Fermentation process for producing CFAs using Yarrowia lipolytica.

Area of Science:

• Biotechnology
• Microbial Engineering
• Biofuels

Background:

• Cyclopropane fatty acids (CFAs) are valuable compounds with potential applications in biofuels.
• Previous efforts focused on improving CFA production in Yarrowia lipolytica through genetic modification and process optimization.

Purpose of the Study:

• To enhance the production of cyclopropane fatty acids (CFAs) in the oleaginous yeast Yarrowia lipolytica.
• To optimize the heterologous expression of the E. coli fatty acid synthase gene and improve yeast cultivation for higher CFA yields.

Main Methods:

• Heterologous expression of the E. coli fatty acid synthase gene in various Yarrowia lipolytica genetic backgrounds.
• Optimization of cultivation processes, including fed-batch fermentation using crude glycerol as a carbon source.
• Simultaneous overexpression of the E. coli cyclopropane fatty acid synthase gene and the Yarrowia lipolytica LRO1 gene in the JMY6851 strain.

Main Results:

• The engineered Yarrowia lipolytica strains achieved a mean CFA productivity of 43 mg L⁻¹ h⁻¹ on glucose.
• The JMY6851 strain, under optimized fed-batch conditions with crude glycerol, exhibited high lipid accumulation (78% of dry cell weight) and biomass production (56 g L⁻¹).
• Maximal CFA productivity reached 103.3 mg L⁻¹ h⁻¹ at 72.5 hours of cultivation, with CFAs constituting 22% of total lipids.

Conclusions:

• The genetic engineering of Yarrowia lipolytica, specifically the JMY6851 strain, significantly enhances cyclopropane fatty acid production.
• Optimized cultivation strategies, particularly using crude glycerol, improve lipid accumulation and CFA yields, supporting the potential of these yeasts for biofuel feedstock production.