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Biotransformations in microstructured reactors: more than flowing with the stream?

2011; Elsevier BV; Volume: 29; Issue: 7 Linguagem: Inglês

10.1016/j.tibtech.2011.03.005

0167-9430

Juan M. Bolívar, Johanna Wiesbauer, Bernd Nidetzky,

Viral Infectious Diseases and Gene Expression in Insects

The state of the art in the application of microstructured flow reactors for biocatalytic process research is reviewed. A microstructured reactor that is fully automated and analytically equipped presents a powerful screening tool with which to perform biocatalyst selection and optimization of process conditions at intermediary stages of process development. Enhanced mass transfer provided by the microstructured reactor can be exploited for process intensification, particularly during multiphase biocatalytic processing where mass transfer across phase boundaries is often limiting. Reversible immobilization of enzymes in microchannels remains a challenge for flexible realization of biotransformations in microstructured reactors. Compartmentalization in microstructured reactors could be useful in performing multistep chemoenzymatic conversions. The state of the art in the application of microstructured flow reactors for biocatalytic process research is reviewed. A microstructured reactor that is fully automated and analytically equipped presents a powerful screening tool with which to perform biocatalyst selection and optimization of process conditions at intermediary stages of process development. Enhanced mass transfer provided by the microstructured reactor can be exploited for process intensification, particularly during multiphase biocatalytic processing where mass transfer across phase boundaries is often limiting. Reversible immobilization of enzymes in microchannels remains a challenge for flexible realization of biotransformations in microstructured reactors. Compartmentalization in microstructured reactors could be useful in performing multistep chemoenzymatic conversions. a functional microchannel structure, typically on a plate, fabricated by microtechnology and precision engineering. A fully equipped and interfaced reactor containing a microstructured element for chemical processing under flow conditions. Instrumentation refers to fluid handling, analytics and control. A miniaturized ‘reactor’ using a flat plate containing multiple (often 96) wells of 10–100 μl volume that serve as parallelized reaction vessels. The plates are typically agitated by shaking. Magnetic stirring is used less often. The system can be applied for batch and fed-batch experiments. a unibody porous structure composed of interconnected repeating cells or channels. enhancement of production capacity by parallelization. dramatic reduction of reactor size while achieving given production objective and/or improvement of key chemical process features such as yield or selectivity. a measurement performed directly inside the reactor, distinguished from methods that involve sampling via a bypass and return the sample into the stream (on-line) or discard it after measurement (at-line). Off-line measurement means that a sample is taken and analyzed later. FIA is an automated method of (high-throughput) analysis that involves injection of the sample into the continuous flow of a single phase. CSFA is a similar method that uses segmented flow of air-aqueous or organic-aqueous phases. The fluidic pattern applied in FIA and CSFA, where tubings with internal diameter of 0.5–2 mm are used, partially overlaps with that occurring in modern microstructured devices. Enzymes were immobilized in reaction tubings with the aim of converting the analyte into a detectable product. One could consider FIA and CSFA as early applications of immobilized enzymes under conditions of microstructured flow. a flow regime in L/L and G/L flows that occurs under conditions of dispersed-phase contacting and is therefore categorized as a segmented type of flow. Slugs (or plugs) of the dispersed phase span the entire diameter of the channel. They migrate through the channel while being separated by pockets of the continuous phase. a monolithic glass/polymer composite material shaped in the form of Raschig rings are assembled on a central rod to give a reactor of tubular shape. Fluid flow is through the monolithic material. Raschig rings are pieces of tube that are approximately equal in length and diameter.