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1.
Mar Pollut Bull ; 151: 110781, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32056582

RESUMO

The aim of the present study was to evaluate the presence of polycyclic aromatic hydrocarbons (PAHs) in oysters (Crassostrea rhizophorae) collected from Todos os Santos Bay (Bahia, Brazil). The total PAH concentration was highest in Madre de Deus (36.3 to 37.8 ng g-1 in dry weight, dw), which is located near a petrochemical complex, oil refinery, and commercial port. In the Paraguaçu river estuary, PAH concentrations varied between 23.2 and 25.7 ng g-1 dw. The lowest concentrations (1.55 ng g-1 dw) were found in the Jaguaribe river estuary, which can be considered a relatively preserved area. The main source of PAHs in the study areas was observed to be pyrogenic. Values of benzo[a]pyrene toxic equivalent ranged from 0.28 to 4.20. The concentrations of PAHs in oysters from the Paraguaçu river estuary and in Madre de Deus indicate the possible lifetime risk of developing cancer in humans who feed on it.


Assuntos
Monitoramento Ambiental , Ostreidae/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Baías , Brasil , Sedimentos Geológicos , Humanos , Rios
2.
Chem Biol Interact ; 315: 108905, 2020 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-31765606

RESUMO

Mineral oils are widely applied in food production and processing and may contain polycyclic aromatic hydrocarbons (PAHs). The PAHs that may be present in mineral oils are typically alkylated, and have been barely studied. Metabolic oxidation of the aromatic ring is a key step to form DNA-reactive PAH metabolites, but may be less prominent for alkylated PAHs since alkyl substituents would facilitate side chain oxidation as an alternative. The current study investigates this hypothesis of preferential side chain oxidation at the cost of aromatic oxidation using naphthalene and a series of its alkyl substituted analogues as model compounds. The metabolism was assessed by measuring metabolite formation in rat and human liver microsomal incubations using UPLC and GC-MS/MS. The presence of an alkyl side chain markedly reduced aromatic oxidation for all alkyl-substituted naphthalenes that were converted. 1-n-Dodecyl-naphthalene was not metabolized under the experimental conditions applied. With rat liver microsomes for 1-methyl-, 2-methyl-, 1-ethyl-, and 2-ethyl- naphthalene, alkyl side chain oxidation was preferred over aromatic oxidation. With human liver microsomes this was the case for 2-methyl-, and 2-ethyl-naphthalene. It is concluded that addition of an alkyl substituent in naphthalene shifts metabolism in favor of alkyl side chain oxidation at the cost of aromatic ring oxidation. Furthermore, alkyl side chains of 6 or more carbon atoms appeared to seriously hamper and reduce overall metabolism, metabolic conversion being no longer observed with the C12 alkyl side chain. In summary, alkylation of PAHs likely reduces their chances of aromatic oxidation and bioactivation.


Assuntos
Alquilantes/metabolismo , Microssomos Hepáticos/metabolismo , Naftalenos/metabolismo , Alquilação/fisiologia , Animais , Cromatografia Gasosa/métodos , Cromatografia Líquida de Alta Pressão/métodos , Humanos , Oxirredução , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Ratos , Espectrometria de Massas em Tandem/métodos
3.
Sci Total Environ ; 703: 135551, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31767300

RESUMO

Ten grouper species grouper (n = 584) were collected throughout the Gulf of Mexico (GoM) from 2011 through 2017 to provide information on hepatobiliary polycyclic aromatic hydrocarbon (PAH) concentrations in the aftermath of the Deepwater Horizon (DWH) oil spill. Liver and bile samples were analyzed for PAHs and their metabolites using triple quadrupole mass spectrometry (GC/MS/MS) and high-performance liquid chromatography with fluorescence detection (HPLC-F), respectively. Data were compared among species and sub-regions of the GoM to understand spatiotemporal exposure dynamics in these economically and ecologically important species. Significant differences in the composition and concentrations of PAHs were detected spatially, over time and by species. The West Florida Shelf, Cuba coast and the Yucatan Shelf had a greater proportion of the pyrogenic PAHs in their livers than the other regions likely due to non-oil industry related sources (e.g., marine vessel traffic) in the regional composition profiles. Mean liver PAH concentrations were highest in the north central region of the GoM where DWH occurred. Biliary PAH concentrations and health indicator biometrics initially decrease during the first three years following the DWH oil spill but significantly increased thereafter. Increased exposures are likely explained by the resuspension of residual DWH oil as well as continued inputs from natural (e.g., seeps) sources and other anthropogenically derived sources (e.g., riverine runoff, other oil spills, and leaking oil and gas infrastructure). The increasing trend in PAH concentrations in the bile and liver of grouper species in the north central region of the GoM post-DWH suggest continued chronic exposures, however the critical stage at which permanent, irreparable damage may occur is unknown. Long-term monitoring of PAH levels and associated fish health biomarkers is necessary to evaluate impacts of chronic exposures, particularly in regions subject to intensive oil extraction activities.


