• Journal of Plant Biology
• /
• 제19권3호
• /
• pp.71-84
• /
• 1976

In order to observe the phosphate metabolism in chloroplast, the contents of inorganic phosphate and various compounds in chloroplast from spinach leaf tissues were investigated during the reaction in the light and dark in the reaction mixture and the turnover of phosphate in chloroplast was compared with that of whole cell system: 1. The phosphorus of DNA in chloroplast appears to be transferred from inorganic phosphate, while in whole cell system from phosphate pool. 2. $^{32}P-phosphate$ content of acid soluble fraction in chloroplast as well as in whole cell system was more increased in the light than dark during the reaction. It was noted to be caused by the stimulation of sugar phosphate synthesis in the light. 3. It was confirmed that polyphosphate exists in chloroplast as well as whole cell. Acid insoluble polyphosphate content in whole cell system was significantly decreased during the reaction and the similar tendency was also observed in chloroplst. It is, therefore, considered that acid insoluble polyphosphate also play an most important role as a phosphate pool respectively in chloroplast and in cytoplasm. 4. Protein and lipid phosphorus in chloroplast as well as whole cell system were transferred from acid insoluble polyphosphate.

• 한국환경과학회지
• /
• 제11권3호
• /
• pp.257-262
• /
• 2002

The hydroxyapatite(HAp) for the present study was prepared with the wastewater sludge from semiconductor fabrication process and it was crystallized in an electric furnace for 30 min at 90$0^{\circ}C$. The adsorption characteristics of HAp for phosphate ion in aqueous solution has been investigated. The adsorbed ratio of phosphate ion for HAp were investigated according to the reaction time, amount of HAp, concentration of standard solution, pH of solution, and influence of concomitant ions. The amount of adsorbed phosphate ion decreased with the increase of pH due to the mutual electrostatic repulsion between adsorbed phosphate ions and competitive adsorption between phosphate ion and OH- ion in aqueous solution. The maxium amount of the adsorption equilibrium for phosphate ion was about 24 mg/g of HAp. The HAp would likely to be a possible adsorbent for the removal of phosphate ion in the waste water.

• BMB Reports
• /
• 제40권5호
• /
• pp.708-714
• /
• 2007

The two-component signal transduction, which typically consists of a histidine kinase and a response regulator, is used by bacterial cells to sense changes in their environment. Previously, the SphS-SphR histidine kinase and response regulator pair of phosphate sensing signal transduction has been identified in Synechocystis sp. PCC 6803. In addition, some response regulators in bacteria have been shown to be cross regulated by low molecular weight phosphorylated compounds in the absence of the cognate histidine kinase. The ability of an endogenous acetyl phosphate to phosphorylate the response regulator, SphR in the absence of the cognate histidine kinase, SphS was therefore tested in Synechocystis sp. PCC 6803. The mutant lacking functional SphS and acetate kinase showed no detectable alkaline phosphatase activity under phosphate-limiting growth conditions. The results suggested that the endogenous acetyl phosphate accumulated inside the mutants could not activate the SphR via phosphorylation. On the other hand, exogenous acetyl phosphate could allow the mutant lacking functional acetate kinase and phosphotransacetylase to grow under phosphate-limiting conditions suggesting the role of acetyl phosphate as an energy source. Reverse transcription PCR demonstrated that the transcripts of acetate kinase and phospho-transacetylase genes in Synechocystis sp. PCC 6803 is up-regulated in response to phosphate limitation suggesting the importance of these two enzymes for energy metabolism in Synechocystis cells

• 폴리머
• /
• 제36권5호
• /
• pp.549-554
• /
• 2012

난연제 triphenyl phosphate는 HDPE(high-density polyethylene)/EPDM(ethylene-propylene diene monomer)/boron carbide 내에서 miscibility가 좋지 못하여 고분자의 기계적 물성을 크게 저하시킨다. HDPE/EPDM/boron carbide/triphenyl phosphate 블렌드의 분산성을 향상시키기 위해서 상용화제로 PE-g-MAH(polyethylene-graft-maleic anhydride)를 사용하여 블렌딩하였다. Triphenyl phosphate 함량이 증가할수록 인장강도를 크게 저하시킴을 확인하였다. 하지만 상용화제 첨가로 인하여 기계적 물성이 향상되는 것을 확인하였다. Triphenyl phosphate의 분산성의 향상은 SEM 분석을 통해서 확인하였다. HDPE/EPDM/boron carbide/triphenyl phosphate의 내열성과 난연성을 측정하기 위해서 TGA 분석과 LOI 분석을 진행하였다. 분산성이 향상됨에 따라서 triphenyl phosphate 첨가제의 기본적인 특성인 내열성과 난연성이 향상되었으며, 그 결과로 자기 소화성인 21% 이상의 한계산소지수(LOI)를 가지는 HDPE/EPDM/boron carbide/triphenyl phosphate 블렌드를 얻을 수 있었다.

