Interaction Of Phosphate Research Articles

Investigation of resistance ratios and resistance mechanisms of Cydia pomonella (L.) (lepidoptera: Tortricidae) populations collected from apple orchards in Isparta (Türkiye) against some insecticides

The codling moth, Cydia pomonella is an important pest that causes significant economic losses in apples and walnuts in the world. The aim of this study was to investigate, for the first time in Türkiye, the resistance status and resistance mechanisms of codling moth, Cydia pomonella against indoxacarb, deltamethrin and emamectin benzoate. All apple orchard populations developed resistance ratios ranging from 3.38 to 22.37-fold to deltamethrin, 5.67–29.87-fold to indoxacarb and 1.46–3.05-fold to emamectin benzoate. The interaction of some synergists triphenyl phosphate (TPP), piperonyl butoxide (PBO) and diethyl maleate (DEM) with indoxacarb and deltamethrin was analyzed in the susceptible, MAREM and Tepeli populations with moderate resistance to indoxacarb and deltamethrin. While indoxacarb + TPP showed a significant synergistic effect only in MAREM population, a significant synergistic effect was observed with indoxacarb + TPP and indoxacarb + PBO in Tepeli population. The activities of detoxifying enzymes [esterase, glutathion –S– transferase (GST) and cytochrome P450 monooxygenase (P450)] studied by biochemical methods showed some variation depending on the population. The results of biochemical analyses showed that esterase and GST enzyme activities of all populations was between 0.51 and 0.94, 0.77 and1.29 mOD min−1mg−1 proteins, respectively. The P450 enzyme activities ranged from 0.53 to 0.78, RFU min−1mg−1 proteins. In addition, the L1014F knockdown mutation (CTT to TTT) corresponding to leucine to phenylalanine amino acid substitution of the voltage-gated sodium channel in Cydia pomonella was determined in MAREM and Tepeli populations. It was determined that while MAREM and Tepeli populations developed moderate resistance, the other populations developed a low level resistance to deltamethrin and indoxacarb. On the other hand, all populations developed a low level resistance to emamectin benzoate. The P450 and esterase enzyme activities were significantly higher in MAREM and Tepeli populations which were resistant to deltamethrin and indoxacarb than the susceptible population. In addition, a Kdr point mutation L1014F was detected in the deltamethrin resistant MAREM and Tepeli populations.

Lipopeptide antibiotics disrupt interactions of undecaprenyl phosphate with UptA

The peptidoglycan pathway represents one of the most successful antibacterial targets with the last critical step being the flipping of carrier lipid, undecaprenyl phosphate (C55-P), across the membrane to reenter the pathway. This translocation of C55-P is facilitated by DedA and DUF368 domain-containing family membrane proteins via unknown mechanisms. Here, we employ native mass spectrometry to investigate the interactions of UptA, a member of the DedA family of membrane protein from Bacillus subtilis, with C55-P, membrane phospholipids, and cell wall-targeting antibiotics. Our results show that UptA, expressed and purified in Escherichia coli, forms monomer-dimer equilibria, and binds to C55-P in a pH-dependent fashion. Specifically, we show that UptA interacts more favorably with C55-P over shorter-chain analogs and membrane phospholipids. Moreover, we demonstrate that lipopeptide antibiotics, amphomycin and aspartocin D, can directly inhibit UptA function by out-competing the substrate for the protein binding, in addition to their propensity to form complex with free C55-P. Overall, this study shows that UptA-mediated translocation of C55-P is potentially mediated by pH and anionic phospholipids and provides insights for future development of antibiotics targeting carrier lipid recycling.

Long-term interaction of metals and phosphate with ferrihydrite in artificial seawater and implications for past and present environments

