Role Of Phosphorus Research Articles

A Chemist's Perspective on the Role of Phosphorus at the Origins of Life.

The central role that phosphates play in biological systems, suggests they also played an important role in the emergence of life on Earth. In recent years, numerous important advances have been made towards understanding the influence that phosphates may have had on prebiotic chemistry, and here, we highlight two important aspects of prebiotic phosphate chemistry. Firstly, we discuss prebiotic phosphorylation reactions; we specifically contrast aqueous electrophilic phosphorylation, and aqueous nucleophilic phosphorylation strategies, with dry-state phosphorylations that are mediated by dissociative phosphoryl-transfer. Secondly, we discuss the non-structural roles that phosphates can play in prebiotic chemistry. Here, we focus on the mechanisms by which phosphate has guided prebiotic reactivity through catalysis or buffering effects, to facilitating selective transformations in neutral water. Several prebiotic routes towards the synthesis of nucleotides, amino acids, and core metabolites, that have been facilitated or controlled by phosphate acting as a general acid–base catalyst, pH buffer, or a chemical buffer, are outlined. These facile and subtle mechanisms for incorporation and exploitation of phosphates to orchestrate selective, robust prebiotic chemistry, coupled with the central and universally conserved roles of phosphates in biochemistry, provide an increasingly clear message that understanding phosphate chemistry will be a key element in elucidating the origins of life on Earth.

First-principles study of phosphorus embrittlement in austenitic steels with κ-carbide precipitates

Ab initio density functional theory calculations were performed to study the effect of phosphorus on the structural, electronic, and magnetic properties of bulk, surface, and interface of κ-carbide (Fe3AlC) and fcc Fe. The aim was to shed light on the role of phosphorus in austenitic steels with κ-carbide particles, where its presence promotes both intergranular and transgranular embrittlement. The embrittling potency energy calculated as a difference between phosphorus binding energies at the Fe3AlC or fcc Fe surfaces and at Fe3AlC/Fe interface, indicates that phosphorus promotes embrittling behavior. Phosphorus at the interface has negative segregation energy which strongly depends on the phosphorus location as well as its concentration. The calculated cleavage energy decreases sharply for κ-carbide with substituted phosphorus as well as for the interface with segregated phosphorus; both contribute to the embrittlement. These results elucidate the microscopic reasons why phosphorus favors crack nucleation in κ-carbide, and why a crack propagates along the boundary between κ-carbide and austenite.

Methodological aspects of determining phosphorus digestibility in swine: A review.

The role of phosphorus (P) in swine nutrition has been taken on new significance in recent years. Methods to determine the available phosphorus (AP) content of swine feeds include relative bioavailability (RBV), apparent total tract digestibility (ATTD), standardized total tract digestibility (STTD), and true total tract digestibility (TTTD). The RBV of P is determined by measuring bone ash or bone P, whereas the ATTD of P is determined by calculating the difference between P intake and P excretion in feces. Recent research has shown that the use of ATTD of P underestimates the AP due to the existence of endogenous P in feces and digesta. The STTD can be calculated from ATTD by taking basal endogenous phosphorus losses (EPL) into consideration. The basal EPL in pigs can be measured by feeding a P-free diet. Values for STTD of P are believed to be additive in mixed diets but not for ATTD of P. The regression method is a common approach to determine total EPL and TTTD of P, which measures the linear relationship between fecal P excretion and the dietary intake of total P. In addition, in vitro methods such as the bionic enzymatic method are being increasingly utilized because they can be done quickly and simply. Several dietary factors such as P and Ca concentrations, phytate, Ca to P ratio and vitamin D may affect AP. This review summarizes the evolution of methods to measure AP and factors that can affect AP, which may provide information to formulate swine diet more accurately. Moreover, the knowledge about AP may help to reduce the P waste in swine production and thus decrease its impact on the environment.

