Ribossômico 16S/genética , Análise de Sequência , Temperatura , Fatores de Tempo
16.
J Environ Manage ; 184(Pt 2): 281-288, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27729177

RESUMO

Dimethyl phthalate (DMP) as one of the most important and extensively used Phthalic acid esters (PAEs) is known to likely cause dysfunctions of the endocrine systems, liver, and nervous systems of animals. In this paper, the degradation and behavior of DMP were investigated in a laboratory scale anaerobic/anoxic/oxic (AAO) treatment system. In addition, a degradation model including biodegradation and sorption was formulated so as to evaluate the fate of DMP in the treatment system, and a mass balance model was designed to determine kinetic parameters of the removal model. The study indicated that the optimal operation condition of HRT and SRT for DMP and nutrients removal were 18 h and 15 d respectively, and the degradation rates of anaerobic, anoxic and aerobic zones for DMP were 13.4%, 13.0% and 67.7%, respectively. Under the optimal conditions, the degraded DMP was 73.8%, the released DMP in the effluent was 5.8%, the accumulated DMP was 19.3%, and the remained DMP in the waste sludge was 1.1%. Moreover, the degradation process of DMP by acclimated activated sludge was in accordance with the first-order kinetics equation. The model can be used for accurately modeling the degradation and behavior of DMP in the AAO system.


Assuntos
Ácidos Ftálicos/metabolismo , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/metabolismo , Biodegradação Ambiental , Cinética , Modelos Teóricos , Ácidos Ftálicos/química , Esgotos , Eliminação de Resíduos Líquidos/instrumentação , Poluentes Químicos da Água/química
17.
J Environ Sci Health B ; 51(8): 553-7, 2016 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-27166703

RESUMO

Dimethyl phthalate (DMP), a typical phthalic acid ester, is widespread in the environment and causes extensive concern due to its adverse effects on human health. To understand the genotoxicity of DMP at molecular level, the toxic interaction of DMP with herring sperm (hs) deoxyribonucleic acid (DNA; hs-DNA) was investigated in vitro under simulated physiological conditions using multi-spectroscopic techniques and a molecular modeling method. The results of Ultraviolet-Visible absorption spectroscopy, fluorescence emission spectroscopy, and circular dichroism spectra indicated that DMP interacts with hs-DNA in a groove-binding mode that changes the double helical structure of DNA. The binding constant and the number of binding sites calculated from the fluorescence quenching data were 565.718 L mol(-1) and 0.7872, respectively. A molecular modeling study revealed that DMP tends to bind with DNA in the A-T-rich regions of minor groove and that hydrogen bonding and van der Waals forces play main roles in the interaction. This research can help to elucidate the mechanism of DMP toxicity in vivo.


Assuntos
DNA/efeitos dos fármacos , Peixes/crescimento & desenvolvimento , Ácidos Ftálicos/química , Ácidos Ftálicos/toxicidade , Espermatozoides/efeitos dos fármacos , Espermatozoides/crescimento & desenvolvimento , Animais , Sítios de Ligação/efeitos dos fármacos , Dicroísmo Circular , Fluorescência , Humanos , Ligação de Hidrogênio/efeitos dos fármacos , Masculino , Modelos Moleculares , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta , Termodinâmica
18.
Biodegradation ; 26(6): 431-41, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26342301

RESUMO

Dimethyl phthalate (DMP), an important industrial raw material, is an endocrine disruptor of concern for human and environmental health. DMP exhibits slow biodegradation, and its coupled treatment by means of advanced oxidation may enhance its biotransformation and mineralization. We evaluated two ways of coupling UV-H2O2 advanced oxidation to biodegradation: sequential coupling and intimate coupling in an internal circulation baffled biofilm reactor (ICBBR). During sequential coupling, UV-H2O2 pretreatment generated carboxylic acids that depressed the pH, and subsequent biodegradation generated phthalic acid; both factors inhibited DMP biodegradation. During intimately coupled UV-H2O2 with biodegradation, carboxylic acids and phthalic acid (PA) did not accumulate, and the biodegradation rate was 13 % faster than with biodegradation alone and 78 % faster than with biodegradation after UV-H2O2 pretreatment. Similarly, DMP oxidation with intimate coupling increased by 5 and 39 %, respectively, compared with biodegradation alone and sequential coupling. The enhancement effects during intimate coupling can be attributed to the rapid catabolism of carboxylic acids, which generated intracellular electron carriers that directly accelerated di-oxygenation of PA and relieved the inhibition effect of PA and low pH. Thus, intimate coupling optimized the impacts of energy input from UV irradiation used together with biodegradation.


