scholarly journals Encapsulation of HRP Enzyme onto a Magnetic Fe3O4 Np–PMMA Film via Casting with Sustainable Biocatalytic Activity

Catalysts ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 181 ◽  
Author(s):  
Wesam H. Abdulaal ◽  
Yaaser Q. Almulaiky ◽  
Reda M. El-Shishtawy
Keyword(s):  
Metal Ions ◽  
Immobilized Enzyme ◽  
Pmma Film ◽  
Optimum Temperature ◽  
Initial Activity ◽  
Casting Method ◽  
Ph Optimum ◽  
Optimum Ph ◽  
Triton X ◽  
Enzyme Changes

Horseradish peroxidase (HRP) enzyme was effectively encapsulated onto an Fe3O4 nanoparticle–polymethyl methacrylate (PMMA) film via the casting method. The HRP was immobilized on the 0.5% Fe3O4Np–PMMA film and characterized by Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Moreover, the reusability, thermal stability, optimum pH, optimum temperature, the influence of metal ions, and the effects of detergent and organic solvent were investigated. After optimizing the immobilization conditions, the highest efficiency of the immobilized enzyme was 88.4% using 0.5% Fe3O4Np–PMMA. The reusability of the immobilized HRP activity was 78.5% of its initial activity after being repeatedly used for 10 cycles. When comparing the free and immobilized forms of the HRP enzyme, changes in the optimum temperature and optimum pH from 30 to 40 °C and 7.0 to 7.5, respectively, were observed. The Km and Vmax for the immobilized HRP were estimated to be 41 mM, 0.89 U/mL for guaiacol and 5.84 mM, 0.66 U/mL for H2O2, respectively. The high stability of the immobilized HRP enzyme was obtained using metal ions, a high urea concentration, isopropanol, and Triton X-100. In conclusion, the applicability of immobilized HRP involves the removal of phenol in the presence of hydrogen peroxide, therefore, it could be a potential catalyst for the removal of wastewater aromatic pollutants.

scholarly journals Immobilization of alpha-amylase produced by Bacillus circulans GRS 313

2003 ◽  
Vol 46 (2) ◽  
pp. 167-176 ◽  
Author(s):  
Gargi Dey ◽  
Singh Bhupinder ◽  
Rintu Banerjee
Keyword(s):  
Calcium Alginate ◽  
Immobilized Enzyme ◽  
Fold Increase ◽  
Alginate Beads ◽  
Hydrolysis Kinetics ◽  
Initial Activity ◽  
Reaction Conditions ◽  
Bead Size ◽  
Optimum Ph ◽  
Optimum Ph And Temperature

A maltooligosaccharide-forming amylase from B circulans GRS 313 was immobilized by entrapment in calcium alginate beads. The immobilized activity was affected by the size of the bead and bead size of 2mm was found to be most effective for hydrolysis. Kinetics constants, Km and Vmax were estimated and were found to be affected by the bead size. The catalytic activity of the enzyme was studied in presence of various starchy residues and metal ions. HgCl2, CuSO4 and FeCl3 caused inhibition of the enzyme. The reaction conditions, pH and temperature, was optimized using response surface methodology. At the optimum pH and temperature of 4.9 and 57ºC, the apparent activity was 25.6U/g of beads, resulting in almost 2-fold increase in activity. The immobilized enzyme showed a high operational stability by retaining almost 85% of the initial activity after seventh use.

scholarly journals Production of Aspartame by Immobilized Thermolysin

2019 ◽  
pp. 1232-1239
Author(s):  
Mohammed A Alsoufi ◽  
Raghad A. Aziz
Keyword(s):  
Reaction Time ◽  
Immobilized Enzyme ◽  
Bentonite Clay ◽  
Optimum Temperature ◽  
Initial Activity ◽  
Reaction Conditions ◽  
Original Activity ◽  
Ph Profile ◽  
Full Activity ◽  
Main Activity

The aim of this study was the production of aspartame by using immobilized thermolysin in bentonite clay. The yield of immobilized thermolysin in bentonite was 92% of the original enzyme amount. pH profile of free and immobilized enzyme was 7.0 and 7.5 respectively which was stable at 6.5-9.0 for 30min. The optimum temperature of both enzymes was 50°C, while they were stable at 65°C for 30min. however, they lost 52.73 and 61.72% from its main activity at 80°C respectively. Immobilized thermolysin has retained all activity within 27 days, but it kept 68.27% of initial activity when stored for 60 days at 4°C whereas, it retained a full activity after 20 continue usage. In addition, it retained 86.53% of its original activity after 30 continuing usages. The yield of produced aspartame was increased with reaction time; it was 9% after 1h and increased gradually to 100% after 10h at reaction conditions.

