Influence Of Fulvic Acid Research Articles

Fulvic Acid Enhances Nitrogen Fixation and Retention in Paddy Soils through Microbial-Coupled Carbon and Nitrogen Cycling.

Fulvic acid, the most soluble and active humic substance, is widely used as an agent to remediate contaminated soils and improve soil fertility. However, the influence of fulvic acid (FA), as a microbial carbon source, on carbon and nitrogen cycles in paddy soils remains elusive. Therefore, to investigate it, an incubation experiment was conducted. Gas analyses indicated that the carbon dioxide and methane emissions were enhanced in FA treatment, which increased up to 94.08-fold and 5.06-fold, respectively. 15N-labeling experiments revealed that nitrogen fixation capability was promoted (1.2-fold) to reduce the carbon and nitrogen imbalance due to fulvic acid amendment. Metagenomic analysis further revealed that gene abundances of degradation of lignin-like compounds, gallate degradation, methanogenesis, nitrogen fixation, and urea hydrolysis increased, while the bacterial ammonia oxidation and anaerobic ammonium oxidation decreased, caused by FA application. Metabolic reconstruction of metagenome-assembled genomes revealed that Azospirillaceae, Methanosarcinaceae, and Bathyarchaeota, with higher abundance in FA treatment, were the key microorganisms to maintain the carbon and nitrogen balance. The metabolic pathways of fulvic acid degradation and coupled nitrogen fixation and retention were constructed. Collectively, our results provided novel insights into the theoretical basis of the use of humic substances for reducing nitrogen fertilization and climate change.

Reductive dissolution of As-bearing iron oxides: Mediating mechanism of fulvic acid and dissimilated iron reducing bacteria

Fulvic acid (FA) and iron oxides often play regulating roles in the geochemical behavior and ecological risk of arsenic (As) in terrestrial ecosystems. FA can act as electron shuttles to facilitate the reductive dissolution of As-bearing iron (hydr)oxides. However, the influence of FA from different sources on the sequential conversion of Fe/As in As-bearing iron oxides under biotic and abiotic conditions remains unclear. In this work, we exposed prepared As-bearing iron oxides to FAs derived from lignite (FAL) and plant peat (FAP) under anaerobic conditions, tracked the fate of Fe and As in the aqueous phase, and investigated the reduction transformation of Fe(III)/As(V) with or without the presence of Shewanella oneidensis MR-1. The results showed that the reduction efficiency of Fe(III)/As(V) was increased by MR-1, through its metabolic activity and using FAs as electron shuttles. The reduction of Fe(III)/As(V) was closely associated with goethite being more conducive to Fe/As reduction compared to hematite. It is determined that functional groups such as hydroxy, carboxy, aromatic, aldehyde, ketone and aliphatic groups are the primary electron donors. Their reductive capacities rank in the following sequence: hydroxy> carboxy, aromatic, aldehyde, ketone> aliphatic group. Notably, our findings suggest that in the biotic reduction, Fe significantly reduction precedes As reduction, thereby influencing the latter's reduction process across all incubation systems. This work provides empirical support for understanding iron's role in modulating the geochemical cycling of As and is of significant importance for assessing the release risk of arsenic in natural environments.

Anti-Inflammatory Property Establishment of Fulvic Acid Transdermal Patch in Animal Model

The formulation of the transdermal patch with fulvic acid (FA) on an emulsion basis using pluronic Kolliphor® p237 as a permeability enhancer was developed and studied for anti-inflammatory properties. FA was isolated from the peat in the Nizhny Novgorod region of Russia and characterized as a potential active pharmaceutical ingredient. In vitro studies of the release of FA from the transdermal patch, as well as the FA penetration through the acetyl cellulose membrane using the Franz diffusion cell, showed its high efficiency (56% and 90%, respectively, in 8 h). In the in vivo experiment, qualitative and quantitative features of the rat knee caused by complete Freund’s adjuvant-induced arthritis (morphological changes, the FA influence on the biochemical indexes) were studied. The inflammatory process that developed within 15 days was accompanied by the activation of antioxidant oxidoreductase enzymes (by 50–70%), the increase in the cross-sectional diameter of the cartilage, and the increase in the values of marker indicators of the process of rheumatoid arthritis. Within 7 days of treatment, under the influence of FA, the values of ESR, RF, leukocytes, C-reactive protein, as well as the biochemical parameters characterizing oxidative stress (SOD, catalase, glutathione reductase, LDH, G6PD) normalized, and the edema reduced. These results may be useful for arthritis treatment using the transdermal patch with FA.

