Considerations Regarding High Oil Density Bioreactor-Scale Fermentations of Yarrowia lipolytica Using CFD Modeling...

Area of Science:

• Biotechnology
• Chemical Engineering
• Microbiology

Background:

• Waste cooking oil is an abundant, low-cost hydrophobic feedstock for microbial biotransformation.
• Current hydrophobic substrate fermentations are typically small-scale or use low substrate concentrations, limiting efficiency.
• High-oil-density fermentations offer reduced volumetric requirements but present mixing and mass transfer challenges.

Purpose of the Study:

• To investigate the feasibility and challenges of high-oil-density fermentations using waste cooking oil.
• To model three-phase bioreactors at bench and pilot scales using computational fluid dynamics (CFD).
• To conduct fermentations with high waste cooking oil concentrations (up to 50% v/v).

Main Methods:

• Computational fluid dynamics (CFD) modeling of 3 L and 4000 L bioreactors.
• Bioreactor fermentations using Yarrowia lipolytica strain L36DGA1.
• Testing substrate loadings from 5% to 50% (v/v) waste cooking oil.

Main Results:

• CFD models simulated mixing and mass transfer in three-phase bioreactors at different scales.
• Successful fermentations were achieved with up to 50% (v/v) waste cooking oil, a high concentration in literature.
• The study identified key challenges and considerations for scaling up high-oil-density fermentations.

Conclusions:

• High-oil-density fermentation using waste cooking oil is feasible at bench and pilot scales.
• CFD modeling is a valuable tool for addressing scale-up challenges in such fermentations.
• This research supports the industrial implementation of efficient lipid-derived fermentation products.