Assuntos
Monitoramento Ambiental , Peixes/fisiologia , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Golfo do México , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Testes de Toxicidade Crônica , Poluentes Químicos da Água/toxicidade
4.
Environ Pollut ; 256: 113487, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31679876

RESUMO

Halogenated polycyclic aromatic hydrocarbon (HPAH) concentrations in tissues from three tuna species Thunnus albacares (yellowfin tuna), Katsuwonus pelamis (skipjack tuna), and Auxis thazard (frigate tuna) were determined by high-resolution gas chromatography Orbitrap mass spectrometry. The tuna samples were collected from the Indian Ocean. The instrument conditions gave high mass accuracy at 0.9 m/z isolation width of the mass filter and a mass error of <±1.0 ppm for many HPAHs. A total of 29 of the 30 targets chlorinated PAHs (ClPAHs) and 20 of the 21 targets brominated PAHs (BrPAHs) were detected in the tuna muscle samples. The mean total ClPAH, BrPAH and PAH concentrations for tuna were 127.2, 156.6 and 682.8 ng/g lipid weight, respectively. The mean total ClPAH and BrPAH concentrations (ng/g lipid weight) in the tuna were considerably lower than that of PAH concentrations. The mean total ClPAH, BrPAH and PAH concentrations in T. albacares respectively were 185.8, 249.2 and 784.1 ng/g lipid weight, irrespective of the body sizes. The mean total ClPAH, BrPAH and PAH concentrations in K. pelamis respectively were 45.1, 24.8 and 555.6 ng/g lipid weight. The mean total ClPAH, BrPAH and PAH concentrations in A. thazard respectively were 34.09, 4.73 and 433.24 ng/g lipid weight. The total ClPAH concentrations and body weights significantly positively correlated for T. albacares. The mean total ClPAH concentration in white muscles was significantly higher (p < 0.05) for large than for small T. albacares. This suggests ClPAHs could bioaccumulate in T. albacares, possibly because they are poorly metabolized. The chlorinated phenanthrene and pyrene concentrations indicated tuna accumulate these compounds increasingly effectively as the tuna grow. This was the first time large numbers of HPAHs were found in biological samples. HPAHs may adversely affect the health of humans consuming tuna.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Atum/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Monitoramento Ambiental , Cromatografia Gasosa-Espectrometria de Massas , Halogenação , Oceano Índico , Músculos/química , Fenantrenos , Hidrocarbonetos Policíclicos Aromáticos/análise
5.
Toxicol Lett ; 321: 114-121, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31830554

RESUMO

Despite numerous studies on the toxicities of planar polycyclic aromatic hydrocarbons (PAHs), very little is known about the toxicological profiles of non-planar PAHs. In the present study, the cytotoxicity of corannulene (COR), a typical bowl-shaped PAH with a myriad of applications in the area of material chemistry, and benzo[a]pyrene (BaP), a typical planar PAH with similar molecular weight, were systematically compared in various cell lines. Compared with BaP, exposure to COR resulted in less cytotoxic responses in both human (HepG2) and murine (Hepa1-6) hepatoma cells, which was characterized with a slower cellular accumulation as well as a weaker induction of cytochrome P450 1 (CYP1/Cyp1) isozymes. Knockdown of aryl hydrocarbon receptor (AhR) by siRNA attenuated the inductive effect of COR on CYP1A/Cyp1a mRNA levels in these two cell lines. Further analysis revealed that derivatization greatly influenced the cytotoxicity of COR, which was positively correlated with their binding affinities to the AhR, as demonstrated by in silico molecular docking. Overall, these results suggest that AhR appears to be involved in the cytotoxic responses of COR and its derivatives, providing a fundamental understanding of the biological effects of bowl-like PAHs.


