Microfluidic Reactor for Continuous Flow Biotransformations with Immobilized Enzymes: the Example of Lactose Hydrolysis by a Hyperthermophilic β_cont;-Glycoside Hydrolase

2008 ◽  
Vol 8 (1) ◽  
pp. 40-48 ◽  
Author(s):  
M. S. Thomsen ◽  
B. Nidetzky
Keyword(s):  
Continuous Flow ◽  
Glycoside Hydrolase ◽  
Immobilized Enzymes ◽  
Lactose Hydrolysis ◽  
Microfluidic Reactor

scholarly journals Continuous-Flow Photocatalytic Microfluidic-Reactor for the Treatment of Aqueous Contaminants, Simplicity, and Complexity: A Mini-Review

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1325
Author(s):  
Zhongwei Gao ◽  
Changqing Pan ◽  
Chang-Ho Choi ◽  
Chih-Hung Chang
Keyword(s):  
Continuous Flow ◽  
Lower Energy ◽  
High Efficiency ◽  
Diffusion Length ◽  
Physical Adsorption ◽  
Chemical Oxidation ◽  
Microfluidic Reactor ◽  
Global Issue ◽  
The Individual ◽  
Aqueous Contaminants

Water pollution is a growing global issue; there are many approaches to treating wastewater, including chemical coagulation, physical adsorption, and chemical oxidation. The photocatalysis process has provided a solution for removing pollutants from wastewater, where the pair of the photoelectron and hole works through an asymmetric way to degrade the contaminants under UV irradiation. This method offers an alternative route for treating the pollutant with a lower energy cost, high efficiency, and fewer byproducts. A continuous-flow microfluidic reactor has a channel size from tens to thousands of micrometers, providing uniform irradiation and short diffusion length. It can enhance the conversion efficiency of photocatalysis due to the simple spatial symmetry inside the microreactor channel and among the individual channels. In addition, the bandgap of TiO2, ZnO, or other photocatalyst nanoparticles with symmetric crystal structure can be modified through doping or embedding. In this mini-review, a review of the reported continuous-flow photocatalytic microfluidic reactor is discussed from the perspective of both microreactor design and material engineering.

Quantifying Transcription of Clinically Relevant Immobilized DNA within a Continuous Flow Microfluidic Reactor

Langmuir ◽  
2010 ◽  
Vol 26 (17) ◽  
pp. 14372-14379 ◽  
Author(s):  
Stephanie E. McCalla ◽  
Anubhav Tripathi
Keyword(s):  
Continuous Flow ◽  
Microfluidic Reactor

Immobilization of ß-galactosidase from Kluyveromyces lactis on Eupergit® C and Properties of the Biocatalyst

2012 ◽  
Vol 8 (3) ◽  
Author(s):  
Graciella da Silva Campello ◽  
Renata Aguirre Trindade ◽  
Tatiane Vieira Rêgo ◽  
Janaína Fernandes de Medeiros Burkert ◽  
Carlos André Veiga Burkert
Keyword(s):  
Thermal Stability ◽  
Ionic Strength ◽  
Batch Reactor ◽  
Kluyveromyces Lactis ◽  
Immobilized Enzymes ◽  
Maximum Activity ◽  
Lactose Hydrolysis ◽  
Substrate Affinity ◽  
Burman Design ◽  
Plackett Burman Design

