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1.
《Process Biochemistry》2014,49(12):2207-2213
Enhanced biological phosphorus removal (EBPR) technology has been widely considered as a key strategy in preventing eutrophication and recognized as the advancing front of research in wastewater treatment. The key to keep its high efficiency in biological phosphorus removal is to optimize the operation and management of the system. Previous research in this field has undoubtedly improved understanding of the factors hindered overall efficiency of EBPR. However, it is obvious that much remains to be learnt. This paper attempts to review the fundamental understanding in factors inhibiting the stability and reliability of the EBPR systems in the state-of-the-art research. In view of modeling the EBPR systems, an appropriate extension of the current mechanistic models with these inhibitory factors is recommended in order to better simulate and predict the behavior of full-scale and lab-scale EBPR plants. From the perspectives of the further mechanistic and multi-factors study, the direction of denitrifying dephosphatation and granules/biofilms are also discussed. This comprehensive overview will not only help us to understand the overall mechanism of the EBPR process, but also benefit the researchers and engineers to consider all the possible factors affecting the process in the urban sewage treatment plants. 相似文献
2.
C. F. C. Bonting H. W. van Veen A. Taverne G. J. J. Kortstee A. J. B. Zehnder 《Archives of microbiology》1992,158(2):139-144
The response of Acinetobacter strain 210A to low phosphate concentrations was investigated in P- or C-limited chemostat cultures. The organism accumulated poly--hydroxybutyric acid under P-deprivation, at phosphate concentrations ranging from 0.1 to 0.7 mM. The amount of biomass was proportional to the phosphate concentration in the medium and no polyphosphate was formed. When shifting a culture from P- to C-limitation phosphate was accumulated as polyphosphate. No poly--hydroxybutyrate could be detected in these cells. The amount of polyphosphate in the cell showed a hysteresis. When cultures were shifted from low to high phosphate concentrations, polyphosphate reached a maximum of about 60 mg P per gram of dry weight at about 3 times excess phosphate (ca. 2.5 mM Pi). It decreased to 45 mg P per gram dry weight at approximately 5 times the phosphate needed for growth (ca. 3.5 mM Pi). In the reverse case (high to low) polyphosphate did never exceed 45 mg P per gram dry weight. The specific activities of alkaline phosphatase and the phosphate uptake system were induced at residual Pi concentrations below the detection limit (<10 M). The specific uptake rate followed also a hysteresis. The specific activities of polyphosphatase and polyphosphate: AMP phosphotransferase increased when polyphosphate formation was possible.Abbreviations HPP
High polymeric polyphosphates
- PHB
Poly--hydroxybutyric acid
- PPn
Polyphosphate
- PQQ
Pyrrolo-quinoline quinone
- U
1 mol product formed · min-1 相似文献
3.
Summary The ectomycorrhizal fungus,Paxillus involutus, produces sclerotia in culture. These can be induced to form on agar medium by exposing mycelium grown at 25°C to various temperatures between6°C and 15°C. Sclerotia formed at 10°C and above were large and covered with drops of exudate, while those formed at 6°C or 8°C were very small and did not produce an exudate. Mature sclerotia were bounded by a compact rind and contained abundant storage reserves. Histochemistry of the larger sclerotia showed large quantities of protein stored as protein bodies in the cytoplasm, lipid present as small droplets, glycogen granules stored in the cytoplasm and polyphosphate present as small granules in the cytoplasm and in the protein bodies. Energy dispersive X-ray microanalysis confirmed the presence of phosphate in the granules and was used to map its distribution throughout the sclerotium. The smaller sclerotia induced at 8°C and below on the same medium had the same basic structure and composition, but lacked the complex phenolic cell network found in large sclerotia, and had abundant extracellular polysaccharides. The rind was not well developed and these small sclerotia are interpreted to have been arrested at an early stage of development. 相似文献
4.
The techniques of 27Al- and 31P-nuclear magnetic resonance (NMR) spectroscopy were used to investigate the interactions of aluminium with intracellular ligands within the mycelium of the ectomycorrhizal basidiomycete Laccaria bicolor (Maire) Orton (S238). The vegetative mycelium was grown on medium containing 0.5 mM AlCl3 for 0.5 to 3 d. The 27Al-NMR spectra showed that aluminium was rapidly taken up and accumulated into polyphosphate complexes in the vacuole. Comparison with Al-polyphosphate complexes obtained in vitro on model systems indicated that Al forms at least three mixed-solvation complexes with Pi and polyphosphates, that there is more than one complex present under any set of conditions, and that the equilibrium between these complexes shifts dramatically with Al concentration in the medium. The high phosphate concentrations in the growth medium favoured the accumulation of the Al-polyphosphate complexes. When mycelium containing Al-polyphosphate complexes was transferred to Al-free nutrient solution for 9 d, the Alpolyphosphate complexes were not remobilized. The sequestration of Al in the polyphosphate complexes could therefore make a significant contribution to the protection of mycorrhizal plants against aluminium toxicity.Abbreviations NMR
nuclear magnetic resonance
- PolyP
polyphosphate(s)
- PP1
terminal phosphate of PolyP
- PP3
middle phosphate of PolyP
We thank Prof. Daniel Canet (Laboratoire de Méthodologie RMN, University of Nancy I, Vandceuvre-lès-Nancy, France) for his constant encouragement and Christine Delaruelle for skilled technical assistance in growing the fungal cultures. This work was supported by a research grant from the Commission of the European Communities (STEP-CT90-0059, Role of Ectomycorrhiza in Stress Tolerance of Forest Trees) to F.M. and a travel grant from the Institut National de la Recherche Agronomique to I.K.; R.C. is a recipient of a Postdoctoral Fellowship from the Natural Sciences and Engineering Research Council of Canada. 相似文献
5.
