Improving Erythritol Production of Aureobasidium pullulans from Xylose by Mutagenesis and Medium Optimization

The biotransformation of xylose, the second most abundant sugar, has been a hot topic in recent years. In this work, Aureobasidium pullulans CGMCC3.0837 was subjected to UV mutagenesis to improve its erythritol production from xylose. The erythritol production of the obtained mutant ER35 was 50.92 % (17.28 g/L) higher than that of the parent strain. Response surface methodology was applied to optimize the medium composition. Yeast extract, KH₂PO₄, and citric acid were the key factors influencing erythritol synthesis, and the optimal concentrations were 17.82, 0.76, and 6.60 g/L, respectively. Under the optimized conditions, 31.75 and 31.42 g/L erythritol were obtained in shake flasks and in a 5-L fermentor, respectively. ER35 also showed a good consuming ability on xylose mother liquor with a final erythritol production of 26.35 g/L. This report provided insights into the potential of A. pullulans for the production of erythritol using xylose as a carbon source.