• The Korean Journal of Physiology and Pharmacology
• /
• 제11권2호
• /
• pp.71-77
• /
• 2007

Cisplatin treatment increases the excretion of inorganic phosphate in vivo. However, the mechanism by which cisplatin reduces phosphate uptake through renal proximal tubular cells has not yet been elucidated. We examined the effect of cisplatin on $Na^+$-dependent phosphate uptake in opossum kidney (OK) cells, an established proximal tubular cell line. Cells were exposed to cisplatin for an appropriate time period and phosphate uptake was measured using $[^{32}P]$-phosphate. Changes in the number of phosphate transporter in membranes were evaluated by kinetic analysis, $[^{14}C]$phosphonoformic acid binding, and Western blot analysis. Cisplatin inhibited phosphate uptake in a time- and dose-dependent manner, and also the $Na^+$-dependent uptake without altering $Na^+$-independent uptake. The cisplatin inhibition was not affected by the hydrogen peroxide scavenger catalase, but completely prevented by the hydroxyl radical scavenger dimethylthiourea. Antioxidants were ineffective in preventing the cisplatin-induced inhibition of phosphate uptake. Kinetic analysis indicated that cisplatin decreased Vmax of $Na^+$-dependent phosphate uptake without any change in the Km value. $Na^+$-dependent phosphonoformic acid binding was decreased by cisplatin treatment. Western blot analysis showed that cisplatin caused degradation of $Na^+$-dependent phosphate transporter protein. Taken together, these data suggest that cisplatin inhibits phosphate transport in renal proximal tubular cells through the reduction in the number of functional phosphate transport units. Such effects of cisplatin are mediated by production of hydroxyl radicals.

• 자원리싸이클링
• /
• 제12권4호
• /
• pp.38-43
• /
• 2003

인산염은 유기물의 성장에 필요한 중요한 영양물질이나 아주 미량이 필요하여 폐수 중의 인산염은 오염물질로 작용하며 수생 생태계에 영향을 미친다. 따라서 고농도의 인산염에 대하여 칼슘을 이용한 침전법를 사용하여 인산염의 제거에 관한 연구를 수행하였으며 폐수의 재이용 방면에 대해 고찰하였다. 인산염의 침전 제거 시 pH 조건은 pH 6에서 pH 12로 고려하였는데, pH 12에서 가장 좋은 효율을 나타내었다. 또한 인산염은 침전반응에 의하여 칼슘을 침전반응 당량비의 0.5배 투입한 경우까지 제거율이 급격히 증가하는 경향을 나타내었으며 인산염의 잔존량은 0.0027 mM 까지 낮추는 효과를 가져왔다. 불소가 오염물로 존재하는 상황에서 인산염을 제거하기 위한 실험은 pH 및 농도비에 따라 진행되었으며 pH가 증가할수록 인산염의 제거율은 증가하였다. 또한 인산염 : 불소의 농도비가 증가하여도 인산염의 제거율은 크게 영향을 받지 않은 것이 관찰되었다.

• 한국광물학회지
• /
• 제13권4호
• /
• pp.186-195
• /
• 2000

To study phosphate adsorption on kaolinite, $^{31}$ P MAS NMR(magic angle spinning nuclear magnetic resonance spectroscopy)has been used for kaolinite reacted in 0.1 M phosphate solutions at pH’s from 3 to 11. There are at least 3 different forms of phosphate on kaolinite. One is the phosphate physically adsorbed on kaolinite surface (outer-sphere complexes) or species left after vacuum-filtering. The second is the phosphate adsorbed by ligand exchange (inner-sphere complexes), and the third is Al-phosphate precipitates which are pH dependent. Most of the inner-spherer complexes and surface precipitates are mainly on hydroxided Al(aluminol) rather than hydroxided Si(silanol). These are pertinent with the results obtained from the phosphate adsorption experiments on silica gel and ${\gamma}$-Al$_2$O$_3$ as model compounds, respectively. The two peaks with more negative chemical shifts(more shielded) than the ortho-phosphate peak (positive chemical shift) are assigned to be the inner-sphere complexes and surface precipitates. The $^{31}$ P chemical shifts of the Al-phosphate precipitates are more negative than those of inner-sphere complexes at a given pH due to the larger number of P-O-Al linkages per tetrahedron. The chemical shifts of both the inner-sphere complexes and surface precipitates are more negative than those of inner-sphere complexes at a given pH due to the larger number of P-O-Al linkages per tetrahedron. The chemical shifts of both the inner-sphere complexes and surface precipitates become progressively less shielded with increasing pH. For the inner-sphere complexes, decreasing phosphate protonation combined with peak averaging by rapid proton exchange among phosphate tetrahedra with different numbers of protons is though to be the reason for the peak change. The decreasing shielding with increasing pH for surface precipitates is probably due to the decreasing average number of P-O-Al linkages per tetrahedron combined with decreasing protonation like inner-sphere complexes.

