Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PHOSPHORUS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 217 records · Page 12Linked to original sources
PubMed2006

Gene cassette-associated sequences from phosphorus and non-phosphorus removing microbial communities in aerobic:anaerobic sequencing batch reactors.

Mobile gene elements associated with integrons, including as gene cassettes, have been proposed to play an important role in bacterial evolution by providing an extensive genetic resource. This study hypothesized that critical genes for enzymes involved in EBPR systems, including those involved in polyphosphate, PHA and glycogen synthesis, may be present in mobile gene cassettes. Although no such genes were identified in any of the functional and deteriorated enhanced biological phosphorus removal (EBPR) laboratory-scale SBR systems examined here, many of the open reading frames (ORFs) remained unidentified because of the incompleteness of publicly available databases. An ORF of unknown function (SBR6-2) was encountered in deteriorated EBPR system with an unexpectedly high frequency, comprising 35% of the gene cassette-associated sequences for that system.

Aerobiosis↗
PubMedDate not supplied

Enhanced biological phosphorus removal from wastewater by biomass with different phosphorus contents, Part III: Anaerobic sources of reducing equivalents.

Laboratory-scale sequencing batch reactors exhibiting enhanced biological phosphorus removal (EBPR) operated at different influent phosphorus/chemical oxygen demand (COD) ratios were analyzed to evaluate possible anaerobic sources of reducing equivalents. Assuming anaerobic glycogen degradation was the sole anaerobic reducing equivalent source, an anaerobic phase carbon balance showed that glycogen-accumulating metabolism (GAM)-dominated systems were nearly carbon-balanced, but that polyphosphate-accumulating metabolism (PAM)-dominated systems had end-anaerobic phase carbon deficits. An anaerobic-phase reducing equivalent balance showed a reducing equivalent excess for the GAM-dominated systems and a deficit for the PAM-dominated systems, suggesting that glycogen degradation was not the sole reducing equivalent source for PAM. Reducing equivalent balances showed that metabolic models including complete anaerobic tricarboxylic acid (TCA) cycle activity, partial TCA cycle activity, and the glyoxylate bypass could provide the reducing equivalents required in PAM. Metabolic precursors produced in glycolysis, the TCA cycle, or modified versions of the TCA cycle could allow anaerobic growth and account for the PAM carbon deficits. The importance of considering both PAM and GAM activity in evaluating EBPR metabolic models was illustrated.

Anaerobiosis↗
PubMed2002

Phosphorus partitioning during early lactation in dairy cows fed diets varying in phosphorus content.

The effect of dietary P content on P partitioning and excretion during early lactation was evaluated in 13 cows fed diets containing 0.34 (no supplementary P), 0.51, or 0.67% P. All cows were fed a common pre-partum total mixed ration (TMR) (0.28% P), followed by common TMR (0.51% P) for 7 d post-partum. On day 7, cows were randomly assigned to one of the three dietary P treatments. All treatment diets contained 16.6% CP, 15.2% ADF, 26.3% NDF, and 0.74% Ca. Total collections of milk, urine, and feces were conducted during weeks 3, 5, 7, 9, and 11 of lactation. Average body weight (591 kg), milk yield (47.9 kg/d), and DMI (25.2 kg/d) throughout the 10-wk trial were not affected by dietary P content. With increasing dietary P, however, linear increases in P intake (84.7, 135.2, and 161.5 g/d), fecal P (42.3, 87.5, and 108.6 g/d), urinary P (0.32, 1.28, and 3.90 g/d), and total P excretion (42.6, 88.8, and 112.5 g/d) were observed. Apparent P digestibility (49.0, 34.4, and 32.8% of P intake) decreased quadratically with increasing dietary P. Phosphorus balance was highly variable, but cows fed the 0.34% P diet were in negative P balance longer than were cows fed diets containing 0.51 or 0.67% P. With increasing dietary P, serum concentrations of inorganic P increased linearly, but serum Ca and Mg concentrations decreased. Increasing dietary P increased fecal and urinary P excretion in early lactation cows. Increased duration of negative P balance and changes in blood mineral concentrations suggest that cows fed low P diets mobilized more P from body reserves than cows on medium- and high-P diets.