Assuntos
Fatores de Transcrição Hélice-Alça-Hélice Básicos/agonistas , Hepatócitos/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Receptores de Hidrocarboneto Arílico/agonistas , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Sítios de Ligação , Citocromo P-450 CYP1A1/biossíntese , Citocromo P-450 CYP1A1/genética , Indução Enzimática , Células Hep G2 , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Camundongos , Simulação de Acoplamento Molecular , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Ligação Proteica , Conformação Proteica , Receptores de Hidrocarboneto Arílico/genética , Receptores de Hidrocarboneto Arílico/metabolismo , Transdução de Sinais , Relação Estrutura-Atividade
6.
Ecotoxicol Environ Saf ; 190: 110092, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31874406

RESUMO

Integrated chemical-biological treatment is a promising alternative to remove PAHs from contaminated soil, wherein indigenous bacteria is the key factor for the biodegradation of residual PAHs after the application of chemical oxidation. However, systematical study on the impact of persulfate (PS) oxidation on indigenous bacteria as well as PAHs removal is still scarce. In this study, the influences of different PS dosages (1%, 3%, 6%, and 10% [w/w]), as well as various activation methods (native iron, H2O2, alkaline, ferrous iron, and heat) on PAHs removal and indigenous bacteria in highly contaminated aged soil were investigated. Apparent degradation of PAHs in the soil treated with PS oxidation was observed, and the removal efficiency of total PAHs in the soil ranged from 38.28% to 79.97%. The removal efficiency of total PAHs in the soil increased with increasing consumption of PS. However, the bacterial abundance in soil was negatively affected following oxidation for all of the treatments added with PS, with bacterial abundance in the soil decreased by 0.89-2.93 orders of magnitude compared to the untreated soil. Moreover, the number of total bacteria in the soil decreased as PS consumption increased. Different PS activation methods and PS dosages exhibited different influences on the bacterial community composition. Bacteria capable of degrading PAHs under anoxic conditions were composed predominantly by Proteobacteria and Firmicutes. The total amount of Proteobacteria and Firmicutes also decreased with increasing consumption of PS. The results of this study provide important insight for the design of PAHs contaminated soil remediation projects.


Assuntos
Bactérias/metabolismo , Biodegradação Ambiental , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Peróxido de Hidrogênio/metabolismo , Ferro/química , Oxirredução , Hidrocarbonetos Policíclicos Aromáticos/análise , Solo/química , Poluentes do Solo/análise
7.
Chemosphere ; 239: 124796, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31520972

RESUMO

In July 2013, a fatal train derailment led to an explosion and fire in the town of Lac-Mégantic (LM), Quebec, and the crude oil contamination of regional surface water, soil, and sediment in the adjacent Lake Mégantic. This study investigated the degradation potential of the spilled crude oil by using the sediments from the incident site as the source of microorganisms. Two light crude oils (LM source oil and Alberta Sweet Mixed Blend (ASMB)) were tested at 22 °C for 4 weeks and 4 °C for 8 weeks, respectively. The post-incubation biological and chemical information of the samples were analysed. There was no marked difference in degradation efficacy and biological activities for both the LM and ASMB oils, although the biodegradation potential differed between the two incubations. Higher temperature favoured the growth of microorganisms, thus for the degradation of all petroleum hydrocarbons, except for some conservative biomarkers. The degradation of both oils followed the order of resolved components > total saturated hydrocarbons (TSH) > unresolved complex mixture (UCM) >total aromatic hydrocarbons (TAH). Normal alkanes were generally degraded more significantly than branched ones, and polycyclic aromatic hydrocarbons (PAHs). Degradation of polycyclic aromatic hydrocarbons (PAHs) and their alkylated congeners (APAHs) for both incubations generally decreased as the number of aromatic rings, and the degree of alkylation increased. This study showed that the LM sediments can biodegrade the petroleum hydrocarbons efficaciously if appropriate ambient temperatures are generated to favour the growth of autochthonous microorganisms.


