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The Journal of Physical Chemistry. A Aug 2022In this work, the conformer-rotamer ensemble sampling tool (CREST), with the underlying semiempirical GFN2-xtb method, was used for automated geometry exploration of the...
In this work, the conformer-rotamer ensemble sampling tool (CREST), with the underlying semiempirical GFN2-xtb method, was used for automated geometry exploration of the homodimers of pyrene, pyrene-4,5-dione, and pyrene-4,5,9,10-tetraone, along with the heterodimer of pyrene and pyrene-4,5,9,10-tetraone. Geometries and energies of the dimers were further refined at the ωB97X-D4/def2-TZVP level of theory, both in the gas phase and in toluene solution. Computations in solution were handled using the CPCM (conductor-like polarizible continuum model) and SMD (solvation model based on density) models. Two previously unidentified pyrene-homodimer conformations were identified, and the effects of oxidation on the geometries and energies of dimerization were explored; in general, oxidation leads to stronger intermolecular interactions and decreased solubility in toluene. For selected dimers, DLPNO-CCSD(T)/cc-pVTZ/SMD(Toluene) energies were determined at the DFT geometries and illustrated the accuracy of the ωB97X-D4 approach, with an MAD of 1.47 kJ/mol.
Topics: Dimerization; Oxides; Pyrenes; Quantum Theory; Toluene
PubMed: 35882012
DOI: 10.1021/acs.jpca.2c02666 -
The Science of the Total Environment Jul 2022The toxicity of pyrene (Pyr) and its chlorinated species have not be comprehensively and clearly elucidated. In this study, an integrated approach of metabolomics and...
The toxicity of pyrene (Pyr) and its chlorinated species have not be comprehensively and clearly elucidated. In this study, an integrated approach of metabolomics and transcriptomics were applied to evaluate the hepatotoxicity of Pyr and 1-chloropyrene (1-Cl-Pyr) at human exposure level, using human L02 hepatocytes. After 24 h exposure to Pyr and 1-Cl-Pyr at 5-500 nM, cell viability was not significantly changed. Transcriptomics results showed that exposure to Pyr and 1-Cl-Pyr at 5 and 50 nM obviously altered the gene expression profiles, but did not significantly induce the expression of genes strongly related to the activation of aryl hydrocarbon receptor (AhR), such as CYP1A1, CYP1B1, AHR, ARNT. Pyr and 1-Cl-Pyr both induced a notable metabolic perturbation to L02 cells. Glycerophospholipid metabolism was found to be the most significantly perturbed pathway after exposure to Pyr and 1-Cl-Pyr, indicating their potential damage to the cell membrane. The other significantly perturbed pathways were identified to be oxidative phosphorylation (OXPHOS), glycolysis, and fatty acid β oxidation, all of which are related to energy production. Exposure to Pyr at 5 and 50 nM induced the up-regulation of fatty acid β oxidation and OXPHOS. The similar result was observed after exposure to 5 nM 1-Cl-Pyr. In contrast, exposure to 50 nM 1-Cl-Pyr induced the down-regulation of OXPHOS by inhibiting the activity of complex I. The obtained results suggested that the modes of action of Pyr and 1-Cl-Pyr on energy production remarkably varied not only with molecular structure change but also with exposure concentration.
Topics: Chemical and Drug Induced Liver Injury; Cytochrome P-450 CYP1A1; Fatty Acids; Humans; Metabolomics; Polycyclic Aromatic Hydrocarbons; Pyrenes; Receptors, Aryl Hydrocarbon; Transcriptome
PubMed: 35307418
DOI: 10.1016/j.scitotenv.2022.154637 -
Applied Microbiology and Biotechnology Dec 2022The colonization of degrading endophytic bacteria is an effective means to reduce the residues of polycyclic aromatic hydrocarbons (PAHs) in crops. Dicarboxylic acids,...
