Chelating Agent Ethylenediaminetetraacetic Acid Research Articles

Study on the enhancement effect of EDTA and oxalic acid on phytoremediation of Cr(VI) from soil using Datura stramonium L.

This study investigated the enhancing effects of soil treatment with ethylene diamine tetraacetic acid (EDTA) and oxalic acid (OA) on the remediation of Cr(VI) contaminated soil by Datura stramonium L. A greenhouse pot experiment was conducted, where Cr(VI) contaminated soil was treated with 100 mg/kg Cr(VI) and varying concentrations of EDTA (5 and 10 mmol/kg) and OA (5 and 10 mmol/kg). The effects of these soil treatments on biomass, chlorophyll content, antioxidant enzyme activities, and Cr(VI) enrichment and translocation efficiency of D. stramonium were evaluated. The results showed that added OA to soil significantly increased the biomass and chlorophyll content of D. stramonium. The addition of 10 mmol/kg of OA to soil increased the plant biomass by 67.16 % and chlorophyll b content by 40.01 %. In addition, OA soil treatment significantly enhanced the activities of superoxide dismutase (SOD) by 6.36 %, peroxidase (POD) by 163.13 %, catalase (CAT) by 36.92 %, and ascorbate peroxidase (APX) by 32.12 %, which effectively alleviated the oxidative stress induced by Cr(VI). In contrast, soil treatment with a high concentration of EDTA (10 mmol/kg) significantly reduced plant biomass and chlorophyll content, although it increased the biological concentration factor (BCF) of the stem and leaf, as well as the translocation factor (TF). In conclusion, appropriate amounts of EDTA and OA added to soil can enhance the phytoremediation efficiency of D. stramonium grown in Cr(VI) contaminated soil, with OA added to soil being more effective than addition of EDTA. This study revealed the potential mechanisms of chelating agents EDTA and OA in enhancing the phytoremediation of Cr(VI) contaminated soil by D. stramonium, providing a scientific basis for further optimization of phytoremediation techniques.

Impact of different disinfection protocols on the bond strength of NeoMTA 2 bioceramic sealer used as a root canal apical plug (in vitro study)

IntroductionTreatment of an immature permanent tooth required a special disinfection protocol due to the presence of thin radicular walls, which are prone to fracture. Mineral Trioxide Aggregate (MTA) has been proposed as a root repair material for root canal treatment. The aim of this in vitro study was to compare the push-out bond strength of conventional White MTA cements and second generation NeoMTA 2 in imitated immature roots treated with different disinfection protocols, which are 5.25% sodium hypochlorite (NaOCl), followed by 17% ethylenediaminetetraacetic acid (EDTA), and NaOCl, followed by 20% etidronic acid (HEBP).MethodsThe root canals of freshly extracted single-root teeth were manually prepared until 90 K-file to imitate immature roots. Roots were randomly divided into four groups (G) according to the disinfection protocol (n = 15 per group). where G1 (NaOCl + EDTA + White MTA) and G2 (NaOCl + EDTA + NeoMTA 2) While G3 (NaOCl + HEBP + White MTA) and G4 (NaOCl + HEBP + NeoMTA 2) All groups were activated with manual agitation. All specimens were incubated for 48 h. The apical third of each root was perpendicularly sectioned to attain a slice of 3 mm thickness. Push-out bond strength values were assessed using a two-way ANOVA and a Student’s t test.ResultsG3 and G4 that were treated with HEPB showed higher significant push-out bond strength mean values than G1 and G2 treated with an EDTA chelating agent. Irrespective of the chelating agent used, it was found that both NeoMTA 2 and White MTA had no significant influence on push-out bond strength mean values (p ≤ 0.05).ConclusionThe combined use of 5.25% NaOCl and 20% HEBP increased the push-out strength values of both NeoMTA 2 and White MTA, rendering them suitable to be used as an alternative chelating agent to EDTA.

