Let the Biocatalyst Flow

Abstract

Industrial biocatalysis has been identified as one of the key enabling technologies that, together with the transition to continuous processing, offers prospects for the development of cost-efficient manufacturing with high-quality products and low waste generation. This feature article highlights the role of miniaturized flow reactors with free enzymes and cells in the success of this endeavor with recent examples of their use in single or multiphase reactions. Microfluidics-based droplets enable ultrahigh-throughput screening and rapid biocatalytic process development. The use of unique microreactor configurations ensures highly efficient contacting of multiphase systems, resulting in process intensification and avoiding problems encountered in conventional batch processing. Further integration of downstream units offers the possibility of biocatalyst recycling, contributing to the cost-efficiency of the process. The use of environmentally friendly solvents supports effective reaction engineering, and thus paves the way for these highly selective catalysts to drive sustainable production.

Two-Phase Biocatalysis in Microfluidic Droplets

“…Flow chemistry has been performed in organic chemistry laboratories in academia and industry for the development, optimization, and intensification of chemical processes for several decades [ 23 ]. More recently, the first biocatalytic reactions performed in microfluidics were reported [ 24 , 25 ]; however, flow biocatalysis today remains in its infancy compared to flow chemistry.…”

“…In the biocatalysis field, this has led to the development of microfluidics-based screening methods for activity-based screening of metagenomic libraries [ 30 , 31 ] or mutant libraries derived from enzyme evolution campaigns [ 32 , 33 ]. Additionally, enzyme characterization and process parameter estimation and optimization are also facilitated by the use of microfluidic devices (often microfluidic droplets) due to ultra-high throughput and low reagent consumption [ 23 , 34 , 35 , 36 ]. In addition to high-throughput screening and characterization possibilities, miniaturization provides a tool that allows researchers to gain an understanding of fundamental process principles and reaction characteristics.…”

“…These can be divided into three main categories: (1) microfluidic droplets for ultrahigh-throughput library screening, (2) microfluidic droplets for enzyme characterization and parameter estimation, and (3) intensification of two-phase biocatalytic reactions using microfluidic droplets or droplet-like fluid flows. The first two categories have already been reviewed comprehensively in recent literature and will not be further discussed in this perspective [ 23 , 30 , 33 , 34 ]. Herein, we focus on synthetically useful biocatalytic reactions employing two liquid phases, in an effort to highlight the benefits and limitations associated with droplet microfluidics when used to perform these reactions.…”

Analytical Modeling of Thermodynamic and Transport Anomalies of Water

“…The hydrogen bonding part is the sum of interactions between all pairs of the arms of different molecules (3) and is described by Gaussian function in distance and both angles (4) Here, e HB = -1 is a HB energy parameter and r HB = i is a characteristic length of HB, u u ij is the unit vector along r u ij and i u k is the unit vector of the k th arm of the particle I, and q i is the unit vector of the i th arm of the particle j. q i , q j are the orientations of the particle with respect to x axes. G(x) is the unnormalized Gaussian function (5) The strongest hydrogen bond occurs when an arm of one particle is co-linear with the arm of another particle and the two arms point in opposing directions. The LJ well-depth e LJ is 0.1 times the HB interaction energy |e HB | and the Lennard-Jones contact parameter s LJ is 0.7 r HB .…”

“…Water controls the planets geochemical cycles; is a dominant driver of biomolecules, drug interactions, and biological actions; and central to green chemistry and many industrial processes. 5,6 Water is essential for our bodies. Every major system in our body depends on water to function since approximately two thirds of your body is water.…”