We systematically investigated how the combinations of size, shape and the natural organic matter (NOM)-ecocorona of gold (Au) engineered nanoparticles (ENPs) influence the attachment of the particles to algae and physical toxicity to the cells. Spherical (10, 60 and 100 nm), urchin-shaped (60 nm), rod-shaped (10 × 45, 40 × 60 and 50 × 100 nm), and wire-shaped (75 × 500, 75 × 3000 and 75 × 6000 nm) citrate-coated and NOM-coated Au-ENPs were used. Among the spherical particles only the spherical 10 nm Au-ENPs caused membrane damage to algae. Only the rod-shaped 10 × 45 nm induced membrane damage among the rod-shaped Au-ENPs. Wire-shaped Au-ENPs caused no membrane damage to the algae. NOM ecocorona decreased the membrane damage effects of spherical 10 nm and rod-shaped 10 × 45 nm ENPs. The spherical Au-ENPs were mostly loosely attached to the cells compared to other shapes, whereas the wire-shaped Au-ENPs were mostly strongly attached compared to particles with other shapes. NOM ecocorona determined the strength of Au-ENPs attachment to the cell wall, leading to the formation of loose rather than strong attachment of Au-ENPs to the cells. After removal of the loosely and strongly attached Au-ENPs, some particles remained anchored to the surface of the algae. The highest concentration was detected for spherical 10 nm Au-ENPs followed by rod-shaped 10 × 45 nm Au-ENPs, while the lowest concentration was observed for the wire-shaped Au-ENPs. The combined effect of shape, size, and ecocorona controls the Au-ENPs attachment and physical toxicity to cells.
- MeSH
- buněčná membrána účinky léků ultrastruktura MeSH
- ekotoxikologie MeSH
- huminové látky analýza MeSH
- konfokální mikroskopie MeSH
- kovové nanočástice * chemie toxicita MeSH
- mikrořasy účinky léků růst a vývoj MeSH
- povrchové vlastnosti MeSH
- velikost částic MeSH
- zlato * chemie toxicita MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Environmental friendly agricultural management has an urgent need for finding a sustainable strategy for the usage of different by-products from bioenergy production. These are either used as soil amendments or fertilizers. This study is aimed at evaluating if and how soil organic matter changes after the application of biochar, compost, and digestate. A pot experiment was conducted with Haplic Cambisol (low range arable soil) in Phytotron CLF PlantMaster (Wertingen, Germany). The chemical composition of isolated humic acids (HA) was determined by an inductively coupled plasma-mass spectrometer (ICP-MS). FT-IR spectroscopy and CHNS analysis were used for detailed chemical and optical characterization. Soil magnetic properties - radical concentration, g-parameters of radicals, and iron ions were evaluated by EPR spectroscopy. The results showed that amending arable soil with biochar, digestate and compost results in chemical and structural changes of humic substances. The radicals originated in biochar and digestate are built-in to the structure of the humic acid, which was confirmed by EPR g-parameter values. Despite a relatively high concentration of paramagnetic metal ions Fe and Mn the effect of semiquinone radical quenching was not observed. That suggests a conclusion that metal ions of studied amendments are binding in HA structure and did not disturb natural radical processes in the soil. It was also concluded that the effect of applied material depends mainly on its chemical properties and the soil type.
- MeSH
- huminové látky * analýza MeSH
- průmyslová hnojiva MeSH
- půda * MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Německo MeSH
Sequestration of arsenic to biogenic sulfide minerals is known from As-contaminated anoxic environments. Despite numerous successful laboratory experiments, the process remains difficult to predict in moderate arsenic conditions. We performed microcosm experiments using naturally contaminated groundwater (containing ca. 6 mg/L As) and natural organic matter (NOM) particles both collected from wetland soil. Macroscopic realgar precipitates, occasionally accompanied by bonazziite, a FeS phase, elementary S, calcite, and whewellite, appeared after 4 to 18 months. Realgar only precipitated in microcosms moderately poisoned by azide or antibiotics and those in which oxidation of hydrogen sulfide to sulfur took place. The biomineralization process was not affected by the presence of additional carbon sources or the diversity, community structure, and functional composition of the microbial community. Hydrogen sulfide concentration was greater in the realgar-free microcosms, suggesting that arsenic thiolation prevented precipitation of realgar. We compared our data to available microbial community data from soils with different rates of realgar precipitation, and found that the communities from realgar-encrusted NOM particles usually showed limited sulfate reduction and the presence of fermentative metabolisms, whereas communities from realgar-free NOM particles were strongly dominated by sulfate reducers. We argue that the limited sulfate supply and intensive fermentation amplify reducing conditions, which make arsenic sulfide precipitation plausible in high-sulfate, low-arsenic groundwaters.
