EDTA Concentration Research Articles

Investigating the Interactive Effect of Arbuscular Mycorrhizal Fungi and Different Chelating Agents (EDTA and DTPA) with Different Plant Species on Phytoremediation of Contaminated Soil

Heavy metal (HM) contamination in soil poses a severe environmental threat, jeopardizing ecosystem health and potentially entering the food chain through plant uptake. Phytoremediation, a bioremediation technique utilizing plants to remove or immobilize contaminants, offers a sustainable and eco-friendly solution for HM remediation. This study investigated the interactive effects of arbuscular mycorrhizal fungi (AMF) and chelating agents (EDTA and DTPA) on the growth of maize (Zea mays L.) and alfalfa (Medicago sativa L.) cultivated in metal-contaminated soil and their impact on HM uptake by these plants. The findings revealed that AMF and chelating agents have complex interactive effects on plant growth and metal accumulation. Maize (Zea mays L.) shoot dry matter increased with AMF and chelating agents at lower concentrations. Both plants generally showed a significant (p ≤ 0.05) increase in shoot dry matter with amendments, with AMF × EDTA (10 mmol/kg) being the most effective for alfalfa. DTPA and EDTA generally reduced the DTPA-extractable metals in soil, suggesting potential for metal removal. However, the effects of AMF on metal availability were variable. Metal concentrations in maize (Zea mays L.) shoots increased with increasing DTPA and EDTA concentrations, while the effects of AMF were more complex. The alfalfa shoot metal content showed varied responses, with EDTA (5 mmol/kg) effectively reducing the metal uptake. In general, treatments involving chelating agents (DTPA and EDTA) tend to result in higher bioaccumulation factor (BF) values compared to the non-treated controls for most HMs in both plant species. Mycorrhizal fungi (AMF) treatment alone or in combination with chelating agents also showed that varied effects on HM uptake in both the alfalfa and maize treatments with chelating agents, especially at higher concentrations, generally promoted the greater translocation of HMs in both plant species. Both alfalfa and maize responded differently to treatments, with some treatments showing higher translocation factor (TF) values for certain HMs in one species compared to the other. Mycorrhizal fungi (AMF) treatment alone or in combination with chelating agents also showed varied effects on HM uptake and translocation in both alfalfa and maize. Further research is required to optimize remediation strategies that balance plant health and metal mobilization.

An Interdisciplinary Assessment of the Impact of Emerging Contaminants on Groundwater from Wastewater Containing Disodium EDTA

In recent years, there has been a surge in interest concerning emerging contaminants, also known as contaminants of emerging concern (CECs), due to their presence in environmental matrices. Despite lacking regulation, these chemicals pose potential health and environmental safety risks. Disodium EDTA, a widely utilized chelating agent, has raised concerns regarding its environmental impact. The present work aimed to verify the presence of Disodium EDTA at the exit of eight wastewater treatment plants discharging into some losing streams flowing within a large alluvial aquifer. Conducted in the Province of Parma (Northern Italy), the research employs a multidisciplinary approach, incorporating geological, hydrogeological, chemical, and microbial community analyses. Following a territorial analysis to assess industries in the region, through the use of ATECO codes (a classification system for economic activities), the study investigated the concentration of Disodium EDTA in effluents from eight diverse wastewater treatment plants, noting that all discharges originate from an activated sludge treatment plant, released into surface water courses feeding the alluvial aquifer. Results revealed detectable levels of Disodium EDTA in all samples, indicating its persistence post-treatment. Concentrations ranged from 80 to 980 µg/L, highlighting the need for further research on its environmental fate and potential mitigation strategies. Additionally, the microbial communities naturally occurring in shallow groundwater were analyzed from a hydrogeological perspective. The widespread presence of a bacterial community predominantly composed of aerobic bacteria further confirmed that the studied aquifer is diffusely unconfined or semi-confined and/or diffusely fed by surface water sources. Furthermore, the presence of fecal bacteria served as a marker of diffuse leakage from sewage networks, which contain pre-treated wastewater. Although concentrations of Disodium EDTA above the instrumental quantification limit have not been found in groundwater to date, this research highlights the significant vulnerability of aquifers to Disodium EDTA. It reveals the critical link between surface waters, which receive treated wastewaters impacted by Disodium EDTA, and groundwater, emphasizing how this connection can expose aquifers to potential contamination. At this stage of the research, dilution of wastewaters in surface- and groundwater, as well as hydrodynamic dispersion within the alluvial aquifer, seem to be the main factors influencing the decrease in Disodium EDTA concentration in the subsurface below the actual quantification limit. Consequently, there is a pressing need to enhance methodologies to lower the instrumental quantification limit within aqueous matrices. In a broader context, urgent measures are needed to address the risk of diffuse transport of CECs contaminants like Disodium EDTA and safeguard the integrity of surface and groundwater resources, which are essential for sustaining ecosystems and human health.

