Increased Phosphate Levels Research Articles

Effects of different levels of salt and phosphate on some emulsion attributes of the common carp ( Cyprinus carpio L., 1758)

The effects of different solutions of phosphate (K 2HPO 4) and salt (NaCl) on the emulsion properties of fresh common carp ( Cyprinus carpio L., 1758) was studied by using a model system. The pH value of the minced carp, salt and phosphate slurries ranged between 6.80 and 7.53. The effects of phosphate on pH values were statistically significant ( p<0.01). Emulsion capacity (EC) of the carp meat was between 253.15 and 307.93 ml oil/g protein, and EC significantly ( p<0.01) increased with the increasing phosphate levels in the presence of 0.0 and 1.0% salt. The EC increased with salt levels but it was not statistically significant ( p<0.01). In general, emulsion stability (ES) of the treatments was between 65.13 and 77.13%. ES significantly ( p<0.01) increased with the increasing phosphate levels in the 0.0 and 2.0% salt groups. One percent salt and 0.50% K 2HPO 4 gave significantly ( p<0.01) higher ES compared to the no salt counterparts. Emulsion viscosity (EV) value of the samples was between 2500 and 5650 mPa s. EV values increased with the increasing phosphate levels in 0.0 and 1.0% salt groups, and a statistically significant ( p>0.01) difference was determined in 2.0% salt and 0.50% phosphate-containing groups. As a result, the use of carp meat in the presence of 2.0% salt and 0.50% phosphate in the processing of emulsified fish products might produce a potential raw material for better utilization of these fishes.

Mechanisms of vascular calcification in uremia

Vascular calcification and cardiovascular disease mortality are highly correlated with increased serum phosphate levels in end-stage renal disease patients. Mechanistic studies in cultured human smooth muscle cells (SMCs) indicate that increased phosphate levels induces both calcification and phenotypic transition through a pathway requiring a sodium-dependent phosphate cotransporter. Thus, in addition to contributing to increased calcium x phosphate product (Ca x P), hyperphosphatemia may have direct effects on SMCs that predispose these cells to calcium deposition in end-stage renal disease patients.

A member of the germin-like protein family is a highly conserved mycorrhiza-specific induced gene.

A Medicago truncatula cDNA encoding a germin-like protein (GLP) was isolated from a suppression subtractive hybridization cDNA library enriched for arbuscular mycorrhiza (AM)-induced genes. The MtGLP1 amino acid sequence shows some striking differences to previously described plant GLP sequences and might therefore represent a new subgroup of this multigene family. The MtGlp1 mRNA was strongly induced in roots and root cultures colonized by the AM fungus Glomus intraradices. Whereas MtGlp1 is strongly induced in AM, no transcripts of the gene were detected in non-infected roots or in roots after infection with the oomycete root pathogen Aphanomyces euteiches or with Rhizobia. Increased phosphate levels during fertilization also could not stimulate MtGlp1 transcription. Hence, MtGlp1 induction seems to be an AM-specific phenomenon. In situ hybridization showed that MtGlp1 is localized in arbuscule containing cells. A putative orthologue of this AM-specific GLP gene could be localized in a second legume Lotus japonicus, indicating that the regulation of a member of the GLP family belongs to a conserved mechanism in AM regulation in different plant species.

Effects of inorganic and organic phosphate exposure on aspects of reproduction in the common sea urchin Lytechinus variegatus (Echinodermata: Echinoidea).

The common nearshore sea urchin Lytechinus variegatus is capable of surviving exposure to inorganic phosphate concentrations as high as 3.2 mg/l(-1) and organic phosphate concentrations of 1,000 mg/l(-1). However, chronic exposure to low, medium, or high sublethal concentrations of these phosphates inhibits gonadal tissue indices and spawning activity while altering biochemical composition of gonads, reducing size frequencies of oocyte diameters, and changing gonadal volume fractions. Gonad indices declined significantly in individuals maintained in all phosphate concentrations after both one- and two-month exposures, while percentages of ripe individuals (oozing gametes upon dissection) were reduced after a two-month exposure in individuals maintained in medium and high organic phosphate concentrations. Levels of carbohydrates and lipids were lower in gonads of individuals maintained in all concentrations of both phosphates. Size frequency distributions of oocyte diameters revealed a dramatic decrease in oocyte size with increasing concentrations of both phosphates. Gonadal volume fractions of developing male and female gametes decreased with exposure to increasing phosphate levels. Volume fractions of nutritive phagocytes declined in testes of individuals held in the highest concentration of organic phosphate but displayed no significant change in ovaries. Volume fractions of mature gametes also decreased in gonads of individuals exposed to increasing concentrations of inorganic phosphate, but they remained constant in individuals exposed to all concentrations of organic phosphate. These findings indicate that shallow-water populations of L. variegatus subjected to inorganic and organic phosphate pollutants will exhibit stress that may impair reproductive output, gametogenesis, and spawning in the natural environment.

