Directed evolution of the aryl-alcohol oxidase: Beyond the lab bench

Aryl-alcohol oxidase (AAO) is a fungal GMC flavoprotein secreted by white-rot fungi that supplies H(2)O(2) to the ligninolytic consortium. This enzyme can oxidize a wide array of aromatic alcohols in a highly enantioselective manner, an important trait in organic synthesis. The best strategy to adapt AAO to industrial needs is to engineer its properties by directed evolution, aided by computational analysis. The aim of this review is to describe the strategies and challenges we faced when undertaking laboratory evolution of AAO. After a comprehensive introduction into the structure of AAO, its function and potential applications, the different directed evolution enterprises designed to express the enzyme in an active and soluble form in yeast are described, as well as those to unlock new activities involving the oxidation of secondary aromatic alcohols and the synthesis of furandicarboxylic acids.