Phosphate Research Articles

Enhanced biodegradation of glyphosate by Chlorella sorokiniana engineered with exogenous purple acid phosphatase

Organophosphate pesticides, particularly glyphosate, persist in aquatic environments due to widespread agricultural usage, posing substantial environmental and health risks. This study explores the bioremediation potential of genetically engineered Chlorella sorokiniana, expressing purple acid phosphatase (PAP) from Phaeodactylum tricornutum, for glyphosate biodegradation. The engineered strain (OE line) demonstrated complete glyphosate biodegradation at concentrations below 10 ppm within 4–6 days, surpassing the wild type (WT). Enhanced biodegradation in the OE line was attributed to increased growth and ATP levels due to the release of inorganic phosphate, indicating enhanced metabolic efficiency. Photosynthetic parameters, as well as chlorophyll, and carotenoid contents, were significantly improved, driving higher biomass accumulation. Metabolic shifts toward lipogenesis were observed, supported by the upregulation of triacylglycerol-related genes. Additionally, antioxidant enzyme activities (GPx, SOD, CAT) were elevated in the OE line, mitigating oxidative stress. Importantly, the overexpression of PAP activated and upregulated the level of endogenous CsPAP18, which displayed stable binding with glyphosate and its metabolite aminomethylphosphonic acid, highlighting the synergistic role of PAP and CsPAP18 in glyphosate biodegradation. The OE line effectively treated glyphosate-contaminated real wastewater, confirming the feasibility of engineered strain for environmental remediation. This study provides valuable insights into the potential of engineered microalgae for effective and sustainable wastewater treatment, specifically targeting the removal of organophosphate contaminants in freshwater environments.

Differential Expression of Phosphate Starvation-responsive Genes among Sweetpotato Cultivars during Establishment and Onset of Storage Root Formation

It has been documented that sweetpotato (Ipomoea batatas L.) cultivars vary in morphological and physiological adaptations to low phosphorus (P) availability but knowledge of the underlying molecular mechanisms is largely unknown. The objective of this research was to generate cultivar-specific information about phosphate starvation response (PSR) genes to variations in inorganic phosphate (Pi) availability at the onset of storage root formation among sweetpotato cultivars. Cultivars Bayou Belle (BB), Evangeline (EV), and Orleans (OR) were grown under varying Pi levels: 0 mg·L−1 (low Pi), 15 mg·L−1 (Pi-sufficient), and 31 mg·L−1 (high Pi). Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) analysis of PSR genes IbPHR1, IbSPX1, IbSPX3, IbPHT1;4, IbPHT1;5, and IbNLA was performed at 5 and 10 days after planting (DAP), corresponding to adventitious root system establishment and the onset of storage root formation, respectively. The cultivar BB grown under low Pi showed significantly higher expression of all genes except IbPHR1. The cultivar OR grown in both low and high Pi exhibited upregulation of IbPHR1. On the other hand, EV grown under low Pi revealed no response for all genes investigated. Exposure of BB to high Pi resulted in a decrease in expression for all genes except IbNLA. The cultivar EV grown in high Pi conditions showed increase in expression for IbSPX1, IbPHT1;5, and IbNLA. Expression pattern difference among cultivars relative to Pi levels corroborates field observations showing that BB, EV, and OR have different Pi requirements. The increased activity of BB PSR genes grown under low Pi supports the hypothesis that BB requires low P fertilizer input relative to OR and EV. Results from this study corroborate findings from well-characterized crop species and model systems and pave the way for the development of tools and practices to increase phosphorus use efficiency in sweetpotato.

Quantifying the reversibility of ATP hydrolysis in rabbit skeletal myosin subfragment 1 using a luciferase assay

BackgroundIt is known that the adenosine triphosphate (ATP) hydrolysis in a number of ATPases is reversible. Radioactive methods are standard in measuring ATPase reversibility. We used myosin as a well-studied model enzyme to develop a luciferase-based assay to quantify the reversibility of ATP hydrolysis. In myosin, ATP bound to the active site is hydrolyzed into adenosine diphosphate (ADP) and inorganic phosphate (Pi) and recombined back into ATP multiple times before products of hydrolysis are released. The reversibility of ATP hydrolysis by skeletal myosin was previously confirmed using radioactively labeled isotopes. Transient kinetics studies indicated that the ATP hydrolysis step is temperature-sensitive, with a dissociation equilibrium constant of 1.6 at 3 °C. Consequently, the association equilibrium constant at this temperature is 0.63. The goal of our work was two-fold, (a) to develop a luciferase-based assay to measure the equilibrium constant of enzymatic ATP hydrolysis, eliminating the need for radioactively labeled Pi, and (b) refine the value of the association equilibrium constant of the myosin ATPase hydrolysis step.MethodsIn this assay, a reaction mixture containing myosin and saturating levels of ADP and Pi was incubated to reach equilibrium, then the reaction was terminated, and the amount of ATP produced by myosin was quantified using the luciferase assay. The equilibrium constant of ATP hydrolysis was defined as the ratio of ATP to ADP bound to myosin.ResultsWe obtained a value of 0.78 ± 0.14 for the association equilibrium constant of ATP hydrolysis at 0 °C. 50 μM ADP bound to myosin is turned into 21.9 ± 3.0 μM ATP. Our result is in excellent agreement with the literature data, supporting the viability of the new methodology.DiscussionThis methodology allows a more accessible and safe option to measure ATP production and reversibility of ATPase enzymes. Standard laboratory equipment is utilized in the assay, and the number of steps in the developed assay is reduced significantly compared to the radioactive method.