Temporal Variations of Nutrients, ­Chlorophyll a and Particulate Matter in Three Coastal Lagoons of Amvrakikos Gulf (Ionian Sea, Greece)

Abstract. The temporal variations of nutrients, chlorophyll a (chl a), suspended particulate matter (SPM) and particulate organic carbon (POC) were measured over 12 months in three shallow coastal brackish water lagoons of the Amvrakikos Gulf, Ionian Sea. Two of the lagoons, Tsoukalio and Rodia, are interconnected but separated from Logarou by a narrow strip of land. Logarou has a better water exchange with the sea as indicated by the higher salinity and dissolved oxygen concentrations and the smaller variation of the above‐mentioned parameters. Nitrate concentrations were largely the same in the three lagoons and higher than in the Amvrakikos Gulf. Phosphate concentrations in Logarou exceeded by far those of Tsoukalio/Rodia; the increased phosphate levels recorded in January caused an extended phytoplankton bloom with chl a concentrations higher than in the other two lagoons. Chl a in Tsoukalio was positively correlated with nitrate whereas in the most shallow lagoon, Logarou, it showed a positive correlation with light winds (force 4 and lower), probably caused by resuspension from the sediment. Increased phytoplankton biomass in Logarou coupled with the better water exchange may be related to the higher fish production in this lagoon.

Phosphate is a specific signal for induction of osteopontin gene expression

Osteopontin is a phosphorylated glycoprotein secreted to the mineralizing extracellular matrix by osteoblasts during bone development. It is believed to facilitate the attachment of osteoblasts and osteoclasts to the extracellular matrix, allowing them to perform their respective functions during osteogenesis. Several other functions have been suggested for this protein, and its up-regulation is associated with various disease states related to calcification, including arterial plaque formation and the formation of kidney stones. Although expression of this gene has been demonstrated in multiple tissues, its regulation is not well understood. Our previous studies on the roles of the retinoblastoma protein (pRB) and p300/CBP in the regulation of osteoblast differentiation revealed a link between osteopontin induction and the synthesis of alkaline phosphatase. In this paper, we describe results specifically linking induction of osteopontin to the enzymatic activity of alkaline phosphatase in the medium, which results in the generation of free phosphate. This elevation of free phosphate in the medium is sufficient to signal induction of osteopontin RNA and protein. The strong and specific induction of osteopontin in direct response to increased phosphate levels provides a mechanism to explain how expression of this product is normally regulated in bone and suggests how it may become up-regulated in damaged tissue.

Seeing red: The story of prodigiosin

Publisher Summary S. marcescens has played an important role in the history of bacterial taxonomy, in research on the transmission of bacterial aerosols, in the study of emerging nosocomial infections, and in the understanding of secondary metabolite biosynthesis. The prodigiosin pigments have intrigued organic chemists and pharmacologists, and play roles in the treatment of infectious diseases such as malaria, and perhaps as immunosuppressant agents. Undecylprodiginine played an important role in the first cloning of a gene, playing a defined role in the biosynthesis of an antibiotic. An O-methyltransferase gene was isolated by complementation and the color of undecylprodiginine was used as the selectable phenotype. The regulation of prodigiosin biosynthesis is complex, being influenced by increased glucose levels and decreased by increased phosphate level. The antibiotic resistance of many strains of S. marcescens is a serious problem with rapid horizontal transfer of drug resistance by plasmids.

Cadmium Alters Phosphate Level and Suppresses Activity of Phosphorolytic Enzymes in Germinating Rice Seeds

AbstractThe effect of increasing concentration of Cd on the metabolic status of phosphate and the activity of its metabolizing enzymes acid phosphatase, alkaline phosphatase and inorganic pyrophosphatase were examined in germinating rice (Oryza sativa) seeds. During a 0‐120 h germination period in the two rice cvs., Ratna and Jaya, 500 μM Cd caused a 2‐3‐times increase in phosphate level in embryo axes compared to controls. Cadmium concentration of 500 μM in situ caused about 12‐14% and 20‐30 % decline in acid phosphatase activity in endosperms and embryo axes respectively during 72‐96 h of germination. With 500 μM Cd treatment in situ about 27‐43 % inhibition in alkaline phosphatase activity was noticed in endosperms and 40‐70 % in embryo axes. With 2 mM Cd salt in vitro about 60‐92 % inhibition in the activity of acid phosphatase and 80‐95 % inhibition of alkaline phosphatases was observed in enzyme preparations from embryo axes. However, a Cd level of 50‐100 μM caused stimulation in the activity of inorganic pyrophosphatase. Isoenzymic studies revealed four acid phosphatase isoenzymes in embryo axes with Rf values 0.15, 0.24, 0.36 and 0.49 and three isoenzymes in endosperms with Rf values 0.18, 0.24 and 0.40. The band intensities decreased under Cd treatment. Results indicate possible suppression of the phosphorolytic activities in germinating rice seeds under Cd stress.