Constrains, Production Systems and Roles of Phosphorus in Rice Production in Tanzania

Constrains, Production Systems and Roles of Phosphorus in Rice Production in Tanzania

The role of phosphorus in precipitation behavior and its effect on the creep properties of alumina-forming austenitic heat-resistant steels

The precipitation behavior and creep properties of lower phosphorus (P) alumina-forming austenitic (AFALP) heat-resistant steel were investigated and compared to those of AFA. The creep rupture time and hardness of the investigated steels were improved with the decrease of the P content. The TEM and EELS analyses confirmed an enhanced P concentration in the M23C6 precipitates along the grain boundaries. The P promoted the precipitation of M23C6 and also suppressed the precipitation of secondary NbC in the earlier stage of aging. The creep rupture time of AFA became shorter compared to AFALP due to the reduction in the fraction of secondary NbC which acts as a dominant strengthening phase during creep. The suppression of secondary NbC precipitation by P increased the Nb content in the austenite matrix and accelerated the precipitation of the Laves phase in the intermediate stage. However, the difference in Vickers hardness caused by Laves phase was not large in both alloys because the volume fraction of Laves phase strongly depended on the nominal content of Mo rather than Nb. The Vickers hardness at the earlier stage is determined by the precipitation of secondary NbC and the difference of the hardness maintained at the final stage. Thus, it is found that P degrades the creep rupture time and P is a detrimental element in terms of creep and precipitation hardening in AFA steels.

Enhancing phosphorus uptake efficiency through QTL-based selection for root system architecture in maize

Root system architecture (RSA) plays an important role in phosphorus (P) acquisition, but enhancing P use efficiency (PUE) in maize via genetic manipulation of RSA has not yet been reported. Here, using a maize recombinant inbred line (RIL) population, we investigated the genetic relationships between PUE and RSA, and developed P-efficient lines by selection of quantitative trait loci (QTLs) that coincide for both traits. In low-P (LP) fields, P uptake efficiency (PupE) was more closely correlated with PUE (r = 0.48–0.54), and RSA in hydroponics was significantly related to PupE (r = 0.25–0.30) but not to P utilization efficiency (PutE). QTL analysis detected a chromosome region where two QTLs for PUE, three for PupE and three for RSA were assigned into two QTL clusters, Cl-bin3.04a and Cl-bin3.04b. These QTLs had favorable effects from alleles derived from the large-rooted and high-PupE parent. Marker-assisted selection (MAS) identified nine advanced backcross-derived lines carrying Cl-bin3.04a or Cl-bin3.04b that displayed mean increases of 22%–26% in PUE in LP fields. Furthermore, a line L224 pyramiding Cl-bin3.04a and Cl-bin3.04b showed enhanced PupE, relying mainly on changes in root morphology, rather than root physiology, under both hydroponic and field conditions. These results highlight the physiological and genetic contributions of RSA to maize PupE, and provide a successful study case of developing P-efficient crops through QTL-based selection.

The role of phosphorus in the metabolism of arsenate by a freshwater green alga, Chlorella vulgaris

A freshwater microalga, Chlorella vulgaris, was grown in the presence of varying phosphate concentrations (<10–500μg/L P) and environmentally realistic concentrations of arsenate (As(V)) (5–50μg/L As). Arsenic speciation in the culture medium and total cellular arsenic were measured using AEC-ICP-MS and ICP-DRC-MS, respectively, to determine arsenic biotransformation and uptake in the various phosphorus scenarios. At high phosphate concentration in the culture medium, >100μg/L P, the uptake and biotransformation of As(V) was minimal and dimethylarsonate (DMAs(V)) was the dominant metabolite excreted by C. vulgaris, albeit at relatively low concentrations. At common environmental P concentrations, 0–50μg/L P, the uptake and biotransformation of As(V) increased. At these higher As-uptake levels, arsenite (As(III)) was the predominant metabolite excreted from the cell. The concentrations of As(III) in these low P conditions were much higher than the concentrations of methylated arsenicals observed at the various P concentrations studied. The switchover threshold between the (small) methylation and (large) reduction of As(V) occurred around a cellular As concentration of 1fg/cell. The observed nearly quantitative conversion of As(V) to As(III) under low phosphate conditions indicates the importance of As(V) bio-reduction at common freshwater P concentrations. These findings on the influence of phosphorus on arsenic uptake, accumulation and excretion are discussed in relation to previously published research. The impact that the two scenarios of As(V) metabolism, As(III) excretion at high As(V)-uptake and methylarsenical excretion at low As(V)-uptake, have on freshwater arsenic speciation is discussed.

