Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.710
Filtrar
1.
Environ Monit Assess ; 191(9): 530, 2019 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-31372746

RESUMO

Activities in the Bangladeshi leather industries have the potential to cause chemical pollutions thereby deteriorating the working environments, the surrounding residential areas, or even foodstuffs. Therefore, it is important to determine the chemical exposures among the industry workers and residents of the surrounding areas who may be directly or indirectly impacted by the contaminated environment. This study focused on evaluating the hazard arising from exposure to metals due to industrial contamination. Tissue samples of hair and nails were collected from both the leather industry workers and residents in the vicinity of the industries. Using chromium as an indicator of contamination/exposure from the leather industry, it was the most significant metal contaminant for industry workers ranging from 21.85 to 483 mg/kg and for industry-neighboring residents at 6.01 to 296.16 mg/kg. Both the workers and neighboring residents were found to be excessively exposed (P < 0.05) to chromium compared with the investigated control group of people living in a distant village area which had no industrial establishments.


Assuntos
Monitoramento Ambiental , Poluição Ambiental , Intoxicação por Metais Pesados , Metais Pesados/toxicidade , Exposição Ocupacional , Bangladesh , Cromo/análise , Cabelo/química , Humanos , Indústrias , Metais Pesados/análise , Unhas/química
2.
Gene ; 718: 144048, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31421189

RESUMO

Main conclusion Among 247 RsAP2/ERF identified, the majority of the 21 representatives were preferably expressed under drought and heat while suppressed under heavy metals, indicating their potential roles in abiotic stress responses and tolerance. APETALA2/Ethylene-Responsive factor (AP2/ERF) transcription factor (TF) is one of the largest gene families in plants that play a fundamental role in growth and development as well as biotic and/or abiotic stresses responses. Although AP2/ERFs have been extensively characterized in many plant species, little is known about this family in radish, which is an important root vegetable with various medicinal properties. The available genome provides valuable opportunity to identify and characterize the global information on AP2/ERF TFs in radish. In this study, a total of 247 ERF family genes were identified from the radish genome, and sequence alignment and phylogenetic analyses classified the AP2/ERF superfamily into five groups (AP2, ERF, DREB, RAV and soloist). Motif analysis showed that other than AP2/ERF domains, other conserved regions were selectively distributed among different clades in the phylogenetic tree. Chromosome location analysis showed that tandem duplication may result in the expansion of RsAP2/ERF gene family. The RT-qPCR analysis confirmed that a proportion of AP2/ERF genes were preferably expressed under drought and heat stresses, whereas they were suppressed under the ABA and heavy metal stresses. These results provided valuable information for further evolutionary and functional characterization of RsAP2/ERF genes, and contributed to genetic improvement of stress tolerances in radish and other root vegetable crops.


Assuntos
Evolução Molecular , Proteínas de Homeodomínio , Metais Pesados/toxicidade , Família Multigênica , Proteínas Nucleares , Filogenia , Proteínas de Plantas , Raphanus , Estresse Fisiológico/efeitos dos fármacos , Estudo de Associação Genômica Ampla , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Raphanus/genética , Raphanus/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
3.
World J Microbiol Biotechnol ; 35(9): 132, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31432260

RESUMO

This paper aims to characterize halophilic bacteria inhabiting Algerian Saline Ecosystems (Sebkha and Chott) located in arid and semi-arid ecoclimate zones (Northeastern Algeria). In addition, screening of enzymatic activities, heavy metal tolerance and antagonistic potential against phytopathogenic fungi were tested. A total of 74 bacterial isolates were screened and phylogenetically characterized using 16S rRNA gene sequencing. The results showed a heterogeneous group of microorganisms falling within two major phyla, 52 strains belonging to Firmicutes (70.2%) and 22 strains (30.8%) of γ-Proteobacteria. In terms of main genera present, the isolates were belonging to Bacillus, Halobacillus, Lentibacillus, Oceanobacillus, Paraliobacillus, Planomicrobium, Salicola, Terribacillus, Thalassobacillus, Salibacterium, Salinicoccus, Virgibacillus, Halomonas, Halovibrio, and Idiomarina. Most of the enzymes producers were related to Bacillus, Halobacillus, and Virgibacillus genera and mainly active at 10% of growing salt concentrations. Furthermore, amylase, esterase, gelatinase, and nuclease activities ranked in the first place within the common hydrolytic enzymes. Overall, the isolates showed high minimal inhibitory concentration values (MIC) for Ni2+ and Cu2+ (0.625 to 5 mM) compared to Cd2+ (0.1 to 2 mM) and Zn2+ (0.156 to 2 mM). Moreover, ten isolated strains belonging to Bacillus, Virgibacillus and Halomonas genera, displayed high activity against the pathogenic fungi (Botrytis cinerea, Fusarium oxyporum, F. verticillioides and Phytophthora capsici). This study on halophilic bacteria of unexplored saline niches provides potential sources of biocatalysts and novel bioactive metabolites as well as promising candidates of biocontrol agents and eco-friendly tools for heavy metal bioremediation.


