Rhamnolipids (RL) are widely used in areas such as oil recovery and bioremediation, but their industrial production has long faced key challenges in the scale-up stage, including poor scalability and reproducibility. Improper scale-up processes may lead to variations in microbial products, thereby compromising overall process yield and reproducibility.
Researchers used constant impeller tip speed as a robust scale-up strategy for RL production, transitioning from a 1.5 to a 5 L bioreactor. Oxygen transfer coefficient was significantly improved, alleviating the oxygen-transfer bottleneck, enabling more efficient aerobic activity. Biomass of bacteria concentrations remained satisfactory across scales, indicating that constant impeller tip speed minimized shear forces, ensuring uniform mixing while did not compromise cell integrity.
RL yield increased by approximately 22%, reaching a final RL concentration of 16.48 ± 0.02 g/L. Although the initial scale-up phase temporarily suppressed growth due to oxygen limitation, the cells successfully redirected their metabolic priorities from rapid proliferation to efficient product synthesis. This strategy provides an effective engineering approach to address the scalability challenge in RL production by optimizing both oxygen transfer and shear control.
DOI:10.1007/s43393-025-00420-w