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1.
Ecotoxicol Environ Saf ; 208: 111621, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396141

RESUMO

The study explored the polycyclic aromatic hydrocarbon tolerance of indigenous biosurfactant producing microorganisms. Three bacterial species were isolated from crude oil contaminated sites of Haldia, West Bengal. The three species were screened for biosurfactant production and identified by 16S rRNA sequencing as Brevundimonas sp. IITISM 11, Pseudomonas sp. IITISM 19 and Pseudomonas sp. IITISM 24. The strains showed emulsification activities of 51%, 57% and 63%, respectively. The purified biosurfactants were characterised using FT-IR, GC-MS and NMR spectroscopy and found to have structural similarities to glycolipopeptides, cyclic lipopeptides and glycolipids. The biosurfactants produced were found to be stable under a wide range of temperature (0-100 °C), pH (4-12) and salinity (up to 20% NaCl). Moreover, the strains displayed tolerance to high concentrations (275 mg/L) of anthracene and fluorene and showed a good amount of cell surface hydrophobicity with different hydrocarbons. The study reports the production and characterisation of biosurfactant by Brevundimonas sp. for the first time. Additionally, the kinetic parameters of the bacterial strains grown on up to 300 mg/L concentration of anthracene and fluorene, ranged between 0.0131 and 0.0156 µmax (h-1), while the Ks(mg/L) ranged between 59.28 and 102.66 for Monod's Model. For Haldane-Andrew's model, µmax (h-1) varied between 0.0168 and 0.0198. The inhibition constant was highest for Pseudomonas sp. IITISM 19 on anthracene and Brevundimonas sp. IITISM 11 on fluorene. The findings of the study suggest that indigenous biosurfactant producing strains have tolerance to high PAH concentrations and can be exploited for bioremediation purposes.


Assuntos
Antracenos/metabolismo , Biodegradação Ambiental , Fluorenos/metabolismo , Tensoativos/metabolismo , Antracenos/química , Bactérias/metabolismo , Fluorenos/química , Glicolipídeos , Hidrocarbonetos/metabolismo , Cinética , Petróleo/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Pseudomonas/metabolismo , RNA Ribossômico 16S/metabolismo , Espectroscopia de Infravermelho com Transformada de Fourier , Tensoativos/química
2.
Ecotoxicol Environ Saf ; 208: 111586, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396109

RESUMO

This research studies a typical landscape of an agricultural area separated from the road by a ditch with trees. Soils were sampled at 1, 2, 7, 25, and 50 m from the road. The concentrations of polycyclic aromatic hydrocarbons (PAH), total and phyto-available heavy metals (HM), total petroleum hydrocarbons (TPH), and de-icing salts (DS, Cl-) were determined using standard techniques. A set of higher plants (Lepidium sativum L., Sinapis alba L., Raphanus sativus L., Hordeum vulgare L., Avena sativa L.) was applied for toxicity evaluation of soils. The objective of this research is to find correlations between pollution of roadside soils and their phytotoxicity. HM, TPH and DS contamination of soils was observed in the 0-25 m zone, and PAH contamination was found up to the 50 m. Soil toxicity was declining from the road to the 50 m. Phytotoxicity related to majority of plants performed correlations with the same set of contaminants: TPH, 2-rings PAH, phyto-available Zn, Cu, Pb, and total Zn. No any correlations demonstrated Avena sativa L., being not applicable for ecotoxicological assessment of roadside soils. Despite the phytotoxicity was generally in line with contaminants loads, surprisingly low values were indicated in the ditch characterized by the strong pollution. We attribute this to the contrasting properties of soils there - the higher content of organics and clay. Sensitivity of plants to roadside pollution decreased in the row Lepidium sativum L. > Hordeum vulgare L. > Sinapis alba L. > Raphanus sativus L. The most reliable test-parameters for toxicity estimation were the root and the shoot length, germination rate was not informative indicating low phytotoxicity values. The research showed the importance of the right choice of test-cultures and test-parameters to judge phytotoxicity correctly. Linking the contaminants loads and phytotoxicity effects is valuable for comprehensive ecotoxicological assessment.