Assuntos
Antibiose , Bactérias/isolamento & purificação , Bactérias/metabolismo , Biota , Microbiologia Ambiental , Salinidade , Argélia , Bactérias/classificação , Bactérias/genética , Análise por Conglomerados , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Fungos/crescimento & desenvolvimento , Hidrolases/análise , Metais Pesados/metabolismo , Metais Pesados/toxicidade , Testes de Sensibilidade Microbiana , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
4.
Environ Pollut ; 252(Pt B): 1582-1592, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31279252

RESUMO

Localised sites in Antarctica are contaminated with mixtures of metals, yet the risk this contamination poses to the marine ecosystem is not well characterised. Recent research showed that two Antarctic marine microalgae have antagonistic responses to a mixture of five common metals (Koppel et al., 2018a). However, the metal accumulating potential and risk to secondary consumers through dietary exposure are still unknown. This study investigates cellular accumulation following exposure to a mixture of cadmium, copper, nickel, lead, and zinc for the Antarctic marine microalgae, Phaeocystis antarctica and Cryothecomonas armigera. In both microalgae, cellular cadmium, copper, and lead concentrations increased with increasing exposures while cellular nickel and zinc did not. For both microalgae, copper in the metal mixture drives inhibition of growth rate with R2 values > -0.84 for all cellular fractions in both species and the observed antagonism was likely caused by zinc competition, having significantly positive partial regressions. Metal accumulation to P. antarctica and C. armigera is likely to be toxic to consumer organisms, with low exposure concentrations resulting in cellular concentrations of 500 and 1400 × 10-18 mol Zn cell-1 and 160 and 320 × 10-18 mol Cu cell-1, respectively.


Assuntos
Haptófitas/química , Metais Pesados/análise , Microalgas/química , Poluentes Químicos da Água/análise , Animais , Regiões Antárticas , Exposição Dietética/análise , Cadeia Alimentar , Haptófitas/crescimento & desenvolvimento , Metais Pesados/toxicidade , Microalgas/crescimento & desenvolvimento , Modelos Teóricos , Risco , Poluentes Químicos da Água/toxicidade
5.
Environ Sci Pollut Res Int ; 26(24): 25208-25217, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31256402

RESUMO

Currently, the emergence of clinically relevant multi-resistant bacteria and the associated ß-lactamases resistance genes which threaten the last frontier for antibiotics presents a major challenge for medical treatment. Xiangjiang River is typically contaminated with heavy metals due to the intensive metal mining activities within this watershed. The occurrence and distribution of several ß-lactam antibiotics and ten ß-lactam resistance genes (blaTEM, blaVIM, blaSHV, blaGES, blaDHA, blaOXA-1, blaOXA-2, blaOXA-10, blaCMY-2, and blaampC) were investigated in the Xiangjiang River, China. The absolute abundance of bla genes was as high as (7.0 ± 0.6) × 106 copies/mL for surface water and (2.3 ± 0.7) × 108 copies/g for sediment. In contrast, all the detected ß-lactam antibiotic compounds were below the detection limit. The distribution of individual bla gene subtypes was correlated with speciation of heavy metals which might affect the bacterial community structure. The principal coordinate analysis (PCoA) and Mantal test reconfirmed that the heavy metals had a correlation with the bla genes and the bla genes were correlated with bacterial community structure, suggesting that heavy metals impacted on the distribution of the bla genes by shifting bacterial community structure under the long-term selective pressure. The microcosm experiments indicated metal-induced persistence of bla genes in the resistant bacteria (Bacillus megaterium, Staphylococcus epidermidis). The persistence of ß-lactam resistance under metal selective pressure is beneficial to the survival of resistant bacteria, thereby contributing to the shift of the bacterial community structure, consequently impacts on the distribution of bla genes.


Assuntos
Metais Pesados/toxicidade , Rios/microbiologia , Poluentes Químicos da Água/toxicidade , Resistência beta-Lactâmica/genética , Bactérias/genética , Proliferação de Células/efeitos dos fármacos , China , Monitoramento Ambiental , Metais Pesados/análise , Microbiologia da Água , Poluentes Químicos da Água/análise , beta-Lactamases
6.
Ecotoxicol Environ Saf ; 182: 109399, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31279281

