Induction temperature impacts the structure of recombinant HuGM-CSF inclusion bodies in thermoinducible E. coli

Background: The temperature upshift has been widely used as an induction system to produce recombinant proteins (RPs). However, thermoinduction could affect bacterial metabolism, RP production, and RP aggregation. Understanding the structure and functionality of those aggregates, known as inclusion bodies (IBs), is a research area of interest in bioprocesses being scarcely studied under thermoinduction. Here, we describe the effect of the thermoinduction (39 degrees C or 42 degrees C) on the production of the recombinant human granulocyte-macrophage colony-stimulating factor (rHuGM-CSF) using Escherichia coli W3110 under the system lambda pL/cI857. Results: Results indicated that at 39 degrees C, the production of biomass was almost doubled as well as the acetate accumulation compared to 42 degrees C. Cultures thermoinduced at 42 degrees C improved 1.5-fold the total protein over biomass yield and 1.25-fold the RP over total protein yield. Furthermore, 42 degrees C accelerated the onset of IB formation, changing its architecture. Additionally, IBs formed at 42 degrees C were less soluble and presented higher disorderly structures compared with IBs formed at 39 degrees C, enriched in alpha-helix and amyloidal-like structures. Conclusions: This study highlights the observation that IBs attain different architecture in response to small changes in environmental conditions, such as the induction temperature, being this helpful information to improve thermoinduced bioprocesses. (c) 2022 Pontificia Universidad Cat & oacute;lica de Valparaiso. Production and hosting by Elsevier B.V.