Influence of Fulvic Acid on the Increase in Lifespan and the Physiological State of Bees

Influence of Fulvic Acid on the Increase in Lifespan and the Physiological State of Bees

The Influence of Fulvic Acid on Egg Laying of the Queen Bee in the Spring Period and the Productivity of the Bee Colony

The Influence of Fulvic Acid on Egg Laying of the Queen Bee in the Spring Period and the Productivity of the Bee Colony

Influence of Peat Soil Environment on Mechanical Properties of Cement-Soil and Its Mechanism

The influence of peat soil environment (PSE) on the mechanical properties of cement-soil in the area around Dianchi Lake and Erhai Lake in Yunnan Province has attracted much attention. This study explores the change law of cement-soil UCS in the PSE, and provides guidance for the development and sustained usage of peat soil foundation. The paper discusses the preparation of cement-soil samples by adding humic acid (HA) and cement to cohesive soil with low organic matter content (blending method) and soaking it in fulvic acid (FA) solution and deionized water (steeping method) to simulate the actual working environment of cement-soil. Unconfined compressive strength (UCS), acid consumption, ion leaching, scanning electron microscope (SEM), and X-ray diffraction (XRD) tests are carried out on cement-soil samples soaked for 90 days. The results show that HA can significantly reduce the UCS of cement-soil. FA can reduce the UCS of cement-soil when the content of HA is less than 18%. However, when the amount of HA is more than 18%, the UCS of cement-soil increases slightly. FA makes the deformation and failure type of cement-soil gradually change from brittle shear failure to plastic shear failure. FA reacts with the cement hydration products in the sample so that the cumulative acid consumption of the cement-soil sample continues to increase, and the dissolution of Ca2+, Mg2+, Al3+, and Fe3+ in the sample increases the ion concentration of the soaking solution. In addition, SEM and XRD show that HA can increase the macropores and connectivity of cement-soil, while FA fills part of the pores of the wetting layer. In the PSE, FA can strengthen the inner structure of HA particles and fill and cement the layers of cohesive particles, enhancing the construction of cement-soil with HA content greater than 18%, so that its UCS is relatively improved. However, when the amount of HA is less than 18%, there are more small pores in the cement-soil. The interaction between FA and HA in the cement-soil is weak. The influence of FA on cement-soil is mainly a weakening effect, and its UCS is relatively reduced.

Inhibition mechanisms of humic acid and protein on the degradation of sulfamethazine by horseradish peroxidase

Humic acid and protein are not only common organic matters in surface water, but also the main components of the extracellular polymer of microorganisms, which can influence on the biotransformation and biodegradation of antibiotics by enzymes. Therefore, the influence of fulvic acid and protein on the biotransformation of sulfamethazine (SMR) by horseradish peroxidase (HRP) was explored. HPLC-MS analysis show that 79.7% of SMR (20 mg/L) was degraded by sulfa bond breaking, hydroxyl substitution and pyrimidine ring opening, while the removal rate was suppressed significantly in the presence of fulvic acid or bovine serum albumin (BSA, model protein). This inhibition is related to the concentration of fulvic acid or BSA, but not to the exposure time. The inhibition of fulvic acid on SMR degradation by HRP is mainly achieved by binding to the HRP-SMR intermediate to prevent the HRP-SMR intermediate from further generating HRP and products, which is called anticompetitive inhibition. HRP activity is not affected by the addition of BSA with time. The inhibition of BSA on SMR degradation by HRP may be achieved by competing with HRP for binding to SMR, which is confirmed with the analysis of molecular docking. • Fulvic acid or protein (BSA) inhibits the degradation of sulfamethazine by HRP. • The inhibition is related to the concentration of fulvic acid or BSA but not to time. • Competitive inhibition of protein on the degradation of sulfamethazine by HRP. • Anticompetitive inhibition of humic acid on the degradation of sulfamethazine by HRP.

Influence of fulvic acid in feed additives on protein change and dairy productivity of cows

The main task of animal husbandry is to obtain large volumes of products: increasing the weight gain of cows and milk yields in a short time at minimal cost. The existing feeding standards for cattle are based on the use of Class 1 feed. In farms, most feed contains a low concentration of nutrients, the feeding of which does not allow to maintain the standard ratio of the diet. The quality of milk is not only of economic importance, which determines the profitability and competitiveness of dairy products in the market, but also of social significance, which is associated with the impact on human health. The most important factor determining the quality of milk and its suitability for further processing is the fullness of animal feeding: the energy value of the feed ration, the ratio of basic nutrients. The article presents data on the effect of the feed additive "Furor" based on fulvic acid, developed by LLC "Esson", which.