The impact of exogenous ketone body suppletion on energy and pH balance in skeletal muscle during exercise in chronic heart failure patients: a prospective randomized double-blind cross-over study

Abstract Background Heart Failure (HF) is characterized by impediments in exercise capacity. Disruptions in the energy metabolism of skeletal muscle contribute to this condition. Pre-clinical and clinical evidence showed that reductions in carbohydrate and FA metabolism in HF may be partially overcome by a compensatory increase in ketone body oxidation and suggest that suppletion of ketone bodies (KB) may improve energy metabolism in HF. Purpose We tested the effect of exogenous KB suppletion on energy and pH balance during cycling exercise using 31P Magnetic Resonance (MR) Spectroscopy of the exercising quadriceps muscle in patients with HF. Methods In a randomized, double-blind, placebo-controlled cross-over study, 14 stable HF patients with reduced ejection fraction and diminished exercise capacity underwent maximal exercise testing in a MR scanner fitted with a cycling ergometer after KB or placebo treatment. Phosphocreatine (PCr) and inorganic phosphate (Pi) resonance amplitudes and frequencies were measured continuously in the quadriceps muscle during rest, exercise and recovery using in-vivo 31P MR spectroscopy (Figure 1). Results Patients had a median age of 66 [53 – 75] years, were 14% female, had a median LVEF of 37% [27 – 40] and circulating NT-pro BNP levels of 411 [182 – 946] pg/mL. Peak oxygen uptake (VO2) was 18.2 [15.2 – 20.3] ml/kg/min, which is 68% [62 – 78%] of predicted. After treatment, exercise performance in terms of cycling duration and workload were comparable between treatment arms (Figure 2). Quadriceps acidification during exercise was larger after KB suppletion compared to placebo (ΔpH: -0.2 [-0.3 - -0.1] vs -0.1 [-0.3 - -0.1] respectively; p=0.041) while quadriceps energy depletion during exercise was not altered by treatment (ΔPi/PCr 0.77 [0.55 – 2.51] vs 0.66 [0.46 – 0.81] respectively; p=0.087). Post-exercise mitochondrial oxidative function was similar between treatment arms (KB: PCr resynthesis rate 48 sec [25 – 59] versus placebo: 42 sec [36 – 63]; p=0.767). Conclusions Ketone body suppletion increased acidification and did not improve energy balance in skeletal muscle during exercise or mitochondrial function during recovery in patients with chronic HF. These results question the value of ketone bodies as treatment to boost muscular energy metabolism during exercise in HF.31P MRS Spectrum during exercise in HFExercise and energy parameters

Photosynthetic Electron Flows and Networks of Metabolite Trafficking to Sustain Metabolism in Photosynthetic Systems

Photosynthetic eukaryotes have metabolic pathways that occur in distinct subcellular compartments. However, because metabolites synthesized in one compartment, including fixed carbon compounds and reductant generated by photosynthetic electron flows, may be integral to processes in other compartments, the cells must efficiently move metabolites among the different compartments. This review examines the various photosynthetic electron flows used to generate ATP and fixed carbon and the trafficking of metabolites in the green alga Chlamydomomas reinhardtii; information on other algae and plants is provided to add depth and nuance to the discussion. We emphasized the trafficking of metabolites across the envelope membranes of the two energy powerhouse organelles of the cell, the chloroplast and mitochondrion, the nature and roles of the major mobile metabolites that move among these compartments, and the specific or presumed transporters involved in that trafficking. These transporters include sugar-phosphate (sugar-P)/inorganic phosphate (Pi) transporters and dicarboxylate transporters, although, in many cases, we know little about the substrate specificities of these transporters, how their activities are regulated/coordinated, compensatory responses among transporters when specific transporters are compromised, associations between transporters and other cellular proteins, and the possibilities for forming specific ‘megacomplexes’ involving interactions between enzymes of central metabolism with specific transport proteins. Finally, we discuss metabolite trafficking associated with specific biological processes that occur under various environmental conditions to help to maintain the cell’s fitness. These processes include C4 metabolism in plants and the carbon concentrating mechanism, photorespiration, and fermentation metabolism in algae.