The FeIII hydroxide ferrihydrite (Fh) is highly reactive towards dissolved metals and other aqueous compounds. This reactivity suggests a possible role for Fh in environmental remediation and in controlling ambient concentrations of metals and nutrients in both modern and ancient aqueous environments. Though the reactivity of Fh towards a variety of aqueous compounds has been determined in previous studies, its reactivity under seawater-like conditions has not been systematically explored. Since solution chemistry can have a profound effect on the uptake of metals and oxyions through its effects on the surface chemistry of Fh and the speciation of metals in solution, the dearth of experiments under seawater-like conditions translates into a knowledge gap of metal-Fh interactions in natural marine systems. Furthermore, metal- and nutrient-Fh interactions have been investigated under dissimilar conditions, making a quantitative comparison of these interactions difficult. Lastly, the fate of the aqueous metals and nutrients taken up by Fh upon its aging has been examined in only a few studies and mostly for a duration up to ∼8 months.We bridged these gaps in a series of adsorption and co-precipitation experiments of various metals and phosphate with Fh, in seawater-analog solutions, at circumneutral pH (pH 7.5 and 8.0) and 25 °C. We quantified the effect of interaction with Fh on the aqueous concentrations of CdII, CoII, CrVI, CuII, MnII, MoVI, NiII, VV, UVI, ZnII, and phosphate (PO43−). The experimental results are provided as uptake percentages (quantified as the metal:Fe ratio in the solid phase relative to the metal:Fe ratio added) at different metal:Fe ratios and as a series of partition coefficients of the studied metals and PO43− between aqueous solution and Fh. Additionally, aging experiments of up to ∼4 years in duration were used to determine the potential effects of grain coarsening, surface modification and mineral transformation on the uptake of the metals and PO43−. Uptake of CrVI, MoVI and UVI was negligible in both the adsorption and co-precipitation experiments. Uptake of VV and PO43− by co-precipitation was as much as twice their uptake by adsorption, and we suggest that stabilization of colloidal Fh with a large surface area explains these findings. For CuII, NiII, CoII, MnII, and CdII differences in uptake between the co-precipitation and adsorption experiments were less pronounced, and we ascribe these differences to relatively minor incorporation of these metals into Fh. No significant transformation of Fh to more stable phases was observed under our experimental conditions and duration. Nevertheless, the uptake of several metals and phosphate was affected by Fh aging. Approximately 75% of the PO43− initially taken up by co-precipitation with Fh was released, as was approximately 30% of the VV. A pronounced increase in the uptake of MnII may be related to its oxidation and precipitation as MnIII,IV oxides. For other metals the changes in uptake were less pronounced.We discuss the mechanisms of metal and PO43− uptake by Fh, the effects of solution composition on uptake, and the implications of our findings for modern and ancient natural environments and for environmental remediation.

Phosphate and zinc interaction in soil and plants: a reciprocal cross-talk

Phosphate and zinc interaction in soil and plants: a reciprocal cross-talk

How Does Mg2+(aq) Interact with ATP(aq)? Biomolecular Structure through the Lens of Liquid-Jet Photoemission Spectroscopy.

Liquid-jet photoemission spectroscopy (LJ-PES) allows for a direct probing of electronic structure in aqueous solutions. We show the applicability of the approach to biomolecules in a complex environment, exploring site-specific information on the interaction of adenosine triphosphate in the aqueous phase (ATP(aq)) with magnesium (Mg2+(aq)), highlighting the synergy brought about by the simultaneous analysis of different regions in the photoelectron spectrum. In particular, we demonstrate intermolecular Coulombic decay (ICD) spectroscopy as a new and powerful addition to the arsenal of techniques for biomolecular structure investigation. We apply LJ-PES assisted by electronic-structure calculations to study ATP(aq) solutions with and without dissolved Mg2+. Valence photoelectron data reveal spectral changes in the phosphate and adenine features of ATP(aq) due to interactions with the divalent cation. Chemical shifts in Mg 2p, Mg 2s, P 2p, and P 2s core-level spectra as a function of the Mg2+/ATP concentration ratio are correlated to the formation of [Mg(ATP) 2]6-(aq), [MgATP]2-(aq), and [Mg2ATP](aq) complexes, demonstrating the element sensitivity of the technique to Mg2+-phosphate interactions. The most direct probe of the intermolecular interactions between ATP(aq) and Mg2+(aq) is delivered by the emerging ICD electrons following ionization of Mg 1s electrons. ICD spectra are shown to sensitively probe ligand exchange in the Mg2+-ATP(aq) coordination environment. In addition, we report and compare P 2s data from ATP(aq) and adenosine mono- and diphosphate (AMP(aq) and ADP(aq), respectively) solutions, probing the electronic structure of the phosphate chain and the local environment of individual phosphate units in ATP(aq). Our results provide a comprehensive view of the electronic structure of ATP(aq) and Mg2+-ATP(aq) complexes relevant to phosphorylation and dephosphorylation reactions that are central to bioenergetics in living organisms.