Enhanced oil recovery and mitigating challenges in sandstone oil reservoirs employing EDTA chelating agent/ seawater flooding

While low salinity water (LSW) holds promise for improving oil recovery, its implementation is comparatively costly due to the substantial volumes of fresh water required to dilute seawater (SW). Additionally, concerns arise regarding potential issues related to LSW, including fines migration in sandstone reservoirs and scale formation in carbonate reservoirs. Chelating agents can be introduced into undiluted SW to bind with metal ions, thereby lowering its salinity. This approach mimics the behavior of LSW injection while overcoming associated challenges. This study involves measuring oil/injected solution interfacial tension (IFT), evaluating sandstone surface wettability alteration, along with conducting different sand pack flooding scenarios using Ethylenediaminetetraacetic acid (EDTA) chelating agent. The aim was to comprehend the EDTA oil recovery mechanisms and determine the optimal concentration of EDTA that minimizes chemical consumption while maximizing oil recovery. The findings indicated that incorporating 5 wt% EDTA into SW significantly reduced IFT from 29.52 mN/m to 4.75 mN/m, making the oil nearly miscible in the solution. Moreover, wettability tests confirmed that a minimum EDTA concentration of 5 wt% is required to shift wettability from oil-wet to strongly water-wet conditions. Sand pack flooding experiments, on the other hand, further demonstrated that this optimized fluid system can potentially recover an additional 16.1 % of oil following SW flooding. Finally, inductively coupled plasma (ICP) analysis revealed a notable increase in metal ion concentration during EDTA flooding, indicating enhanced leaching of metals from the sandstone surface and improved wettability characteristics.

A comparative study on the efficacy of conventional and green chelating agents for soil heavy metal remediation

Soil heavy metal contamination poses significant risks to ecological balance, vegetation, agricultural productivity, and human health due to the toxicity, persistence, and resistance to degradation of heavy metal ions. Chelation presents a widely employed method for heavy metal ion removal. While conventional chelating agents exhibit high removal efficiencies, they are associated with ecological hazards. In contrast, green chelating agents have gained prominence for their environmentally friendly attributes. This paper meticulously examines the heavy metal removal efficiencies, mechanisms, application advantages and limitations, as well as optimal pH ranges of both the traditional chelating agent Ethylenediaminetetraacetic acid (EDTA) and the green chelating agents Tetrasodium glutamate diacetate (GLDA), Methylglycine diacetic acid (MGDA), and [S, S]-ethylenediaminedisuccinic acid (EDDS). A comprehensive comparison reveals that EDDS exhibits superior performance followed by MGDA, GLDA, and EDTA, with MGDA displaying the broadest pH range spanning from 2 to 13.5. EDDS emerges as the most biodegradable option. Moreover, in terms of elimination rates, both MGDA and EDDS demonstrate comparable efficacy to EDTA. In conclusion, the green chelating agents scrutinized herein hold promise to potentially supplant conventional EDTA in large-scale practical applications.

High performance Mn/Mg co-modified calcium-based material via EDTA chelating agent for effective solar energy storage

Calcium-based material is a very promising candidate energy storage material for next generation concentrated solar power (CSP) plants with operation temperatures above 700 °C. However, performance decay and poor solar absorption capacity limit the large utilization of calcium-based material. Here, ethylene diamine tetraacetic acid (EDTA)-assisted sol–gel method is first employed to modify CaO with magnesium (Mg) and manganese (Mn) elements. MgO and Ca2MnO4 nanoparticles are attached to the surface of CaO particles to separate grains spatially to inhibit sintering. In addition to the external separation effect, Mn elements are found to be doped successfully into CaO crystal lattice rather than simply mixed, which restrains atomic diffusion and agglomeration inside CaO and thus further inhibits sintering more efficiently. The Mg and Mn co-doped sample (Ca:Mn:Mg = 9:1:2) synthesized by EDTA demonstrates exceptional thermal stability at 800 °C. The performance decay is only 6.3 % after 100 cycles and mainly manifests in the first ten cycles (4 %). Furthermore, by combining two-step calcination to avoid agglomeration and uneven doping, we also obtain the co-doped sample (Ca:Mn:Mg = 9:1:1) with nearly no performance decay in 100 cycles. The proposed materials possess an average solar absorptance of 67 %, about 4 times that of pure calcium material. This work not only designs energy storage materials with excellent performance expected to be applied in the next generation CSP plant but also provides a lattice doping route for calcium-based material modification.