The effect of soil moisture extremes on the pathways and forms of phosphorus lost in runoff from two contrasting soil types

Soil moisture and Olsen P concentrations play an important role in phosphorus (P) losses in runoff. Under moisture-rich anaerobic conditions, the reduction of Fe-oxides dissolves P from the soil into solution that may be available for loss by transport processes. Under very dry conditions, soil hydrophobicity induced by soil organic C can exacerbate infiltration-excess surface flow and soil erosion. Our hypotheses were as follows: (1) rainfall applied to a dry soil would cause greater particulate P losses in surface runoff due to hydrophobicity; (2) P losses from a wet soil would be dominated by drainage and filtered P; and (3) both runoff processes would result in environmentally unacceptable P losses at agronomically productive Olsen P concentrations depending on the sorption capacity (anion storage capacity; ASC) of the soil. Superphosphate was added to a Brown and Organic soil (Olsen P initially 7 and 13mgL–1 respectively) to create a range of Olsen P concentrations. Soils were placed in boxes, soil moisture adjusted (&lt;10% or 90% available water holding capacity) and artificial rainfall applied at a rate equivalent to a storm event (5-year return interval; 30–35mmh–1) and surface runoff and drainage collected. Surface runoff was measured as infiltration-excess surface flow from dry Organic soil (water drop penetration time &gt;3600s), and as saturation-excess surface flow from the wet Brown soil (water drop penetration time &lt;5s). Total P (TP) concentrations in surface flow from both soils increased linearly with Olsen P concentration. Compared with dry Organic soil, the wet Brown soil lost a greater proportion of TP as particulate via surface runoff. However, due to the high hydraulic conductivity and low ASC, the most important pathway for the Organic soil, wet or dry, was filtered P loss in drainage. These data can be used to more effectively target strategies to mitigate P losses.

Phosphate: from stardust to eukaryotic cell cycle control.

Phosphorus is a pivotal element in all biochemical systems: it serves to store metabolic energy as ATP, it forms the backbone of genetic material such as RNA and DNA, and it separates cells from the environment as phospholipids. In addition to this "big hits", phosphorus has recently been shown to play an important role in other important processes such as cell cycle regulation. In the present review, we briefly summarize the biological processes in which phosphorus is involved in the yeast Saccharomyces cerevisiae before discussing our latest findings on the role of this element in the regulation of DNA replication in this eukaryotic model organism. We describe both the role of phosphorus in the regulation of G1 progression by means of the Cyclin Dependent Kinase (CDK) Pho85 and the stabilization of the cyclin Cln3, as well as the role of other molecule composed of phosphorus-the polyphosphate-in cell cycle progression, dNTP synthesis, and genome stability. Given the eminent role played by phosphorus in life, we outline the future of phosphorus in the context of one of the main challenges in human health: cancer treatment. [Int Microbiol 19(3):133-141 (2016)].

Effect of phosphorus addition on total and alkaline phosphomonoesterase-harboring bacterial populations in ryegrass rhizosphere microsites

