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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: 111673, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33396005

RESUMO

In the present research, a bioremediation process was developed using solid complex bacterial agents (SCBA) through a combined two-step biodegradation process. Four isolated strains showed high efficiency for the degradation of total petroleum hydrocarbons (TPH) and the reduction of COD of the oily sludge, at 96.6% and 92.6%, respectively. The mixed strains together with bran prepared in form of SCBA exhibited improved performance compared to individual strains, all of which had an optimal temperature of around 35 °C. The use of SCBA provided advantages over commonly used liquid media for storage and transportation. The two-step process, consisting of firstly biosurfactant-assisted oil recovery and secondly biodegradation of the remaining TPH with SCBA, demonstrated the capability for treating oily sludge with high TPH content (>10 wt%) and short process period (60 days). The large-scale (5 tons oily sludge) field test, achieving a TPH removal efficiency of 93.8% and COD reduction of 91.5%, respectively, confirmed the feasibility and superiority of the technology for industrial applications.


Assuntos
Microbiota , Poluição por Petróleo/prevenção & controle , Petróleo/análise , Esgotos , Biodegradação Ambiental , Meios de Cultura , Hidrocarbonetos/análise , Hidrocarbonetos/metabolismo , Petróleo/metabolismo , Poluição por Petróleo/análise , Esgotos/química , Esgotos/microbiologia , Temperatura
3.
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
4.
Artigo em Inglês | MEDLINE | ID: mdl-33378252

RESUMO

Petroleum hydrocarbons (PHCs) in petroleum refinery sludge (PRS) are the most adverse components because of their toxic nature, which are harmful to human health and the aquatic ecosystem. This study aimed to identify and characterize an indigenous bacterium isolated from PRS of Indian oil corporation ltd. (IOCL), Haldia, India, and evaluate its performance for biodegradation of total petroleum hydrocarbon (TPH) of PRS. The bacterium molecularly characterized as Stenotrophomonas sp. IRB19 by 16S rRNA sequencing and phylogenetic analysis. The strain IRB19 showed a significant ability to utilize four different oils (kerosene, diesel, petrol and hexadecane) in-vitro. IRB19 could able to degrade up to 65 ± 2.4% of TPH in 28 d of incubation. Solvent extraction study showed that PRS contain 180.57 ± 3.44 g kg-1 of TPH and maltene fraction composed of aliphatic, aromatics and polar components of 52 ± 4, 39 ± 2 and 9 ± 1%, respectively. The TPH degradation best fitted for the Gompertz model and followed the first-order kinetics having the rate constant (k) and half-life period (t 1/2) of 0.036 d-1 and 19 d, respectively. Results of this study verified the suitability of the novel strain IRB19 for the biodegradation of PHCs.


Assuntos
Petróleo/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Esgotos/microbiologia , Microbiologia do Solo , Poluentes do Solo/análise , Stenotrophomonas/crescimento & desenvolvimento , Biodegradação Ambiental , Ecossistema , Humanos , Índia , Modelos Teóricos , Petróleo/metabolismo , Filogenia , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , RNA Ribossômico 16S/genética , Esgotos/química , Poluentes do Solo/metabolismo , Stenotrophomonas/isolamento & purificação
5.
Appl Environ Microbiol ; 86(21)2020 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-32826215

