Use of celite-immobilised chloroperoxidase in predominantly organic media

It is possible to use the chloroperoxidase from Caldariomyces fumago to cat alyse the oxidation of benzyl alcohol to benzaldehyde in predominantly orga nic media, even at water activities below 1.0, if the oxidant is tert-butyl hydroperoxide. The enzyme activity increased with increasing water activit y and no enzyme activity was observed at water activities below 0.6. Hydrop hobic solvents such as cyclohexane showed the highest initial activities. I I 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 benzy l alcohol in cyclohexane was estimated to be 13 mM while the initial reacti on rate increased almost linearly up to 250 mM tert-butyl hydroperoxide.