Abstract The main goal of this study was to investigate the immobilization of commercial ß-galactosidase from Kluyveromyces lactis (Lactozym®) on Eupergit® C. A Plackett-Burman design was proposed. The ionic strength and pH were the variables that presented significant effect (p<0.1) on immobilization. The increase in the ionic strength from 0.1 to 1.5 M and the increase in pH from 6.6 to 7.4 represented an increase of 28.56% and a reduction of 18.19% in the immobilization yield, respectively. At 25°C, pH 6.6, ionic strength of 1.5 M, immobilization for 8 h, 1 mM of divalent magnesium ion and 0.4 mL of enzyme added, reached 85% immobilization yield. The free and immobilized enzymes were characterized. pH and temperature profiles showed maximum activity at pH 6.6 and 45°C, for both free and immobilized enzymes. There was a gain in thermal stability with enzyme immobilization and there was an increase of about four times in the half-life of the immobilized derivative at 45°C (from 0.43 h to 1.78 h). This greater thermal stability was also made clear through the calculation of thermodynamic parameters (ΔH, ΔG and ΔS). Km values, 30.33 mM and 104.00 mM for free and immobilized enzymes, respectively, represented a reduction in substrate affinity after immobilization, possibly owing to stereo-conformational factors. In a batch reactor for lactose hydrolysis from cheese whey, an increase in lactose conversion with immobilization was observed at 40°C and 45°C (90.43% and 65.36%, respectively) in relation to the free enzyme (84.17% and 39.58%, respectively).

Single- and coupled-enzyme nylon-tube reactors for plasma glucose determination with glucose oxidase and aldehyde dehydrogenase.

1980 ◽  
Vol 26 (12) ◽  
pp. 1652-1655 ◽  
Author(s):  
W Hinsch ◽  
A Antonijewić ◽  
P V Sundaram
Keyword(s):  
Glucose Oxidase ◽  
Aldehyde Dehydrogenase ◽  
Plasma Glucose ◽  
Continuous Flow ◽  
Flow System ◽  
Low Cost ◽  
Immobilized Enzymes ◽  
Glucose Determination ◽  
Nylon Tube

Abstract We describe routine methods for determining glucose in plasma with use of aldehyde dehydrogenase or glucose oxidase-aldehyde dehydrogenase immobilized in a nylon tube that is integrated into a continuous-flow system. Although the coupled-enzyme nylon-tube reactors require the presence of a third enzyme, catalase, in solution, the kinetics are not so complicated as to preclude reliable routine determination of glucose at very low cost. Precision is good, and results correlate well with those by the method involving glucose oxidase in solution. More than 3000 tests may be carried out with one reactor. The immobilized enzymes are stable for several months at 4 degrees C when not in use.

scholarly journals Novel Epoxy Activated Hydrogels for Solving Lactose Intolerance

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Magdy M. M. Elnashar ◽  
Mohamed E. Hassan
Keyword(s):  
Lactose Intolerance ◽  
Epoxy Group ◽  
Immobilized Enzymes ◽  
Aldehyde Group ◽  
Medical Problem ◽  
Enzyme Concentration ◽  
Lactose Hydrolysis ◽  
World Population ◽  
Oh Groups ◽  
Michaelis Constants

“Lactose intolerance” is a medical problem for almost 70% of the world population. Milk and dairy products contain 5–10% w/v lactose. Hydrolysis of lactose by immobilized lactase is an industrial solution. In this work, we succeeded to increase the lactase loading capacity to more than 3-fold to 36.3 U/g gel using epoxy activated hydrogels compared to 11 U/g gel using aldehyde activated carrageenan. The hydrogel’s mode of interaction was proven by FTIR, DSC, and TGA. The high activity of the epoxy group was regarded to its ability to attach to the enzyme’s –SH, –NH, and –OH groups, whereas the aldehyde group could only bind to the enzyme’s –NH2group. The optimum conditions for immobilization such as epoxy chain length and enzyme concentration have been studied. Furthermore, the optimum enzyme conditions were also deliberated and showed better stability for the immobilized enzyme and the Michaelis constants,KmandVmax, were doubled. Results revealed also that both free and immobilized enzymes reached their maximum rate of lactose conversion after 2 h, albeit, the aldehyde activated hydrogel could only reach 63% of the free enzyme. In brief, the epoxy activated hydrogels are more efficient in immobilizing more enzymes than the aldehyde activated hydrogel.

Continuous-flow analysis for glucose, triglycerides, and ATP with immobilized enzymes in tubular form.