The influence of fulvic acid on spring cereals and sugar beets seed germination and plant productivity

The vegetations and fields experiments were conducted in 2017–2018 at Rumokai Experimental Station of the Lithuanian Research Centre for Agriculture and Forestry. The influence of naturally occurring fulvic acids on the germination of spring wheat and barley and sugar beet seeds, development of plants and their yield and quality was investigated. The use of fulvic acids for seed dressing reliably increased the final germination percentage and decreased the mean germination time in spring wheat, spring barley, and sugar beet. It significantly reduced the number of spring wheat sprouts damaged by Fusarium sp. and the number of spring barley sprouts damaged by Fusarium sp. and Microdochium nivale. Fulvic acids increased the length of spring wheat and barley shoots and the air-dry weight of shoots and roots. The use of fulvic acids during plant vegetation reliably increased spring wheat grain yield and sugar beet roots yield, and improved yield quality.Combinations of fulvic acids with pesticides were also investigated. The use of fulvic acids in combination with pesticides used in sugar beet crops improved the action of those pesticides, so it was possible to reduce the rates used, thus reducing environmental pollution.

Influence of fulvic acid on Pb(II) removal from water using a post-synthetically modified MIL-100(Fe)

HypothesisModification of MIL-100(Fe) with ethanediamine (ED) is expected to improve the removal percentage of Pb(II) ions from aqueous solution. Nevertheless, the adsorption performance of ED-MIL-100(Fe) in natural waters will be affected by natural organic matter such as fulvic acids (FA). Hence, it is necessary to study the influence of FA on the physicochemical property, adsorption behavior and mechanisms of ED-MIL-100(Fe) towards the removal of Pb(II) from water. ExperimentsBatch adsorption experiments were conducted to compare adsorption capacity of MIL-100(Fe) and ED-MIL-100(Fe) for Pb(II). In addition, XRD, FTIR, SEM and XPS techniques were applied to investigate the characteristics, adsorption isotherms, and kinetics in the presence and absence of FA. FindingsED-MIL-100(Fe) enabled 99% removal of Pb(II) from water at or below 60 mg L−1, whereas the MIL-100(Fe) hardly adsorbed any Pb(II). Additionally, the adsorption percentage of the Pb(II) ions (76%) outcompeted that of other metal ions (i.e. Co, Cu, Ni, Zn, and Cd) (each ≤ 25%) in the mixed solution. The negative surface charge of ED-MIL-100(Fe) was not affected by FA. Increasing FA concentration steadily increased the functional groups surrounding the ED-MIL-100(Fe) via electrical interaction, thus facilitating the Pb(II) ions adsorption.

Adsorption of phosphate by sediments in a eutrophic lake: Isotherms, kinetics, thermodynamics and the influence of dissolved organic matter

Adsorption and desorption of phosphorus (P) at sediment-water interface is one of the key processes of biogeochemical cycling of P in lakes. Thus, adsorption of phosphate by sediments from Lake Dianchi, a eutrophic lake, was investigated in this study. Importantly, the influence of dissolved organic matter (DOM) with fulvic acid (FA) as a representative example on these processes was further studied. The results showed that the presence of FA in the solution did not change the tendency of phosphate adsorption by sediments from Lake Dianchi. Compared with Freundlich equation, Langmuir model fitted better in describing the adsorption isotherms. And the pseudo-second-order kinetic model predicated well the adsorption kinetics for adsorption of phosphate by sediments. Under low concentrations of phosphate, FA promoted desorption of phosphate adsorbed on the sediments. However, adsorption behaviors including capacity and efficiency would be enhanced by presence of FA under high concentrations of phosphate. Based on adsorption thermodynamics, temperature and DOM (FA in this study) were two most important factors for adsorption of phosphate by sediments. Adsorption of phosphate on sediments was a spontaneous endothermic reaction process, which was a chemical-physical process rather than a simple physical adsorption. The influence of FA on the adsorption of phosphate by sediments was closely related with characteristics of sediments such as contents of Fe-Al oxides and organic matter. Aggressive results showed that increasing DOM due to algal blooming was likely an important way for dominant algae to maintain the nutrients such as P in lakes.