Energy landscapes of homopolymeric RNAs revealed by deep unsupervised learning

Conformational dynamics of RNA plays important roles in a variety of cellular functions such as transcriptional regulation, catalysis, scaffolding, and sensing. Recently, RNAs with low-complexity sequences have been shown to phase separate and form condensate phases similar to lowcomplexity protein domains. The affinity for phase separation and the material characteristics of RNA condensates are strongly dependent on sequence composition and patterning. We hypothesize that differences in the affinities for RNA phase separation can be uncovered by studying sequence-dependent conformational dynamics of single RNA chains. To this end, we have employed atomistic simulations and deep dimensionality reduction techniques to map temperature-dependent conformational free energy landscapes for 20 base-long homopolymeric RNA sequences: poly(U), poly(G), poly(C), and poly(A). The energy landscapes of homopolymeric RNAs reveal a plethora of metastable states with qualitatively different populations stemming from differences in base chemistry. Through detailed analysis of base, phosphate, and sugar interactions, we show that experimentally observed temperature-driven shifts in metastable state populations align with experiments on RNA phase transitions. Specifically, we find that the thermodynamics of unfolding of homopolymeric RNA follows the poly(G) > poly(A) > poly(C) > poly(U) order of stability, mirroring the propensity of RNA to form condensates. To conclude, this work shows that at least for homopolymeric RNA sequences the single-chain conformational dynamics contains sufficient information for predicting and quantifying condensate forming affinities of RNAs. Thus, we anticipate that atomically detailed studies of temeprature -dependent energy landscapes of RNAs will be a useful guide for understanding the propensity of various RNA molecules to form condensates.

Unraveling the Microscopic Mechanism of Molecular Ion Interaction with Monoclonal Antibodies: Impact on Protein Aggregation.

Understanding and predicting protein aggregation represents one of the major challenges in accelerating the pharmaceutical development of protein therapeutics. In addition to maintaining the solution pH, buffers influence both monoclonal antibody (mAb) aggregation in solution and the aggregation mechanisms since the latter depend on the protein charge. Molecular-level insight is necessary to understand the relationship between the buffer-mAb interaction and mAb aggregation. Here, we use all-atom molecular dynamics simulations to investigate the interaction of phosphate (Phos) and citrate (Cit) buffer ions with the Fab and Fc domains of mAb COE3. We demonstrate that Phos and Cit ions feature binding mechanisms, with the protein that are very different from those reported previously for histidine (His). These differences are reflected in distinctive ion-protein binding modes and adsorption/desorption kinetics of the buffer molecules from the mAb surface and result in dissimilar effects of these buffer species on mAb aggregation. While His shows significant affinity toward hydrophobic amino acids on the protein surface, Phos and Cit ions preferentially bind to charged amino acids. We also show that Phos and Cit anions provide bridging contacts between basic amino acids in neighboring proteins. The implications of such contacts and their connection to mAb aggregation in therapeutic formulations are discussed.

Interactions of phosphate, phosphine oxide and phosphoramide ligands with Th(IV)

The complexation behavior of phosphate, phosphine oxide, and phosphoramide ligands with Th(IV) is investigated at the Density Functional Theory (DFT) level. Employing Energy Decomposition Analysis (EDA), the study reveals significant contributions of geometric strain and dispersion interactions in determining the stability of these complexes. It is observed that the orbital interaction in the various Th(IV) complexes increases in the order phosphate < phosphine oxide < phosphoramide.