- MeSH
- arsenikové přípravky analýza MeSH
- biomineralizace * MeSH
- chemické látky znečišťující vodu analýza MeSH
- huminové látky analýza MeSH
- mikrobiota * MeSH
- mokřady MeSH
- oxidace-redukce MeSH
- podzemní voda chemie mikrobiologie MeSH
- půda chemie MeSH
- sírany chemie MeSH
- sulfidy analýza MeSH
- teoretické modely MeSH
- Publikační typ
- časopisecké články MeSH
The aim of this study was to determine the content, distribution and behaviour of Al in soils under beech forest with different parent rock, and to assess the role of herbaceous vegetation on soil Al behaviour. We hypothesize that the contents of elements in the soil sorption complex (Al etc.) are strongly influenced by vegetation cover. Also, low molecular mass organic acids (LMMOA) can be considered as an indicator of soil organic matter (SOM) decomposition and vegetation litter turnover. Speciation of LMMOA, nutrition content (PO43-, Ca2+, K+) and element composition in aqueous extracts were determined by means of ion chromatography and inductively coupled plasma - optical emission spectrometry (ICP-OES) respectively. Active and exchangeable pH, sorption characteristics and exchangeable Al (Alex) were determined in BaCl2 extracts by ICP-OES. Elemental composition of parent rocks was assessed by means of X-ray fluorescence spectroscopy. Herb-poor localities showed lower pH, less nutrients (PO43-, Ca2+, K+), less LMMOA, a larger stock of SOM and greater cation exchange capacity. There was also lower mobilisation of Al in organic horizons, which explains the larger pools of Al. Generally, we can conclude that LMMOA, and thus soil vegetation cover, play an important role in the Al soil cycle.
- MeSH
- buk (rod) chemie účinky léků růst a vývoj metabolismus MeSH
- chelátory analýza chemie MeSH
- fyzikální absorpce účinky léků MeSH
- fyziologická absorpce účinky léků MeSH
- geologické sedimenty chemie MeSH
- hliník analýza chemie metabolismus toxicita MeSH
- huminové látky analýza MeSH
- koncentrace vodíkových iontů MeSH
- látky znečišťující půdu analýza chemie metabolismus toxicita MeSH
- léčivé rostliny účinky léků růst a vývoj metabolismus MeSH
- lesy MeSH
- molekulová hmotnost MeSH
- půda chemie MeSH
- rostliny účinky léků metabolismus MeSH
- rozpustnost MeSH
- vývoj rostlin účinky léků MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
- Geografické názvy
- Česká republika MeSH
The ability of the DGT technique to predict Hg2+ bioavailability for input tissues (skin, gills, and scales) of common carp in the presence of chloride ions and humic acid (HA) was evaluated. The mercury accumulation by the DGT units and input tissues of carp decreased with an increasing concentration of chloride ions (29-180 mg L-1) and HA (0-5 mg L-1). In the presence of chloride ions and HA, statistically significant correlations (Pearson's correlation coefficients 0.731-0.954) were determined between the rate of mercury accumulation by input tissues of carp and the rate of mercury accumulation by the DGT units. The laboratory experiments suggest the possibility of using the DGT technique for predicting the mercury bioaccumulation in natural aquatic ecosystems instead of commonly used input tissues of fish.
