Presence Of Tricalcium Phosphate Research Articles

Broad-spectrum pH functional chitosan-phosphatase beads for the generation of plant-available phosphorus: utilizing the insoluble P pool.

Utilization of organic phosphates and insoluble phosphates for the gradual generation of plant-available phosphorus (P) is the only sustainable solution for P fertilization. Enzymatic conversions are one of the best sustainable routes for releasing P to soil. Phosphatase enzyme aids in solubilizing organic and insoluble phosphates to plant-available P. We herein report the preparation of highly functional chitosan beads co-immobilized with acid phosphatase and alkaline phosphatase enzymes via a glutaraldehyde linkage. The dual enzyme co-immobilized chitosan beads were characterized using Fourier-transform infrared (FTIR), thermogravimetric (TGA), and scanning electron microscopy-energy dispersive x-ray (SEM-EDX) analyses to confirm the immobilization. The co-immobilized system was found to be active for a broader pH range of ∼4-10 than the individually bound enzymes and mixed soluble enzymes. The bound matrix exhibited pH optima at 6 and 9, respectively, for acid and alkaline phosphatase and a temperature optimum at 50°C. The phosphate-solubilizing abilities of the chitosan-enzyme derivatives were examined using insoluble tri-calcium phosphate (TCP) for wide pH conditions of 5.5, 7, and 8.5 up to 25 days. The liberation of phosphate was highest (27.20mg/mL) at pH 5.5 after the defined period. The residual soil phosphatase activity was also monitored after 7days of incubation with CBE for three different soils of pH ∼5.5, 7, and 8.5. The residual phosphatase activity increased for all the soils after applying the CBE. The germination index of the Oryza sativa (rice) plant was studied using different pH buffer media upon the application of the CBE in the presence of tri-calcium phosphate as a phosphate source. Overall, the dual-enzyme co-immobilized chitosan beads were highly effective over a wide pH range for generating plant-available phosphates from insoluble phosphates. The chitosan-enzyme derivative holds the potential to be used for sustainable phosphorus fertilization with different insoluble and organic phosphorus sources.

Low velocity oxy fuel spraying of hydroxyapatite coating on a multifunctional UNS S31254 austenitic stainless steel.

Artificial material such as stainless steel (SS) is widely used for orthopaedic applications owing to its superior properties, ease of fabrication and lower cost. However, in the body environment, stainless steel can leach toxic elements such as nickel and chromium. To prevent this, a hydroxyapatite (HAp) coating having chemical characteristics very similar to the human bone was deposited on a medical-grade UNS S31254 austenitic stainless steel by a Low-velocity oxy-fuel spray gun (LVOF). The coating was characterised by using a field emission scanning electron microscope (FESEM), X-ray diffractometer (XRD) and Fourier transform infrared spectroscope (FTIR). The adhesion strength, microhardness and corrosion behaviour were studied using the Tensometre, Vickers microhardness tester and potentiodynamic polarisation with electrochemical impedance spectroscope. The bacterial adhesion and bioactivity of the coating were also evaluated. The LVOF sprayed HAp coating has shown better corrosion resistance, higher bioactivity and higher hardness than the uncoated steel. The presence of tricalcium phosphate, octa-calcium phosphate (OCP) and tetra-calcium phosphate (TTCP) was found in the coating. LVOF sprayed HAp coating is also found suitable in lowering the bacterial adhesion on the steel substrate.

Formation of a Biopolymer Nano Layer by Electrolysis

Composite nanocoatings on the surface of a titanium electrode are obtained by electrochemical reduction of macroions and fibroin nanoparticles in the presence of tricalcium phosphate. Based on the measurements, the dependence of the reduced viscosity (hуд/C) on C was constructed according to the Huggins formula hуд/C = [h] + k[h]2C (where k is a constant). For FB1 and [h] = 75 ml/g the intrinsic viscosity value [h] = 118 ml/g was found by means of С ® 0 extrazolation. The molecular masses М = 295000 for FB1 and M = 175000 for FB2 was calculated, respectively, as stated by Mark-Kuhn-Houwink equation М » ([h]/1,23*10-3)1/0,91. The studies were carried out on a specially assembled electrolysis unit using as a solvent HCOOH: Н2О (50: 50) under the influence of a direct current of 2-8 mA in a temperature range of 25-50°C. within 0.5 - 10 hours. The thickness of the nanocoatings in the range of 50 - 350 nm was controlled by changing the electrolysis time in the range of 0.5 - 10 hours. Furthermore, we have shown that the obtained samples of composite nanocoating FB are characterized by stability in the process of sterilization in ethanol at 60°C, as well as in salt-containing.

