Production of recombinant human granulocyte‐macrophage colony‐stimulating factor in thermoinducible
E. coli
: Tuning inclusion body architecture and
Ximena Gómez‐Gil, Norma A Valdez‐Cruz, Sara Restrepo‐Pineda, Nuria Sánchez‐Puig, Rafael Vázquez‐Duhalt, Rubén D Cadena‐Nava, Néstor O Pérez, Mauricio A Trujillo‐Roldán Abstract
BACKGROUND
Recombinant protein expression in Escherichia coli frequently results in the formation of inclusion bodies (IBs), which provide high protein accumulation but often require additional steps to recover functional protein. Although culture conditions strongly influence IB physicochemical and structural characteristics, the impact of dissolved oxygen tension (DOT) remains poorly understood in thermoinducible expression systems widely used for industrial production.
RESULTS
Recombinant human granulocyte‐macrophage colony‐stimulating factor (rHuGM‐CSF) was produced in E. coli using the thermoinducible λpL‐cI857 system. Post‐induction DOT significantly affected recombinant rHuGM‐CSF production, size, and structural properties of IBs. Cultures maintained at low DOT (5–10%) showed the highest volumetric and specific protein production, despite lower specific growth rates compared to cultures at 30% and 70% DOT. Low DOT also produced larger IBs, with reduced amyloid‐like content and higher susceptibility to proteolytic degradation and partial solubilization, indicating a less compact aggregate structure. In contrast, higher DOT (30–70%) favored faster early post‐induction accumulation but resulted in smaller, more rigid IBs with increased resistance to solubilization and proteolysis.
CONCLUSION
Post‐induction DOT is an effective process parameter for modulating IB morphology, aggregation state, and recombinant protein yields, providing practical strategy to improve recombinant protein downstream recovery in thermoinducible E. coli bioprocesses. © 2026 The Author(s). Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).