Assuntos
Plantas/efeitos dos fármacos , Poluentes do Solo/toxicidade , Agricultura , Ecotoxicologia , Monitoramento Ambiental/métodos , Poluição Ambiental , Hordeum , Hidrocarbonetos , Lepidium sativum , Metais Pesados/análise , Petróleo/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Sinapis , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise
3.
Ecotoxicol Environ Saf ; 208: 111592, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396115

RESUMO

Accidental spills are pervasive pollution in aquatic ecosystems. Resorting to chemical dispersant is one of the most implemented strategies in response to oil spills, but it results in an increase in the bio-availability of oil compounds known to disturb fish neurosensory capacities and hence fish habitat use. While it has become well established that acute oil exposure can cause a range of physiological defects, sub-lethal consequences on animal behaviour have only received recent attention. Here we investigated the effect of an exposure to a 62 h- dispersant treated oil on the exploration tendency (exploratory activity, and avoidance of unfamiliar open areas) of juvenile European sea bass. Three different concentrations of chemically dispersed oil were tested, low and medium conditions bracketing the range of likely situations that fish encounter following an oil spill, the high dose representing a more severe condition. Fish recovery capacities were also evaluated during 2 weeks post-exposure. Our results suggest a dose-response relationship; the low dose (0.048 ± 0.007 g L-1 of total petroleum hydrocarbons ([TPH])) had no effect on sea bass behavioural response to a novel environment while medium (0.243 ± 0.012 g L-1 [TPH]) and high (0.902 ± 0.031 g L-1 [TPH]) doses altered fish exploratory activity and their typical avoidance of unfamiliar open areas. Our experiment also suggest signs of recovery capacities in the first 10 days following oil exposure even if fish might need more time to fully recover from observed alterations. We discuss the possibility that observed alterations may result from a neurosensory or physiological known defects of oil exposure, causing anaesthetic-like sedative behaviours. Altogether, this study shows that juvenile sea bass exposed to oil spill exhibit transient behavioural impairments that may have major population-level consequences given the high mortality experienced by juveniles.


Assuntos
Bass/fisiologia , Poluição por Petróleo , Poluentes Químicos da Água/toxicidade , Animais , Ecossistema , Comportamento Exploratório , Hidrocarbonetos , Petróleo , Poluentes Químicos da Água/análise
4.
Sci Total Environ ; 753: 142250, 2021 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-33207468

RESUMO

This article provides a comprehensive review on aerobic composting remediation of soil contaminated with total petroleum hydrocarbons (TPHs). The studies reviewed have demonstrated that composting technology can be applied to treat TPH contamination (as high as 380,000 mg kg-1) in clay, silt, and sandy soils successfully. Most of these studies reported more than 70% removal efficiency, with a maximum of 99%. During the composting process, the bacteria use TPHs as carbon and energy sources, whereas the fungi produce enzymes that can catalyze oxidation reactions of TPHs. The mutualistic and competitive interactions between the bacteria and fungi are believed to sustain a robust biodegradation system. The highest biodegradation rate is observed during the thermophilic phase. However, the presence of a diverse and dynamic microbial community ensures that TPH degradation occurs in the entire composting process. Initial concentration, soil type, soil/compost ratio, aeration rate, moisture content, C/N ratio, pH, and temperature affect the composting process and should be monitored and controlled to ensure successful degradation. Nevertheless, there is insufficient research on optimizing these operational parameters, especially for large-scale composting. Also, toxic and odorous gas emissions during degradation of TPHs, usually unaddressed, can be potential air pollution sources and need further insightful characterization and mitigation/control research.


Assuntos
Compostagem , Petróleo , Poluentes do Solo , Biodegradação Ambiental , Hidrocarbonetos , Solo , Microbiologia do Solo
5.
J Environ Manage ; 277: 111480, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33045647

RESUMO

A halotolerant strain CO100 of Staphylococcus sp. was isolated from contaminated sediments taken from the fishing harbour of Sfax, Tunisia, as an efficient hydrocarbonoclastic candidate. Strain CO100 exhibited a high capacity to break down almost 72% of the aliphatic hydrocarbons contained in crude oil (1%, v/v), used as the sole carbon and energy source, after 20 days of culture, at 100 g/l NaCl, 37 °C and 180 rpm. The isolate CO100 displayed also its ability to grow on phenanthrene, fluoranthene and pyrene (100 mg/l), at 100 g/l NaCl. Moreover, the isolate CO100 showed a notable aptitude to synthesize an efficient tensioactive agent namely BS-CO100, on low-value substrates including residual frying oil and expired milk powder, thus reducing the high cost of biosurfactant production. The ESI/MS analysis designated that BS-CO100 belonged to lipopeptide class, in particular lichenysin and iturine members. Critical micelle concentrations of BS-CO100 were varying between 65 and 750 mg/l, depending on of the purity of the biosurfactant and the used carbon sources. BS-CO100 showed a high steadiness against a wide spectrum of pH (4.3-12), temperature (4-121 °C) and salinity (0-300 g/l NaCl), supporting its powerful tensioactive properties under various environmental conditions. Likewise, BS-CO100 exhibited no cytotoxic effect toward human HEK293 cells, at concentrations within 125 and 1000 µg/ml. Furthermore, the biosurfactant BS-CO100 exhibited remarkable anti-adhesive and anti-biofilm activities, being able to avoid and disrupt the biofilm formation by certain pathogenic microorganisms. In addition, BS-CO100 was found to have more potential to remove hydrocarbons from contaminated soils, compared to some chemical surfactants. In light of these promising findings, strain CO100, as well as its biosurfactant, could be successfully used in different biotechnological applications including the bioremediation of oil-polluted areas, even under saline conditions.


