-CHYMOTRYPSIN IMMOBILIZED ENZYME: PHYSICAL, ACTIVITY & STABILITY PROPERTIES

2015 ◽  
Vol 76 (1) ◽  
Author(s):  
Mohd Hakimi Nazir ◽  
Norzita Ngadi
Keyword(s):  
Physical Properties ◽  
Immobilized Enzyme ◽  
Enzyme Stability ◽  
Sample Solution ◽  
Bet Surface Area ◽  
Adsorption Activity ◽  
Hy Zeolite ◽  
Isotherm Adsorption ◽  
The Stability ◽  
Stability Results

In this study, α-chymotrypsin enzyme was used as a substrate while micropore Y-zeolite, which is HY, USY and NaY as a support. The purpose of this study was to compare the physical properties of zeolite and immobilization of enzyme with zeolite.  The characteristics such as BET surface area, isotherm adsorption, BJH adsorption, pore size, t-plot and pore volume have been studied. Furthermore, a comparison has been conducted between immobilized and mobile enzyme for their ability to adsorb hydrolysate at λ=410 nm.  The stability of the immobilized enzyme was also determined by varying the parameters of phosphate and tris-chloride buffer and loading of sample solution. Based on the result obtained, HY zeolite has the best physical properties compared to USY and NaY zeolite.  Besides that, immobilized enzyme gave higher hydrolysate adsorption activity than the free enzyme. Stability results showed that pH of phosphate and tris-chloride buffer and amount of sample solution play an important role in obtaining the stable immobilized enzyme.   

scholarly journals Effect of Concentrated Salts Solutions on the Stability of Immobilized Enzymes: Influence of Inactivation Conditions and Immobilization Protocol

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 968
Author(s):  
Sabrina Ait Braham ◽  
El-Hocine Siar ◽  
Sara Arana-Peña ◽  
Diego Carballares ◽  
Roberto Morellon-Sterling ◽  
...  
Keyword(s):  
Immobilized Enzyme ◽  
Enzyme Stability ◽  
Immobilized Enzymes ◽  
Penicillin G ◽  
Specific Enzyme ◽  
Interfacial Activation ◽  
Agarose Beads ◽  
High Concentrations ◽  
The Stability ◽  
Universal Rule

This paper aims to investigate the effects of some salts (NaCl, (NH4)2SO4 and Na2SO4) at pH 5.0, 7.0 and 9.0 on the stability of 13 different immobilized enzymes: five lipases, three proteases, two glycosidases, and one laccase, penicillin G acylase and catalase. The enzymes were immobilized to prevent their aggregation. Lipases were immobilized via interfacial activation on octyl agarose or on glutaraldehyde-amino agarose beads, proteases on glyoxyl agarose or glutaraldehyde-amino agarose beads. The use of high concentrations of salts usually has some effects on enzyme stability, but the intensity and nature of these effects depends on the inactivation pH, nature and concentration of the salt, enzyme and immobilization protocol. The same salt can be a stabilizing or a destabilizing agent for a specific enzyme depending on its concentration, inactivation pH and immobilization protocol. Using lipases, (NH4)2SO4 generally permits the highest stabilities (although this is not a universal rule), but using the other enzymes this salt is in many instances a destabilizing agent. At pH 9.0, it is more likely to find a salt destabilizing effect than at pH 7.0. Results confirm the difficulty of foreseeing the effect of high concentrations of salts in a specific immobilized enzyme.

scholarly journals Optimization of Culture Conditions for Some Identified Fungal Species and Stability Profile of α-Galactosidase Produced

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
A. S. Chauhan ◽  
N. Srivastava ◽  
H. K. Kehri ◽  
B. Sharma
Keyword(s):  
Enzyme Activity ◽  
Guar Gum ◽  
Enzyme Stability ◽  
Culture Conditions ◽  
Fungal Species ◽  
Agricultural Products ◽  
Rhizospheric Soil ◽  
Carbon Substrates ◽  
The Stability ◽  
Stability Results

Microbial α-galactosidase preparations have implications in medicine and in the modification of various agricultural products as well. In this paper, four isolated fungal strains such as AL-3, WF-3, WP-4 and CL-4 from rhizospheric soil identified as Penicillium glabrum (AL-3), Trichoderma evansii (WF-3), Lasiodiplodia theobromae (WP-4) and Penicillium flavus (CL-4) based on their morphology and microscopic examinations, are screened for their potential towards α-galactosidases production. The culture conditions have been optimized and supplemented with specific carbon substrates (1%, w/v) by using galactose-containing polysaccharides like guar gum (GG), soya casein (SC) and wheat straw (WS). All strains significantly released galactose from GG, showing maximum production of enzyme at 7th day of incubation in rotary shaker (120 rpm) that is 190.3, 174.5, 93.9 and 28.8 U/mL, respectively, followed by SC and WS. The enzyme activity was stable up to 7days at −20°C, then after it declines. This investigation reveals that AL-3 show optimum enzyme activity in guar gum media, whereas WF-3 exhibited greater enzyme stability. Results indicated that the secretion of proteins, enzyme and the stability of enzyme activity varied not only from one strain to another but also differed in their preferences of utilization of different substrates.