scholarly journals Immobilization of Isolated Lipase From Moldy Copra(Aspergillus Oryzae)

2011 ◽  
Vol 8 (2) ◽  
pp. 896-902
Author(s):  
Seniwati Dali ◽  
A. B. D. Rauf Patong ◽  
M. Noor Jalaluddin ◽  
Pirman ◽  
Baharuddin Hamzah
Keyword(s):  
Thermal Stability ◽  
Aspergillus Oryzae ◽  
Immobilized Lipase ◽  
Optimum Temperature ◽  
Adsorption Method ◽  
Ph Optimum ◽  
Optimum Ph ◽  
Recovery Technique ◽  
Free Lipase

Enzyme immobilization is a recovery technique that has been studied in several years, using support as a media to help enzyme dissolutions to the reaction substrate. Immobilization method used in this study was adsorption method, using specific lipase fromAspergillus oryzae. Lipase was partially purified from the culture supernatant ofAspergillus oryzae. Enzyme was immobilized by adsorbed on silica gel. Studies on free and immobilized lipase systems for determination of optimum pH, optimum temperature, thermal stability and reusability were carried out. The results showed that free lipase had optimum pH 8,2 and optimum temperature 35 °C while the immobilized lipase had optimum 8,2 and optimum temperature 45 °C. The thermal stability of the immobilized lipase, relative to that of the free lipase, was markedly increased. The immobilized lipase can be reused for at least six times.

scholarly journals Covalent immobilization of an alkaline protease from Bacillus licheniformis

2018 ◽  
Vol 43 (6) ◽  
pp. 595-604
Author(s):  
Yakup Aslan ◽  
Derya Ömerosmanoğlu ◽  
Eda Öndül Koç
Keyword(s):  
Bacillus Licheniformis ◽  
Immobilized Enzyme ◽  
Milk Proteins ◽  
Covalent Immobilization ◽  
Initial Activity ◽  
Optimum Conditions ◽  
Continuous Processes ◽  
Operational Conditions ◽  
Optimum Ph ◽  
Soluble Enzymes

Abstract Objective Since the soluble enzymes can not be used in repeated reactions and are not stable in operational conditions and not suitable for continuous processes, this study aimed the covalent immobilization of Bacillus licheniformis protease (BLP) onto Eupergit CM. Methods Optimum conditions for immobilization were determined by changing the conditions individually. The proteins and L-tyrosine were determined by UV/VIS spectrophotometer. Results The immobilization resulted in 100% immobilization and 107.7% activity yields. The optimum pH (7–8) and the optimum temperature (70°C) have not changed after immobilization. The Km values for free and immobilized enzyme were 26.53 and 37.59 g/L, while the Vmax values were 2.84 and 3.31 g L-Tyrosine/L·min, respectively. The immobilized enzyme has not lost its initial activity during the repeated 20 uses and 20 days of storage. The milk proteins were hydrolyzed in 2 h by using immobilized enzyme. The pH of the milk dropped from 6.89 to 6.53, the color was clearer but there was no change in the smell or the taste. Conclusion Consequently, it can be said that the immobilized BLP obtained can be used for industrial purposes.

Studies on Immobilization of Penicillin G Acylase to Epoxy Resin

2012 ◽  
Vol 512-515 ◽  
pp. 1699-1711 ◽  
Author(s):  
Chao Fan ◽  
Ji Lie Li ◽  
Xiao Yuan Zhu ◽  
Nan Li ◽  
Wei Wang ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Immobilized Enzyme ◽  
Continuous Operation ◽  
Penicillin G Acylase ◽  
Penicillin G ◽  
Process Conditions ◽  
Optimal Conditions ◽  
Optimum Temperature ◽  
Optimum Ph ◽  
Operation Stability

The process conditions of immobilizing penicillin G acylase(PGA) by epoxy resin were studied. This experiment used the Box-Behnken experimental design and response surface methodology(RSM) to optimize the conditions of immobilizing PGA by epoxy resin. The results showed the best process conditions were pH 8.1, temperature 29°C, carrier of epoxy resin 1g and reaction time 24 h. On these conditions, the activity of the immobilized enzyme was 365.76 U g-1, activity recovery rate was 62.82%. The characteristics of the immobilized PGA under optimal conditions had been measured and found that the optimum pH of immobilized enzyme was 9.0, the optimum temperature was 60°C. It has better continuous operation stability.