Structural and magnetic properties of SmCo/Co nanocomposites elaborated using sol–gel auto-combustion strategy

Sm–Co nanomagnetic material has received much attention recently since it is thought to be the next generation of permanent magnets with potential uses in energy technologies. Here, ethylenediaminetetraacetic acid (EDTA) is utilized for the first time as a fuel source in a sol–gel auto-combustion process to synthesize Sm–Co nanoparticles. Then, reduction–diffusion process strategy followed the auto-combustion pathway. Typically, Sm2O3 and Co3O4 nanoparticles were prepared by combining Sm and Co nitrates with the chelating agent EDTA. The Sm–Co nanocomposites were subsequently created by reductively annealing precursor oxides using calcium powder. To display the temperature-dependent breakdown of the original precursor and determine the correct annealing temperature, TGA was employed to identify the annealing temperature and the precursor products. Additionally, other physical characterization techniques such as XRD, FE-SEM, EDX, and VSM were used for further investigations. Three distinct Sm1Cox compositions with different cobalt ratios (x = 4.0, 3.5, and 2.0) were prepared and studied. The findings demonstrate that the composition Sm1Cox (x = 2.0) led to the formation of hard phases of SmCo5, Sm2Co7, and Sm2Co17. These particles’ morphology reveals that they are made up of nanowires with an average thickness of 25 nm. As well, according to the VSM findings, this composite had the highest coercivity Hc and a maximum squareness ratio Mr/Ms, which were 2161 Oe and 0.57, respectively.

NdFeB magnet scrap valorization by leaching and recovery of rare earth metals by sorption on low-cost expanded clay

The search for new sources of rare earth metals (REM), such as neodymium and dysprosium, has ensued globally due to their strategic value for the sustainability of the energy sector. In this context, this work explored the potential of vermiculite as a sorbent for recovering rare earth cations from the leachate of end-of-life NdFeB magnets by kinetic, equilibrium, and desorption investigations. In which the REM uptake on vermiculite occurred by fast kinetics, and the significant sorbate-sorbate interactions at the equilibrium indicated that the REM sorption was a cooperative process; vermiculite sorbed the metals from the acid leachate in the following order: Fe(III) > Nd(III) > Zn(II) > Pr(III) > Co(II) > Dy(III) > Ni(II) > Al(III) > Mn(II); and the chelating agent ethylenediaminetetraacetic acid desorbed Nd(III) preferably over other metals, indicating the potential for further selective recovery processes. The characterization analyses indicated that the loaded vermiculite preserved the original structure, composition, functional groups, and thermal stability. Also, X-ray photoelectron spectroscopy corroborated the cation exchange mechanism between interlayer magnesium in the REM sorption. Thus, the experimental findings and a cost analysis compared to the literature demonstrated the cost-effectiveness and potential of vermiculite for the valorization of NdFeB magnet leachates.

A novel method to improve the morphology of Bi2212 film by PVA-assisted Pechini sol-gel method

Bi2212 high-temperature superconducting thin films (HTSFs) have emerged as the most promising material for terahertz (THz) devices due to their intrinsic Josephson effect. Enhancing the surface smoothness of these films is crucial for their practical application. In this study, metal nitrates were utilized as the raw material to prepare Bi2212 HTSFs on SrTiO3 (100) substrates using the Pechini sol-gel method. The chelating agent ethylenediamine tetraacetic acid (EDTA) and the surfactant polyvinyl alcohol (PVA) were employed to improve the dissolution characteristics of Bi2212 solution. The influence of various parameters such as sintering temperatures, surfactant concentrations, and metal ion ratios was systematically investigated to assess the phase purity, crystallinity, surface morphology, and electrical properties of the Bi2212 superconducting thin films. The results demonstrated that a higher concentration of PVA led to reduced solubility of the Bi2212 solution. Notably, when the PVA concentration was set at 1 %, the fabricated Bi2212 thin film exhibited exceptional epitaxial properties, enhanced Bi2212 phase purity, reduced surface roughness, and higher Tc. These outcomes provide valuable insights for the development of Bi2212 HTSFs in superconducting devices, as they serve as a reference point for achieving optimal film characteristics.

