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1.
J Hazard Mater ; 391: 122211, 2020 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-32036315

RESUMO

This study aims to clarify the interaction mechanism of substrate with catechol 2,3-dioxygenase (C23O) through multi-technique combination. A novel C23O (named C23O-2G) was cloned, heterogeneously expressed, and identified as a new member in subfamily I.2 of extradiol dioxygenases. Based on the simulations of molecular docking and dynamics, the exact binding sites of catechol on C23O-2G were identified, and the catalytic mechanism mediated by key residues was proposed. The roles of the predicted residues during catalysis were confirmed by site-directed mutagenesis, and the mutation of Thr254 could significantly increase catalytic efficiency and substrate specificity of C23O-2G. The binding and thermodynamic parameters obtained from fluorescence spectra suggested that catechol could effectively quench the intrinsic fluorescence of C23O-2G via static and dynamic quenching mechanisms and spontaneously formed C23O-2G/catechol complex by the binding forces of hydrogen bond and van der Waals force. The results of UV-vis spectra, synchronous fluorescence, and CD spectra revealed obvious changes in the microenvironment and conformation of C23O-2G, especially for the secondary structure. The atomic force microscope images further demonstrated the changes from an appearance point of view. This study could improve our mechanistic understanding of representative dioxygenases involved in aromatic compound degradation.

2.
J Agric Food Chem ; 68(1): 48-58, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31829629

RESUMO

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) are perfluorinated alkyl substances widely used in industrial and domestic products. The European Food Safety Authority and United States Environmental Protection Agency have recently lowered the reference doses (RfDs) for PFOA and PFOS 4-1800-fold. The recently lowered RfDs call for re-evaluation of potential human health risks from PFOA and PFOS via food consumption. Serious concerns arise because some intakes of PFOA and PFOS exceeded the RfDs. Innovative cultivation of low-accumulating crop varieties becomes an option to decrease human exposure. We present an up-to-date review on low-accumulating crop varieties for PFOA and PFOS in reference to toxic metals and other organic pollutants, including the variety identification, physiological-biochemical mechanisms, molecular uptake mechanisms, and molecular docking, to call for attention and research efforts to decrease human intakes of PFOA and PFOS via crop consumption.


Assuntos
Ácidos Alcanossulfônicos/análise , Caprilatos/análise , Produtos Agrícolas/química , Fluorcarbonetos/análise , Contaminação de Alimentos/prevenção & controle , Ácidos Alcanossulfônicos/metabolismo , Caprilatos/metabolismo , Qualidade de Produtos para o Consumidor , Produtos Agrícolas/genética , Produtos Agrícolas/metabolismo , Fluorcarbonetos/metabolismo , Contaminação de Alimentos/análise , Inocuidade dos Alimentos , Humanos , Melhoramento Vegetal
3.
Environ Int ; 133(Pt A): 105142, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31513927

RESUMO

Frequent cyanobacterial blooms in the eutrophic waters produce a variety of toxins such as the monocyclic heptapeptide microcystins, greatly harming aquatic ecosystems and human health. However, little information of microcystins in agricultural fields is known. This field study of three common microcystin variants (MC-LR, MC-RR, and MC-YR) in vegetables (n = 161), soils (n = 161) and irrigation water samples (n = 23) collected from southern China regions affected by cyanobacteria blooms, shows their prevalence with total concentrations up to 514 µg/L water, 187 µg/kg soil (dry weight) and 382 µg/kg vegetable (fresh weight). MC-RR was the primary variant in all types of samples, accounting for 51.3-100% of total microcystin concentrations. Significant concentration-dependent correlations (p < 0.05) demonstrated that microcystin-contained irrigation waters were the major source of microcystin accumulation in both vegetables and soils. Meanwhile, intracellular-microcystins in irrigation water was found to play an important role in microcystins bioaccumulation in vegetables for the first time. Most vegetable samples (≥60%), particularly celery posed moderate or high human health risk via diet based on toxicity equivalents of the microcystins and reference dose for MC-LR (0.04 µg/kg/d), showing high food safety hidden dangers. Soil microcystins, especially MC-RR in 46.4-88.3% of soils could pose high ecological risks. This study highlights the potential high ecological and human health risks of microcystins in the real soil-vegetable systems of areas affected by cyanobacteria blooms, implying the profound significance and urgent need of investigation on microcystins in terrestrial ecosystems.

