scholarly journals Preparation and studies on immobilized α-glucosidase from baker’s yeast Saccharomyces cerevisiae

2007 ◽  
Vol 72 (12) ◽  
pp. 1255-1263 ◽  
Author(s):  
Khaled Ahmed ◽  
Nenad Milosavic ◽  
Milica Popovic ◽  
Radivoje Prodanovic ◽  
Zorica Knezevic ◽  
...  

?-Glucosidase from S. cerevisiae was covalently immobilized onto Sepabeads EC-EA by the glutaraldehyde method. An analysis of the variables controlling the immobilization process is first presented and it is shown that the highest coupling of ?-glucosidase occurred within 24 h. Also, a loading of 30 mg/g support proved to be effective, resulting in a rather high activity of around 45 U g-1 with a satisfactory degree of enzyme fixed. Both free and immobilized enzymes were then characterized by determining the activity profile as a function of pH, temperature and thermal stability. The obtained immobilized preparation showed the same optimum pH, but a higher optimum temperature compared with the soluble one. In addition, the immobilized enzyme treated at 45 ?C for 1 h still retained an activity of around 20 %, whereas the free enzyme completely lost its original activity under this condition. In conclusion, the developed immobilization procedure is quite simple, easily reproducible and provides a promising solution for the application of immobilized ?-glucosidase.

2019 ◽  
pp. 1232-1239
Author(s):  
Mohammed A Alsoufi ◽  
Raghad A. Aziz

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.


2011 ◽  
Vol 8 (2) ◽  
pp. 896-902
Author(s):  
Seniwati Dali ◽  
A. B. D. Rauf Patong ◽  
M. Noor Jalaluddin ◽  
Pirman ◽  
Baharuddin Hamzah

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.


2012 ◽  
Vol 512-515 ◽  
pp. 1699-1711 ◽  
Author(s):  
Chao Fan ◽  
Ji Lie Li ◽  
Xiao Yuan Zhu ◽  
Nan Li ◽  
Wei Wang ◽  
...  

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.


2016 ◽  
Vol 41 (6) ◽  
Author(s):  
Navvabeh Salarizadeh ◽  
Sadegh Hasannia ◽  
Reza Hassan Sajedi ◽  
Navid Lamei ◽  
Afshin Mohsenifar ◽  
...  

AbstractObjective:In the present work, we have extended the study and immobilized the metalloprotease enzyme in glutaraldehyde cross-linked chitosan nanogels to scrutinize the enzyme’s features including stability over its soluble free form.Method:The immobilized metalloprotease was characterized using scanning electron microscopy (SEM), followed by Fourier transform infrared (FTIR) spectroscopy. The enzyme is optimally active at 50°C and pH range of 8.0–10.Results:Thermal stability of the enzyme enhanced when immobilized on the nanogel. After 5 min of incubation at 50°C, immobilized enzymes retained 60% of their original activity, while negligible activity (23%) was observed in the case of the free enzyme.Conclusion:The results obtained here provide a powerful demonstration of the benefits of taking the glutaraldehyde cross-linked chitosan matrices to enhance metalloprotease stability. The high stability of the immobilized enzyme serves to improve its performance for possible application on the industrial scale.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Bárbara M. Bonine ◽  
Patricia Peres Polizelli ◽  
Gustavo O. Bonilla-Rodriguez

This study reports the immobilization of a new lipase isolated from oleaginous seeds of Pachira aquatica, using beads of calcium alginate (Alg) and poly(vinyl alcohol) (PVA). We evaluated the morphology, number of cycles of reuse, optimum temperature, and temperature stability of both immobilization methods compared to the free enzyme. The immobilized enzymes were more stable than the free enzyme, keeping 60% of the original activity after 4 h at 50°C. The immobilized lipase was reused several times, with activity decreasing to approximately 50% after 5 cycles. Both the free and immobilized enzymes were found to be optimally active between 30 and 40°C.


2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
M. Pesaran ◽  
Gh. Amoabediny ◽  
F. Yazdian

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.


