Construction of a xylose metabolic pathway in Trichosporonoides oedocephalis ATCC 16958 for the production of erythritol and xylitol.

Purpose: Erythritol is a valuable compound as sweetener and chemical material however cannot be fermented from the abundant substrate xylose.

Methods: The strain Trichosporonoides oedocephalis ATCC 16958 was employed to produce polyols including xylitol and erythritol by metabolic engineering approaches.

Results: The introduction of a substrate-specific ribose-5-phosphate isomerase endowed T. oedocephalis with xylose-assimilation activity to produce xylitol, and eliminated glycerol production simultaneously. A more value-added product, erythritol was produced by further introducing a homologous xylulose kinase. The carbon flux was redirected from xylitol to erythritol by adding high osmotic pressure. The production of erythritol was improved to 46.5 g/L in flasks by fermentation adjustment, and the process was scaled up in a 5-L fermentor, with a 40 g/L erythritol production after 120 h, and a time-space yield of 0.56 g/L/h.

Conclusion: This study demonstrated the potential of T. oedocephalis in the synthesis of multiple useful products from xylose.