The identification, approaches to cleaning and removal of a lead-rich salt crust from the surface of an 18th century oil painting

A thin, grey surface layer was noticed after removing the varnish of an eighteenth century Dutch oil painting, by an unknown artist titled Vision of Saint Lutgard of Tongeren. This layer masked the paint layer almost entirely, casting a greyish veil that greatly influenced the painting’s appearance, colour, and saturation. Using scanning electron microscopy coupled with elemental analysis (SEM–EDX), this layer was identified as a lead-rich salt crust. The crust was a distinct layer on top of the paint layer, closely following the topography of the layer underneath but not embedded in it. The article discusses the possible theories behind the formation of this lead-rich salt crust by characterizing the painting’s material, past treatments, and environmental history. Furthermore, the article reports the decision-making process behind the removal of the crust, focusing specifically on the ethical and technical challenges of the cleaning treatment. Tests with different cleaning agents targeting separate components of the crust to remove it and different application techniques are described. The chelating agent Ethylenediaminetetraacetic acid (EDTA) was found to be the most effective in the removal of the crust and was chosen for its removal. The pH of the EDTA cleaning solution and its application had to be modified according to the colour of the paint the crust lay upon. Visual observations and analytical assessments using optical microscopy and SEM after cleaning indicate a successful reduction of the crust resulting in a significant improvement in the painting’s appearance.

Experimental Study on Catalytic Action of Intrinsic Metals in Coal Spontaneous Combustion.

In order to study the effect of inherent metals in coal on spontaneous combustion, Hongmiao lignite and Hongqingliang long-flame coal were demineralized by hydrochloric acid, the raw coal and demineralized coal were characterized by Fourier transform infrared spectrometry, X-ray diffraction, and synchronous thermal analysis experiments, and the corresponding ash content was detected by inductively coupled plasma mass spectrometry. The results show that the effect of demineralization on the volatile matter of low-rank coal is small, and the change of crystallite structure is not significant. The removed parts are mainly water-soluble salts and soluble minerals, such as carbonates and metal ions, that are not tightly bound to the organic matter of coal structure. The removed metal elements are mainly alkali metals Na and K, alkaline earth metals Ca, Mg, Sr, and Ba, and transition metals Fe, Mn, Ti, and so forth. The temperatures corresponding to the end of weight loss, ignition, and maximum weight loss rates were elevated on the thermogravimetric curves of the demineralized coal samples. The heat absorbed by evaporation of water in coal and the heat released by oxidation and combustion of coal are decreased to different degrees, indicating that the spontaneous combustion tendency of coal after demineralization is reduced, and alkali metal, alkaline earth metals, and transition metals in coal have a catalytic effect on spontaneous combustion of coal. After adding the metal chelating agent ethylenediaminetetraacetic acid (EDTA), the apparent activation energy decreased by 33.08 and 2.42%, respectively. EDTA and the alkali metal, alkaline earth metal, or transition-metal ions formed a stable chelate in coal. The catalytic activity of metals is weakened or even lost, thereby inhibiting spontaneous combustion of coal, and verifying the catalytic effect of internal metals in coal on the spontaneous combustion of coal.

