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1.
Arch Microbiol ; 204(5): 248, 2022 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-35397012

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are the hazardous xenobiotic agents of oil production. One of the methods to eliminate hazardous compounds is bioremediation, which is the most efficient and cost-effective method to eliminate the harmful byproducts of crude petroleum processing. In this study, five pure bacterial isolates were isolated from petroleum-contaminated soil, four of which showed a robust growth on the PAH pyrene, as a sole carbon source. Various methods viz mass spectroscopy, biochemical assays, and 16S RNA sequencing employed to identify the isolates ascertained the consistent identification of Klebsiella oxytoca by all three methods. Scanning electron microscopy and Gram staining further demonstrated the characterization of the K. oxytoca. High-performance liquid chromatography of the culture supernatant of K. oxytoca grown in pyrene containing media showed that the cells started utilizing pyrene from the 6th day onwards and by the 12th day of growth, 70% of the pyrene was completely degraded. A genome search for the genes predicted to be involved in pyrene degradation using Kyoto Encyclopedia of Genes and Genomes (KEGG) confirmed their presence in the genome of K. oxytoca. These results suggest that K. oxytoca would be a suitable candidate for removing soil aromatic hydrocarbons.


Assuntos
Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Bactérias/genética , Biodegradação Ambiental , Klebsiella oxytoca/genética , Klebsiella oxytoca/metabolismo , Petróleo/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Pirenos , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Solo , Microbiologia do Solo , Poluentes do Solo/metabolismo
2.
J Phys Chem Lett ; 13(16): 3529-3533, 2022 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-35420036

RESUMO

The influence of incremental hydration (≤4) on the electronic resonances of the pyrene anion is studied using two-dimensional photoelectron spectroscopy. The photoexcitation energies of the resonances do not change; therefore, from the anion's perspective, the resonances remain the same, but from the neutral's perspective of the electron-molecule reaction, the resonances decrease in energy by the binding energy of the water molecules. The autodetachment of the resonances shows that hydration has very little effect, showing that even the dynamics of most of the resonances are not impacted by hydration. Two specific resonances do show changes that are explained by the closing of specific autodetachment channels. The lowest-energy resonance leads to efficient electron capture as observed through thermionic emission and evaporation of water molecules (dissociative electron attachment). The implications of low-energy electron capture in dense molecular interstellar clouds are discussed.


Assuntos
Elétrons , Água , Ânions/química , Espectroscopia Fotoeletrônica , Pirenos , Água/química
3.
Anal Chem ; 94(17): 6621-6627, 2022 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-35441505

RESUMO

In accurately diagnosing Alzheimer's disease (AD) and distinguishing AD from other dementia, the concentration ratio of amyloid-beta 42 (Aß42) to Aß40 is more reliable than the concentration of Aß42 alone. For the multiplex PEC assay, generating an independent photocurrent of multiple targets on a single interface is a great challenge. Herein, an i-motif-based switchable sensing approach is proposed to construct a pH-regulated multiplex PEC immunosensor for Aß42 and Aß40 by using Bi-TBAPy as an efficient photoactive cathode material. An independent photocurrent signal of Aß42 and Aß40 is produced through the regulation of the electron-transfer tunneling distance by a pH-dependent configuration transition of the i-motif DNA. In a 96-well plate, immunological recognition of Aß42 (or Aß40) coupled with an enzymatic catalytic reaction produces an acidic (or alkaline) lysis solution, which triggers the formation and unravelment of the i-motif structure. The above configuration transition regulates the distance between Au NPs labeled SH-DNA and Bi-TBAPy, leading to PEC signal switching. Smart integration of the pH-responsive switchable DNA probe with a high-efficiency photocathode enables the precise monitoring of Aß42 and Aß40 at a single interface in a wide detection range (10 fg/mL ∼ 1 µg/mL and 1 pg/mL ∼ 1 µg/mL) with detection limit of 4.5 fg/mL and 0.52 pg/mL, respectively. The proposed i-motif-based switchable sensing strategy paves a new avenue for a multiplex PEC assay on a single interface, showing great prospects in bioanalysis and early disease diagnosis.