Enhancing cadmium phytoremediation in contaminated soil using sunflower (Helianthus annuus L.) with EDTA and vermicompost amendments

The study hypothesis posits that EDTA, an effective chelating agent, can effectively mobilize cadmium from soil, augmenting the sunflower's natural ability to absorb and sequester heavy metals. Concurrently, vermicompost, rich in organic matter and beneficial microorganisms, enhances soil health and supports plant growth, thereby fortifying the sunflower's phytoremediative potential. The pot experiment was carried out as an overall completely randomized design (CRD) at the Sheila Dhar Institute (SDI) experimental farm, University of Allahabad, Prayagraj, in the Kharif season during the years 2023-2024. Plants were cultivated in pots with soil (5 kg) that contained varying concentrations of Cd (0, 15, 30, and 50 mg/kg), vermicompost (0 and 10 g/kg), and EDTA (0 and 2.5 mmol/kg). Plants were also cultivated in containers with clean soil (T1) as control treatment. For analyzed heavy metal (Cd) in plants with a tri-acid mixture (15 ml) containing concentrations of HNO3, H2SO4, and HClO4 in 5:1:2 ratios, use the Atomic Absorption Spectrophotometer (AAS). The result showed that the combined Treatment (T3) pot of application of Cd 0+ EDTA (2.5 mmol/kg) and vermicompost (10 g/kg) was the maximum dry biomass (14.43 g/pot) of the sunflower plant. While the maximum dose combined treatment (T12) application of Cd 50 mg/kg+ EDTA 2.5 mmol/kg and vermicompost 10 g/kg is greater than before, the maximum accumulation of Cd in the shoot and root of Helianthus annuus L. by shoot 37.16% and root 31.16%, respectively as compared to the control treatment pot Cd-50. The results indicate that the combined application of EDTA and vermicompost significantly increased cadmium uptake by sunflowers compared to untreated controls, demonstrating their synergistic effect in improving phytoremediation efficiency.

An artificial intelligence handheld sensor for direct reading of nickel ion and ethylenediaminetetraacetic acid in food samples using ratiometric fluorescence cellulose paper microfluidic chip

User-friendly in-field sensing protocol is crucial for the effective tracing of intended analytes under less-developed countries or resources-limited environments. Nevertheless, existing sensing strategies require professional technicians and expensive laboratory-based instrumentations, which are not capable for point-of-care on-site analyses. To address this issue, artificial intelligence handheld sensor has been designed for direct reading of Ni2+ and EDTA in food samples. The sensing platform incorporates smartphone with machine learning-driven application, 3D-printed handheld device, and cellulose paper microfluidic chip stained with ratiometric red-green-emission carbon dots (CDs). Intriguingly, Ni2+ introduction makes green fluorescent (FL) of CDs glow but red FL fade because of the coordination of Ni2+ with CDs verified by density functional theory (DFT), concurrently manifesting continuous FL colour transition from red to green. Subsequent addition of EDTA renders FL of CDs-Ni2+ recover owing to the capture of Ni2+ from CDs by EDTA based on strong chelation effect of EDTA on Ni2+ confirmed via DFT, accompanying with a noticeable colour returning from green to red. Inspired by above FL phenomena, CDs-based cellulose paper microfluidic chips are first fabricated to facilitate point-of-care testing of Ni2+ and EDTA. Designed fully-automatic handheld sensor is utilized to directly output Ni2+ and EDTA concentration in water, milk, spinach, bread, and shampoo based on wide linear ranges of 0–48 μM and 0–96 μM, and low limits of detection of 0.274 μM and 0.624 μM, respectively. The proposed protocol allows for speedy straightforward on-site determination of target analytes, which will trigger the development of automated and intelligent sensors in near future.