RESUMO

Soil washing with chelators, a viable method for treating soils contaminated with potentially toxic metals, has drawn increasing attentions. The objective of this study was to determine a new generation of mixed degradable chelating agents from N, N-bis (carboxymethyl) glutamic acid (GLDA), [S, S]-stereoisomer of ethyleneiaminedisucc--inic acid (EDDS), nitrilotriacetic acid (NTA), and citric acid (CA), and to evaluate its effectiveness and feasibility to reduce toxic metals contamination in two different agricultural soils. A comparative leaching test conducted on the four individual degradable chelating agents showed that the capacity of single chelator in mobilizing copper (Cu), zinc (Zn), cadmium (Cd), and lead (Pb) varied significantly. Using a combination of GLDA and NTA was more advantageous than using a single chelating agent in extracting potentially toxic metals. The removal efficiencies of Cu, Zn, Cd, and Pb reached 38.2, 9.8, 71.4, and 19.5% for soil 1, and 25.0, 5.2, 59.7, and 18.5% for soil 2, respectively, at mixed chelator (MC) concentrations of 3 mmol/L (GLDA) and 2 mmol/L (NTA), pH of 6.0, and a contact time of 4.0 h. The effects of washing conditions, chelator concentration, pH values, and contact time on the removal efficiencies of target toxic metals were investigated. The results showed that the combined chelating agent has a lower pH dependence, making it feasible for a wider range of applications. The effects of the chelating agents on the morphological distribution of potentially toxic metals and the soil enzyme activity before and after the treatments were also studied. After washing, the content of the water-soluble, acid-soluble, reducible, and oxidizable target metals showed a certain degree of decrease. Although the activities of catalase, urease, and invertase appeared to be inhibited during a short period of time, their activities were stimulated and later promoted with the degradation of the chelating agent. In general, the chelating agent combination has a great potential for toxic metals leaching.


Assuntos
Metais Pesados/química , Poluentes do Solo/química , Cádmio , Quelantes/química , Ácido Cítrico/química , Metais Pesados/análise , Metais Pesados/toxicidade , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/toxicidade , Zinco
7.
Environ Pollut ; 252(Pt B): 1097-1105, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31252107

RESUMO

The application of compost in agriculture has led to the accumulation of antibiotic resistance genes (ARGs) and heavy metal resistance genes (MRGs) in the soil environment. In this study, the response of ARGs and MRGs to bamboo charcoal (BC) and bamboo vinegar (BV) during aerobic composting was investigated. Results showed that BC + BV treatment reduced the abundances of ARGs and mobile genetic elements (MGEs) during the thermophilic period, as well as achieved the lowest rebound during the cooling period. BC + BV promoted the growth of Firmicutes, thereby facilitating the thermophilic period of composting. The rebound of ARGs and MGEs can be explained by increasing the abundance of Actinobacteria and Proteobacteria at the end of composting. Composting reduced the abundances of MRGs comprising pcoA, tcrB, and cueO, whereas cusA and copA indicated the selective pressure imposed by heavy metals on bacteria. The fate of ARGs was mainly driven by MGEs, and heavy metals explained most of the variation in MRGs. Interestingly, nitrogen conversion also had an important effect on ARG and MRG profiles. Our current findings suggest that the addition of BC + BV during compost preparation is an effective method in controlling the mobility of ARGs and MRGs, thereby reducing the environmental problems.


Assuntos
Ácido Acético/farmacologia , Carvão Vegetal/química , Compostagem , Resistência Microbiana a Medicamentos/genética , Genes Bacterianos/efeitos dos fármacos , Sasa/química , Aerobiose , Antibacterianos/toxicidade , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Metais Pesados/toxicidade , Nitrogênio/análise , Solo/química
8.
Environ Sci Pollut Res Int ; 26(23): 24162-24175, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31228056

RESUMO

Ship breaking and recycling industry (SBRI) loops back scarce ferrous and non-ferrous materials from dismantled ships and also renews the global shipping fleet by treating the end-of-life (EoL) ships. Currently, SBRIs in Bangladesh, India, and Pakistan are dismantling the majority of the EoL ships by open beaching method. Accordingly, ship dismantling carries the blame of releasing potentially toxic elements (PTEs) to the coastal and marine environment risking the food chain through potential bioaccumulation and biomagnification. Health risk assessment associated with PTEs from open beach ship dismantling is scarce. This study aimed at assessing concentrations and seasonal variations of PTEs in soils exposed to the activities of SBRIs for their source apportionment by using contamination factor (CF) and multivariate statistical analysis, while carcinogenic and non-carcinogenic health risks due to the PTEs have also been determined. Soil samples were collected twice-during pre-monsoon and post-monsoon seasons-from three working zones of each of the 15 different ship breaking yards spanning the entire SBRI zone in Bangladesh. Soil contamination was assessed by using the CF, and inverse distance weighting interpolation mapping showed the spatial distribution of metals at SBRI zone in Bangladesh. Multivariate statistical analysis, principal component analysis, and correlation matrix yielded the source apportionment of PTEs. Subsequently, carcinogenic and non-carcinogenic health risks were assessed following the approach recommended by the United States Environmental Protection Agency (USEPA) with uncertainty estimation through Monte Carlo simulation. Contamination levels of PTEs followed Cd > Zn > Cr > Cu > Pb > Ni > Mn > As. Concentrations of Cd, Cr, Mn, and Zn were higher than the maximum allowable regulatory limits at storage zone and also higher as compared with the beaching and cutting zones in general. The contamination index indicated extreme Cd contamination in the area with elevated levels in pre-monsoon. Two principal components (PC) were identified-PC1 (Cd, Cu, Mn, Pb, Zn) and PC2 (As, Cr, Ni) inferring their source segmentation. Indirect soil ingestion is the major possible exposure path to PTEs. The health index indicated the absence of any obvious health effects on the people active at SBRI yards in Bangladesh. The carcinogenic risk was for 6 to 7 persons per 100,000 people which was within the USEPA acceptable range.