Assuntos
Doença de Alzheimer , Técnicas Biossensoriais , Doença de Alzheimer/diagnóstico , Peptídeos beta-Amiloides , Humanos , Concentração de Íons de Hidrogênio , Imunoensaio , Pirenos
4.
Sensors (Basel) ; 22(7)2022 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-35408378

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous pollutants that are typically released into the environment during the incomplete combustion of fossil fuels. Due to their relevant carcinogenicity, mutagenicity, and teratogenicity, it is urgent to develop sensitive and cost-effective strategies for monitoring them, especially in aqueous environments. Surface-enhanced Raman spectroscopy (SERS) can potentially be used as a reliable approach for this purpose, as it constitutes a valid alternative to traditional techniques, such as liquid and gas chromatography. Nevertheless, the development of an SERS-based platform for detection PAHs has so far been hindered by the poor adsorption of PAHs onto silver- and gold-based SERS-active substrates. To overcome this limitation, several research efforts have been directed towards the development of functionalized SERS substrates for the improvement of PAH adsorption. However, these strategies suffer from the interference that functionalizing molecules can produce in SERS detection. Herein, we demonstrate the feasibility of label-free detection of pyrene by using a highly porous 3D-SERS substrate produced by an inductively coupled plasma (ICP). Thanks to the coral-like nanopattern exhibited by our substrate, clear signals ascribable to pyrene molecules can be observed with a limit of detection of 23 nM. The observed performance can be attributed to the nanoporous character of our substrate, which combines a high density of hotspots and a certain capability of trapping molecules and favoring their adhesion to the Ag nanopattern. The obtained results demonstrate the potential of our substrates as a large-area, label-free SERS-based platform for chemical sensing and environmental control applications.


Assuntos
Nanopartículas Metálicas , Hidrocarbonetos Policíclicos Aromáticos , Estudos de Viabilidade , Nanopartículas Metálicas/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Porosidade , Pirenos , Prata/química , Análise Espectral Raman/métodos , Água
5.
Artigo em Inglês | MEDLINE | ID: mdl-35483786

RESUMO

The genotoxicity of pyrene-polyethylene glycol-modified multi-walled carbon nanotubes (MWCNT-PyPEG), engineered as a nanoplatform for bioapplication, was evaluated. Toxicity was assessed in hamster lung fibroblast cells (V79-4). MTT and Cell Titer Blue methods were used to evaluate cell viability. Genotoxicity was measured by the comet assay and the cytokinesis-block micronucleus cytome (CBMN-Cyt) assay, and fluorescence in situ hybridization (FISH) was used to test induction of structural chromosome aberrations (clastogenic activity) and/or numerical chromosome changes (aneuploidogenic activity). Exogenous metabolic activation enzymes were used in the CBMN-Cyt and FISH tests. Only with metabolic activation, the hybrids caused chromosomal damage, by both clastogenic and aneugenic processes.


Assuntos
Nanotubos de Carbono , Animais , Cricetinae , Fibroblastos , Hibridização in Situ Fluorescente/métodos , Mutagênicos/toxicidade , Nanotubos de Carbono/toxicidade , Polietilenoglicóis/toxicidade , Pirenos/toxicidade
6.
Anal Chim Acta ; 1206: 339648, 2022 May 08.
Artigo em Inglês | MEDLINE | ID: mdl-35473864

RESUMO

In this work, a pyrene-based porous organic polymer (Py-POP) with strong electrochemiluminescence (ECL) emission was synthesized and used to fabricate an ECL sensor for the extra-sensitive detection of microRNA-155. The ECL intensity of the Py-POP prepared by tetra(p-aminophenyl)methane (TAPM) and 1,3,6,8-tetrakis(4-formylphenyl)pyrene (TFPPy) was about 3.1 times that of TFPPy aggregates, which was primarily ascribed to the elimination of the effect of aggregation-caused quenching (ACQ) by increasing the distance between ACQ luminophores (pyrene cores) in Py-POP. Meanwhile, the strong covalent connections between 1,3,6,8-tetraphenylpyrene (TPPy) and tetraphenylmethane (TPM) units in the rigid framework of Py-POP could partly block the intramolecular motion of TPPy and TPM, which reduced the non-radiative decay and thus further improved the ECL emission. Furthermore, the hydrophobic porous structure of Py-POP was beneficial to the enrichment of lipophilic tripropylamine (TPrA) coreactants in pores of Py-POP, which greatly shortened the electron migration distance between TPrA coreactants and pyrene luminophores on the pore walls of Py-POP, thereby also enhancing the ECL intensity. By using the Py-POP as a new ECL tag and with the help of the strand displacement processes and target recycling, the fabricated ECL biosensor had a sensitive response for microRNA-155 from 1 fM to 1 nM and a detection limit of 0.326 fM. Overall, this work provided a new and feasible strategy to surmount the ACQ effect for enhancing ECL emission, which not only paved a new way to exploit high-performance ECL materials for fabricating extra-sensitive sensors but also broadened the application of POPs in bioanalysis and ECL fields.