Uptake of Cm (III) and Eu (III) by C–S–H phases under saline conditions in presence of EDTA: A batch sorption and TRLFS study

Eu (III) and Cm (III) uptake by calcium silicate hydrate phases (C–S–H) was investigated in presence of EDTA in NaCl and CaCl2 solutions. Different experimental parameters, i.e., ionic strength (0.1 m ≤ I'm ≤ 5.05 m), ligand concentration (10−5 m ≤ [EDTA] ≤ 10−2 m), calcium-to-silicon ratio (0.6 ≤ C/S ≤ 1.3) and sorption time (7 d ≤ t ≤ 365 d) were varied in the frame of batch sorption experiments and Time Resolved Laser Fluorescence spectroscopy (TRLFS) measurements. No effect of EDTA on the retention of Eu(III)/Cm(III) by C–S–H phases in NaCl or CaCl2 systems was observed at ligand concentrations ≤ 10−3 M. In NaCl solutions with [EDTA] = 10−2 M and C/S < 1.3, low retention (log Rd = 2–3, with Rd in L∙kg−1) of Eu(III) was detected after 7 d of sorption time, while strong retention (log Rd = 5–6) was observed after 50 d. This behaviour was explained by the initial stabilization of Eu(III)/Cm(III) in the aqueous phase due to the formation of two aqueous Eu(III)/Cm(III)-(OH)n-EDTA complexes, followed by the slow incorporation of Eu(III)/Cm(III) into the C–S–H structure. In CaCl2 solutions for all C/S ratios, as well as in NaCl solutions for C/S ∼ 1.3, the presence of [EDTA] = 10−2 M led to a significant decrease of the uptake (log Rd = 2–3) after 7 and 50 d of contact time. This effect was explained by the formation of stable aqueous Ca–Eu(III)/Cm(III)-EDTA complexes triggered by the presence of moderate to high Ca concentrations. No evident effect caused by increased ionic strength conditions could be confirmed in our sorption experiments.Results obtained in batch sorption experiments are underpinned by TRLFS data, with the observation of three main aqueous species, tentatively defined as Cm(OH)(EDTA)2-, Cm(OH)x (EDTA)-(x+1) and Ca–Cm(III)-EDTA, as well as a fourth species corresponding to Cm(III) incorporated in the CaO-layer of the C–S–H phases. In spite of the thermodynamic stability of the CaEDTA2− complex, which reduces the concentration of free EDTA, the formation of ternary Ca–Eu(III)/Cm(III)-EDTA complexes is expected to result in a significant impact of EDTA on the uptake of An (III)/Ln (III) by cement at high ligand concentrations. The assumption that Ca outcompetes actinides for the complexation with EDTA in cementitious systems may need to be revisited under these conditions.

Development of an HSV-1 production process involving serum-reduced culturing and bead-to-bead transfer

Herpes simplex virus type 1 (HSV-1) plays an important role in the field of gene therapy and viral vaccines, especially as an oncolytic virus. However, the mass production of HSV-1 viral vectors remains a challenge in the industry. In this study, a microcarrier-mediated serum-reduced medium culture was used to improve the bioprocess of HSV-1 production and increase HSV-1 yields. The composition of the culture media, which included a basal medium, serum concentration, and glutamine additive, was optimized. The process was successfully conducted in a 1 L bioreactor, and virus production was threefold greater than that of conventional processes with a 10% serum medium. The bead-to-bead transfer process was also developed to further increase scalability. In spinner flasks, the detachment rate increased from 49.4 to 80.6% when combined agitation was performed during digestion; the overall recovery proportion increased from 37.9 to 71.1% after the operational steps were optimized. Specifically, microcarrier loss was reduced during aspiration and transfer, and microcarriers and detached cells were separated with filters. Comparable cell growth was achieved with the baseline process using 2D culture as the inoculum by exchanging the subculture medium. To increase virus production after bead-to-bead transfer, critical parameters, including shear stress during digestion, TrypLE and EDTA concentrations in the subculture, and the CCI, were identified from 47 parameters via correlation analysis and principal component analysis. The optimized bead-to-bead transfer process achieved an average of 90.4% overall recovery and comparable virus production compared to that of the baseline process. This study is the first to report the optimization of HSV-1 production in Vero cells cultured on microcarriers in serum-reduced medium after bead-to-bead transfer.Key points• An HSV-1 production process was developed that involves culturing in serum-reduced medium, and this process achieved threefold greater virus production than that of traditional processes.• An indirect bead-to-bead transfer process was developed with over 90% recovery yield in bioreactors.• HSV-1 production after bead-to-bead transfer was optimized and was comparable to that achieved with 2D culture as inoculum.

