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1.
Sci Total Environ ; 922: 171038, 2024 Apr 20.
Article in English | MEDLINE | ID: mdl-38378058

ABSTRACT

Sea level rise and extreme weather conditions caused by climatic changes enhance the frequency and length of submersion events in coastal soils, causing deposited airborne dusts to get in contact with marine salts. The behaviour of Cd, Zn and Pb from pedogenetic minerals and from dusts from mining and smelting activities, added to two soils under different agricultural management (arable and grassland) was examined after soil flooding for 1, 7 and 30 days with waters of increasing salinities (0, 4.37, 8.75, 17.25 and 34.5 g L-1). A rain water event following 1 d flooding released an extra amount of metals. Concentration of potentially toxic elements (PTE), pH, dissolved inorganic and organic C were measured in solutions collected by gravity from soil columns. Speciation distribution of leached metals and oversaturation parameters were calculated by Visual Minteq 3.0 and showed that complexation by chloride ions for Cd and fulvic acids for Pb were the drivers of solubilisation, while Zn interacted with both. Results showed that marine salts enhance up to 300 times leaching of Cd, and several times that of Zn and Pb from contaminated soils and that airborne toxic elements are much more mobilized than pedogenic ones. Smelter exhaust metals, particularly Pb, were made more mobile than those in mine tailings (up to 55 against 0.7 ng µg-1 Pb). Soil management strongly also influence mobilization by saline water: much lower amounts were leached from the grassland soil. Soil organic matter quality (DOC and humification) affects the extent of mobilization. The length of the flooding period did not result in coherent time trend patterns for the three metals, probably because of the multiple changes in solution parameters, but leached metals were always highly linearly correlated negatively with pH and positively with DOC.

2.
Environ Sci Pollut Res Int ; 31(4): 5331-5343, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38114695

ABSTRACT

The removal of copper (Cu) in soils by green technology is less treated with urgency, as it is a plant micronutrient. We examined the efficiency of Cu shoot accumulation by herbaceous plants in Cu-contaminated and non-contaminated soils in Trhové Dusniky and Podles, respectively, in the Czech Republic. The total soil Cu content of 81 mg kg-1 in Trhové Dusniky indicated a slight contamination level compared to 50 mg kg-1, the permissible value by WHO, and < 35 in Podlesí, representing a clean environment. The Cu content was above the permissible value in plants (10 mg kg-1 by WHO) in herbaceous speciesat the control site without trees: Stachys palustris L. (10.8 mg kg-1), Cirsium arvense L. (11.3 mg kg-1), Achillea millefolium L. (12.1 mg kg-1), Anthemis arvense L. (13.2 mg kg-1), and Calamagrostis epigejos L. (13.7 mg kg-1). In addition, Hypericum maculatum Crantz (10.6 mg kg-1), Campanula patula L. (11.3 mg kg-1), C. arvense (15 mg kg-1), and the highest accumulation in shoot of Equisetum arvense L. (37.1 mg kg-1), all under the canopy of trees at the uncontaminated site, were above the WHO value. Leucanthemum Vulgare (Lam.) and Plantago lanceolata L. recorded 11.2 mg kg-1 and 11.5 mg kg-1, respectively, in the soil of the Cu-contaminated site. These herbaceous species can support the phyto-management of Cu-contaminated soils, especially E. arvense. Critical attention is well-required in the medicinal application of herbaceous plants in treating human ailments due to their Cu accumulation potentials above the threshold. Spontaneous surveys and analysis of Cu speciation in herbaceous species can reveal suitable plants to decontaminate soils and provide caution on consumable products, especially bioactive compounds.