Assuntos
MicroRNAs , Polímeros , Técnicas Eletroquímicas , Medições Luminescentes , MicroRNAs/análise , Polímeros/química , Porosidade , Pirenos
7.
Molecules ; 27(6)2022 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-35335388

RESUMO

In recent years, conjugated microporous polymers (CMPs) have become important precursors for environmental and energy applications, compared with inorganic electrode materials, due to their ease of preparation, facile charge storage process, π-conjugated structures, relatively high thermal and chemical stability, abundance in nature, and high surface areas. Therefore, in this study, we designed and prepared new benzobisthiadiazole (BBT)-linked CMPs (BBT-CMPs) using a simple Sonogashira couplings reaction by reaction of 4,8-dibromobenzo(1,2-c;4,5-c')bis(1,2,5)thiadiazole (BBT-Br2) with ethynyl derivatives of triphenylamine (TPA-T), pyrene (Py-T), and tetraphenylethene (TPE-T), respectively, to afford TPA-BBT-CMP, Py-BBT-CMP, and TPE-BBT-CMP. The chemical structure and properties of BBT-CMPs such as surface areas, pore size, surface morphologies, and thermal stability using different measurements were discussed in detail. Among the studied BBT-CMPs, we revealed that TPE-BBT-CMP displayed high degradation temperature, up to 340 °C, with high char yield and regular, aggregated sphere based on thermogravimetric analysis (TGA) and scanning electron microscopy (SEM), respectively. Furthermore, the Py-BBT-CMP as organic electrode showed an outstanding specific capacitance of 228 F g-1 and superior capacitance stability of 93.2% (over 2000 cycles). Based on theoretical results, an important role of BBT-CMPs, due to their electronic structure, was revealed to be enhancing the charge storage. Furthermore, all three CMP polymers featured a high conjugation system, leading to improved electron conduction and small bandgaps.


Assuntos
Polímeros , Pirenos , Eletrodos , Elétrons , Polímeros/química
8.
Langmuir ; 38(12): 3623-3629, 2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35291766

RESUMO

This Perspective describes how the fluorescence blob model (FBM) has been developed and applied over the past 30 years to characterize the long-range backbone dynamics (LRBD) of polymers in solution. In these experiments, the polymers are randomly labeled with the dye pyrene, which forms an excimer upon the encounter between an excited and a ground-state pyrenyl label inside a finite subvolume of the polymer coil referred to as a blob representing the volume probed by the excited pyrene. By compartmentalizing the polymer coil into a cluster of identical blobs, FBM analysis of the fluorescence decays acquired with the polymers yields the number Nblob of structural units inside a blob. Since a flexible or rigid backbone will result in an Nblob that is either large or small, Nblob can be used as a measure of the flexibility of a given polymer. After having established that these experiments based on pyrene excimer formation (PEF) yielded quantitative information about the LRBD of a variety of polymers in solution, control experiments were carried out to characterize the effects that different molecular variables, such as the side-chain size (SCS) of a structural unit or the length of the linker connecting pyrene to the polymeric backbone, had on the parameters retrieved with the FBM. At this point, the FBM was applied to study the LRBD of polypeptides prepared from racemic mixtures of amino acids (aa's). These studies led to the establishment of simple rules that could be developed into mathematical equations to describe the LRBD of polypeptides. The Nblob values retrieved from the FBM analysis of the fluorescence decays acquired with the pyrene-labeled polypeptides could then be employed to predict the total conformational search time (τtcs) of any polypeptide based on their sequence. Strong correlations were found between the predicted τtcs and the experimental folding times of 145 proteins. The good quality of these correlations suggests that the blob-based approach described in this report might represent an interesting mathematical means for studying protein folding.