4.
Ying Yong Sheng Tai Xue Bao ; 30(8): 2845-2853, 2019 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-31418211

RESUMO

The safety of feed derived from genetically modified (GM) crops is one of the focuses of attention. To evaluate the ecotoxicological effects of transgenic mCry1Ac maize (BT799) on fish, zebrafish (Danio rerio) were fed extruded feeds containing either 20% GM maize (GMF) or its parental control maize (PF), GM maize meal (GMM) or its parental control maize meal (PMM), and a control commercial feed (CF), respectively. The growth performance, histopathology, reproduction, antioxidant enzyme activity and mRNA expression levels of sensitive protein in the liver were investigated over the course of a 98-day feeding trial. The results showed that transgenic mCry1Ac maize had no significant effect on growth, histopathology of the liver, brain and intestinal tract, fecundity, hatching rate of fertilized eggs, superoxide dismutase (SOD), catalase (CAT) activity, mRNA expression levels of SOD and CAT, or heat shock protein 70 (HSP70) and vitellogenin (VTG) in the liver. However, zebrafish fed the commercial feed exhibited significantly greater weight, longer length, and higher specific growth rate than those fed feeds (GMF and PF) and maize meals (GMM and PMM). The hatching rate of zebrafish in the feed groups was significantly lower than that of the maize meal groups and the commercial feed group. The mRNA transcriptional levels of VTG were significantly higher in the liver for the feed groups (3.85±0.76) than that for the maize meal groups (1.60±0.56). These results suggest that transgenic mCry1Ac maize has no ecotoxicological effects on zebrafish. However, the differences in nutrient composition and palatability between the extruded experimental feeds and the commercial feed would lead to significant diffe-rences in some parameters.


Assuntos
Alimentos Geneticamente Modificados , Zea mays/genética , Ração Animal , Animais , Plantas Geneticamente Modificadas , Testes de Toxicidade , Peixe-Zebra/fisiologia
5.
J Agric Food Chem ; 67(25): 6940-6949, 2019 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-31021627

RESUMO

This work developed a bioaugmentation strategy that simultaneously reduced soil di(2-ethylhexyl) phthalate (DEHP) pollution and its bioaccumulation in Brassica parachinensis by inoculating the isolated strain Rhodococcus sp. 2G. This strain could efficiently degrade DEHP at a wide concentration range from 50 to 1600 mg/L and transformed DEHP through a unique biochemical degradation pathway that distinguished it from other Rhodococcus species. Besides, strain 2G colonized well in the rhizosphere soil of the inoculated vegetable without competition with indigenous microbes, resulting in increased removal of DEHP from soil (∼95%) and reduced DEHP bioaccumulation in vegetables (∼75% in the edible part) synchronously. Improved enzyme activities and DOC content in the rhizosphere of the planting vegetable and inoculating strain 2G were responsible for the high efficiency in mitigating DEHP contamination to vegetable cultivation. This work demonstrated a great potential application to grow vegetables in contaminated soil for safe food production.


Assuntos
Inoculantes Agrícolas/metabolismo , Brassica/crescimento & desenvolvimento , Produção Agrícola/métodos , Dietilexilftalato/metabolismo , Rhodococcus/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Verduras/crescimento & desenvolvimento , Biodegradação Ambiental , Brassica/metabolismo , Brassica/microbiologia , Rizosfera , Verduras/metabolismo , Verduras/microbiologia
6.
Sci Total Environ ; 668: 1117-1127, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31018452