A Study on Ikaite Growth in the Presence of Phosphate

Phosphate is a common component in natural growth solutions of ikaite. Although phosphate often occurs as a minor constituent, its presence may promote the formation of ikaite as it significantly inhibits the precipitation of calcite. The interactions of phosphate with ikaite and the role of a potential uptake of phosphate by ikaite, however, are poorly understood. In this study, the influence of phosphate on ikaite growth at 1 °C was investigated. Ikaite- and calcite-seeded growth experiments were conducted in cryo-mixed-flow reactors at saturation ratios 1.5 ≤ Ωikaite ≤ 2.9 (Ω = ionic activity product/solubility product). From these growth experiments, the rate constant k = 0.10 ± 0.03 µmol/m2/s and the reaction order n = 0.8 ± 0.3 were derived for ikaite. The reaction order implies a transport- or adsorption-controlled growth mechanism which supports a low energy pathway of ikaite growth via an attachment of hydrous CaCO30 complexes without any extensive dehydration of aqueous species as, for instance, required for calcite growth. A potential depletion of aqueous phosphate due to an uptake by ikaite growth was not detectable. Furthermore, growth retardation by phosphate, as known for calcite growth, was not evident. Thus, a significant incorporation of phosphate into growing ikaite could be precluded for the conditions applied in this study. The observed lack of incorporation of phosphate agrees with the previously suggested growth mechanism via the attachment of hydrous CaCO30 complexes which likely does not facilitate substantial substitution of carbonate by phosphate ions.

Enabling Smart Agriculture through Sensor-Integrated Microfluidic Chip to Monitor Nutrient Uptake in Plants

The soil microenvironment greatly influences a plant’s ability to absorb nutrients and germinate. Sensing these changes in soil medium is critical to understand plant nutrient requirements. Soil being dynamic represents changes in nutrient content, element mobility, texture, water-holding capacity, and microbiota which affects the nutrient levels. These minor changes affect the plant in early growth and development and studying these changes has always been challenging. Microfluidics provides a platform to study nutrient availability and exchange in small volumes of liquid or media resembling plant microenvironments. Here, we have developed a novel microfluidic chip-embedded molecular imprinted sensor for sensing nitrate and phosphate in the media. For data acquisition and recording we have implemented a potentiostat controlled via a microcontroller allowing data storage and transfer via a long-range radio module (LoRA). The microfluidic device’s functionality was validated by germination of the legume crimson red and recoding the nitrate and phosphate levels in media for 7 d. The MIP-based sensor measures nitrate and phosphate, in the range from 1 to 1000 mM. The accuracy of detection for nitrate and phosphate showed 99% and 95% respectively. The chip coupled with MIP based sensor for nutrient analysis serves as a platform technology for studying nitrate and phosphate nutrient exchange and interaction. This chip in the future can be implemented to study plant deficiencies, drought resistance, and plant immunity.

Produksi Dan Mutu Benih Dasar Padi (Oryza Sativa L.) Varietas Membramo Pada Aplikasi Pupuk Humic Acid Super Phospate Dan Kaptan Super Phospate

Rice plants (Oryza sativa L) are food plants in the form of clumping grasses, as well as ancient plants originating from Asia and West Africa which are tropical and subtropical climates. This study aims to determine the effect of the interaction of Humic Acid Super Phosphate (HSP) and Kaptan Super Phosphate (KSP) on the basic seed production of rice (Oryza sativa. L) of the Membrano variety. This study used a factorial randomized block design (RBD) using 2 treatment factors. The first factor is HSP consisting of 3 levels, namely A0 : without HSP, A1 : 100 kg/ha and A2 : 200 kg/ha. The second factor is KSP consisting of 3 levels, namely P1: 200 kg/ha, P2: 300 kg/ha and P3: 400 kg/ha. The results obtained were then analyzed using ANOVA (Analysis of Variance) with a level of 5%. This study used the parameters of number of tillers, number of productive tillers, number of per panicle gabai, number of per panicle good grain, percentage of empty grain, and seed production per hectare. The results showed that the administration of HSP had a very significant effect on the parameters of the number of tillers, the number of productive tillers, the number of per panicle grain, the number of per panicle good grain, the percentage of empty grain and seed production per Ha. Meanwhile, the addition of KSP showed a very significant effect on the parameters of the number of per panicle grain, the number of non-sticky grain per panicle, the percentage of empty grain and had a significant effect on the parameter of seed production per Ha, but did not have a significant effect on the number of tillers. The interaction between HSP and KSP administration did not have a significant effect on all parameters, except for the number of productive tillers and production per hectare.