Assuntos
Sedimentos Geológicos/microbiologia , Hidrocarbonetos/química , Hidrocarbonetos/metabolismo , Petróleo/metabolismo , Poluentes Químicos da Água/metabolismo , Alcanos/química , Alcanos/metabolismo , Biodegradação Ambiental , Lagos/microbiologia , Poluição por Petróleo , Hidrocarbonetos Policíclicos Aromáticos/química , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Quebeque , Temperatura Ambiente , Poluentes Químicos da Água/química
8.
Rev Environ Contam Toxicol ; 251: 25-108, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31011832

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are a class of hazardous organic contaminants that are widely distributed in nature, and many of them are potentially toxic to humans and other living organisms. Biodegradation is the major route of detoxification and removal of PAHs from the environment. Aerobic biodegradation of PAHs has been the subject of extensive research; however, reports on anaerobic biodegradation of PAHs are so far limited. Microbial degradation of PAHs under anaerobic conditions is difficult because of the slow growth rate of anaerobes and low energy yield in the metabolic processes. Despite the limitations, some anaerobic bacteria degrade PAHs under nitrate-reducing, sulfate-reducing, iron-reducing, and methanogenic conditions. Anaerobic biodegradation, though relatively slow, is a significant process of natural attenuation of PAHs from the impacted anoxic environments such as sediments, subsurface soils, and aquifers. This review is intended to provide comprehensive details on microbial degradation of PAHs under various reducing conditions, to describe the degradation mechanisms, and to identify the areas that should receive due attention in further investigations.


Assuntos
Bactérias Anaeróbias/metabolismo , Biodegradação Ambiental , Poluentes Ambientais/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Nitratos
9.
J Environ Sci (China) ; 86: 97-106, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31787194

RESUMO

Knowledge on methanogenic microbial communities associated with the degradation of polycyclic aromatic hydrocarbons (PAHs) is crucial to developing strategies for PAHs bioremediation. In this study, the linkage between the type of PAHs and microbial community structure was fully investigated through 16S rRNA gene sequencing on four PAH-degrading cultures. Putative degradation products were also detected. Our results indicated that naphthalene (Nap)/2-methylnaphthalene (2-Nap), phenanthrene (Phe) and anthracene (Ant) sculpted different microbial communities. Among them, Nap and 2-Nap selected for similar degrading bacteria (i.e., Alicycliphilus and Thauera) and methanogens (Methanomethylovorans and Methanobacterium). Nap and 2-Nap were probably activated via carboxylation, producing 2-naphthoic acid. In contrast, Phe and Ant shaped different bacterial and archaeal communities, with Arcobacter and Acinetobacter being Phe-degraders and Thiobacillus Ant-degrader. Methanogenic archaea Methanobacterium and Methanomethylovorans predominated Phe-degrading and Ant-degrading culture, respectively. These findings can improve our understanding of natural PAHs attenuation and provide some guidance for PAHs bioremediation in methanogenic environment.


Assuntos
Microbiota , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes do Solo/metabolismo , Archaea , Bactérias , Biodegradação Ambiental , Crescimento Quimioautotrófico , Euryarchaeota
10.
Sheng Wu Gong Cheng Xue Bao ; 35(11): 2069-2080, 2019 Nov 25.
Artigo em Chinês | MEDLINE | ID: mdl-31814355

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) cause enormous environmental hazards that threaten human health. Bacterial degradation of PAHs has been extensively studied. Bacteria enhanced their biodegradability through multiple levels of regulatory analysis and adaptive evolution to produce diverse catabolic pathways. Based on recent developments, we address here the research progress in bioremediation technology to degrade low molecular weight polycyclic aromatic hydrocarbons.


Assuntos
Biodegradação Ambiental , Hidrocarbonetos Policíclicos Aromáticos , Bactérias/metabolismo , Peso Molecular , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Pesquisa/tendências
11.
Environ Monit Assess ; 191(11): 700, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31667668