RESUMO

Crops can take up and accumulate di-n-butyl phthalate (DBP), an extensively used plasticizer with endocrine disrupting effect, which poses potential risk to human health. Our previous study found the genotype variation in accumulation of DBP by different cultivars of rice (Oryza sativa L.). Nevertheless, the effect of DBP metabolism in vivo on the accumulation variation among different plant cultivars remains unknown. In this study, metabolism variation of DBP by low (Fengyousimiao) and high (Peizataifeng) DBP-accumulating cultivars of rice and the key enzymes involving in DBP metabolism in rice plants were investigated using in vivo exposure of rice plants and in vitro exposure of root crude enzyme extracts. Both mono-n-butyl phthalate (MBP) and phthalic acid (PA) were detected as DBP metabolites in all rice tissues (i.e., roots, stems, leaves) and crude enzyme extracts with MBP predominance. DBP metabolism occurred simultaneously when DBP uptake with the highest metabolism in roots in vivo. Degradation of DBP in root crude enzyme extracts fitted well with the first order kinetics (R2 = 0.49-0.76, P < 0.05). The activity of carboxylesterase (CXE) in root crude enzyme extracts was significantly positively correlated with DBP degradation rates. CXE played an important role in DBP metabolism of rice plants, confirming by the fact that triphenyl phosphate of CXE inhibitor could inhibit DBP metabolism of in vivo and in vitro exposure. This result was further confirmed by in vitro degradation of DBP with the commercial pure CXE. The crude enzyme solution from roots of Fengyousimiao with higher CXE activity had significantly higher DBP degradation rates than that of Peizataifeng. However, Fengyousimiao with lower tolerance to DBP stress and higher inhibition by triphenyl phosphate displayed lower DBP metabolism ability in vivo than Peizataifeng.


Assuntos
Dibutilftalato/metabolismo , Oryza/metabolismo , Poluentes do Solo/metabolismo , Biodegradação Ambiental , Misturas Complexas/metabolismo , Oryza/enzimologia , Oryza/genética , Proteínas de Plantas/isolamento & purificação , Proteínas de Plantas/metabolismo
7.
Sci Total Environ ; 665: 41-51, 2019 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-30772572

RESUMO

Ciprofloxacin is a broad spectral and highly refractory antibiotic. It is an emerging pollutant. This study aimed to utilise co-metabolism as a means to degrade ciprofloxacin by a bacterial consortium. The stable bacterial consortium XG capable of efficiently degrading ciprofloxacin was successfully established through successive acclimation of indigenous microorganisms. The consortium XG was primarily consisted of Achromobacter, Bacillus, Lactococcus, Ochrobactrum, and Enterococcus as well as at least other five minor genera. A novel strain YJ17 with CIP-degrading ability was isolated from the consortium and identified as Ochrobactrum sp. The consortium XG utilised amino acids, carbohydrates, and carboxylic acids at a rate approximately 16.6-243-fold greater than the other carbon substrates, but only slow utilisation of ciprofloxacin as a sole carbon source. Ciprofloxacin can be co-metabolized along with many carbon sources, attaining degradation rates up to 63%. Glycyl-l-glutamic acid, d-cellobiose, and itaconic acid are among the substrates most favourable for co-metabolism. The metabolites of ciprofloxacin were identified by LC-QTOF-MS. Co-metabolic degradation of ciprofloxacin by consortium XG led to the removal of essential functional groups from parent compound, thus resulting in formation of metabolites with less bioactive potency. Finally, a possible biochemical pathway for the degradation of ciprofloxacin was proposed. Consortium XG possesses high potential for bioremediation of ciprofloxacin-contaminated environments in the presence of a co-substrate.