Subject(s)
Soil Pollutants , Trace Elements , Humans , Copper/analysis , Soil Pollutants/analysis , Plants , Trace Elements/analysis , Soil , Trees , Biodegradation, Environmental
3.
Chemosphere ; 286(Pt 2): 131755, 2022 Jan.
Article in English | MEDLINE | ID: mdl-34365173

ABSTRACT

Humic substances (HS) possess redox active groups covering a wide range of potentials and are used by facultative anaerobic microorganisms as electron acceptors. To serve as suitable electron shuttles for anaerobic respiration, HS should be able to re-oxidize relatively quickly to prevent polarization of the surrounding medium. Mediated electrochemical oxidation and decolorization assays, based on the reduction of the radical ion of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS•-) allow to determine the electron donating capacity (EDC) of HS, but uncertainties remain about the reaction time that should be allowed to obtain environmentally meaningful EDC values. In this work, we performed a kinetic analysis of the time trend of the reduction of ABTS•- by HS by Vis and Electron Paramagnetic Resonance (EPR) spectroscopies and by cyclic voltammetry. We found evidences of two concomitant separate mechanisms of electron exchange: a fast and a slow transfer processes which may have different environmental roles. These results can set a base to identify the appropriate conditions for the spectrophotometric determination of the fast and slow components of the EDC of HS.


Subject(s)
Electrons , Humic Substances , Electron Transport , Humic Substances/analysis , Kinetics , Oxidation-Reduction
4.
Iran J Biotechnol ; 19(3): e2722, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34825012

ABSTRACT

BACKGROUND: Sclerotinia sclerotiorum (Lib.) de Bary cause a deleterious disease on sunflower plants. Oxalic acid is the main pathogenicity factor of S. sclerotiorum. Two dimensional gel electrophoresis and mass spectrometry have been used in several studies to investigate molecular changes that occur in the plants in response to S. sclerotiorum infection. Comparing responses of resistant and susceptible lines upon pathogen infection provided novel information regarding defense mechanisms against this necrotrophic pathogen. OBJECTIVES: The present study reports proteome changes of partially resistant and susceptible sunflower lines under pathogen's culture filtrate treatment, resulting in the characterization of up- and down- regulated proteins. MATERIAL AND METHODS: Sunflower partially resistant and susceptible lines with two true leaves were exposed to fungus culture filtrate. The stems of treated and untreated plants were sampled at 24, 48 and 72 hours after treatment for two-dimensional electrophoresis. Twenty spots showed more than 1.5-fold change in abundance were subjected to MALDI/TOF-TOF MS for further analysis. RESULTS: The identified proteins were categorized into several classes including carbohydrate and energy metabolism (25%), cellular metabolic process (15%), stress response (15%), plant cell wall biogenesis (10%), photosynthesis (10%), protein metabolism (10%), unknown function (10%) and redox homeostasis (5%). CONCLUSIONS: Our proteomic investigation demonstrates an increase in the expression of proteins only in partially resistant line, such as proteins involved in carbohydrate metabolism and plant defense responses (malate dehydrogenase and peroxidase), metabolic process (adenosine kinase), regulating cell redox homeostasis (disulfide isomerase) and lignin biosynthetic process (laccase). Moreover, the expression of pyrroline-5-carboxylate reductase, involved in proline biosynthesis, was significantly changed in both sunflower lines in response to pathogen culture filtrate. Proteins which were only up-regulated in the partially resistant lines might have a significant role in mediating the defense against Sclerotinia and could be considered for enhancing resistance against this devastating pathogen.

5.
Environ Sci Pollut Res Int ; 28(46): 65687-65699, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34322798

ABSTRACT

Two soils contaminated with potentially toxic metals (PTMs) contrasting in pH and mineralogy were remediated with CaEDTA, and changes in soil organic matter (SOM) composition were investigated. Previous studies showed no significant loss of SOM from CaEDTA-treated soils, but the results of our study reflected significant decreases (from 46 to 49%) in the free fraction of humic acids (HAs). Remediation affected the composition of the free HA fraction via disturbance of intermolecular bonds - an increase in phenolic and aromatic groups with a simultaneous decrease in carbohydrates - which was confirmed by FTIR spectroscopy in both soils. Because non-radical molecules such as carbohydrates were selectively removed, the concentration of free radicals in the free HA fraction increased in acidic soil. The bound fraction of HAs and fulvic acids (FAs) in SOM, which are important due to their stability and the permanent effects they have on the soil's physical properties, remained unchanged in both remediated soils. The effect of soil recultivation was observed only in the excitation emission matrix (EEM) fluorescence spectra of HAs. In terms of SOM, CaEDTA soil washing can be considered moderately conservative; however, the restoration of free humic fractions is likely to be a long-term process.


