Engineering Yarrowia lipolytica to Produce l-Malic Acid from Glycerol

Area of Science:

• Biotechnology
• Metabolic Engineering
• Synthetic Biology

Background:

• Declining fossil resources drive demand for sustainable organic acid production.
• l-Malic acid is a vital four-carbon dicarboxylic acid with broad industrial applications.
• Previous microbial production of l-malic acid has not utilized *Yarrowia lipolytica*.

Purpose of the Study:

• To engineer *Yarrowia lipolytica* for efficient l-malic acid biosynthesis.
• To identify and overcome bottlenecks in the l-malic acid pathway.
• To achieve high-titer production of l-malic acid in a scalable system.

Main Methods:

• Overexpression of endogenous and heterologous genes in *Y. lipolytica*.
• Engineering the glyoxylate cycle and introducing a malate transporter.
• Medium optimization, adaptive laboratory evolution, and bioreactor scale-up.

Main Results:

• Engineered *Y. lipolytica* produced 27.0 g/L l-malic acid.
• Medium optimization increased production to 37.0 g/L.
• Adaptive evolution and scale-up yielded a final titer of 112.5 g/L.

Conclusions:

• This study demonstrates the first successful l-malic acid production in *Y. lipolytica*.
• The combination of metabolic engineering and adaptive evolution is effective for enhancing organic acid biosynthesis.
• This work enables large-scale sustainable production of l-malic acid and other organic acids.