Assuntos
Peptídeos , Pirenos , Polímeros , Pirenos/química , Espectrometria de Fluorescência
9.
Arch Microbiol ; 204(4): 227, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35353236

RESUMO

This study aimed to evaluate the differences in the characteristics of extracellular polymeric substances (EPSs) secreted by Mycobacterium gilvum SN12 (M.g. SN12) cultured on pyrene (Pyr) and benzo[a]pyrene (BaP). A heating method was used to extract EPSs from M.g. SN12, and the composition, emulsifying activity, and morphology of EPS extracts were investigated. Results showed that EPS extracts varied significantly with Pyr or BaP addition to the bacterial cultures. The concentration of proteins and carbohydrates, the main components of the EPS extracts, first increased and then decreased, with an increase in the concentration of Pyr (0-120 mg L-1) and BaP (0-120 mg L-1). A similar trend was observed for the emulsifying activity of the EPS extracts. EPSs extracted from all cultures exhibited a compact structure with a smooth surface, except for EPSs extracted from BaP-grown M.g. SN12, which revealed a more fragile and softer surface. These findings suggest that Pyr and BaP had different influences on the properties of isolated EPSs, providing insights into the mechanism underlying polycyclic aromatic hydrocarbons (PAHs) biodegradation by some EPS-secreting bacteria. To the best of our knowledge, this is the first report on the texture profile of EPS samples extracted from M.g. SN12 grown on PAHs.


Assuntos
Benzo(a)pireno , Hidrocarbonetos Policíclicos Aromáticos , Benzo(a)pireno/metabolismo , Matriz Extracelular de Substâncias Poliméricas/metabolismo , Micobactérias não Tuberculosas/metabolismo , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Pirenos/metabolismo
10.
Org Biomol Chem ; 20(13): 2704-2714, 2022 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-35293927

RESUMO

Novel pyrene-based double aza- and diaza[4]helicenes have been prepared through a five-step synthetic sequence in overall good yields. Commercially available 2,3-dihaloazines (2,3-dibromopyridine, 2,3-dichloropyrazine and 2,3-dichloroquinoxaline) were used as starting materials. The synthesis employs electrophile-induced cyclizations of ortho-alkynyl bihetaryls as the key steps, leading to the formation of a helical skeleton. To discern the effect of merging azine and pyrene moieties within a helical skeleton, the X-ray structures, UV-vis absorption and fluorescence spectra of the helicenes were investigated and compared with those of the parent [4]helicene, aza- and diaza[4]helicenes. It was found that the emission properties of the synthesized helicenes can be modulated as a function of pH. The basicity of pyrene-based double aza[4]helicenes was estimated by the direct fluorimetric titration method; the pKa value was found to be equal to 1.4.


Assuntos
Compostos Policíclicos , Concentração de Íons de Hidrogênio , Modelos Moleculares , Compostos Policíclicos/química , Pirenos
11.
Angew Chem Int Ed Engl ; 61(21): e202117212, 2022 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-35274429

RESUMO

An original 1-acetato-4-(1-pyrenyl)-1,4,7-triazacyclononane (AcPyTACN) was synthesized for the immobilization of a His-tagged recombinant CODH from Rhodospirillum rubrum (RrCODH) on carbon-nanotube electrodes. The strong binding of the enzyme at the Ni-AcPyTACN complex affords a high current density of 4.9 mA cm-2 towards electroenzymatic CO2 reduction and a high stability of more than 6×106  TON when integrated on a gas-diffusion bioelectrode.