RESUMO

The risk of petroleum spills coupled with the potential application of chemical dispersants as a spill response strategy necessitates further understanding of the fate of oil and dispersants and their interactive effects during biodegradation. Using Arctic seawater mesocosms amended with either crude oil, Corexit 9500, or both together, we quantified the chemical losses of crude oil and Corexit 9500 and identified microbial taxa implicated in their biodegradation based on shifts in the microbial community structure over a 30-day time course. Chemical analyses included total petroleum hydrocarbons (TPH), n-alkanes, branched alkanes, and polycyclic aromatic hydrocarbons (PAHs) for oil loss and the surfactant components dioctyl sodium sulfosuccinate (DOSS), Span 80, Tween 80, Tween 85, and the DOSS metabolite ethylhexyl sulfosuccinate (EHSS) for Corexit loss. Changes to the microbial communities and identification of key taxa were determined by 16S rRNA gene amplicon sequencing. The nonionic surfactants of Corexit 9500 (Span 80 and Tweens 80 and 85) biodegraded rapidly, dropping to below the limits of detection within 5 days and prior to any detectable initiation of oil biodegradation. This resulted in no observable suppression of petroleum biodegradation in the presence of Corexit compared to that of oil alone. In contrast, biodegradation of DOSS was delayed in the presence of oil, based on the prolonged presence of DOSS and accumulation of the degradation intermediate EHSS that did not occur in the absence of oil. Microbial analyses revealed that oil and Corexit enriched different overall microbial communities, with the presence of both resulting in a community composition that shifted from one more similar to that of Corexit only to one reflecting the oil-only community over time, in parallel with the degradation of predominantly Corexit and then oil components. Some microbial taxa (Oleispira, Pseudofulvibacter, and Roseobacter) responded to either oil or Corexit, suggesting that some organisms may be capable of utilizing both substrates. Together, these findings reveal interactive effects of crude oil and Corexit 9500 on chemical losses and microbial communities as they biodegrade, providing further insight into their fate when copresent in the environment.IMPORTANCE Chemical dispersants such as Corexit 9500 are commonly used in oil spill response and are currently under consideration for use in the Arctic, where their fate and effects have not been well studied. This research was performed to determine the interactive effects of the copresence of crude oil and Corexit 9500 on the degradation of components from each mixture and the associated microbial community structure over time in Arctic seawater. These findings will help yield a better understanding of the biodegradability of dispersant components applied to an oil spill, the temporal microbial community response to dispersed oil, and the fundamental microbial ecology of organic contaminant biodegradation processes in the Arctic marine environment.


Assuntos
Bactérias/metabolismo , Lipídeos , Microbiota , Petróleo/metabolismo , Regiões Árticas , Biodegradação Ambiental , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Água do Mar/microbiologia
6.
Ecotoxicol Environ Saf ; 205: 111103, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32818878

RESUMO

Oil pollution is a serious international concern due to its harmful effect on human health and the environment. This study aims to investigate the effective factors on the biodegradation of Iranian heavy crude oil by Bacillus licheniformis. For this purpose, oil removal from the artificial seawater was studied by response surface methodology (RSM). After the screening experiments, pH (4-10), NaCl concentration (0-10 g/L), and oil concentration (500-4500 ppm) were selected as influential factors. Moreover, to evaluate the bacterial capability in bioremediation of an actual polluted site, crude oil spill with a salinity of 35 g/L was experimentally simulated. The proposed model in this study clearly shows that both selected individual factors and their interactions are significantly effective on the crude oil biodegradation capacity. The results showed that Bacillus licheniformis was able to degrade crude oil at different concentrations of oil, especially at low concentrations, which are challenging in actual polluted sites. 15%-66% removal was achieved for 500-4500 ppm of crude oil after 14 days. Furthermore, according to the obtained results, this bacterium can tolerate the salinity up to 3.5%. At this salinity level, crude oil removal was 23.43 and 25.64% in neutral and alkaline conditions, respectively. Process factors were optimized, and 54.8% of crude oil was removed at optimum conditions i.e., 3500 ppm crude oil concentration, 2.5 g/L of NaCl and pH equal to 8.5. Finally, it can be concluded that the selected bacterium of this study can be more effective in harsh environments such as hypersaline and alkaline conditions.


