Large scale production of vanillin using an eugenol oxidase from Nocardioides sp. YR527

Bacterial eugenol oxidases (EUGOs) entered recently the scientific spotlight as these versatile biocatalysts were reported to transform lignin degradation products into valuable platform chemicals. Here we describe the second member of the enzyme family, EUGO from Nocardioides sp. YR527 (NspEUGO) and investigated its biocatalytic potential in direct comparison with EUGO from Rhodococcus jostii RHA1. NspEUGO was found to be most active on vanillyl alcohol derivatives (up to 5.6 & PLUSMN; 0.3 s(-1)) while for eugenol the highest affinity was observed (K-M: 33.1 & PLUSMN; 4.1 & mu;M). For the catalyzed reactions, a high ambiguity was observed in dependency of the pH: The highest k(cat) of 16.0 & PLUSMN; 0.3 s(-1) was found at pH 9.5 while the best long-term performance was detected at pH 6.0 (similar to 300,000 TTN). To stabilize the enzyme, immobilization on a total of 14 carrier materials was conducted and the performance was investigated in two reactor types for large scale application. This resulted in the successful production of vanillin at 1 g L-1 h(-1) in a packed bed reactor.

Automated summary

Bacterial eugenol oxidases (EUGOs) have been identified as versatile biocatalysts that can transform lignin degradation products into valuable platform chemicals. In this study, we characterized a new member of the EUGO enzyme family, NspEUGO, and compared its biocatalytic potential with EUGO from Rhodococcus jostii RHA1. NspEUGO showed highest activity on vanillyl alcohol derivatives and exhibited the strongest affinity for eugenol. Immobilization of the enzyme on 14 carrier materials allowed for successful production of vanillin in a packed bed reactor.