Biomarker identification and risk assessment of cardiovascular disease based on untargeted metabolomics and machine learning

Cardiovascular disease (CVD) is the leading cause of mortality, disability, and healthcare costs, with a significant impact on the elderly and contributing to premature deaths across various age groups, including those below age 70. Despite decades of transformative discoveries and clinical efforts, the challenges of diagnosis, prevention, and treatment of CVD persist on a massive scale. This study aimed to unravel potential CVD-associated biomarkers and establish a machine learning model for the risk assessment of CVD. Untargeted metabolic assay with ultra-high performance liquid chromatography-tandem mass spectrometry and routine clinical biochemistry test were undertaken on the fasting venous blood specimens from 57 subjects. Four relevant clinical traits and 164 CVD-associated metabolites were identified, especially those related to glycerophospholipid metabolism and biosynthesis of unsaturated fatty acids. The machine learning model achieved from an integrated biomarker panel of palmitic amide, oleic acid, 138-pos (the 138th detected metabolomic feature in positive ion mode), phosphatidylcholine, linoleic acid, age, direct bilirubin, and inorganic phosphate, was able to improve the accuracy of CVD risk assessment up to a high satisfactory value of 0.91. The findings indicate that disorders in the metabolic processes of biological membranes and energy are significantly associated with increased risk of vascular damage in CVD patients. With machine learning methods, the pivotal metabolites and clinical biomarkers offer a promising potential for the efficient risk assessment and diagnosis of CVD.

Calcific aortic valve disease-associated long noncoding RNA H19 promotes the osteogenic transition of valvular interstitial cells via the JAG1/NOTCH1 axis

Abstract Background Calcific aortic valve disease (CAVD) is the most prevalent valvular heart disease causing tremendous suffering globally. The osteogenic differentiation of the valvular interstitial cells (VICs) is a key process in the pathogenesis of CAVD leading to calcification and stiffening. Here, we focus on the contribution of long noncoding RNA H19 in the osteogenic differentiation of VICs promoting CAVD. Methods and results A human lncRNA array performed in AVS patients with coronary artery disease (CAD) revealed the differential expression of lncRNA H19. For the experiments in this study, loss of function (LOF) was performed in primary VICs isolated from the aortic valves of patients with CAVD, and commercially-available VICs. Therefore, H19 expression was effectively downregulated via RNAi. Subsequent gene expression analysis via RT-qPCR revealed that the expression of calcification markers RUNX2 and BMP2, as well as the expression of the H19 downstream targets JAG1 and NOTCH1 were unchanged after the H19 knockdown alone. Then, the VICs were additionally treated with osteogenic medium (OM) and procalcifying medium (PCM) for 7 d to induce the calcification of the cells. In the OM, inorganic phosphate is generated in an alkaline phosphatase (ALPL)-dependent manner and integrated into newly formed hydroxyapatite crystals, thus promoting cellular calcification. PCM contains inorganic phosphate to form hydroxyapatite crystals and is therefore not ALPL-dependent. Gene expression analysis via RT-qPCR and protein analysis via immunofluorescence revealed that the calcification markers BMP2 and RUNX2 were upregulated after H19 knockdown and calcification induction. This indicates that H19 regulates the expression of calcification makers promoting cellular calcification. Furthermore, RT-qPCR and immunoblotting revealed the differential expression of several potential H19 downstream targets, namely JAG1, NOTCH1, and STAT3. The analysis showed that the potential downstream targets were upregulated after H19 knockdown and calcification treatment hinting at the involvement of the NOTCH1 or STAT3 pathway in the pathogenesis of CAVD. Moreover, an Alizarin Red S staining of calcified nodules revealed reduced calcification after H19 knockdown and calcification treatment for 21 d. This demonstrates that H19 also regulates a late-stage event in the cellular calcification of VICs. Conclusion Our study showed that H19 regulates calcification marker expression and the expression of potential downstream targets JAG1, NOTCH1, and STAT3 both in healthy and AVS patient VICs. This hints at the involvement of the H19/JAG1/NOTCH1 pathway in the calcification of VICs, which might play a critical role in the pathogenesis of CAVD.