Assuntos
Bacillus licheniformis/metabolismo , Poluição por Petróleo/análise , Petróleo/análise , Água do Mar/química , Poluentes Químicos da Água/análise , Biodegradação Ambiental , Irã (Geográfico) , Modelos Teóricos , Petróleo/metabolismo , Salinidade , Água do Mar/microbiologia , Poluentes Químicos da Água/metabolismo
7.
Arch Microbiol ; 202(8): 2189-2196, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32524179

RESUMO

Three hydrocarbon degrading microorganisms were isolated from the soil samples collected from the storage sites of low viscosity spindle oil containers and identified on the basis of morphological and biochemical characteristics as Aeromonas hydrophila, Bacillus subtilis and Staphylococcus aureus. The study has revealed high ability of these microorganisms for oil biodegradation. The results have indicated that all isolates had the potential to breakdown the hydrocarbon. The most efficient bacteria among these examined was Aeromonas hydrophila which biodegraded almost all tested hydrocarbon giving a treatment percentage of 98% within 30 days which was considered as the perfect period for degradation. Also, a small scale was designed to treat the spindle oil with the using of oxidation process and all the tested organic materials were biodegraded in a treatment percentage of 100% within retention time of 20 days.


Assuntos
Bactérias/metabolismo , Biodegradação Ambiental , Petróleo/microbiologia , Microbiologia do Solo , Poluentes do Solo/metabolismo , Aeromonas hydrophila/metabolismo , Bacillus subtilis/metabolismo , Bactérias/isolamento & purificação , Hidrocarbonetos/metabolismo , Petróleo/metabolismo , Poluição por Petróleo , Staphylococcus aureus/metabolismo , Viscosidade
8.
Ecotoxicol Environ Saf ; 201: 110798, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32526591

RESUMO

Despite constant progress in the understanding of the mechanisms related to the effects of biosurfactants in the bioremediation processes of oily residues, the possibility of antagonist effects on microbial growth and the production in situ of these compounds must be elucidated. The aims of this work were a) to evaluate the effects of the addition of a homemade biosurfactant of Bacillus methylotrophicus on the microbial count in soil in order to determine the possibility of inhibitory effects, and b) to accomplish biostimulation using media prepared with whey and bioaugmentation with B. methylotrophicus, analyzing the effects on the bioremediation of diesel oil and evidencing the in situ production of biosurfactants through effects on surface tension. The homemade bacterial biosurfactant did not present inhibitory effects acting as a biostimulant until 4000 mg biosurfactant/kg of soil. The biostimulation and bioaugmentation presented similar better results (p > 0.05) with the degradation of oil (~60%) than natural attenuation due to the low quantities of biostimulants added. For bioaugmentated and biostimulated soils, a decrease of surface tension between 30 and 60 days was observed, indicating the production of tensoactives in the soil, which was not observed in natural attenuation or a control treatment.


Assuntos
Bacillus/efeitos dos fármacos , Argila/química , Petróleo/análise , Poluentes do Solo/análise , Solo/química , Tensoativos/farmacologia , Bacillus/crescimento & desenvolvimento , Bacillus/metabolismo , Biodegradação Ambiental , Petróleo/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Tensoativos/química
9.
Chemosphere ; 257: 127109, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32497834

RESUMO

Used during an oil spill to minimise the formation of an oil slick, dispersants have negative biological effects on marine model organisms. However, no study has investigated the impacts of dispersants on adult sponge individuals. Here, we examine the effects of water accommodated oil fraction (WAF - oil in seawater), chemically enhanced WAF (CEWAF - oil and dispersant in seawater) and Benzo[A]Pyrene on sponge Halichondria panicea at physiological and molecular levels. Sponge clearance rate decreased sharply when exposed to WAF and CEWAF but the oil loading at which the clearance rate was reduced by 50% (ED50) was 39-fold lower in CEWAF than in WAF. Transcriptomic analysis revealed a homogenous molecular response with the greatest number of differentially expressed genes identified in CEWAF samples (1,461 genes). Specifically, genes involved in stress responses were up-regulated. This study presents evidence that the use of dispersants should be considered carefully in areas where sponges are present.