Assuntos
Petróleo , Staphylococcus , Biodegradação Ambiental , Células HEK293 , Humanos , Hidrocarbonetos , Tensoativos , Tunísia
6.
Chemosphere ; 263: 128382, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297285

RESUMO

As an ecotoxicological tool, bioassays are an effective screening tool to eliminate plants sensitive to the contaminant of interest, and thereby reduce the number of plant species requiring further study. We conducted a bioassay analysis of fifteen plant species to determine their tolerance to diesel fuel toxicity. Dose-response analysis revealed that increasing diesel fuel concentrations in the soil generally led to a monotonically decreasing biomass in 13 species (P < 0.001), with EC10 values (±SE) ranging from 0.36 ± 0.18 g/kg to 12.67 ± 2.13 g/kg. On the other hand, hydrocarbons had a statistically significant hormetic influence on Medicago sativa (f = 3.90 ± 1.08; P < 0.01). The EC10 and EC50 values (±SE) from the fitted hormetic model were 15.33 ± 1.47 g/kg and 26.89 ± 2.00 g/kg, respectively. While previous studies have shown M. sativa's tolerance of hydrocarbon toxicity, this is the first attempt to describe diesel fuel-induced hormesis in M. sativa using the Cedergreen-Ritz-Streibig model. This study thus shows that hormesis cannot be ignored in plant toxicology research, and that when present, an appropriate statistical model is necessary to avoid drawing wrong conclusions.


Assuntos
Gasolina , Poluentes do Solo , Gasolina/toxicidade , Hidrocarbonetos , Plantas , Solo , Poluentes do Solo/análise , Poluentes do Solo/toxicidade
7.
Chemosphere ; 264(Pt 1): 128377, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33017706

RESUMO

The present study integrated the electrokinetic (EK) with bioremediation (Bioelectrokinetic -BEK) of diesel hydrocarbon by Staphylococcus epidermidis EVR4. It was identified as efficient biosurfactant producing bacteria and growth parameters was optimized using response surface methodology. Upon degradation, there is a complete disappearance of peaks from nonane (C9) to tricosane (C23) and 85%, 47% of degradation of pentacosane and octacosane respectively. Marine bacterial strain, EVR4 was found to be potential to degrade the diesel with a maximum degradation efficiency of 96% within 4 d, which was due to its synergistic role of biosurfactant and catabolic enzymes (dehydrogenase, catalase and cytochrome C). The application of integrated BEK was an effective insitu method for the remediation of diesel contaminated soil by BEK (84%) than EK (67%). EVR4 as an effective strain can be employed for BIO-EK method to clean the diesel hydrocarbon polluted environment.


Assuntos
Poluentes do Solo , Bactérias , Biodegradação Ambiental , Hidrocarbonetos , Solo , Microbiologia do Solo , Poluentes do Solo/análise
8.
Chemosphere ; 264(Pt 2): 128521, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33039688

RESUMO

An innovative mesophilic aerobic biopile technology was explored to improve the bioremediation efficiency of petroleum-contaminated soil. Under the suitable soil conditions (C:N:P at 100:5:1 and soil moisture content at 18%), the soil pH was hold in the range of 7.4 to 6.8 throughout the bioremediation process, the mesophilic (30 °C-40 °C) and forced aeration (3 h-on/1 h-off) conditions were the critical factors to enhancing petroleum biodegradation. The consumption of bioavailable organic carbon (BAC) which was one of the most important factors regulating microbial metabolism, was positively related (R2 = 0.85, 40 °C) with the rate of petroleum removal. The 50% threshold of BAC could be regarded as the signal for supplementing the soil nutrients in the mesophilic aerobic biopiles to favor petroleum removal. The optimal conditions (40 °C, 3 h-on/1 h-off) maximized the utilization of BAC, promoted the petroleum degradation, and remained the microbial abundance and community composition stable to the greatest extent. In addition, the accumulation of aliphatic acids affected the microbial activity, which limited the efficiency of petroleum degradation to a certain extent. Jointly considering the energy consumption, time cost and soil conditions maintenance, a cost-effective biopile technology was obtained by temperature and aeration regulation and BAC supplementation, which could be applied to engineering application.