Enhanced mechanical and dielectric properties of lamellar aluminum phosphate/bismaleimide composites by interface modification with maleimidopropyl triethoxysilane

AbstractIn this work, the two‐step modification process is designed to improve the dispersity and interfacial interaction of lamellar aluminum phosphate (LAP) nanoparticles (NPs). The LAP NPs are successfully modified by maleimidopropyl triethoxysilane (MPTES). LAP/blend bismaleimide (BBMI) composites were prepared by mechanical blending process. Among them, the flexural strength of the modified LAP/BBMI composites were significantly enhanced with more than 148.2 MPa, the characteristic heat resistance temperature (T40) was improved by 11.7°C, and the carbon residue rate (Y600) also increased by 8.8%. Specifically, the dielectric constant of the modified LAP/BBMI composites only display a slight enhancement, but the dielectric loss is reduced to lower than 0.015. The results are helpful to potentially apply in the fields of electromagnetic and wave transparent materials.

Fluorometric investigation of boric acid-pyridoxal 5′ phosphate interaction: A turn-on-fluorescence assay for the detection of boric acid in water bodies and fetal bovine serum

Boron is a trace element that is beneficial to plants as well as human and animal health. Boron supplementation is beneficial for absorbing vitamin D and magnesium, activating antioxidant enzymes and anticancer treatments. However, environmental accumulation of boron exceeding the permissible limit harms plants, animals and humans. Boric acid (BA), a form of boron, is known to interact with biomolecules such as NAD+/NADH, vitamin C, vitamin D, vitamin B1 and vitamin B6 determined through techniques like NMR, mass spectrometry, and FTIR. The fluorescence interaction of BA with the biologically active form of vitamin B6, Pyridoxal 5′ phosphate (PLP), has not been explored to date. Therefore, this study reports the interaction mechanism of BA with PLP via fluorescence spectroscopy analysis. The absorption, excitation and fluorescence lifetime measurements indicate that BA may form a complex through the mono or di-esterification of the phenolic hydroxyl group and aldehyde of PLP at different pH, forming the boronate esters. BA addition enhanced the fluorescence intensity of PLP by 12–22-fold in phosphate buffer (at acidic, neutral, and basic pH conditions). On the other hand, in citrate buffer at pH 4.0, BA enhanced PLP fluorescence by 28-fold. The binding constant for BA in phosphate buffer and citrate buffer was found to be 173 mol−1·L and 623 mol−1·L, respectively. At the same time, the detection limit for BA was found to be 445 μg/L and 212 μg/L in respective buffers. Therefore, PLP was used as a turn-on fluorescent probe to detect and quantify BA in water bodies and fetal bovine serum (FBS). The developed method successfully detected BA in environmental water bodies, achieving an average recovery rate of 99.84% (with a relative standard deviation (RSD) of 0.38%) in phosphate buffer and 81.59% (RSD, 4.56%) in citrate buffer. Furthermore, detecting BA in PLP-spiked FBS has been demonstrated in citrate buffer at pH 4.0, yielding an average recovery rate of 108.25% (RSD, 3.19%). Therefore, this study provides a basis for understanding the interaction of biomolecules like vitamins with boronates which aid in development of novel boronate based therapeutics and also helps in understanding the metabolic reactions of vitamin derivatives using fluorescence spectroscopy.

Surface‐enhanced Raman spectroscopy investigation of PO43− to Ag/Al2O3 nanopatterned substrates binding and its dynamics for sensitive detection of phosphate in water

AbstractWe provide fast and sensitive detection of phosphate dissolved in water using Raman spectroscopy. To this end, phosphate‐scavenging planar core/shell surface‐enhanced Raman spectroscopy (SERS) probes consisting of Al2O3‐capped Ag nanopatterned sapphire substrate were prepared and optimized. Thanks to scavenging, the probes provide enhancement sufficient to readily detect phosphate at levels occurring in water sources. In particular, the SERS probes were successfully tested for selective detection of all phosphate ions and down to 1 M phosphate concentration (30 g/L of phosphorus in the solution). The novelty of our contribution lies in real‐time SERS monitoring of the phosphate Raman markers, which allowed to study the dynamics of phosphate interaction with the nano‐structured surface of the probes. Under natural conditions (neutral to basic environment), the phosphates adsorb on the probes in form of PO in two steps.

Interaction of calcium responsive proteins and transcriptional factors with the PHO regulon in yeasts and fungi.