RESUMO

The distribution of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the muscle, liver, spleen and kidney tissue of two fish species was studied using an optimised diatomaceous earth assisted modified QuEChERS extraction method. Five-year-old free-ranging male African sharptooth catfish (Clarias gariepinus) and 5-year-old male common carp (Cyprinus carpio) sampled from the Hartbeespoort Dam in South Africa were used for method development. Acetonitrile extraction produced more precise recoveries than hexane extraction. Fluorene and naphthalene were the most abundant PAHs detected in the majority of fish tissues analysed. PAH bioaccumulation in 5-year-old carp and 5-year-old catfish was in the order muscle > kidney > liver > spleen and liver > muscle > kidney > spleen, respectively. PCBs were mostly detected in carp spleen and kidney. Two-year-old carp were analysed to determine PCB and PAH bioaccumulation trends. The differences in ∑16PAH concentrations between the four organs tested were all statistically insignificant for the 3 fish tested (p > 0.05). All other organs with the exception of 5-year-old carp spleen and 5-year-old carp kidney recorded total 31 PCB concentrations (∑31PCB) < 25 ng g-1. Only 5-year-old carp spleen (∑31PCB of 592 ng g-1) and 5-year-old carp kidney (∑31PCB of 561 ng g-1) had significant differences (p < 0.05) from the spleen and kidney in 5-year-old catfish and 2-year-old carp. Whilst the carp and catfish sampled can be considered low PCB risk foods, 5-year-old carp muscle can be considered to be a high PAH risk food, with a benzo(a)pyrene concentration of 7 µg g-1, based on the EU Commission Regulation 2005/208/EC pertaining to the maximum permissible benzo(a)pyrene level in fresh fish muscle.


Assuntos
Carpas/metabolismo , Peixes-Gato/metabolismo , Monitoramento Ambiental , Bifenilos Policlorados/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Bioacumulação , Peixes-Gato/fisiologia , Fígado/metabolismo , Masculino , Músculos/química , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , África do Sul
12.
Environ Pollut ; 255(Pt 2): 113135, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31550651

RESUMO

The Fort McMurray region in northeastern Alberta (Canada) is rich in natural sources of polycyclic aromatic compounds (PACs) from exposed bitumen beds; anthropogenic sources are being released with increased oil sands industry expansion. Here we report on investigations of PACs (47 compounds) in three species of forage fish collected during the 2012-2013 Joint Oil Sands Monitoring Program (JOSMP) fish health investigations and compare results with PAC data for sediment and water collected under JOSMP and earlier programs. PAC concentrations in sediments varied three orders in magnitude and were highest at downstream tributary mouths, which flowed through the exposed McMurray Formation, and along reaches of the Athabasca River where the formation was exposed. PAC concentrations in water were less variable but with higher concentrations near exposed bitumen beds. Forage fish exhibited the weakest spatial gradients in ΣPACs concentration, which averaged 102 ±â€¯32 ng/g in trout-perch from the Athabasca River, 125 ±â€¯22 ng/g in lake chub from the Ells River, and 278 ±â€¯267 ng/g in slimy sculpin from the Steepbank, Firebag, and Dunkirk Rivers. Low-molecular weight compounds, particularly naphthalenes and fluorenes, dominated fish PACs. Phenanthrenes occurred in greater percent composition in fish caught in areas where PAC concentrations in sediments were higher due to the proximity of bitumen sources than in other areas. Dibenzothiophene, a major component of bitumen PAC, was a minor component of fish ΣPACs. Forage fish PAC concentrations were below fish consumption guidelines established by the European Commission (2011) and for the reopening of the commercial fisheries closed by the Deepwater Horizon oil spill. PAC concentrations in forage fish were similar to concentrations observed in many other studies (fish market surveys, estuaries, and marine waters) and lower than in fish sampled from highly impacted areas (near refineries, harbors, and other industrialized areas).


Assuntos
Monitoramento Ambiental , Peixes/metabolismo , Campos de Petróleo e Gás , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes Químicos da Água/metabolismo , Alberta , Animais , Carga Corporal (Radioterapia) , Hidrocarbonetos , Poluição por Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Compostos Policíclicos , Rios , Areia , Poluentes Químicos da Água/análise
13.
Ecotoxicol Environ Saf ; 184: 109591, 2019 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-31514081