Comparative in vivo 31P-NMR analyses of mycorrhizal and nonmycorrhizal roots of Pinus sylvestris and the fungus of Suillus bovinus in pure culture were used to investigate alterations in phosphate metabolism due to changes in external pH in the range 3.5–8.5.
All control samples maintained a constant pH in both cytoplasm and vacuole. Mycorrhizal roots and pure fungus, but not nonmycorrhizal
roots, transformed accumulated inorganic phosphate into mobile polyphosphate with a medium chain length. Phosphate uptake
rates and polyphosphate accumulation responded differently to external pH. In all cases, maximal phosphate uptake occurred
at an external pH close to 5.5. At an external pH of 8.5, both roots and fungus showed a distinct lag in phosphate uptake,
which was abolished when the external pH was lowered to 7.5. An irreversible effect on phosphate uptake as a consequence of
variation in external pH was also observed. The central role of the fungus in regulating mycorrhizal phosphate metabolism
is discussed.
Accepted: 15 April 1997 相似文献
6.
Virtually all of the polyphosphate (PP) present in yeast protoplasts can be recovered in a crude particulate fraction if polybase-induced lysis is used for disrupting the protoplasts. This fraction contains most of the vacuoles, mitochondria and nuclei. Upon the purification of vacuoles the PP is enriched to the same extent as are the vacuolar markers. The amount of PP per vacuole is comparable to the amount of PP per protoplast.The possibility that PP is located in the cell wall is also considered. In the course of the incubation necessary for preparing protoplasts, 20% of the cellular PP is broken down. As this loss of PP occurs to the same extent in the absence of cell wall degrading enzymes, it is inferred that internal PP is metabolically degraded, no PP being located in the cell walls.It is concluded that in Saccharomyces cerevisiae most if not all of the PP is located in the vacuoles, at least under the growth conditions used.Non-Standard Abbreviations PIPES
piperazine-N,N-bis-2-ethanolsulfonic acid
- DEAE-dextran
diethylaminoethyl-dextran 相似文献
7.
A variety of preparative methods for in situ X-ray energy dispersive analysis were tested to determine their effects on the elemental composition of polyphosphate bodies in P. boryanum. The bodies were found to contain large amounts of P and K and small amounts of Ca and Mg. Air drying, freeze-drying and freeze-drying from a liquid nitrogen slush all gave similar results. Fixation of the cells in glutaraldehyde and/or OsO4 resulted in loss of the K and enhancement of the Ca peak. Magnesium was lost during embedding in epoxy. 相似文献
8.
Uptake of orthophosphate and deposition of condensed phosphate were investigated in cells of Synechococcus sp. (Anacystis nidulans) deficient in phosphorus or sulfur. When phosphorus was restored to phosphorus-starved cells, uptake was rapid and immediate, with the greatest accumulation occurring within the first hour. Uptake was optimum in the pH 7.5–8.5 range. Long-term (6-day) studies of uptake and deposition with cells exposed to a wide range of sulfur deficiency showed that both processes were greatest when the level of exogenous sulfur was reduced to zero. The increase in cellular phosphorus as determined chemically was in agreement with the increased number and size of polyphosphate bodies at the ultrastructural level. Possible mechanisms for the control of phosphorus uptake and condensed phosphate formation by exogenous sulfur are discussed. 相似文献
9.
Methods of ultracytochemistry and of X-ray energy dispersive analysis have been used to demonstrate that the gamma-like granules in encysted zoospores of the chytrid Rozella allomycis contain polyphosphate. The possibility that cysts contain two classes of polyphosphate granules which differ in structure, in function, and in origin is discussed. 相似文献
10.
Miral V. Lunagariya Khyati P. Thakor Bharat H. Pursuwani 《Nucleosides, nucleotides & nucleic acids》2013,32(8):455-483
AbstractSquare planar mononuclear platinum(II) complexes having general formula [Pt(Ln)Cl2], (where, Ln?=?L1–4) were synthesized with neutral bidentate heterocyclic 1,3,5-trisubstituted bipyrazole based ligands. The synthesized compounds were characterized by physicochemical method such as TGA, molar conductance, micro-elemental analysis and magnetic moment, and spectroscopic method such as, FT-IR, UV–vis, 1H NMR, 13C NMR and mass spectrometry. Biological applications of the compounds were carried out using in vitro brine shrimp lethality bioassay, in vitro antimicrobial study against five different pathogens, and cellular level cytotoxicity against Schizosaccharomyces pombe (S. Pombe) cells. Pt(II) complexes were tested for DNA interaction activities using electronic absorption titration, viscosity measurements study, fluorescence quenching technique and molecular docking assay. Binding constants (Kb) of ligands and complexes were observed in the range of 0.23–1.07?×?105?M?1 and 0.51–3.13?×?105?M?1, respectively. Pt(II) complexes (I–IV) display an excellent binding tendency to biomolecule (DNA) and possess comparatively high binding constant (Kb) values than the ligands. The DNA binding study indicate partial intercalative mode of binding in complex-DNA. The gel electrophoresis activity was carried out to examine DNA nuclease property of pUC19 plasmid DNA. 相似文献