Animals↗
PubMed1987

Bioavailability of phosphorus from defluorinated and dicalcium phosphates and phosphorus requirement of calves.

Bioavailability of P from defluorinated phosphate and dicalcium phosphate and the P requirement were studied with 63 male Holstein calves. A P depletion diet containing .08% total P on a dry matter basis was fed to all animals for 4 wk beginning at 6 wk of age and 61 kg weight. Calves developed typical signs of P deficiency. The depletion period was followed by a 6-wk experimental period in which the same depletion diet was used as a control. Phosphorus from each of the two sources was added to make diets containing .14, .20, and .32% total P. Source of supplemental P did not affect weight gains, feed consumption, feed efficiency, serum inorganic P, serum alkaline phosphatase, or bone ash.

Animals↗
PubMed1996

Improving phytate phosphorus availability in corn and soybean meal for broilers using microbial phytase and calculation of phosphorus equivalency values for phytase.

Two experiments were conducted to determine the effectiveness of Natuphos phytase for improving P availability of soybean meal-based semipurified diets (SP, Experiments 1 and 2) and corn-soybean meal-based diets (CS, Experiment 2) fed to broilers (1 to 21 d). There were 360 and 288 birds fed the SP diets in Experiments 1 and 2, respectively, and 288 birds were fed the CS diets in Experiment 2. Phosphorus equivalency values for phytase were calculated. The basal diets were formulated to contain 0.27% nonphytate P (nP); the SP basal diet contained 0.45% total P (tP) that included 0.17% P as defluorinated phosphate; the CS basal diet contained 0.51% tP that contained 0.12% P as defluorinated phosphate. Both basal diets were supplemented with defluorinated phosphate to provide 0.36, 0.45, of 0.54% nP or with 350, 700, or 1,050 U of phytase/kg diets. Supplementing defluorinated phosphate and phytase linearly increased BW gain (P < 0.001), feed intake (P < 0.001), and percentage ash of dried toes (P < 0.01). Phytase addition increased apparent retention of P (P < 0.02), Ca (P < 0.005 in Experiment 2), and N (P <0.06 in Experiment 2 for CS), increased apparent digestibility of DM (P < 0.04), and linearly decreased (P <0.005) P excretion. In comparison to the 0.45% np diet, P excretion was reduced 42 to 51% by addition of phytase. The addition of defluorinated phosphate linearly decreased apparent retention of P (P < 0.02) and Ca (P < 0.005 in Experiment 2), and increased P excretion (P < 0.007). The average of released P by phytase calculated by solving nonlinear or linear response equations of P and phytase levels for SP diets in Experiments 1 and 2 gave a P equivalency value 1 g P = 1,146 U of phytase. The P equivalency value for CS diets fed only in Experiment 2 was 785 U of phytase = 1 g P as defluorinated phosphate. These studies show that microbial phytase is effective for improving P availability and for decreasing P excretion. Added phytase can also increase Ca and N retention.

6-Phytase↗
PubMed2003

The competition between PAOs (phosphorus accumulating organisms) and GAOs (glycogen accumulating organisms) in EBPR (enhanced biological phosphorus removal) systems at different temperatures and the effects on system performance.

