Abstract:The effects of three kinds of surfactants (Triton X-100, di-RL, CTAB) on hexadecane degradation by Candida tropicalis CICC 1463 were studied. Triton X-100 with low concentrations had little effects on cell growth and hexadecane degradation, but had inhibitive effects at high concentrations. After 96 hours, average residual rate of hexadecane was 20.5%, 20.2%, 22.0%, 54.4%, 71.2% and 68.8% for the Triton X-100 concentration of 0, 0.1, 0.3, 0.5, 1.0 and 3.0CMC, respectively. di-RL increasingly enhanced cell growth and hexadecane degradation with concentration increasing, and average residual rate of hexadecane decreased to 17.4%, 16.6%, 9.9%, 8.8% and 7.8% for the concentration 0.1, 0.3, 0.5, 1.0 and 3.0CMC of di-RL after 96 hours. di-RL was also degraded in the fermentation process, and the degradation rate increased with increasing di-RL concentration. CTAB completely inhibited cell growth and hexadecane degradation, indicating its toxicity to Candida tropicalis CICC 1463.