Assuntos
Biodegradação Ambiental , Ciprofloxacino/metabolismo , Poluentes Ambientais/metabolismo , Consórcios Microbianos , Antibacterianos/metabolismo , Ochrobactrum/metabolismo
8.
Bull Environ Contam Toxicol ; 102(4): 589-594, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30788561

RESUMO

Cadmium (Cd) is one of the hazardous environmental pollutants, and it can be harmful to human health through consumption of food-plants capable of bioaccumulating Cd. Therefore, lowering cadmium accumulation in plants is highly desirable. Here, a rice cultivar 'Qisanzhan' was studied using differential display reverse transcription-polymerase chain reaction (DDRT-PCR). Fifty-six differentially expressed genes were found in the root tips of 4-leaf stage rice seedlings exposed to 4 and 12 h of 50 µmol/L Cd(NO3)2 in a nutrient solution using DDRT-PCR. Further validation using semi-quantitative RT-PCR showed that the expression patterns of 16 genes were consistent with those found in DDRT-PCR. These genes encode receptor-like protein kinase, pleiotropic drug resistance protein, aquaporin protein, plasma membrane ATPase, etc. The differentially genes identified here can be used to obtain a better understanding of the molecular mechanisms of Cd absorption and accumulation in plants.


Assuntos
Cádmio/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Oryza/metabolismo , Proteínas de Plantas/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Perfilação da Expressão Gênica , Humanos , Oryza/genética , Proteínas de Plantas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Plântula/efeitos dos fármacos , Plântula/metabolismo , Estresse Fisiológico/genética
9.
Sci Total Environ ; 658: 474-484, 2019 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-30579204

RESUMO

A great amount of insoluble phosphate in agricultural soils is not available for crops. Three strains of bacteria (Bacillus megaterium YLYP1, Pseudomonas prosekii YLYP6 and Pseudomonas sp. YLYP29) isolated from activated sludge and soil could efficiently solubilise tricalcium phosphate. In particular, the novel strain P. prosekii YLYP6 produced 716 mg L-1 of available phosphate within 6 days under the optimal culture conditions [20 °C, pH 7.9, inoculum size of 0.5% (v:v)] determined by response surface methodology. P. prosekii YLYP6 demonstrated efficient phosphate solubilisation in response to broad variations in pH (5-9) and temperature (15-35 °C). The phosphate solubilisation curves of the strains fit well with a first-order kinetic model (R2 > 0.939), with a half-life of 1.51-5.94 d for 5.0 g L-1 calcium phosphate. Continuous culture experiments combined with scanning electron microscopic observations and gas chromatography-mass spectrometry analysis revealed that 2,3-dimethylfumaric acid, gluconic and N-butyl-tert-butylamine that were produced by P. prosekii YLYP6 were responsible for phosphate solubilisation by supplying H+ ions and organic anions. Efficient phosphate solubilisation in actual soil by P. prosekii YLYP6 demonstrated the strong application potential to reduce the use of chemical P fertilisers and the resulting agricultural nonpoint pollution.


Assuntos
Bacillus megaterium/metabolismo , Fosfatos de Cálcio/metabolismo , Pseudomonas/metabolismo , Esgotos/microbiologia , Microbiologia do Solo , Bacillus megaterium/isolamento & purificação , Cromatografia Gasosa-Espectrometria de Massas , Microscopia Eletrônica de Varredura , Pseudomonas/isolamento & purificação , Solo/química
10.
J Agric Food Chem ; 66(51): 13541-13551, 2018 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-30525579

RESUMO

Di- n-butyl phthalate (DBP), as an endocrine-disrupting chemical that tends to be accumulated in crops, poses great risks to human health through the food chain. To identify the molecular mechanism underlying differences in their DBP accumulation, the root physiological and proteomic responses to DBP stress of two Brassica parachinensis cultivars, a high-DBP accumulator (Huaguan) and a low-DBP accumulator (Lvbao), were investigated. Root damage of greater severity and significantly greater ( p < 0.05) decreases in root protein content and root activity were detected in Lvbao than in Huaguan, suggesting that Lvbao had lower tolerance to DBP. In total, 52 DBP-responsive proteins were identified by two-dimensional electrophoresis and MALDI-TOF mass spectrometry. More proteins involved in basic metabolic processes, such as protein synthesis and energy metabolism, were downregulated in Lvbao, possibly explaining its lower tolerance and root damage. Several proteins involved in starch metabolism, cell-wall biosynthesis and modification, and stress response were activated in Huaguan, suggesting greater tolerance to DBP. Overall, differences in root proteome between the two cultivars might be responsible for the genotype-dependent DBP tolerance and accumulation in B. parachinensis.