Assuntos
Aldeído Oxirredutases , Complexos Multienzimáticos , Aldeído Oxirredutases/metabolismo , Compostos Aza , Dióxido de Carbono/metabolismo , Monóxido de Carbono/metabolismo , Histidina , Complexos Multienzimáticos/metabolismo , Níquel/metabolismo , Piperidinas , Pirenos
12.
J Fluoresc ; 32(3): 1059-1071, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35303237

RESUMO

A Fluorescent chemosensor based on pyrene scaffold, 5-diethylamino-2-(pyren-1-yliminomethyl)-phenol (PDS) is synthesized using condensation method. It displays novel aggregation-induced emission (AIE) phenomena in its aggregated/solid state. The AIE characteristic of PDS is studied in CH3CN/H2O mixtures at different volume percentage of water and morphology of the aggregated particles are investigated by DLS and optical fluorescence microscopic study. The probe is aggregated into ordered one-dimensional (1-D) rod like microcrystals and exhibit high efficiency of solid-state emission with green colour. By taking advantage of its interesting AIE feature, the aggregated hydrosol has been utilized as 'off-on' type fluorescence switching chemosensor with superb selectivity and sensitivity towards Cu2+ions and the limit of detection (LOD) was calculated as low as 6.3 µM. A high Stern-Volmer quenching constant was estimated to be 2.88 × 105 M-1. The proposed chemosensor with AIE feature reveals a prospective view for the on-site visual recognition of Cu2+ ions in fluorescent paper strips and the synthesized probe is also exploited to find out the concentration of Cu2+ions in real water samples.


Assuntos
Cobre , Corantes Fluorescentes , Cobre/química , Corantes Fluorescentes/química , Íons , Estudos Prospectivos , Pirenos , Espectrometria de Fluorescência , Água/química
13.
J Fluoresc ; 32(3): 1229-1238, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35353278

RESUMO

In this work, we introduce a highly selective and sensitive fluorescent sensor based on pyrene derivative for Fe(III) ion sensing in DMSO/water media. 2-(pyrene-2-yl)-1-(pyrene-2-ylmethyl)-1H-benzo[d]imidazole (PEBD) receptor was synthesized via simple condensation reaction and confirmed by spectroscopic techniques. The receptor exhibits fluorescence quenching in the presence of Fe(III) ions at 440 nm. ESI-MS and Job's method were used to confirm the 1:1 molar binding ratio of the receptor PEBD to Fe(III) ions. Using the Benesi-Hildebrand equation the binding constant value was determined as 8.485 × 103 M-1. Furthermore, the limit of detection (LOD, 3σ/K) value was found to be 1.81 µM in DMSO/water (95/5, v/v) media. According to the Environmental Protection Agency (EPA) of the United States, it is lower than the acceptable value of Fe3+ in drinking water (0.3 mg/L). The presence of 14 other metal ions such Co2+, Cr3+, Cu2+, Fe2+, Hg2+, Pb2+, K+, Ni2+, Mg2+, Cd2+, Ca2+, Mn2+, Al3+, and Zn2+ did not interfere with the detection of Fe(III) ions. The fluorescence life-time of the receptor PEBD with and without Fe3+ ion was found to be 1.097 × 10-9 s and 0.9202 × 10-9 s respectively. Similarly, the quantum yield of the receptor PEBD with Fe3+ and without Fe3+ ion was calculated, and found as 0.05 and 0.25 respectively. Computational studies of the receptor PEBD were carried out with density functional theory (DFT) using B3LYP/ 6-311G (d, p), LANL2DZ level of theory.


Assuntos
Compostos Férricos , Corantes Fluorescentes , Dimetil Sulfóxido , Corantes Fluorescentes/química , Íons , Pirenos , Espectrometria de Fluorescência , Água/química
14.
Mar Pollut Bull ; 178: 113578, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35344733

RESUMO

Cytochrome P450 1a (Cyp1a) is an important enzyme for metabolism of organic pollutants. To understand its reaction to polycyclic aromatic hydrocarbons (PAHs), we knocked out this gene in a marine model fish, Javanese medaka, Oryzias javanicus, using the CRISPR/Cas 9 system. A homozygous mutant (KO) strain with a four-base deletion was established using an environmental DNA (eDNA)-based genotyping technique. Subsequently, KO, heterozygous mutant (HT), and wild-type (WT) fish were exposed to model pollutants, pyrene and phenanthrene, and survivorship and swimming behavior were analyzed. Compared to WT, KO fish were more sensitive to pyrene, suggesting that Cyp1a transforms pyrene into less toxic metabolites. Conversely, WT fish were sensitive to phenanthrene, suggesting that metabolites transformed by Cyp1a are more toxic than the original compound. HT fish showed intermediate results. Thus, comparative use of KO and WT fish can distinguish modes of pollutant toxicity, providing a deeper understanding of fish catabolism of environmental pollutants.