Assuntos
Indústrias/métodos , Metais Pesados/análise , Medição de Risco/métodos , Navios , Poluentes do Solo/análise , Bangladesh , Carcinógenos/toxicidade , Exposição Ambiental/efeitos adversos , Monitoramento Ambiental/métodos , Humanos , Metais Pesados/toxicidade , Análise Multivariada , Exposição Ocupacional/efeitos adversos , Reciclagem , Estações do Ano , Poluentes do Solo/toxicidade
9.
Ecotoxicol Environ Saf ; 181: 301-307, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31202929

RESUMO

Metallothioneins (MTs) are a family of low molecular weight, cysteine-rich, metal-binding proteins, which play important roles in metal homeostasis and heavy metal detoxification. In our previous study, a novel full length MT cDNA was successfully cloned from the freshwater crab (Sinopotamon henanense). In the present study, tandem repeats of two and three copies of the crab MT gene were integrated by overlap extension PCR (SOE-PCR) and expressed in Escherichia coli. The SUMO fusion expression system was adopted to increase the stability and solubility of the recombinant MT proteins. The recombinant proteins were purified and their metal-binding abilities were further analyzed by the ultraviolet absorption spectral scan. Furthermore, the metal tolerance and bioaccumulation of E. coli cells expressing oligomeric MTs were determined. Results showed that the recombinant plasmids pET28a-SUMO-2MT and pET28a-SUMO-3MT were successfully constructed. SDS-PAGE analysis showed that the SUMO-2MT and SUMO-3MT were expressed mainly in the soluble forms. Oligomeric MTs expression significantly enhanced Cu, Cd or Zn tolerance and accumulation in E. coli in the order: SUMO-3MT˃SUMO-2MT˃SUMO-MT˃control. Cells harboring pET28a-SUMO -3MT exhibited the highest Cu, Cd or Zn bioaccumulation at 5.8-fold, 3.1-fold or 6.7-fold higher than that of the control cells. Our research could lay a foundation for large-scale preparation of MTs and provide a scientific basis for bioremediation of heavy metal pollution by oligomeric MTs.


Assuntos
Escherichia coli/genética , Metalotioneína/genética , Metais Pesados/metabolismo , Animais , Braquiúros/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/metabolismo , Metalotioneína/metabolismo , Metais Pesados/toxicidade , Proteínas Recombinantes de Fusão/metabolismo
10.
Ecotoxicol Environ Saf ; 181: 312-320, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31202931

RESUMO

The effect of manure compost alone and combined with Streptomyces pactum (Act12) applied in the smelter-contaminated soil was investigated. The soil fertility, enzymatic activities, potentially toxic metals (PTMs) solubility, and phytoremediation efficiency of potherb mustard (Brassica juncea, Coss.) were assessed. Results showed that the application of compost reduced the soil pH, while significantly increased the soil electrical conductivity (EC) (7.0 folds), available phosphorus (AP) (10.8 folds), available potassium (AK) (2.81 folds), dissolved organic carbon (DOC) (5.22 folds), organic matter (OM) (4.93 folds), together with soil enzymatic activities viz. urease (UR) (4.39 folds), dehydrogenase (DEH) (45.0 folds) and alkaline phosphatase (ALP) (123.9 folds) in comparison with control. The inoculation of Act12 increased AP, AK, DOC, OM and UR values, but reduced EC, DEH and ALP values compared to corresponding lone compost amendment. Additionally, Act12 solubilized PTMs (Cd and Zn) in the soil, and accordingly enhanced the PTMs uptake in the plant. The phytoextraction indices viz. biological concentration factor (BCF), translocation factor (TF) and metal extraction amount (MEA) indicated that compost and Act12 had a synergistic role in enhancing the phytoremediation efficiency, among which MEA values of Cd and Zn maximally increased by 9.64 and 11.4 folds, respectively, compared to control. Redundancy analysis (RDA) indicated that phytoextraction indices correlated well with soil parameters. Our results suggested that manure compost associated with Act12 is a potential strengthening strategy in phytoremediation of PTMs contaminated soil.


