Previous studies indicated that lignin peroxidase (LiP) hosted at CTAB/n-alcohol/isooctane/water reversed micelle did not show any catalytic activity, but in normal micellar solution of CTAB, LiP could express its catalytic activity. To reveal the role of normal alcohol, the effects of the alcohol with different carbon chain length on the catalytic activity of LiP were investigated. Because the content of the alcohol in the CTAB reversed micellar medium was high and the normal alcohols with the number of carbon atoms higher than 4 were slightly soluble in water, three media in which LiP could express its catalytic activity, i.e., a CTAB normal micellar medium, an AOT reversed micellar medium, and a Brij 30 reversed micellar medium, were used to study the effect of normal alcohols on the catalytic activity of LiP. Results indicated that as long as the concentration of the alcohol exceeded 500 mmol•L^－1 (≥1200 mmol•L^－1 for butanol), LiP lost its activity completely in the three media above regardless of the structure, the electrical property and the size of the surfactant aggregates. Consequently it was deduced that the phenomenon that LiP hosted at CTAB reversed micelles could not express its activity was mainly due to the alcohol co-surfactant.

Key words: lignin peroxidase, normal alcohol, reversed micelle, catalytic activity