Seasonal and long-term variations of nutrients in Liaodong Bay, China: Influencing factors and ecological effects

Nutrients are essential for marine primary productivity and have a critical role in maintaining the structure and function of marginal. Variations in nutrient levels in sea ecosystems can influence ecological disturbances significantly. The Liaodong Bay (LDB) is a semi-enclosed marginal sea in northern China. It has experienced severe eutrophication since the 1990s, leading to considerable environmental challenges. Understanding of seasonal and long-term nutrient dynamics in the LDB is limited. We examined seasonal datasets collected in May (spring), August (summer), November (autumn), and March (winter) of 2019, and analyzed long-term trends through historical records spanning multiple decades. Nutrients accumulated during autumn/winter but were depleted during spring/summer. A low concentration of dissolved inorganic phosphate led to an increased nitrogen ratio exceeding the Redfield ratio (>16) during winter, spring, and summer, driven by phytoplankton growth. In late-autumn, nutrient concentrations increased, with ratios approaching the Redfield ratio. Phosphorus limitation prevailed in spring, summer, and winter, while silicon limitation dominated in autumn. Dissolved inorganic nitrogen and nitrogen ratios in the LDB increased sharply since the 1980s, peaking before declining after 2013. Dissolved silica and silicon ratios decreased steadily, stabilizing in recent years. These trends imply a shift from nitrogen-to-phosphorus limitation, influenced by riverine inputs and atmospheric deposition. These nutrient fluctuations may have significant ecological effects, including dinoflagellate abundance, algal blooms, and jellyfish blooms. Our analyses highlight the complexity of nutrient dynamics and positive impact of local nutrient-reduction policies implemented in recent years in improving the environmental quality of the LDB.

Alleviating effect of whey protein supplementation on oxidative stress in hypothyroidism.

Hypothyroidism is one of the most prevalent thyroid pathologies, which causes oxidative stress by disrupting antioxidant mechanisms. In mammals, the thyroid glands regulate metabolism, development, and growth. Dysfunction of the thyroid gland can result in hypothyroidism, hyperthyroidism, thyroiditis, and thyroid cancer. Whey protein is a widely consumed protein supplement containing abundant sulphur-containing amino acids and bioactive peptides. Here, we analysed the effect of whey protein on oxidative stress in hypothyroidism. In vivo studies were conducted in two phases for 30 and 90 days, respectively. Hypothyroidism was induced in Wistar albino rats by administering 0.05% propylthiouracil (PTU) through drinking water. Five hypothyroid groups and the normal control group were maintained in the first 30 day phase of the study. Among these, one group served as the induced control group, three groups received whey protein at different concentrations (100, 300, and 500 mg per kg body weight), and the last group received L-thyroxine (2 μg per 100 g body weight) as a positive medication. The activities of antioxidant enzymes, such as superoxide dismutase, catalase, glutathione peroxidase, and glutathione-S-transferase, were analysed, and the levels of total antioxidants, glutathione, and malondialdehyde were determined. Ca2+ ATPase and Na+/K+ ATPase activities were detected by estimating the inorganic phosphate content. Histopathological analysis was carried out on the thyroid and liver tissues of all groups. Antioxidant activity was notably increased for higher doses of whey protein compared to that in the diseased control group (p < 0.05). From this initial study, the dose that achieved the desired therapeutic effect was 500 mg kg-1, which was considered for the next 90 day phase of the study. The 90 day phase of the study was conducted with five groups: normal, whey protein-supplemented, hypothyroid, whey protein-supplemented hypothyroid, and levothyroxine-supplemented hypothyroid. All the PTU-treated groups showed degenerative alterations in thyroid histology. Whey protein supplementation causes a considerable decrease in MDA levels with an increase in the major antioxidant enzyme and ATPase activities, with p < 0.05. As a nutritional supplement, whey protein, at a 500 mg kg-1 dose, effectively boosts antioxidant activity without causing any toxicological concerns in long-term use.

Antisalmonella Activities of Essential Oil of Psidium guajava Leaves: An In vitro and In vivo Study

Background: Life-threatening typhoidal salmonella infection is becoming more difficult to treat due to rising resistance to commonly used antibiotics. This resistance is aided by the biofilm-forming ability of the bacteria. This study investigated the in vitro and in vivo antisalmonella activities of essential oil of Psidium guajava leaves. Methods: Essential oil was extracted from the leaves of Psidium guajava with solvents. The sensitivity of Salmonella Typhi to the essential oil of Psidium guajava (EOPG) was assessed via the agar well diffusion method. Minimum inhibitory, bactericidal and biofilm-inhibitory concentrations (MIC, MBC and MBIC respectively) were measured using micro-broth dilution and crystal violet assay respectively. The effect of EOPG on the bacterial cell membrane was evaluated by measuring the efflux of potassium ions, inorganic phosphate and pyruvic acid. Bioautography and GC-MS were employed to identify the constituents of the active fraction of the EOPG. Effects of EOPG on the level of bacteremia and bone marrow infection in male Wistar rats were determined by plating caudal blood on salmonella-shigella agar. Selected serum cytokines were measured using ELISA kits. Effect on hepatic DNA was measured by comet assay while histological evaluation of the liver of infected rats was done by Hematoxylin and Eosin staining. Results: Essential oil of Psidium guajava leaves (EOPG) inhibited the growth of S. Typhi with a zone of inhibition of 13±0.2mm compared to 31±0.3mm recorded by ciprofloxacin. Minimum inhibitory, minimum bactericidal and minimum biofilm inhibitory concentrations were 25, &gt;50 and 12.5 mg/mL respectively. Exposure to EOPG caused efflux of potassium ions, inorganic phosphate and pyruvic acid in S. Typhi. Oral administration of 50 mg/mL of EOPG reduced bacterial load in the blood and bone marrow of S. Typhi-infected rats significantly (P&lt;0.05) when compared to untreated animals. Infection-induced reduction of serum IL-1β and rise in serum IFN-γ were ameliorated considerably in treated animals. The hepatic DNA of infected animals were protected from breakage in the group administered 50 mg/mL/day of EOPG compared with untreated, ciprofloxacin-treated as well as those administered 100 mg/mL/day of EOPG. Conclusion: EOPG has both in vitro and in vivo anti-salmonella activities, this could be exploited in developing new drug leads for treatment of typhoid fever