Green-emitting carbon quantum dots as efficient fluorescent probes for Cu2+ and EDTA detection by “turn-on-off” strategy

Copper is essential for human body because it plays an important role in various physiological processes, so the sensitive detection of Cu2+ ions is a vital topic in human health and environment safe. In this work, green-emitting carbon quantum dots (CQDs) facilely synthesized by a microwave-assisted hydrothermal method were used as fluorescent probes for Cu2+ detection. The CQDs showed a rapid and sensitive response to Cu2+ with a color change and brightened fluorescence. The fluorescence enhancement of CQDs reaches 4.51-fold by 5 μM Cu2+ as a typical “turn-on” strategy. A good linear relation of the fluorescence enhancement by Cu2+ appears in a range of 0.1–1 μM Cu2+ with a limit of detection (LOD) of 2.46 nM. Then, the enhanced fluorescence of Cu2+-CQDs could be rapidly decreased by EDTA via a quenching response (“turn-off”). A linear range of the fluorescence decrease and EDTA concentration is 1–10 μM with a LOD of 0.19 μM. The interference experiments for the detections of both Cu2+ and EDTA show a high selectivity. The practical detections of both Cu2+ and EDTA in actual water samples and spiked samples demonstrated good reproducibility and effective recovery rates. In addition, the Cu2+-CQDs even had a slow “turn-off” response to histidine over 20 natural amino acids. Overall, the CQDs-based “turn-on-off” detection methods with high sensitivity and selectivity in this work can be considered a promising new choice for the fluorescence analysis of Cu2+ and EDTA.

Enhanced heavy metal leaching from volcanic muds: Synergistic effects of citric acid and EDTA composite system

The soil leaching technology is a well-established technique commonly employed for the remediation of soils contaminated with heavy metals. Volcanic muds share similar properties to those of soil. This study utilizes soil leaching technology to tackle the presence of heavy metals in volcanic muds. It examines the leaching removal effect of the synergistic system of organic acid citric acid (CA) and chelating agent EDTA on heavy metals Pb, Cd, Cr, and Ni in volcanic muds. The leaching conditions were initially selected and subsequently optimized through the application of response surface methodology (RSM). The priority of leaching conditions can be ranked as follows: leaching duration is found to be more crucial than leaching agent concentration, which is noted to be more pivotal than the solid-liquid ratio. Following an in-depth evaluation of model predictions and experimental validation, it has been established that the optimal leaching concentration of EDTA is 0.15 mol·L−1, the optimal leaching duration is 9 h, and the optimal solid-liquid ratio is 1:10. For the compound CA, the most effective leaching concentration is 0.3 mol·L−1, the optimal leaching duration is 8 h, and the optimal ratio of solid to liquid is 1:10. The significance of the leaching conditions was further explored in conjunction with RSM. Furthermore, the integration of both leaching methods, namely combined leaching and stepwise leaching, has been demonstrated to amplify the removal efficiency of heavy metals, with stepwise leaching showing the highest removal rate. The experimental findings suggest that the leaching technique involving CA and EDTA composite system is an effective approach for the remediation of heavy metals such as Pb, Cd, Cr, and Ni in volcanic muds. This study provides theoretical rationale for the adoption of soil leaching technology in the remediation of heavy metals in volcanic muds. Additionally, the heavy metal content of the remediated volcanic muds substantially meets with the standards for cosmetic raw materials.

Extended ADM1 model to study trace metal speciation and its effects on anaerobic digestion

Trace metals (TM) are often added to anaerobic digestors (AD) to improve digestor performance and methane yield. Though numerous experimental studies are done to study TM effects, a model based on ADM1 will help plant operators in case of metal deprivation as there are analytical limitations in quantifying metal speciation which controls TM effects on AD. This study developed a complete dynamic model based on ADM1 with least and unavoidable model input information to study TM speciation and its influence on AD. In addition to the biochemical and gas stripping processes described in ADM1, the model introduced new physicochemical processes with effects of operational conditions like pH, temperature and ionic strength. The biogeochemical processes influencing TM speciation include microbial uptake, precipitation (sulphides, phosphates, carbonates), adsorption (onto biomass, soluble inerts and precipitates), inorganic complexation and organic complexation (with EDTA, VFAs, amino acids (AAs)). The model was tested under different scenarios: variable EDTA concentration and dosing form, variable substrate and variable ionic strength. Complexation of TMs with EDTA and AAs influences metal bioavailability and methane yield. Supplementing EDTA reduces TM dosing and dosing EDTA as metal-EDTA complex is more effective than supplementing metals and EDTA separately. TM-AA complexation depends on substrates as amino acid compounds vary with substrates. Ionic strength influences TM adsorption and precipitation processes and hence is an important operational parameter controlling the system like pH and temperature. The model has been compared to experimental data obtained from this study and has been successfully applied to predict cobalt deprivation in an anaerobic digestor.

