Such source materials have thus far not been typically manufactured with the aid of biocatalysis, but rather from petroleum. In the opinion of leading scientists, the expansion of biotechnological processes to base, bulk and numerous specialty chemicals remains a largely unresolved challenge to this day.

If we can succeed in developing technically and economically feasible solutions in this area, we would be able to efficiently combine biotechnological and petrochemical processes in the chemical industry in the form of integrated production for greater added value.

—Dr. Thomas Haas, head of the Science & Technology unit at Creavis, Evonik’s strategic innovation unit

The Evonik researchers and the scientists working at Graz University under Professor Kurt Faber used naturally occurring short-chain alkanoic acid—saturated fatty acids produced by anaerobic bacteria—as the source material for 1-alkenes.

An established enzyme system—OleT P450 monooxygenase—produced the desired 1-alkenes from the short-chained fatty acids. This enzyme system catalyzes the corresponding chemical reaction—oxidative decarboxylation—efficiently and substrate-specifically to produce propene or 1-butene selectively and quantitatively.

However, the reaction also needs an oxidizing agent. While hydrogen peroxide had been used up to now, it not only results in unwanted secondary reactions but it can also damage the enzyme system. The Evonik/Graz team found that a cascade of two other enzyme systems can ensure that the electrons required for the re-dox process are no longer absorbed by H₂O₂ but by oxygen in the air.

It took the team a year to find an enzyme system for the optimal catalysis of converting the saturated fatty acids to 1-alkenes. The researchers are now working to transfer the enzyme combination to living cells.