Overexpression screen reveals transcription factors involved in lipid accumulation in Yarrowia lipolytica.

Yarrowia lipolytica is a non-conventional oleaginous yeast that displays high lipid titers and yields; its production capacity holds significant promise for industrial biolipid applications. While its lipid metabolism has been widely studied, little is known about its transcriptional regulatory network. Deciphering the role of transcriptional regulators is crucial for understanding lipid accumulation, a complex phenomenon. To identify the transcription factors involved in lipid metabolism, we developed a systematic overexpression approach for 148 putative transcription factors. Analyses of overexpressing transformants revealed that 38 had an impact on lipid accumulation under at least one of the growth conditions tested. For most of these factors, our results provide the first experimentally determined functional annotation. Our data suggest that the regulation network differs depending on the carbon source, which is critical information when carrying out industrial bioprocesses. These results will therefore help guide further rational metabolic engineering for improving biolipid production by Y. lipolytica. Moreover, this work has created the largest collection of Y. lipolytica overexpressing strains to date, which will be useful in phenotype screening.