The colonization of degrading endophytic bacteria is an effective means to reduce the residues of polycyclic aromatic hydrocarbons (PAHs) in crops. Dicarboxylic acids, as the main active components in crops, can affect the physiological activities of endophytic bacteria and alter the biodegradation process of PAHs in crops. In this study, malonic acid and succinic acid were selected as the representatives to investigate the contribution of dicarboxylic acids to pyrene biodegradation by endophytic Enterobacter sp. PRd5 in vitro. The results showed that dicarboxylic acids improved the biodegradation of pyrene and altered the expression of the functional gene of strain PRd5. Malonic acid and succinic acid reduced the half-life of pyrene by 20.0% and 27.8%, respectively. The degrading enzyme activities were significantly stimulated by dicarboxylic acids. There were 386 genes up-regulated and 430 genes down-regulated in strain PRd5 with malonic acid, while 293 genes up-regulated and 340 genes down-regulated with succinic acid. Those up-regulated genes were distributed in the functional classification of signal transduction, membrane transport, energy metabolism, carbohydrate metabolism, and amino acid metabolism. Malonic acid mainly enhanced the central carbon metabolism, cell proliferation, and cell activity. Succinic acid mainly improved the expression of degrading gene. Overall, the findings of this study provide new insights into the regulation and control of PAH stress by crops. KEY POINTS: • Dicarboxylic acids improved the biodegradation of pyrene by Enterobacter sp. PRd5. • The degrading enzyme activities were stimulated by dicarboxylic acids. • There are different facilitation mechanisms between malonic acid and succinic acid.
Topics: Dicarboxylic Acids; Enterobacter; Transcriptome; Pyrenes; Biodegradation, Environmental; Polycyclic Aromatic Hydrocarbons; Succinates
PubMed: 36227340
DOI: 10.1007/s00253-022-12217-1 -
Spectrochimica Acta. Part A, Molecular... Feb 2024The detection of residual tetracycline antibiotics (TCs) in the aquatic environment is important because of the irreversible damage of TCs to the ecosystem and human...
The detection of residual tetracycline antibiotics (TCs) in the aquatic environment is important because of the irreversible damage of TCs to the ecosystem and human health. Considering the photostability, sensitivity, and accuracy of the detection systems, mesoporous SBA-15 silica material was an ideal support matrix for improving photostability because it can protect the optical properties of fluorescent signals. To achieve ratiometric detection (with sensitivity and accuracy), pyrene and Eu as two fluorescent signals were implemented into SBA-15, and an organic-inorganic hybrid fluorescent nanoprobe Py/EDTA-SBA-15@Eu was constructed. In the presence of TCs, the red emission of Eu in the nanoprobe was sensitized, and the fluorescence resonance energy transfer occurred from pyrene to Eu, resulting in the increased emission of Eu at 617 nm and the decreased emission of pyrene at 384 nm. By monitoring the fluorescent intensity changes at 617 and 384 nm (F/F), the nanoprobe achieved the ratiometric detection of oxytetracycline (OTC) and tetracycline (TC) in the range of 0.20-80 and 0.40-80 μM, respectively, with detection limits of 0.18 nM for OTC and 5.83 nM for TC. In addition, the practical application of the nanoprobe was validated in tap water and honey samples.
Topics: Humans; Fluorescent Dyes; Ecosystem; Europium; Anti-Bacterial Agents; Tetracycline; Silicon Dioxide; Oxytetracycline; Pyrenes; Spectrometry, Fluorescence
PubMed: 37976571
DOI: 10.1016/j.saa.2023.123638 -
Ecotoxicology and Environmental Safety Dec 2021Persistent and ubiquitous organic pollutants, such as the polycyclic aromatic hydrocarbon benzo[⍺]pyrene (BaP), represent a major threat to aquatic organisms and human...
Persistent and ubiquitous organic pollutants, such as the polycyclic aromatic hydrocarbon benzo[⍺]pyrene (BaP), represent a major threat to aquatic organisms and human health. Beside some well-documented adverse effects on the development and reproduction of aquatic organisms, BaP was recently shown to affect fish bone formation and skeletal development through mechanisms that remain poorly understood. In this work, zebrafish bone-related in vivo assays were used to evaluate the osteotoxic effects of BaP during bone development and regeneration. Acute exposure of zebrafish larvae to BaP from 3 to 6 days post-fertilization (dpf) induced a dose-dependent reduction of the opercular bone size and a depletion of osteocalcin-positive cells, indicating an effect on osteoblast maturation. Chronic exposure of zebrafish larvae to BaP from 3 to 30 dpf affected the development of the axial skeleton and increased the incidence and severity of skeletal deformities. In young adults, BaP affected the mineralization of newly formed fin rays and scales, and impaired fin ray patterning and scale shape, through mechanisms that involve an imbalanced bone remodeling. Gene expression analyses indicated that BaP induced the activation of xenobiotic and metabolic pathways, while negatively impacting extracellular matrix formation and organization. Interestingly, BaP exposure positively regulated inflammation markers in larvae and increased the recruitment of neutrophils. A direct interaction between neutrophils and bone extracellular matrix or bone forming cells was observed in vivo, suggesting a role for neutrophils in the mechanisms underlying BaP osteotoxicity. Our work provides novel data on the cellular and molecular players involved in BaP osteotoxicity and brings new insights into a possible role for neutrophils in inflammatory bone reduction.