Assuntos
Bactérias/metabolismo , Peróxido de Hidrogênio/farmacologia , Ácidos Ftálicos/metabolismo , Bactérias/efeitos dos fármacos , Bactérias/efeitos da radiação , Biodegradação Ambiental/efeitos dos fármacos , Biodegradação Ambiental/efeitos da radiação , Biotransformação , Disruptores Endócrinos/metabolismo , Oxirredução/efeitos dos fármacos , Oxirredução/efeitos da radiação , Esgotos/microbiologia , Raios Ultravioleta
19.
J Environ Sci Health B ; 50(4): 275-84, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25714459

RESUMO

After the "plasticizer event" in Taiwan, phthalic acid esters (PAEs) have been listed in "Inedible materials possibly added into food illegally" and "Commonly abused food additives." As one of the PAEs family, DMP has long been a problem of great concern due to its potential impacts on human health. In order to detect DMP with high sensitivity and specificity, a sensitive indirect competitive biotin-streptavidin enzyme-linked immunosorbent assay (BA-ELISA) has been established in this study. A high-titer rabbit polyclonal antibody (pAb-DMP) targeting DMP was obtained, and the procedures of BA-ELISA were optimized for the determination of DMP in milk and milk products. Under optimal conditions, good linearity was achieved within a range of 0.024 to 6.027 µg L(-1), with low cross-reactivity values for DMP structural analogues (lower than 10%). The median inhibitory concentration (IC50) was 0.356 µg L(-1) and the limit of detection (LOD) was 0.0082 µg L(-1). Finally, the concentrations of DMP in milk and milk products ranged from 1.03 µg kg(-1) to 7.23 µg kg(-1) by BA-ELISA. Satisfactory recoveries (90.26-112.38%) and coefficient of variation (CV) values (5.08-8.46%) were obtained. These results were consistent with those using gas chromatography-mass spectrometry (GC-MS), which further confirmed that the proposed BA-ELISA was accurate, specific, reliable and rapid for routine monitoring trace DMP residues in foodstuff, especially milk and milk products.


Assuntos
Laticínios/análise , Poluentes Ambientais/análise , Ensaio de Imunoadsorção Enzimática , Inocuidade dos Alimentos/métodos , Leite/química , Ácidos Ftálicos/análise , Animais , Queijo/análise , Monitoramento Ambiental , Contaminação de Alimentos/análise
20.
Sci Total Environ ; 926: 171902, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38521262

RESUMO

Dimethyl phthalate (DMP), the lowest-molecular-weight phthalate ester (PAE), is one of the most commonly detected persistent organic pollutants in the environment, but its toxic effects, especially cardiovascular developmental toxicity, are largely unknown. In this study, zebrafish embryos were exposed to sublethal concentrations of DMP from 4 to 96 hpf. Our results showed that DMP treatment induced yolk retention, pericardial edema, and swim bladder deficiency, as well as increased SV-BA distance and decreased heart rate, stroke volume, ventricular axis shortening rate and ejection fraction. In addition, oxidative stress and apoptosis were found to be highly involved in this process. The results of transcriptome sequencing and mRNA expression of related genes indicated that MAPK and calcium signaling pathways were perturbed by DMP. These findings have the potential to provide new insights into the potential developmental toxicity and cardiovascular disease risk of DMP.


Assuntos
Ácidos Ftálicos , Poluentes Químicos da Água , Peixe-Zebra , Animais , Peixe-Zebra/fisiologia , Sinalização do Cálcio , Embrião não Mamífero , Proteínas de Peixe-Zebra/metabolismo , Poluentes Químicos da Água/metabolismo
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