Rhizobacterial communities may play a crucial role in phosphorus (P) nutrition of plants. However, our knowledge of how P fertilization modulates rhizobacterial communities in crops and pastures is still poor. Here, we investigated the effect of P addition (phosphate [PHO] and phytate [PHY]) on the composition of total bacterial communities and alkaline phosphomonoesterases (APase)-harboring bacterial populations in the rhizosphere microsites (root tip [RT] and mature zone [MZ]) of L. perenne. Sizes and diversities of bacterial communities were studied by 454-pyrosequencing of 16S rRNA genes, denaturing gradient gel electrophoresis (DGGE) and quantitative PCR (qPCR). Our results suggested that phosphorus addition induces significant changes in the rhizobacterial community composition. Despite that pyrosequence analysis showed that members of the Proteobacteria, Actinobacteria, Chloroflexi, and Acidobacteria were the dominant phyla in all sampled rhizosphere microsites, differences in the relative abundances of some bacterial genera were detected (e.g., Arthrobacter and Acidothermus). Greater richness in rhizosphere microsites of plants supplied with PHY compared with PHO were revealed. With respect to APase-harboring bacterial populations, DGGE (phoD gene) showed significant differences between microsites supplied with PHO, PHY and controls. qPCR (16S rRNA genes, phoD and phoX) showed significantly greater abundances of bacteria and APase genes in RT than in MZ microsites. This study contributes to our understanding of the effect P fertilization on rhizobacterial community compositions of pastures grown in Chilean Andisols.

SP327THE ROLE OF PHOSPHORUS, PTH, FGF-23, KLOTHO AND VITAMIN D ON HEMOGLOBIN LEVELS OF PATIENTS WITH CKD

SP327THE ROLE OF PHOSPHORUS, PTH, FGF-23, KLOTHO AND VITAMIN D ON HEMOGLOBIN LEVELS OF PATIENTS WITH CKD

Роль атомов фосфора и серы в реализации радиационного повреждения нуклеиновых кислот и белков

Роль атомов фосфора и серы в реализации радиационного повреждения нуклеиновых кислот и белков

The role of phosphorus, magnesium and potassium availability in soil fungal exploration of mineral nutrient sources in Norway spruce forests.

We investigated fungal growth and community composition in buried meshbags, amended with apatite, biotite or hornblende, in Norway spruce (Picea abies) forests of varying nutrient status. Norway spruce needles and soil collected from forests overlying serpentinite had low levels of potassium and phosphorus, those from granite had low levels of magnesium, whereas those from amphibolite had comparably high levels of these nutrients. We assayed the fungal colonization of meshbags by measuring ergosterol content and fungal community with 454 sequencing of the internal transcribed spacer region. In addition, we measured fine root density. Fungal biomass was increased by apatite amendment across all plots and particularly on the K- and P-deficient serpentinite plots, whereas hornblende and biotite had no effect on fungal biomass on any plots. Fungal community (total fungal and ectomycorrhizal) composition was affected strongly by sampling location and soil depth, whereas mineral amendments had no effect on community composition. Fine root biomass was significantly correlated with fungal biomass. Ectomycorrhizal communities may respond to increased host-tree phosphorus demand by increased colonization of phosphorus-containing minerals, but this does not appear to translate to a shift in ectomycorrhizal community composition. This growth response to nutrient demand does not appear to exist for potassium or magnesium limitation.

The role of phosphorus in a newly developed Ni-Fe-Cr-based wrought superalloy

The influence of phosphorus on the microstructures and mechanical properties of a newly developed Ni-Fe-Cr-based wrought superalloy (named as HT700 alloy) for ultra-supercritical power plant applications beyond 700°C was investigated. Results showed that adding phosphorus significantly prolonged the creep rupture life but had little influence on the yield strength of HT700 alloy when phosphorus content ranged from 0.002 to 0.027wt%. Meanwhile, intergranular failure mode dominated in all creep ruptured samples while transgranular failure was the main feature in the tensile tested samples. The effects of adding phosphorus on the nucleation and growth behavior of intergranular M23C6 carbides were found to be the main mechanism responsible for the difference.