Phosphate and calcium ions are nutrients that play key roles in growth, differentiation and the production of bioactive secondary metabolites in filamentous fungi. Phosphate concentration regulates the biosynthesis of hundreds of fungal metabolites. The central mechanisms of phosphate transport and regulation, mediated by the master Pho4 transcriptional factor are known, but many aspects of the control of gene expression need further research. High ATP concentration in the cells leads to inositol pyrophosphate molecules formation, such as IP3 and IP7, that act as phosphorylation status reporters. Calcium ions are intracellular messengers in eukaryotic organisms and calcium homeostasis follows elaborated patterns in response to different nutritional and environmental factors, including cross-talking with phosphate concentrations. A large part of the intracellular calcium is stored in vacuoles and other organelles forming complexes with polyphosphate. The free cytosolic calcium concentration is maintained by transport from the external medium or by release from the store organelles through calcium permeable transient receptor potential (TRP) ion channels. Calcium ions, particularly the free cytosolic calcium levels, control the biosynthesis of fungal metabolites by two mechanisms, 1) direct interaction of calcium-bound calmodulin with antibiotic synthesizing enzymes, and 2) by the calmodulin-calcineurin signaling cascade. Control of very different secondary metabolites, including pathogenicity determinants, are mediated by calcium through the Crz1 factor. Several interactions between calcium homeostasis and phosphate have been demonstrated in the last decade: 1) The inositol pyrophosphate IP3 triggers the release of calcium ions from internal stores into the cytosol, 2) Expression of the high affinity phosphate transporter Pho89, a Na+/phosphate symporter, is controlled by Crz1. Also, mutants defective in the calcium permeable TRPCa7-like of Saccharomyces cerevisiae shown impaired expression of Pho89. This information suggests that CrzA and Pho89 play key roles in the interaction of phosphate and calcium regulatory pathways, 3) Finally, acidocalcisomes organelles have been found in mycorrhiza and in some melanin producing fungi that show similar characteristics as protozoa calcisomes. In these organelles there is a close interaction between orthophosphate, pyrophosphate and polyphosphate and calcium ions that are absorbed in the polyanionic polyphosphate matrix. These advances open new perspectives for the control of fungal metabolism.

Insights into the selectivity of metallic oxides for arsenic and phosphate from EXAFS and DFT calculations

Phosphate is the biggest competitor for arsenic removal. Nanoscale metal oxides (NMOs) are commonly used to treat arsenic-contaminated water, yet their selective adsorption mechanisms for arsenic and phosphate are poorly understood. We quantified the selectivity of iron oxide (Fe2O3), zinc oxide (ZnO), and titanium dioxide (TiO2) nanosheets for arsenic in systems containing arsenic and phosphate, and determined the interaction of phosphate and arsenate/arsenite on metal oxide surfaces through batch experiments, spectroscopic techniques, and DFT calculations. We found that Fe2O3, TiO2, and ZnO nanosheets exhibit selectivity for arsenate/arsenite in the presence of phosphate, with Fe2O3 the most selective, followed by TiO2 and ZnO. The bonding mechanism on these metallic oxide surfaces dominates the selectivity. The more stable inner-sphere complexes of arsenate on the surfaces of Fe2O3 (bidentate binuclear), TiO2 (bidentate binuclear), and ZnO nanosheets (tridentate trinuclear) contribute to their preference for arsenate over phosphate. This difference in arsenate selectivity can be reflected in the difference in adsorption energy, net electron transfer number, and M − O bond length of the most stable inner sphere complexes. Overall, our study elucidated the selective adsorption mechanisms of arsenate/arsenite on Fe2O3, TiO2, and ZnO surfaces and highlighted the need to consider the competition between arsenate and phosphate during their removal from contaminated water.

Enhanced recovery of phosphate from wastewater using hollow hierarchical hydrotalcite/hydroxide composite microspheres adsorbent