• 한국토양비료학회지
• /
• 제49권3호
• /
• pp.265-270
• /
• 2016

Accumulated Phosphate can be released by ligand exchange reaction of organic acids. The objective of this study was to evaluate effects of the organic acids on the availability of phosphate and the growth of crop in phosphate and salts accumulated soil. Soil samples were collected from farmer's plastic film house. Available phosphate and electrical conductivity of soil were $3,005mg\;kg^{-1}$ and $16.63mg\;kg^{-1}$ which were 6 and 8 times higher than the optimum range of soil for crop growth, respectively. Corns were cultivated in pots for 2 months. Treatments were no treatment (control), phosphate fertilizer (P), citric acid (CA) 1, 5, 10 mM, and oxalic acid (OA) 1, 5, 10 mM. Water soluble phosphorus, available phosphate, corn growth and uptake were determined after cultivation. Results showed that organic acids increased water soluble phosphorus and available phosphate. For the level of 10 mM, the order of effectiveness of organic acids for water soluble P was citric acid (44%) > oxalic acid (32%). Height and dry weight of corns were increased significantly by the treatment of citric acid 1 and 5 mM. Also, corn absorbed more phosphorus, nitrogen, potassium, calcium and magnesium in the treatment of citric acid 1 mM than these of other treatments. Even though phosphate availability of soil was enhanced by addition of citric acid 10 mM, the growth of corns decreased because high concentration of citric acid caused salt damage by increasement of electrical conductivity. Thus, the citric acid of 1 mM has the potential to improve the availability of phosphate and the healthy growth of corns.

• 생명과학회지
• /
• 제23권2호
• /
• pp.242-248
• /
• 2013

본 연구의 목적은 우수한 미생물 제제 개발용 인산염 가용화 균주의 개발이다. 경작지 토양에서 분리한 인산염 가용화 균주의 특성 및 16S rDNA 염기서열을 조사한 결과 Bacillus subtilis HR-1019로 동정되었다. Bacillus subtilis HR-1019는 hydroxyapatite, tri-calcium phosphate 및 aluminum phosphate 3가지의 난용성 인산염을 모두 가용화하였다. 난용성 인산염의 분해능이 최대가 되는 배양온도는 $37^{\circ}C$이었으며, 배양초기 pH가 5.0이었다. 탄소원으로 glucose를 5% 첨가시 가용화능이 높았으며, 가용화된 유리인산의 함량이 증가함에 따라 pH가 크게 감소하였다. 분리균주 HR-1019가 식물병원균에 대하여 균의 생육을 저지하는 clear zone 확인으로 항균효과를 확인하였다.

• Preventive Nutrition and Food Science
• /
• 제21권1호
• /
• pp.44-51
• /
• 2016

The objective of this study was to determine the factors responsible for the changed physiochemical properties of unpeeled shrimp treated in cold phosphate solution ($2{\sim}4^{\circ}C$) with the intervention of 4 factors: phosphate concentration, dipping time, rotation speed, and volume of brine solution. Response surface analysis was used to characterize the effect of the phosphate treatment on shrimps by running 33 treatments for optimizing the experiment. For each treatment, phosphate amount, moisture content, and weight gain were measured. The results showed that phosphate concentration is the most important factor than other factors for facilitating phosphate penetration in the meat of the shrimp and for getting the best result. The optimum condition of phosphate-treated shrimp in this study was 110 to 120 min dipping time, 500 to 550 mL brine solution for 100 g shrimp sample, and 190 to 210 rpm agitation speed. The studied conditions can be applied in fisheries and other food industries for good phosphate treatments.