Evaluation of growth, nitrogen fixation and P-solubilizing ability of diazotrophic cyanobacteria under mineral phosphorus sources

Five cyanobacterial strains, viz. Anabaena variabilis, Nostoc muscorum, Tolypothrix tenuis, Aulosira fertilissima and Westiellopsis prolifica were utilized extracellular insoluble tricalcium phosphate (TCP) and Mussorie rock phosphate (MRP) when provided as sole P source by replacing the conventional source of P (K2HPO4) in BG-11 medium. These strains exhibited a differential response to insoluble forms of phosphorus both in terms of growth and nitrogen fixation. A. variabilis, N. muscorum and W. prolifica showed better growth in presence of TCP while T. tenuis and A. fertilissima proliferated better in presence of MRP. N. muscorum recorded maximum growth in terms of total chlorophyll content (6.21 μg/ml) in presence of TCP (20 mg P/l) followed by T. tenuis (6.10 μg/ml) in presence of MRP (20 mg P/l) after 21 days of incubation. Nitrogen fixation measured as acetylene reduction (AR) activity showed significant variation among different strains when grown at varied concentrations of TCP or MRP and time of incubation. N. muscorum showed maximum AR activity of 6.17 μmole C2H4/mg chl/h in presence of MRP (20 mg P/l) followed by A. variabilis which recorded 5.46 μmole C2H4/mg chl/h but in presence of TCP (20 mg P/l) after 28 days of incubation. In general, in all the strains tested, AR activity was more in presence of higher concentration of TCP/ MRP than their lower concentrations (10 mg P/l). In terms of P-solubilization, A. variabilis was found to be the best, showing maximum amount of available P, i.e. 0.224 μg/ml and TCP (20 mg P/l) was the best utilized source of mineral P compared to MRP.

Production of Hydroxyapatite Nanoparticles Using Tricalcium- Phosphate by Alkanindiges illinoisensis

Production of Hydroxyapatite Nanoparticles Using Tricalcium- Phosphate by Alkanindiges illinoisensis The general purpose of this study was to examine the role of urease and phosphatase in production of hydroxyapatite (HA) nanocrystal that was performed using two different media of precipitating and Pikovskaya (PVK), respectively. We evaluated properties of HA by means of X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) an equipped with energy dispersive X-ray spectroscopy (EDX). Among bacterial strains isolated from nature, only two strains C17 and C21 had the ability to produce HA nanocrystal. These strains were phosphatase-positive and produced HA only in the presence of tricalcium-phosphate as an insoluble mineral phosphorus, therefore phosphatase have a direct role in the HA production. In the other hand, none of strains which were urease-positive had any ability to produce HA, therefore urease has no role in HA production. Crystallite particle size was determined from XRD data using Scherrer formula that was sub- 25-nm. Based on data obtained, the strain C17 selected as the best HA-producing strain. The BLAST analysis showed that partial 16S rRNA sequence of this isolate is more than 99% identical of Alkanindiges illinoisensis that was deposited in GenBank with accession number JX666243. The aim of this study was to find easier and cheaper ways for HA production using tricalcium-phosphate as an inorganic phosphate instead of glycerol-2- phosphate (G-2-P) that was used by previous researchers.

Effect of Mineral Phosphate Solubilization on Biological Nitrogen Fixation by Diazotrophic Cyanobacteria

The ability of two diazotrophic cyanobacteria Westiellopsis prolifica and Anabaena variabilis were examined to solubilize extracellular insoluble tricalcium phosphate (TCP) and Mussorie rock phosphate (MRP). The two strains exhibited a differential response to insoluble forms of phosphorus used. W. prolifica showed better growth in presence of MRP while A. variabilis proliferated better in presence of TCP. Biological nitrogen fixation measured in terms of acetylene reduction (AR) activity showed significant variation among the concentrations of TCP or MRP and time of incubation. W. prolifica and A. variabilis showed maximum AR activity on 14 and 21days of incubation respectively. In general AR activity in presence of MRP was always less than that in presence of TCP at all concentrations. Among the two cyanobacteria A. variabilis was best in terms of P-solubilization and nitrogen fixation and TCP (20mgPl(-1)) was the best source of insoluble P rather than MRP or K(2)HPO(4).