RESUMO

Restoring polluted sites by petroleum hydrocarbons is a challenge because of their complexity and persistence in the environment. The main objective of the present study was to investigate the performance of plant-actinobacteria system for the remediation of crude petroleum and pure-polycyclic aromatic hydrocarbons (PAHs) contaminated soils. The endophytic strain Streptomyces sp. Hlh1 was tested for its ability to degrade model PAHs (phenanthrene, pyrene and anthracene) in liquid minimal medium. Streptomyces sp. Hlh1 demonstrated the ability to grow on PAHs as sole carbon and energy source, reaching hydrocarbons removal of 63%, 93% and 83% for phenanthrene, pyrene and anthracene, respectively. Maize plant was chosen to study the impact of Streptomyces sp. Hlh1 inoculation on the dissipation of contaminants and plant growth. Thus, maize seedlings grown in soils contaminated with crude petroleum and pure-PAHs were inoculated with Streptomyces sp. Hlh1. Results showed that the endophyte inoculation increased contaminants removal. Maximum hydrocarbons removal (70%) was achieved in inoculated and planted soil contaminated with crude oil, while 61%, 59%, and 46% of hydrocarbons dissipation were registered for phenanthrene, pyrene and anthracene, respectively. These degradations rates were significantly higher compared to non-inoculated systems in all the treatments evaluated. Further, it was revealed that hydrocarbons (C8-C30) were efficiently degraded in plant-Streptomyces Hlh1 system. Moreover, the inoculation with the actinobacteria resulted significant plant development and enhanced photosynthetic pigments compared to plants grown in the other experimental conditions. The present study provide evidence that the inoculation of maize plants with Streptomyces sp. Hlh1 play a remarkable role in the removal of petroleum hydrocarbons, enhancing plant development in contaminated soils.


Assuntos
Biodegradação Ambiental , Poluição por Petróleo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes do Solo/metabolismo , Streptomyces/metabolismo , Zea mays/microbiologia , Endófitos/metabolismo , Desenvolvimento Vegetal , Hidrocarbonetos Policíclicos Aromáticos/análise , Plântula/crescimento & desenvolvimento , Plântula/metabolismo , Plântula/microbiologia , Solo/química , Poluentes do Solo/análise , Zea mays/crescimento & desenvolvimento , Zea mays/metabolismo
14.
Environ Sci Pollut Res Int ; 26(30): 31449-31462, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31478172

RESUMO

Bioelectrochemical systems (BESs) have great potential for treating wastewater containing polycyclic aromatic hydrocarbons (PAHs); however, detailed data on cell physiological activities in PAH biodegradation pathways stimulated by BESs are still lacking. In this paper, a novel BES device was assembled to promote the growth of Pseudomonas sp. DGYH-12 in phenanthrene (PHE) degradation. The results showed that in the micro-electric field (0.2 V), cell growth rate and PHE degradation efficiency were 22% and 27.2% higher than biological control without electric stimulation (BC), respectively. The extracellular polymeric substance (EPS) concentration in BES (39.38 mg L-1) was higher than control (33.36 mg L-1); moreover, the membrane permeability and ATPase activities were also enhanced and there existing phthalic acid and salicylic acid metabolic pathways in the strain. The degradation genes nahAc, pcaH, and xylE expression levels were upregulated by micro-electric stimulation. This is the first study to analyze the physiological and metabolic effect of micro-electric stimulation on a PHE-degrading strain in detail and systematically.


Assuntos
Biodegradação Ambiental , Fenantrenos/metabolismo , Pseudomonas/metabolismo , Eliminação de Resíduos Líquidos/métodos , Estimulação Elétrica , Matriz Extracelular de Substâncias Poliméricas , Redes e Vias Metabólicas , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Águas Residuárias
15.
Appl Microbiol Biotechnol ; 103(19): 8145-8155, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31482283

RESUMO

The environmental accumulation of polycyclic aromatic hydrocarbons (PAHs) is of great concern due to potential carcinogenic and mutagenic risks, as well as their resistance to remediation. While many fungi have been reported to break down PAHs in environments, the details of gene-based metabolic pathways are not yet comprehensively understood. Specifically, the genome-scale transcriptional responses of fungal PAH degradation have rarely been reported. In this study, we report the genomic and transcriptomic basis of PAH bioremediation by a potent fungal degrader, Dentipellis sp. KUC8613. The genome size of this fungus was 36.71 Mbp long encoding 14,320 putative protein-coding genes. The strain efficiently removed more than 90% of 100 mg/l concentration of PAHs within 10 days. The genomic and transcriptomic analysis of this white rot fungus highlights that the strain primarily utilized non-ligninolytic enzymes to remove various PAHs, rather than typical ligninolytic enzymes known for playing important roles in PAH degradation. PAH removal by non-ligninolytic enzymes was initiated by both different PAH-specific and common upregulation of P450s, followed by downstream PAH-transforming enzymes such as epoxide hydrolases, dehydrogenases, FAD-dependent monooxygenases, dioxygenases, and glycosyl- or glutathione transferases. Among the various PAHs, phenanthrene induced a more dynamic transcriptomic response possibly due to its greater cytotoxicity, leading to highly upregulated genes involved in the translocation of PAHs, a defense system against reactive oxygen species, and ATP synthesis. Our genomic and transcriptomic data provide a foundation of understanding regarding the mycoremediation of PAHs and the application of this strain for polluted environments.