Assuntos
Recuperação e Remediação Ambiental , Poluição por Petróleo/análise , Petróleo/análise , Poríferos/fisiologia , Poluentes Químicos da Água/análise , Animais , Petróleo/metabolismo , Água do Mar , Poluentes Químicos da Água/metabolismo
10.
Proc Natl Acad Sci U S A ; 117(20): 11029-11037, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32354993

RESUMO

Marine cold seeps transmit fluids between the subseafloor and seafloor biospheres through upward migration of hydrocarbons that originate in deep sediment layers. It remains unclear how geofluids influence the composition of the seabed microbiome and if they transport deep subsurface life up to the surface. Here we analyzed 172 marine surficial sediments from the deep-water Eastern Gulf of Mexico to assess whether hydrocarbon fluid migration is a mechanism for upward microbial dispersal. While 132 of these sediments contained migrated liquid hydrocarbons, evidence of continuous advective transport of thermogenic alkane gases was observed in 11 sediments. Gas seeps harbored distinct microbial communities featuring bacteria and archaea that are well-known inhabitants of deep biosphere sediments. Specifically, 25 distinct sequence variants within the uncultivated bacterial phyla Atribacteria and Aminicenantes and the archaeal order Thermoprofundales occurred in significantly greater relative sequence abundance along with well-known seep-colonizing members of the bacterial genus Sulfurovum, in the gas-positive sediments. Metabolic predictions guided by metagenome-assembled genomes suggested these organisms are anaerobic heterotrophs capable of nonrespiratory breakdown of organic matter, likely enabling them to inhabit energy-limited deep subseafloor ecosystems. These results point to petroleum geofluids as a vector for the advection-assisted upward dispersal of deep biosphere microbes from subsurface to surface environments, shaping the microbiome of cold seep sediments and providing a general mechanism for the maintenance of microbial diversity in the deep sea.


Assuntos
Sedimentos Geológicos/microbiologia , Hidrocarbonetos/metabolismo , Microbiota/fisiologia , Água do Mar/microbiologia , Alcanos/metabolismo , Archaea/classificação , Archaea/metabolismo , Bactérias/classificação , Bactérias/metabolismo , Biodiversidade , Sedimentos Geológicos/química , Golfo do México , Metagenoma , Metagenômica , Petróleo/metabolismo , Filogenia , RNA Ribossômico 16S/genética , Água do Mar/química
11.
Chemosphere ; 256: 126998, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32470727

RESUMO

Efficient degradation of polycyclic aromatic hydrocarbons (PAHs) in a petroleum-contaminated soil was challenging which requires ample PAH-degrading flora and nutrients. In this study, we investigated the effects of 'natural attenuation', 'bioaugmentation', 'compost only (raw materials of compost included pig manure and rice husk mixed at a 1:2 proportion, supplemented with 2.5% charcoal)', and 'compost with bioaugmentation' treatments on degradation of polycyclic aromatic hydrocarbons (PAHs) and microbial community shifts during the remediation of petroleum-contaminated soil. After sixteen weeks of incubation, the removal efficiencies of PAHs were 0.52 ± 0.04%, 6.92 ± 0. 32%, 9.53 ± 0.29%, and 18.2 ± 0.64% in the four treatments, respectively. 'Compost with bioaugmentation' was the most effective for PAH removal among all the treatments. Illumina sequencing analysis suggested that both the 'compost only' and 'compost with bioaugmentation' treatments changed soil microbial community structures and enhanced microbial biodiversity. Some of the microorganisms affiliated with the compost including Azomonas, Luteimonas, Pseudosphingobacterium, and Parapedobacter were able to survive and become dominant in the contaminated soil. The 'bioaugmentation and 'natural attenuation' treatments had no significant effects on soil microbial community structure. Inoculation of the PAH degraders including Bacillus, Pseudomonas, and Acinetobacter directly into the contaminated soil led to lower biodiversity under natural conditions. This result suggested that compost addition increased the α-diversity of both the bacterial and fungal communities in petroleum-contaminated soil, leading to higher PAH degradation efficiency in petroleum-contaminated soil.