Comparing the performance of demineralization agents (HCl and EDTA) for stable isotope analysis of bone collagen with implications for quality control criteria and collagen yield

AbstractStable isotope analysis of ancient bone collagen is a powerful technique for studying diet, migration, and ecology in archeological contexts. These analyses are, however, limited by collagen preservation and prohibitively low collagen yields. Harsh chemical demineralization is required to isolate the collagen from the mineral component of the bone, which in turn reduces the yield of material available for analysis. Demineralization is typically performed using hydrochloric acid (HCl), which reduces collagen yield via acid hydrolysis of peptide bonds. An alternative to a strong acid (HCl) treatment is the neutral chelating agent ethylenediaminetetraacetic acid (EDTA). To our knowledge, it has never been empirically tested whether EDTA treatment reduces collagen loss relative to HCl in samples that are known to be poorly preserved (i.e., low yields and/or collagen extracts failing other collagen quality control [QC] criteria). We tested the effect of the demineralization agent on collagen yield, stable isotope, and elemental composition of poorly preserved ancient bone samples. Collagen yield was significantly higher in EDTA‐treated samples; however, this did not translate into a greater number of samples passing relevant quality control criteria. Stable isotope compositions (SIC) were also not significantly different between treatments. The atomic C:N ratio of samples treated with EDTA was significantly lower than equivalent samples treated with HCl, which is likely a product of increased deamidation of asparagine and glutamine residues when collagen is demineralized with HCl relative to EDTA. We conclude that although EDTA treatment may reduce collagen loss relative to HCl treatment, this does not necessarily increase the probability of producing reliable–stable isotope data from bone samples yielding low amounts of collagen. Based on our isotopic data, we suggest the following provisional collagen QC criteria for EDTA‐demineralized samples: collagen yield > 2%, wt% C > 4%, wt% N > 2%, and atomic C:N ratio between 2.80 and 3.25.

The antifungal potential of the chelating agent EDTA against postharvest plant pathogen Botrytis cinerea

Botrytis cinerea is a phytopathogenic fungus that causes gray mold, a major postharvest disease of fruits and vegetables. Chemical fungicides remain the main solution to control Botrytis disease, but concerns have raised about their safety to environment and human health, and there is an increasing need for development of more effective and less toxic treatments. In this study the divalent cation chelating agent ethylenediaminetetraacetic acid (EDTA) exhibited marked antifungal activity against B. cinerea, including inhibition of spore germination, mycelial growth, infection cushion formation, stimulation of cell death, and impairment of fungal virulence. These adverse effects of EDTA could be reversed by the addition of calcium ion, implying that metal ion chelation is involved in the fungicidal mechanism. Bean leaf and tomato fruit protection assay indicated that EDTA treatment led to a significant reduction of infection by B. cinerea. Furthermore, the antifungal activity of EDTA was significantly enhanced when used in combination with fenhexamid. These findings suggest that EDTA could be a promising tool to control B. cinerea, and application of EDTA may reduce the use of conventional chemical fungicides.

Experimental Investigation and Modeling of Fluid and Carbonated Rock Interactions with EDTA Chelating Agent during EOR Process

The injection of chemical fluids into oil reservoirs is gaining widespread attention in light of the declining conventional oil resources by recovering more hydrocarbons. This study is focused on using a chemical called ethylenediaminetetraacetic acid (EDTA) chelating agent in a carbonate reservoir to shed light on contact angle differences of 625 aged thin sections and rock dissolution under the influence of different pHs, temperatures, chelating times, and various chelating agent concentrations in seawater. According to a rock dissolution test, at least 5 wt % of EDTA chemical is needed to obtain oil recovery. A ζ potential test and scanning electron microscopy (SEM) images revealed that the mechanism of adsorption at low pH values and the expansion of the electrical double layer (EDL) at high pH values were responsible for wettability alteration, and an increase in EDTA concentration intensified each mechanism. Interfacial tension (IFT) measurements also showed that adding 1 and 10 wt % of the EDTA to the seawater solution reduced the IFT by 67.75% and 76.08%, respectively. The contact angle experiments demonstrated an increase in the mechanism that leads rock to behave more hydrophilically as pH, solution temperature, and chelating agent concentration in saltwater increased. Artificial neural network (ANN) methods also led to the introduction of a model to predict the contact angle employing multilayer perceptron neural networks (MPNN) and cascade feedforward neural networks (CFFNN). The CFFNN with two hidden neurons and trained by the Levenberg–Marquardt backpropagation algorithm is the most accurate model when comparing the accuracy of models for predicting contact angle values. The CFFNN model indicated that the weight percentage of the chelating chemical, which has a share of about 90%, had the greatest influence on the contact angle, and chelating time, with a share of less than 10%, had the least.

