In-depth analysis of erythrose reductase homologs in Yarrowia lipolytica

Abstract

The unconventional yeast Yarrowia lipolytica produces erythritol as an osmoprotectant to adapt to osmotic stress. In this study, the array of putative erythrose reductases, responsible for the conversion of d-erythrose to erythritol, was analyzed. Single knockout and multiple knockout strains were tested for their ability to produce polyols in osmotic stress conditions. Lack of six of the reductase genes does not affect erythritol significantly, as the production of this polyol is comparable to the control strain. Deletion of eight of the homologous erythrose reductase genes resulted in a 91% decrease in erythritol synthesis, a 53% increase in mannitol synthesis, and an almost 8-fold increase in arabitol synthesis as compared to the control strain. Additionally, the utilization of glycerol was impaired in the media with induced higher osmotic pressure. The results of this research may shed new light on the production of arabitol and mannitol from glycerol by Y. lipolytica and help to develop strategies for further modification in polyol pathways in these microorganisms.

Transcriptome analysis reveals multiple targets of erythritol-related transcription factor EUF1 in unconventional yeast Yarrowia Lipolytica

“…The importance of erythritol for survival of this yeast might be indicated by the presence of multiple homologs of erythrose reductase. Deletion of eight of them results in 91% decrease in erythritol synthesis, but so far, it has not been possible to obtain a strain completely unable to produce erythritol [ 6 ].…”

“…Impaired erythritol production, caused by the damage to HOG or the aforementioned deletions of numerous erythrose reductases, resulted in significantly increased osmo-sensitivity. However, such strains were able to grow under osmotic stress conditions if erythritol was supplemented in the media [ 6 , 8 ].…”