Carrier-Free Enzyme Immobilization by Cross-Linked Enzyme Aggregates (CLEA) Technology

Author(s):  
Faridah Yusof ◽  
Soofia Khanahmadi
2016 ◽  
Vol 88 (9) ◽  
pp. 1247-1247 ◽  
Author(s):  
R. Kloß ◽  
V. Jäger ◽  
M. Diener ◽  
U. Kruaß ◽  
M. Pohl

INEOS OPEN ◽  
2020 ◽  
Author(s):  
N. A. Samoilova ◽  

The enzyme-containing magnetic composites are presented. The magnetic matrix for enzyme immobilization is obtained by sequential application of an amine-containing polysaccharide—chitosan and a synthetic polymer—poly(ethylene-alt-maleic acid) to the magnetite microparticles to form the interpolyelectrolyte complex shell. Then, the enzyme (trypsin) is immobilized by covalent or noncovalent binding. Thus, the suggested composites can be readily obtained in the environmentally friendly manner. The enzyme capacity of the resulting composites reaches 28.0–32.6 mg/g. The maximum hydrolysis rates of the H-Val-Leu-Lys-pNA substrate provided by these composites range within 0.60·10–7–0.77·10–7 M/min.


1962 ◽  
Vol 41 (4) ◽  
pp. 584-594 ◽  
Author(s):  
Dankwart Reinwein ◽  
Erich Klein

ABSTRACT The iodine metabolism was investigated in 29 patients with euthyroid non-endemic diffuse goiter. 1 to 14 days before thyroidectomy the patients received carrier-free 131I. The chemical iodine fractions (PBI, BEI and iodide) of the thyroid and the labelled iodine compound were analyzed by means of paper- and column chromatography. In one gland the total iodine content varied only by ± 19.6% of the average, the relative shares of PBI, BEI and iodide as well as that of the iodoamino acids being equal. Monoiodotyrosine, diiodotyrosine and thyroxine were found in the thyroid homogenate without hydrolysis. The homogenate after hydrolysis contained more iodotyrosines at the expense of iodothyronines than do normal glands. 17 goiters with normal 131I-uptake showed a high total iodine content (14.2 ± 5.0 mg) whilst 9 goiters with an increased 131I-uptake had low values (3.58 ± 0.6 mg). The opposite was found for the relative shares of BEI with the chromatographically isolated iodothyronines thyroxine, triiodothyronine and an unidentified iodine compound. Goiters with »high plasma PB131I« were characterized by a faster transfer of 131I into the more heavily iodinated compounds than is found in glands with a normal hormonal secretion rate. The highest values for the iodothyronines were found in goiters with increased 131I-uptake together with a high hormonal secretion rate. From this study it appears that the changes in the iodine-poor glands are due to a defective exo- or endogenous iodine supply. The observed alterations in iodine-rich glands are probably induced by a faulty iodine utilization characterized by an incomplete iodotyrosyl-coupling defect.


2020 ◽  
Author(s):  
Jia Shen Chew ◽  
Ken Chi Lik Lee ◽  
THI THANH NHA HO

<p>Lee and coworkers offers a kind of new concept to enzyme immobilization and explores its suitability in the context of miniaturisation and high-throughput screening. Here, polystyrene-immobilized ketoreductases are compared with its non-immobilized counterparts in terms of conversion and stereoselectivity (both determined by chiral HPLC), and the study indicates that the BioBeads perform similarly (sometimes slightly more selective) which may be useful whenever defined micro-scale amounts of biocatalysts were required in high-throughput experiment settings.</p>


2019 ◽  
Vol 25 (24) ◽  
pp. 2661-2676 ◽  
Author(s):  
Sundaresan Bhavaniramya ◽  
Ramar Vanajothi ◽  
Selvaraju Vishnupriya ◽  
Kumpati Premkumar ◽  
Mohammad S. Al-Aboody ◽  
...  

Enzymes exhibit a great catalytic activity for several physiological processes. Utilization of immobilized enzymes has a great potential in several food industries due to their excellent functional properties, simple processing and cost effectiveness during the past decades. Though they have several applications, they still exhibit some challenges. To overcome the challenges, nanoparticles with their unique physicochemical properties act as very attractive carriers for enzyme immobilization. The enzyme immobilization method is not only widely used in the food industry but is also a component methodology in the pharmaceutical industry. Compared to the free enzymes, immobilized forms are more robust and resistant to environmental changes. In this method, the mobility of enzymes is artificially restricted to changing their structure and properties. Due to their sensitive nature, the classical immobilization methods are still limited as a result of the reduction of enzyme activity. In order to improve the enzyme activity and their properties, nanomaterials are used as a carrier for enzyme immobilization. Recently, much attention has been directed towards the research on the potentiality of the immobilized enzymes in the food industry. Hence, the present review emphasizes the different types of immobilization methods that is presently used in the food industry and other applications. Various types of nanomaterials such as nanofibers, nanoflowers and magnetic nanoparticles are significantly used as a support material in the immobilization methods. However, several numbers of immobilized enzymes are used in the food industries to improve the processing methods which not only reduce the production cost but also the effluents from the industry.


2019 ◽  
Vol 15 (3) ◽  
pp. 296-303 ◽  
Author(s):  
Swapnil Gaikwad ◽  
Avinash P. Ingle ◽  
Silvio Silverio da Silva ◽  
Mahendra Rai

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.


Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 581
Author(s):  
Gajanan S. Ghodake ◽  
Surendra K. Shinde ◽  
Ganesh D. Saratale ◽  
Rijuta G. Saratale ◽  
Min Kim ◽  
...  

The utilization of waste-paper-biomass for extraction of important α-cellulose biopolymer, and modification of extracted α-cellulose for application in enzyme immobilization can be extremely vital for green circular bio-economy. Thus, in this study, α-cellulose fibers were super-magnetized (Fe3O4), grafted with chitosan (CTNs), and thiol (-SH) modified for laccase immobilization. The developed material was characterized by high-resolution transmission electron microscopy (HR-TEM), HR-TEM energy dispersive X-ray spectroscopy (HR-TEM-EDS), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FT-IR) analyses. Laccase immobilized on α-Cellulose-Fe3O4-CTNs (α-Cellulose-Fe3O4-CTNs-Laccase) gave significant activity recovery (99.16%) and laccase loading potential (169.36 mg/g). The α-Cellulose-Fe3O4-CTNs-Laccase displayed excellent stabilities for temperature, pH, and storage time. The α-Cellulose-Fe3O4-CTNs-Laccase applied in repeated cycles shown remarkable consistency of activity retention for 10 cycles. After the 10th cycle, α-Cellulose-Fe3O4-CTNs possessed 80.65% relative activity. Furthermore, α-Cellulose-Fe3O4-CTNs-Laccase shown excellent degradation of pharmaceutical contaminant sulfamethoxazole (SMX). The SMX degradation by α-Cellulose-Fe3O4-CTNs-Laccase was found optimum at incubation time (20 h), pH (3), temperatures (30 °C), and shaking conditions (200 rpm). Finally, α-Cellulose-Fe3O4-CTNs-Laccase gave repeated degradation of SMX. Thus, this study presents a novel, waste-derived, highly capable, and super-magnetic nanocomposite for enzyme immobilization applications.


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