Assuntos
Petróleo , Poluentes do Solo , Biodegradação Ambiental , Carbono , Hidrocarbonetos , Solo , Microbiologia do Solo , Poluentes do Solo/análise
9.
Bioresour Technol ; 319: 124240, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33254463

RESUMO

This study was aimed at remediation ofoily waste contaminated area by utilizing a newly obtained bacterium. For experimental setup three different approachessuch as bioaugmentation, natural attenuation and abiotic factors were employed. In bioaugmented experimental set up (treatment withP. aeruginosaNCIM 5514),76.14 ± 0.85% loss in oily waste with notable hydrocarbon utilizers was noted in 56 days. From the results, it was concluded that bioaugmentation with novel P. aeruginosasp. (oily waste degrader) could remediate oily waste pollution effectively. Results of this study demonstrate applicability of P. aeruginosa NCIM 5514 for environmental sustainability.


Assuntos
Petróleo , Poluentes do Solo , Biodegradação Ambiental , Poluição Ambiental , Hidrocarbonetos , Pseudomonas aeruginosa , Microbiologia do Solo
10.
J Environ Manage ; 278(Pt 1): 111410, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33113394

RESUMO

Until the complete transition to a renewable energy sources based economy, the potential environmental hazards associated with petroleum refinery industries affecting water, air and soil seek sustainable solutions. In the present study contaminated soil from a refinery is used as an alternative source for producing useful building materials by geopolymerization. To this end, soil remediation by thermal desorption was initially applied. Thermal treatment was performed between 60 and 250 °C for short time intervals (10-30 min) in order to remove organic pollutants (Total Petroleum Hydrocarbons, TPHs and Polycyclic Aromatic Hydrocarbons, PAHs). Physical, chemical analyses, mineral phase composition, as well as thermogravimetric analysis were employed to characterize the sample. Moreover, removal efficiency of TPHs and PAHs was evaluated. Subsequently, the treated soil presenting the maximum elimination of TPH and PAHs was used in geopolymer mortar formation aiming to stabilize the toxic metals (TMs) and produce a possible profitable material. For geopolymer synthesis the substitution of metakaolin (MT) by treated soil at 0, 50, 70 and 100% was tested. The produced specimens were evaluated based on the 28 day compressive strength and metals leaching. Results showed that the geopolymer constructed by 50% MT-50% remediated soil at 250 °C for 30 min, had negligible content of organic pollutants, TMs were immobilized and exhibited increased strength thus giving significant recycling benefits. Valorisation of industrial residues to produce building materials is a promising solution for sustainable waste management.


Assuntos
Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Hidrocarbonetos , Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Solo , Poluentes do Solo/análise
11.
Chemosphere ; 262: 128352, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33182087

RESUMO

As organic pollution of soil and groundwater increases, the effective and economical remediation of contaminated sites has drawn growing attention. In this study, running-water (RW) was designed to modify alkali-heat/persulfate (MAH/PS) for integrated remediation of an actual organic-contaminated site. The degradation efficiency mainly reached 60%-99% for Benz[a]anthracene, Benzo[a]pyrene and total petroleum hydrocarbons (TPHs). MAH/PS was more effective in degrading Benzene and 1,2-Dichloroethane with simple molecular configurations. The pollutant degradation efficiencies decreased with increasing site depth and increased with increasing pollutant concentrations. Migration with RW enhanced site remediation. By monitoring the groundwater after remediation, it was found that residual TPHs presented anomalous diffusion; SO42- ranged from 8.00 to 237.00 mg L-1 to 8.00-290.00 mg L-1 and pH presented alkalescence (7.00-8.20). Mathematical models were established to describe the reaction process including the solubility equilibrium of calcium hydroxide, temperature equilibrium, and reaction kinetics. Moreover, MAH/PS provided a cost-saving approach for site remediation.