Biosorption of Zn by dried biomass of Euglena gracilis from aqueous solutions

The aim of this work was to evaluate the possibility to utilize the dried biomass of Euglena gracilis var. bacillaris as a biosorbent applied for the removal of Zn from aqueous solutions. For these purposes, experiments involving solutions spiked by 65ZnCl2 were carried out under the conditions of batch systems. The prepared biosorbent in the form of dried biomass of E. gracilis (&lt; 300 μm) was characterized in terms of the presence of functional groups (COOH, PO3H2, OH, and NH2), the concentration of binding sites cAn and the value of pHzpc = 6.6 using the modelling program ProtoFit. From the kinetics of Zn biosorption, it can be assumed that the Zn removal was a rapid process, in which the concentration equilibrium [Zn]solution : [Zn]biosorbent was stabilized in the first 5 min of interaction. In individual experiments, the effect of solution pH, initial biosorbent or Zn concentration were evaluated. Based on the MINEQL+ speciation modelling program, we predicted the decrease in the abundance of free Zn2+ cations in the presence of different concentrations of EDTA as a complexing agent in the solution. It was found that the Zn biosorption decreased linearly with the decreasing the proportion of Zn2+ in solution. The biosorption data expressed as equilibrium values of the remaining Zn concentration in solution Ceq (µmol.dm-3) and equilibrium values of specific adsorption Qeq (µmol.g-1; d.w.) were well fitted to the Langmuir model of adsorption isotherm in comparison with the Freundlich model. The maximum adsorption capacity of the dried biomass of E. gracilis for the biosorption of Zn reached the value Qmax = 0.53 ± 0.05 mmol.g-1or 34.7 ± 3.4 mg.g-1 (d.w.), respectively.

Determination of Zinc and Magnesium in Food Samples via Cloud Point Extraction using Brilliant Green as a Reagent

In this article, we present a sensitive and efficient method for the separation and determination of Zinc (II) and Magnesium (II) ions using a combination of liquid ion exchange and cloud point extraction (CPE). The process includes converting these ions into metal ion complexes by using EDTA at pH 10. These complexes are then bound electrostatically with Brilliant Green (BG) to form ion pair association complexes, which are subsequently transferred into a cloud point layer. The study involved optimizing the extraction conditions, including the EDTA concentration, temperature, heating duration, and surfactant volume. The concentration of EDTA for achieving higher extraction efficiency is 1×10-4 M in the presence of 100 μg of Zn(II) and Mg(II) per 10 mL of aqueous solution using 1×10-4 M of BG. The solutions should be heated at 85°C for Zn(II) and 80°C for Mg(II) for 20 minutes. The optimal volume of surfactants is 0.5 mL of Triton X-100 for Zn(II) and 0.6 mL for Mg(II). The study also includes an analysis of the impact of electrolytes and interferences and the spectrophotometric identification of Zn(II) and Mg(II) in various samples.

Controlling Diameter and Morphology of Colloidal-Silica-Abrasives Via Designing Surfactant Functional Group

As the design rule of logic semiconductor has been scaled down toward 5, 3, 2.1, 1.5, and 1.0 nm, the line width of Cu-film as interconnect line of logic semiconductor has been rapidly scaled down toward 36, 32, 24, 20 and 16 nm. The CMP of the Cu-lines is essential fabrication process, challenging an achievement of dishing and erosion during Cu-film CMP. In particular, the dishing and erosion of the Cu-film CMP has been principally affected by the diameter and morphology of colloidal-silica-abrasives in a CMP slurry. In a conventional synthesis method synthesis of colloidal-silica-abrasives, ethoxysilanol was formed via the hydrolysis reaction by Tetraethyl orthosilicate(TEOS) and H2O producing ethoxysilanol, following the condensation reaction between two ethoxysilanol. The diameter of colloidal-silica-abrasives could be obtained by adjusting the concentrations of TEOS, alcohol, and alkali catalyst, but the solid loading of colloidal-silica-abrasives could be varied. Thus, in our study, a novel synthesis method of the colloidal-silica-abrasives was designed by adding a charged functional group surfactant during the conventional colloidal-silica-abrasives synthesis method. The effect of the surfactant having negative charged carboxyl functional group (i.e. Ethylenediaminetetraacetic acid: EDTA) on the diameter and morphology of the colloidal-silica-abrasives were investigated as function of the EDTA concentration; i.e. when the concentration of EDTA increased from 0 to 0.03 wt%, the diameter of colloidal-silica-abrasives increased from 47.0 to 103.8 nm and the solid loading of colloidal-silica-abrasives increased from 2.0 to 2.36 wt%, as shown in Fig. 1. In addition, when the ETDA concentration increased above 0.0025 wt%, the morphology of colloidal-silica-abrasives was transformed from cocoon shape to spherical shape. Furthermore, the effect of the surfactant having the positive charged amine functional group (i.e. Triethanolamine: Tri-ETA, Ethylenediamine: EDA, Diethylenetriamine: DETA, Triethylenetetramine: TETA) were estimated as function of the number of amine functional group in the surfactant, as shown in Fig. 2. When the number of positive charged amine functional groups increased 0 to 4, the diameter of colloidal-silica-abrasives increased from 67.2 to 143.86 nm and the solid loading of colloidal-silica-abrasives increased from 2.0 to 2.2 wt%. In addition, the synthesis with positive charged amine functional group was transformed from cocoon shape to spherical shape. The synthesis mechanism, the enhanced polishing rate of Cu-film surface, dishing and erosion after Cu-film will be presented in detail. Acknowledgement This research was supported by the MOTIE(Ministry of Trade, Industry & Energy (1415180388) and KSRC(Korea Semiconductor Research Consortium) (20019474) support program for the development of the future semiconductor device. Figure 1

