Trimethyl-ε-caprolactone synthesis with a novel immobilized glucose dehydrogenase and an immobilized thermostable cyclohexanone monooxygenase

Abstract

An often associated drawback with Baeyer-Villiger monooxygenases, is its poor operational stability. Furthermore, these biocatalysts frequently suffer from substrate/product inhibition. In this work, a thermostable cyclohexanone monooxygenase (TmCHMO) was immobilized and used in the synthesis of trimethyl-ε-caprolactone (CHL). As a cofactor regeneration enzyme, a novel and highly active glucose dehydrogenase (GDH-01) was used immobilized for the first time. MANA-agarose was the carrier chosen since it presented an immobilization yield of 76.3 ± 0.7% and a retained activity of 62.6 ± 2.3%, the highest metrics among the supports tested. Both immobilized enzymes were studied either separately or together in six reaction cycles (30 mL; [substrate] =132.5 mM). A biocatalyst yield of 37.3 g g−1 of TmCHMO and 474.2 g g−1 of GDH-01 were obtained. These values represent a 3.6-fold and 1.9-fold increase respectively, compared with a model reaction where both enzymes were used in its soluble form.