Assuntos
Brassica/metabolismo , Dibutilftalato/metabolismo , Raízes de Plantas/metabolismo , Brassica/química , Brassica/genética , China , Dibutilftalato/análise , Disruptores Endócrinos/análise , Disruptores Endócrinos/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raízes de Plantas/química , Raízes de Plantas/genética , Proteômica , Poluentes do Solo/análise , Poluentes do Solo/metabolismo
11.
J Agric Food Chem ; 66(44): 11569-11579, 2018 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-30240199

RESUMO

Sorption of perfluorooctanoic acid (PFOA), a toxic and persistent organic pollutant, by various size fractions of an agricultural soil at environmentally relevant concentrations was evaluated. PFOA sorption to all fractions involved both film diffusion and intraparticle diffusion with the rate-limiting step by the latter. PFOA isotherm data fitted a linear model. Organic matter (OM), cation exchange capacity, pore volume, and the Brunauer-Emmett-Teller area played key roles in PFOA sorption. The sorption capacity followed the order of humic acid > clay (0.15-4.4 mm) > fine silt (1.9-39.8 mm) > coarse silt (17.3-79.4 mm) > fine sand (45.7-316.2 mm) > coarse sand (120-724.4 mm), opposite to their contributions to overall PFOA sorption due to the influence of their percentage weight in the original soil. Percentage OM content was the dominant factor controlling the fraction contributions to overall PFOA sorption, demonstrating influence of the hydrophobic force on sorption. PFOA should be highly mobile and bioavailable in soil-crop systems due to the low log Koc values.


Assuntos
Caprilatos/química , Fluorcarbonetos/química , Praguicidas/química , Poluentes do Solo/química , Solo/química , Adsorção , Substâncias Húmicas/análise , Cinética , Tamanho da Partícula
12.
Ecotoxicol Environ Saf ; 163: 567-576, 2018 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-30077154

RESUMO

Di-(2-ethylhexyl) phthalate (DEHP) is a typical endocrine disrupting chemical with relatively high concentrations in agricultural soils of China. Here, a rhizobox experiment was conducted to investigate the variations in microbial community and DEHP dissipation among different soil rhizospheric compartments between low (Fengyousimiao) and high (Peizataifeng) DEHP-accumulating cultivars of rice (Oryza sativa L.) grown in DEHP spiked soil (0, 20, 100 mg/kg). The dissipation rates of DEHP in rhizospheric soils of Peizataifeng were generally significantly higher than those of Fengyousimiao, with the highest removal rate in 0-2 mm rhizosphere. The results of Illumina-HiSeq high-throughput sequencing revealed that both bacterial and fungal diversity and community structure were significantly different in rhizospheric soils of the two cultivars. DEHP dissipation rates in 0-2 mm rhizosphere of Peizataifeng were positively correlated with bacterial and fungal diversity. The relative abundance of DEHP-degrading bacterial genera Acinetobacter, Pseudomonas and Bacillus of Peizataifeng was generally higher than those in the same rhizospheric compartment of Fengyousimiao in DEHP treatments, resulting in different rhizospheric DEHP dissipation. Cultivation of Peizataifeng in agricultural soil is promising to facilitate DEHP dissipation and ensure safety of agricultural products.


Assuntos
Dietilexilftalato/análise , Oryza/microbiologia , Rizosfera , Microbiologia do Solo , Poluentes do Solo/análise , Solo/química , Agricultura , China , Dietilexilftalato/química , Dietilexilftalato/metabolismo , Oryza/química , Oryza/metabolismo , Ácidos Ftálicos , Poluentes do Solo/química
13.
Sci Total Environ ; 640-641: 1121-1131, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-30021277