Assuntos
Oryzias , Fenantrenos , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Animais , Citocromo P-450 CYP1A1/genética , Citocromo P-450 CYP1A1/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Indonésia , Oryzias/genética , Fenantrenos/metabolismo , Fenantrenos/toxicidade , Hidrocarbonetos Policíclicos Aromáticos/análise , Pirenos/metabolismo , Pirenos/toxicidade , Poluentes Químicos da Água/análise
15.
Chem Res Toxicol ; 35(4): 585-596, 2022 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-35347982

RESUMO

The gut microbiome is a key contributor to xenobiotic metabolism. Polycyclic aromatic hydrocarbons (PAHs) are an abundant class of environmental contaminants that have varying levels of carcinogenicity depending on their individual structures. Little is known about how the gut microbiome affects the rates of PAH metabolism. This study sought to determine the role that the gut microbiome has in determining the various aspects of metabolism in the liver, before and after exposure to two structurally different PAHs, benzo[a]pyrene and 1-nitropyrene. Following exposures, the metabolic rates of PAH metabolism were measured, and activity-based protein profiling was performed. We observed differences in PAH metabolism rates between germ-free and conventional mice under both unexposed and exposed conditions. Our activity-based protein profiling (ABPP) analysis showed that, under unexposed conditions, there were only minor differences in total P450 activity in germ-free mice relative to conventional mice. However, we observed distinct activity profiles in response to corn oil vehicle and PAH treatment, primarily in the case of 1-NP treatment. This study revealed that the repertoire of active P450s in the liver is impacted by the presence of the gut microbiome, which modifies PAH metabolism in a substrate-specific fashion.


Assuntos
Microbioma Gastrointestinal , Hidrocarbonetos Policíclicos Aromáticos , Animais , Benzo(a)pireno , Camundongos , Pirenos , Xenobióticos
16.
Sci Total Environ ; 822: 153539, 2022 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-35104532

RESUMO

The levels of organic pollutants, in particular polycyclic aromatic hydrocarbons (PAHs), are increasing worldwide, yet we lack clarity on how these pollutants affect microbial communities of different trophic levels, including protists, fungi, and bacteria. Herein, we conducted soil microcosm incubation experiments to investigate the effects of pyrene, a typical PAH, on microbial communities along concentration gradients from 0 to 500 mg kg-1 soil. Protistan communities were more sensitive to pollutants than fungal and bacterial communities, and protistan consumers and phototrophs were the dominant trophic functional groups. In addition, by assessing changes in the diversity and structure of the soil microbiome and ecological networks, we found that the microbial communities, including the protistan community and the two trophic communities composed of protists and their prey, were destabilized with increasing stress and pyrene concentrations. We identified links and complicated relationships between phototrophs, bacteria, and consumers in food webs, which explain the importance of protists in stabilizing the microbial community. Collectively, our work provides novel evidence that protists are considerably sensitive to pollution stress, and caution should be exercised in future evaluations of the protistan and multitrophic communities in polluted soil ecosystems.


Assuntos
Microbiota , Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Bactérias , Fungos , Pirenos/toxicidade , Solo , Microbiologia do Solo , Poluentes do Solo/toxicidade
17.
Chemosphere ; 296: 134059, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35189193

RESUMO

Micro- and nano-plastics (MNPs) are recognized as a class of emerging and ubiquitous contaminants in soil, which influence the behavior of pollutants and have potential adverse impacts on organisms. This study explored the potential mechanisms of polystyrene microplastics (MPs, 10 µm) and nanoplastics (NPs, 100 nm) with different concentrations (10 and 100 mg/kg) in soil on the accumulation and elimination of pyrene in earthworms, Eisenia fetida. MPs facilitated the accumulation of pyrene by earthworms in the first week via injuring the integrity of earthworm intestine. The representative antioxidant enzyme activities indicated that MPs induced severer oxidative stress to earthworms than NPs, especially at the concentration of 100 mg/kg, thus leading to increased accumulation of pyrene by earthworms at the initial stage. In addition, high-throughput 16S rRNA gene sequencing demonstrated that NPs inhibited the pyrene-degrading bacteria in earthworms, resulting in the higher concentration of pyrene in the end. The results elucidated the effects of MNPs with different sizes and concentrations on the accumulation of organic pollutants in the terrestrial invertebrates.


