Author Archives: Yongxue Ding

Expression of Recombinant Antibody Fragments: High-Density Fermentation in Multiuse and Single-Use Systems

Single-use fermentors (SUFs) offer dramatic advantages over traditional stainless-steel clean-in-place (CIP)/sterilization-in-place (SIP) fermentors. Single-use technology eliminates the need for steam, chemicals, and water to clean and sterilize stainless vessels, which provides a direct reduction in capital cost and environmental-impact mitigation. Single-use platforms also increase equipment and process flexibility significantly, making it possible to switch campaigns from one product to another in minimal time, while eliminating cleaning and associated validation steps (1). Both Cytiva and Thermo Fisher Scientific offer SUFs that…

Oxygen Control Strategy and Yield of Recombinant Antibody Fragments Produced in Fermentation

Immunoglobulin molecules are used extensively in therapeutic treatments, diagnostic applications, and fundamental academic research. Traditionally, full-length antibodies and smaller fragments such as the recombinant antigen-binding fragment (rFab) are produced through mammalian cell culture. rFabs also are small enough to be produced in Escherichia coli through fermentation (1, 2). Because disulfide bonds cannot be formed efficiently in the reducing cytoplasm of E. coli, rFabs are supplemented most commonly with a signal sequence that directs them to the more oxidizing bacterial periplasm…

Comparative Study of Single-Use and Reusable Fermentors: Production of Recombinant Proteins Through Bacterial Fermentation

Single-use bioreactors have become widely accepted and well established for cell culture applications in the biopharmaceutical industry for over a decade (1). Abbott Diagnostics has moved into this technology already for commercial production of some biologic molecules. However, single-use systems (SUSs) are rarely available for microbial applications, mostly because of the technical challenge in designing cost-effective SUSs that can meet high oxygen transfer needs and remove excessive heat generated during fermentation. Thus, an important part of our biologics manufacturing —…