Assuntos
Recuperação e Remediação Ambiental/métodos , Poluentes do Solo/análise , Poluentes do Solo/química , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/química , Álcalis , Benzo(a)pireno/química , China , Água Subterrânea/análise , Água Subterrânea/química , Temperatura Alta , Hidrocarbonetos/química , Modelos Teóricos , Oxirredução , Petróleo/análise , Poluição por Petróleo , Solo/química , Sulfatos/química
12.
Sci Total Environ ; 754: 142174, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32916498

RESUMO

This study aims to investigate the effect of microwave torrefaction and ZSM-5 catalyst for hydrocarbon rich bio-oil production from microwave co-pyrolysis of cellulose and low density polyethylene (LDPE). FTIR analysis displayed remarkable reductions of active hydroxyl and ether groups in microwave torrefied cellulose (MTC), demonstrating that cellulose was less stable than MTC. GC/MS analysis indicated that the hydrocarbons content was ranged from 18.36% to 54.94% in the obtained bio-oils under different conditions, and the maximum hydrocarbons content (54.94%) which also contained the highest aromatic hydrocarbons (19.49%) was obtained from MTC catalytic co-pyrolysis. Microwave-assisted Thermogravimetric analyzer (MW-TGA) analysis showed that MTC catalytic co-pyrolysis apparently shifted the major thermal degradation to a lower temperature area, an evident synergistic effect was observed during MTC catalytic co-pyrolysis. Kinetics study revealed that the activation energy was significantly reduced from 97.87 kJ/mol to 63.86 kJ/mol for co-pyrolysis and MTC catalytic co-pyrolysis, respectively.


Assuntos
Celulose , Pirólise , Biocombustíveis , Biomassa , Catálise , Calefação , Temperatura Alta , Hidrocarbonetos , Micro-Ondas , Óleos Vegetais , Polietileno , Polifenóis
13.
Sci Total Environ ; 751: 141720, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32882554

RESUMO

Freshwater lake ecosystem is a reservior of valuable microbial diversity. It needs to be explored for addressing key environmental issues like petroleum-hydrocarbon contamination. In this work, the microbial communities (pre and post enriched with petroleum-hydrocarbons) from different layers of freshwater lake, i.e. surface water, sediments and deepwater, were explored through metagenomic and culture-dependent approaches. A total of 41 bacterial phyla were retrieved from pre-enriched samples, which were significantly reduced in enriched samples where Proteobacteria were dominant (87% to 100%) followed by Bacteroidetes (7.37%) and Verrucomicrobia (3.06%). The most dominant hydrocarbon-degrading genera were extensively verified as Pseudomonas (48.65%), Acinetobacter (45.38%), Stenotrophomonas (3.16%) and Brevundimonas (2.07%) in surface water (S1WCC); Acinetobacter (62.46%), Aeromonas (10.7%), Sphingobacterium (5.20%) and Pseudomonas (4.23%) in sediment (S2MCC); and Acinetobacter (46.57%), Pseudomonas (13.10%), Comamonas (12.93%), Flavobacterium (12.18%) and Enterobacter (9.62%) in deep water (S4WCC). Additionally, the maximum biodegradation of petroleum-hydrocarbons (i.e. used engine oil or UEO) was achieved by microbiome of S2MCC (67.60 ± 0.08%) followed by S4WCC (59.70 ± 0.12%), whereas only 36.80 ± 0.10% degradation was achieved by S1WCC microbiome. On the other hand, UEO degradation by cultivable biosurfactant-producing single cultures such as Pseudomonas sp. S2WE, Pseudomonas sp. S2WG, Pseudomonas sp. S2MS, Ochrobactrum sp. S1MM and Bacillus nealsonii S2MT showed 31.10 ± 0.08% to 40.50 ± 0.11% biodegradation. Comparatively, the biodegradation efficiency was found higher (i.e. 42.20 ± 0.12% to 56.10 ± 0.12%) in each consortia comprising of two, three, four, and five bacterial cultures. Conclusively, the isolated culturable biosurfactants-producing bacterial consortium of freshwater lake demonstrated >80% contribution in the total petroleum-hydrocarbons degradation by the natural microbiome of the ecosystem.


