scholarly journals Optimal Immobilization ofβ-Galactosidase ontoκ-Carrageenan Gel Beads Using Response Surface Methodology and Its Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Magdy M. Elnashar ◽  
Ghada E. Awad ◽  
Mohamed E. Hassan ◽  
Mohamed S. Mohy Eldin ◽  
Bakry M. Haroun ◽  
...  
Keyword(s):  
Immobilized Enzyme ◽  
Covalent Binding ◽  
Maximum Velocity ◽  
Free Enzyme ◽  
Step Method ◽  
Enzyme Form ◽  
Gel Beads ◽  
Operational Temperature ◽  
Full Factorial ◽  
Central Composite

β-Galactosidase (β-gal) was immobilized by covalent binding on novelκ-carrageenan gel beads activated by two-step method; the gel beads were soaked in polyethyleneimine followed by glutaraldehyde. 22full-factorial central composite experiment designs were employed to optimize the conditions for the maximum enzyme loading efficiency. 11.443 U of enzyme/g gel beads was achieved by soaking 40 units of enzyme with the gel beads for eight hours. Immobilization process increased the pH from 4.5 to 5.5 and operational temperature from 50 to 55°C compared to the free enzyme. The apparentKmafter immobilization was 61.6 mM compared to 22.9 mM for free enzyme. Maximum velocityVmaxwas 131.2 μmol·min−1while it was 177.1 μmol·min−1for free enzyme. The full conversion experiment showed that the immobilized enzyme form is active as that of the free enzyme as both of them reached their maximum 100% relative hydrolysis at 4 h. The reusability test proved the durability of theκ-carrageenan beads loaded withβ-galactosidase for 20 cycles with retention of 60% of the immobilized enzyme activity to be more convenient for industrial uses.

Three-phase partitioning and immobilization of Bacillus methylotrophicus Y37 cellulase on organo-bentonite and its kinetic and thermodynamic properties

Clay Minerals ◽  
2020 ◽  
Vol 55 (2) ◽  
pp. 120-131
Author(s):  
Yonca Avci Duman ◽  
A. Uğur Kaya ◽  
Çiğdem Yağci
Keyword(s):  
Immobilized Enzyme ◽  
Maximum Velocity ◽  
Catalytic Performance ◽  
Covalent Immobilization ◽  
Single Step ◽  
Free Enzyme ◽  
Phase Partitioning ◽  
Bacillus Methylotrophicus ◽  
Three Phase ◽  
First Time

AbstractIn this study, for the first time Bacillus methylotrophicus Y37 cellulase was purified and recovered in a single step by three-phase partitioning (TPP). The optimal purification parameters for TPP were 40% ammonium sulfate saturation (m/v) with a 1.0:1.0 (v/v) ratio of crude extract:t-butanol, which gave 5.8-fold purification with 155% recovery of cellulase. Non-covalent immobilization of the partitioned cellulase was performed using bentonite as a support material. The activity observed in the 20th experiment was 100%. The optimal pH values and temperatures determined for the free enzyme and the immobilized enzyme were 5.0 and 6.0 and 45°C and 50°C, respectively. The Arrhenius activation energy (Ea) of the immobilized enzyme was lower than that of the free enzyme, whereas the Michaelis–Menten constant (Km) and maximum velocity (Vm) of the immobilized enzyme increased. The turnover number (kcat) and the catalytic performance (kcat/Km) demonstrated the improved catalytic properties of the immobilized enzyme compared to the free enzyme. Immobilization of cellulase is thermodynamically preferred.

scholarly journals Immobilization of Enzymes by Polymeric Materials

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1211
Author(s):  
Xingyi Lyu ◽  
Rebekah Gonzalez ◽  
Andalwisye Horton ◽  
Tao Li
Keyword(s):  
Immobilized Enzyme ◽  
Physical Adsorption ◽  
Covalent Binding ◽  
Polymeric Materials ◽  
Immobilized Enzymes ◽  
Operational Stability ◽  
Free Enzyme ◽  
External Stimulus ◽  
Harsh Environments ◽  
Immobilization Of Enzymes

