Abstract: A rapid method of partially purifying carnitine acetyltransferase (CAT) from Candida tropicalis and determination of its enzyme activity was established.The characteristics of CAT-disruption recombinant of Candida tropicalis were also studied.It was confirmed that the specific activity of CAT of this recombinant was approximately half of that of its corresponding wild type. Therefore, the β-oxidation pathway of dicarboxylic acid was effectively suppressed. Correspondingly, the dicarboxylic acid productivity of this recombinant was increased by 11% and its alkane conversion rate was also increased by 12% in average.