Can Carbamates Undergo Radical Oxidation in the Soil Environment? A Case Study on Carbaryl and Carbofuran.

Radical oxidation of carbamate insecticides, namely carbaryl and carbofuran, was investigated with spectroscopic (electron paramagnetic resonance [EPR] and UV-vis) and theoretical (density functional theory [DFT] and ab initio orbital-optimized spin-component scaled MP2 [OO-SCS-MP2]) methods. The two carbamates were subjected to reaction with •OH, persistent DPPH• and galvinoxyl radical, as well as indigenous radicals of humic acids. The influence of fulvic acids on carbamate oxidation was also tested. The results obtained with EPR and UV-vis spectroscopy indicate that carbamates can undergo direct reactions with various radical species, oxidizing themselves into radicals in the process. Hence, they are prone to participate in the prolongation step of the radical chain reactions occurring in the soil environment. Theoretical calculations revealed that from the thermodynamic point of view hydrogen atom transfer is the preferred mechanism in the reactions of the two carbamates with the radicals. The activity of carbofuran was determined experimentally (using pseudo-first-order kinetics) and theoretically to be noticeably higher in comparison with carbaryl and comparable with gallic acid. The findings of this study suggest that the radicals present in soil can play an important role in natural remediation mechanisms of carbamates.

Influence of fulvic acid on the colloidal stability and reactivity of nanoscale zero-valent iron

This study investigated the effect of fulvic acid (FA) on the colloidal stability and reactivity of nano zero-valent iron (nZVI) at pH 5, 7 and 9. The sedimentation behavior of nZVI differed at different pH. A biphasic model was used to describe the two time-dependent settling processes (i.e., a rapid settling followed by a slower settling) and the settling rates were calculated. Generally, the settling of nZVI was more significant at the point of zero charge (pHpzc), which could be varied in the presence of FA due to the adsorption of FA on the nZVI surface. More FA was adsorbed on the nZVI surface at pH 5–7 than pH 9, resulting in the varying sedimentation behavior of nZVI via influencing the electrostatic repulsion among particles. Moreover, it was found that there was a tradeoff between the stabilization and the reactivity of nZVI as affected by the presence of FA. When FA concentration was at a low level, the adsorption of FA on the nZVI surface could enhance the particle stabilization, and thus facilitating the Cr(VI) reduction by providing more available surface sites. However, when the FA concentrations were too high to occupy the active surface sites of nZVI, the Cr(VI) reduction could be decreased even though the FA enhanced the dispersion of nZVI particles. At pH 9, the FA improved the Cr(VI) reduction by nZVI. Given the adsorption of FA on the nZVI surface was insignificant and its effect on the settling behavior of nZVI particles was minimal, it was proposed that the FA formed soluble complexes with the produced Fe(III)/Cr(III) ions, and thus reducing the degree of passivation on the nZVI surface and facilitating the Cr(VI) reduction.

Peculiarities of the Influence of Fulvic Acids on the Development of Plankton Algae

Peculiarities of the Influence of Fulvic Acids on the Development of Plankton Algae

Fulvic acid affects proliferation and maturation phases in Abies cephalonica embryogenic cells

Embryogenic cell masses (ECM) of Abies cephalonica were grown on proliferation media in the presence and absence of fulvic acid (FA), whose molecular composition and conformational rigidity were evaluated by CPMAS- 13C NMR spectroscopy. To assess the physiological effects of this humic material during proliferation and maturation stages of somatic embryogenesis (SE), proliferation rate, proportion of consecutive developmental stages of pro-embryogenic masses (PEM), cellular ATP and glucose-6-phosphate were evaluated at regular intervals. FA increased the proliferation rate, especially during the early sampling days, and the percentage of PEM in their advanced developmental stage. Cellular ATP and glucose-6-phospahte were increased by FA pre-treatment during the maturation phase. Furthermore, the effects of the anti-auxin p-chlorophenoxyisobutyric acid (PCIB), such as a decrease of growth and the enhancement of PEM III induction, were inverted by FA. Proton pumping ATPase and PPase activities were decreased in microsomes from PCIB-treated ECM, while they increased in the presence of FA. This fulvic matter also induced a delay in somatic embryo formation during the maturation phase. Both the improvement of the PEM proliferation and the reduction of the subsequent maturation process of A. cephalonica are explained by a release from the complex humic structure of low molecular-weight molecules, which may interact with the plant hormonal signaling pathway. These effects appear to be related to the hydrophilic and conformationally labile nature of FA. The structure–activity relationship observed here suggests that the influence of FA on ECM may be attributed to specific bioactive molecules that are preferentially released from the FA loose superstructure.

