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مرکز اطلاعات علمی SID1
اسکوپوس
مرکز اطلاعات علمی SID
ریسرچگیت
strs
Issue Info: 
  • Year: 

    2012
  • Volume: 

    25
  • Issue: 

    1 (TRANSACTIONS C: ASPECTS)
  • Pages: 

    1-9
Measures: 
  • Citations: 

    0
  • Views: 

    39362
  • Downloads: 

    40182
Abstract: 

Pseudomonas aeruginosa BBRC-10036 was used for lipase production. The organism secreted the enzyme extracellulary. In order to purify the enzyme, precipitation was carried out first, and then this lipase was purified by Ion Exchange Chromatography leading to 2.3-fold purification and 11.47% recovery. Lipase from P.aeruginosa was entrapped into Ca-alginate gel beads and effect of independent variables such as alginate concentration (%w/v), CaCl2 concentration (M) and enzyme load (%v/v) on IMMOBILIZATION yield and activity of immobilized enzyme were investigated. Media optimization for IMMOBILIZATION of lipase was carried out by Response Surface Methodology. The optimum conditions were: sodium alginate concentration 2.5% (w/v), calcium chloride concentration 2.5 (M) and enzyme load 50% (v/v). Under these conditions, the highest IMMOBILIZATION yield and the optimum activity of immobilized enzyme obtained were 93.65% and 2.64 unit/g (IME), respectively.

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Issue Info: 
  • Year: 

    2005
  • Volume: 

    29
  • Issue: 

    A1
  • Pages: 

    181-187
Measures: 
  • Citations: 

    0
  • Views: 

    42311
  • Downloads: 

    21247
Abstract: 

In this article, the IMMOBILIZATION of microsomal membranes on Fractosil and hexadecyl Fractosil by hydrophobic adsorption is reported. Microsomes were prepared from rat brain and the catalytic activity of antimycin A insensitive NADH-cytochrome c reductase (NCCR), one of the membrane bound enzymes in the microsomal electron transport chain, was chosen as a representative of the microsomal membrane enzymes. The effect of pH on the enzyme activity and the effect of membrane concentration on adsorption was explored. Physical adsorption on Fractosil and hexadecyl Fractosil caused stabilization when the catalytic potential of the enzyme was followed in a continuous operation. The presence of hydrophobic ligand on Fractosil caused higher stabilization of the immobilized enzyme at 25oC and 4oC, making it more useful for continuous operations. It is suggested that using supports with appropriate hydrophobic groups are useful for the IMMOBILIZATION of biologic membranes.

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Author(s): 

BAGH VAND A.

Issue Info: 
  • Year: 

    2003
  • Volume: 

    29
  • Issue: 

    31
  • Pages: 

    1-12
Measures: 
  • Citations: 

    0
  • Views: 

    688
  • Downloads: 

    249
Abstract: 

Conventional remedial technologies of excavation/retrieval, treatment, and disposal methods for contaminated groundwater are expensive, disruptive for the hydrology of ecosystem, and are of low efficiency. Thus, because of these limitations, in situ technologies have been developed as alternatives. For the treatment of groundwater contaminated with uranium pollutants such a treatment has been developed to minimize the mobility of the uranyle ion by transferring it to a stable phase via chemically or biologically induced formations. Zero valent iron reduction (ZVI) process has been known for years but has only recently been applied to clean up environmental contamination.Not knowing the mechanism of the decontamination process, different forms of ZVI- materials have been synthesized for groundwater remediation, whereas important quantities of scrap iron from the steel industries are discharged or recycled all over the world. These include carbon steel, low alloy steel, cast iron and all other iron containing alloys. The objectives of this research were as follows:1- the reduction of uranel ions by Fe0 to form the sparingly soluble U species2- UO22+ adsorption onto iron oxyhydroxide corrosion products: and3- A combination of both reduction/precipitation and adsorptionIt is important to note that these subjects have been studied regarding to laboratories tests and column studies and also the effect of different parameters such as pH.

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گارگاه ها آموزشی
Issue Info: 
  • Year: 

    2014
  • Volume: 

    8
  • Issue: 

    2
  • Pages: 

    37-45
Measures: 
  • Citations: 

    0
  • Views: 

    49440
  • Downloads: 

    15635
Abstract: 

This work reports, IMMOBILIZATION the Cobaloxime [Co (DH)2 Cl; DH, dimethylglyoximato)] onto the MCM-41. The surface of MCM- was initially functionalized with -aminopropyltrimethoxysilane and 3-pyridine. For the electrostatic IMMOBILIZATION this was reacted with Cobaloxime and IMMOBILIZATION was achieved by an electrostatic interaction between the Co Cobaloxime and the N of the pyridine and NH amine. Additional information was obtained by powder X-ray diffraction (XRD), BET, ICP and DR-UV-Vis, FT-IR spectroscopy.

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Author(s): 

SAKHAEI FARIBA | SAMSAM SHARIAT SEYED ZIYAE ALDIN

Issue Info: 
  • Year: 

    2014
  • Volume: 

    3
  • Issue: 

    SUPPL. (1)
  • Pages: 

    271-271
Measures: 
  • Citations: 

    0
  • Views: 

    82350
  • Downloads: 

    19312
Abstract: 

Lactoperoxidase (EC.1.11.1.7), an enzyme of peroxidase family, is one of the most abundant bovine milk enzymes in which enter the whey in the process of cheese production. The lactoperoxidase enzyme has been of great interest due to its valuable properties, which can be widely used in medical field as well as in food fields. Recently, some studies have revealed that thermostability of the enzyme is not appropriate to use the enzyme in industry. The purpose of the present study was to IMMOBILIZATION of lactoperoxidase onto copper nanoparticles, and compare the thermostability of the native and the immobilized enzyme. Lactoperoxidase was purified from whey, a by-product in cheese industry by cation exchange and gel filtration chromatography .Then, purified enzyme was immobilized on the surface of copper nanoparticles by the method of Link et al. The immobilized enzyme displayed a similar pH- dependence behavior and an enhanced thermostability up to 56% compared to the native enzyme. Copper nanoparticles can be considered as an appropriate support for improvement of thermostability of the peroxidase enzymes family.