RESUMO

A novel bacterial strain designated as Rhodococcus pyridinivorans XB, capable of utilizing various endocrine disruptor phthalates or phthalic acid (PA) as sole source of carbon and energy, was isolated from activated sludge. Under the optimal culture conditions (pH 7.08, 30.4 °C, inoculum size (OD600 nm) of 0.6) obtained by response surface methodology, di-(2-ethylhexyl) phthalate (DEHP, 200 mg/L) could be degraded by strain XB with a removal rate of 98% within 48 h. Under the observation of an atomic force microscope, it was confirmed that DEHP did not inhibit the growth of strain XB which might produce some extracellular polymeric substances as a response to DEHP stress, resulting in rapid degradation of DEHP. At initial concentrations of 50-800 mg/L DEHP, its degradation curves were well fitted with the first-order kinetic model, and the half-life of DEHP degradation varied from 5.44 to 23.5 h. The degradation intermediates of DEHP were identified by both GC-MS and high performance liquid chromatography-time of flight-mass spectrometry (HPLC-TOF-MS). Significant up-regulation was observed for the relative expression levels of genes (i.e., phthalate hydrolase, PA 3,4-dioxygenase, protocatechuate 3,4-α and 3,4-ß dioxygenase) involved in DEHP degradation determined by real-time quantitative PCR (RT-qPCR). A DEHP biodegradation pathway by strain XB was proposed based on the identified intermediates and the degrading genes. Bioaugmentation of DEHP-contaminated soils with strain XB could efficiently promote DEHP removal, offering great potential in bioremediation of DEHP-contaminated environment.


Assuntos
Biodegradação Ambiental , Dietilexilftalato/metabolismo , Rhodococcus/fisiologia , Poluentes do Solo/metabolismo , Ácidos Ftálicos , Solo
14.
Sci Total Environ ; 640-641: 646-652, 2018 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-29870940

RESUMO

Microbial degradation is considered the most promising method for removing phthalate acid esters (PAEs) from polluted environments; however, a comprehensive genomic understanding of the entire PAE catabolic process is still lacking. In this study, the repertoire of PAE catabolism genes in the metabolically versatile bacterium Rhodococcus sp. 2G was examined using genomic, metabolic, and bioinformatic analyses. A total of 4930 coding genes were identified from the 5.6 Mb genome of the 2G strain, including 337 esterase/hydrolase genes and 48 transferase and decarboxylase genes that were involved in hydrolysing PAEs into phthalate acid (PA) and decarboxylating PA into benzoic acid (BA). One gene cluster (xyl) responsible for transforming BA into catechol and two catechol-catabolism gene clusters controlling the ortho (cat) and meta (xyl &mhp) cleavage pathways were also identified. The proposed PAE catabolism pathway and some key degradation genes were validated by intermediate-utilising tests and real-time quantitative polymerase chain reaction. Our results provide novel insight into the mechanisms of PAE biodegradation at the molecular level and useful information on gene resources for future studies.


Assuntos
Biodegradação Ambiental , Ácidos Ftálicos/metabolismo , Rhodococcus/genética , Ésteres , Genômica
15.
Sci Total Environ ; 636: 999-1008, 2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-29729517

RESUMO

The cultivation of crop cultivars with low pollutant accumulation is an important strategy to reduce the potential health risks of food produced from polluted soils. In this study, we identified three loose-leaf lettuce cultivars with low accumulation of perfluorooctanoic acid (PFOA), a highly toxic and persistent organic pollutant. PFOA concentrations in the shoots of low-PFOA cultivars were 3.7-5.5-fold lower than those of high-PFOA cultivars. The identification of low-PFOA cultivars could contribute to ensuring food safety despite cultivation in highly polluted soils (1 mg/kg) based on the tolerable daily PFOA intake (1.5 µg/kg/d). We detected lower desorbing fractions of PFOA in rhizosphere soil, lower bioconcentration factors, and higher distribution in the cell walls and organelles of roots in low-PFOA cultivars, all of which are key factors in limiting PFOA uptake and translocation from soil to shoots, than in high-PFOA cultivars. This study reveals the mechanism of PFOA uptake from soil to crop and lays a foundation for establishing a cost-effective strategy to plant crops in polluted soil and reduce exposure risk due to persistent organic pollutants in crops.