The evaluation of free and encapsulated Aspergillus awamori for phosphate solubilization in fermentation and soil–plant system

Aspergillus awamori S19, a phosphate solubilizing filamentous fungi, was immobilized in Ca-alginate and agar. The immobilized microbial cells were applied in a repeated-batch fermentation process in order to test their effect on solubilization of Udaipur rock phosphate (URP) and tricalcium phosphate (TCP). Agar entrapped cells produced 106 mg l −1 whereas Ca-alginate entrapped cells produced 93 mg l −1 soluble P that was significantly higher than freely suspended cells with URP. In the presence of TCP, immobilized cells showed significantly better phosphate solubilization than free cells, viz. 340 and 345 mg l −1 in agar and Ca-alginate entrapment, respectively versus merely 291 mg l −1 with free cells. Further the immobilized cells were introduced into the soil supplemented with TCP and URP to analyze their effect on plant growth and P uptake of mung bean plants. The result showed significantly higher plant growth in the presence of fungal inoculates.

Zinc-Containing Calcium Phosphate Ceramics with a (Ca+Zn)/P Molar Ratio of 1.67

Zinc-containing calcium phosphate ceramics with a (Ca+Zn)/P molar ratio of 1.67 (ZnHAP ceramics) were synthesized to clarify the main phase for zinc release. ZnHAP ceramics with a zinc content at or more than 0.20 wt% contained zinc-containing tricalcium phosphate. The ion activity product of monophasic ZnHAP ceramic containing at or less than 0.13 wt% of zinc corresponded to that of pure HAP ceramic. The presence of tricalcium phosphate (TCP) phases was necessary condition for ZnHAP ceramics to release zinc. The coexistence of TCP phases in the ZnHAP ceramics meant that a phase with a (Ca+Zn)/P molar ratio higher than 1.67 also coexisted. Although the phase was assumed to be zinc oxide, zinc was not concentrated anywhere in the ZnHAP ceramics including grain boundaries.

Availability of supplemental amino acid-chelated trace elements in diets containing tricalcium phosphate and phytate to rainbow trout, Oncorhynchus mykiss

This study investigated the availability of amino acid-chelated trace elements to rainbow trout fed diets containing tricalcium phosphate (TCP) and phytate (PH) that are known mineral inhibitors. Six semi-purified diets were supplemented with trace elements either from the sulfate (SF, diets 1 and 2) or amino acid-chelate (AM, diets 3–6). Diets 1 (SF) and 3 (AM) contained neither TCP nor PH. Diet 4 (AMPO) included TCP while Diet 5 (AMPH) contained PH alone. Diets 2 (SF++) and 6 (AM++), on the other hand, contained both inhibitors. Rainbow trout weighing 1.6 g were fed the experimental diets three times daily to near satiation for 18 weeks. Growth, whole body mineral deposition, and enzyme activity/expression were measured after the trial. Growth of fish fed the SF++ diet was significantly lower than the rest of the groups. Whole body Cu content was significantly higher in AM groups than in SF groups with or without TCP and PH. Whole body and bone Zn contents were significantly higher in fish fed the diet containing AM alone compared to the rest. Alkaline phosphatase activity was significantly higher in fish fed the diet containing AM alone than with fish fed the SF diet with or without TCP and PH. CuZnSOD and DNA polymerase were highly expressed in the AM compared to the SF groups. The results show that availability of trace elements is significantly affected by their chemical form and that amino acid-chelates are more beneficial for rainbow trout even in the presence of TCP and PH compared to the inorganic sources tested.

Improvement in bioavailability of tricalcium phosphate to Cymbopogon martinii var. motia by rhizobacteria, AMF and Azospirillum inoculation

The interactive effects of phosphate solubilizing bacteria, N2 fixing bacteria and arbuscular mycorrhizal fungi (AMF) were studied in a low phosphate alkaline soil amended with tricalcium insoluble source of inorganic phosphate on the growth of an aromatic grass palmarosa (Cymbopogon martinii). The microbial inocula consisted of the AM fungus Glomus aggregatum, phosphate solubilizing rhizobacteria Bacillus polymyxa and N2 fixing bacteria Azospirillum brasilense. These rhizobacteria behaved as "mycorrhiza helper" and enhanced root colonization by G. aggregatum in presence of tricalcium phosphate at the rate of 200 mg kg(-1) soil (P1 level). Dual inoculation of G. aggregatum and B. polymyxa yielded 21.5 g plant dry weight (biomass), while it was 21.7 g in B. polymyxa and A. brasilense inoculated plants as compared to 14.9 g of control at the same level. Phosphate content was maximum (0.167%) in the combined treatment of G. aggregatum, B. polymyxa and A. brasilense at P1 level, however acid phosphatase activity was recorded to be 4.75 pmol mg(-1) min(-1) in G. aggregatum, B. polymyxa and A. brasilense treatment at P0 level. This study indicates that all microbes inoculated together help in the uptake of tricalcium phosphate which is otherwise not used by the plants and their addition at 200 mg kg(-1) of soil gave higher productivity to palmarosa plants.