Epitaxial Growth in Dislocation-Free Strained Alloy Films

2002 ◽  
Vol 715 ◽  
Author(s):  
Zhi-Feng Huang ◽  
Rashmi C. Desai
Keyword(s):  
Deposition Rate ◽  
Elastic Moduli ◽  
Composition Dependence ◽  
Critical Thickness ◽  
Lattice Misfit ◽  
Misfit Strain ◽  
Joint Stability ◽  
Alloy Films ◽  
The Stability ◽  
Stability Results

AbstractThe morphological and compositional instabilities in the heteroepitaxial strained alloy films have attracted intense interest from both experimentalists and theorists. To understand the mechanisms and properties for the generation of instabilities, we have developed a nonequilibrium, continuum model for the dislocation-free and coherent film systems. The early evolution processes of surface pro.les for both growing and postdeposition (non-growing) thin alloy films are studied through a linear stability analysis. We consider the coupling between top surface of the film and the underlying bulk, as well as the combination and interplay of different elastic effects. These e.ects are caused by filmsubstrate lattice misfit, composition dependence of film lattice constant (compositional stress), and composition dependence of both Young's and shear elastic moduli. The interplay of these factors as well as the growth temperature and deposition rate leads to rich and complicated stability results. For both the growing.lm and non-growing alloy free surface, we determine the stability conditions and diagrams for the system. These show the joint stability or instability for film morphology and compositional pro.les, as well as the asymmetry between tensile and compressive layers. The kinetic critical thickness for the onset of instability during.lm growth is also calculated, and its scaling behavior with respect to misfit strain and deposition rate determined. Our results have implications for real alloy growth systems such as SiGe and InGaAs, which agree with qualitative trends seen in recent experimental observations.

scholarly journals Analysis of dengue model with fractal-fractional Caputo–Fabrizio operator

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Fatmawati ◽  
Muhammad Altaf Khan ◽  
Cicik Alfiniyah ◽  
Ebraheem Alzahrani
Keyword(s):  
Statistical Data ◽  
Dengue Infection ◽  
Fractional Operator ◽  
Novel Approach ◽  
Reduction Number ◽  
Best Fitting ◽  
The Stability ◽  
Parameter Values ◽  
Graphical Illustration ◽  
Stability Results

AbstractIn this work, we study the dengue dynamics with fractal-factional Caputo–Fabrizio operator. We employ real statistical data of dengue infection cases of East Java, Indonesia, from 2018 and parameterize the dengue model. The estimated basic reduction number for this dataset is $\mathcal{R}_{0}\approx2.2020$ R 0 ≈ 2.2020 . We briefly show the stability results of the model for the case when the basic reproduction number is $\mathcal{R}_{0} <1$ R 0 < 1 . We apply the fractal-fractional operator in the framework of Caputo–Fabrizio to the model and present its numerical solution by using a novel approach. The parameter values estimated for the model are used to compare with fractal-fractional operator, and we suggest that the fractal-fractional operator provides the best fitting for real cases of dengue infection when varying the values of both operators’ orders. We suggest some more graphical illustration for the model variables with various orders of fractal and fractional.

The tuning effect of the electric field on the physical properties of some typical wurtzite semiconductors

2017 ◽  
Vol 31 (33) ◽  
pp. 1750310 ◽  
Author(s):  
Jia-Ning Li ◽  
San-Lue Hu ◽  
Hao-Yu Dong ◽  
Xiao-Ying Xu ◽  
Jia-Fu Wang ◽  
...  
Keyword(s):  
Electric Field ◽  
Physical Properties ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
Great Influence ◽  
Semiconductor Materials ◽  
Functional Theory ◽  
The Stability ◽  
Wurtzite Semiconductors

