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Bioresource Technology Jul 2024Immobilization technology is a promising way to improve effectiveness and stability of microbial remediation for polycyclic aromatic hydrocarbons (PAHs), in which...
Immobilization technology is a promising way to improve effectiveness and stability of microbial remediation for polycyclic aromatic hydrocarbons (PAHs), in which carrier material is one of key factors restricting removal efficiency. In this study, fulvic acid-wheat straw biochar (FA/WS) composites were applied for immobilization of an efficient PAHs degrading bacterium Stenotrophomonas maltophilia (SPM). FA/WS&SPM showed superior degradation capacity than free bacteria and biochar-immobilized bacteria, with the removal efficiency of pyrene (20 mg L) reaching 90.5 % (7 days). Transcriptome analysis revealed that FA in the carrier materials can promote transportation and degradation of pyrene, and cell growth, as well as inhibit cell apoptosis. Enzyme activity and degradation products detection showed that SPM utilized both phthalic acid and salicylic acid metabolic pathways to degrade pyrene. Practicality of FA/WS&SPM for different kinds of PAHs remediation had been verified in contaminated soil, demonstrating a great potential in the field of PAHs polluted sites remediation.
Topics: Stenotrophomonas maltophilia; Pyrenes; Biodegradation, Environmental; Benzopyrans; Cells, Immobilized; Charcoal
PubMed: 38763203
DOI: 10.1016/j.biortech.2024.130857 -
Environmental Pollution (Barking, Essex... Nov 2021Bio-stimulation of the indigenous microbial community is considered as an effective strategy for the bioremediation of polluted environments. This examination explored...
Bio-stimulation of the indigenous microbial community is considered as an effective strategy for the bioremediation of polluted environments. This examination explored the near effects of various bio-stimulants on pyrene degradation, prokaryotic community compositions, and functions using 16S rRNA amplicon sequencing and qPCR. At first, the results displayed significant differences (p < 0.05) between the prokaryotic community structures of the control group, PYR (contains pyrene only), and bio-stimulants amended groups. Among the bio-stimulants, biochar, oxalic acid, salicylate, NPK, and ammonium sulfate augmented the pyrene degradation potential of microbial communities. Moreover, the higher abundance of genera, such as Flavobacterium, Hydrogenophaga, Mycobacterium, Rhodococcus, Flavihumibacter, Pseudomonas, Novosphingobium, etc., across the treatments indicated that these genera play a vital role in pyrene metabolism. Based on the higher abundance of GP-RHD and nidA genes, we speculated that Gram-positive prokaryotic communities are more competent in pyrene dissipation than Gram-negative. Furthermore, the marked abundance of nifH, and pqqC genes in the NPK and SA treatments, respectively, suggested that different bio-stimulants might enrich certain bacterial assemblages. Besides, the significant distinctions (p < 0.05) between the bacterial consortia of HA (humic acid) and SA (sodium acetate) groups from NPK, OX (oxalic acid), UR (urea), NH4, and SC (salicylate) groups also suggested that different bio-stimulants might induce distinct ecological impacts influencing the succession of prokaryotic communities in distinct directions. This work provides new insight into the bacterial degradation of pyrene using the bio-stimulation technique. It suggests that it is equally important to investigate the community structure and functions along with studying their impacts on degradation when devising a bio-stimulation technology.
Topics: Biodegradation, Environmental; Mycobacterium; Polycyclic Aromatic Hydrocarbons; Pyrenes; RNA, Ribosomal, 16S
PubMed: 34352636
DOI: 10.1016/j.envpol.2021.117863 -
Scientific Reports Jan 2021Pyrene and chromium (Cr(VI)) are persistent pollutants and cause serious environmental problems because they are toxic to organisms and difficult to remediate. The...
Pyrene and chromium (Cr(VI)) are persistent pollutants and cause serious environmental problems because they are toxic to organisms and difficult to remediate. The toxicity of pyrene and Cr(VI) to three crops (cotton, soybean and maize) was confirmed by the significant decrease in root and shoot biomass during growth in pyrene/Cr(VI) contaminated hydroponic solution. Two bacterial strains capable of simultaneous pyrene biodegradation and Cr(VI) reduction were isolated and identified as Serratia sp. and Arthrobacter sp. A mixture of the isolated strains at a ratio of 1:1 was more efficient for biotreatment of pyrene and Cr(VI) than either strain alone; the mixture effectively carried out bioremediation of contaminated water in a hydroponic system mainly through pyrene biodegradation and Cr(VI) reduction. Application of these isolates shows potential for practical microbial remediation of pyrene and Cr(VI) combined water pollution.
Topics: Arthrobacter; Biodegradation, Environmental; Chromium; Coculture Techniques; Pyrenes; Serratia; Water Pollutants, Chemical; Water Purification
PubMed: 33420172
DOI: 10.1038/s41598-020-80053-2 -
Chembiochem : a European Journal of... Mar 2022In this study, we investigated the photoreaction of U in a pyrene-labeled DNA duplex, RNA duplex, and DNA/RNA hybrids. We found that the photoreactivity of U changed...
In this study, we investigated the photoreaction of U in a pyrene-labeled DNA duplex, RNA duplex, and DNA/RNA hybrids. We found that the photoreactivity of U changed dramatically from hydrogen abstraction to cross-linking by changing the conformation of the duplex from the B-form to the A-form. Among three A-form structures, the largest amount of cross-linked products was observed when U was incorporated into the RNA strand and the pyrene was conjugated to the 5' end of the DNA. These results indicate that the contact manner of pyrene was different between A- and B-form duplexes. This is a rare example of the use of the reactivity of bromouracil to analyze the contact between a small molecule with a weak binding affinity and a nucleic acid.
Topics: Circular Dichroism; DNA; Nucleic Acid Conformation; Pyrenes; RNA
PubMed: 35080796
DOI: 10.1002/cbic.202100626 -
Chemosphere Jan 2022Polycyclic aromatic hydrocarbons (PAHs) are important mutagen prevalent in the contaminated sites, bringing potential risks to human health. Iron oxides are important...
Polycyclic aromatic hydrocarbons (PAHs) are important mutagen prevalent in the contaminated sites, bringing potential risks to human health. Iron oxides are important natural components in soils. Pyrene removal in soil using persulfate (PS) oxidation activated by microwave (MW) and magnetite (FeO) was investigated. FeO significantly promoted pyrene removal in the soil; 91.7 % of pyrene was degraded within 45 min treatment. Pyrene removal rate in the FeO/MW/PS system was 5.18 and 3.00 times higher than that in the FeO/PS and MW/PS systems. Increasing in FeO dosage, PS concentration, MW temperature, and soil moisture content in the selected range were conducive for pyrene degradation. SO, OH, O, and O were responsible for pyrene degradation, and the conversion of Fe (Ⅱ) in the FeO to Fe (Ⅲ) contributed to the formation of O and O. Characteristic bands of pyrene were more obviously destroyed by the FeO/MW/PS oxidation, in comparison with MW/PS oxidation. Ring hydroxylation and ring-opening reactions were the main degradation pathways of pyrene. The toxicities of the formed byproducts were significantly reduced after treatment. This study provided a promising option for pyrene contaminated soil remediation.
Topics: Environmental Restoration and Remediation; Ferrosoferric Oxide; Humans; Microwaves; Pyrenes; Soil; Soil Pollutants
PubMed: 34365168
DOI: 10.1016/j.chemosphere.2021.131787 -
International Journal of Environmental... Sep 2022In soil, polycyclic aromatic hydrocarbons (PAHs) are tightly bound to organic components, but surfactants can effectively transform them from a solid to a liquid phase....
In soil, polycyclic aromatic hydrocarbons (PAHs) are tightly bound to organic components, but surfactants can effectively transform them from a solid to a liquid phase. In this study, the biosurfactant rhamnolipid (RL) was selected as the eluent; shaking elution in a thermostatic oscillator improved the elution rate of pyrene, and the effects of RL concentration, temperature, and elution time on the elution effect were compared. After four repeated washings, the maximum elution rate was 75.6% at a rhamnolipid concentration of 20 g/L and a temperature of 45 °C. We found that 38 μm Zero-Valent Iron (ZVI) had a higher primary reaction rate (0.042 h), with a degradation rate of 94.5% when 3 g/L ZVI was added to 21 mM NaSO at 60 °C. Finally, electron paramagnetic resonance (EPR) detected DMPO-OH and DMPO-SO signals, which played a major role in the degradation of pyrene. Overall, these results show that the combination of rhamnolipid elution and persulfate oxidation system effectively remediated pyrene-contaminated soil and provides some implications for the combined remediation with biosurfactants and chemical oxidation.
Topics: Biodegradation, Environmental; Glycolipids; Iron; Polycyclic Aromatic Hydrocarbons; Pyrenes; Sodium Compounds; Soil; Soil Pollutants; Sulfates; Surface-Active Agents
PubMed: 36141785
DOI: 10.3390/ijerph191811518 -
Chemosphere Jun 2022Micro- 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...
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.
Topics: Animals; Microplastics; Oligochaeta; Plastics; Polystyrenes; Pyrenes; RNA, Ribosomal, 16S; Soil; Soil Pollutants
PubMed: 35189193
DOI: 10.1016/j.chemosphere.2022.134059 -
Molecules (Basel, Switzerland) Feb 2023π-Extended pyrene compounds possess remarkable luminescent and semiconducting properties and are being intensively investigated as electroluminescent materials for...
π-Extended pyrene compounds possess remarkable luminescent and semiconducting properties and are being intensively investigated as electroluminescent materials for potential uses in organic light-emitting diodes, transistors, and solar cells. Here, the synthesis of two sets of pyrene-containing π-conjugated polyaromatic regioisomers, namely 2,3,10,11,14,15,20,21-octaalkyloxypentabenzo[,,,,]pentaphene () and 2,3,6,7,13,14,17,18-octaalkyloxydibenzo[,]phenanthro [9,10-]picene (), is reported. They were obtained using the Suzuki-Miyaura cross-coupling in tandem with Scholl oxidative cyclodehydrogenation reactions from the easily accessible precursors 1,8- and 1,6-dibromopyrene, respectively. Both sets of compounds, equipped with eight peripheral aliphatic chains, self-assemble into a single hexagonal columnar mesophase, with one short-chain homolog also exhibiting another columnar mesophase at a lower temperature, with a rectangular symmetry; isomers also possess wider mesophase ranges and higher mesophases' stability than their homologs. These polycyclic aromatic hydrocarbons all show a strong tendency of face-on orientation on the substrate and could be controlled to edge-on alignment through mechanical shearing of interest for their implementation in photoelectronic devices. In addition, both series and display green-yellow luminescence, with high fluorescence quantum yields, around 30%. In particular, exhibit a blue shift phenomenon in both absorption and emission with respect to their isomers. DFT results were in good agreement with the optical properties and with the stability ranges of the mesophases by confirming the higher divergence from the flatness of compared with . Based on these interesting properties, these isomers could be potentially applied not only in the field of fluorescent dyes but also in the field of organic photoelectric semiconductor materials as electron transport materials.
Topics: Pyrenes; Polycyclic Aromatic Hydrocarbons; Electron Transport; Fluorescence; Poly A
PubMed: 36838709
DOI: 10.3390/molecules28041721 -
Chemosphere Jan 2021Some rhizosphere bacteria could colonize on the root surface of plants, or even form biofilm to promote plant growth, enhance plant resistance to harsh external...
Some rhizosphere bacteria could colonize on the root surface of plants, or even form biofilm to promote plant growth, enhance plant resistance to harsh external environments and block the soil contamination. In this study, to explore the effects of pyrene-degrading bacterium on root surface on plant uptake of pyrene, a pyrene-degrading bacterium Mycolicibacterium sp. Pyr9 was isolated from the root surface of Eleusine indica L. Gaertn. in PAH-contaminated fields; after antibiotic labeling, it was colonized onto the root surface of white clover (Trifolium repens L.), and its distribution and performance were monitored under different levels of pyrene contamination. Strain Pyr9 could degrade 98% of pyrene (with an initial concentration of 50 mg L) in culture solution within 8 d; it also owns a variety of plant growth promoting characteristics and appreciable tolerance to harsh environments. The transcription of pyrene catabolic genes in Pyr9 enhanced obviously when induced by pyrene. Pyr9 colonized and grew well on the root surface of white clover via root inoculation; some cells could even enter into the root tissues and move to the shoots. Compared with the Pyr9-free treatment, the pyrene contents in the roots and shoots of Pyr9-inoculated white clover decreased by 25%-30% and 33%-42%, respectively. Correspondingly, the pyrene accumulation and translocation factors in white clover decreased as well. These results indicate that Pyr9 would be a good potential to circumvent plant pyrene pollution. This research may provide a theoretical basis and technical support for the safety of agricultural products and human health in PAH-contaminated sites.
Topics: Bacteria; Biodegradation, Environmental; Humans; Medicago; Plant Roots; Pyrenes; Soil Pollutants; Trifolium
PubMed: 32822944
DOI: 10.1016/j.chemosphere.2020.127918 -
Environmental Technology Jun 2020Pyrene is one of the polycyclic aromatic hydrocarbons, which are a potential threat to ecosystems due to their mutagenicity, carcinogenicity, and teratogenicity. In this...
Pyrene is one of the polycyclic aromatic hydrocarbons, which are a potential threat to ecosystems due to their mutagenicity, carcinogenicity, and teratogenicity. In this study, several bacteria were isolated from oil contaminated sludge and their capacity to biodegrade pyrene was investigated. Of these bacteria, the monoculture strain LZ6 showed the highest pyrene anaerobic biodegradation rate of 33% after 30 days when the initial concentration was 50 mg/L, and was identified as sp. LZ6 by morphological observation, the GENIII technology of Biolog, and 16S rDNA gene sequence analysis. The influence of various culture parameters on the biodegradation of pyrene were evaluated, and sp. LZ6 all showed the high degradation rate at an inoculum of 10-20% (v/v), pH 6.0-8.4, temperature 30-38°C, and initial pyrene concentration of 50-150 mg/L. The intermediate metabolites of the anaerobic biodegradation were analyzed by GC-MS. Several metabolites were identified, such as pyrene, 4,5-dihydro-, phenanthrene, dibenzo-p-dioxin, and 4-hydroxycinnamate acid. The anaerobic metabolic pathway for the degradation of pyrene was inferred by the products. It seems that pyrene was first reduced to pyrene,4,5-dihydro- by the adding of two hydrogen atoms, and then the carbon-carbon bond cleavage at saturated carbon atoms generated phenanthrene.
Topics: Anaerobiosis; Biodegradation, Environmental; Ecosystem; Klebsiella; Metabolic Networks and Pathways; Polycyclic Aromatic Hydrocarbons; Pyrenes
PubMed: 30522413
DOI: 10.1080/09593330.2018.1556348