An investigation of the dehydration of 3-oxa-, 3-thia- and 3-aza-1,5-pentanediols in the presence of tricalcium phosphate

In the presence of tricalcium phosphate, 3-oxa-, 3-aza-, and 3-thia-1, 5-pentanediols undergo intramolecular dehydration with the formation of heterocycles and also of unstable readily-polymerizing vinyl compounds. The total degree of conversion of the diols rises in the sequence diethyleneglycol <1, 5-pentanediol <diethanolamine <N-methylethanolamine <di(hydroxyethyl) sulfide. At low temperatures, the yield of cyclic product from 1, 5-pentanediol and diethyleneglycol is close to the degree of conversion of the diol, and at high temperatures it falls behind markedly. Diethanolamine, N-methyldiethanolamine, and di(hydroxyethyl) sulfide dehydrate to the corresponding six-membered oxides unselectively.

Investigation of the mechanism of vapour-phase dehydration of isopentene alcohols in the presence of acid catalysts

1. 1. The ease of dehydration of isopentene alcohols with acid catalysts decreases in the sequence 2-methyl 3-buten-2-ol>3-methyl 2-buten-1-ol>3-methyl 3-buten-1-ol The activity of catalysts in this reaction decreases in the following sequence: aluminosilicate>alumina>calcium phosphate . 2. 2. The low isoprene yield during dehydration of 3-methyl 3-buten-1-o1 in the presence of alumina and aluminosilicate is due to the cyclization of alcohol to β-methyltetrahydrofuran and subsequent splitting of oxacyclane to formaldehyde and isobutene. In the presence of tri-calcium phosphate which slightly accelerates cyclization, a high isoprene yield is obtained. 3. 3. The following reactions accompany dehydration of isopentene alcohols: isomerization of 3-methyl 2-buten-1-ol to isovaleric aldehyde, allyl re-grouping of 2-methyl 3-buten-2-ol to 3-methyl 2-buten-1-ol and 3-methyl 3-buten-1-ol and polymerization of isoprene. Alumina and aluminosilicate are more active in these reactions than calcium phosphate.

Vapor-phase hydrolysis of halobenzenes over a promoted phosphate catalyst

1. The vapor-phase hydrolysis of halobenzenes over a phosphate catalyst promoted with cupric chloride was investigated. 2. It was shown that, as in the presence of silica gel, in the presence of tricalcium phosphate the hydrolysis of chlorobenzene is promoted by cupric chloride. 3. It was found that the reactivities of halobenzenes in the investigated reaction fall in the same order as in presence of silica gel. 4. The question of the ratio between total and active surface in silica gel and phosphate catalysts was discussed. The number of active sites in the catalyst was estimated.

Kinetics of the dehydration of alcohols in presence of tricalcium phosphate

An investigation has been made into the kinetics of the dehydration in presence of tricalcium phosphate as catalyst of ethyl, n-propyl, isopropyl, n-butyl, and isobutyl alcohols. 1. It has been established that in presence of tricalcium phosphate the dehydration of alcohols proceeds in a very selective fashion, the content of unsaturated compounds in the gas being 98–99%. 2. It has been found that in presence of tricalcium phosphate secondary alcohols are the most readily dehydrated, then follow the iso-alcohols, and finally the normal alcohols. The rate of dehydration of normal alcohols falls with fall in molecular weight. 3. It has been established that when the phosphate catalyst is calcined its activity in the alcohols-dehydration reaction is greatly reduced. 4. It has been shown that when an α- orβ-hydrogen of ethanol is replaced of methyl the activation energy is lowered in a manner similar to that already observed for dehydration in presence of other catalysts. 5. It has been found that potassium carbonate, which is a promoter for the phosphate catalyst in the dehydration of formic acid, is a powerful poison for it in the dehydration of alcohols. 6. It has been shown that diethyl ether is not an intermediate product in the formation of ethylene from ethyl alcohols.