Assuntos
Compostagem , Metais Pesados/metabolismo , Poluentes do Solo/metabolismo , Streptomyces/fisiologia , Fosfatase Alcalina/metabolismo , Biodegradação Ambiental , Cádmio/metabolismo , Esterco , Metais Pesados/toxicidade , Mostardeira/metabolismo , Oxirredutases/metabolismo , Solo/química , Poluentes do Solo/toxicidade , Urease/metabolismo , Zinco/metabolismo
11.
Environ Sci Pollut Res Int ; 26(24): 24695-24706, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31240645

RESUMO

The biotoxicity of heavy metals in sediments toward benthic organisms has evoked great concern for the health of freshwater ecosystems. This study applied a sediment toxicity testing protocol to investigate the single and joint toxicity of cadmium (Cd) and lead (Pb) on Bellamya aeruginosa. B. aeruginosa were exposed to different concentrations of Cd (5, 25, and 100 mg/kg), Pb (20, 100, and 400 mg/kg), and their different concentration combinations. A suite of biomarkers, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), metallothionein (MT), malondialdehyde (MDA), and acetylcholinesterase (AChE), were measured after 7, 14, 21, and 28 days of exposure to evaluate their oxidative stress status. Cell apoptosis of soft tissue was also determined after exposure. Results revealed that these endpoints represented sensitive biomarkers for the characterization of the oxidative stress response induced by these metals. Specifically, a decrease of SOD and GPx and an increase of MDA were indicative of the potential failure of the antioxidant defense system in neutralizing the reactive oxygen species (ROS) generated in the exposure of the Pb-treated group. The integrated biomarker response (IBR) index revealed the most significant sub-lethal toxicity for Pb-spiked sediments, leading to the highest rate of cell apoptosis (70.8%). Exposure to Cd resulted in a time- and dose-dependent effect on MT levels, which suggested active detoxification of this metal. Exposure to the mixture resulted in amelioration of Pb toxicity, likely due to the competitive binding of Cd to active enzyme, with the result of an observed antagonistic interaction. This study indicated that B. aeruginosa represents a good biomonitor for assessing Cd and Pb contamination of sediments, and laid the foundation for their potential risk assessments in freshwater ecosystems.


Assuntos
Cádmio/toxicidade , Chumbo/toxicidade , Metalotioneína/metabolismo , Metais Pesados/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Pseudomonas aeruginosa/metabolismo , Animais , Biomarcadores/metabolismo , Catalase/metabolismo , Ecossistema , Água Doce , Glutationa Peroxidase/metabolismo , Malondialdeído/metabolismo , Metalotioneína/química , Pseudomonas aeruginosa/química , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase/metabolismo
12.
Ecotoxicol Environ Saf ; 180: 705-714, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31151067

RESUMO

Heavy metals and polybrominated diphenyl ethers (PBDEs) are ubiquitous pollutants at electronic waste (e-waste) contaminated sites, their individual impacts on soil microbial community has attracted wide attention, however, limited research is available on the combined effects of heavy metals and PBDEs on microbial community of e-waste contaminated. Therefore, combined effects of heavy metals and PBDEs on the microbial community in the e-waste contaminated soil were investigated in this study. Samples were collected from Ziya e-waste recycling area in Tianjin, northern China, and the soil microbial communities were then analyzed by the high-throughput MiSeq 16S rRNA sequencing to assess the effects of soil properties, heavy metals, and PBDEs on the soil microbial community. Candidatus Nitrososphaera, Steroidobacter and Kaistobacter were the dominant microbial species in the soils. Similar microbial metabolic functions, including amino acid metabolism, carbohydrate metabolism and membrane transport, were found in all soil samples. Redundancy analysis and variation partition analysis revealed that the microbial community was mainly influenced by PBDEs (including BDE 183, BDE 99, BDE 100 and BDE 154) in horizontal soil samples. However, TN, biomass, BDE 100, BDE 99 and BDE 66 were the major drivers shaping the microbial community in vertical soil samples.