Assuntos
Microbiota , Petróleo , Bacillus , Biodegradação Ambiental , Hidrocarbonetos , Lagos
14.
Ecotoxicol Environ Saf ; 208: 111394, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33031985

RESUMO

The development of oil and gas production together with the fruit production in nearby areas of North Patagonia, Argentina, suggests aquatic pollution scenarios which include permanent oil pollution combined with short events of pesticides application. It has been reported that oil hydrocarbons activate the aryl hydrocarbon receptor (AhR) pathway in the rainbow trout, Oncorhynchus mykiss, and that the insecticide Chlorpyrifos (CPF) interacts with these effects. Thus, it is interesting to investigate whether hydrocarbons and insecticides, applied by separate or combined, can affect fish health and reproductive signaling by acting on different nuclear receptors' regulatory pathways. To study this kind of interactions, we exposed juvenile rainbow trout to water accommodated fraction (WAF) of crude oil (62 µg L-1 TPH) for 48 h and subsequently exposed the livers ex vivo to the insecticide Chlorpyrifos (CPF) (20 µg L-1) for 1 h. We analyzed the mRNA expression of nuclear receptors and proteins involved in detoxifying, antioxidant, immune and apoptosis responses by qRT-PCR. We also performed histopathological analysis. WAF induced the expression of the androgen (AR) and the Liver X receptor (LXR) by 8- and 3-fold, respectively. AR induction was reversed by subsequent exposure to CPF. The progesterone receptor (PR) and glucocorticoid receptor (GR) were increased 2-fold and 3-fold by WAF respectively, while estrogen and mineralocorticoid receptors were not affected. GR was also induced by CPF with an additive effect in the WAF-CPF treatment. The antioxidant genes, gamma glutamyl transferase (GGT), superoxide dismutase (SOD1) were induced by WAF (2-3-fold). WAF upregulated the ATP Binding Cassette Subfamily C Member 2 (ABCC2, MRP2) (4-fold) and downregulated alkaline phosphatase. WAF also induced the inflammatory interleukins (IL) IL-8, and IL-6 and the anti-inflammatory IL-10, while CPF induced the inflammatory tumor necrosis factor (-α) and IL-6, and activated the intrinsic apoptotic pathway through the induction of caspases 3 and 9. Both, WAF and CPF downregulated the expression of the extrinsic apoptosis initiator caspase 8 and the inflammatory caspase 1. In conclusion, WAF hydrocarbons alter O. mykiss endocrine regulation by inducing AR, PR and GR. The subsequent exposure to CPF reverses AR, suggesting a complex interaction of different pollutants in contaminated environments, WAF hydrocarbons alter liver metabolism by inducing the expression of LXR, GR, antioxidant and detoxifying enzymes, and both inflammatory and anti-inflammatory cytokines, and causing mild hepatic steatosis. CPF activates inflammatory and stress responses associated with the induction of inflammatory cytokines together with apoptosis initiator and executioner caspases.


Assuntos
Clorpirifos/toxicidade , Hidrocarbonetos/toxicidade , Oncorhynchus mykiss/fisiologia , Poluentes Químicos da Água/toxicidade , Animais , Antioxidantes/metabolismo , Argentina , Clorpirifos/metabolismo , Hidrocarbonetos/metabolismo , Imunidade , Inseticidas/toxicidade , Fígado/efeitos dos fármacos , Petróleo/metabolismo , Poluição por Petróleo , Receptores Citoplasmáticos e Nucleares/metabolismo , Poluentes Químicos da Água/metabolismo
15.
Ecotoxicol Environ Saf ; 207: 111514, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33254394

RESUMO

The present study investigated the stability and efficacy of a biosurfactant produced by Klebsiella sp. KOD36 under extreme conditions and its potential for enhancing the solubilization and degradation of phenanthrene in various environmental matrices. Klebsiella sp. KOD36 produced a mono-rhamnolipids biosurfactant with a low critical micelle concentration (CMC) value. The biosurfactant was stable under extreme conditions (60 °C, pH 10 and 10% salinity) and could lower surface tension by 30% and maintained an emulsification index of > 40%. The emulsion index was also higher (17-43%) in the presence of petroleum hydrocarbons compared to synthetic surfactant Triton X-100. Investigation on phenanthrene degradation in three different environmental matrices (aqueous, soil-slurry and soil) confirmed that the biosurfactant enhanced the solubilization and biodegradation of phenanthrene in all matrices. The high functional stability and performance of the biosurfactant under extreme conditions on phenanthrene degradation show the great potential of the biosurfactant for remediation applications under harsh environmental conditions.


