New enzymes in the fight against CO2: revolution in biocatalysis!

New enzymes in the fight against CO2: revolution in biocatalysis!

On April 30, 2025, the Ruhr University Bochum presented a new specialist book entitled “Biocatalysis”, edited by Prof. Dr. Dirk Tischler, a respected biotechnologist at the university. This comprehensive work includes 24 chapters, seven of which were written by researchers from the Ruhr University and one from Dortmund. It covers the broad subject matter from biology to chemistry to medicine and biotechnology, in particular the application of biocatalysts, especially enzymes, in industrial processes.

The book addresses the evaluation and identification of new enzymes and their application in cell-free and cell-based formats. A key concern is enzyme immobilization as well as current topics such as CO2 elimination and CO2-based techniques. These issues are of great importance for both the production of fine chemicals and the degradation of PET. news.rub.de also reports that the book is published in the prestigious Methods in Enzymology series by Academic Press and is available under ISBN 978-0443317880, including a full-text download.

The relevance of new catalytic systems

This reassessment of biocatalysts is particularly important given current environmental issues. The need for new concepts for using carbon dioxide for a circular carbon economy is growing to minimize ecological footprints. In this context, photocatalysis, electrocatalysis, thermal catalysis and biocatalysis are important tools that prefer to operate in aqueous solutions. pubmed.ncbi.nlm.nih.gov points out that efficient systems operating in water are rare.

A promising approach is the identification of specific enzymes for CO2 reduction. This is based on structural analysis of potential CO2 binding sites and subsequent mutations to optimize the catalysts. In particular, the phenolic acid decarboxylase of *Bacillus subtilis* (BsPAD) was identified as a key component that contributes significantly to the aqueous photocatalytic CO2 reduction to carbon monoxide.

• Mit modifizierten Varianten von BsPAD wurden Turnover-Zahlen (TONs) von bis zu 978 erzielt.
• Die Selektivität für Kohlenmonoxid über die Bildung von Wasserstoff betrug beeindruckende 93 %.
• Mutationen im aktiven Bereich von BsPAD führten zu weiteren Verbesserungen der Leistungsfähigkeit.
• Der Elektronentransfer erwies sich als geschwindigkeitsbestimmend und erfolgt über mehrstufiges Tunneln.

The approach was further verified by testing eight other enzymes that also showed the desired activity. This suggests that a large number of proteins are able to play a key role in photocatalytic CO2 reduction.

Overall, the newly published book is not only a valuable contribution to science, but also reflects a crucial step towards more sustainable and environmentally friendly biotechnological practice.