Assuntos
Caprilatos/metabolismo , Fluorcarbonetos/metabolismo , Alface/fisiologia , Poluentes do Solo/metabolismo , Caprilatos/análise , Fluorcarbonetos/análise , Alface/genética , Raízes de Plantas , Solo , Poluentes do Solo/análise
16.
J Agric Food Chem ; 66(18): 4768-4779, 2018 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-29683662

RESUMO

iTRAQ analysis was used to map the proteomes of two Brassica parachinensis cultivars that differed in dibutyl phthalate (DBP) accumulation. A total of 5699 proteins were identified to obtain 152 differentially regulated proteins, of which 64 and 48 were specific to a high- and a low-DBP-accumulation cultivar, respectively. Genotype-specific biological processes were involved in coping with DBP stress, accounting for the variation in DBP tolerance and accumulation. Formation of high DBP accumulation in B. parachinensis might attribute to the more effective regulation of protein expression in physiology and metabolism, including (a) enhanced cell wall biosynthesis and modification, (b) better maintenance of photosynthesis and energy balance, (c) greatly improved total capacity for antioxidation and detoxification, and (d) enhanced cellular transport and signal transduction. Our novel findings contribute to a global picture of DBP-induced alterations of protein profiles in crops and provide valuable information for the development of molecular-assisted breeds of low-accumulation cultivars.


Assuntos
Brassica/efeitos dos fármacos , Dibutilftalato/farmacocinética , Proteínas de Plantas/genética , Plastificantes/farmacologia , Brassica/química , Brassica/genética , Brassica/metabolismo , Parede Celular/efeitos dos fármacos , Parede Celular/genética , Parede Celular/metabolismo , Dibutilftalato/análise , Dibutilftalato/metabolismo , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Proteínas de Plantas/metabolismo , Plastificantes/análise , Plastificantes/metabolismo , Poluentes do Solo/análise , Poluentes do Solo/metabolismo , Poluentes do Solo/farmacologia
17.
Sci Total Environ ; 634: 417-426, 2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-29627565

RESUMO

A pot experiment was conducted to investigate the effect of a series of ß-cyclodextrin (ß-CD) concentrations on bioremediation of soil co-contaminated with Cd and BDE-209 using amaranth and the white-rot fungus Phanerochaete chrysosporium, with BDE-209 degrading ability. Results showed that the white-rot fungus was beneficial to the growth of amaranth, Cd uptake and BDE-209 degradation. Addition of ß-CD further increased biomass of both shoots and roots, shoot Cd concentrations and contents, chlorophyll concentrations and soil manganese peroxidase (MnP) activities. Furthermore, well-organized mesophyll cells were observed in ß-CD treatments, implying that the combination of white-rot fungus and ß-CD can alleviate the stresses of Cd and BDE-209 to mesophyll cells. The BDE-209 degradation rate was positively correlated to ß-CD concentration and MnP activity in soil. Our results also revealed that RF+ß0.8 treatment possessed the greatest Cd removal efficiency due to its well-configured mesophyll cells and the highest shoot biomass, chlorophyll concentration, and shoot Cd concentration. Considering simultaneous removal of Cd and BDE-209 from soil, using 0.8% ß-CD to amaranth inoculated with white-rot fungus is a promising way forward for the phytoremediation of soil co-contaminated with Cd and BDE-209. A high percentage of mono-BDE was detected in inoculated amaranth, suggesting that BDE-209 was debrominated into low brominated PBDEs by the fungus in soil, which were then absorbed and further debrominated into mono-BDE in the plant.