Subject(s)
Soil Pollutants , Soil , Edetic Acid , Humic Substances/analysis , Soil Pollutants/analysis
6.
Front Nutr ; 8: 777214, 2021.
Article in English | MEDLINE | ID: mdl-34977120

ABSTRACT

Helianthus annuus L. seed hull is an abundant waste of the edible oil industry. To envisage potential applications of this waste, here, we aimed to analyze the chemical composition of milled sunflower hulls (SP), constituted mainly by 210 µm (51.4%) and 420 µm (27.6%) average mesh particle sizes. SP contained almost 30% of cellulose, 26.4% of lignin, 38.5% of neutral sugars, mainly hemicelluloses, and only 1.3% of proteins. The important lignin content and low pectin content (4.0% of uronic acids) present in SP were both ascribed to its low hydrophilic behavior and hydration capacity. Phenolic compounds were mostly proanthocyanidins (168 mg/100 g SP), with lower amounts of extractable (31.4 mg/100 g SP) phenolics (O-caffeoylquinic acid), all of them associated with the DPPH radical scavenging capacity (95 mg ascorbic acid equiv./100 g) and ferric reducing power (FRAP: 152 mg ascorbic acid equiv./100 g) shown by SP. Esterified ferulic acid (52.9 mg/100 g SP) was also found, mostly as monomers and trimers. SP of 53 µm particle size was then assayed as a filler (0, 5, 8, and 12% concentrations) in calcium low methoxyl pectin-based films, which showed antioxidant capacity (DPPH and FRAP assays) in an SP-concentration-dependent manner. SP showed homogeneous dispersion in composite films equilibrated at 57.7% relative humidity. Water content decreased while film thickness increased with SP concentration. When loaded at a 12% level, the presence of 53-µm SP decreased the water vapor permeability and increased the normal stress at film fracture. Sunflower hulls can then be applied to the development of active materials like 12% SP film, which can be proposed as a food slice antioxidant separator to be investigated in a future work.

7.
J Mt Sci ; 17(10): 2459-2484, 2020.
Article in English | MEDLINE | ID: mdl-33052199

ABSTRACT

At the end of October 2018, a storm of unprecedented strength severely damaged the forests of the eastern sector of the Italian Alps. The affected forest area covers 42,500 ha. The president of one of the damaged regions asked for help from the University of Padua. After eight months of discussion, the authors of this article wrote a consensus text. The sometimes asper debate brought to light some crucial aspects: 1) even experienced specialists may have various opinions based on scientific knowledge that lead to conflicting proposals for action. For some of them there is evidence that to restore a destroyed natural environment it is more judicious to do nothing; 2) the soil corresponds to a living structure and every ecosystem's management should be based on it; 3) faced with a catastrophe, people and politicians find themselves unarmed, also because they rarely have the scientific background to understand natural processes. Yet politicians are the only persons who make the key decisions that drive the economy in play and therefore determine the near future of our planet. This article is an attempt to respond directly to a governor with a degree in animal production science, who formally and prudently asked a university department called "Land, Environment, Agriculture and Forestry" for help before taking decisions; 4) the authors also propose an artistic interpretation of facts (uncontrolled storm) and conclusions (listen to the soil). Briefly, the authors identify the soil as an indispensable source for the renewal of the destroyed forest, give indications on how to prepare a map of the soils of the damaged region, and suggest to anchor on this soil map a series of silvicultural and soil management actions that will promote the soil conservation and the faster recovery of the natural dynamic stability and resilience. ELECTRONIC SUPPLEMENTARY MATERIAL: Supplementary material is available for this article at 10.1007/s11629-019-5890-0 and is accessible for authorized users.