It is well known and firmly established that the rate of chemical and biochemical reactions slow down as temperature decreases. Nevertheless, several studies have reported that the efficiency of enhanced biological phosphorus removal (EBPR) improves as temperature decreases. However, several recent studies have reported that EBPR reaction rates decrease with temperature decrease in accordance with the Arrhenius relationship. This study was designed to more thoroughly investigate this controversy using two UCT plants fed with a synthetic wastewater consisting primarily of acetate as the COD form, and a small amount of supplemental yeast extract. Experiments were performed over temperatures ranging from 5 to 20 degrees C. The results showed that, even though the kinetic rates decrease as temperature decreases, EBPR systems perform better at colder temperatures. The reason for better system performance is apparently related to reduced competition for substrate in the non-oxic zones, which results in an increased population of PAOs and, thus, greater EBPR efficiency. The proliferation of PAOs apparently occurs because they are psychrophilic whereas their competitors are not. The experiments showed that the EBPR sludges accumulated high concentrations of both PHA and glycogen at 20 degrees C, but accumulated more PHA and much less glycogen at 5 degrees C. Although the results could be interpreted as the result of changes in the PAO-GAO competition, Mann-Whitney non-parametric comparisons of transmission electron microscopy examinations revealed no indication of the presence of GAOs population under any temperature conditions. Regardless, mass balances of the glycogen data showed that the involvement of glycogen is less at cold temperature, even though EBPR was greater. Unlike current EBPR models (e.g. Mino model), the results suggest that glycogen metabolism is not a precursor for EBPR biochemistry. The results also indicate that temperature not only may cause selective pressure on the dominant organisms, but also may force them to use a different metabolic pathway as temperature decreases.

Acetates↗
PubMed1992

Increasing plasma phosphorus values by enriching with phosphorus the "acid concentrate" of a bicarbonate-buffered dialysate delivery system.

Each of seven hypophosphatemic hemodialysis patients was dialyzed with a phosphorus-enriched, bicarbonate-buffered dialysate. The latter was prepared by the introduction of sodium phosphate salts to the "acid concentrate" of a bicarbonate-buffered dialysate delivery system. The patients tolerated the procedure well and their hypophosphatemia improved.

Aged↗
PubMedDate not supplied

[Phosphorus-calcium metabolism in patients with malabsorption syndrome on diets with various ratios of calcium and phosphorus].

Phosphorus-calcium metabolism was studied in 74 patients with malabsorption syndrome that had developed as a result of chronic enteritis or after resection of the small intestine. The results of the treatment of 21 patients who received diets with Ca/P ratio--1:1.5 (bread enriched with Ca was included into the ration) have shown that dietotherapy led to the correction of the initial hypocalcemia and hyperphosphatemia.

Calcium↗
PubMed1983

[In vitro estimation using radioactive phosphorus of the phosphorus requirements of rumen microorganisms].

Microbial requirements for P were assumed to be a function of the amount of microbial protein synthesis (microbial growth) and of the quantity of organic matter (OM) fermented in the rumen. The relationships among P incorporation into microbial matter and protein synthesis, ammonia utilization, volatile fatty acid (VFA) production and organic matter fermented (OMF) were studied in short-term incubations (3 h) using 32P-labelled phosphate. The amount of P incorporated was calculated from extracellular phosphate pool specific activity and the radioactivity incorporated into the microbial sediment during incubation (table 1). The inocula came from sheep fed a protein-free purified diet. In order to vary the intensity of fermentation, carbohydrates with a wide range of degrees of enzymatic susceptibility were used as substrates and the medium was either provided or was deficient in S and trace elements (table 4). Nitrogen was supplied as ammonium salts. Linear regression analyses showed that P incorporation was positively correlated with the criteria of protein synthesis and OM fermentation (figs. 1, 2, 3, 4). However, there was significant phosphorus incorporation when the value for nitrogen incorporation was zero (equation A: (Pi (mg) = 0.162 NH3-N + 0.376; r = 0.9). This was assumed to result either from energetic uncoupling (fermentation without concomitant bacterial growth) or from the lysis of cold microbial cells only. Equation A would reflect total P incorporation and equation A' Pi (mg) = 0.162 NH3-N (mg), net P incorporation. It was assumed that in vitro microbial requirements for P were in the range of 30-70 mg of P/liter of medium for 3-hour incubation, depending on the intensity of fermentation. From a mean value of microbial N yield of 30 g/kg of DOMR (organic matter apparently digested in the rumen), it was calculated that the total and net P requirements in vivo were 6 and 4.9 g/kg of DOMR, respectively, corresponding to 3.9 and 3.2 g/kg of DOM (digestible organic matter). From equation D, relating Pi to OMF, the P requirements were about 4.4 g/kg of DOM. It is suggested that microbial requirements for P varied from 3 to 5 g of P/kg of DOM, depending on the efficiency of microbial synthesis and the extent of carbohydrate fermentation. These results, considered as indicative, should be checked in in vivo experiments.