Influence of fulvic acid and hydroxy propyl-β-cyclodextrin on aspirin degradation

Objective: The degradation of aspirin (ASA) was investigated to reveal information about the influence of complexation with fulvic acid (FA), as a new complexing agent and compared with hydroxy propyl-β-cyclodextrin complex. Materials and methods: ASA was complexed with FA in the molar ratio 1:0.5, 1:1, and 1:2 by different methods through lyophilization, solvent evaporation, and spray drying. Spray-dried (1:1) ASA–hydroxy propyl-β-cyclodextrin complex was prepared and compared with optimized complex of FA. All the complexes and ASA alone were packaged in well-labeled sealed polythene-lined aluminum pouches and stored in stability chamber at 40 ± 2°C and 75 ± 5% relative humidity for 120 days. Samples were analyzed for salicylic acid content at 0, 30, 60, 90, and 120 days. Results: Overall 4.31% salicylic acid was formed in 1:1 ASA–FA spray-dried complex, which was optimized stable complex among other complexes of FA prepared by different methods in different molar ratios. However, 2.35% salicylic acid was measured with 1:1 spray-dried ASA–hydroxy propyl-β-cyclodextrin complex. Stability of ASA increased more when complexed with hydroxy propyl-β-cyclodextrin as compared to FA. Conclusions: A novel complexing agent in the form of FA was investigated to increase the stability of ASA. A marked improvement in stability of ASA was observed when complexed with hydroxy propyl-β-cyclodextrin (1:1) by spray drying as compared to 1:1 spray-dried ASA–FA complex.

Influence of fulvic acid and hydroxy propyl-β-cyclodextrin on aspirin degradation

Influence of fulvic acid and hydroxy propyl-β-cyclodextrin on aspirin degradation

Influence of contact time, pH, soil humic/fulvic acids, ionic strength and temperature on sorption of U(VI) onto MX-80 bentonite

The sorption of U(VI) from aqueous solution on MX-80 bentonite was studied as a function of contact time, pH, ionic strength, solid contents, humic acid (HA), fulvic acid (FA) and temperature under ambient conditions using batch technique. The results indicate that sorption of U(VI) on MX-80 bentonite is strongly dependent on pH and ionic strength. The removal of U(VI) to MX-80 bentonite is rather quick and the kinetic sorption data is simulated well by a pseudo-second-order rate equation. The presence of HA enhances the sorption of U(VI) on MX-80 bentonite obviously, but the influence of FA on U(VI) sorption is not obvious. The thermodynamic parameters (ΔH0, ΔS0, and ΔG0) for the sorption of U(VI) calculated from temperature dependent sorption suggest that the sorption reaction is endothermic and spontaneous.

Influence of Fulvic Acids and Copper Ions on Thiram Determination in Water

The literature concerning the application of solid-phase extraction (SPE) to the concentration of thiram (bis(dimethyldithiocarbamoyl) disulfide) from natural waters is scarce, the available results being contradictory or with no analytical significance. To clarify these contradictory results, a C18-SPE procedure combined with HPLC-UV was applied to thiram analysis in river water, and the influence of several factors on recoveries was studied. This procedure gave thiram recoveries of about 100% when applied to thiram standard solutions. However, when the same procedure was applied to river water samples spiked with thiram, the recoveries depended on the equilibration time after spiking. The influence of river fulvic acids (FAs) and Cu(II) on thiram recoveries from standard solutions was studied as a possible interference for such a result. In the presence of FA, thiram recoveries were always higher than 85%. In the presence of Cu(II), thiram recoveries decreased significantly, due to complexation, but the addition of an excess of EDTA before C18-SPE eliminated that interference, and thiram was completely recovered. However, in river water samples the addition of EDTA had to be done before thiram spiking to obtain a recovery >90%. Thiram standard solutions containing both river FA and Cu(II) showed a behavior similar to the one observed in river water samples. On the basis of these results, the catalytic effect of Cu(II) on the degradation of thiram by FA, with formation of a Cu(II)-dimethyldithiocarbamate complex, was hypothesized.

Influence of Fulvic Acids on the Migration of Metals in the "Bottom Sediments - Water" System

Influence of Fulvic Acids on the Migration of Metals in the "Bottom Sediments - Water" System