scholarly journals Towards a Novel Computer-Aided Optimization of Microreactors: Techno-Economic Evaluation of an Immobilized Enzyme System

Symmetry ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 524
Author(s):  
Philip Pietrek ◽  
Manfred Kraut ◽  
Roland Dittmeyer
Keyword(s):  
Magnetic Beads ◽  
Glucose Dehydrogenase ◽  
Packed Bed ◽  
Detailed Knowledge ◽  
Reaction Conditions ◽  
Flow Reactors ◽  
Continuous Flow Reactors ◽  
Enzyme Cascades ◽  
And Control ◽  
Physical And Chemical

Immobilized multi-enzyme cascades are increasingly used in microfluidic devices. In particular, their application in continuous flow reactors shows great potential, utilizing the benefits of reusability and control of the reaction conditions. However, capitalizing on this potential is challenging and requires detailed knowledge of the investigated system. Here, we show the application of computational methods for optimization with multi-level reactor design (MLRD) methodology based on the underlying physical and chemical processes. We optimize a stereoselective reduction of a diketone catalyzed by ketoreductase (Gre2) and Nicotinamidadenindinukleotidphosphat (NADPH) cofactor regeneration with glucose dehydrogenase (GDH). Both enzymes are separately immobilized on magnetic beads forming a packed bed within the microreactor. We derive optimal reactor feed concentrations and enzyme ratios for enhanced performance and a basic economic model in order to maximize the techno-economic performance (TEP) for the first reduction of 5-nitrononane-2,8-dione.

scholarly journals Enzymatic Bioreactors: An Electrochemical Perspective

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1232
Author(s):  
Simin Arshi ◽  
Mehran Nozari-Asbemarz ◽  
Edmond Magner
Keyword(s):  
Direct Electron Transfer ◽  
High Surface ◽  
High Surface Area ◽  
Enzyme Engineering ◽  
Future Perspective ◽  
Enzymatic System ◽  
Reaction Conditions ◽  
Flow Reactors ◽  
Recent Developments ◽  
Enzyme Cascades

Biocatalysts provide a number of advantages such as high selectivity, the ability to operate under mild reaction conditions and availability from renewable resources that are of interest in the development of bioreactors for applications in the pharmaceutical and other sectors. The use of oxidoreductases in biocatalytic reactors is primarily focused on the use of NAD(P)-dependent enzymes, with the recycling of the cofactor occurring via an additional enzymatic system. The use of electrochemically based systems has been limited. This review focuses on the development of electrochemically based biocatalytic reactors. The mechanisms of mediated and direct electron transfer together with methods of immobilising enzymes are briefly reviewed. The use of electrochemically based batch and flow reactors is reviewed in detail with a focus on recent developments in the use of high surface area electrodes, enzyme engineering and enzyme cascades. A future perspective on electrochemically based bioreactors is presented.

Recent Advances in Photodecarboxylations Involving Phthalimides

2018 ◽  
Vol 71 (9) ◽  
pp. 634 ◽  
Author(s):  
Saira Mumtaz ◽  
Mark J. Robertson ◽  
Michael Oelgemöller
Keyword(s):  
Electrochemical Properties ◽  
Continuous Flow ◽  
Coupling Reactions ◽  
Falling Film ◽  
Macrocyclic Compounds ◽  
Reaction Conditions ◽  
Flow Reactors ◽  
Alkyl Radicals ◽  
Highly Efficient ◽  
Continuous Flow Reactors

Owing to their favourable photophysical and electrochemical properties, phthalimides undergo a variety of highly efficient photodecarboxylation reactions. These transformations have been applied to the synthesis of macrocyclic compounds as well as bioactive addition adducts. N-Acetoxyphthalimides are versatile precursors to imidyl and alkyl radicals through photodecarboxylation and have subsequently been used for a variety of coupling reactions. The generally mild reaction conditions make these reactions attractive for green chemical applications. The process protocols were successfully transferred to novel photoreactor devices, among these falling film or continuous flow reactors.