Difference in the Inhibitory Effect of Thiol Compounds and Demetallation Rates from the Zn(II) Active Site of Metallo-β-lactamases (IMP-1 and IMP-6) Associated with a Single Amino Acid Substitution

Gram-negative bacteria producing metallo-β-lactamases (MBLs) have become a considerable threat to public health. MBLs including the IMP, VIM, and NDM types are Zn(II) enzymes that hydrolyze the β-lactam ring present in a broad range of antibiotics, such as N-benzylpenicillin, meropenem, and imipenem. Among IMPs, IMP-1 and IMP-6 differ in a single amino acid substitution at position 262, where serine in IMP-1 is replaced by glycine in IMP-6, conferring a change in substrate specificity. To investigate how this mutation influences enzyme function, we examined lactamase inhibition by thiol compounds. Ethyl 3-mercaptopropionate acted as a competitive inhibitor of IMP-1, but a noncompetitive inhibitor of IMP-6. A comparison of the crystal structures previously reported for IMP-1 (PDB code: 5EV6) and IMP-6 (PDB code: 6LVJ) revealed a hydrogen bond between the side chain of Ser262 and Cys221 in IMP-1 but the absence of hydrogen bond in IMP-6, which affects the Zn2 coordination sphere in its active site. We investigated the demetallation rates of IMP-1 and IMP-6 in the presence of chelating agent ethylenediaminetetraacetic acid (EDTA) and found that the demetallation reactions had fast and slow phases with a first-order rate constant (kfast = 1.76 h-1, kslow = 0.108 h-1 for IMP-1, and kfast = 14.0 h-1 and kslow = 1.66 h-1 for IMP-6). The difference in the flexibility of the Zn2 coordination sphere between IMP-1 and IMP-6 may influence the demetallation rate, the catalytic efficiency against β-lactam antibiotics, and the inhibitory effect of thiol compounds.

From the Free Ligand to the Transition Metal Complex: FeEDTA- Formation Seen at Ligand K-Edges.

Chelating agents are an integral part of transition metal complex chemistry with broad biological and industrial relevance. The hexadentate chelating agent ethylenediaminetetraacetic acid (EDTA) has the capability to bind to metal ions at its two nitrogen and four of its carboxylate oxygen sites. We use resonant inelastic X-ray scattering at the 1s absorption edge of the aforementioned elements in EDTA and the iron(III)-EDTA complex to investigate the impact of the metal–ligand bond formation on the electronic structure of EDTA. Frontier orbital distortions, occupation changes, and energy shifts through metal–ligand bond formation are probed through distinct spectroscopic signatures.

Iodine determination in mineral water using ICP-MS: Method development and analysis of brands available in Israeli stores

Reliable iodine determination in drinking water samples has gained importance in the last few decades, mostly due to intensive use of both desalinized water that lacks several important nutritional elements, and bottled mineral water. ICP-MS is a sensitive method for iodine determination that must be performed under alkaline conditions because of the volatile nature of some iodine species. However, in water samples with high pH (>10), slow precipitation of calcium (Ca) and/or magnesium (Mg) carbonates leads to clogging of the ICP-MS nebulizer. We propose preventing this precipitation by adding the chelating agent ethylenediaminetetraacetic acid (EDTA) at 0.1% to a 2% ammonium hydroxide matrix. This concentration of EDTA sufficed for most drinking water samples studied, as long as a 1:1 molar ratio of EDTA to Ca+Mg concentration in the water was maintained. The limit of quantitation of the developed method for iodine was < 0.1 µg L−1. The average iodine concentration in various brands of bottled mineral water sold in Israel was relatively low (average value of seven brands ± standard deviation was 7.67 ± 6.38 µg I L−1). . Regular consumption of either desalinated water or bottled mineral water probably does not supply enough iodine to eliminate iodine deficiency in Israeli consumers. Therefore, continuous follow-up of the iodine status in both tap and bottled water is strongly recommended.