Structural characterization of the human DjC20/HscB cochaperone in solution

J-domain proteins (JDPs) form a very large molecular chaperone family involved in proteostasis processes, such as protein folding, trafficking through membranes and degradation/disaggregation. JDPs are Hsp70 co-chaperones capable of stimulating ATPase activity as well as selecting and presenting client proteins to Hsp70. In mitochondria, human DjC20/HscB (a type III JDP that possesses only the conserved J-domain in some region of the protein) is involved in [FeS] protein biogenesis and assists human mitochondrial Hsp70 (HSPA9). Human DjC20 possesses a zinc-finger domain in its N-terminus, which closely contacts the J-domain and appears to be essential for its function. Here, we investigated the hDjC20 structure in solution as well as the importance of Zn+2 for its stability. The recombinant hDjC20 was pure, folded and capable of stimulating HSPA9 ATPase activity. It behaved as a slightly elongated monomer, as attested by small-angle X-ray scattering and SEC-MALS. The presence of Zn2+ in the hDjC20 samples was verified, a stoichiometry of 1:1 was observed, and its removal by high concentrations of EDTA and DTPA was unfeasible. However, thermal and chemical denaturation in the presence of EDTA led to a reduction in protein stability, suggesting a synergistic action between the chelating agent and denaturators that facilitate protein unfolding depending on metal removal. These data suggest that the affinity of Zn+2 for the protein is very high, evidencing its importance for the hDjC20 structure.

Four Decades of the Comet Assay: pH Optimum of Lysis Buffer Still Needs to be Elucidated.

The proper course and reproducibility of diagnostic techniques depend on narrowly defined reaction conditions, including the reaction pH. Nevertheless, numerous assays are affected by an inaccurately defined reaction pH. Buffers are sometimes suggested for use outside their useful pH ranges, which complicates the reproducibility of results because the buffering capacity is insufficient to retain the disclosed pH. Here, we focus on the comet assay lysis buffer. Comet assay is broadly used for quantifying DNA breaks in eukaryotic cells. The most widespread comet assay protocols employ lysis of the cells before electrophoresis in a buffer containing Triton X-100, a high concentration of NaCl, sodium sarcosinate, EDTA, and Tris, with some modifications. However, nearly all researchers report that they use Tris buffer at pH 10, and some report the pH of the Tris additive alone. Alternatively, others report the pH of the final lysis buffer. However, the lysis solution used in the comet assay is buffered at a pH outside the useful range of Tris. Tris-based buffers have a useful pH range of 7.0 - 9.0. The buffer composed of 10 mM Tris has pKa 8.10 at 25°C and 8.69 at 4°C. The cell lysis conditions used in nearly all modifications of comet assay protocols remain imprecise and uncritically employed. Despite the pH of the lysis buffer likely has negligible effect on the detection of DNA breaks, precise lysis conditions are highly important for the use of comet assay in the detection of base modifications, which are often unstable and sensitive to pH.

Evaluation of ethanol and EDTA concentrations in the expression of biofilm-producing smf-1, rpfF genes in XDR clinical isolates of Stenotrophomonas maltophilia

BackgroundStenotrophomonas maltophilia is able to cause infections in immunocompromised patients, and the treatment of this opportunistic pathogen is complicated due to its virulence factors, antibiotic resistance, and the ability of the bacteria to produce biofilm. The main goals of this study were to assess the susceptibility of extensively drug-resistant (XDR) isolates to ethanol and EDTA, and evaluating the synergistic effect of these disinfectants, and also survey the effect of exposure to sub-inhibitory concentrations of ethanol and EDTA on the expression of biofilm-producing smf-1, rpfF genes.ResultsThe results showed that EDTA significantly increased the effectiveness of the ethanol and have a synergistic effect. All of the 10 XDR isolates included in the current study harbored smf-1 and rpfF genes and produced biofilm. After exposure to MIC, sub-MIC, synergism, and sub-synergism of ethanol and EDTA, the expression of smf-1 and rpfF genes was repressed significantly.ConclusionIn the current study, it was indicated that the expression of biofilm-producing genes was repressed when bacteria are exposed to different concentrations of ethanol and EDTA. Future studies should include more complex microbial communities residing in the hospitals, and more disinfectants use in hospitals. Expression of other virulence genes in different conditions is suggested.