Phytic acid‐mediated regulation of secondary metabolism in Streptomyces thermoviolaceus grown in simple and complex media

A.D. BRABBAN AND C. EDWARDS. 1997. Primary and secondary metabolism in the thermophilic actinomycete Streptomyces thermoviolaceus were found to be strongly regulated by phosphate in complex and defined media. Increasing phosphate levels in glutamate minimal salts media led to peak production of granaticin at 5 mmol phosphate, a concentration that was growth-limiting, before total inhibition of antibiotic production at 50 mmol. Product formation in particulate rapeseed meal-based media was found to be less affected by the initial phosphate concentration. The addition of 5 mmol phytic acid to proline minimal salts media led to an increase in the concentration of phosphate optimal for antibiotic production from 5.7 mmol to 15 mmol and reduced inhibition at higher concentrations. Phytic acid was shown to bind phosphate from minimal salts media and inhibit the growth of the organism at high concentrations. Differences in the production of granaticin by S. thermoviolaceus in two rapeseed meal-derived media were shown to be phosphate and phytic acid-related. In particulate rapeseed, the additional phosphate from minimal salts media was predominantly bound in an organic-soluble complex, while in extracted rapemeal media, phosphate was present predominantly in the free form. Overall, the work suggests that reduction in growth rate, which can be brought about by a variety of factors including low phosphate concentrations, is the critical factor for the onset of secondary metabolism in S. thermoviolaceus.

Emulsifying capacity of coconut proteins as a function of salt, phosphate, and temperature

AbstractNitrogen solubilities of proteins in defatted coconut flour (CF) and coconut protein concentrate (CPC), prepared by ultrafiltration, were determined in water and 2% NaCl. The effect of temperature, disodium phosphate, and salt on emulsifying capacities (EC) of these products also were investigated by a model system. Between pH 4.0 and 5.0, nitrogen solubilities of CF and CPC in water were lower than those in salt solutions. In salt solutions, the nitrogen solubility was lowest at pH 1, and increased steadily as pH increased from 3.0 to 6.0. CF had higher EC values than CPC at all salt and phosphate levels. Additionally, increased phosphate level generally increased the EC at both salt levels, but these increases were not significant at 0.9% phosphate level as compared to the 0.7% phosphate level (P&lt;0.05). Although the emulsifying temperature of 40°C showed higher EC values than both 60 and 80°C at all salt and phosphate levels, the overall temperature effect was not significant (P&gt;0.05). However, EC decreased significantly with the addition of salt at all phosphate levels.

Effects of liming on shallow acidified moorland pools: a culture and a seed bank experiment

To study the effects of liming on water chemistry and the development of aquatic macrophytes, culture experiments with Littorella uniflora (L.) Aschers. and Juncus bulbosus L. were carried out. The addition of powdered limestone to acidified moorland pools led to increased phosphate levels in the water layer and increased carbon dioxide levels in the sediment pore water and the water column; this resulted in an excessive growth of Juncus bulbosus. Similar observations were made in seed bank experiments, conducted in a greenhouse. After 2 years the abundance of J. bulbosus was very high. Littorella uniflora and Lobelia dortmanna L. germinated spontaneously and developed in mini-ecosystems with sediments from the Padvindersven and the Peetersven, respectively, two moorland pools from which these species had disappeared a few decades ago. Spontaneous germination and development of endangered soft water macrophytes only occurred on sediments after removal of the organic sapropelium layer. Therefore, this study showed that in order to restore the original water chemistry of acidified moorland pools, removal of the organic sapropelium layer is necessary, as well for improving vegetation development.