Assuntos
Petróleo/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Animais , Bactérias/metabolismo , Biodegradação Ambiental , Carvão Vegetal/metabolismo , Compostagem , Recuperação e Remediação Ambiental , Microbiota , Hidrocarbonetos Policíclicos Aromáticos/análise , Pseudomonas/metabolismo , Solo/química , Poluentes do Solo/análise , Suínos
12.
Chemosphere ; 252: 126349, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32443257

RESUMO

Biosurfactants have potential applications in the remediation of petroleum-contaminated sites. Several strategies can be used to reduce the production costs of these surfactants and make the process more environmentally friendly. In this study, we combined some of these strategies to produce the rhamnolipid-type biosurfactant, including the use of the genetically modified strain Pseudomonas aeruginosa-estA, an industrial coproduct as a carbon source, a simple and low-cost medium, and a simple downstream process. The process resulted in a high yield (17.6 g L-1), even using crude glycerin as the carbon source, with substrate in product conversion factor (YRML/s) of 0.444. The cell-free supernatant (CFS) was not toxic to Artemia salina and selected mammalian cell lineages, suggesting that it can be used directly in the environment without further purification steps. Qualitative analysis showed that CFS has excellent dispersion in the oil-displacement test, emulsifying (IE24 = 65.5%), and tensoactive properties. When salinity, temperature and pressure were set to seawater conditions, the values for interfacial tension between crude oil and water were below 1.0 mN m-1. Taken together, these results demonstrate that it is possible to obtain a nontoxic crude rhamnolipid product, with high productivity, to replace petroleum-based surfactants in oil spill cleanups and other environmental applications.


Assuntos
Biodegradação Ambiental , Glicolipídeos/metabolismo , Petróleo/metabolismo , Animais , Artemia , Carbono , Emulsões , Petróleo/análise , Poluição por Petróleo/análise , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/metabolismo , Tensão Superficial , Tensoativos/química , Temperatura
13.
Sci Rep ; 10(1): 8519, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32444666

RESUMO

A novel Bacillus licheniformis strain (DM-1) was isolated from a mature reservoir in Dagang oilfield of China. DM-1 showed unique properties to utilize petroleum hydrocarbons and agroindustrial by-product (molasses) for exopolysaccharide (EPS) production under oil recovery conditions. The DM-1 EPS was proven to be a proteoglycan with a molecular weight of 568 kDa. The EPS showed shear thinning properties and had high viscosities at dilute concentrations (<1%, w/v), high salinities, and elevated temperatures. Strain DM-1 could degrade long-chain n-alkanes up to C36. Viscosity reduction test have shown that the viscosity of the crude oil was reduced by 40% compared with that before DM-1 treatment. Sand pack flooding test results under simulated reservoir conditions have shown that the enhanced oil recovery efficiency was 19.2% after 7 days of in-situ bioaugmentation with B. licheniformis DM-1. The obtained results indicate that strain DM-1 is a promising candidate for in situ microbial enhanced oil recovery (MEOR).


Assuntos
Alcanos/metabolismo , Bacillus licheniformis/metabolismo , Biodegradação Ambiental , Hidrocarbonetos/metabolismo , Campos de Petróleo e Gás/microbiologia , Petróleo/metabolismo , Polissacarídeos Bacterianos/metabolismo , Bacillus licheniformis/isolamento & purificação
14.
Sci Rep ; 10(1): 8489, 2020 05 22.
Artigo em Inglês | MEDLINE | ID: mdl-32444776

RESUMO

The potentials of the invasive duckweed species, Lemna paucicostata to remove pollutants from aquatic environment was tested in a constructed wetlands as an ecological based system for the phytoremediation of petroleum hydrocarbons in crude oil-contaminated waters within 120 days. Total petroleum hydrocarbons in wetlands and tissues of duckweed were analyzed using gas chromatography with flame ionization detector following established methods while the experimental data were subjected to the first-order kinetic rate model to understand the remediation rate of duckweed in wetlands. L. paucicostata effected a significant (F = 253.405, P < 0.05) removal of hydrocarbons from wetlands reaching 97.91% after 120 days. Assessment on the transport and fate of hydrocarbons in duckweed indicated that L. paucicostata bioaccumulated less than 1% and significantly biodegraded 97.74% of hydrocarbons in wetlands at the end of the study. The experimental data reasonably fitted (r2 = 0.938) into the first-order kinetic rate model. From the result of the study, it is reasonable to infer that L. paucicostata is an effective aquatic macrophyte for the removal of petroleum hydrocarbons in moderately polluted waters.