Separation of heavy (dysprosium) and light (praseodymium, neodymium) rare earth elements using electrodialysis

This work reports electrodialysis studied to separate dysprosium (Dy, a heavy rare earth element (REE)) from praseodymium and neodymium (Pr, Nd, a mixture of light REEs). A unique electrodialysis setup comprising a cation exchange membrane, a PC-400D membrane (anion exchange membrane that transfers large organic anions), and an anion exchange membrane is used. To achieve the separation of these REEs, ethylenediaminetetraacetic acid disodium salt dihydrate is used as the chelating agent. Because of the higher stability constant of EDTA with Dy(III) compared with Pr(III) and Nd(III), most of EDTA form [Dy-EDTA]− chelate which upon applying electric potential move from the feed to the concentrate compartment through the PC-400D membrane, leaving behind free Pr and Nd cations in the feed compartment. The effect of rinse solution concentration (sodium sulfate, 0.05–0.07 mol/L), applied electric potential (10–14 V), feed pH (2–5), and EDTA concentration (EDTA/Dy molar ratio of 0.9–1.2) on key performance indicators of electrodialysis, i.e., purity, yield, separation factor, and Dy removal efficiency is investigated. Rinse solution concentration has a negligible effect on the separation performance in the studied range. Applied potential shows a positive effect on the Dy removal efficiency, but separation factor decreases with increasing potential above 12 V. The suitable pH range for maximum separation performance is found to be above 3 and below 5. Increasing EDTA/Dy molar ratio increases the amount of Pr and Nd chelates with EDTA, which also move to the concentrate compartment and decrease the product purity. The ratio 1:1 is found to result in the highest Dy purity and separation factor. The rinse solution concentration of 0.05 mol/L with 12 V applied potential, pH 4, and EDTA/Dy molar ratio of 1.0 result in a separation factor of 125 which is promising. Under this set of conditions, a Dy purity of 93% and Dy yield of 77% is achieved.

Acetaminophen and trimethoprim batch and fixed-bed sorption on MgO/Al2O3-modified rice husk biochar

Pharmaceuticals’ ubiquitous presence in surface and groundwater from their increased consumption and inefficient conventional wastewater treatment removal, poses a threat to flora and fauna. Pyrolyzed co-precipitated Mg/Al oxides (3:1) on rice husk biochar surfaces (MgO/Al2O3-BC700) were prepared to treat aqueous acetaminophen and trimethoprim contamination. This adsorbent, characterized for proximate and elemental compositions, crystallinity, surface area, morphology, zero-point charge and functional groups, had a higher surface area (419 m2/g) and pore volume (0.132 cm3/g) than its pristine biochar BC700 analog (surface area 182 m2/g and pore volume 0.062 cm3/g). Hybrid multiphase MgO/Al2O3-BC700 easily adsorbed aqueous acetaminophen and trimethoprim (∼8 h equilibrium) with capacities of 69.7–137.4 mg/g and 54.2–269 mg/g, respectively. It has excellent sorption efficiency at significant ionic strengths (10–50 mM KCl), with competing individual anions (Cl−, CO32−, HCO3−, SO42−) and cations (Ca2+, Na+, Mg2+, Al3+) and with anionic mixtures and cationic mixtures at 0.1, 1.0 and 10 mM concentrations. Column studies for both pharmaceuticals were conducted, and key sorption parameters (EBCT, column capacity, adsorbent use rate, and % saturation) were calculated. Spent MgO/Al2O3-BC700 was regenerated using optimized concentrations of EDTA, HCl, H2SO4, ethanol, and methanol. Regeneration was performed after 3-consecutive adsorption-desorption cycles. Thorough characterization and spectroscopic investigations suggested potential sorption interactions.