- MeSH
- biologická dostupnost MeSH
- chemické látky znečišťující vodu analýza MeSH
- chloridy analýza MeSH
- ekosystém MeSH
- huminové látky analýza MeSH
- kapři metabolismus MeSH
- kůže chemie MeSH
- metody MeSH
- rtuť analýza farmakokinetika MeSH
- žábry chemie MeSH
- zvířata MeSH
- zvířecí šupiny chemie MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
To assess the environmental fate of engineered nanoparticles (ENPs), it is essential to understand their interactions with dissolved organic matter (DOM). The highly complex nature of the interactions between DOM and ENPs and other particulate matter (PM) requires investigating a wide range of material types under different conditions. However, despite repeated calls for an increased diversity of the DOM and PM studied, researchers increasingly focus on certain subsets of DOM and PM. Considering the discrepancy between the calls for more diversity and the research actually carried out, we hypothesize that materials that were studied more often are more visible in the scientific literature and therefore are more likely to be studied again. To investigate the plausibility of this hypothesis, we developed an agent-based model simulating the material choice in the experiments studying the interaction between DOM and PM between 1990 and 2015. The model reproduces the temporal trends in the choice of materials as well as the main properties of a network that displays the DOM and PM types investigated experimentally. The results, which support the hypothesis of a positive reinforcing material choice, help to explain why calls to increase the diversity of the materials studied are repeatedly made and why recent criticism states that the selection of materials is unbalanced.
- MeSH
- chemické látky znečišťující vodu analýza MeSH
- chemické modely MeSH
- huminové látky analýza MeSH
- monitorování životního prostředí metody MeSH
- nanočástice MeSH
- organické látky analýza MeSH
- pevné částice analýza MeSH
- počítačová simulace MeSH
- rozpustnost MeSH
- výběrový bias * MeSH
- výzkumný projekt MeSH
- zkreslení výsledků (epidemiologie) * MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Indirect impact of humic acid (HA) on metal accumulation and toxicity (Cd, Ni, Pb, and Hg; 100 μM; 24 h of exposure) in Scenedesmus quadricauda was studied. Algae were pre-cultured on solid (10 and 100 mg HA/L) or in liquid media (1, 5, and 10 mg HA/L) over 30 days and then exposed to metals mentioned above. Accumulation of applied metals irrespective of pre-culture increased in the order Ni < Cd < Pb < Hg. Algae pre-cultured on solid HA-enriched media accumulated more Cd (+ 46% at 10 mg HA/L), Ni (+ 50 and + 81% at 10 and 100 mg HA/L, respectively), and Pb (+ 15% at 100 mg HA/L) but the impact on Hg amount was not detected. Potassium and calcium decreased in response to all metals (K strongly under Hg excess) and HA had negligible impact. Interestingly, fluorescence microscopy detection of reactive oxygen species/nitric oxide (ROS/NO) balance showed that HA pre-culture suppressed ROS signal and stimulated NO signal in response to Cd (indicating positive impact of HA) while ROS signal in Ni and Pb treatments rather increased but NO signal decreased as expected from elevated Ni and Pb accumulation. Hg had clearly the most toxic impact on the ROS/NO balance. Algae pre-cultured in liquid HA-enriched media showed significantly increased Ni accumulation only (+ 14% at a dose 10 mg HA/L). Present study for the first time showed that humic acid may indirectly affect accumulation of metals and that solid HA-enriched medium used for pre-culture is more suitable to increase accumulation of metals by algae.
- MeSH
- chemické látky znečišťující vodu toxicita MeSH
- fluorescenční mikroskopie MeSH
- huminové látky analýza MeSH
- mikrořasy účinky léků MeSH
- oxidační stres MeSH
- reaktivní formy kyslíku metabolismus MeSH
- Scenedesmus účinky léků MeSH
- testy akutní toxicity MeSH
- těžké kovy toxicita MeSH
- vztah mezi dávkou a účinkem léčiva MeSH
- Publikační typ
- časopisecké články MeSH
Present-day terrestrial analogue sites are crucial ground truth proxies for studying life in geochemical conditions close to those assumed to be present on early Earth or inferred to exist on other celestial bodies (e.g. Mars, Europa). Although hypersaline sapropels are border-of-life habitats with moderate occurrence, their microbiological and physicochemical characterization lags behind. Here, we study the diversity of life under low water activity by describing the prokaryotic communities from two disparate hypersaline sapropels (Transylvanian Basin, Romania) in relation to geochemical milieu and pore water chemistry, while inferring their role in carbon cycling by matching taxa to known taxon-specific biogeochemical functions. The polyphasic approach combined deep coverage SSU rRNA gene amplicon sequencing and bioinformatics with RT-qPCR and physicochemical investigations. We found that sapropels developed an analogous elemental milieu and harbored prokaryotes affiliated with fifty-nine phyla, among which the most abundant were Proteobacteria, Bacteroidetes and Chloroflexi. Containing thirty-two candidate divisions and possibly undocumented prokaryotic lineages, the hypersaline sapropels were found to accommodate one of the most diverse and novel ecosystems reported to date and may contribute to completing the phylogenetic branching of the tree of life.
