Material Research: Biocatalytic Foams with Tremendous Durability and Activity
Industrial biocatalysis with enzymes is seen as a “game changer” in the development of a sustainable chemical industry. With the help of enzymes, an impressive range of complex molecules, such as pharmaceutical active ingredients, can be synthesized under environmentally friendly conditions. Researchers at the Karlsruhe Institute of Technology (KIT) from the Helmholtz Research Field Information have now developed a new class of materials by producing enzymes as foams that possess an enormous durability and activity. The researchers report on their results in the scientific journal Advanced Materials. The novel manufacturing process of the enzyme foams has already been filed for patenting. (Source: Karlsruhe Institute of Technology – Press Releases)
Please note: The text has been translated using a machine translation tool and may contain inaccuracies.
In order to further develop the field of industrial biocatalysis, which is primarily used in the production of pharmaceuticals and specialty chemicals, researchers are intensively working on new process technologies. In biocatalysis, enzymes accelerate reactions instead of chemical catalysts, saving raw materials and energy. The goal is now to provide enzyme biocatalysts continuously and in large quantities under as gentle conditions as possible. To make efficient substance conversions possible, the enzymes are immobilized in microstructured flow reactors. They are spatially fixed and bound to a reaction-inert material, thus being restrictedly mobile, which leads to a higher concentration of enzymes and thus to higher productivity.
Foamed Microdroplets from Self-organizing Enzymes
Normally, enzymes change their structure when foaming and thus lose their biocatalytic activity. The new protein foams, however, have enormous durability and activity. Activity is a measure of the enzyme’s effectiveness in ensuring that starting materials react with each other as quickly as possible. For the production of the protein foams, two dehydrogenase enzymes are mixed, which carry matching linkage sites so that they can spontaneously form a stable protein network. “This mixture is then introduced into a microfluidic chip with a gas stream, so that microscopic bubbles of uniform size are formed in a controlled manner,” explains Professor Christof Niemeyer from the Institute for Biological Interfaces-1 the process. The foam thus produced with uniform bubble size is applied directly to plastic chips and dried, causing the proteins to polymerize and form a stable, hexagonal grid.
“These are monodisperse ‘full-enzyme foams’, that is, three-dimensional, porous networks made exclusively of biocatalytically active proteins,” Niemeyer characterizes the composition of the new materials. The stable hexagonal honeycomb structure of the foams has a mean pore diameter of 160 µm and a lamellar thickness of 8 µm and is formed from the freshly produced, approximately equally sized spherical bubbles within a few minutes.
Active and Stable Full-Enzyme Foams Efficiently Employed
To be able to efficiently use enzymes for substance transformations, they have to be immobilized in large quantities under as gentle conditions as possible in order to maintain their activity. So far, enzymes have been immobilized on polymers or carrier particles, but this requires valuable reactor space and can impair activity. “Compared to our previously developed ‘full-enzyme hydrogels’, the new foam-based materials create a significantly larger surface area where the desired reaction can take place,” Niemeyer describes the essential improvement. Contrary to theoretically expected results, the new foams surprisingly show a strikingly high durability, mechanical resistance, and catalytic activity of the enzymes, which has not been achieved before with the foaming of proteins.
The stability, researchers suspect, is due to the matching linkage sites with which the enzymes are equipped. They can self-assemble and thus form a highly crosslinked lattice during drying, giving the new material unique stability. “Surprisingly, the newly developed enzyme foams are significantly more stable after drying for four weeks than the same enzymes without foams,” Niemeyer explains the advantages, “this is of great interest for marketing, as it greatly simplifies stock production and shipping.”
The new biomaterials open up versatile paths for innovations in industrial biotechnology, materials science, and even food technology. The protein foams could be used in biotechnological processes to produce valuable compounds more efficiently and sustainably. The research team was able to show that the industrially valuable sugar Tagatose can be produced using the foams, which represents a promising alternative to refined sugar as a sweetener.
KIT/S. Fodi, 27.07.2023
The original press release can be found at:
Materialforschung: Biokatalytische Schäume mit enormer Haltbarkeit und Aktivität (only in german)
The original publication can be found at:
Julian S. Hertel, Patrick Bitterwolf, Sandra Kröll, Astrid Winterhalter, Annika J. Weber, Maximilian Grösche, Laurenz B. Walkowsky, Stefan Heißler, Matthias Schwotzer, Christof Wöll, Thomas van de Kamp, Marcus Zuber, Tilo Baumbach, Kersten S. Rabe, Christof M. Niemeyer: Biocatalytic Foams from Microdroplet-Formulated Self-Assembling Enzymes. Advanced Materials, 2023. DOI: 10.1002/adma.202303952
Localization in the Helmholtz Research Field Information:
Helmholtz Research Field Information, Program 3: Materials Systems Engineering, Topic 3: Adaptive and Bioinstructive Materials Systems
Contact:
Prof. Dr. Christof Niemeyer
Institute for Biological Interfaces (IBG)
Karlsruhe Institute of Technology (KIT)
Phone: +49 721 608-23000
E-Mail: niemeyer@kit.edu
Contact for this press release:
Dr. Sabine Fodi
Press Officer
Karlsruhe Institute of Technology (KIT)
Phone: +49 721 608-41154
E-Mail: sabine.fodi@kit.edu