Under the tuning of an external electric field, the variation of the geometric structures and the band gaps of the wurtzite semiconductors ZnS, ZnO, BeO, AlN, SiC and GaN have been investigated by the first-principles method based on density functional theory. The stability, density of states, band structures and the charge distribution have been analyzed under the electric field along (001) and (00[Formula: see text]) directions. Furthermore, the corresponding results have been compared without the electric field. According to our calculation, we find that the magnitude and the direction of the electric field have a great influence on the electronic structures of the wurtzite materials we mentioned above, which induce a phase transition from semiconductor to metal under a certain electric field. Therefore, we can regulate their physical properties of this type of semiconductor materials by tuning the magnitude and the direction of the electric field.

scholarly journals Effect of Lactic Acid Content into on during Miconazole Eye Drops to be Used for Infection Preventive

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yoshimura K ◽  
Inoue Y ◽  
Koizumi A ◽  
Suzuki M ◽  
Itakura S ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Physical Properties ◽  
Acid Content ◽  
Eye Drops ◽  
Lactic Acid Content ◽  
The Stability

Purpose: The aims of this study were to prepare a 0.1% Miconazole (MCZ) eye-drop solution and to evaluate the stability and physical properties of the preparation.

scholarly journals Stabilitas Zeolit HY Hidrofobik terhadap Uji Hot Liquid Water (HLW)

2021 ◽  
Vol 10 (2) ◽  
pp. 58-62
Author(s):  
Yuni Susanti ◽  
Yeni Variyana
Keyword(s):  
Liquid Water ◽  
Raw Materials ◽  
Sodium Aluminate ◽  
Zeolite Catalysts ◽  
Wave Number ◽  
Physical Test ◽  
Hy Zeolite ◽  
Ftir Spectrometer ◽  
Two Phases ◽  
The Stability

Initially, zeolite catalysts cannot be used for reactions involving hot liquid water, so it is necessary to modify the zeolite to be stable under these conditions. The synthesis of HY and hydrophobic zeolites aimed to determine the stability of zeolite in hot liquid water (HLW). The stability of zeolite in HLW is related to zeolite hydrophobicity. In this study, the main raw materials for the synthesis of HY zeolite were sodium aluminate (NaAlO2) and Ludox HS-40 by calcining the product at 350 oC for 1 hour. Furthermore, increasing the hydrophobicity of HY zeolite was carried out by modifying the external zeolite surface using organosilanes (aminopropyltriethoxysilane). The stability of two zeolites in HLW was set at 200 oC. Zeolite analysis used physical test and Fourier Transform-Infra Red (FTIR) Spectrometer. The results of the zeolite distribution in two phases confirmed that HY zeolite was completely dispersed in the water phase, while the zeolite one was dispersed in the organic phase. Moreover, the IR spectra of HY zeolite showed that the wide peak detection at wave number 720 cm-1 for beginning to disappear. This means that the HLW condition could be damaged to the d6r unit. Another result was shown by hydrophobic zeolite spectra with a stable peak for 72 hours. This indicates that the hydrophobic zeolite has thermal stability in HLW so that it can be used in chemical reaction catalytic applications that use on phase.

scholarly journals Boundary Stabilization of a Semilinear Wave Equation with Variable Coefficients under the Time-Varying and Nonlinear Feedback

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Bei Gong ◽  
Xiaopeng Zhao
Keyword(s):  
Wave Equation ◽  
Riemannian Geometry ◽  
Nonlinear Term ◽  
Variable Coefficients ◽  
Time Varying ◽  
Nonlinear Feedback ◽  
Boundary Stabilization ◽  
Semilinear Wave Equation ◽  
The Stability ◽  
Stability Results

We study the boundary stabilization of a semilinear wave equation with variable coefficients under the time-varying and nonlinear feedback. By the Riemannian geometry methods, we obtain the stability results of the system under suitable assumptions of the bound of the time-varying term and the nonlinearity of the nonlinear term.

scholarly journals On the probabilistic stability of some functional equations

2013 ◽  
Vol 29 (1) ◽  
pp. 125-132
Author(s):  
CLAUDIA ZAHARIA ◽  
◽  
DOREL MIHET ◽  
Keyword(s):  
Fixed Point ◽  
Functional Equations ◽  
Fixed Point Theory ◽  
Point Theory ◽  
Quadratic Functional ◽  
Normed Spaces ◽  
Stability Of Functional Equations ◽  
The Stability ◽  
Stability Results

We establish stability results concerning the additive and quadratic functional equations in complete Menger ϕ-normed spaces by using fixed point theory. As particular cases, some theorems regarding the stability of functional equations in β - normed and quasi-normed spaces are obtained.

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