A Role of a Newly Identified Isomerase From Yarrowia lipolytica in Erythritol Catabolism

Abstract

Erythritol is a natural sweetener produced by microorganisms as an osmoprotectant. It belongs to the group of polyols and it can be utilized by the oleaginous yeast <i>Yarrowia lipolytica</i>. Despite the recent identification of the transcription factor of erythritol utilization (<i>EUF1</i>), the metabolic pathway of erythritol catabolism remains unknown. In this study we identified a new gene, <i>YALI0F01628g</i>, involved in erythritol assimilation. <i>In silico</i> analysis showed that <i>YALI0F01628g</i> is a putative isomerase and it is localized in the same region as <i>EUF1</i>. qRT-PCR analysis of <i>Y. lipolytica</i> showed a significant increase in <i>YALI0F01628</i>g expression during growth on erythritol and after overexpression of <i>EUF1</i>. Moreover, the deletion strain <i>ΔF01628</i> showed significantly impaired erythritol assimilation, whereas synthesis of erythritol remained unchanged. The results showed that <i>YALI0F1628g</i> is involved in erythritol assimilation; thus we named the gene <i>EYI1</i>. Moreover, we suggest the metabolic pathway of erythritol assimilation in yeast <i>Y. lipolytica</i>.