9.
Environ Toxicol Chem ; 38(12): 2688-2697, 2019 12.
Article in English | MEDLINE | ID: mdl-31499587

ABSTRACT

The ability of the simultaneously extracted metals/acid volatile sulfides (∑SEM/AVS) index to ascertain environmental risk from potentially toxic elements in calcareous saltmarsh soils was tested using structural equation modeling. This technique allows the detection of both direct and indirect relationships among AVS, SEM, and other soil variables, representing results in a graphical view. The dataset included 90 soil samples from 21 different sites belonging to 6 different saltmarshes and featured a wide range of soil chemicophysical properties. Variables included in the a priori model were hydroperiod, pH, soil redox potential, labile organic carbon, carbonates, total iron, and total amount of potentially toxic elements (PTEs). The best optimized model pointed out the main soil properties that affect AVS accumulation and SEM speciation in these soils. Effect plots of AVS and SEM calculated with the partial linear mixed-effects models included in the piecewise structural equation modeling showed a significant and positive influence of pH and carbonates on AVS and a highly significant effect of carbonates and labile organic carbon on SEM. Single SEM components were also considered separately, to define the potential contributions of labile organic carbon or carbonates as alternative binding phases. Simultaneously extracted Cu, Ni, and Zn were preferentially bound to carbonates, followed by labile organic carbon, whereas Pb and Cd were easily bound to labile organic carbon. Environ Toxicol Chem 2019;38:2688-2697. © 2019 SETAC.


Subject(s)
Carbon/chemistry , Carbonates/chemistry , Metals, Heavy/chemistry , Soil Pollutants/chemistry , Soil/chemistry , Environmental Monitoring/methods , Sulfides/chemistry
10.
Front Plant Sci ; 10: 1652, 2019.
Article in English | MEDLINE | ID: mdl-32038669

ABSTRACT

Conversion of conventional farming (CF) to organic farming (OF) is claimed to allow a sustainable management of soil resources, but information on changes induced on dissolved organic matter (DOM) are scarce. Among DOM components, dissolved humic substances (DHS) were shown to possess stimulatory effects on plant growth. DHS were isolated from CF and OF soil leacheates collected from soil monolith columns: first in November (bare soils) and then in April and June (bare and planted soils). DHS caused an enhancement of nitrate uptake rates in maize roots and modulated several genes involved in nitrogen acquisition. The DHS from OF soil exerted a stronger biostimulant action on the nitrate uptake system, but the first assimilatory step of nitrate was mainly activated by DHS derived from CF soil. To validate the physiological response of plants to DHS exposure, real-time RT-PCR analyses were performed on those genes most involved in nitrate acquisition, such as ZmNRT2.1, ZmNRT2.2, ZmMHA2 (coding for two high-affinity nitrate transporters and a PM H+-proton pump), ZmNADH:NR, ZmNADPH:NR, and ZmNiR (coding for nitrate reductases and nitrite reductase). All tested DHS fractions induced the upregulation of nitrate reductase (NR), and in particular the OF2 DHS stimulated the expression of both tested transcripts encoding for two NR isoforms. Characteristics of DHS varied during the experiment in both OF and CF soils: a decrease of high molecular weight fractions in the OF soil, a general increase in the carboxylic groups content, as well as diverse structural modifications in OF vs. CF soils were observed. These changes were accelerated in planted soils. Similarity of chemical properties of DHS with the more easily obtainable water-soluble humic substance extracted from peat (WEHS) and the correspondence of their biostimulant actions confirm the validity of studies which employ WEHS as an easily available source of DHS to investigate biostimulant actions on agricultural crops.

11.
Environ Toxicol Chem ; 37(12): 3025-3031, 2018 12.
Article in English | MEDLINE | ID: mdl-30259571

ABSTRACT

Monitoring of biogenic sulfide is important because acid volatile sulfides (AVS) represent a reactive pool responsible for immobilization of toxic metals. We propose a new sulfide paper sensor method for semiquantitative determination of AVS in which developed color is compared to a reference chart. The method was validated against the ion-selective microelectrode and the purge-and-trap methods. For fieldwork, readings should fall within 1 to 10 µmoles S2- . Considering that the volume of soil used ranged between 1 and 16 cm3 , the corresponding soil sulfides concentration range spans from 0.06 to 10 mmoles S2- cm-3 . The sulfide paper sensor method is highly suitable for field screening and has sensitivity levels comparable to laboratory methods. Environ Toxicol Chem 2018;37:3025-3031. © 2018 SETAC.