Topics: Animals; Benzo(a)pyrene; Humans; Larva; Polycyclic Aromatic Hydrocarbons; Pyrenes; Zebrafish
PubMed: 34607190
DOI: 10.1016/j.ecoenv.2021.112838 -
Functional Plant Biology : FPB Mar 2023Polycyclic aromatic hydrocarbons are persistent organic pollutants causing serious environmental problems, being toxic to plants and difficult to remediate. Pyrene is...
Polycyclic aromatic hydrocarbons are persistent organic pollutants causing serious environmental problems, being toxic to plants and difficult to remediate. Pyrene is one such extremely dangerous compound that is toxic for the environment. This study suggests the use of Bacillus subtilis (National Collection of Industrial Microorganisms [NCIM] 5594) to overcome inhibitory effects of pyrene on soybean photosynthesis. The toxicity of pyrene to soybean was evident from a significant decrease in seed germination parameters, photosynthetic performance and biomass during growth of soybean in pyrene contaminated soil. Efficiency of performance index, light absorption, trapping and electron transport were reduced in plants grown in pyrene contaminated soil while significant recovery in these parameters was observed in plants grown in pyrene+B. subtilis treated soil. Activity levels of dehydrogenase and lipase enzymes significantly recovered in pyrene+B. subtilis treated soil. After extraction of pyrene from soil and soybean plant, concentration of pyrene was lowered in pyrene+B. subtilis treated soil and plants. These findings suggest efficient degradation of pyrene by B. subtilis . About 70% degradation of pyrene was achieved in soil using B. subtilis ; thus it is a useful strain for crop improvement in pyrene polluted soil.
Topics: Bacillus subtilis; Glycine max; Soil Pollutants; Pyrenes; Photosynthesis; Soil
PubMed: 36372780
DOI: 10.1071/FP22172 -
The Science of the Total Environment Mar 2021Partial transformation of pollutants and mobilization of the produced metabolites may contribute significantly to the risks resulting from biological treatment of soils...
Partial transformation of pollutants and mobilization of the produced metabolites may contribute significantly to the risks resulting from biological treatment of soils polluted by hydrophobic chemicals such as polycyclic aromatic hydrocarbons (PAHs). Pyrene, a four-ringed PAH, was selected here as a model pollutant to study the effects of sunflower plants on the bacterial accessibility and cometabolism of this pollutant when located at a spatially distant source within soil. We compared the transformation of passively dosed C-labeled pyrene in soil slurries and planted pots that were inoculated with the bacterium Pseudomonas putida G7. This bacterium combines flagellar cell motility with the ability to cometabolically transform pyrene. Cometabolism of this PAH occurred immediately in the inoculated and shaken soil slurries, where the bacteria had full access to the passive dosing devices (silicone O-rings). Root exudates did not enhance the survival of P. putida G7 cells in soil slurries, but doubled their transport in column tests. In greenhouse-incubated soil pots with the same pyrene sources instead located centimeters from the soil surface, the inoculated bacteria transformed C-labeled pyrene only when the pots were planted with sunflowers. Bacterial inoculation caused mobilization of C-labeled pyrene metabolites into the leachates of the planted pots at concentrations of approximately 1 mg L, ten times greater than the water solubility of the parent compound. This mobilization resulted in a doubled specific root uptake rate of C-labeled pyrene equivalents and a significantly decreased root-to-fruit transfer rate. Our results show that the plants facilitated bacterial access to the distant pollutant source, possibly by increasing bacterial dispersal in the soil; this increased bacterial access was associated with cometabolism, which contributed to the risks of biodegradation.
Topics: Bacteria; Biodegradation, Environmental; Polycyclic Aromatic Hydrocarbons; Pyrenes; Soil; Soil Microbiology; Soil Pollutants
PubMed: 33243519
DOI: 10.1016/j.scitotenv.2020.143408 -
Environmental Technology Nov 2022Polycyclic aromatic hydrocarbons (PAHs) are key organic pollutants in the environment that pose threats to the ecosystem and human health. The degradation of high...
