Continuous fermentation using high cell density cell recycle system for L-lactic acid production.

Area of Science:

• Biotechnology
• Industrial Microbiology
• Biochemical Engineering

Background:

• Efficient lactic acid (LA) production is crucial for various industries.
• High glucose concentrations pose challenges for microbial fermentation.
• Optimizing fermentation systems is key to improving LA yield and productivity.

Purpose of the Study:

• To establish a high cell density (HCD) continuous fermentation system for lactic acid bioproduction.
• To maximize lactic acid productivity and yield using Lb. delbrueckii NCIM 2025.
• To evaluate the effectiveness of an integrated membrane cell recycling system.

Main Methods:

• Utilized a continuous fermentation system with Lb. delbrueckii NCIM 2025.
• Integrated a membrane cell recycling system with the bioreactor.
• Operated at a maximum dilution rate of 0.36 h⁻¹ and a wet cell weight of 230 g/L.

Main Results:

• Achieved a maximum lactic acid productivity of 34.77 g/L/h.
• Obtained a high lactic acid yield between 0.94-0.98 g/g.
• Demonstrated approximately 34 times higher productivity compared to batch fermentation.

Conclusions:

• The developed HCD continuous fermentation system effectively utilizes high glucose concentrations.
• The integrated membrane cell recycling system enhances LA production efficiency.
• This method presents a cost-effective and sustainable alternative for industrial lactic acid bioproduction.