A mutant, Candida tropicalis P-12-242, which can produce undecane 1, 11-Dicarboxylic acid(DC13) from N-Tridecane(nC13), was obtained by treating the parent stain UH-2-48 with sodium nitrite. On 2500L fermenter testing, under the optimum condition where the fermentation medium contained total 26% nC13, pH of the course of fermentation was maintained range 7.5-8.0, at 28 degrees C-30 degrees C, the highest level of DC13 production was obtained after 6 d, and the average amount of DC13 accumulated was 182.6 g/L in broth. After received residual nC13, The average consumption rate of DC13 from nC13 was 87.8%. The purity of the product DC13, which was analyzed by gas chromatography was about 96.8%.