Assuntos
Biodegradação Ambiental , Klebsiella/fisiologia , Fenantrenos/metabolismo , Tensoativos/metabolismo , Meios de Cultura , Emulsões , Glicolipídeos , Hidrocarbonetos/metabolismo , Klebsiella/metabolismo , Micelas , Petróleo/metabolismo , Solo , Poluentes do Solo/metabolismo
16.
Ecotoxicol Environ Saf ; 207: 111551, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33254409

RESUMO

Oil spills have an important threat to the ecological security and human health, for example the important oil field and coastal wetland Yellow River Delta is facing the dual problems of oil pollution and salinization. Therefore, the purpose of this study was to analyze the changes of soil microbial community and physicochemical properties, including pH value, total organic carbon (TOC), total petroleum hydrocarbons (TPHs) and electrical conductivity under the combined effect of petroleum and salinization. The soil properties results showed that the petroleum addition promoted the increase of TOC from 2.31 ± 0.59 mg/kg to 7.04 ± 0.42 mg/kg (r > 0.95, P < 0.1, R2 > 0.9), TPHs from 9.18 ± 0.07 mg/kg to 33.09 ± 4.61 mg/kg (r > 0.9, P < 0.05, R2 > 0.9) significantly. At the initial stage hydrocarbons caused the increase of soil salt content and the decrease of pH. Salt addition increased soil salt from 2.46 ± 0.13 g/kg to 15.12 ± 0.21 g/kg (r > 0.8, P > 0.1, R2 > 0.95), but it had no direct effect on other soil properties. It was found that the nitrate reducing bacteria Halorhodospiraceae with potential petroleum degradation ability and the anaerobic bacteria Lactobacilliceae appeared after adding crude oil. The salt tolerant bacteria Halobacilli and the stone oil degrading bacteria Immundisolidcharacter appeared in the high salt and low salt environments respectively. The aerobic bacteria Acidimicrobiaceae, Hyphomonas and the nonoil efficient Peptoccaceae disappeared in the process of salinization and oil pollution. Lactobacilliceae can ferment carbohydrate, fatty acid or ester to produce lactic acid, acetic acid and fumaric acid to provide metabolic substrate for other microorganisms. The above results showed that sensitive microorganisms were easy to be affected by pollution to indicate soil conditions, while tolerant microorganisms could potentially use oil to achieve bioremediation. The soil properties and microbial results provided data support and theoretical basis for further understanding the pollution mechanism of oil and salinization combined stress on soil.


Assuntos
Biodegradação Ambiental , Poluição por Petróleo , Microbiologia do Solo , Poluentes do Solo/análise , Bactérias/metabolismo , China , Poluentes Ambientais/metabolismo , Hidrocarbonetos/análise , Microbiota , Petróleo/análise , Rios , Solo/química , Áreas Alagadas
17.
Ecotoxicol Environ Saf ; 207: 111554, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33254411

RESUMO

Toxicity monitoring of environmental pollutants especially petroleum hydrocarbons as priority pollutants is an important environmental issue. This study addresses a rapid, sensitive and cost effective method for the detection of total petroleum hydrocarbons (TPHs) using Aliivibrio fischeri bioluminescence inhibition bioassay. At the first step, the optimum conditions including time, pH and temperature for growth of A. fischeri were determined. Then, two methods were used to evaluate the toxicity of petroleum compounds. In the first method, short-term (15 min) and long-term (16 h) toxicity assays were performed. In the second method luminescence kinetics of A. fischeri was investigated during 24 h. The results demonstrated the most appropriate time for the bacterial growth occurred 16 h after inoculation and optimum temperature and pH were found 25 °C and 7, respectively. Short-term and long-term toxicity did not indicate any toxicity for various concentrations of TPHs (30, 50, 110, 160, 220 mg/L). Considering the luminescence kinetics of A. fischeri the long-term assay was introduced as 6 h. The half maximal effective concentration (EC50) was achieved 1.77 mg/L of TPHs. It is concluded that the luminescence kinetics of A. fischeri can be a valuable approach for assessing toxicity of TPHs in aquatic environments.


Assuntos
Aliivibrio fischeri/efeitos dos fármacos , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade , Bioensaio/métodos , Poluentes Ambientais/toxicidade , Hidrocarbonetos/toxicidade , Luminescência , Medições Luminescentes
18.
J Environ Manage ; 280: 111648, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33213993

