Baeyer-Villiger monooxygenases: From protein engineering to biocatalytic applications

Biocatalytic processes are well established for the synthesis of high-value fine chemicals, especially for chiral pharmaceutical intermediates, by using natural or engineered enzymes. In contrast, examples for the enzymatic synthesis of bulk chemicals are still rare. Especially for the synthesis of polymer precursors such as ɛ-caprolactone, that is still produced under harsh conditions by using peracetic acid, Baeyer-Villiger monooxygenases (BVMOs) represent promising alternative catalysts that can perform the reaction under mild conditions. However, industrial production of this bulk chemical using a biocatalyst such as a BVMO has not been achieved yet due to a number of reasons. In this book chapter, we are emphasizing the versatility of BVMOs and their catalyzed reactions, and address several examples where protein engineering was applied in order to overcome several limitations associated to the use of BVMOs. Finally, we highlight several examples of BVMO applications, either in single enzyme transformations, or BVMOs involved in cascade reactions. By mainly focusing on recent developments and achievements in the field, we outline different concepts that were developed in order to pave the way for an industrial application of BVMOs.