Phosphorus solubilization

Turner, B.L. and Haygarth, P.M. (2001) Phosphorus solubilization in rewetted soils. Nature4 1,258. 

The importance of microbial turnover in organic phosphorus solubilization... 

Organic phosphorus solubilization by soil drying and wetting cycles... 

It is important to note that results from phosphorus solubilization studies involving water-extraction can be markedly influenced... 

Immiscible solvents like water and oil can be transformed by addition of solubilizers to single-phase solutions. Amphiphilic substances are known as effective solubilizers. Solubilization depends on the HLB of the components that ought to form a single phase and on the kind of solubilizer used. Phosphorus-containing surfactants with their variety of possible molecular structures are solubilizers that can be tailored to the task demanded. 

The sediment reservoir (1) represents all phosphorus in particulate form on the Earth s crust that is (1) not in the upper 60 cm of the soil and (2) not mineable. This includes unconsolidated marine and fresh water sediments and all sedimentary, metamorphic and volcanic rocks. The reason for this choice of compartmentalization has already been discussed. In particulate form, P is not readily available for utilization by plants. The upper 60 cm of the soil system represents the portion of the particulate P that can be transported relatively quickly to other reservoirs or solubilized by biological uptake. The sediment reservoir, on the other hand, represents the particulate P that is transported primarily on geologic time scales. 

The growth of ectomycorrhizal trees is frequently improved by their increased phosphorus (P) accumulation (3), and this, in turn, is related to the intensity of the mycorrhizal infection. Ectomycorrhizal fungi solubilize insoluble forms of A1 and Ca phosphates as well as inositol hexaphosphates, though a wide interstrain variability has been recorded (112). These complex P forms are digested by the secretion of extracellular acid and alkaline phosphomono- and phosphodi-ester-ases. Pi in soil solutions is easily taken up by ectomycorrhizal hyphae and then translocated to the host roots. Its absorption and efflux are probably regulated... 

Saunders and Williams [79] have discussed ignition methods for the determination of organic phosphorus in soils. Sodium carbonate fusion has also been used to solubilize phosphate in soil analyses. 

Amphiphilic tertiary phosphines have their phosphorus donor atom located somewhere in the hydrophobic part of the molecule and should have at least one long alkyl or alkyl-aryl chain carrying a polar head group (Scheme 4. 10). Some of them, such as the sulfonated derivatives, are quite well soluble in water, others, such as Ph2P(CH) COOH (n = 3, 5, 7, 9, 11) are practically insoluble, however, can be easily solubilized with common surfactants (SDS, CTAB etc.). 

Condensed phosphates containing three- atoms of phosphorus are tripolyphosphates, the most important of which is sodium tripolyphosphate (.STPP). This compound reacts with the protein in meat, fish, and poultry to prevent denaturing or loss of fluids. This properly is sometimes called "moisture binding. STPP also solubilizes protein, which aids in binding diced cured meat, fish, and poultry. It also emulsifies fat to prevent separation. 

The XANES spectra of the tribofilms were recorded in the bulk FY mode, and in the surface TEY mode from the ZDDP and calcium phenate. The (S) L-edge and (P) L-edge XANES spectra indicate that sulfur in sulfide form was only present on the topmost part of the film the phosphorus signaled that the topmost surface contained relatively long polyphosphates, and the bulk chemistry of the film contained mostly shorter-chain polyphosphates. Using a range of concentrations of two detergents, it was concluded that calcium phenate influences the film formation much more than calcium sulfonate, and thus calcium phenate solubilize excess ZDDP from film surfaces more effectively (Yin et al., 1997). 

If a water sample contains both soluble and insoluble manganese (Mn) compounds and ions, and it is filtered to separate the dissolved and insoluble fractions, and the filtrate and insoluble residue are analyzed separately, the results can be expressed as total dissolved Mn and total suspended or insoluble Mn. Phosphorus (P) can be determined colorimet-rically as the ortho-phosphate ion, P043, in aqueous samples after a reaction that forms an intensely blue-colored derivative. However polyphosphate ions and other ions and compounds containing P do not form this derivative. Total P in a sample can be determined with the same colorimetric procedure after acid hydrolysis and oxidation of all ions and compounds containing P to P04 3. In some elemental analyses the sample is treated with reagents designed to make available for measurement some fraction of an element or elements but not the total amount. For example, a soil sample may be treated with water at pH 3 to simulate the leaching process of acid rain. A total elemental analysis of the filtrate provides information about just those elements solubilized by the mild acid treatment. This can be called the determination of total mild acid leachable elements. 

Biofertilizers or bioinoculants are formulates of beneficial microorganisms (bacteria and fungi), which when applied to soil, roots, or seeds enhance the availability of different nutrients to the plant because they are able to fix atmospheric nitrogen, solubilize phosphorus, and promote uptake of immobile ions and other micronutrients (Gupta et al., 2007). 

Sulfur oxidation produces substantial amounts of H2SO4. The resulting acidification can lead to solubilization of phosphorus and other mineral nutrients in soils with a generally beneficial effect on both microorganisms and plants. 

Solubilization, uptake, and precipitation of Ca and Si are directly (or at least energetically) linked to the photosynthetic and respiratory cycling of C, H, and O. Acids from nitrification and sulfur oxidation aid phosphorus mobilization photosynthesis or respiration is required for the uptake and conversion of phosphorous into high-energy phosphate. Sulfur is oxidized (with the concomitant reduction of nitrate) by Thiobacillus denitrificans, likewise, some extremely thermophilic methanogens can transfer hydrogen not only to CO2, but also to S. These are a few examples of interrelations involved in biogeochemical cycles. 

The increased concentration of such elements provokes mortality among algae, above all chlorophyceae, leading to a decrease in biomass and productivity of lakes. However, in some cases, if the acidity of the water succeeds in mobilizing phosphates, perhaps by solubilizing apatite or other phosphorus compounds, eutrophization of the water is aided. 

The range of riverine suspended particulate matter that may be solubilized once it enters the marine realm (e.g., the so-called reactive-F ) is derived from three sources. Colman and Holland (2000) estimate that 45% may be reactive, based on RSPM-P compositional data from a number of rivers and estimated burial efficiency of this material in marine sediments. Bemer and Rao (1994) and Ruttenberg and Canfield (1994) estimate that 35% and 31% of RSPM-P is released upon entering the ocean, based on comparison of RSPM-P and adjacent deltaic surface sediment phosphorus in the Amazon and Mississippi systems, respectively. Lower estimates have been published (8% Ramirez and Rose (1992) 18% Froelich (1988) 18% Compton et al. (2000). Higher estimates have also been published (69% Howarth et al. (1995). 

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