Debaryomyces hansenii fermentation for arabitol production

•Produced arabitol as the only polyol product from glycerol.•Optimized process, including control of pH and dissolved oxygen concentration.•Improved medium composition critical for growth and productivity.•Achieved 3-fold increase in volumetric productivity of arabitol.•Obtained 55% yield and 0.33 g/L-h volumetric productivity of arabitol from glycerol.

The fermentation process for arabitol production from glycerol was developed using a Debaryomyces hansenii strain recently selected from a broad screening. The high-producing strain produced arabitol as the only detectable polyol from glycerol. In this work, the pH, dissolved oxygen concentration (DO), inoculum size and magnesium concentration, and the nitrogen-to-phosphorus (N/P) ratio were systematically evaluated for effects on cell growth rate and arabitol productivity. Among those evaluated, the medium with N/P = 9, DO of 5% air saturation and pH 3.5 supported the highest arabitol production. Under these optimal conditions, arabitol production of 40 g/L was achieved in 5 days compared to earlier studies with 15 g/L arabitol in 5 days. Volumetric productivity and specific productivity were successfully improved from 0.13 to 0.33 g/L-h and 0.007 to 0.02 g/g-h respectively with arabitol yield of 55% from glycerol.

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