1977 ◽  
Vol 23 (9) ◽  
pp. 1556-1562 ◽  
Author(s):  
L P León ◽  
M Sansur ◽  
L R Snyder ◽  
C Horvath
Keyword(s):  
Continuous Flow ◽  
High Speed ◽  
Colorimetric Assay ◽  
Flow Analysis ◽  
Immobilized Enzymes ◽  
Free Enzyme ◽  
Assay Sensitivity ◽  
Biochemical Analyzer ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Continuous Use

Abstract Small-bore ("Autozyme") tubes with immobilized enzymes at the inner wall have been developed and studied for application in the Technicon "SMAC" high-speed continuous-flow biochemical analyzer. Tubes coated with glucose oxidase (D-glucose:oxygen oxidoreductase, EC 1.1.3.4) have been prepared for the assay of glucose, with colorimetric assay of the hydrogen peroxide produced; tubes coated with glycerol kinase (ATP:glycerol phosphotransferase, EC 2.7.1.30) for the enzymatic assay of triglycerides; tubes coated with hexokinase (ATP:D-hexose-6-phosphotransferase, EC 2.7.1.1) and glucose-6-phosphate dehydrogenase (D-glucose-6-phosphate:NAD+ oxidoreductase EC 1.1.1.49) for the measurement of ATP, an intermediate product in assays for creatine kinase. With use of 10-15 cm lengths of Autozyme tube and SMAC hydraulics (150 samples per hour), assay sensitivity and carryover were similar to values for the corresponding free-enzyme methods. These immobilized enzymes were sufficiently stable for one to eight weeks of continuous use before replacemnt. We conclude that suitable bound-enzyme tubes can replace either single or multiple free-enzyme reagents in many continuous-flow assays at high sampling rates.

scholarly journals Chimeric Lactase Capable of Spontaneous and Strong Immobilization on Cellulose and Development of a Continuous-Flow System for Lactose Hydrolysis at High Temperatures

2010 ◽  
Vol 76 (24) ◽  
pp. 8071-8075 ◽  
Author(s):  
G. A. Velikodvorskaya ◽  
T. V. Tikhonova ◽  
I. D. Gurvits ◽  
A. S. Karyagina ◽  
N. V. Lavrova ◽  
...  
Keyword(s):  
Continuous Flow ◽  
Fusion Proteins ◽  
Flow System ◽  
Thermophilic Bacterium ◽  
Hydrolysis Rate ◽  
Lactose Hydrolysis ◽  
Lactase Activity ◽  
Thermoanaerobacter Ethanolicus ◽  
A Value ◽  
Cellulose Binding

ABSTRACT Recombinant plasmids containing fusion proteins composed of two different modules were constructed and expressed in Escherichia coli. The modules encoded the lactase LacA (LacZ) from the thermophilic bacterium Thermoanaerobacter ethanolicus and the cellulase CelD, a cellulose-binding module (CBM) from Anaerocellum thermophilum. The CelD CBM provides a spontaneous and strong sorption of the fusion proteins onto a cellulose carrier. The enzymatic activities of both the free LacA protein and LacA-CelD CBM fusion proteins immobilized onto the cellulose carrier were assessed. The LacA activity of the fusion protein was dependent upon its position with respect to the CBM. The highest level of lactase activity and stability was observed when the lactase domain was localized at its N terminus. A continuous-flow column reactor of lactase immobilized on a cellulose carrier was constructed, and its activity was assessed. The lactose hydrolysis rate for a 150 mM (5%) solution at a flow rate of 1 reactor volume per min was 75%, which is a value optimal for further whey transformation into glucose/galactose syrup.

A Novel Method for High-Throughput Reduction of Compounds through Automated Sequential Injection into a Continuous-Flow Microfluidic Reactor

2005 ◽  
Vol 24 (6) ◽  
pp. 722-727 ◽  
Author(s):  
Richard Jones ◽  
Lajos Gödörházy ◽  
Dániel Szalay ◽  
János Gerencsér ◽  
György Dormán ◽  
...  
Keyword(s):  
High Throughput ◽  
Continuous Flow ◽  
Sequential Injection ◽  
Microfluidic Reactor ◽  
Novel Method
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