Enzymes are the highly efficient biocatalyst in modern biotechnological industries. Due to the fragile property exposed to the external stimulus, the application of enzymes is highly limited. The immobilized enzyme by polymer has become a research hotspot to empower enzymes with more extraordinary properties and broader usage. Compared with free enzyme, polymer immobilized enzymes improve thermal and operational stability in harsh environments, such as extreme pH, temperature and concentration. Furthermore, good reusability is also highly expected. The first part of this study reviews the three primary immobilization methods: physical adsorption, covalent binding and entrapment, with their advantages and drawbacks. The second part of this paper includes some polymer applications and their derivatives in the immobilization of enzymes.

scholarly journals LIPASE IMMOBILIZATION ON FIBERS GRAFTED WITH POLYGLYCIDYL METHACHRYLATE

2019 ◽  
Vol 20 (1) ◽  
pp. 12-23
Author(s):  
Maan Alkhatib ◽  
Nik Adlin Bahrudin ◽  
HAMZAH M. SALLEH ◽  
Mohamed M. E. Nasef ◽  
Teo M. Ting
Keyword(s):  
Enzyme Activity ◽  
Storage Stability ◽  
Immobilized Enzyme ◽  
Immobilized Lipase ◽  
Enzyme Concentration ◽  
Free Enzyme ◽  
Effect Of Temperature ◽  
Ph Optimum ◽  
Lipase Enzyme ◽  
Central Composite

ABSTRACT: Lipase enzyme originated from wheat germ was immobilized on nylon -6- grafted with polyglycidyl methachrylate (PGMA). The immobilization of enzyme experiments were designed and studied using face centred central composite design (FCCCD) under response surface methodology (RSM). Prior to immobilization, the polymer was activated with diethyl amine/ethanol to introduce an amine functional group to facilitate covalent bonding with the enzyme. The immobilized and free enzymes were characterized for effect of temperature and pH on enzyme activity, stability, storage and reusability as well as kinetics studies. ANOVA revealed that optimum lipase activity of 0.287 U/ml was achieved at immobilization time of 5 h, pH of 6 and 1.0 mg/ml for enzyme concentration. The optimum temperatures and pH for immobilized and free enzymes were 45 °C and 35 °C, and 8 and 7, respectively. The immobilized enzyme showed higher stability compared to free enzyme. The immobilized enzyme retained 18% of its activity after being recycled 8 times. In a storage stability test, immobilized lipase was able to retain 70% of its activity after being stored for 30 days, while free enzyme activity dropped to 15 % after 20 days of storage. ABSTRAK:Enzim Lipase telah dihasilkan daripada mikroorganisma pegun gandum di atas nilon -6- dan digraf bersama poliglisidel methakrilet (PGMA). Enzim pegun ini direka dan dikaji secara eksperimen menggunakan reka bentuk campuran pusat pada permukaan (FCCCD) di bawah kaedah tindak balas permukaan (RSM). Sebelum menjadi pegun, polimer ini telah diaktifkan dengan dietil amine/ethanol bagi menghasilkan kumpulan fungsi amine bagi membantu ikatan kovalen atom pada enzim. Enzim pegun dan bebas ini telah dikategorikan mengikut kesan enzim ke atas suhu, aktiviti enzim ke atas kesan pH, kestabilan, keboleh-simpanan dan keboleh-gunaan balik, serta ujian tindak balas kinetik. ANOVA membuktikan bahawa aktiviti optimum enzim lipase ini adalah sebanyak 0.287 U/ml telah terhasil selama 5 jam pegun, pada pH 6 dan kepekatan enzim sebanyak 1.0 mg/ml. Suhu dan pH optimum, pada enzim pegun dan enzim bebas ini adalah pada 45 °C dan 35 °C, dan pH 8 dan 7, masing-masing. Enzim pegun ini menunjukkan lebih stabil daripada enzim bebas. Enzim pegun dilihat kekal 18% daripada aktivitinya selepas 8 kali ulangan. Melalui ujian kestabilan simpanan, enzim lipase pegun dapat mengekalkan 70% daripada aktivinya selepas disimpan selama 30 hari, manakala aktiviti enzim bebas telah menurun kepada 15% selepas 20 hari dalam simpanan.