Assuntos
Oligoquetos , Poluentes do Solo , Animais , Microplásticos/toxicidade , Plásticos/farmacologia , Poliestirenos/farmacologia , Pirenos , RNA Ribossômico 16S , Solo , Poluentes do Solo/análise
18.
J Mater Chem B ; 10(10): 1641-1649, 2022 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-35194628

RESUMO

Herein, we discuss a new pyrene-based push-pull dye (PC) and our investigation of its photophysical properties and applicability to biological studies. The newly synthesized dye exhibits highly polarity-sensitive fluorescence over a significantly wide range (i.e., the green to far-red region), accompanied by high fluorescence quantum yields (ΦFL > 0.70 in most organic solvents) and superior photostability to that of the commonly used Nile Red (NR) dye, which also fluoresces in the green to red region. When human prostate cancer cells stained with PC were imaged using a confocal laser scanning fluorescence microscope, PC was found to selectively stain the lipid droplets. Under the cell conditions where the formation of droplets was inhibited, PC could be distributed to both the remaining droplets and the intercellular membranes, which could be distinguished based on the fluorescence solvatochromic function of PC. Furthermore, PC efficiently stained normal human skin tissue blocks treated with a transparency-enhancing agent and enabled clear visualization of individual cells in each tissue architecture by means of two-photon fluorescence microscopy (2PM). Interestingly, PC provides bright 2PM images under tissue-penetrative 960 nm excitation, realizing much clearer and deeper tissue imaging than conventional pyrene dyes and NR. These results suggest that PC could replace several commonly used dyes in various biological applications, particularly the rapid and accurate diagnosis of tissue diseases, typified by biopsy.


Assuntos
Corantes Fluorescentes , Pirenos , Células HeLa , Humanos , Gotículas Lipídicas , Microscopia de Fluorescência/métodos
19.
J Am Chem Soc ; 144(8): 3370-3375, 2022 03 02.
Artigo em Inglês | MEDLINE | ID: mdl-35188785

RESUMO

Bis-periazulene (cyclohepta[def]fluorene), which is an unknown pyrene isomer, was synthesized as kinetically protected forms. Its triaryl derivatives 1c-e exhibited the superimposed electronic structures of peripheral, polarized, and open-shell π-conjugated systems. In contrast to previous theoretical predictions, bis-periazulene derivatives were in the singlet ground state. Changing an aryl group controlled the energy gap between the lowest singlet-triplet states.


Assuntos
Fluorenos , Pirenos , Fluorenos/química , Isomerismo
20.
Molecules ; 27(3)2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35163953

RESUMO

Microbial degradation is a useful tool for inhibiting or preventing polycyclic aromatic hydrocarbons (PAHs) widely distributed in marine environment after oil spill accidents. This study aimed to evaluate the potential and diversity of bacteria Bacillus sp. PAH-2 on Benzo (a) anthracene (BaA), Pyrene (Pyr), and Benzo (a) pyrene (BaP), their composite system, aromatic components system, and crude oil. The seven-day degradation rates against BaA, Pyr, and BaP were 20.6%, 12.83%, and 17.49%, respectively. Further degradation study of aromatic components demonstrated PAH-2 had a high degradation rate of substances with poor stability of molecular structure. In addition, the degradation of PAHs in crude oil suggested PAH-2 not only made good use of PAHs in such a more complex structure of pollutants but the saturated hydrocarbons in the crude oil also showed a good application potential.


Assuntos
Bacillus/metabolismo , Recuperação e Remediação Ambiental/métodos , Hidrocarbonetos Policíclicos Aromáticos/química , Bactérias/metabolismo , Benzo(a)pireno/metabolismo , Biodegradação Ambiental , Petróleo/metabolismo , Poluição por Petróleo , Pirenos , Água do Mar
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