Assuntos
Resíduo Eletrônico , Éteres Difenil Halogenados/toxicidade , Metais Pesados/toxicidade , Microbiota/efeitos dos fármacos , Microbiologia do Solo , China , Resíduo Eletrônico/análise , Monitoramento Ambiental , Éteres Difenil Halogenados/análise , Metais Pesados/análise , Microbiota/genética , Microbiota/fisiologia , RNA Ribossômico 16S/genética , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
13.
Mar Pollut Bull ; 142: 85-92, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31232352

RESUMO

Heavy metals may adversely affect health in marine organisms. As top predators, sharks may be especially vulnerable to exposure over long lifespans. Here we evaluate plasma levels of 14 heavy metals and 12 trace elements in white sharks, Carcharodon carcharias, in South Africa to determine whether they are related to sex, body size, and/or body condition and other health parameters. High levels of mercury and arsenic were found in shark blood at levels considered toxic in other vertebrates. Heavy metal concentrations were not related to body size or sex. Metal concentrations were not related to body condition with exception of copper, which was positively correlated. Protective effects of elements such as selenium, zinc, and iron were not detected. No negative effects on health parameters, such as total leukocytes or granulocyte to lymphocyte ratios were observed. Results suggest that sharks may have protective mechanisms that mitigate harmful effects of heavy metal exposure, providing new opportunities for future studies.


Assuntos
Metais Pesados/sangue , Tubarões/sangue , Poluentes Químicos da Água/sangue , Animais , Arsênico/sangue , Tamanho Corporal , Ecotoxicologia/métodos , Feminino , Contagem de Leucócitos , Masculino , Mercúrio/sangue , Metais Pesados/toxicidade , Tubarões/fisiologia , África do Sul , Oligoelementos/sangue , Poluentes Químicos da Água/toxicidade
14.
Chemosphere ; 233: 796-808, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31200138

RESUMO

Copper is one of common contaminants in estuaries and coastal zones, which may cause physiological dysfunction in aquatic organisms. However, molecular response triggered by Cu have remained largely unknown in freshwater prawn Macrobrachium rosenbergii. In the present study, we performed transcriptomic analysis to characterize molecular mechanisms of copper immunotoxicity in gills from M. rosenbergii. A large number of potential simple sequence repeats (SSRs) and single nucleotide polymorphisms (SNPs) loci in the transcriptome were identified. 19,417 and 8989 differentially expressed genes (DEGs) were obtained at 3 h and 48 h after exposure, respectively. Most of these DEGs were down-regulated implying that gene expressions were largely inhibited by Cu, which might lead to impairments of biological functions. Functional enrichment analysis of these DEGs revealed that immune, detoxification and apoptosis were the differentially regulated processes by Cu stress. 12 DGEs involved in immune response and heavy metal detoxification were discovered and validated by qRT-PCR. The results indicated that the M. rosenbergii might counteract the toxicity of Cu at the transcriptomic level by increasing expressions of immune- and heavy metal detoxification-related genes, and these selected genes could be used as molecular indicators for Cu stress. Our study firstly reported the stress response at transcriptional level in M. rosenbergii during Cu exposure. The genes and pathways identified here not only give us new insight into molecular mechanisms underlying Cu toxicity effects in prawn, but facilitate biomarker identification and stress-resistant breeding studies.


Assuntos
Cobre/toxicidade , Brânquias/efeitos dos fármacos , Palaemonidae/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Água Doce , Perfilação da Expressão Gênica , Metais Pesados/toxicidade , Transcriptoma/fisiologia
15.
Ecotoxicol Environ Saf ; 181: 49-59, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31170649

RESUMO

N-acetylcysteine (N-Acetyl L-cysteine, NAC) is a thiol compound derived from the addition of the acetyl group to cysteine amino acid. NAC has been used as an antioxidant, free radical scavenger, and chelating agent for reducing the deleterious effects on plants of biotic and abiotic environmental stresses. It can also relieve heavy metal (HM) toxicity, although its alleviating mechanism remains unknown. In this study, we compared HM-stressed (Cu, Hg, Cd and Pb, 100 µM each) wheat seedlings without NAC treatment and in combination with NAC (1 mM). In comparison to HMs alone, NAC treatment in combination with HMs (Cu, Cd, Hg and Pb, respectively) stimulated root growth (1.1-, 1.5-, 10.5- and 1.9-fold), and significantly increased fresh (1.3-, 1.5-, 4.3- and 1.4-fold) and dry (1.2-, 1.5-, 2.5- and 1.2-fold) mass. Combination treatment also led to significant reductions in HM concentrations (1.3-, 1.4-, 4- and 1.1-fold, respectively). GSH (1.1 - 1.8-fold), TBARS (1.4 - 2.7-fold) and H2O2 (1.6 - 1.8-fold) contents in treatment with HMs alone were significantly mitigated by the NAC combination. Some of the antioxidant enzyme activities increased or reduced by some HM treatments alone were stimulated by a combination of NAC with HMs, or remained unchanged or changed only insignificantly, supported by the phenolic pool of the plant. Ferulic, p-comaric and syringic acids were the major phenolic acids (PAs) in the roots in free, ester, glycoside and ester-bound forms, and their concentrations were increased by HM treatments alone, in comparison to the control seedlings, while PAs concentrations were relatively reduced by NAC in combination with HMs. These results indicate that NAC can alleviate HM toxicity and improve the growth of HM-stressed wheat seedlings by coordinated induction of the phenolic pool and the antioxidant defence system.