Assuntos
Araceae/microbiologia , Biodegradação Ambiental , Hidrocarbonetos/análise , Modelos Estatísticos , Poluição por Petróleo/análise , Petróleo/metabolismo , Poluentes Químicos da Água/metabolismo , Ecossistema , Petróleo/análise , Petróleo/microbiologia , Poluentes Químicos da Água/análise , Áreas Alagadas
15.
Ecotoxicol Environ Saf ; 197: 110624, 2020 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-32302862

RESUMO

Crude oil and its derivatives are still the primary source of energy for humankind. However, during its transportation and treatment, spills of this resource can occur in aquatic environments. Nile tilapia is one of the most globally widespread fish species. This species is even found in brackish water due to its tolerance to salinity and pollution. In this study, the performance of brain cells (mitochondrial membrane potential [ΔΨm], calcium [Ca2+] and O2 and H2O2 levels) exposed to crude oil was assessed. In addition, fatty acid metabolism (cholesterol concentration and fatty acid synthase [FAS], acyl CoA-oxidase [AOX] and catalase [CAT] activities) in the brain, heart, liver and intestine of Nile tilapia exposed to the water-accommodated fraction (WAF) of 0.01, 0.1 or 1 g/L Maya crude oil (MCO) for 96 h were evaluated. After exposure, in brain cells, there were only increases in ROS and slight reductions in ΔΨm. Exposure to WAF of MCO induced and increased the levels of cholesterol and altered FAS and AOX activities in all examined tissues. The brain is the most susceptible organ to alterations in the activity of fatty acid metabolic enzymes and cholesterol levels relative to the heart, liver and intestine. The correlation between inhibition of the activity of CAT and AOX suggests a possible reduction in the proliferation and size of peroxisomes. Most biomarkers were significantly altered in the brains of Nile tilapia exposed to the WAF containing 1 g/L MCO in comparison to the control.


Assuntos
Encéfalo/efeitos dos fármacos , Ciclídeos/metabolismo , Ácidos Graxos/metabolismo , Metabolismo dos Lipídeos/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Petróleo/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Encéfalo/metabolismo , Ácido Graxo Sintases/metabolismo , Peróxido de Hidrogênio/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Mitocôndrias/metabolismo , Petróleo/metabolismo , Poluentes Químicos da Água/metabolismo
16.
Ecotoxicol Environ Saf ; 194: 110409, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32155481

RESUMO

Phytoremediation is a promising "green technique" used to purify contaminated soils. The performed phytoremediation experiments assisted by the fertilization process involving pots of F.arundinacea grown on soils with diverse concentrations and types of contaminations produced the following decreased percentages after 6 months: Pb (25.4-34.1%), Ni (18.7-23.8%), Cd (26.3-46.7%), TPH (49.4-60.1%). Primarily, TPH biodegradation was occurring as a result of basic bioremediation stimulated by adding optimal volumes of biogenic substances and corrections in the soil reaction, while phytoremediation improved this process by 17.4 - 23.1%. The highest drop in a range of 45.6 - 55.5% was recorded for the group of C12-C18 hydrocarbons, with the lowest one for C25-C36, amounting to 9.1-17.4%. Translocation factor values were: TF<1 and ranged, respectively, for: Pb (0.46-0.53), Ni (0.29-0.33), and Cd (0.21-0.25), which indicate that heavy metals absorbed by Festuca arundinacea they mainly accumulated in the root of the tissue in descending order: Cd

Assuntos
Festuca/metabolismo , Metais Pesados/análise , Petróleo/análise , Poluentes do Solo/análise , Solo/química , Biodegradação Ambiental , Cádmio/análise , Cádmio/metabolismo , Festuca/efeitos dos fármacos , Germinação/efeitos dos fármacos , Chumbo/análise , Chumbo/metabolismo , Lepidium sativum/metabolismo , Metais Pesados/metabolismo , Níquel/análise , Níquel/metabolismo , Petróleo/metabolismo , Poluentes do Solo/metabolismo
17.
Chemosphere ; 250: 126303, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32120151

