Biocatalytic microgels (μ-Gelzymes): synthesis, concepts, and emerging applications

18/11/2020
  Elisabeth Gau and Maximilian Noeth Copyright: © BIO VI

Maximilian Nöth, Elisabeth Gau, Falco Jung, Mehdi D. Davari, Islam El-Awaad,* Andrij Pich,* and Ulrich Schwaneberg* Green Chemistry, 2020, DOI 10.1039/D0GC03229H

These authors contributed equally to the work

Project: SFB 985

Funding: DFG: Collaborative Research Centre 985 “Functional Microgels and Microgel Systems; BMBF: Next Generation of Biotechnological Processes – Biotechnology 2020+

Subgroup: Biohybrid Systems and Computational Biology

 

Biocatalytic microgels are an attractive new type of catalyst with huge application potential for the field of green chemistry.

Enzymes are nature’s catalysts able to perform (bio)chemical reactions with impressive chemo-, regio-, and stereoselectivities and have great potential for sustainable processes from renewable resources. The adaptation of enzymes to the requirements of industrial processes is a prerequisite to harness their benefits in large-scale transformations for the synthesis of fine chemicals, food products, and pharmaceuticals. Immobilisation of wild-type or engineered enzymes using natural and synthetic carriers has been extensively employed to improve catalytic performance, ensure recovery and reuse, and thereby promote their use in industrial processes. Microgels as containers for protein immobilisation are advancing into a promising alternative as reflected by a growing body of literature that documents their use in sustainable catalytic processes. Microgels are porous, high molecular mass crosslinked submicron-sized colloidal polymer networks, which are swollen by the solvent in which they are dissolved (e.g., water). They can be designed to adjust their shape and volume upon external stimuli such as temperature, pH, ionic strength, and solvent nature. Microgels are ideal enzyme carriers due to their chemical and mechanical stability, tuneable architecture, biocompatibility, high water content, and their ability to achieve high enzyme loadings. In this review, we summarise the progress in the synthesis and applications of enzyme-loaded microgels (μ-Gelzymes). We start by exploring the different approaches used for enzyme immobilisation on or within microgels and give representative examples for the use of μ-Gelzymes in different applications. Subsequently, the potential of μ-Gelzymes in achieving sustainable catalysis is discussed from a green chemistry perspective. Finally, we draw future directions for further improvement of biocatalytic μ-Gelzymes as an emerging interdisciplinary research field of interactive soft matter.

  Overview of µ-Gelzymes categorised according to the methodologies for enzyme immobilisation Copyright: © Green Chemistry - Royal Society of Chemistry  

Figure 1 Overview of µ-Gelzymes categorised according to the methodologies for enzyme immobilisation. Enzymes can be immobilised covalently on pre-synthesised microgels or immobilised during microgels synthesis. Alternatively, the stimuli-responsiveness of microgels (switchable enzyme carriers) can be utilised for enzyme immobilisation. Adapted from Nöth et al. (2020) with permission of the Royal Society of Chemistry.