Vegetation succession in lakes of West Connemara, Ireland: comparing predicted and actual changes

Abstract. Changes in the vegetation of lakes and wetlands were investigated over a period of 18 years. It was assumed that changes in vegetation were related to changes in agricultural land use resulting in increased phosphate levels in surface waters. Data were collected in 1975, 1988 and 1993. Multivariate techniques were used to relate changes in vegetation to changes in environmental factors. With the use of a Markovian chain model, vegetation development was projected into the future. Projections based on vegetation dynamics between 1975 and 1988 were compared with actual changes in the vegetation.The vegetation dynamics appeared stable on a regional scale but quite dynamic on a local scale. A continuous decline in species diversity was noted as well as an overall increase of phosphate level. However, only minor changes in vegetation could be attributed to this increase of phosphate. Major changes were a result of fluctuations in water level. These changes coincide with periods of drier and wetter climate. Because of the fluctuating nature of these changes, predicted vegetation change did deviate from the observed change.

Internal eutrophication, iron limitation and sulphide accumulation due to the inlet of river Rhine water in peaty shallow waters in the Netherlands

Due to agricultural activities and increased water extraction, ground water levels have generally decreased in large parts of the peaty lowlands in the Netherlands. As a result (iron containing) seepage has decreased in many regions while alkaline river Rhine water, rich in sulphates and poor in iron, has been used to compensate for the shortage of water. This has resulted in increased alkalinity and organic sediment breakdown. Increased sulphate reduction leads to iron sulphide precipitation and internal alkalinity generation. As a result of these processes phosphate and ammonium levels in sediment pore water have increased strongly. Release of these nutrients to the water layer has resulted in internal eutrophication of the peatland ecosystems. Further, iron levels have decreased strongly due to decreased seepage and iron sulphide precipitation. As a result sulphide accumulates in sediment pore water and reaches toxic levels. Furthermore, decreased iron levels appear to be correlated with increased phosphate levels in sediment pore water. The strong decline of aquatic macrophytes in many minerotrophic peatlands in non agricultural regions in the Netherlands can probably be attributed to internal eutrophication, internal intoxication and iron limitation, resulting from changed hydrological situations i.e. decreased seepage and inlet of river Rhine type water.

Effect of Nutrients on Biofilm Formation by Listeria monocytogenes on Stainless Steel

The effect of nutrients on the development of biofilms by Listeria monocytogenes was investigated using semicontinuous culture in a chemically defined minimal medium (modified Welshimer's broth, MWB). Inoculated slides were used for the development of biofilms for 12 days at 21°C under various nutrient conditions. Biofilms were quantified by measuring the percentage of area covered by cells, using computerized image analysis. MWB allowed slow development of Listeria monocytogenes biofilms. Glucose levels between 1 and 20 g/l did not affect biofilm development. A reduction or increase in phosphate level from that occurring in MWB (37.52 g/l) reduced biofilm development. The degree to which biofilms initially developed was associated with amino acid concentration within the range of 0.12 to 6 g/l; however, after 12 days of incubation, the amount of biofilm produced was not affected by amino acid concentration. Replacement of amino acids in MWB with tryptone initially enhanced biofilm development, but the effect was not significant after 12 days of incubation. Of five carbohydrates tested, mannose and trehalose enhanced biofilm development.

Sulphate-mediated iron limitation and eutrophication in aquatic ecosystems

In large parts of the peaty lowlands of The Netherlands, alkaline, sulphate-enriched river water poor in iron is let in to compensate for decreased ground water levels. As a result, iron input rates decrease while sulphate reduction rates in the anaerobic sediment increase. Iron sulphide precipitatio and decreased iron input result in iron exhaustion, sulphide accumulation and increased phosphate mobilization in the anaerobic sediments. Futhermore, iron shortage and sulphide toxicity can occur in aquatic species while disturbance of the iron cycle results in increased phosphate levels in the water layer.

Salt, Phosphate and Oil Temperature Effects on Emulsion Capacity of Fresh or Frozen Meat and Sheep Tail Fat

ABSTRACTThe effects of K2HP04, NaCl and oil temperature on emulsion capacity (EC) and microstructure of fresh and frozen Turkish beef was studied by utilizing a model system. EC of frozen meat was 6.4% higher than fresh meat. EC also increased with increasing phosphate levels increasing 8.5 and 10.4% over the control with 0.50 and 0.75% phosphate respectively. EC increased 1.6% for 3.0% salt over 2.5% salt. Microstructure photographs of the phosphate containing emulsions indicated the protein aggregates diminished and the emulsion was more homogeneous.