Subject(s)
Acids/analysis , Environmental Monitoring/instrumentation , Soil Pollutants/analysis , Soil/chemistry , Sulfides/analysis , Color , Ion-Selective Electrodes , Linear Models , Microelectrodes , Time Factors , Volatilization
12.
Carbohydr Polym ; 164: 13-22, 2017 May 15.
Article in English | MEDLINE | ID: mdl-28325309

ABSTRACT

Considering the polysaccharide composition and 32% of crystallinity of the water insoluble fiber extracted from corn husk (CHF) agricultural residue, its filler performance as water vapor permeability (WVP) and mechanical modifier in edible films based on commercial low methoxyl pectin (LMP) was evaluated (0, 1, 3, 5, 8% concentrations). The 53-µm-CHF carried phenolics and carotenes, and composites showed antioxidant capacity. Homogeneous films with a continuous LMP matrix were obtained. The 5%-CHF composite showed the highest surface contact angle (44°) and tensile strength, without change in elongation, while WVP was decreased in the 3-8% CHF-LMP-films. The latter was ascribed to the CHF-filler crystallinity whereas the improvement in mechanical performance and contact angle was attributed to a CHF-interconnected network formed at 5%-CHF critical concentration. Corn husk residue can be utilized as a source of fibers for material development. Composites with enhanced performance can be an antioxidant strategy at food interfaces.


Subject(s)
Food Packaging , Pectins/chemistry , Tensile Strength , Zea mays , Permeability
13.
Carbohydr Polym ; 136: 1041-51, 2016 Jan 20.
Article in English | MEDLINE | ID: mdl-26572445

ABSTRACT

The effect of particle size (53, 105 and 210 µm) of carrot fiber (CF) on their hydration properties and antioxidant capacity as well as on the performance of the CF-composite films developed with commercial low methoxyl pectin (LMP) was studied. It was determined that CF contained carotenoids and phenolics co-extracted with polysaccharides (80%), rich in pectins (15%). CF showed antioxidant activity and produced homogeneous calcium-LMP-based composites. The 53-µm-CF showed the lowest hydration capability and produced the least elastic and deformable composite film due probably to CF bridged by calcium-crosslinked LMP chains. Antioxidant activity associated to the loaded CF was found in composites. When L-(+)-ascorbic acid (AA) was also loaded, its hydrolytic stability increased with the decrease in CF-particle size, showing the lowest stability in the 0%-CF- and 210 µm-CF-LMP films. Below ≈ 250 µm, the particle size determined the hydration properties of pectin-containing CF, affecting the microstructure and water mobility in composites.


Subject(s)
Antioxidants/chemistry , Ascorbic Acid/chemistry , Carotenoids/chemistry , Cellulose/analogs & derivatives , Daucus carota/chemistry , Plant Extracts/chemistry , Cellulose/chemistry , Drug Packaging/methods , Drug Stability , Elasticity , Hydrolysis , Pectins/chemistry , Tensile Strength
14.
Physiol Plant ; 154(1): 82-94, 2015 May.
Article in English | MEDLINE | ID: mdl-25288471