Attenuation of ischemia–reperfusion injury by intracoronary chelating agent administration

Ischemia–reperfusion (IR) injury accelerates myocardial injury sustained during the myocardial ischemic period and thus abrogates the benefit of reperfusion therapy in patients with acute myocardial infarction. We investigated the efficacy of intracoronary ethylenediaminetetraacetic acid (EDTA) administration as an adjunctive treatment to coronary intervention to reduce IR injury in a swine model. We occluded the left anterior descending artery for 1 h. From the time of reperfusion, we infused 50 mL of EDTA-based chelating agent via the coronary artery in the EDTA group and normal saline in the control group. IR injury was identified by myocardial edema on echocardiography. Tetrazolium chloride assay revealed that the infarct size was significantly lower in the EDTA group than in the control group, and the salvage percentage was higher. Electron microscopy demonstrated that the mitochondrial loss in the cardiomyocytes of the infarcted area was significantly lower in the EDTA group than in the control group. Echocardiography after 4 weeks showed that the remodeling of the left ventricle was significantly less in the EDTA group than in the control group: end-diastolic dimension 38.8 ± 3.3 mm vs. 43.9 ± 3.7 mm (n = 10, p = 0.0089). Left ventricular ejection fraction was higher in the EDTA group (45.3 ± 10.3 vs. 34.4 ± 11.8, n = 10, respectively, p = 0.031). In a swine model, intracoronary administration of an EDTA chelating agent reduced infarct size, mitochondrial damage, and post-infarct remodeling. This result warrants further clinical study evaluating the efficacy of the EDTA chelating agent in patients with ST-segment elevation myocardial infarction.

Effect of cadmium and ethylenediamine tetraacetic acid supplementation on cadmium accumulation by roots of Brassica species in Cd spiked soil.

Cadmium (Cd) metal extraction through efficient plant roots has attracted much attention as this methodology is environment-friendly and cost-effective. Brassica species are well known for their tolerance towards high Cd concentration in contaminated soils. The tolerance ability may vary among species; hence the assessment of this variability is mandatory for selecting Brassica species. For this purpose, a greenhouse pot experiment was carried out using three Brassica species (Brassica juncea L., Brassica campestris L., and Brassica napus L.). To evaluate the effect of chelating agent ethylenediamine tetraacetic acid (EDTA) on Cd uptake, EDTA (0, 1, and 2 g kg-1 soil) was supplemented along with Cd (0, 5, 10, 20, 40, and 80 mg kg-1 soil). Among different species, B. juncea possessed the highest root dry biomass and lowest root Cd concentration in untreated soil. Overall root dry biomass of all tested Brassica species reduced on increasing Cd and EDTA levels. The trend was appeared to be related to an increase in root Cd concentration on the supplementation of EDTA that formed a complex with the target metal contaminate and resulted in vacuolar sequestration. Roots of B. juncea showed maximum Cd accumulation and highest values at Cd and EDTA levels up to 20 mg kg-1 and 1 g kg-1 soil due to the combined effect of root biomass and Cd concentration in roots. Thus, present findings inferred that Cd and EDTA supplementation might prove as a feasible strategy to improve remediation of Cd-polluted soil using B. juncea as an efficient Cd accumulator.