Animals↗
PubMed1983

Reliability of single-sample phosphorus fractional excretion determination as a measure of daily phosphorus renal clearance in equids.

In 4 healthy horses and 1 Welsh pony, fractional renal excretions of phosphorus (FEp) determined from 9 hourly time collections taken over a 24-hour period were compared to assess whether a single-sample collection would be an accurate indicator of the daily FEp. The mean FEp for each animal varied from 0.115% to 0.302%; the 2 animals with the highest values were significantly different (P less than 0.05) from the 3 with the lowest values. Individual variation within animals was not great, however, because it was calculated that the 24-hour FEp value could be found within +/- 0.087% of the single sample value 95% of the time in a given animal.

Animals↗
PubMed1996

Mechanisms of intestinal phosphorus absorption and availability of dietary phosphorus in pigs.

Phosphorus (P) is an essential component of many organic and inorganic compounds in vertebrates such as pigs. Therefore, adequate dietary P supply is important to meet daily requirements in order to maintain P homeostasis. Under normal circumstances regulation of P homeostasis occurrs by controlling the absorption rate of inorganic phosphate (Pi) in the upper small intestines and by renal Pi excretion. These processes are mainly mediated by parathyroid hormone (PTH) and calcitriol (1,25-dihydroxycholecalciferol, 1,25-(OH)2D3). If, for example, the Pi level in plasma decreases, renal calcitriol production is stimulated and higher amounts of the hormone are released into the circulation. Calcitriol increases Pi absorption from the intestinal tract by stimulation of a secondary active, sodium-coupled Pi-cotransport system in the upper small intestines. In addition, calcitriol is involved in the mobilization of bone and soft tissue P. Simultaneously, hypercalcemia develops, which can be induced by either increased intestinal Ca absorption and/or Ca mobilization from bone. Hypophosphatemia and hypercalcemia suppress PTH release from the parathyroid glands and thus minimize urinary Pi losses. The concerted action of increased/decreased circulating calcitriol/PTH on the intestinal tract, bone and kidneys normalizes Pi levels in plasma. With respect to adequate P supply in animal nutrition, it must be considered that utilization of dietary P not only depends on absorption capacity of the pig intestinal tract but also on differences in availability of dietary P between ingredients. In feedstuffs of plant origin most of the P is bound as phytate-P and can only be absorbed after enzymatic breakdown of phytic acid by phytases. Intrinsic phytase activity differs between plant materials such as wheat, wheat bran, barley and triticale with higher activities than found in maize and legume seeds subjected to thermal treatments. Supplementation of microbial phytase increased P digestibility more pronounced in those feedstuffs which showed very limited intrinsic phytase activity. At present, a digestibility of about 70% seems to be the upper level for digestibility of P from plant material. From the environmental point of view, an increased digestibility resulting from phytase supplementation offers the possibility to reduce the supplementation of phosphates and the concentration of total P in the diet. Therefore, the amount of P being excreted by the pig can be remarkably reduced. However, the first step for minimizing faecal P excretion should be to supply P in accordance with the animal's requirement.

Animals↗
PubMed1995

The influence of Nootropil on the content of inorganic phosphorus and lipid phosphorus in the blood of patients with intracerebral haemorrhage.

Nootropil exerts positive impact on both intracortical and cortico-subcortical conduction and increases ATP content in the nerve cell which leads to the increase of ribonucleic acid's synthesis necessary for long duration memory and proteins essential for the production of enzymes (3). The cerebral stroke can change the activity of the central vegetative neurons and induce generalized disturbances of the mechanism of metabolism, e. g. in phosphorus and phospholipid economy (1, 2).

Cerebral Hemorrhage↗