On the Preparation of Bovine α-Thrombin

1978 ◽  
Vol 39 (01) ◽  
pp. 193-200 ◽  
Author(s):  
Erwin F Workman ◽  
Roger L Lundblad
Keyword(s):  
Immobilized Enzyme ◽  
Catalytic Properties ◽  
Specific Activity ◽  
Guanidine Hydrochloride ◽  
Low Molecular Weight ◽  
Reversible Process ◽  
Gel Beads ◽  
Tissue Thromboplastin ◽  
C 50 ◽  
Hydrolysis Of

SummaryAn improved method for the preparation of bovine α-thrombin is described. The procedure involves the activation of partially purified prothrombin with tissue thromboplastin followed by chromatography on Sulfopropyl-Sephadex C-50. The purified enzyme is homogeneous on polyacrylamide discontinuous gel electrophoresis and has a specific activity toward fibrinogen of 2,200–2,700 N.I.H. U/mg. Its stability on storage in liquid media is dependent on both ionic strenght and temperature. Increasing ionic strength and decreasing temperature result in optimal stability. The denaturation of α-thrombin by guanidine hydrochloride was found to be a partially reversible process with the renatured species possessing properties similar to “aged” thrombin. In addition, the catalytic properties of a-thrombin covalently attached to agarose gel beads were also examined. The activity of the immobilized enzyme toward fibrinogen was affected to a much greater extent than was the hydrolysis of low molecular weight, synthetic substrates.

Immobilized Nanoparticles-Mediated Enzymatic Hydrolysis of Cellulose for Clean Sugar Production: A Novel Approach

2019 ◽  
Vol 15 (3) ◽  
pp. 296-303 ◽  
Author(s):  
Swapnil Gaikwad ◽  
Avinash P. Ingle ◽  
Silvio Silverio da Silva ◽  
Mahendra Rai
Keyword(s):  
Catalytic Activity ◽  
Enzymatic Hydrolysis ◽  
Immobilized Enzyme ◽  
Free Enzyme ◽  
Magnetic Nanomaterials ◽  
Sugar Production ◽  
Cellulase Enzyme ◽  
Enzymatic Hydrolysis Of Cellulose ◽  
Hydrolysis Of Cellulose ◽  
Hydrolysis Of

Background: Enzymatic hydrolysis of cellulose is an expensive approach due to the high cost of an enzyme involved in the process. The goal of the current study was to apply magnetic nanomaterials as a support for immobilization of enzyme, which helps in the repeated use of immobilized enzyme for hydrolysis to make the process cost-effective. In addition, it will also provide stability to enzyme and increase its catalytic activity. Objective: The main aim of the present study is to immobilize cellulase enzyme on Magnetic Nanoparticles (MNPs) in order to enable the enzyme to be re-used for clean sugar production from cellulose. Methods: MNPs were synthesized using chemical precipitation methods and characterized by different techniques. Further, cellulase enzyme was immobilized on MNPs and efficacy of free and immobilized cellulase for hydrolysis of cellulose was evaluated. Results: Enzymatic hydrolysis of cellulose by immobilized enzyme showed enhanced catalytic activity after 48 hours compared to free enzyme. In first cycle of hydrolysis, immobilized enzyme hydrolyzed the cellulose and produced 19.5 ± 0.15 gm/L of glucose after 48 hours. On the contrary, free enzyme produced only 13.7 ± 0.25 gm/L of glucose in 48 hours. Immobilized enzyme maintained its stability and produced 6.15 ± 0.15 and 3.03 ± 0.25 gm/L of glucose in second and third cycle, respectively after 48 hours. Conclusion: This study will be very useful for sugar production because of enzyme binding efficiency and admirable reusability of immobilized enzyme, which leads to the significant increase in production of sugar from cellulosic materials.

scholarly journals Efficient Congo Red Removal Using Porous Cellulose/Gelatin/Sepiolite Gel Beads: Assembly, Characterization, and Adsorption Mechanism

Polymers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 3890
Author(s):  
Chenlu Jiao ◽  
Die Liu ◽  
Nana Wei ◽  
Jiannan Gao ◽  
Fan Fu ◽  
...  
Keyword(s):  
Congo Red ◽  
Adsorption Mechanism ◽  
Batch Adsorption ◽  
Order Kinetic ◽  
Dye Wastewater ◽  
Step Method ◽  
Gel Beads ◽  
Order Kinetic Model ◽  
Pseudo Second Order ◽  
Highly Porous