Polycyclic aromatic hydrocarbons (PAHs) are key organic pollutants in the environment that pose threats to the ecosystem and human health. The degradation of high molecular weight (HMW) PAHs by enriched bacterial consortia has been previously studied, while the involved metabolisms and microbial communities are still unclear and warrant further investigations. In this study, five bacterial consortia capable of utilizing different PAHs (naphthalene, anthracene, and pyrene) as the sole carbon and energy sources were enriched from PAH-contaminated soil samples. Among the five consortia, consortium TC exhibited the highest pyrene degradation efficiency (91%) after 19 d of incubation. The degradation efficiency was further enhanced up to 99% by supplementing yeast extract. Besides, consortium TC showed tolerances to high concentrations of pyrene (up to 1000 mg/L) and different heavy metal stresses (including Zn, Cd, and Pb). The dominant genus in consortium TC, GS, and PL showing relatively higher degradation efficiency for anthracene and pyrene was , whereas consortium PG and GD were predominated by genus and class Enterobacteriaceae, respectively. Consortium TC, as a highly efficient HMW PAH-degrading consortium, could be applied for synergistic biodegradation of HMW PAHs and in situ bioremediation of the sites contaminated with both PAHs and heavy metals.
Topics: Humans; Biodegradation, Environmental; Polycyclic Aromatic Hydrocarbons; Ecosystem; Molecular Weight; Soil Pollutants; Bacteria; Pyrenes; Metals, Heavy; Anthracenes; Soil Microbiology
PubMed: 34148513
DOI: 10.1080/09593330.2021.1946163 -
Environmental Science and Pollution... Jan 2023Micro- and nano-plastics (MNPs) in terrestrial ecosystems are attracting increasing attentions. However, the studies of MNPs on the accumulation and migration of organic...
Micro- and nano-plastics (MNPs) in terrestrial ecosystems are attracting increasing attentions. However, the studies of MNPs on the accumulation and migration of organic contaminants in edible plants are relatively scarce. Here, we investigated the impacts and mechanisms of MNPs of different concentrations and sizes on the uptake and toxicity of pyrene in water spinach. The results showed that MNPs had a promotion effect on the uptake of pyrene in various parts of water spinach, leading to the continuous accumulation of pyrene. The promotion effect of high concentration microplastics (MPs, 10 μm) is stronger than that of nanoplastics (NPs, 100 nm). The co-exposure of MNPs and pyrene increased the contents of malondialdehyde (MDA) in water spinach and aggravated the damage of lipid peroxidation. The co-exposure of MNPs and pyrene induced the increase of photosynthetic pigment contents and enhanced chloroplast activity. In addition, the co-exposure stimulated the overexpression of psbA and rbcL genes related to photosynthetic pigments, resulting in genotoxicity of water spinach. This study emphasized that the co-exposure of MNPs and pyrene caused harmful effects and high concentration of MPs caused greater toxicity to water spinach than NPs.
Topics: Microplastics; Ipomoea; Ecosystem; Plastics; Pyrenes; Water Pollutants, Chemical
PubMed: 35907066
DOI: 10.1007/s11356-022-22156-z -
Journal of Hazardous Materials Feb 2022Microbial carriers may co-transport polycyclic aromatic hydrocarbons (PAHs), but lack substantial experimental evidence. Cable bacteria use gliding or twitching motility...
Microbial carriers may co-transport polycyclic aromatic hydrocarbons (PAHs), but lack substantial experimental evidence. Cable bacteria use gliding or twitching motility to access sulfide; hence, they could be important microbial carriers in co-transporting PAHs from the sediment-water interface into suboxic zones. In this study, the effect of cable bacteria on pyrene migration was investigated by connecting or blocking the paths of cable bacteria to the suboxic zones. The results showed that downward migration of pyrene in the connecting groups were significantly higher (17.3-49.2%, p < 0.01) than those in the control groups. Meanwhile, significant downward migration of microbial communities in the connecting groups were also observed, including abundant filamentous-motile microorganisms, especially cable bacteria. The adsorption of surrounding particles by cable bacteria were morphologically evidenced. The biomechanical model based on the Peclet number indicated that filamentous-motile microorganisms demonstrated stronger adsorption ability for pyrene than other microorganisms. Supposedly, the downward migration of microbial communities, especially cable bacteria, significantly enhanced pyrene migration, thus influencing the distribution and ecological risk of pyrene in sediments. This study provides new insights into the important roles of motile microorganisms in the migration of PAHs in sediments, shedding lights on guidance for ecological risk assessment of PAHs.
Topics: Bacteria; Geologic Sediments; Polycyclic Aromatic Hydrocarbons; Pyrenes; Sulfides
PubMed: 34597936
DOI: 10.1016/j.jhazmat.2021.127188