Use of celite-immobilised chloroperoxidase in predominantly organic media

It is possible to use the chloroperoxidase from Caldariomyces fumago to catalyse the oxidation of benzyl alcohol to benzaldehyde in predominantly organic media, even at water activities below 1.0, if the oxidant is tert-butyl hydroperoxide. The enzyme activity increased with increasing water activity and no enzyme activity was observed at water activities below 0.6. Hydrophobic solvents such as cyclohexane showed the highest initial activities. It was beneficial in terms of obtainable yield to use high concentrations of the peroxide due to the kinetics of the system. The apparent K(m) for benzyl alcohol in cyclohexane was estimated to be 13 mM while the initial reaction rate increased almost linearly up to 250 mM tert-butyl hydroperoxide.