Interaction of alkaline phosphatase with minerals and sediments: Activities, kinetics and hydrolysis of organic phosphorus

Abstract Alkaline phosphatase (APase) plays an important role in phosphorus (P) cycling in water and sediments of lakes. Interaction of APase with minerals including goethite and montmorillonite, and sediments from Lake Tai (Ch: Taihu ) and Lake Dianchi were investigated. Degradation and bioavailability of organic P (P o ) in sediments were further investigated by APase hydrolysis and solution 31 P-nuclear magnetic resonance (NMR) spectroscopy. Little APase is adsorbed by sediments, but APase could be strongly adsorbed by goethite and montmorillonite. Some adsorptive sites could be occupied by organic matter or ions in sediments from lakes. Activities of APase immobilized by sediments could be reduced to 1.3% to 5.3% of that of free APase. However, APase immobilized by goethite and montmorillonite could retain 27.3% and 21.6% of the activity of free APase. Thus, the majority of APase is likely dissolved in overlying water or loosely adsorbed by sediments in lakes. Enzymatic hydrolysis and liberation of orthophosphate from suspensions of sediments were 0.26–4.25 mg kg −1 that was readily bioavailable to algae or other organisms. After APase hydrolysis, 31 P NMR analysis showed that no detectable changes in P o or condensed P in sediments extracted by NaOH–EDTA. Thus, P o immobilized in sediments couldn’t be directly hydrolyzed by APase, but more P o immobilized in the sediments could be hydrolyzed by APase when they were released into the overlying water under appropriate conditions. Treatments, such as additions of Al hydroxides dosing, would not adsorb or immobilized P, but also immobilized phosphatase, thus decreasing activity of phosphatase and bioavailability of P o in a eutrophic lake.

Carbon cost of plant nitrogen acquisition: global carbon cycle impact from an improved plant nitrogen cycle in theCommunity Land Model.

Plants typically expend a significant portion of their available carbon (C) on nutrient acquisition - C that could otherwise support growth. However, given that most global terrestrial biosphere models (TBMs) do not include the C cost of nutrient acquisition, these models fail to represent current and future constraints to the land C sink. Here, we integrated a plant productivity-optimized nutrient acquisition model - the Fixation and Uptake of Nitrogen Model - into one of the most widely used TBMs, the Community Land Model. Global plant nitrogen (N) uptake is dynamically simulated in the coupled model based on the C costs of N acquisition from mycorrhizal roots, nonmycorrhizal roots,N-fixing microbes, and retranslocation (from senescing leaves). We find that at the global scale, plants spend 2.4Pg C yr(-1) to acquire 1.0 Pg Nyr(-1) , and that the C cost of N acquisition leads to a downregulation of global net primary production (NPP) by 13%. Mycorrhizal uptake represented the dominant pathway by which N is acquired, accounting for ~66% of the N uptake by plants. Notably, roots associating with arbuscular mycorrhizal (AM) fungi - generally considered for their role in phosphorus (P) acquisition - are estimated to be the primary source of global plant N uptake owing to the dominance of AM-associated plants in mid- and low-latitude biomes. Overall, our coupled model improves the representations of NPP downregulation globally and generates spatially explicit patterns of belowground C allocation, soil N uptake, and N retranslocation at the global scale. Such model improvements are critical for predicting how plant responses to altered N availability (owing to N deposition, rising atmospheric CO2 , and warming temperatures) may impact the land C sink.

A Review of Phosphide‐Based Materials for Electrocatalytic Hydrogen Evolution

Hydrogen evolution by means of electrocatalytic water‐splitting is pivotal for efficient and economical production of hydrogen, which relies on the development of inexpensive, highly active catalysts. In addition to sulfides, the search for non‐noble metal catalysts has been mainly directed at phosphides due to the superb activity of phosphides for hydrogen evolution reaction (HER) and their low‐cost considering the abundance of the non‐noble constituents of phosphides. Here, recent research focusing on phosphides is summarized based on their synthetic methodology. A comparative study of the catalytic activity of different phosphides towards HER is then conducted. The catalytic activity is evaluated by overpotentials at fixed current density, Tafel slope, turnover frequency, and the Gibbs free energy of hydrogen adsorption. Based on the methods discussed, perspectives for the various methods of phosphides synthesis are given, and the origins of the high activity and the role of phosphorus on the improved activity towards HER are discussed.