Study of Na+/K+-ATPase and Components of the Ca2+-transporting System in Myocardium under Experimental Prediabetes and Type 1 Diabetes in Rats

One of the complications of diabetes mellitus (DM) is diabetic cardiomyopathy (DCM), the molecular mechanisms of pathogenesis of which have not been fully studied. Previously, the involvement of Na+/K+-ATPase and components of the Ca2+ transport system in cardiomyocytes in the development of DCM was shown. The aim of the work was to study the expression and activity of Na+/K+-ATPase and Ca2+-ATPase (SERCA2) in the myocardium of male Wistar rats in a model of streptozotocin (STZ)-induced prediabetes and overt type 1 diabetes (T1DM). STZ was administered at once i. p. in dose of 30–35 mg/kg. Rats with glucose levels above 11 mM were considered diabetic (STZ-D1 group), and those with moderate hyperglycemia were considered prediabetic (STZ-preD1 group). The activity of Na+/K+-ATPase and Ca2+-ATPase was determined (by the rate of release of inorganic phosphate, Pi), and the expression of the genes α1- and α2-isoforms of Na+/K+-ATPase, SERCA2 and Kir6.1, Kv7.1 and Kv2.1 potassium channels. In the control (C) group, the activity of Mg2+-dependent ATPase (α1- and α2-isoforms of Na+/K+-ATPase), sensitive to 1 mM ouabain, was 6.03±0.6 mmol Pi/g/h. In the STZ-D1 and STZ-preD1 groups, Na+/K+-ATPase activity did not differ from group C. The level of gene expression of α1- and α2- subunits of Na+/K+-ATPase in the STZ-D1 group decreased by more than 45%, then both in the STZ-preD1 group increased by 64 and 81%, which may indicate a high sensitivity of expression to insulinopenia. The activity of Ca2+-ATPase and the expression of the SERCA2 gene did not differ between the groups – probably, the 4-week period after STZ administration is not sufficient for the development of Ca2+-ATPase deficiency in the rat heart. The level of expression of the genes of the potassium channel subtypes Kv2.1, Kir6.1 and Kv7.1 increased in the STZ-preD1 group, which may indicate a certain contribution of the studied potassium channel subtypes to the adaptation mechanism to moderate hyperglycemia.

THE EFFECT OF SODIUM DEOXYCHOLATE AND TWЕЕN-20 ON THE ACTIVITY AND PROPERTIES OF NA+/K+-ATPase IN THE MIXED MEMBRANE FRACTION OF THE CEREBRAL CORTEX OF RATS

Interoduction. The present work extends the understanding of the activity of ouabain-sensitive (α2 and α3) and ouabain-resistant (α1) Na+/K+-ATPase isoforms in the mixed membrane fraction of rat cerebral cortex in the presence of various detergents. The aim of the study: to determine the activity of ouabain-sensitive (α2 and α3) and ouabain-resistant (α1) Na+/K+-ATPase isoforms by changing the concentration of Mg+2 ions in the incubation medium and using the detergents sodium deoxycholate and Tween-20. Material and methods. To determine Na+/K+-ATPase activity, we used the method of A. Kazennova et al. The reaction was triggered by adding ho-mogenate of cerebral cortex incubated with detergents; the samples were incubated for 30 minutes in a water bath at 370 C. The activity of ouabain-sensitive isoforms was determined by adding 200 μmol of ouabain to the incubation mixture. The activity of ouabain-sensitive isoforms was deter-mined by adding 200 μmol ouabain to the incubation mixture, and the activity of ouabain-resistant isoforms was determined as the difference between the total Na+/K+-ATPase activity and the activity of ouabain-sensitive isoforms. ATPase activity was determined by inorganic phosphate (Pi) increment as the difference between total ATPase activity, magnesium ATPase activity, in reaction with ammonium molybdate and tin chloride in the presence of ascorbic acid as a reducing agent. Results. At optimal concentrations of detergents Dox-Na (1.25 mg/mL) and Tween-20 (6.5 mg/mL), both ouabain-sensitive and ouabain-resistant Na+/K+-ATPase isoforms are characterized by normal activity dynamics from the concentration of Mg2+ ions. Consequently, the use of detergents at given concentrations does not change the ability of enzymes to conformational rearrangements during the reaction cycle. It was found that both used detergents allow to reveal a significant percentage of latent activity of ouabain-sensitive (α2 and α3) and ouabain-resistant (α1) Na+/K+-ATPase isoforms in the mixed mebran fraction of the cerebral cortex of rats. Conclusion. The study of Mg2+-dependent properties revealed a similar character of the curves of dependence of enzyme activity on the concentra-tion of Mg2+ in the incubation medium for all Na+/K+-ATPase isoforms studied

