Model-Driven Engineering of Yarrowia lipolytica for Improved Microbial Oil Production

Area of Science:

• Biotechnology
• Synthetic Biology
• Microbial Engineering

Background:

• Palm oil production causes environmental and social issues, necessitating sustainable alternatives.
• Microbial oils, particularly from Yarrowia lipolytica, present a viable solution due to their composition, low carbon footprint, and ability to use low-cost substrates.

Purpose of the Study:

• To enhance lipid production in Yarrowia lipolytica using a Design-Build-Test-Learn (DBTL) approach.
• To identify and overcome bottlenecks in microbial lipid biosynthesis through metabolic modeling and genetic engineering.

Main Methods:

• Utilized a genome-scale metabolic model to predict and test medium supplements (glutamate, leucine, methionine, threonine).
• Employed genetic interventions including overexpression of key enzymes (ACL, ACC, TS, DGA1) and gene deletions (CEX1, MFE1).
• Applied the Design-Build-Test-Learn (DBTL) cycle for iterative improvement of lipid production.

Main Results:

• Identified critical roles for Acetyl-CoA carboxylase (ACC), ATP-citrate lyase (ACL), Threonine synthase (TS), and Diacylglycerol acyltransferase (DGA1) in lipid biosynthesis.
• Demonstrated the interaction between these genes and intracellular citrate levels for enhanced lipid accumulation.
• Achieved a 200% increase in lipid content (56% w/w) and a 230% increase in lipid yield on glycerol by combining TS and DGA1 overexpression in a modified Y. lipolytica strain (Δmfe_Δcex).

Conclusions:

• Yarrowia lipolytica is a potent microbial cell factory for sustainable fatty acid production.
• The study provides a robust DBTL framework for optimizing microbial lipid biosynthesis.
• This research advances the development of economically feasible and environmentally friendly alternatives to palm oil.