Comparative Transcriptome Analysis Reveals Key Genes Related to Erythritol Production in Yarrowia lipolytica and the Optimization of Culture Conditions

Erythritol has been widely used in the food industry, which predominantly synthesizes it via microbial fermentation, in which Yarrowia lipolytica serves as the preferred candidate chassis strain. However, the wild-type strain of Y. lipolytica exhibits several limitations, including suboptimal industrial performance and elevated levels of by-products, which pose significant challenges in biomanufacturing processes. It is significant to understand the synthesis mechanism of erythritol for improving the capacity of erythritol production by Y. lipolytica. In this study, a mutant exhibiting high erythritol production and stable genetic performance was obtained via a combination of UV and atmospheric and room-temperature plasma mutagenesis. Some key genes related to erythritol production were identified through comparative transcriptome analysis of the mutant strain, revealing significant changes in their expression levels. Individual overexpression of the genes encoding ribose-5-phosphate isomerase, glucose-6-phosphate-1-epimerase, adenylate kinase, and alcohol dehydrogenase in Y. lipolytica Po1g enhanced erythritol production, demonstrating the critical role of each gene in erythritol production. This finding elucidates the molecular mechanism underlying the improved erythritol yield in the mutant strain. The Y. lipolytica mutant C1 produced 194.47 g/L erythritol in a 10 L fermenter with a productivity of 1.68 g/L/h during batch fermentation, surpassing the wild-type strain and reducing the cultivation time by 21 h. It is significant to understand the mechanism of erythritol synthesis for improving erythritol production and its application in industrial-scale production.