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Issue Info: 
  • Year: 

    2003
  • Volume: 

    27
  • Issue: 

    A1
  • Pages: 

    0-0
Measures: 
  • Citations: 

    0
  • Views: 

    39669
  • Downloads: 

    16455
Abstract: 

In this article, the IMMOBILIZATION of submitochondrial particles to immobilize submitochnodrial particles (SMPs) on Fractosil-1000 by hydrophobic adsorption is reported. SMPs were prepared from beef liver mitochondria and the catalytic activity of succinate-cytochorome c reductase succinate cytochrome c reductase (SCR), multienzymatic complex of inner-mitochondrial membrane, was used as an example of its catalytic potential. The effects of membrane particles concentration and the pH of the buffer on adsorption of SMPs and the effects of buffers were explored. The response of free and immobilized membrane preparations to changes in pH and the stabilization of SMPs in different pH values were also followed. The results revealed that the best condition for the adsorption of SMPs was approximately 14-16 mg SMP per gram of Fractosil-1000 in MPTG buffer (containing 20 mM each of mes, pipes, trizma and glycine at pH of 7.0) at 4°C. It was also observed that IMMOBILIZATION of SMPs had no effect on the optimum pH of the enzyme (pH 7.0) in both immobilized and free forms. However, the activity profiles of free and immobilized preparations were different in acidic and basic environment

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strs
Author(s): 

RODOVA A. | FILIP J.

Issue Info: 
  • Year: 

    2015
  • Volume: 

    22
  • Issue: 

    -
  • Pages: 

    1291-1298
Measures: 
  • Citations: 

    396
  • Views: 

    18447
  • Downloads: 

    17229
Keywords: 
Abstract: 

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Author(s): 

FAWZY E.M.

Journal: 

CHEMISTRY AND ECOLOGY

Issue Info: 
  • Year: 

    2008
  • Volume: 

    24
  • Issue: 

    2
  • Pages: 

    147-156
Measures: 
  • Citations: 

    409
  • Views: 

    18258
  • Downloads: 

    19588
Keywords: 
Abstract: 

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Issue Info: 
  • Year: 

    2011
  • Volume: 

    21
  • Issue: 

    3
  • Pages: 

    75-90
Measures: 
  • Citations: 

    0
  • Views: 

    690
  • Downloads: 

    273
Abstract: 

Chemical IMMOBILIZATION is an operative approach to reduce detrimental effects of heavy metals in soils. The present study was conducted to test the usefulness of this procedure to decrease soluble and DTPA-extractable Zn in two Zn-spiked (addition of 200 mg Zn kg–1soil from zinc sulfate and incubation for two weeks at 25±1oC) acid and alkaline soils. In order to study the effect of submergence, two Zn-spiked acid and alkaline soils under two moisture conditions (field capacity [FC] and submergence [S], with and without 50 g cow manure/kg soil [M]) were incubated for one month. Results showed that S+M treatment caused a markedly decrease in soluble and DTPA-extractable Zn in both alkaline (97 and 75%, respectively) and acid (85 and 78%, respectively) soils. To evaluate the effect of phosphate amendments, 5 g P/kg soil from various sources (Ca (H2PO4)2.H20, Ca3 (PO4)2, H3PO4, K2HPO4 and KH2PO4) was added to the Zn-spiked acid soil. Results showed that the K2HPO4 treatment caused a markedly decrease in soluble Zn (88%). Neverthless DTPA-extractable Zn decreased (12.5%) in Ca3 (PO4)2 treatment. In another experiment the addition of calcium carbonate to acid soil (10 g CaCO3 kg-1 soil) caused a markedly decrease in soluble and DTPA-extractable Zn (97 and 43%, respectively).

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Issue Info: 
  • Year: 

    2016
  • Volume: 

    1
  • Issue: 

    4
  • Pages: 

    183-188
Measures: 
  • Citations: 

    0
  • Views: 

    26712
  • Downloads: 

    7233
Abstract: 

Background: Enzymes are well known as sensitive catalysts in the laboratory and industrial scale. To improve their properties and for using their significant potential in various reactions as a useful catalyst the stability of enzymes can often require improvement. Enzymes IMMOBILIZATION on solid supports such as epoxyfunctionalized ferric silica nanocomposite can be effective way to improve their characteristics.Methods: In this study silica coated magnetite nanoparticles were Functionalized with GPTSM as a linker, then IMMOBILIZATION reaction performed by using various amounts of lipase B from Candida Antarctica (CALB), for the next step IMMOBILIZATION effects on thermal stability and optimum pH were investigated in comparison with free CALB.Results: Results illustrated enzyme was successfully immobilized on nano particles and immobilized derivative retains 100% of its activity by 55oC while free CALB loss its activity at the same condition.Conclusion: IMMOBILIZATION of CALB on Fe3O4@SiO2 particles resulted in significant improvements in its characteristics such as thermal stability and methanol tolerance compared to the free CALB.

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