- MeSH
- Archaea klasifikace genetika izolace a purifikace MeSH
- Bacteroidetes genetika izolace a purifikace MeSH
- benzopyrany analýza MeSH
- Chloroflexi genetika izolace a purifikace MeSH
- DNA bakterií genetika MeSH
- fylogeneze MeSH
- geologické sedimenty mikrobiologie MeSH
- huminové látky analýza MeSH
- jezera mikrobiologie MeSH
- Proteobacteria genetika izolace a purifikace MeSH
- ribozomální DNA genetika MeSH
- sekvenční analýza DNA MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
- Geografické názvy
- Rumunsko MeSH
Nowadays trace metal contamination of soils represents an important environmental hazard. Nevertheless, the use of some secondary waste products as amendments may restore the common soil functions. This paper focuses on the chemical and biological influence of wood biochar (BC), wood ash (WA) and humic substances (HS), alone and in the mixtures, on a heavily multi-contaminated sandy loam soil. The soil was amended by above-mentioned materials to follow a pH-increasing design (pHCa from 6.0 to 6.5, 7.0 and 7.5); soil samples were analyzed after 3, 30, and 60 days using a set of variables, namely the plant-available trace element concentrations (Cu, Cd, and Zn), microbial biomass carbon (Cmic), and microbial quotient (qCO2), as well as toxicity to Sinapis alba and Daphnia magna. Wood ash and WA + HS were the most efficient treatments to decrease mobile Cd and Zn concentrations in the soil, while HS, BC, and BC + HS combinations were the most effective in reducing the Cu mobility. The effect of BC and WA on the Cmic and qCO2 was mostly negative, whereas adding HS markedly increased Cmic and reduced qCO2 in soil. After amendment applications, the root elongation of mustard was significantly increased in HS and combined treatments (BC + HS, WA + HS). Additionally, BC + HS, WA + HS and WA 8.4% significantly decreased the toxicity of leachates to D. magna to the low-, or non-toxic levels. Our results suggest that the combination of amendments with HS can be a suitable remediation strategy for heavily contaminated soils.
- MeSH
- biomasa MeSH
- dřevěné a živočišné uhlí chemie MeSH
- dřevo chemie MeSH
- huminové látky analýza MeSH
- látky znečišťující půdu analýza MeSH
- půda chemie MeSH
- regenerace a remediace životního prostředí metody MeSH
- stopové prvky analýza MeSH
- uhlík analýza MeSH
- znečištění životního prostředí MeSH
- Publikační typ
- časopisecké články MeSH
Zero-valent iron nanoparticles (nZVI) are a relatively new option for the treatment of contaminated soil and groundwater. However, because of their apparent toxicity, nZVI in high concentrations are known to interfere with many autochthonous microorganisms and, thus, impact their participation in the remediation process. The effect of two commercially available nZVI products, Nanofer 25 (non-stabilized) and Nanofer 25S (stabilized), was examined. Considerable toxicity to the soil yeast Trichosporon cutaneum was observed. Two chemically different humic substances (HSs) were studied as a possible protection agent that mitigates nZVI toxicity: oxidized oxyhumolite X6 and humic acid X3A. The effect of addition of HSs was studied in different phases of the experiment to establish the effect on cells and nZVI. SEM and TEM images revealed an ability of both types of nZVI and HSs to adsorb on surface of the cells. Changes in cell surface properties were also observed by zeta potential measurements. Our results indicate that HSs can act as an electrosteric barrier, which hinders mutual interaction between nZVI and treated cell. Thus, the application of HS seems to be a promising solution to mitigating the toxic action of nZVI.