2011 ◽  
Vol 236-238 ◽  
pp. 1793-1798 ◽  
Author(s):  
Hua Zheng Liang ◽  
He Chen ◽  
Jian Feng Wang ◽  
Yu Lan He

Co-immobilize enzyme by cross-linking and embedding, optimize conditions for immobilizing, determinate the enzymatic properties of co-immobilized enzyme and study the methods for preparation of genipin using co-immobilized enzyme to hydrolyze geniposide. Optimized immobilizing conditions include glutaraldehyde concentration being 0.15%, cross-linking temperature being 20°C, cross-linking time being 2 hours, the activity of co-immobilized β-glucosidase and cell reaches to 65.33U/mg and the enzyme activity recovery being 52.63%. Enzymatic properties of co-immobilized enzyme are following: optimum temperature is 55°C and optimum pH is 5.0. The transformation experiments are carried out with co-immobilized enzyme. The results show that half-life of co-immobilized enzyme reaches around 40 days, higher than the normal immobilized enzyme. The conversion rate of geniposide is above 95% after 8 hours. The genipin is isolated, purified and recrystallized to reach more than 98% of purity by High Performance Liquid Chromatography. Advantages to prepare genipin using co-immobilized enzyme include low cost, high yield, environmental friendly and easy to manufacturing.


2010 ◽  
Vol 7 (1) ◽  
pp. 123-128 ◽  
Author(s):  
Yandri. Yandri ◽  
Tati Suhartati ◽  
Sutopo Hadipo Hadi

The thermal stability increase of a-amylase obtained from locale bacteria isolate Bacillus subtilis ITBCCB148 was achieved by immobilization process using an ionic exchange matrix of DEAE-Cellulose. The result showed that the immobilized enzyme has an optimum temperature of 60°C; KM 14.8 mL substrate and Vmax 42.4 U/mL. The thermal stability storage temperature of 60°C, pH 9.0 and 60 minutes demonstrated the immobilized enzyme has residual activity of 28.1%; ki = 0.0224 min.-1; and ΔGi = 103.7 kJ mol-1. Although the immobilized enzyme’s thermal stability was only increased 1.5 times, at higher temperatures, it was much more stable than the native enzyme.


2007 ◽  
Vol 13 (4) ◽  
pp. 205-210 ◽  
Author(s):  
Milena Zuza ◽  
Slavica Siler-Marinkovic ◽  
Zorica Knezevic

This paper reports the covalent immobilization of penicillin G acylase from E. coli on Sepabeads EC-EP, an epoxy-activated polymethacrylic carrier, and describes the properties of the immobilized enzyme. Due to its versatility to mediate hydrolysis of penicillins and semi-synthetic B-lactam antibiotics synthesis reactions, the selected enzyme belongs to a class of biocatalysts of great industrial interest. The immobilized enzyme was characterized in its pH and thermal stability and reaction kinetics. The immobilization of penicillin acylase resulted in a slightly different pH activity profile and temperature optima, indicating that the immobilization by this method imparted the structural and conformational stability to this enzyme. The immobilized enzyme also retained a high catalytic activity and showed the increased thermal stability compared with a free enzyme. By comparison of decimal reduction time values obtained at 50?C, it can be concluded that the immobilized enzyme was approximately 5-fold more stable than a free enzyme. The immobilization procedure developed is quite simple and easily reproduced, and provides a promising solution for the application of penicillin acylase for the purpose of 6-aminopenicillanic acid production.


2010 ◽  
Vol 8 (3) ◽  
pp. 372-376
Author(s):  
Sari Edi Cahyaningrum ◽  
Narsito Narsito ◽  
Sri Juari Santoso ◽  
Rudiana Agustini

In this study, papain was immobilized on chitosan with Mg(II) cosslinked agent. Studies on free and immobilized papain systems for determination of optimum pH, optimum temperatur, thermal stability and reusability were carried out. The results showed that free papain had optimum pH 6.5 and optimum temperature 55 °C while the immobile papain hadoptimum pH 8 and optimum temperature 80 °C. The thermal stability of the immobilized papain, relative to that of the free papain, was markedly increased. The immobilized papain can be reused for at least six times.   Keywords: papain, immobilization, chitosan


Sign in / Sign up

Export Citation Format

Share Document