Evaluation of a high throughput multiparallel stirred bioreactor system using an apple cell line

Area of Science:

• Biotechnology
• Plant Cell Culture
• Bioprocess Engineering

Background:

• Plant cell cultures in bioreactors offer scalable production of secondary metabolites.
• Bioreactor performance is critically dependent on cultivation conditions and design.

Purpose of the Study:

• To investigate the influence of different bioreactor configurations on apple plant cell growth and triterpene production.
• To compare multi-liter stirred-tank bioreactors (STRs) with a small-volume high-throughput parallel system.

Main Methods:

• Evaluated STRs (2-5 L) with varied vessel geometries and impeller types (Rushton, marine, elephant ear).
• Assessed a 240 mL high-throughput parallel system for predictive capability.
• Studied the effect of dissolved oxygen (pO2) cascade controls on cell growth and metabolite yield.

Main Results:

• Significant variations in triterpene content and biomass yield were observed across different bioreactor systems.
• Plant cells exhibited high sensitivity to shear stress (56.2%-63.5% variation coefficient).
• Elephant ear impellers supported stable triterpene accumulation (14.15 mg/g DW) and higher biomass (11.8 g DW/L), likely by reducing shear stress.

Conclusions:

• Bioreactor design and control strategy are crucial for maximizing plant cell growth and secondary metabolite production.
• Small-scale high-throughput systems effectively predict performance at larger scales, serving as valuable process development tools.
• System-specific optimization is essential, as different bioreactor types (e.g., wave, flask) yield distinct results.