Plasma‐driven biocatalysis: In situ hydrogen peroxide production with an atmospheric pressure plasma jet increases the performance of OleTJE when compared to adding the same molar amount of hydrogen peroxide in bolus

Enzymes like fatty acid peroxygenase OleTJE are desirable enzymes for the industry. While they require inexpensive hydrogen peroxide for activity, the same hydrogen peroxide also causes overoxidation of their reactive heme center. Here, we generate hydrogen peroxide slowly in situ using the Cooperation in Science and Technology (COST)‐Jet, an atmospheric pressure plasma jet, to avoid overoxidizing OleTJE. The COST‐Jet was operated in helium with a water admixture to provide hydrogen peroxide for OleTJE activity. This helium/water admixture produced the highest enzyme turnover numbers after 2 min of treatment. These turnover numbers were even superior to using an equimolar amount of hydrogen peroxide to treat the enzymes exogenously, showing that this plasma source can provide a reliable amount of reaction mediator to support OleTJE activity. Hydrogen peroxide is generated in situ for plasma‐driven biocatalysis. The fatty acid peroxygenase OleTJE is used to convert saturated fatty acids into more desirable unsaturated terminal alkenes. Turnover numbers after 2 min plasma treatment were superior to using an equimolar amount of hydrogen peroxide to treat the enzymes exogenously, showing that this plasma source can provide a reliable amount of reaction mediator to support OleTJE activity.