α-Amylase Aspergillus oryzae Immobilized on Modified Expanded Perlite

2014 ◽  
Vol 12 (1) ◽  
pp. 587-596 ◽  
Author(s):  
J. Rodriguez ◽  
F. Soria ◽  
H. Geronazzo ◽  
H. Destefanis
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Aspergillus Oryzae ◽  
Immobilized Enzyme ◽  
Maximum Activity ◽  
Free Enzyme ◽  
Expanded Perlite ◽  
Initial Activity ◽  
Optimum Ph ◽  
Scanning Electron

Abstract The α-amylase from Aspergillus oryzae was immobilized covalently onto expanded perlite (EP) and modified EP by treatment with TiO2 (EP-TiO2), dye HE3B (EP-HE3B) polyethylene terephthalate (PET)-hydrazide (EP-PET) and magnetite (EP-magnetite). The modified EP was characterized using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The supports were functionalized with aminopropyltriethoxysilane (APTES) and glutaraldehyde (GA). The optimum pH for free and immobilized α-amylase was 5.5. Temperature of maximum activity for free enzyme and immobilized enzyme on EP-HE3B was 50°C. The immobilized enzyme in EP-APTES this value was 55°C. The immobilized α-amylase in EP-APTES and EP-HE3B-APTES exhibited better thermostability than free enzyme. The immobilized derivatives showed moderate operational stability by retaining 50% of initial activity after seven successive reuses.

STUDIES ON 17β-HYDROXYSTEROID DEHYDROGENASE IN HUMAN ENDOMETRIUM AND ENDOMETRIAL CARCINOMA

1975 ◽  
Vol 80 (2) ◽  
pp. 355-364 ◽  
Author(s):  
K. Pollow ◽  
H. Lübbert ◽  
B. Pollow
Keyword(s):  
Endometrial Carcinoma ◽  
Ammonium Sulphate ◽  
Isoelectric Focusing ◽  
Hydroxysteroid Dehydrogenase ◽  
Maximal Velocity ◽  
Optimum Temperature ◽  
Ammonium Sulphate Precipitation ◽  
Optimum Ph ◽  
Triton X ◽  
Secretory Endometrium

ABSTRACT Microsomal 17β-hydroxysteroid dehydrogenase obtained from the human secretory endometrium (17β-HSD) was solubilized with triton X-100. A 4-fold purification was achieved by ammonium sulphate precipitation and isoelectric focusing. In the presence of glycerol the partially purified enzyme was stable at 4°C for at least 48 h. Using crude microsomes, the conversion of oestradiol to oestrone was linear with time and with the concentration of protein. The optimum temperature was approximately 40°C and the optimum pH 9.4. For the reduction of oestrone the optimum pH was 6.5. With NAD, oestradiol was oxidized approximately three times more rapidly than with NADP. Km-values for oestradiol were nearly the same in endometrial carcinoma and in proliferative and secretory endometrium (i. e. approximately 3 × 10−6 m). The maximal velocity was highest in secretory endometrium. Testosterone and androstenedione could also serve as substrates but they were interconverted more slowly than oestradiol and oestrone. Sulphhydryl groups were shown to be essential for catalysis.

scholarly journals SEMI PURIFIKASI DAN KARAKTERISASI ENZIM PROTEASE Bacillus sp.

2007 ◽  
Vol 13 (1) ◽  
pp. 51-56 ◽  
Author(s):  
Elidar Naiola ◽  
Nunuk Widhyastuti
Keyword(s):  
Metal Ions ◽  
Gel Filtration ◽  
Liquid Waste ◽  
Enzyme Reaction ◽  
Inhibitory Effect ◽  
Crude Enzyme ◽  
Bacillus Sp ◽  
Optimum Temperature ◽  
Optimum Ph ◽  
Specific Activities

The aim of the research was to find the partial purified of enzyme protease from Bacillus sp. The crude enzyme of protease was produce in rice brand medium (100 gram of rice brand in a liter tofu liquid waste). The enzyme was semi-purified by the procedure of precipitation using ethanol in different percentages of saturation, gel filtration using Sephadex G 100 and Ion Exchanged Chromatography using DEAE Sephadex A50. Specific activities of the enzyme during purification were 5.71 U/mg (crude enzyme); 6.75 U/mg (ethanol precipitations); 37.16 U/mg (gel filtration) and 43.02 U/mg (Ion Exchanged Chromatography). The optimum temperature for enzyme reaction was 45–50 °C, while the optimum pH was 7.0–8.0. Protease was relatively stable after heating until 37–50 °C for 60 minutes. Metal ions had different effects to the enzyme. CaCl2, FeCl3, MnCl2, ZnCl2 and MgCl2 increased enzyme activity, CdCl2 and HgCl2 gave an inhibitory effect, and another of metal ions had no effects to the enzyme.

