Activity and substrate specificity of the fatty alcohol oxidase of Candida tropicalis in organic solvents

Abstract

The alkane-induced, membrane-bound fatty alcohol oxidase of Candida tropicalis was functional with decanol as a model substrate in C8 to C12 alkanes and in cyclohexane. Optimal activity was with octane. Although some reaction took place without added water, 5–10% water gave optimal activity. A continuous spectrophotometric assay for following the enzyme activity in this system was developed. The enzyme, besides oxidizing primary long straight-chained alcohols, also oxidized long-chain diols, ω-hydroxy fatty acids, unsaturated fatty alcohols and branched-chained unsaturated fatty alcohols, although at diminished rates. Secondary alcohols or arylalkan-1-ols were not attacked. The Km for dodecanol was some 5000-fold higher than the Km for the same substrate when the reaction was carried out in water.