Porous sustainable cellulose/gelatin/sepiolite gel beads were fabricated via an efficient ‘hydrophilic assembly–floating droplet’ two-step method to remove Congo red (CR) from wastewater. The beads comprised microcrystalline cellulose and gelatin, forming a dual network framework, and sepiolite, which acted as a functional component to reinforce the network. The as-prepared gel beads were characterized using FTIR, SEM, XRD, and TGA, with the results indicating a highly porous structure that was also thermally stable. A batch adsorption experiment for CR was performed and evaluated as a function of pH, sepiolite addition, contact time, temperature, and initial concentration. The kinetics and isotherm data obtained were in agreement with the pseudo-second-order kinetic model and the Langmuir isotherm, with a maximum monolayer capacity of 279.3 mg·g−1 for CR at 303 K. Moreover, thermodynamic analysis demonstrated the spontaneous and endothermic nature of the dye uptake. Importantly, even when subjected to five regeneration cycles, the gel beads retained 87% of their original adsorption value, suggesting their suitability as an efficient and reusable material for dye wastewater treatments.

Immobilization and some application of α-amylase purified from Rhizoctonia solani AG-4 strain ZB-34

2019 ◽  
Vol 44 (3) ◽  
pp. 397-407
Author(s):  
Umit Uzun ◽  
Melike Yildirim Akatin
Keyword(s):  
Solid State ◽  
Rhizoctonia Solani ◽  
Apple Juice ◽  
Immobilized Enzyme ◽  
Tap Water ◽  
Covalent Binding ◽  
Immobilized Enzymes ◽  
Potential Applications ◽  
Alginate Immobilization ◽  
Ca Alginate

Abstract Background Aim of the study was to immobilize the α-amylase produced earlier from the mesophilic fungus Rhizoctonia solani AG-4 strain ZB-34 by solid-state fermentation and investigate the suitability of immobilized enzymes for some industries. Materials and methods A novel α-amylase from R. solani AG-4 strain ZB-34 was immobilized in chitosan by covalent binding and Ca-alginate by entrapment. Results The efficiency of chitosan and Ca-alginate immobilization was 67.9% and 59.6%, respectively. The immobilized enzymes showed the highest activity in the presence of starch. Optimum values for chitosan and Ca-alginate immobilized enzymes were pH 4.50 and 40°C and pH 5.50 and 60°C, respectively. It was found that immobilized enzymes were highly stable in terms of thermal and pH stabilities. When the chitosan immobilized enzyme was used with detergents, chocolate stains on dirty laundry was better cleaned. Chitosan immobilized R. solani AG-4 strain ZB-34 α-amylase was found to have a higher desizing effect at 40°C in tap water. As a result of Ca-alginate immobilization, the enzyme clarified apple juice more than the free enzyme. Conclusion The results showed that immobilized enzymes might have potential applications in industry. This is the first report immobilizing an α-amylase produced from the fungus R. solani.

Mechanisms of inhibition of adenine phosphoribosyltransferase by adenine nucleosides and nucleotides

1970 ◽  
Vol 48 (5) ◽  
pp. 573-579 ◽  
Author(s):  
J. Frank Henderson ◽  
R. E. A. Gadd ◽  
H. M. Palser ◽  
M. Hori
Keyword(s):  
Adenosine Triphosphate ◽  
Kinetic Studies ◽  
Adenosine Diphosphate ◽  
Free Enzyme ◽  
Adenine Phosphoribosyltransferase ◽  
Enzyme Form

Kinetic studies of the inhibition of adenine phosphoribosyltransferase by adenine 6′-deoxyallofuranoside and 2′-deoxyadenylate indicate that both compounds bind to free enzyme and to the enzyme–phosphoribosylpyrophosphate complex, although they bind with different relative affinities to each enzyme form. The sites to which these inhibitors bind appear to be different from those to which substrates and products bind. Kinetic and physical studies show that adenosine diphosphate and adenosine triphosphate also bind to several enzyme forms, and that their mechanisms of inhibition of this enzyme are complex.

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