Assuntos
Basidiomycota/genética , Basidiomycota/metabolismo , Perfilação da Expressão Gênica , Genômica , Redes e Vias Metabólicas/genética , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Biotransformação
16.
Environ Sci Pollut Res Int ; 26(30): 31401-31413, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31485937

RESUMO

The effects of Fire Phoenix (a mixture of Festuca L.) and Purple coneflower (Echinacea purpurea (L.) Moench) on the remediation of two different high concentrations of PAH-contaminated soils were studied under the effect of strain N12 (Mycobacterium sp.), and the changes in rhizosphere enzymatic activity were preliminarily studied. The results of three culture stages (60 d, 120 d, and 150 d) showed that N12 has a promotional effect on the biomass of Fire Phoenix and E. purpurea, and the effect of N12 on the biomass of Fire Phoenix is better. Under the strengthening of N12, the maximum removal rates of Fire Phoenix reached 86.77% and 67.82% at two high PAH concentrations (A and B, respectively). The activity of dehydrogenase (DHO) is positively correlated with the degradation rate of PAHs at the A concentration (P < 0.05). The activity of DHO in soil will continue to increase at a higher level of the B concentration, but the positive correlation between the activity of DHO and the degradation rate of PAH is weakened. In the rhizosphere soil of the two plants, the change in polyphenol oxidase (PPO) activity with time has a significant negative correlation with the degradation rate of PAHs (P < 0.05). The experiment proved that Fire Phoenix is more suitable for the remediation of heavy PAH-contaminated soil under the condition of microorganism-strengthening, and it can achieve a better degradation effect when the concentrations of PAHs are < 150 mg·kg-1. Results provide a further scientific basis for the remediation of contaminated sites.


Assuntos
Biodegradação Ambiental , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes do Solo/metabolismo , Biomassa , Poluentes Ambientais , Festuca/metabolismo , Petróleo , Poluição por Petróleo , Hidrocarbonetos Policíclicos Aromáticos/análise , Rizosfera , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise
17.
Nat Commun ; 10(1): 3443, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31371724

RESUMO

Self-assembly of twelve pentatopic tectons, which have complementary edges or can be linked using either digonal or trigonal connectors, represents the optimal synthetic strategy to achieve spherical objects, such as chemical capsids. This process requires conditions that secure uninterrupted equilibria of binding and self-correction en route to the global energy minimum. Here we report the synthesis of a highly soluble, deca-heterosubstituted corannulene that bears five terpyridine ligands. Spontaneous self-assembly of twelve such tectons with 30 cadmium(II) cations produces a giant icosahedral capsid as a thermodynamically stable single product in high yield. Nuclear magnetic resonance (NMR) methods, mass spectrometry analyses, small-angle X-ray scattering, transmission electron microscopy, and atomic force microscopy indicate that this spherical capsid has an external diameter of nearly 6 nm and shell thickness of 1 nm, in agreement with molecular modeling. NMR and liquid chromatography evidences imply that chiral self-sorting complexation generates a racemic mixture of homochiral capsids.


Assuntos
Proteínas do Capsídeo/metabolismo , Capsídeo/química , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Montagem de Vírus/fisiologia , Antraquinonas , Cádmio/metabolismo , Modelos Moleculares , Termodinâmica
18.
Toxicol Lett ; 315: 64-76, 2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31419470

RESUMO

To test the hypothesis that 3-7 ring polycyclic aromatic hydrocarbons (PAHs) are responsible for the prenatal developmental toxicity (PDT) as observed with some petroleum substances (PS), the present study evaluates the PDT potency of DMSO-extracts of 7 heavy fuel oils (HFO), varying in their PAH content, and 1 highly refined base oil (HRBO), containing no aromatics, in the embryonic stem cell test (EST). All DMSO-extracts of HFO inhibit ES-D3 cell differentiation in a concentration-dependent manner and their potency is proportional to the amount of 3-7 ring PAHs they contain. All DMSO-extracts of HFOs also show aryl hydrocarbon receptor (AhR)-mediated activities, as tested in the AhR-CALUX assay. Contrarily, the HRBO-extract tested negative in both assays. Co-exposure of ES-D3 cells with selected DMSO-extracts of PS and the AhR-antagonist trimethoxyflavone, successfully counteracted the PS-induced inhibition of ES-D3 cell differentiation, confirming the role of the AhR in mediating the observed PDT of PS extracts in the EST. A good correlation exists when comparing the in-vitro with the in-vivo PDT potencies of the PS under study. Altogether, our findings corroborate the hypothesis that PS-induced PDT is caused by 3-7 ring PAHs present in these substances and that the observed PDT is partially AhR-mediated.


