Fed-Batch Operational Strategies for Efficient and Robust Pichia Pastoris Cultivations Achieving High Cell Densities.

Once a Pichia pastoris (Komagataella phaffii) producer clone is constructed for recombinant protein production (RPP), a proper design of a fermentation strategy becomes essential to maximize yields and productivity. Within the development of bioprocess technology, several strategies have been proposed based on a broad range of different operational conditions. Such is the case of the fed-batch operation mode, which has become the most extended in the industry. Concretely, μ-stat fed-batch has been widely used since it allows the achievement of pseudo-steady-state conditions for specific rates during the fed-batch phase. This approach allows for reaching and maintaining optimal conditions, obtaining relevant improvements in yields and productivity parameters toward robust and reproducible bioprocesses.Additionally, in this chapter is described the implementation of advanced cultivation strategies based on the application of stress-based approaches, such as carbon-starving and oxygen-limiting conditions, which have shown to be promising methodologies with outstanding results.