High-level productivity of α,ω-dodecanedioic acid with a newly isolated Candida viswanathii strain.

α,ω-Dicarboxylic acids (DC) are versatile chemical intermediates with different chain lengths, which are well-known as polymer building block. In this work, a new strain with high productivity of DC was isolated from oil-contaminated soil. Based on the morphology and phylogenetic analyses of the internal transcribed spacer sequences, it was characterized as Candida viswanathii. It was found that the contribution of carbon flux to the cell growth and DC production from n-dodecane could be regulated by the sucrose and yeast extract concentrations in the medium, and besides the broth pH, a suitable proportioning of sucrose and yeast extract was the key to achieve the optimal transition from cell growth phase to DC production phase. By optimizing culture conditions in a 7.5-L bioreactor, a higher DC productivity of 1.59 g·L-1 h-1 with a corresponding concentration of 181.6 g/L was obtained. After the purification of DC from the culture, the results from gas chromatography-mass spectrometry, infrared spectroscopy and 1H-NMR showed that α,ω-dodecanedioic acid (DC12) was the major product of C. viswanathii ipe-1 using pure n-dodecane as substrate. For the first time, we reported that a high productivity of DC12 could be produced by C. viswanathii.