Assuntos
Células-Tronco Embrionárias/efeitos dos fármacos , Poluentes Ambientais/toxicidade , Petróleo/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Receptores de Hidrocarboneto Arílico/metabolismo , Bioensaio , Poluentes Ambientais/metabolismo , Feminino , Humanos , Petróleo/metabolismo , Gravidez
19.
Appl Microbiol Biotechnol ; 103(17): 7203-7215, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31256229

RESUMO

Since polycyclic aromatic hydrocarbons (PAHs) are mutagenic, teratogenic, and carcinogenic, they are of considerable environmental concern. A biotechnological approach to remove such compounds from polluted ecosystems could be based on the use of white-rot fungi (WRF). The potential of well-adapted indigenous Ganoderma strains to degrade PAHs remains underexplored. Seven native Ganoderma sp. strains with capacity to produce high levels of laccase enzymes and to degrade synthetic dyes were investigated for their degradation potential of PAHs. The crude enzymatic extracts produced by Ganoderma strains differentially degraded the PAHs assayed (naphthalene 34-73%, phenanthrene 9-67%, fluorene 11-64%). Ganoderma sp. UH-M was the most promising strain for the degradation of PAHs without the addition of redox mediators. The PAH oxidation performed by the extracellular enzymes produced more polar and soluble metabolites such as benzoic acid, catechol, phthalic and protocatechuic acids, allowing us to propose degradation pathways of these PAHs. This is the first study in which breakdown intermediates and degradation pathways of PAHs by a native strain of Ganoderma genus were determined. The treatment of PAHs with the biomass of this fungal strain enhanced the degradation of the three PAHs. The laccase enzymes played an important role in the degradation of these compounds; however, the role of peroxidases cannot be excluded. Ganoderma sp. UH-M is a promising candidate for the bioremediation of ecosystems polluted with PAHs.


Assuntos
Poluentes Ambientais/metabolismo , Ganoderma/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Biodegradação Ambiental , Fluorenos/metabolismo , Ganoderma/enzimologia , Lacase/metabolismo , Naftalenos/metabolismo , Oxirredução , Peroxidases/metabolismo , Fenantrenos/metabolismo
20.
Environ Sci Pollut Res Int ; 26(24): 25154-25166, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31256397

RESUMO

This study evaluated an enhancement of simultaneous polycyclic aromatic hydrocarbon (PAH) biodegradation and lipid accumulation by Rhodococcus opacus using biochar derived cheaply from biomass gasification effluent. The chemical, physical, morphological, thermal, and magnetic properties of the cheaply derived biochar were initially characterized employing different techniques, which indicated that the material is easy to separate, recover, and reuse for further application. Batch experiments were carried out to study biochar-aided PAH biodegradation by R. opacus clearly demonstrating its positive effect on PAH biodegradation and lipid accumulation by the bacterium utilizing the synthetic media containing 2-, 3- or 4-ring PAH compounds, at an initial concentration in the range 50-200 mg L-1, along with 10% (w/v) inoculum. An enhancement in PAH biodegradation from 79.6 to 92.3%, 76.1 to 90.5%, 74.1 to 88.2%, and 71.6 to 82.3% for naphthalene, anthracene, phenanthrene, and fluoranthene, respectively, were attained with a corresponding lipid accumulation of 68.1%, 74.2%, 72.4%, and 63% (w/w) of cell dry weight (CDW). From contact angle measurements carried out in the study, enhancement in PAH biodegradation and lipid accumulation due to the biochar was attributed to an improved bioavailability of PAH to the degrading bacterium.


Assuntos
Lipídeos/química , Naftalenos/química , Fenantrenos/química , Hidrocarbonetos Policíclicos Aromáticos/química , Rhodococcus/química , Biodegradação Ambiental , Biomassa , Carvão Vegetal , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Rhodococcus/metabolismo
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