Selection and Effect of Plant Growth-Promoting Bacteria on Pine Seedlings (Pinus montezumae and Pinus patula).

Forest cover is deteriorating rapidly due to anthropogenic causes, making its restoration urgent. Plant growth-promoting bacteria (PGPB) could offer a viable solution to ensure successful reforestation efforts. This study aimed to select bacterial strains with mechanisms that promote plant growth and enhance seedling development. The bacterial strains used in this study were isolated from the rhizosphere and endophyte regions of Pinus montezumae Lamb. and Pinus patula Schl. et Cham., two Mexican conifer species commonly used for reforestation purposes. Sixteen bacterial strains were selected for their ability to produce auxins, chitinase, and siderophores, perform nitrogen fixation, and solubilize inorganic phosphates; they also harbored genes encoding antimicrobial production and ACC deaminase. The adhesion to seeds, germination rate, and seedling response of P. montezumae and P. patula were performed following inoculation with 10 bacterial strains exhibiting high plant growth-promoting potential. Some strains demonstrated the capacity to enhance seedling growth. The selected strains were taxonomically characterized and belonged to the genus Serratia, Buttiauxella, and Bacillus. These strains exhibited at least two mechanisms of action, including the production of indole-3-acetic acid, biological nitrogen fixation, and phosphate solubilization, and could serve as potential alternatives for the reforestation of affected areas.

Effects of inorganic phosphate on stem cells isolated from human exfoliated deciduous teeth

Calcium phosphate-based materials (CaP) are introduced as potential dental pulp capping materials for deciduous teeth. The present study investigated the influence of inorganic phosphate (Pi) on regulating stem cells isolated from human exfoliated deciduous teeth (SHED). SHEDs were treated with Pi. Cell cycle progression and apoptosis were examined using flow cytometry analysis. Osteo/odontogenic and adipogenic differentiation were analyzed using alizarin red S and oil red O staining, respectively. The mRNA expression profile was investigated using a high-throughput RNA sequencing technique. Pi increased the late apoptotic cell population while cell cycle progression was not altered. Pi upregulated osteo/odontoblastic gene expression and enhanced calcium deposition. Pi-induced mineralization was reversed by pretreatment of cells with Foscarnet, or p38 inhibitor. Pi treatment inhibited adipogenic differentiation as determined by decreased PPARγ expression and reduced intracellular lipid accumulation. Bioinformatic analysis of gene expression profiles demonstrated several involved pathways, including PI3K/AKT, MAPK, EGFR, and VEGF signaling. In conclusion, Pi enhanced osteo/odontogenic but inhibited adipogenic differentiation in SHED.

Influence of N- and/or P-restriction on bone metabolism in young goats.

Ruminants can recycle nitrogen (N) and phosphorus (P), which are essential for vital body processes. Reduced N- and P-intake in ruminants is desirable for economic and ecologic reasons. Simultaneous modulation of mineral homoeostasis and bone metabolism occurs in young goats. This study aimed to investigate potential effects of dietary N- and/or P-restriction on molecular changes in bone metabolism. The twenty-eight young male goats were fed a control diet, an N-reduced diet, a P-reduced diet or a combined N- and P-reduced diet for 6-8 weeks. The N-restricted goats had lower plasma Ca concentration and higher plasma osteocalcin (OC) and CrossLaps concentrations. The P-restricted goats had reduced plasma inorganic phosphate (Pi) concentrations and increased plasma Ca concentrations. Due to the initiation of a signalling pathway that inhibits the fibroblast growth factor 23 (FGF23) expression, this was lower with P-restriction. Consequently, lower Pi concentrations were the main factor influencing the reduction in FGF23. The changes in mineral homoeostasis associated with P-restriction led to a reduction in OC, bone mineral content and mineral density. Simultaneously, bone resorption potentially increased with P-restriction as indicated by an increased receptor activator of NF-κB ligand/osteoprotegerin (OPG) ratio and an increase in OPG mRNA expression. Additionally, the increased mRNA expression of the calcitonin receptor during P-restriction points to a higher number of osteoclasts. This study demonstrates an impairment of bone remodelling processes in young goats by N- or P-restriction. With P-restriction, bone mineralisation rate was potentially reduced and bone quality impaired, while with N-restriction, bone remodelling increased.