scholarly journals Effect of Cultivation Time and Medium Condition in Production of Bacterial Cellulose Nanofiber for Urease Immobilization

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
M. Pesaran ◽  
Gh. Amoabediny ◽  
F. Yazdian
Keyword(s):  
Bacterial Cellulose ◽  
Immobilized Enzyme ◽  
Cellulose Nanofibers ◽  
Immobilized Enzymes ◽  
Cellulose Nanofiber ◽  
Initial Activity ◽  
Enzyme Adsorption ◽  
Cultivation Medium ◽  
Optimum Ph ◽  
Urease Immobilization

A new nanoporous biomatrix originated from bacterial resources has been chosen for urease immobilization. Urease has been immobilized on synthesized bacterial cellulose nanofiber since this enzyme has a key role in nitrogen metabolism.Gluconacetobacter xylinumATCC 10245 has been cultivated for synthesis of a nanofiber with the diameter of 30–70 nm. Different cultivation processes in the aspect of time and cultivation medium conditions were chosen to study the performance of immobilized enzyme on four types of bacterial cellulose nanofibers (BCNs). Urease immobilization into the nanofiber has been done in two steps: enzyme adsorption and glutaraldehyde cross-linking. The results showed that the immobilized enzymes were relatively active and highly stable compared to the control samples of free enzymes. Optimum pH was obtained 6.5 and 7 for different synthesized BCNs, while the optimum temperature for immobilized urease was 50°C. Finding of the current experiment illustrated that the immobilized enzyme in optimum condition lost its initial activity by 41% after 15 weeks.

scholarly journals Immobilization of Catalase on Chitosan/ZnO and Chitosan/ZnO/Fe2O3 Nanocomposites: A Comparative Study

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 820
Author(s):  
Reda M. El-Shishtawy ◽  
Nahed S. E. Ahmed ◽  
Yaaser Q. Almulaiky
Keyword(s):  
Half Life ◽  
Immobilized Enzyme ◽  
Enzyme Stability ◽  
Catalytic Performance ◽  
Free Enzyme ◽  
Initial Activity ◽  
Reaction Systems ◽  
Optimum Ph ◽  
Immobilized Catalase ◽  
System Properties

The strong catalytic performance, eco-friendly reaction systems, and selectivity of enzyme-based biocatalysts are extremely interesting. Immobilization has been shown to be a good way to improve enzyme stability and recyclability. Chitosan-incorporated metal oxides, among other support matrices, are an intriguing class of support matrices for the immobilization of various enzymes. Herein, the cross-linked chitosan/zinc oxide nanocomposite (CS/ZnO) was synthesized and further improved by adding iron oxide (Fe2O3) nanoparticles. The final cross-linked CS/ZnO/Fe2O3 nanocomposite was used as an immobilized support for catalase and is characterized by SEM, EDS, and FTIR. The nanocomposite CS/ZnO/Fe2O3 enhanced the biocompatibility and immobilized system properties. CS/ZnO/Fe2O3 achieved a higher immobilization yield (84.32%) than CS/ZnO (37%). After 10 repeated cycles, the remaining immobilized catalase activity of CS/ZnO and CS/ZnO/Fe2O3 was 14% and 45%, respectively. After 60 days of storage at 4 °C, the remaining activity of immobilized enzyme onto CS/ZnO and CS/ZnO/Fe2O3 was found to be 32% and 47% of its initial activity. The optimum temperature was noticed to be broad at 25–30 °C for the immobilized enzyme and 25 °C for the free enzyme. Compared with the free enzyme optimum pH (7.0), the optimum pH for the immobilized enzyme was 7.5. The Km and Vmax values for the free and immobilized enzyme on CS/ZnO, and the immobilized enzyme on CS/ZnO/Fe2O3, were found to be 91.28, 225.17, and 221.59 mM, and 10.45, 15.87, and 19.92 µmole ml−1, respectively. Catalase immobilization on CS/ZnO and CS/ZnO/Fe2O3 offers better stability than free catalase due to the enzyme’s half-life. The half-life of immobilized catalase on CS/ZnO/Fe2O3 was between 31.5 and 693.2 min.

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