Continuous flow reactors: a perspective

2012 ◽  
Vol 14 (1) ◽  
pp. 38-54 ◽  
Author(s):  
Charlotte Wiles ◽  
Paul Watts
Keyword(s):  
Continuous Flow ◽  
Flow Reactors ◽  
Continuous Flow Reactors

Menadione nicotinamide bisulphite as a source of vitamin K and niacin activities for the growing pig

2000 ◽  
Vol 71 (1) ◽  
pp. 111-117 ◽  
Author(s):  
M. Marchetti ◽  
M. Tassinari ◽  
S. Marchetti
Keyword(s):  
Vitamin K ◽  
Control Diet ◽  
Live Weight ◽  
Organic Salt ◽  
Free Form ◽  
Food Supplementation ◽  
Sodium Bisulphite ◽  
Chemical Factors ◽  
And Control ◽  
Physical And Chemical

AbstractWhen compared with other menadione derivatives such as menadione sodium bisulphite (MSB), menadione nicotinamide bisulphite (MNB), an organic salt combining menadione and nicotinamide, shows better stability towards physical and chemical factors once it is added to pre-mixes or foods. The present work evaluates the bioavailability of the two vitamins present in this compound and toxicity in the pig. To assess vitamin bioavailability, pigs were given small amounts of food containing MNB or equivalent amounts of MSB and nicotinamide in the free form. Menadione and nicotinamide concentrations in blood samples drawn at set times after the diets were given did not reveal any significant differences between the two modes of administration. Haematic levels of both vitamins in animals receiving MNB, or MSB and nicotinamide, were after 2, 4, 8 and 12 h higher (P < 0·001) than those of untreated animals. The tolerance level to MNB was evaluated in pigs given diets containing graded amounts of MNB (100, 500, 2500 mg/kg) for 28 days. No significant (P > 0·05) differences were recorded in live weight, food intake and gain/food ratio in pigs given these diets when compared with those given an unsupplemented diet. Haemoglobin and bilirubin levels did not differ between animals given various amounts of MNB and control animals. Plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities in pigs given 100 mg/kg of MNB did not show significant differences when compared with those observed in pigs given an unsupplemented control diet. In pigs on the diets supplemented with 500 and 2500 mg/kg of MNB there was a significant increase in the two enzymatic activities as compared with controls (P < 0·001 and P < 0·01). In the case of ALT this had disappeared by 28 weeks. MNB is a good source of vitamin K for the pig and does not appear to have any adverse effects, even when administered at levels higher than those normally used in pig food supplementation.

Synthesis of Tailored Segmented Polyurethanes Utilizing Continuous-Flow Reactors and Real-Time Process Monitoring

2021 ◽  
Author(s):  
Xabier Lopez de Pariza ◽  
Tim Erdmann ◽  
Pedro L. Arrechea ◽  
Leron Perez ◽  
Charles Dausse ◽  
...  
Keyword(s):  
Real Time ◽  
Process Monitoring ◽  
Continuous Flow ◽  
Time Process ◽  
Flow Reactors ◽  
Segmented Polyurethanes ◽  
Continuous Flow Reactors

Functional Group Interconversion Reactions in Continuous Flow Reactors

2021 ◽  
Vol 25 ◽  
Author(s):  
Alexander Leslie ◽  
Angel Maria Joseph ◽  
Marcus Baumann
Keyword(s):  
Continuous Flow ◽  
Functional Group ◽  
Modern Synthesis ◽  
Flow Reactors ◽  
Flow Synthesis ◽  
Specific Reaction ◽  
Solid Foundation ◽  
Continuous Flow Reactors ◽  
Flow Techniques

: An overview of the current uptake of continuous flow techniques for various functional group interconversion reactions is presented. Besides highlighting a variety of prominent examples and their main features, this review provides insights into specific reaction classes, such as oxidations, reductions, rearrangements as well as different C-H functionalization processes. While this review can only include key examples from the last decade, the reader will find a solid foundation of important transformations along with further references to inform and appreciate the opportunities arising from modern synthesis technologies such as flow synthesis.

Visible light-induced iniferter polymerization of methacrylates enhanced by continuous flow

2017 ◽  
Vol 8 (42) ◽  
pp. 6496-6505 ◽  
Author(s):  
Maarten Rubens ◽  
Phanumat Latsrisaeng ◽  
Tanja Junkers
Keyword(s):  
Block Copolymers ◽  
Visible Light ◽  
Continuous Flow ◽  
Flow Reactors ◽  
Continuous Flow Reactors

Visible-light induced photoiniferter polymerization in continuous flow reactors is very efficient in yielding low dispersity methacrylate block copolymers.

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