Effect of Treatment Conditions on Matrix Stimulation of Carbonate Rocks with Chelating Agents

This study aimed to optimize the acidizing efficiency during stimulation treatments with chelating agents. The performance of hydroxylethylethylenediaminetriacetic acid (HEDTA), diethylenetriaminepentaacetic acid (DTPA), and ethylenediaminetetraacetic acid (EDTA) in stimulating carbonate rocks were investigated. In this paper, the effect of injection rate, chemical type, pH, and concentration on the stimulation performance was studied. Also, the optimum treatment conditions were identified utilizing the acid volume and treatment time. Different measurements were carried out, including solubility tests, coreflooding experiments, and CT scan analysis. Solubility tests were performed to study the impact of solution concentration and pH on the performance of the chelating agent. Coreflooding experiments were carried out at high-pressure, high-temperature conditions to assess the performance of chelating agents in different treatment situations. In addition, CT scan analysis was carried out before and after the acid injections to capture the changes induced in the carbonate matrix due to the stimulation treatment. The success of acidizing treatment was identified by the creation of the dominant wormholes. The pressure-drop profiles and the CT scan analysis were used to confirm the generation of wormholes. Finally, the normalized volume and time to breakthrough were utilized to identify the optimum treatment conditions. In this work, chelating agents successfully created dominant wormholes (WHs) in carbonate rocks at different injection rates and treatment conditions. However, applying an injection rate between 0.7 and 1 cm3/min significantly improved the acidizing performance and reduced the acid volume that was required to create wormholes. EDTA and HEDTA chelating agents showed better performance at low pH. Using a solution pH of 4.5 resulted in reducing the acid volume by 30% compared to using a solution pH of 10 at the same conditions. However, DTPA chelating agent showed better performance at high pH, and dominant WHs were created at a pH of 12 using less acid volume. Finally, the optimum acidizing treatment can be achieved by using EDTA chelating agent with a concentration of 9.25 wt.% and pH of 4.5. Applying the optimum treatment parameters can reduce the acid volume by 40% and the chemical cost by a factor of 6, on average. Overall, this study indicates that chelating agents’ solution can be injected at optimum conditions in terms of chemical concentration, pH, and injection rate, to maximize the treatment efficiency and reduce the cost.

A Novel Weissella cibaria Strain UTNGt21O Isolated from Wild Solanum quitoense Fruit: Genome Sequence and Characterization of a Peptide with Highly Inhibitory Potential toward Gram-Negative Bacteria.

A novel Weissella cibaria strain UTNGt21O from the fruit of the Solanum quitoense (naranjilla) shrub produces a peptide that inhibits the growth of both Salmonella enterica subsp. enterica ATCC51741 and Escherichia coli ATCC25922 at different stages. A total of 31 contigs were assembled, with a total length of 1,924,087 bases, 20 contig hits match the core genome of different groups within Weissella, while for 11 contigs no match was found in the database. The GT content was 39.53% and the genome repeats sequences constitute around 186,760 bases of the assembly. The UTNGt21O matches the W. cibaria genome with 83% identity and no gaps (0). The sequencing data were deposited in the NCBI Database (BioProject accessions: PRJNA639289). The antibacterial activity and interaction mechanism of the peptide UTNGt21O on target bacteria were investigated by analyzing the growth, integrity, and morphology of the bacterial cells following treatment with different concentrations (1×, 1.5× and 2× MIC) of the peptide applied alone or in combination with chelating agent ethylenediaminetetraacetic acid (EDTA) at 20 mM. The results indicated a bacteriolytic effect at both early and late target growth at 3 h of incubation and total cell death at 6 h when EDTA was co-inoculated with the peptide. Based on BAGEL 4 (Bacteriocin Genome Mining Tool) a putative bacteriocin having 33.4% sequence similarity to enterolysin A was detected within the contig 12. The interaction between the peptide UTNGt21O and the target strains caused permeability in a dose-, time- response manner, with Salmonella (3200 AU/mL) more susceptible than E. coli (6400 AU/mL). The results indicated that UTNGt21O may damage the integrity of the cell target, leading to release of cytoplasmic components followed by cell death. Differences in membrane shape changes in target cells treated with different doses of peptide were observed by transmission electronic microscopy (TEM). Spheroplasts with spherical shapes were detected in Salmonella while larger shaped spheroplasts with thicker and deformed membranes along with filamentous cells were observed in E. coli upon the treatment with the UTNGt21O peptide. These results indicate the promising potential of the putative bacteriocin released by the novel W. cibaria strain UTNGt21O to be further tested as a new antimicrobial substance.