FUNCTIONAL STATE OF RENAL PARENCHYMA IN CHILDREN WITH DYSMETABOLIC NEPHROPATHY

Abstract. Metabolic nephropathy in children is a relevant issue in our time, as the prevalence of this disease is increasing. Negative consequences of metabolic nephropathy include a gradual deterioration of kidney function. A significant aspect is the fact that metabolic nephropathy can lead to the development of chronic kidney disease in children. Chronicity requires continuous medical monitoring and treatment to support kidney function and prevent further complications, such as renal insufficiency and other metabolic disorders. There is no doubt that one of the leading pathogenetic factors in kidney dysfunction is hypoxia. It can be caused by both hemodynamic disturbances associated with renal pathology and tissue respiration disorders in congenital dysplasia of the kidney's connective tissue, which arises in the embryo under the influence of epigenetic factors in utero and is further exacerbated by various epigenetic factors in postnatal life. Purpose of the work to investigate the functional state of kidney parenchyma in children with dysmetabolic nephropathy. Materials and methods. Two groups of children were examined: those with a complicated course of dysmetabolic nephropathy, a history of inflammatory episodes of the urinary system organs (Group I - UN, 52 children), and dysmetabolic nephropathy with persistent crystalluria (Group II - DN, 56 children). A control group consisted of 65 healthy children. Tubular reabsorption, as a partial function of the proximal segment of the nephrons, was assessed based on urinolysis test data, specifically the levels of excretion of inorganic phosphates, proteinuria, amino acids, reduced sugars (maltose, sucrose, fructose by Benedict's test), glucose (by Gaines's test), and calcium (by Sulcovitch's test). The level of creatinine and glycosaminoglycan (GAG) excretion in daily urine in children with dysmetabolic nephropathy was determined and compared with data from healthy children in the control group. Research results. In children from both observation groups, a significantly high frequency of hyperphosphaturia (94.23% and 96.42%), calciuria (94.23% and 89.28%), glucosuria (78.85% and 73.21%), increased excretion of amino acids in the urine (40.38% and 37.5%), microproteinuria (32.69% and 28.57%), and increased excretion of reduced sugars (28.85% and 26.79%) were observed. The daily excretion of creatinine, glycosaminoglycans, and oxypyrrolidine in the urine of children with dysmetabolic nephropathy indicates a significantly reduced level of creatinine in the daily urine in the majority of children in Group I (0.56±0.19 g/L, 80.77% of those examined) and more than half of the children in Group II (0.83±0.08 g/L, 57.14% of those examined), compared to the data from healthy children in the control group (1.25±0.75 g/L, 0.0%). Conclusions. The analysis of the functional state of the kidney tissue in oxalate dysmetabolic nephropathy in children allows us to testify to the presence of tubular and glomerular partial renal tissue failure. Significant decreases in creatinine excretion and increased excretion of glycosoaminoglycans in the urine and significantly higher levels of oxyproline in the urine indicate the presence of glomerular type partial renal failure in oxalate dysmetabolic nephropathy in children and the presence of undifferentiated dysplasia of the renal connective tissue with the onset of its sclerosis with subsequent transition to interstitial nephritis. The presence of these changes in the vast majority of children with complicated course of oxalate dysmetabolic nephropathy in the period of clinical and laboratory remission of the inflammatory process indicates the priority of renal connective tissue dysplasia and paucity of renal failure in the pathogenesis of dysmetabolic nephropathy and its severity in children. Indicators of oxyproline creatinine, glycosoaminoglycans and oxyproline excretion can be used as epigenetic markers of susceptibility to dysmetabolic nephropathy in general and its more severe course in particular. Keywords: dysmetabolic nephropathy, functional state, kidney parenchyma, nephron.

The role of proton excreted by Advenella kashmirensis DF12 during ammonium assimilation in phosphate solubilization.

Phosphate-solubilizing bacteria (PSB) can solubilize soil fixed phosphorus (P) to plant available forms. In previous studies, the mechanisms of inorganic phosphate solubilization by PSB mostly focused on the acidolysis of organic acids. Here we screened a highly efficient PSB, Advenella kashmirensis DF12, with the maximum P solubilization of 590 mg L- 1 at 6 days. In addition to its P solubilizing ability, DF12 also showed a tolerance to pH from 5 to 10 and a nitrogen fixation potential. The multiple functions of DF12 and its wide adaptability to various environmental conditions make it a promising biofertilizer candidate. The combined analysis of extracellular metabolites and intracellular metabolome data revealed that the production of organic acid (mainly gluconic acid) is not the only mechanism of P solubilized by DF12, the solubilized P content was not correlated with the gluconic acid concentration but was in a highly significant positive correlation with proton concentration, extrusion of proton during NH4+ assimilation plays a key role in phosphate solubilization. Moreover, the contribution of NH4+ assimilation to phosphorus solubilization is generally present in PSB. Therefore, we proposed that applying ammonium fertilizer in P-deficient soil is more appropriate, it can not only supplement nitrogen fertilizer, but also enhance P use efficiency, which contributes to worldwide fertilizer use reduction and efficiency improvement.