Monitoring studies should consider temporal variability to reveal relations between cyanobacterial abundance and environmental variables.

One of the main goals of monitoring cyanobacteria blooms in aquatic environments is to reveal the relationship between cyanobacterial abundance and environmental variables. Studies typically correlate data that were simultaneously sampled. However, samplings occur sparsely over time and may not reveal the short-term responses of cyanobacterial abundance to environmental changes. In this study, we tested the hypothesis that stronger cyanobacteria x environment relationships in monitoring are found when the temporal variability of sampling points is incorporated in the statistical analyses. To this end, we investigated relationships between cyanobacteria and seven environmental variables that were sampled twice yearly for three years across 11 reservoirs, and data from an intensive monitoring in one of these reservoirs. Poor correlations were obtained when correlating data simultaneously sampled. In fact, the 'highly recurrent' role of phosphorus in cyanobacteria blooms is not properly observed in all sampling periods. On the other hand, the strongest correlation values for the total phosphorus x cyanobacteria relationship were observed when we used the variation of sampling points. We have also shown that environment variables better explain cyanobacteria when a time lag is considered. We conclude that, in cyanobacteria monitoring, the best approach to reveal determinants of cyanobacteria blooms is to consider environmental variability.

Co-combustion of Agricultural Straw with Municipal Sewage Sludge in a Fluidized Bed: Role of Phosphorus in Potassium Behavior

The influence of municipal sewage sludge addition on the agglomeration characteristic during straw combustion in a fluidized bed was investigated in a bubbling fluidized-bed reactor (5 kWth) with quartz sand as the bed material. In addition, chemical reactions between the alkali metal and three kinds of phosphorus-containing model compounds were studied to investigate the effect of phosphorus on the behavior of the alkali metal during wheat straw combustion. The element contents, the crystalline phases, the morphology, and the elemental composition in the residual ash samples from the combustion experiments were characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), and scanning electron microscopy (SEM), respectively. The results show that the agglomeration tendency decreases and the defluidization time is prolonged during co-combustion of municipal sewage sludge and wheat straw. The addition of municipal sewage sludge in wheat straw leads to the formation of alkali-rich phosphate silicate t...

Do microorganism stoichiometric alterations affect carbon sequestration in paddy soil subjected to phosphorus input?

Ecological stoichiometry provides a powerful tool for integrating microbial biomass stoichiometry with ecosystem processes, opening far-reaching possibilities for linking microbial dynamics to soil carbon (C) metabolism in response to agricultural nutrient management. Despite its importance to crop yield, the role of phosphorus (P) with respect to ecological stoichiometry and soil C sequestration in paddy fields remains poorly understood, which limits our ability to predict nutrient-related soil C cycling. Here, we collected soil samples from a paddy field experiment after seven years of superphosphate application along a gradient of 0, 30, 60, and 90 (P-0 through P-90, respectively) kg.ha-1.yr-1 in order to evaluate the role of exogenous P on soil C sequestration through regulating microbial stoichiometry. P fertilization increased soil total organic C and labile organic C by 1-14% and 4-96%, respectively, while rice yield is a function of the activities of soil β-1,4-glucosidase (BG), acid phosphatase (AP), and the level of available soil P through a stepwise linear regression model. P input induced C limitation, as reflected by decreases in the ratios of C:P in soil and microbial biomass. An eco-enzymatic ratio indicating microbial investment in C vs. P acquisition, i.e., ln(BG): ln(AP), changed the ecological function of microbial C acquisition, and was stoichiometrically related to P input. This mechanism drove a shift in soil resource availability by increasing bacterial community richness and diversity, and stimulated soil C sequestration in the paddy field by enhancing C-degradation-related bacteria for the breakdown of plant-derived carbon sources. Therefore, the decline in the C:P stoichiometric ratio of soil microorganism biomass under P input was beneficial for soil C sequestration, which offered a "win-win" relationship for the maximum balance point between C sequestration and P availability for rice production in the face of climate change.