Electrochemical analysis of copper-EDTA-ammonia-gold thiosulfate dissolution system

Abstract Ethylenediaminetetraacetic acid disodium (EDTA) can form stable complexes with many metals. To improve the leaching rate of gold and the consumption rate of thiosulfate, EDTA and ammonia were combined with copper ions to form a copper-EDTA-ammonia-thiosulfate system. Electrochemical methods were used to study the effect of thiosulfate, copper ion, EDTA, and polarization voltage. The results showed that increasing the concentrations of thiosulfate, copper ions, and EDTA promoted the dissolution of gold, which changed from electrochemical control to diffusion control after adding EDTA. The order of influence was thiosulfate &gt; EDTA &gt; copper ion. The pure gold leaching experiment showed that the dissolution rate of gold in the EDTA-ammonium-copper thiosulfate system was higher than that in the EDTA-copper-thiosulfuric acid system, thus achieving synergistic gold leaching.

Effect of different levels of EDTA on phytoextraction of heavy metal and growth of Brassica juncea L.

Heavy metal pollution of soil is a major concern due to its non-biodegradable nature, bioaccumulation, and persistence in the environment. To explore the probable function of EDTA in ameliorating heavy metal toxicity and achieve the sustainable development goal (SDG), Brassica juncea L. seedlings were treated with different concentrations of EDTA (0, 1.0, 2.0, 3.0, and 4.0 mM Kg-1) in heavy metal-polluted soil. Plant samples were collected 60 days after sowing; photosynthetic pigments, H2O2, monoaldehyde (MDA), antioxidant enzymes, and ascorbic acid content, as well as plant biomass, were estimated in plants. Soil and plant samples were also examined for the concentrations of Cd, Cr, Pb, and Hg. Moreover, values of the phytoremediation factor were utilized to assess the accumulation capacity of heavy metals by B. juncea under EDTA treatments. In the absence of EDTA, B. juncea seedlings accrued heavy metals in their roots and shoots in a concentration-dependent manner. However, the highest biomass of plants (roots and shoots) was recorded with the application of 2 mM kg-1 EDTA. Moreover, high levels (above 3 mM kg-1) of EDTA concentration have reduced the biomass of plants (roots and shoots), photosynthetic area, and chlorophyll content. The effect of EDTA levels on photosynthetic pigments (chlorophyll a and b) revealed that with an increment in EDTA concentration, accumulation of heavy metals was also increased in the plant, subsequently decreasing the chlorophyll a and b concentration in the plant. TLF was found to be in the order Pb> Hg> Zn> and >Ni, while TF was found to be in the order Hg>Zn>Ni>Pb, and the best dose was 3 mM kg-1 EDTA for Hg and 4 mM kg-1 for Pb, Ni, and Zn. Furthermore, hyperaccumulation of heavy metals enhanced the generation of hydrogen peroxide (H2O2), superoxide anions (O2•-), and lipid peroxidation. It also interrupts mechanisms of the antioxidant defense system. Furthermore, heavy metal stress reduced plant growth, biomass, and chlorophyll (chl) content. These findings suggest that the exogenous addition of EDTA to the heavy metal-treated seedlings increases the bioavailability of heavy metals for phytoextraction and decreases heavy metal-induced oxidative injuries by restricting heavy metal uptake and components of their antioxidant defense systems.

Mesoporous Silica Particle as an RNA Adsorbent for Facile Purification of In Vitro-Transcribed RNA.

Messenger RNA vaccines against SARS-CoV-2 hold great promise for the treatment of a wide range of diseases by using mRNA as a tool for generating vaccination antigens as well as therapeutic proteins in vivo. Increasing interest in mRNA preparation warrants reliable methods for in vitro transcription (IVT) of mRNA, which must entail the elimination of surplus side products such as immunogenic double-stranded RNA (dsRNA). We developed a facile method for the removal of dsRNA from in vitro transcribed RNA with mesoporous silica particles as RNA adsorbents. Various polyamines were tested for the facilitation of RNA adsorption onto mesoporous silica particles in the chromatography. Among the polyamines tested for RNA adsorption, spermidine showed a superior capability of RNA binding to the silica matrix. Mesoporous silica-adsorbed RNA was readily desorbed with elution buffer containing either salt, EDTA, or urea, possibly by disrupting electrostatic interaction and hydrogen bonding between RNA and the silica matrix. Purification of IVT RNA was enabled with the adsorption of RNA to mesoporous silica in a spermidine-containing buffer and subsequent elution with EDTA. By differing EDTA concentration in the eluting buffer, we demonstrated that at least 80% of the dsRNA can be removed from the mesoporous silica-adsorbed RNA. When compared with the cellulose-based removal of dsRNA from IVT RNA, the mesoporous silica-based purification of IVT RNA using spermidine and EDTA in binding and elution, respectively, exhibited more effective removal of dsRNA contaminants from IVT RNA. Thus, mRNA purification with mesoporous silica particles as RNA adsorbents is applicable for the facile preparation of nonimmunogenic RNA suitable for in vivo uses.