Assuntos
Acetilcisteína/farmacologia , Antioxidantes/farmacologia , Metais Pesados/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Poluentes do Solo/toxicidade , Triticum/efeitos dos fármacos , Peróxido de Hidrogênio/metabolismo , Hidroxibenzoatos/metabolismo , Plântula/efeitos dos fármacos , Plântula/enzimologia , Plântula/crescimento & desenvolvimento , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Triticum/enzimologia , Triticum/crescimento & desenvolvimento
16.
Ecotoxicol Environ Saf ; 181: 78-88, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31176250

RESUMO

Cultivation on selective media revealed that the oil-sorbents, wheat straw, corncobs and sugarcane bagasse harbor hydrocarbonoclastic, diazotrophic and heavy metal-resistant microorganisms. Nitrogen-free media containing 1.0% crude oil lost between 32.2 and 37.5% of this oil, after 8 months when they have been inoculated with such microorganism-loaded sorbents. The used wheat straw, corncobs and sugarcane bagasse samples, 1.0 g each, absorbed respectively, 1.9, 1.1 and 2.5 g oil samples, and lost 24.3-39.2% of these amounts, after they had been incubated for 8 months. Total genomic DNA's from culture media and sorbents revealed various nitrogenase-coding nifH-genes. Pure hydrocarbonoclastic microbial isolates tolerated certain concentrations of, Hg2+, Cd2+, Pb2+, AsO43- and AsO33-. Some of those isolates even grew excellently with up to 1000 ppm of Pb2+ and 36,000 ppm of AsO43- also in the presence of oil. Tested strains removed the tested heavy metals, Hg2+, Cd2+ and Pb2+ from the media and thus, reduced their toxicity against the hydrocarbon-degraders. It was concluded that plant-based sorbents, not only remove oil physically, but also harbor microbial communities effective in spilled oil-bioremediation under multiple stresses. Although each community consisted of one to three species only, the consortia which reached in numbers millions of CFU ml-1 enrich the oily media with fixed nitrogen, and remove heavy metals which otherwise inhibit the oil-degrading microorganisms.


Assuntos
Metais Pesados/toxicidade , Microbiota , Nitrogênio/metabolismo , Poluição por Petróleo/análise , Plantas , Adsorção , Biodegradação Ambiental , Hidrocarbonetos/química , Microbiota/efeitos dos fármacos , Modelos Teóricos , Fixação de Nitrogênio/efeitos dos fármacos , Plantas/química , Plantas/microbiologia , Resíduos Sólidos
17.
Environ Sci Pollut Res Int ; 26(23): 23615-23624, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31203538

RESUMO

The contamination of combined urban and rural area is a growing environmental issue due to rapid industrialization in China. This study investigated the eight potentially toxic elements (PTEs) arsenic (As), lead (Pb), cadmium (Cd), mercury (Hg), chromium (Cr), copper (Cu), nickel (Ni), and zinc (Zn) in paddy fields in a combined urban and rural area in Shaoxing city, Zhejiang province. Concentrations of the PTEs were determined in 60 topsoil samples (0-20 cm) collected from paddy fields in a combined urban and rural area in Shaoxing city, Zhejiang province, southeast China. The average contents of Pb, Cu, Zn, Cd, Hg, and As in the paddy soils increased by 23.7, 6.9, 17.0, 79.8, 62.5, and 47.9%, respectively, relative to their corresponding natural background concentrations. The mean contents of Cr and Ni did not exceed their background values. Multivariate statistical and geostatistical methods were used to distinguish between the PTEs (Cd, As, Pb, Zn, and Hg) contaminating the soils of the study area from those (Cr, Cu, and Ni) at background concentrations. About 17.2% of the soils were moderately polluted with PTEs as a result of urbanization. The results may be useful to policy makers in agricultural and urban management.


Assuntos
Monitoramento Ambiental , Poluentes do Solo/toxicidade , Agricultura , Arsênico , China , Cidades , Poluição Ambiental/análise , Mercúrio , Metais Pesados/análise , Metais Pesados/toxicidade , Oryza , Medição de Risco , Solo , Poluentes do Solo/análise , Zinco
18.
Mar Pollut Bull ; 144: 275-286, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31179997

RESUMO

In this study the Polychaeta Marphysa sanguinea, was tested to investigate the impact of metal pollution on the environmental state of a coastal Mediterranean lagoon, Tunis Lagoon (Tunisia). A multi-biomarker approach comprising glutathione-stransferase, cyclooxygenase, lysozyme activity, and lipid class composition of the Polychaeta was employed on a seasonal basis in the present investigation. The multivariate statistical approach (principal component analysis and Pearson correlation) clearly demonstrated different spatial patterns in biomarker values and lipid class concentrations. The phospholipids were the dominant lipid class in M. sanguinea, with the highest value found at the control station. The impact of pollution was most clearly observed on the main storage lipid class, triacylglycerol, which was lowest in the most impacted sites. Our work suggests that M. sanguinea can be used in warmer Mediterranean costal habitats as a sentinel species of contaminated ecosystems.