The release of untreated phosphate into water systems is of great environmental concern, thus many adsorption methods have been developed to deal with this issue. In the present paper, we prepared magnesium/aluminum (Mg/Al)-based hydrotalcite/Al(OH)3 adsorbent with a hierarchical structure using a hydrothermal approach. Tests were conducted to assess variation in the Al/Mg mole ratio, interaction time, solution pH, competitive adsorption, and initial concentration of anions on the uptake of phosphate anions. The outcome revealed that 96.8 % of phosphate could be adsorbed within 2 h using the sample with an Al-to-Mg molar ratio of 1:3 (AM-3) with Langmuir theoretical maximum adsorption rate of 94.08 mg-P/g at 25 °C, which is 1.59 and 5.98 times higher than MgO (M) and Al2O3 (M) samples, respectively. The equilibrium experiment outcomes were fitted with the isotherm kinetic models and the results confirmed an adsorption mechanism involving surface adsorption that introduced phosphate ions into the layered structure of composite. The improved phosphate adsorption on AM-3 sample was attributed to the interaction of phosphate and hydroxyl ions during the adsorption. According to our experimental findings, the hydrotalcite prepared offers a great deal of promise for application as an adsorbent for the recovery of phosphate in environmental remediation.

Two-dimensional solid-state NMR spectroscopy investigations of surface precipitation of phosphate onto calcite

The interaction of phosphate with typical soil minerals is important for understanding P cycling in natural and agricultural systems. We investigated the mechanisms of kinetics of phosphate uptake onto calcite using solid-state NMR spectroscopy. At a low phosphate concentration of 0.5 mM, the 31P single-pulse solid-state NMR peak revealed the formation of amorphous calcium phosphate (ACP) within the initial 30 min, which transformed to carbonated hydroxyapatite (CHAP) after 12 d. At a high phosphate concentration (5 mM), the results showed transformation from ACP to OCP, later to brushite, and eventually to CHAP. The formation of brushite is further supported by 31P{1H} heteronuclear correlation (HETCOR) spectra via a correlation of δP–31 = 1.7 ppm and the 1H peak at δH–1 = 6.4 ppm, which denotes the structure water of brushite. Furthermore, 13C NMR directly revealed both A-type and B-type CHAP. Generally, this work provides a detailed understanding of the aging effect on the phase transition scale of phosphate surface precipitation onto calcite in soil environments.

Systemic adaptation of rice plants under low phosphate conditions and interaction with endophytic bacteria

Phosphate (Pi) is essential for plants. Plants have adapted mechanisms to overcome Pi deficiencies. This study examined the interaction of two contrasting rice varieties (G22 and G299) and two endophytic bacterial strains. Four different culture media were established: full Pi (P0), Pi starvation (P*), insoluble Pi with Pi-solubilizing Burkholderia sp. strain 205 (P+205), or Pi-insolubilizing strain 113 (P+113). We investigated the responses of rice to these media. Root length and weight and the number of crown roots were higher in the P* and P+113 medium than the two other media. However, shoot length, and weight were lower. Most amino acid families were higher in the P+113 medium than in the other media. The roots of G299 plants in the P+113 medium showed the highest relative expression of all phosphate-analyzed genes; however, these genes were expressed at low levels in the leaves of both rice varieties. Notably, the jasmonic acid gene OsJAZ5 showed the highest expression in the roots of G299 plants in the P+113 medium. Our results demonstrate the strong effects of the different genetic backgrounds of bacteria and rice plants on the response to low Pi. We also demonstrate the involvement of jasmonic acid in low Pi and soluble-phosphate-bacteria interaction in G299 plants. A positive interaction between Burkholderia sp. strain 205 and rice plants has been noticed in the promotion of plant growth. Further studies under field conditions should be undertaken to develop this potential strain as a biofertilizer.

The interaction of triglycidyl phosphate with europium nitrate and properties of obtained metal-containing polymer

The interaction of phosphorus-containing epoxy trifunctional monomer – triglycidyl phosphate (TGPhT), with europium (III) nitrate hexahydrate is studied. A dissolution of europium salt added into TGPhT is occurred due to the interaction of the cation with phosphoryl groups and oxygen atoms of the epoxy ring, that is accompanied by the opening reaction and led to the formation of a polymer. The interaction of triepoxide with salt is investigated by FTIR-spectroscopy and differential scanning calorimetry (DSC). The thermal stability of the samples is determined by combined method of thermogravimetry and differential scanning calorimetry (TG/DSC), coupled with a quadrupole mass spectrometry to identify the gaseous products evolved during the thermal analysis of the samples. The kinetic parameters of the curing reaction are computed by using Thermokinetics software. The interaction of TGPhT with europium nitrate is suggested to occur through opening of epoxy rings in the presence of europium ions via the mechanism of cationic polymerization. The cured epoxy polymer exhibits luminescent properties.