Mixing and oxygen transfer in a rocking bioreactor for cultivated meat production

In the cultivated meat industry, rocking bioreactors have emerged as a promising solution for large-scale cell cultivation, offering advantages such as disposability, cost-effectiveness, and scalability. To ensure proficient cell growth, it is essential to optimize mixing and oxygen transfer while minimizing shear stresses. However, the performance of the rocking bioreactor is still not well understood due to their short history in the market and wide range of geometries and operating conditions. In this study we explore the detailed flow features and their influence on the degree of mixing, oxygen transfer coefficient and shear stresses inside the bioreactor under various operating conditions, using the Basilisk open-source platform to develop a versatile direct numerical simulation toolkit. While intuition might suggest that increased agitation should lead to enhanced transport, we find numerous exceptions to this strategy, which we pinpoint to specific characteristics of the induced fluid flow. We are also able to identify the transitional regime from laminar to turbulent flow, the latter of which may be generally undesirable for cultivated meat production. Our findings are expected to provide guidelines for designing and operating bioreactors for the cultivated meat industry.