ダイコンの赤心症発生に及ぼすホウ素およびリン酸施用の影響

Effects of boron and phosphate applied to the different kinds of soils and solution culture on the internal browning of roots in summer-sown Japanese radish were investigated. With hydroponics, the relationship between the incidence of internal browning and polyphenol concentrations and polyphenol oxidase activity in roots was also examined.1. Borax, applied to the brown lowland soils (sand) and medium and coarse-textured yellow soils (sandy loam), was effective in reducing internal browning and increasing boron concentrations in the roots, but that applied to the andosols (loam) was ineffective. Super phosphate application which increased phosphorus concentrations in the roots was effective in decreasing internal browning even in andosols.2. The occurrence of internal browning induced by the absence of boron in the hydroponic solution was severe at 29 °C as compared to 21 °C, although boron concentration in the root was relatively high at the higher temperature. These results suggest that the occurrence of internal browning can not be explained merely by concentrations of boron in the roots.3. The polyphenol oxidase activity but not the polyphenol concentrations in the roots increased in the absence of boron in the hydroponic solution. Therefore, the internal browning is considered to be caused by the increased polyphenol oxidase activity in response to the boron deficiency in the root.In the presence of boron in the solution, the internal browning did not occur, irrespective of phosphorus concentrations in the solution. On the other hand in the absence of boron, the occurrence of internal browning and polyphenol oxidase activity in the roots decreased with the increase in phosphate levels.

Model system evaluations of the effects of different levels of K 2HPO 4 NaCl and oil temperature on emulsion stability and viscosity of fresh and frozen turkish style meat emulsions

The effects of different levels of K 2HPO 4, NaCl, and the effects of oil temperature used in the evaluation of emulsion stability and viscosity of fresh and frozen beef (fat level adjusted with tail fat from sheep) was studied by utilizing a model system. Emulsion stability (ES) and emulsion viscosity (EV) of frozen meat tissue were both decreased, by 3·6% and 10·5% respectively, when compared to fresh meat. ES was decreased by 4·0% and 3·7% at 5°C and 11°C oil temperature respectively when compared to 21°C. While EV decreased 12·2% at 11°C compared to 21°C, it did not show any statistically significant ( P < 0·01) change at 5°C oil temperature. ES and EV were elevated with the addition of phosphate and increasing phosphate levels. These increases for ES were 3·9% and 3·7% with 0·50% and 0·75% phosphate levels respectively, when compared to the 0·00% phosphate control group. Also, the increases for EV were 22·3% and 27·0% with 0·50% and 0·75% phosphate levels respectively, compared to the 0·00% phosphate control group. The alteration of the ES was not statistically P < 0·01) significant for the 0·50% phosphate level when compared to the 0·75% phosphate level. The ES decreased 1·1% for a 3·0% salt level when compared to a 2·5% salt level, and there was statistically ( P < 0·05) no effect on the EV.

Uptake, accumulation and translocation of arsenate in arsenate‐tolerant and non‐tolerant Holcus lanatus L.

summaryUptake, translocation and accumulation of arsenate was determined in arsenate‐tolerant and non‐tolerant genotypes of Holcus lanatus L. Over a 6 h period of growth in 005 mol m−3arsenate, non‐tolerant genotypes accumulated arsenate to a much greater extent than tolerant plants. Tolerant plants transported a much greater proportion of As to their shoots compared with non‐tolerant plants. Phosphate at a concentration of either 0.05 or 0.5 mol m−3decreased arsenate uptake in both tolerant and non‐tolerant genotypes. When arsenate uptake was determined over 3 d at the same arsenate concentration, non‐tolerant plants grown in the presence of 0 and 0.05 mol m−3phosphate died, while those growing in 0.5 mol m−3phosphate survived and continued to take up arsenate. At all three phosphate levels tolerant plants survived. Over the 3 d period transport of arsenate to the shoots decreased. With increasing phosphate levels in solution transport of arsenate to the shoots increased in tolerant plants. The results from these experiments are discussed in terms of strategies for metal tolerance in this species.

Effect of phosphorus on the acidity of γ-alumina and on the thermal stability of γ-alumina supported nickel—molybdenum hydrotreating catalysts

The influence of phosphate on the acidity and thermal stability of γ-alumina and alumina supported hydrotreating catalysts has been investigated. The results from the temperature-programmed desorption of ammonia showed that the addition of phosphate significantly alters the acid strength distribution of γ-alumina. While the number of strong acid sites is reduced, the concentration of medium strength acid sites is progressively increased with increasing phosphate level. Phosphate ion has a very significant effect in improving the thermal stability of γ-alumina with regard to sintering and phase transition to α-alumina, but, in the presence of molybdena it loses the stabilizing function. Calcination of molybdena based catalyst extrudates in their oxidic form (MoO3/γ-Al2O3, MoO3-PO4/γ-Al2O3, NiO-MoO3-PO4/γ-Al2O3) at high temperatures results in considerable reduction of the mechanical strength. The possible role of MoO3 in disrupting the stabilizing effect of phosphate ion with regard to the sintering and phase transformation behavior of alumina support is discussed.