Investigation of parameters affecting a fixed bed bioreactor process for recombinant cell lines

Area of Science:

• Biotechnology
• Bioprocess Engineering
• Cell Culture Technology

Background:

• Mammalian cell culture is crucial for recombinant protein production.
• Fixed-bed reactors (FBRs) offer advantages for cell immobilization and continuous processing.
• Optimizing process parameters is key to maximizing bioreactor productivity.

Purpose of the Study:

• To investigate the impact of five process variables on the productivity of a recombinant antibody production system in an FBR.
• To identify optimal conditions for enhanced antibody yield and production rate.
• To compare the performance of an FBR with a fluidized bed reactor (FBR) system.

Main Methods:

• Utilized a BHK 21 cell line engineered to express a recombinant antibody.
• Employed a fixed-bed reactor (FBR) system with Siran glass beads as porous support.
• Applied a partial factorial experimental design to assess five process variables: bead size, inoculum size, circulation rate, dilution rate, and feed glutamine concentration.

Main Results:

• No single process variable significantly impacted productivity when tested individually.
• A combination of smaller bead and inoculum sizes, higher circulation and dilution rates, and higher feed glutamine concentration markedly increased productivity.
• The FBR system demonstrated superior productivity compared to a fluidized bed reactor system under the tested conditions.

Conclusions:

• Process variable interactions are critical for optimizing recombinant antibody production in FBRs.
• The identified combination of parameters provides a strategy for enhancing bioreactor performance.
• The FBR system, contrary to initial suggestions, proved more effective than a fluidized bed system for this specific application, likely due to factors related to specific growth rate (mu) and volumetric antibody production rate (QsrAb).