Within Thermal Scales: The Kinetic and Energetic Pull of Chemical Entropy.

Biological systems are fundamentally containers of thermally fluctuating atoms that through unknown mechanisms are structurally layered across many thermal scales from atoms to amino acids to primary, secondary, and tertiary structures to functional proteins to functional macromolecular assemblies and up. Understanding how the irreversible kinetics (i.e., the arrow of time) of biological systems emerge from the equilibrium kinetics of constituent structures defined on smaller thermal scales is central to describing biological function. Muscle's irreversible power stroke - with its mechanochemistry defined on both the thermal scale of muscle and the thermal scale of myosin motors - provides a clear solution to this problem. Individual myosin motors function as reversible force-generating switches induced by actin binding and gated by the release of inorganic phosphate, P i . As shown in a companion article, when N individual switches thermally scale up to an ensemble of N switches in muscle, the entropy of a binary system of switches is created. We have shown in muscle that a change in state of this binary system of switches entropically drives actin-myosin binding (the switch) and muscle's irreversible power stroke, and that this simple two-state model accurately accounts for most key aspects of muscle contraction. Extending this observation beyond muscle, here I show that the chemical kinetics of an ensemble of N molecules differs fundamentally from a conventional chemical analysis of N individual molecules, describing irreversible chemical reactions as being pulled into the future by the a priori defined entropy of a binary system rather than being pushed forward by the physical occupancy of chemical states (e.g., mass action).

Impact of humic acid on iron (oxyhydr)oxide transport in the presence of phosphate in saturated porous media

The subsurface flow of particular phosphate (P) has been recently regarded as a vital P transport path. Humic acid (HA) and P usually coexist in the natural environment and show a strong affinity to iron (Fe) (oxyhydr)oxide. The impact of P and HA on Fe (oxyhydr)oxide stability and transport is critical for evaluating the vertical transport of particular P and biogeochemical processes of Fe and P. This study investigated the effect of inorganic (IP) and organic (OP) phosphate on the stability and transport of ferrihydrite and goethite with HA through stability tests and column experiments. The adsorption of IP or OP on Fe (oxyhydr)oxide enhanced the stability and transport of Fe (oxyhydr)oxide, and OP showed a stronger enhancement than IP due to its stronger binding capacity and more negative surface. Compared with ferrihydrite, goethite had fewer adsorption sites for IP or OP and showed strong stability and transport at low IP (50 μM) or OP (10 μM) concentration. HA decreased IP or OP adsorption on Fe (oxyhydr)oxide through competition adsorption and electrostatic repulsion. The formed ternary phosphate-Fe (oxyhydr)oxide-HA complex showed a more negative surface and strong stability and transport. Our findings provide direct insights into the distinct role of IP and OP on Fe (oxyhydr)oxide stability and transport in the presence of HA, which provides essential information for evaluating the transport of particular Fe (oxyhydr)oxide-facilitated P in soils and subsurface environments rich in iron, phosphate, and dissolved carbon.

Exploring the antimicrobial activity of hydrothermally synthesized copper pyrophosphate nanoflakes

In recent years, infections and the escalating resistance to antimicrobial drugs have emerged as significant health concerns. Due to their remarkable effectiveness and minimal potential for bacteria to develop resistance, copper-based nanomaterials are being considered as prospective alternatives to conventional antibiotics. In this study, copper pyrophosphate nanoflakes were synthesized using a simple hydrothermal technique with an inorganic phosphate source. These nanoflakes, characterized by a high aspect ratio, exert a substantial impact on bacterial cell walls, effectively eliminating microbial pathogens. X-ray diffraction (XRD) analysis confirmed the monoclinic phase of the copper pyrophosphate nanomaterial, while the band gap energy of 2.7 eV was estimated from the Tauc plot. Additionally, the antimicrobial efficacy of Cu2P2O7 was evaluated against various gram-negative, gram-positive, and fungal pathogens at different concentrations. Notably, all tested bacterial strains exhibited moderate antimicrobial effects at concentrations of 5 mg/mL. For instance, S. aureus and E. coli displayed a 13 mm zone of inhibition, demonstrating excellent activity and lower cytotoxicity. These findings underscore the potential of Cu2P2O7 as a promising candidate for the development of novel drugs targeting pathogenic bacteria affecting human health.