RESUMO

This study demonstrates the feasibility of using Exiguobacterium sp. AO-11 to remediate oil-contaminated environments. Bioaugmentation using AO-11 showed the best removal percentage, 75%, of 4% (w/w) crude oil in sediment microcosms in 100 days. In terms of the bacterial community structure during crude oil degradation, the addition of AO-11 did not change the indigenous bacterial community, while the addition of urea fertilizer induced structural shift of indigenous bacterial community. Exiguobacterium sp. AO-11 was developed as a bioremediation product, and a liquid formulation of AO-11 was developed. Coconut milk residue and soybean oil mill sludge were used for bacterial cultivation to reduce the production cost, and they could enhance bacterial cell growth. The liquid formulation of AO-11 prepared in phosphate buffer could be stored at 4 °C for at least 2 months, and it maintained efficacy in the treatment of crude oil-contaminated seawater. Overall, bioaugmentation with strain AO-11 could be an effective solution for the bioremediation of crude oil-contaminated environments.


Assuntos
Biodegradação Ambiental , Petróleo/metabolismo , Bacillaceae/metabolismo , Bactérias/metabolismo , Fertilizantes , Poluição por Petróleo , Água do Mar/química , Microbiologia do Solo
18.
Sci Rep ; 10(1): 4094, 2020 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-32139706

RESUMO

Most components of petroleum oily sludge (POS) are toxic, mutagenic and cancer-causing. Often bioremediation using microorganisms is hindered by the toxicity of POS. Under this circumstance, phytoremediation is the main option as it can overcome the toxicity of POS. Cajanus cajan a legume plant, was evaluated as a phyto-remediating agent for petroleum oily sludge-spiked soil. Culture dependent and independent methods were used to determine the rhizosphere microorganisms' composition. Degradation rates were estimated gravimetrically. The population of total heterotrophic bacteria (THRB) was significantly higher in the uncontaminated soil compared to the contaminated rhizosphere soil with C. cajan, but the population of hydrocarbon-utilizing bacteria (HUB) was higher in the contaminated rhizosphere soil. The results show that for 1 to 3% oily sludge concentrations, an increase in microbial counts for all treatments from day 0 to 90 d was observed with the contaminated rhizosphere CR showing the highest significant increase (p < 0.05) in microbial counts compared to other treatments. The metagenomic study focused on the POS of 3% (w/w) and based on the calculated bacterial community abundance indices showed an increase in the values for Ace, Cho, Shannon (Shannon-Weaver) and the Simpson's (measured as InvSimpson) indices in CR3 compared to CN3. Both the Simpson's and the Shannon values for CR3 were higher than CN3 indicating an increase in diversity upon the introduction of C. cajan into the contaminated soil. The PCoA plot revealed community-level differences between the contaminated non-rhizosphere control and contaminated rhizosphere microbiota. The PCoA differentiated the two treatments based on the presence or absence of plant. The composition and taxonomic analysis of microbiota-amplified sequences were categorized into eight phyla for the contaminated non-rhizosphere and ten phyla for the contaminated rhizosphere. The overall bacterial composition of the two treatments varied, as the distribution shows a similar variation between the two treatments in the phylum distribution. The percentage removal of total petroleum hydrocarbon (TPH) after 90 days of treatments with 1, 2, 3, 4, and 5% (w/w) of POS were 92, 90, 89, 68.3 and 47.3%, respectively, indicating removal inhibition at higher POS concentrations. As the search for more eco-friendly and sustainable remediating green plant continues, C. cajan shows great potential in reclaiming POS contaminated soil. Our findings will provide solutions to POS polluted soils and subsequent re-vegetation.


