Engineered Bacillus pumilus laccase-like multi-copper oxidase for enhanced oxidation of the lignin model compound guaiacol

Laccases and laccase-like multi-copper oxidases (LMCOs) are versatile and robust biocatalysts applied in a variety of oxidative processes, and various studies have attempted to improve their catalytic activity. Here we report the engineering of a bacterial LMCO for enhanced oxidation of the lignin-related compound guaiacol by a combination of structure-guided mutagenesis and DNA shuffling. Mutant L9 showed a 1.39mM K-m for guaiacol and a 2.5-fold increase in turnover rate (k(cat)/K-m = 2.85.10(4) M(-1)s(-1)).