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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