Recently Developed Evolved Enzymes to Produce Renewable Isobutene

A new research study published on September 7 details an innovation in developing advanced enzymes to sustain a renewable process to produce one of the vital products of the chemical industry (isobutene), used everywhere from beauty products to fuel.

The freshly published discoveries are the outcome of collective work between Global Bioenergies and the team of Dr. David Leys at The University of Manchester. The research has been released in the journal Nature Communications. This paper explains the evolution and mechanism of isobutene developing enzymes significantly superior to previously used catalysts. Isobutene is a high-value gaseous hydrocarbon and also a significant building block of the petrochemicals industry: approximately 15 million tons are produced annually to produce cosmetic ingredients, rubber, and fuel.

For the first time, an extensive enzyme family member that depends on an unusual vitamin B2 by-product has been repurposed to produce isobutene. This was possible due to the thorough work executed on both sides of the Channel, with laboratory-guided evolution carried out at Global Bioenergies, and meticulous structure analysis of the evolved enzymes at The University of Manchester.

David Leys, team leader at the Manchester Institute of Biotechnology of The University of Manchester, says: “Our partnership with Global Bioenergies on the matter of isobutene production combines uniquely quantitative molecular bioscience and industrial, high-throughput approaches. It is pleasing to see how a fundamental understanding of these enzymes acquired with European Research Council funding supports the industrial application. The evolved enzymes stand for many orders of magnitude improvement in the efficiency of isobutene bioproduction, contributing directly to an economically practical and renewable process, and therefore a more lasting future.”

Marc Delcourt, co-founder, and CEO of Global Bioenergies adds: “Nature Communications is among the elite peer-reviewed scientific journals. We are delighted to see the work we conducted together with the group of Dr. David Leys reaches such a distinctive scientific recognition. The evolved enzymes, on which GBE holds special intellectual property rights for the isobutene manufacturing, will have an important part in the ecological change our world is now participating in.”

Global Bioenergies concocted an altered path for manufacturing isobutene from glucose as an alternative to fossil fuel-derived isobutene. The essential last step yielding the wanted product uses a decarboxylase enzyme. This specific enzyme has evolved from naturally occurring microbial decarboxylases that rely on an elaborately modified Vitamin B2 (prenylated flavin or prFMN) for the activity.

The Manchester team has led the studies on these prFMN-dependent catalysts and defined structural and biochemical properties of isobutene yielding enzymes evolved by Global Bioenergies. The enterprise sifted an enzyme library for intrinsic isobutene production activity and used directed evolution to produce variants with an 80-fold rise in the activity. Structure determination of the evolved catalysts shows that modifications in the enzyme pocket are responsible for enhanced production, while solution and computational research studies imply that isobutene release is currently the limiting factor.

Global Bioenergies has developed a novel conversion process for renewable energies right into isobutene, one of the leading petrochemical building blocks that can be converted into components for cosmetics, gasoline, kerosene, LPG, and plastics.

Originally published by the University of Manchester. Read the original article.

Reference: Annica Saaret et al, Directed evolution of prenylated FMN-dependent Fdc supports efficient in vivo isobutene production, Nature Communications (2021). DOI: 10.1038/s41467-021-25598-0