Assuntos
Biodegradação Ambiental , Cádmio/metabolismo , Éteres Difenil Halogenados/metabolismo , Phanerochaete/metabolismo , Poluentes do Solo/metabolismo , beta-Ciclodextrinas/metabolismo , Amaranthus/microbiologia , Solo
18.
Environ Res ; 164: 417-429, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29573717

RESUMO

Phthalates (PAEs) are extensively used as plasticizers and constitute one of the most frequently detected organic contaminants in the environment. With the deterioration of eco-environment in China during the past three decades, many studies on PAE occurrence in soils and their risk assessments have been conducted which allow us to carry out a fairly comprehensive assessment of soil PAE contamination on a nation-wide scale. This review combines the updated information available associated with PAE current levels, distribution patterns (including urban soil, rural or agricultural soil, seasonal and vertical variations), potential sources, and human health exposure. The levels of PAEs in soils of China are generally at the high end of the global range, and higher than the grade II limits of the Environmental Quality Standard for soil in China. The most abundant compounds, di-n-butyl phthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP), display obvious spatial distribution in different provinces. It is noted that urbanization and industrialization, application of plastic film (especially plastic film mulching in agricultural soil) and fertilizer are the major sources of PAEs in soil. Uptake of PAEs by crops, and human exposure to PAEs via ingestion of soil and vegetables are reviewed, with scientific gaps highlighted.


Assuntos
Ácidos Ftálicos , Poluentes do Solo , China , Humanos , Ácidos Ftálicos/análise
19.
J Hazard Mater ; 349: 252-261, 2018 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-29433110

RESUMO

To investigate the mechanism of genotype differences in ciprofloxacin (CIP) accumulation, this study was designed to compare the tolerance and metabolic responses to CIP exposure between low (Cutai) and high (Sijiu) CIP-accumulation cultivars of Brassica parachinensis. Decreases in biomass and chlorophyll content were significantly greater (p < 0.05) and toxicities were more severe within cell ultrastructures of Cutai compared to Sijiu. A sequential growth test also revealed that Sijiu was more tolerant to CIP stress compared to Cutai. Meanwhile, significantly higher (p < 0.05) root parameters and higher areas of the stele and xylem may be responsible for the increased uptake and transport of CIP in Sijiu. Ultra performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) analysis revealed that CIP was metabolized to three major metabolites by the hydroxylation and breakdown of the piperazinyl substituent in the CIP molecule. The enhanced metabolic transformation of CIP in Sijiu indicated a more efficient capacity to detoxify, which in turn favored an increased accumulation of CIP in this cultivar. Thus, the present study demonstrated that the stronger tolerance and metabolism of Sijiu to CIP were responsible for its high CIP accumulation, suggesting an evolutionary mechanism for adaptation to environmental stress.


Assuntos
Antibacterianos/metabolismo , Brassica/metabolismo , Ciprofloxacino/metabolismo , Poluentes do Solo/metabolismo , Adaptação Fisiológica , Brassica/genética , Brassica/crescimento & desenvolvimento , Clorofila/metabolismo , Genótipo , Folhas de Planta/genética , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/anatomia & histologia , Raízes de Plantas/genética , Raízes de Plantas/crescimento & desenvolvimento
20.
Ecotoxicol Environ Saf ; 154: 84-91, 2018 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-29454990

RESUMO

Aniline aerofloat (AAF), a high-toxic organic flotation reagent, is widely used in mineral processing industry. However, little information on its environmental fate is available. AAF sorption to four types of agricultural soils at low concentrations (1-10 mg/L) was investigated using batch experiments. AAF sorption kinetics involved both boundary layer diffusion and intraparticle diffusion, following pseudo-second-order kinetics with equilibrium time within 120 min. Both Langmuir and Freundlich models fitted well the AAF sorption with the former better. Sorption of AAF to soils was a spontaneous and favorable physical sorption that was controlled by ion bridge effect and hydrophobic interaction that was related to van der Waals force and π-π coordination based on FTIR analyses. AAF sorption was remarkably affected by soil constituents, positively correlating with the contents of organic matter and clay. The relatively higher logKoc values (3.53-4.66) of AAF at environmental concentrations (1-5 mg/L) imply that soils are serving as a sink of AAF from beneficiation wastewater, posing great potential risks to environment and human health.


Assuntos
Compostos de Anilina/análise , Modelos Teóricos , Poluentes do Solo/análise , Solo/química , Adsorção , Agricultura , Silicatos de Alumínio/análise , Argila , Difusão , Humanos , Substâncias Húmicas/análise , Cinética , Águas Residuárias/química
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