Assuntos
Bactérias/metabolismo , Biodegradação Ambiental , Cajanus/metabolismo , Petróleo/metabolismo , Esgotos/análise , Poluentes do Solo/metabolismo , Solo/química , Bactérias/classificação , Bactérias/genética , Biodiversidade , Cajanus/crescimento & desenvolvimento , Cajanus/microbiologia , Monitoramento Ambiental , Microbiota , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Rizosfera , Poluentes do Solo/isolamento & purificação
19.
Artigo em Inglês | MEDLINE | ID: mdl-32131529

RESUMO

Due to the increasing pollution by petroleum hydrocarbons (PHs), it is an important task to develop eco-friendly and highly efficient methods for remediating petroleum-contaminated soils. In this study, bioremediation technology was applied to remediate PHs contaminated soils, and the bacterial community structure and physicochemical characteristics of the soil treated using different bioremediation regimens were analyzed. Compared with the control condition (S0), the PHs removal efficiency of biostimulation (S2) and bioaugmentation (S3) was increased significantly. Combined biostimulation with bioaugmentation (S4) had the highest PHs removal efficiency, up to 60.14 ± 4.12%. Among all the selected remediation strategies (S1-S4, S1: soil moisture content: 25-30%), the bacterial alpha-diversity was higher than in S0. The genera Acinetobacter, Escherichia-Shigella, Bacteroides, Microbacterium, and Parabacteroides were found to greatly contribute to PHs' degradation. In the group S4, the PH-degraders and soil enzyme activity were higher than in the other remediation regimens, and these indices gradually decreased in the mid-to-later periods of all remediation tests. Additionally, the abundance of alkB and nah genes was increased by improving the environmental condition of the microorganism communities. Redundancy analysis (RDA) revealed that the total nitrogen (TN) and total phosphorus (TP) had a positive correlation with total PHs degradation. This study offers insights into the microbial community response to environmental factors during bioremediation, which shows a promoting effect in enhancing the efficiency of PHs remediation.


Assuntos
Biodegradação Ambiental , Recuperação e Remediação Ambiental , Petróleo , Microbiologia do Solo , Poluentes do Solo , Bactérias/metabolismo , Recuperação e Remediação Ambiental/métodos , Hidrocarbonetos/metabolismo , Petróleo/metabolismo , Solo/química
20.
Ecotoxicol Environ Saf ; 192: 110250, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32028154

RESUMO

A bacterial strain designated Lysinibacillus fusiformis 15-4 was isolated from oil-free soil on the Qinghai-Tibet Plateau, which can grow well utilizing petroleum hydrocarbons as a carbon source at a lower temperature. To deeply characterize the molecular adaptations and metabolic processes of this strain when grown in a petroleum-containing environment, transcriptome analysis was performed. A total of 4664 genes and the expression of 3969 genes were observed in strain 15-4. When the strain was grown in petroleum-containing medium, 2192 genes were significantly regulated, of which 1312 (60%) were upregulated and 880 (40%) were downregulated. This strain degraded and adapted to petroleum via modulation of diverse molecular processes, including improvements in transporter activity, oxidoreductase/dehydrogenase activity, two-component system/signal transduction, transcriptional regulation, fatty acid catabolism, amino acid metabolism, and environmental stress responses. Many strain-specific genes were involved in the oxidation of hydrocarbon compounds, such as several luciferase family alkane monooxygenase genes, flavin-utilizing monooxygenase family genes, and flavoprotein-like family alkanesulfonate monooxygenase genes. Several cold shock protein genes were also induced suggesting adaptation to cold environments and the potential for petroleum degradation at low temperatures. The results obtained in this study may broaden our understanding of molecular adaptation of bacteria to hydrocarbon-containing environments and may provide valuable data for further study of L. fusiformis.


Assuntos
Bacillaceae/genética , Bacillaceae/metabolismo , Petróleo/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Adaptação Fisiológica , Bacillaceae/isolamento & purificação , Biodegradação Ambiental , Proteínas e Peptídeos de Choque Frio/biossíntese , Proteínas e Peptídeos de Choque Frio/genética , Temperatura Baixa , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Hidrocarbonetos/metabolismo , Oxigenases de Função Mista/biossíntese , Oxigenases de Função Mista/genética , Microbiologia do Solo , Tibet
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