Assuntos
Monitoramento Ambiental/métodos , Lipídeos/química , Metais Pesados/análise , Poliquetos/efeitos dos fármacos , Oligoelementos/análise , Poluentes Químicos da Água/análise , Animais , Antioxidantes/metabolismo , Ecotoxicologia , Biomarcadores Ambientais/efeitos dos fármacos , Mar Mediterrâneo , Metais Pesados/toxicidade , Poliquetos/enzimologia , Poliquetos/metabolismo , Estações do Ano , Análise Espaço-Temporal , Oligoelementos/toxicidade , Tunísia , Poluentes Químicos da Água/toxicidade
19.
Life Sci ; 231: 116585, 2019 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-31226415

RESUMO

Exposure to environmental toxicants (ET) results in specific organ damage and auto-immune diseases, mostly mediated by inflammatory responses. The NLRP3 inflammasome has been found to be the major initiator of the associated pathologic inflammation. It has been found that ETs can trigger all the signals required for an NLRP3-mediated response. The exaggerated activation of the NLRP3 inflammasome and its end product IL-1ß, is responsible for the pathogenesis caused by many ETs including pesticides, organic pollutants, heavy metals, and crystalline compounds. Therefore, an extensive study of these chemicals and their mechanisms of inflammasome (INF) activation may provide the scientific evidence for possible targeting of this pathway by proposing possible protective agents that have been previously shown to affect INF compartments and its activation. Melatonin and polyunsaturated fatty acids (PUFA) are among the safest and the most studied of these agents, which affect a wide variety of cellular and physiological processes. These molecules have been shown to suppress the NLRP3 inflammasome mostly through the regulation of cellular redox status and the nuclear factor-κB (NF-κB) pathway, rendering them potential promising compounds to overcome ET-mediated organ damage. In the present review, we have made an effort to extensively review the ETs that exert their pathogenesis via the stimulation of inflammation, their precise mechanisms of action and the possible protective agents that could be potentially used to protect against such toxicants.


Assuntos
Inflamassomos/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Animais , Ecotoxicologia/métodos , Poluentes Ambientais/toxicidade , Humanos , Inflamação/metabolismo , Inflamação/patologia , Interleucina-1beta/metabolismo , Melatonina/metabolismo , Metais Pesados/administração & dosagem , Metais Pesados/efeitos adversos , Metais Pesados/toxicidade , NF-kappa B/metabolismo , Oxirredução , Praguicidas/toxicidade , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais
20.
Environ Sci Pollut Res Int ; 26(20): 20853-20865, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31111390

RESUMO

Urban areas under the influence of multi-industrial activities with arid and semi-arid environments witness the significant increase in environmental pollution especially in the water sector. The present study evaluated the water quality and associated health risk assessment through heavy metal pollution. Drinking (n = 48) and surface (n = 37) water samples were collected from semi-arid multi-industrial metropolis, Faisalabad, Pakistan. Physio-chemical and biological parameters and different metals (Al, As, Ba, Cd, Cr, Cu, Fe, Pb, Ni and Zn) were investigated using standard procedures and multivariate water quality assessments. Many physio-chemical and biological parameters and metals especially arsenic were exceeding the permissible limit of Punjab environmental quality standards and the World Health Organization. The results from water quality index showed that < 56% samples have poor, < 8% have very poor and < 6% have unsuitable water quality for drinking purposes. Water quality for the Gugera Branch Canal was found suitable with medium sodium (alkalinity) and salinity hazards, while it was found poor with magnesium absorption ratio. Hazard quotient (HQ) values for arsenic were found at the threshold level (HQ > 1) and carcinogenicity was found in case of arsenic and chromium (1 × 10-4) in adults and children. Semi-arid weather combined with different anthropogenic activities and unusual water features provoked metal contamination. Results of the present study can deliver basic information for effective management of water in the most populous and industrial areas.


Assuntos
Medição de Risco/métodos , Poluentes Químicos da Água/análise , Qualidade da Água , Adulto , Arsênico/análise , Arsênico/toxicidade , Carcinógenos/análise , Carcinógenos/toxicidade , Criança , Cidades , Exposição Dietética/efeitos adversos , Água Potável , Água Doce/análise , Humanos , Indústrias , Metais Pesados/análise , Metais Pesados/toxicidade , Paquistão , Poluentes Químicos da Água/toxicidade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA