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1.
J Hazard Mater ; 423(Pt B): 127189, 2022 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-34555764

RESUMO

Bioaugmentation is an effective approach to remediate soils contaminated by polycyclic aromatic hydrocarbons (PAHs), but suffers from unsatisfactory performance in engineering practices, which is hypothetically explained by the complicated interactions between indigenous microbes and introduced degraders. This study isolated a cultivable pyrene degrader (Sphingomonas sp. YT1005) and an active pyrene degrading consortium (Gp16, Streptomyces, Pseudonocardia, Panacagrimonas, Methylotenera and Nitrospira) by magnetic-nanoparticle mediated isolation (MMI) from soils. Pyrene biodegradation was postponed in bioaugmentation with Sphingomonas sp. YT1005, whilst increased by 30.17% by the active pyrene degrading consortium. Pyrene dioxygenase encoding genes (nidA, nidA3 and PAH-RHDα-GP) were enriched in MMI isolates and positively correlated with pyrene degradation efficiency. Pyrene degradation by Sphingomonas sp. YT1005 only followed the phthalate pathway, whereas both phthalate and salicylate pathways were observed in the active pyrene degrading consortium. The results indicated that the uncultivable pyrene degraders were suitable for bioaugmentation, rather than cultivable Sphingomonas sp. YT1005. The negative correlations between Sphingomonas sp. YT1005 and the active-yet-uncultivable pyrene degraders were the underlying mechanisms of bioaugmentation postpone in engineering practices.

2.
J Hazard Mater ; 424(Pt B): 127532, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34879522

RESUMO

Linking chromium (Cr) speciation with its stability in soils is vital because insoluble Cr(VI) and chemically adsorbed Cr(VI) could hinder the remediation efficiency and release Cr(VI) for a prolonged period of time. In this study, we investigated key Cr species to probe the mechanisms controlling the release of insoluble Cr(VI) at Cr-contaminated sites using synchrotron-based X-ray absorption near-edge structure (XANES) for the first time. Chromite, stichtite and Cr-silicate were predominant forms of Cr(III). Insoluble Cr(VI) was hosted by layered double hydroxides (LDHs) such as brownmilerite and hydrotalcite. Anion competition tests documented a substitution of absorbed Cr(VI) by SO42- and NO3-. Acid extraction released 6.7-25.7% more Cr(VI) than anion extraction, possibly attributing to the erosion of LDH and CaCrO4 in calcite rather than Cr-bearing minerals. Brown and red soils released maximally 62% and 44% of total Cr(VI) by 10 mol/(kg soil) and 2 mol/(kg soil) of H+, respectively. SO42-, H2O and H+ contributed to more release of total Cr(VI) in brown soils (22%, 33% and 7%) than red soils (25%, 17% and 2%). More crystalline Cr structures were found after chemical stabilization, indicating a higher Cr stability in chemically stabilized soils. Cr and Mn exhibited an overlapped distribution pattern in both contaminated and chemically stabilized soils, hinting at the re-oxidation of Cr(III). Insoluble Cr(VI) could be released by acidic rainfalls and soil organic matters, posing potential threats to Cr long-term stability in field-scale remediation.

3.
Sci Total Environ ; : 152202, 2021 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-34890682

RESUMO

Benzo[a]pyrene (BaP) is a typical high-molecular-weight PAH with carcinogenicity. Rhizoremediation is commonly applied to remove soil BaP, but its mechanism remains unclear. The role of inducers in root exudates in BaP rhizoremediation is rarely studied. Here, to address this problem, we firstly investigated the effect of the inducer salicylic acid on BaP rhizoremediation, rhizosphere BaP degraders, and PAH degradation-related genes by combining DNA-stable-isotope-probing, high-throughput sequencing, and gene function prediction. BaP removal in the rhizosphere was significantly increased by stimulation with salicylic acid, and the rhizosphere BaP-degrading microbial community structure was significantly changed. Fourteen microbes were responsible for the BaP metabolism, and most degraders, e.g. Aeromicrobium and Myceligenerans, were firstly linked with BaP biodegradation. The enrichment of the PAH-ring hydroxylating dioxygenase (PAH-RHD) gene in the heavy fractions of all 13C-treatments further indicated their involvement in the BaP biodegradation, which was also confirmed by the enrichment of dominant PAH degradation-related genes (e.g. PAH dioxygenase and protocatechuate 3,4-dioxygenase genes) based on gene function prediction. Overall, our study demonstrates that salicylic acid can enhance the rhizosphere BaP biodegradation by altering the community structure of rhizosphere BaP-degrading bacteria and the abundance of PAH degradation-related genes, which provides new insights into BaP rhizoremediation mechanisms in petroleum-contaminated sites.

4.
J Hazard Mater ; : 127778, 2021 Nov 14.
Artigo em Inglês | MEDLINE | ID: mdl-34823960

RESUMO

Atrazine accumulation in agricultural soil is prone to cause serious environmental problems and pose risks to human health. Vermicomposting is an eco-friendly approach to accelerating atrazine biodegradation, but the roles of earthworm cast in the accelerated atrazine removal remains unclear. This work aimed to investigate the roles of earthworm cast in promoting atrazine degradation performance by comprehensively exploring the change in atrazine metabolites and bacterial communities. Our results showed that earthworm cast amendment significantly increased soil pH, organic matters, humic acid, fulvic acid and humin, and achieved a significantly higher atrazine removal efficiency. Earthworm cast addition also remarkably changed soil microbial communities by enriching potential soil atrazine degraders (Pseudomonadaceae, Streptomycetaceae, and Thermomonosporaceae) and introducing cast microbial degraders (Saccharimonadaceae). Particularly, earthworm casts increased the production of metabolites deethylatrazine and deisopropylatrazine, but not hydroxyatrazine. Some bacterial taxa (Gaiellaceaea and Micromonosporaceae) and humus (humic acid, fulvic acid and humin) were strongly correlated with atrazine metabolism into deisopropylatrazine and deethylatrazine, whereas hydroxyatrazine production was benefited by higher pH. Our findings verified the accelerated atrazine degradation with earthworm cast supplement, providing new insights into the influential factors on atrazine bioremediation in vermicomposting.

5.
J Hazard Mater ; : 127720, 2021 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-34810010

RESUMO

Phosphate (P) minerals and phosphate solubilizing fungi (PSF) play essential roles in lead (Pb) immobilization, but their roles in driving Pb bioavailability and ecological risks in red soil remains poorly understood. In this study, the inoculation of P. oxalicum and TCP successfully enhanced available P (AP) and urease concentrations in artificially Pb contaminated red soil. Combined P. oxalicum and TCP inoculation significantly reduced Pb bioavailability, bioaccessibility, leachability and mobility by increasing soil AP concentration and forming stable Pb-P compounds during the 21-day experiment. Soil AP and Pb bioavailability play an important role in shifting soil microbial communities induced by co-occurrence of P. oxalicum and TCP. Combined P. oxalicum and TCP could notably promote the relative abundances of predominant soil genus to enhance microbial resistance to soil Pb. Likewise, coexistence of P. oxalicum and TCP showed the highest biomass and better branch root development of Pb-stressed in lettuces (Lactuca sativa L.) in pot experiment, and significantly reduced up to 88.1% of Pb translocation from soil to root over control. The reductions of Pb translocation and accumulation in root in P. oxalicum + TCP treatment could enhance the oxidase activities and alleviate the oxidative damages of H2O2 and O2.- in shoot tissues. Our study provided strong evidence to use PSF associated with P materials for the stable and eco-friendly soil Pb remediation.

6.
Ecotoxicol Environ Saf ; 227: 112880, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34655883

RESUMO

Phosphorus (P) containing minerals are identified as effective Pb stabilizers in soil, while their low solubility limit the Pb immobilization efficiency. In this work, the combination of phosphate solubilizing fungi (PSF) Penicillium oxalicum and tricalcium phosphate (TCP) was constructed and applied to improve Pb immobilization stabilities in medium and soils. P. oxalicum+ TCP could significantly improve Pb2+ removal to above 99% under different TCP/Pb2+ and pH values. TCP and P. oxalicum could remarkably immobilize Pb by ion exchange, and PbC2O4 precipitation or surface adsorption, respectively. While the enhanced Pb immobilization in P. oxalicum+ TCP was explained by stronger Pb2+ interaction with tryptophan protein-like substances in extracellular polymeric substance, and the formation of the most stable Pb-phosphate compound hydroxypyromorphite (Pb5(PO4)3OH). Toxicity characteristic leaching procedure test showed that only 0.91% of Pb2+ was leachable in P. oxalicum+ TCP treatment, significantly lower than that in P. oxalicum (2.90%) and TCP (7.52%) treatments. In addition, the lowest soil exchangeable Pb fraction (37.1%) and the highest available soil P (88.0 mg/kg) were both found in P. oxalicum+ TCP treatment. By synergistically forming stable Pb-containing products, thus the combination of PSF and P minerals could significantly improve Pb2+ immobilization and stability in soils.


Assuntos
Penicillium , Poluentes do Solo , Fosfatos de Cálcio , Matriz Extracelular de Substâncias Poliméricas/química , Chumbo , Fosfatos/análise , Solo , Poluentes do Solo/análise
7.
Environ Microbiol ; 23(11): 7042-7055, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34587314

RESUMO

Rhizoremediation is a potential technique for polycyclic aromatic hydrocarbon (PAH) remediation; however, the catabolic pathways of in situ rhizosphere PAH degraders and the main factors driving PAH rhizoremediation remain unclear. To address these issues, stable-isotope-probing coupled with metagenomics and molecular ecological network analyses were first used to investigate the phenanthrene rhizoremediation by three different prairie grasses in this study. All rhizospheres exhibited a significant increase in phenanthrene removal and markedly modified the diversity of phenanthrene degraders by increasing their populations and interactions with other microbes. Of all the active phenanthrene degraders, Marinobacter and Enterobacteriaceae dominated in the bare and switchgrass rhizosphere respectively; Achromobacter was markedly enriched in ryegrass and tall fescue rhizospheres. Metagenomes of 13 C-DNA illustrated several complete pathways of phenanthrene degradation for each rhizosphere, which clearly explained their unique rhizoremediation mechanisms. Additionally, propanoate and inositol phosphate of carbohydrates were identified as the dominant factors that drove PAH rhizoremediation by strengthening the ecological networks of soil microbial communities. This was verified by the results of rhizospheric and non-rhizospheric treatments supplemented with these two substances, further confirming their key roles in PAH removal and in situ PAH rhizoremediation. Our study offers novel insights into the mechanisms of in situ rhizoremediation at PAH-contaminated sites.

8.
J Hazard Mater ; 419: 126471, 2021 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-34216972

RESUMO

Oil spillages lead to the formation of hydrocarbon and metal mixtures possessing effects on alkane-degrading bacteria that are responsible for the bioremediation of oil-contaminated soils and waters. Studies of bacterial responses to the mixture of petroleum and metal can inform appropriate strategies for bioremediation. We employed a luminescent bioreporter Acinetobacter baylyi ADPWH_recA with alkane degradation capability to evaluate the combined effects from heavy metals (Cd, Pb and Cu) and alkanes (dodecane, tetradecane, hexadecane and octadecane). Bioluminescent ratios of ADPWH_recA in single Cd or Pb treatments ranged from 0.25 to 1.98, indicating both genotoxicity and cytotoxicity of these two metals, while ratios < 1.0 postexposure to Cu showed its cytotoxic impacts on ADPWH_recA bioreporter. Metal mixtures exhibited enhanced antagonistic effects (Ti>4.0) determined by the Toxic Unit model. With 100 mg/L alkane, the morbidity of ADPWH-recA reduced to < 20%, showing the inhibition of alkanes on Cd toxicity. Exposed to the metal mixture containing 10 mg/L Cu, the weak binding affinity of Cu with alkanes contributed to a high morbidity of > 85% in ADPWH_recA cells. This study provides a new way to understand the toxicity of mixture contaminants, which can help to optimize treatment efficiencies of bacterial remediation for oil contamination.


Assuntos
Acinetobacter , Metais Pesados , Acinetobacter/genética , Alcanos/toxicidade , Hidrocarbonetos
9.
J Hazard Mater ; 415: 125727, 2021 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-34088197

RESUMO

Various remediation strategies have been developed to eliminate soil chromium (Cr) contamination which challenges the ecosystem and human health, and chemical stabilization is the most popular one. Limited work focuses on the change of soil microbial community and functions after chemical stabilization. The present study examined the diversity and structure of bacterial, fungal and archaeal communities in 20 soils from a Cr-contaminated site in China after chemical stabilization and ageing. Cr contamination significantly reduced microbial diversity and shaped microbial community structure. After chemical stabilization, bacterial and fungal communities had higher richness and evenness, whereas archaea behaved oppositely. Microbial community structure after stabilization were more similar to uncontaminated soils. Among all environmental variables, pH and Al explained 25.2% and 9.4% of the total variance of bacterial diversity, whereas the major variable affecting fungal community was pH (29.3%). Cr, organic matters, extractable-Al and moisture explained 25.8%, 22.4%, 9.9% and 9.9% of the total variance in archaeal community, respectively. This work for the first time unraveled the change of the whole soil microbial community structures and functions at Cr-contaminated sites after chemical stabilization on field scale and proved chemical stabilization as an effective approach to detoxicate Cr(VI) and recover microbial communities in soils.


Assuntos
Microbiota , Poluentes do Solo , China , Cromo/análise , Humanos , Solo , Microbiologia do Solo , Poluentes do Solo/análise
10.
Ecotoxicol Environ Saf ; 221: 112432, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34166937

RESUMO

The intensive and long-term use of atrazine in agriculture has resulted in serious environmental pollution and consequently endangered ecosystem and human health. Soil microorganisms play an important role in atrazine degradation. However, their degradation efficiencies are relatively low due to their slow growth and low abundance, and manure amendment as a practice to improve soil nutrients and microbial activities can solve these problems. This study investigated the roles of goat manure in atrazine degradation performance, metabolites and bacterial community structure. Our results showed that atrazine degradation efficiencies in un-amended soils were 26.9-35.7% and increased to 60.9-84.3% in goat manure amended treatments. Hydroxyatrazine pathway was not significantly altered, whereas deethylatrazine and deisopropylatrazine pathways were remarkably enhanced in treatments amended with manure by encouraging the N-dealkylation of atrazine side chains. In addition, goat manure significantly increased soil pH and contents of organic matters and humus, explaining the change of atrazine metabolic pathway. Nocardioides, Sphingomonas and Massilia were positively correlated with atrazine degradation efficiency and three metabolites, suggesting their preference in atrazine contaminated soils and potential roles in atrazine degradation. Our findings suggested that goat manure acts as both bacterial inoculum and nutrients to improve soil microenvironment, and its amendment is a potential practice in accelerating atrazine degradation at contaminated sites, offering an efficient, cheap, and eco-friendly strategy for herbicide polluted soil remediation.


Assuntos
Atrazina/metabolismo , Biodegradação Ambiental , Esterco/microbiologia , Microbiologia do Solo , Animais , Atrazina/análise , Bactérias/metabolismo , Ecossistema , Cabras , Herbicidas/análise , Herbicidas/metabolismo , Solo/química , Poluentes do Solo/análise , Poluentes do Solo/metabolismo
11.
Environ Int ; 155: 106591, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-33933901

RESUMO

Organophosphate esters (OPEs) are normally used as flame retardants, plasticizers and lubricants, but have become environmental pollutants. Because OPEs are normally present alongside heavy metals in soils, the effects of interactions between OPEs and heavy metals on plant uptake of OPEs need to be determined. In this study, we investigated the effects of OPEs chemical structure, plant cultivar and copper (Cu) on the uptake and translocation of OPEs by plants. The bioaccumulation of OPEs varied among plant cultivars. They were preferentially enriched in carrot, with the lowest concentrations observed in maize. OPEs with electron-ring substituents (ER-OPEs) exhibited a higher potential for root uptake than did OPEs with open-chain substituents (OC-OPEs), which could be attributed to the higher sorption of ER-OPEs onto root charged surfaces. This was explained by the stronger noncovalent interactions with the electron-rich structure of ER-OPEs. The presence of Cu slightly reduced the distinct difference in the ability of roots to take up OC-OPEs and ER-OPEs. This was explained by the interactions of Cu ions with the electron-rich structure of ER-OPEs, which suppressed the sorption of ER-OPEs on the root surface. A negative relationship between the logarithms of the translocation factor and octanol-water partition coefficient (Kow) was observed in treatments with either OPEs only or OPEs + Cu, implying the significant role of hydrophobicity in the OPEs acropetal translocation. The results will improve our understanding of the uptake and translocation of OPEs by plant cultivars as well as how the process is affected by the chemical structure of OPEs and Cu, leading to improvements in the ecological risk assessment of OPEs in the food chain.


Assuntos
Cobre , Retardadores de Chama , China , Monitoramento Ambiental , Ésteres , Organofosfatos , Estruturas Vegetais
12.
Water Res ; 200: 117243, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-34029872

RESUMO

The outbreak of coronavirus infectious disease-2019 (COVID-19) pneumonia challenges the rapid interrogation of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human and environmental samples. In this study, we developed an assay using surface enhanced Raman scattering (SERS) coupled with multivariate analysis to detect SARS-CoV-2 in an ultra-fast manner without any pretreatment (e.g., RNA extraction). Using silver-nanorod SERS array functionalized with cellular receptor angiotensin-converting enzyme 2 (ACE2), we obtained strong SERS signals of ACE2 at 1032, 1051, 1089, 1189, 1447 and 1527 cm-1. The recognition and binding of receptor binding domain (RBD) of SARS-CoV-2 spike protein on SERS assay significantly quenched the spectral intensities of most peaks and exhibited a shift from 1189 to 1182 cm-1. On-site tests on 23 water samples with a portable Raman spectrometer proved its accuracy and easy-operation for spot detection of SARS-CoV-2 to evaluate disinfection performance, explore viral survival in environmental media, assess viral decay in wastewater treatment plant and track SARS-CoV-2 in pipe network. Our findings raise a state-of-the-art spectroscopic tool to screen and interrogate viruses with RBD for human cell entry, proving its feasibility and potential as an ultra-fast detection tool for wastewater-based epidemiology.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Domínios Proteicos , Análise Espectral Raman , Glicoproteína da Espícula de Coronavírus
13.
Water Res ; 198: 117138, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33895589

RESUMO

Intensified sanitization practices during the recent coronavirus disease-2019 (COVID-19) led to the release of chlorine-based disinfectants in surface water, potentially triggering the formation of disinfection byproducts (DBPs) in the presence of dissolved organic nitrogen (DON). Thus, a comprehensive investigation of DON's spatial distribution and its association with DBP occurrence in the surface water is urgently needed. In this study, a total of 51 water samples were collected from two rivers and four lakes in May 2020 in Wuhan to explore the regional variation of nitrogen (N) species, DON's compositional characteristics, and the three classes of DBP occurrence. In lakes, 53.0% to 86.3% of N existed as DON, with its concentration varying between 0.3-4.0 mg N/L. In contrast, NO3--N was the dominant N species in rivers. Spectral analysis revealed that DON in the lakes contained higher humic and fulvic materials with higher A254, A253/A203, SUVA254, and PIII+IV/PI+II+V ratios, while rivers had higher levels of hydrophilic compounds. Trihalomethanes (THMs) were the most prevalent DBPs in the surface waters, followed by N-nitrosamines and haloacetonitriles (HANs). The levels of N-nitrosamines (23.1-97.4 ng/L) increased significantly after the outbreak of the COVID-19 pandemic. Excessive DON in the surface waters was responsible for the formation of N-nitrosamines. This study confirmed that the presence of DON in surface water could result in DBP formation, especially N-nitrosamines, when disinfectants were discharged into surface water during the COVID-19 pandemic.


Assuntos
COVID-19 , Desinfetantes , Poluentes Químicos da Água , Purificação da Água , Desinfecção , Halogenação , Humanos , Nitrogênio/análise , Pandemias , SARS-CoV-2 , Trialometanos/análise , Poluentes Químicos da Água/análise
14.
Artigo em Inglês | MEDLINE | ID: mdl-33903827

RESUMO

The recent outbreak of coronavirus disease 2019 (COVID-19) and concerns about several other pandemics in the 21st century have attracted extensive global attention. These emerging infectious diseases threaten global public health and raise urgent studies on unraveling the underlying mechanisms of their transmission from animals to humans. Although numerous works have intensively discussed the cross-species and endemic barriers to the occurrence and spread of emerging infectious diseases, both types of barriers play synergistic roles in wildlife habitats. Thus far, there is still a lack of a complete understanding of viral diffusion, migration, and transmission in ecosystems from a macro perspective. In this review, we conceptualize the ecological barrier that represents the combined effects of cross-species and endemic barriers for either the natural or intermediate hosts of viruses. We comprehensively discuss the key influential factors affecting the ecological barrier against viral transmission from virus hosts in their natural habitats into human society, including transmission routes, contact probability, contact frequency, and viral characteristics. Considering the significant impacts of human activities and global industrialization on the strength of the ecological barrier, ecological barrier deterioration driven by human activities is critically analyzed for potential mechanisms. Global climate change can trigger and expand the range of emerging infectious diseases, and human disturbances promote higher contact frequency and greater transmission possibility. In addition, globalization drives more transmission routes and produces new high-risk regions in city areas. This review aims to provide a new concept for and comprehensive evidence of the ecological barrier blocking the transmission and spread of emerging infectious diseases. It also offers new insights into potential strategies to protect the ecological barrier and reduce the wide-ranging risks of emerging infectious diseases to public health.

15.
Anal Chem ; 93(12): 5098-5106, 2021 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-33728890

RESUMO

Human health is at great risk due to the spreading of antimicrobial resistance (AMR). The lengthy procedure of conventional antimicrobial susceptibility testing (AST) usually requires a few days. We developed a fast Raman-assisted antibiotic susceptibility test (FRAST), which detects single bacterial metabolic activity in the presence of antibiotics, using Raman single-cell spectroscopy. It was found that single-cell Raman spectra (SCRS) would show a clear and distinguishable Raman band at the "silent zone" (2000-2300 cm-1), due to the active incorporation of deuterium from heavy water (D2O) by antibiotic-resistant bacteria. This pilot study has compared the FRAST and the conventional AST for six clinical standard quality controls (four Gram-negative and two Gram-positive bacteria strains) in response to 38 antibiotics. In total, 3200 treatments have been carried out and approximately 64 000 SCRS have been acquired for FRAST analysis. The result showed an overall agreement of 88.0% between the FRAST and the conventional AST assay. The gram-staining classification based on the linear discriminant analysis (LDA) model of SCRS was developed, seamlessly coupling with the FRAST to further reduce the turnaround time. We applied the FRAST to real clinical analysis for nine urinary infectious samples and three sepsis samples. The results were consistent with MALDI-TOF identification and the conventional AST. Under the optimal conditions, the "sample to report" of the FRAST could be reduced to 3 h for urine samples and 21 h for sepsis samples. The FRAST provides fast and reliable susceptibility tests, which could speed up microbiological analysis for clinical practice and facilitate antibiotic stewardship.


Assuntos
Antibacterianos , Bactérias , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos , Humanos , Testes de Sensibilidade Microbiana , Projetos Piloto
16.
Biology (Basel) ; 10(2)2021 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-33671192

RESUMO

Phosphorus (P) is a vital element in biological molecules, and one of the main limiting elements for biomass production as plant-available P represents only a small fraction of total soil P. Increasing global food demand and modern agricultural consumption of P fertilizers could lead to excessive inputs of inorganic P in intensively managed croplands, consequently rising P losses and ongoing eutrophication of surface waters. Despite phosphate solubilizing microorganisms (PSMs) are widely accepted as eco-friendly P fertilizers for increasing agricultural productivity, a comprehensive and deeper understanding of the role of PSMs in P geochemical processes for managing P deficiency has received inadequate attention. In this review, we summarize the basic P forms and their geochemical and biological cycles in soil systems, how PSMs mediate soil P biogeochemical cycles, and the metabolic and enzymatic mechanisms behind these processes. We also highlight the important roles of PSMs in the biogeochemical P cycle and provide perspectives on several environmental issues to prioritize in future PSM applications.

17.
J Hazard Mater ; 412: 125212, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-33524732

RESUMO

This study explored the change of tetracycline degradation efficiency, metabolic pathway, soil physiochemical properties and degraders in vermiremediation by two earthworm species of epigeic Eisenia fetida and endogeic Amynthas robustus. We found a significant acceleration of tetracycline degradation in both earthworm treatments, and 4-epitetracycline dehydration pathway was remarkably enhanced only by vermiremediation. Tetracycline degraders from soils, earthworm intestines and casts were different. Ralstonia and Sphingomonas were potential tetracycline degraders in soils and metabolized tetracycline through direct dehydration pathway. Degraders in earthworm casts (Comamonas, Acinetobacter and Stenotrophomonas) and intestines (Pseudomonas and Arthrobacter) dehydrated 4-epitetracycline into 4-epianhydrotetracycline. More bacterial lineages resisting tetracycline were found in earthworm treatments, indicating the adaptation of soil and intestinal flora under tetracycline pressure. Earthworm amendment primarily enhanced tetracycline degradation by neutralizing soil pH and consuming organic matters, stimulating both direct dehydration and epimerization-dehydration pathways. Our findings proved that vermicomposting with earthworms is effective to alter soil microenvironment and accelerate tetracycline degradation, behaving as a potential approach in soil remediation at tetracycline contaminated sites.


Assuntos
Oligoquetos , Poluentes do Solo , Animais , Bactérias/genética , Solo , Poluentes do Solo/análise , Tetraciclina
18.
J Agric Food Chem ; 69(7): 2062-2068, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33555873

RESUMO

Plant uptake and translocation of perfluorooctane sulfonate (PFOS) are critical for food safety and raise major concerns. However, those processes are associated with many undisclosed mechanisms, especially when PFOS coexist with heavy metals. In this study, we investigated the effect of copper (Cu) on PFOS distribution in maize tissues by assessing the PFOS concentration and enantioselectivity. The presence of <100 µmol/L Cu exerted a limited effect on PFOS bioaccumulation, while >100 µmol/L Cu damaged the root cell membrane and increased root permeability, resulting in a higher PFOS concentration in roots. The suppression of acropetal translocation might be attributed to Cu inhibition of carrier proteins. The enantiomer fraction (EF) of 1m-PFOS at <100 µmol/L Cu was higher than that in a commercial product (0.5). Racemic PFOS was detected at >100 µmol/L Cu in roots and the EF variation changed from positive to negative in shoots. These EF results evidenced the existence of a protein-mediated uptake pathway. Besides, this study indicated the challenge of chiral signature application in PFOS source identification, given the effects of heavy metals and plants on PFOS enantioselectivity. The findings provide insight into PFOS bioaccumulation in plants cocontaminated with Cu and will facilitate environmental risk assessment.


Assuntos
Ácidos Alcanossulfônicos , Fluorcarbonetos , Cobre , Zea mays
19.
Chemosphere ; 262: 127852, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32768757

RESUMO

Ethidium bromide (3,8-diamino-6-phenyl-5-ethylphenanthridinium bromide, EtBr) is a carcinogenic compound widely used for staining nucleic acids that is difficult to treat. In this study, magnetic nanocatalysts (MNCs) were synthesized for the heterogeneous Fenton-like degradation of EtBr. The initial pH, MNC content, and H2O2 concentration were the key factors affecting the EtBr degradation performance and dynamics. An EtBr removal efficiency of 98.97% was achieved within 4 h under optimal conditions (initial pH, 3.0; MNC content, 1 g/L; H2O2 concentration, 50 mM), and the degradation followed the ring-open pathway with (2E,4Z,8E)-3-amino-N-ethyl-7,9-dihydroxynona-2,4,8-trienamide as an intermediate, as determined by liquid chromatography and mass spectrometry (LC/MS). Unexpected and satisfactory Fenton-like oxidation of EtBr occurred under basic conditions, which was explained by a novel denitration pathway with 2-[nitro(phenyl)methyl]-(1,1'-biphenyl)-4,4'-diamine as an intermediate. The MNCs retained 62.17% of their degradation efficiency after five consecutive reaction and harvest cycles. Our work elucidated the mechanisms and pathways of EtBr removal in a Fenton-like reaction using MNCs, and comprehensively discussed the optimal reaction conditions and its potential for re-use.


Assuntos
Etídio/química , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Fenômenos Magnéticos , Espectrometria de Massas , Oxirredução
20.
Environ Pollut ; 268(Pt B): 115807, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33096390

RESUMO

It is well-accepted that phosphorus, particularly orthophosphate, is a determinant factor in aquatic eutrophication. However, numerous kinds of phosphorus sources exist in real world scenario, and limited studies have characterized the pairwise relationships among abundant different phosphorus sources and the physiological behaviour of algae. The present study developed a high-throughput assay to investigate the effects of 59 different phosphorus sources (equal initial concentration of total phosphorus) on the growth and alkaline phosphatase (AKP) activities of Microcystis aeruginosa, a model cyanobacteria whose predominance holds sway in lake eutrophication. M. aeruginosa cultivated with nucleoside monophosphates (NMPs) had higher growth, relative AKP activities and residual orthophosphate, which were positively intercorrelated. Oppositely, non-NMPs cultivation of M. aeruginosa led to negative relationships between the relative AKP activities and their growth or residual orthophosphate. These results indicated distinct mechanisms for M. aeruginosa to utilize different phosphorus sources in real-world scenario, and both phosphorus source and content are determinant factors on the growth and physiological behaviour of M. aeruginosa. Given the complicated and vast phosphorus pool in the natural environment, phosphorus resources might significantly alter the abundance and physiological behaviour of M. aeruginosa and other bloom-forming algae, then influence the phytoplanktonic community structure and affect the possibility and intensity of algal bloom. Our work hints the underestimation of the restriction factors in lake eutrophication and provides a new tool to study the driven forces of phytoplanktonic community dynamics as phosphorus from both internal and external sources.


Assuntos
Microcystis , Fosfatase Alcalina , Eutrofização , Lagos , Fósforo
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