Background: Succinic acid (SA) is a crucial metabolic intermediate and platform chemical. Development of biobased processes to achieve sustainable SA production has attracted more and more attention in biotechnology industry. Yarrowia lipolytica has a strong tricarboxylic acid cycle and tolerates low pH conditions, thus making it a potential platform for SA production. However, its SA titers in glucose media remain low.
Results: In this study, we screened mitochondrial carriers and C4-dicarboxylic acid transporters to enhance SA secretion in Y. lipolytica. PGC62-SYF-Mae strain with efficient growth and SA production was constructed by optimizing SA biosynthetic pathways and expressing the transporter SpMae1. In fed-batch fermentation, this strain produced 101.4 g/L SA with a productivity of 0.70 g/L/h and a yield of 0.37 g/g glucose, which is the highest SA titer achieved using yeast, with glucose as the sole carbon resource.
Conclusion: Our results indicated that transporter engineering is a powerful strategy to achieve the efficient secretion of SA in Y. lipolytica, which will promote the industrial production of bio-based SA.
Keywords: Glucose fermentation; Succinic acid; Transporter engineering; Yarrowia lipolytica.