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

Abstract

Erythritol is a valuable compound as sweetener and chemical material however cannot be fermented from the abundant substrate xylose. The strain Trichosporonoides oedocephalis ATCC 16958 was employed to produce polyols including xylitol and erythritol by metabolic engineering approaches. 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 46.5g/L in flasks by fermentation adjustment, and the process was scaled up in a 5-L fermentor, with a 40g/L erythritol production after 120h, and a time-space yield of 0.56g/L/h. This study demonstrated the potential of T. oedocephalis in the synthesis of multiple useful products from xylose.