Improving bioconversion of eugenol to coniferyl alcohol by in situ eliminating harmful H2O2

Coniferyl alcohol is a valuable chemical. However, the current approaches to obtain coniferyl alcohol are either unefficient or expensive. Penicillium simplicissimum vanillyl alcohol oxidase (PsVAO) can be used to produce coniferyl alcohol. However, PsVAO intrinsically produces harmful byproduct H2O2. Utilizing catalase to decompose H2O2 is a potential straightforward approach; however, catalase can also exhibit peroxidase activity to facilitate coniferyl alcohol over-oxidation. In this study, catalases exhibiting both high catalase activity and low peroxidase activity were found out, and introduced into the bioconversion systems. Our results showed that eliminating H2O2in situ released H2O2 inhibition of PsVAO, improved coniferyl alcohol production and eliminated coniferyl alcohol over-oxidation. Finally, coniferyl alcohol titer, molar yield, and productivity reached 22.9 g/L, 78.7%, and 0.5 g/(L × h) respectively. An efficient coniferyl alcohol production method was developed by overcoming the intrinsic disadvantages of PsVAO.