RESUMO

Sewage sludge digestate is a valuable organic waste which can be used as fertilizer in soil bioremediation. Sewage sludge digestate is not only a good source of nutrients but is also rich in bacteria carrying alkB genes, which are involved in aliphatic hydrocarbons metabolism. Increase of alkB genes ratio in polluted soils has been observed to improve bioremediation efficiency. In this study, for the first time, the genetic potential of indigenous microorganisms of digestate to degrade petroleum products was assessed. The objectives were to study petroleum hydrocarbons (PHCs) removal together with shifts in soil taxa and changes in the concentration of alkB genes after digestate application. Initial alkB genes concentration in contaminated soils and digestate was 1.5% and 4.5%, respectively. During soil incubation with digestate, alkB genes percentage increased up to 11.5% and after the addition of bacteria immobilized onto biochar this value increased up to 60%. Application of digestate positively affected soil respiration and bacterial density, which was concomitant with enhanced PHCs degradation. Incubation of soil amended with digestate resulted in 74% PHCs decrease in 2 months, while extra addition of bacteria immobilized onto biochar increased this value up to 95%. The use of digestate affected the microbial community profiles by increasing initial bacterial density and diversity, including taxa containing recognized PHCs degraders. This study reveals the great potential of digestate as a soil amendment which additionally improves the abundance of alkB genes in petroleum contaminated soils.


Assuntos
Petróleo , Poluentes do Solo , Biodegradação Ambiental , Hidrocarbonetos , Petróleo/análise , Esgotos , Solo , Microbiologia do Solo , Poluentes do Solo/análise
19.
J Environ Manage ; 280: 111650, 2021 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-33213994

RESUMO

In this study, application of risk assessment was the basis for the selection of an optimum treatment option for the potential bioremediation of a hydrocarbon polluted environment. This approach was applied in a hydrocarbon polluted swampy terrain in the Niger Delta of Nigeria and could actually be applied to any other hydrocarbon polluted environment. Three nutrient sources namely compost, liquid organic fertilizer and NPK were employed in the laboratory biostimulation of the biodegradation of the hydrocarbons experiments using three levels of concentration for each nutrient as 5, 10 and 20% (w/w). Total petroleum hydrocarbon (TPH) and polycyclic aromatic hydrocarbons (PAH) were the analytes used in assessing the biodegradation potential of the various treatments. The residual concentration of these analytes post biodegradation was measured by means of gas chromatography-flame ionization detector and gas chromatography-mass spectrometry. Results indicate that compost and liquid organic fertilizer at 5% (w/w) were very poor in biostimulating the biodegradation of the hydrocarbons (less than 20% biodegradation of TPH and 3-30% biodegradation of the PAHs). NPK performed better than the other two sources of nutrients as it effected 74-84% TPH biodegradation and 39-90% PAHs biodegradation. On screening the three NPK treatment options using risk assessment, the 5% w/w NPK treatment option was rejected as its associated residual PAHs posed risks that exceeded the risk threshold of 10^-6 whereas the other two (10 and 20% w/w NPK) were successful with risk values less than the threshold. However, the 10% w/w NPK treatment offers a cheaper option between the two hence it is selected as the optimum bioremediation option based on risk management.


Assuntos
Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Biodegradação Ambiental , Hidrocarbonetos , Níger , Nigéria , Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Medição de Risco , Microbiologia do Solo , Poluentes do Solo/análise
20.
Chemosphere ; 263: 128081, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33297080

RESUMO

Distribution and elimination of petroleum products can be predicted in aerobic wastewater treatment plants (WWTPs) using models such as multimedia fate model SimpleTreat. An advantage of the SimpleTreat model is that it only requires a few basic properties of a chemical in wastewater to calculate partitioning, biodegradation and ultimately emissions to air, surface water and produced sludge. The SimpleTreat model structure reflects a WWTP scheme. However, refinery WWTPs typically incorporate more advanced treatment processes such as dissolved air flotation (DAF), a process that clarifies wastewaters by the removal of suspended matter such as oil or solids. The objective of this work was to develop a WWTP removal model that includes DAF treatment. To understand how including a DAF in the model affects the predicted concentrations of petroleum constituents in effluent, we replaced the primary sedimentation module in SimpleTreat with a module simulating DAF. Subsequently, we compared results from the WWTP-DAF model with results obtained with the original SimpleTreat model for a library of over 1500 representative hydrocarbon constituents. The increased air-water exchange in a WWTP-DAF unit resulted in higher predicted removal of volatile constituents. Predicted removal with DAF was on average 17% larger than removal with primary sedimentation. We compared modelled results with measured removal data from the literature, which supported that this model refinement continues to improve the technical basis of assessment of petroleum products.


Assuntos
Petróleo , Esgotos , Biodegradação Ambiental , Hidrocarbonetos , Eliminação de Resíduos Líquidos , Águas Residuárias
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