ABSTRACT

Iron (Fe) sources available for plants in the rhizospheric solution are mainly a mixture of complexes between Fe and organic ligands, including phytosiderophores (PS) and water-extractable humic substances (WEHS). In comparison with the other Fe sources, Fe-WEHS are more efficiently used by plants, and experimental evidences show that Fe translocation contributes to this better response. On the other hand, very little is known on the mechanisms involved in Fe allocation in leaves. In this work, physiological and molecular processes involved in Fe distribution in leaves of Fe-deficient Cucumis sativus supplied with Fe-PS or Fe-WEHS up to 5 days were studied combining different techniques, such as radiochemical experiments, synchrotron micro X-ray fluorescence, real-time reverse transcription polymerase chain reaction and in situ hybridization. In Fe-WEHS-fed plants, Fe was rapidly (1 day) allocated into the leaf veins, and after 5 days, Fe was completely transferred into interveinal cells; moreover, the amount of accumulated Fe was much higher than with Fe-PS. This redistribution in Fe-WEHS plants was associated with an upregulation of genes encoding a ferric(III) -chelate reductase (FRO), a Fe(2+) transporter (IRT1) and a natural resistance-associated macrophage protein (NRAMP). The localization of FRO and IRT1 transcripts next to the midveins, beside that of NRAMP in the interveinal area, may suggest a rapid and efficient response induced by the presence of Fe-WEHS in the extra-radical solution for the allocation in leaves of high amounts of Fe. In conclusion, Fe is more efficiently used when chelated to WEHS than PS and seems to involve Fe distribution and gene regulation of Fe acquisition mechanisms operating in leaves.


Subject(s)
Cucumis sativus/metabolism , Fertilizers , Iron Deficiencies , Plant Leaves/metabolism , Humic Substances , In Situ Hybridization , Iron/administration & dosage , Iron Radioisotopes , Siderophores , Spectrometry, X-Ray Emission , Synchrotrons
15.
Sci Total Environ ; 441: 10-8, 2012 Dec 15.
Article in English | MEDLINE | ID: mdl-23134765

ABSTRACT

The aim of this study was to measure and compare methane oxidation rates of arable and grassland soils that received 7.5t ha⁻¹ y⁻¹ of noncontaminated aerobically treated sewage sludge for ten years. Arable soils showed generally lower methane oxidation rates (from 6 to 15∗10⁻³ h⁻¹) than grassland soils (from 26 to 33∗10³ h⁻¹). Oxidation rate constants (k) of soils amended with sewage sludge were remarkably close to their respective untreated controls, but a soil, that had received a tenfold sewage sludge application (i.e. 75 t ha⁻¹ y⁻¹), showed a statistically significantly higher k-value. Laboratory addition of up to 1000 mg Pb g⁻¹ soil to this soil did not cause any significant change in methane oxidation, but caused a decrease from 13.9 to 10.9×10⁻³ h⁻¹ in the control soil. Addition of Zn was much more toxic than Pb, with a significant decrease at 300 µg g⁻¹ soil rate and an almost complete inhibition at 1500 µg g⁻¹ soil rate. Higher resistance was evident of sewage sludge treated soil in comparison to control soil, for both biomass C and CH4 oxidation activity.


Subject(s)
Bacteria/metabolism , Methane/metabolism , Sewage , Soil Microbiology , Soil Pollutants/metabolism , Bacteria/drug effects , Biomass , Environmental Monitoring , Italy , Lead/metabolism , Lead/toxicity , Oxidation-Reduction , Soil Pollutants/toxicity , Time Factors , Zinc/metabolism , Zinc/toxicity
16.
Biochem Biophys Res Commun ; 367(2): 323-9, 2008 Mar 07.
Article in English | MEDLINE | ID: mdl-18174023

ABSTRACT

The persistence of prions, the causative agents of transmissible spongiform encephalopathies, in soil constitutes an environmental concern and substantial challenge. Experiments and theoretical modeling indicate that a particular class of natural polyanions diffused in soils and waters, generally referred to as humic substances (HSs), can participate in the adsorption of prions in soil in a non-specific way, mostly driven by electrostatic interactions and hydrogen bond networks among humic acid molecules and exposed polar protein residues. Adsorption of HSs on clay surface strongly raises the adsorption capacity vs proteins suggesting new experiments in order to verify if this raises or lowers the prion infectivity.


Subject(s)
Organic Chemicals/chemistry , Prions/chemistry , Soil Pollutants/chemistry , Adsorption , Anions , Binding Sites , Protein Binding , Soil
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