Antonio Roldao, Ph.D., Senior Scientist, Animal Cell Technology Unit, Instituto de Biologia Experimental e Tecnológica (iBET) will be speaking on “Bioprocess Engineering of Insect Cells for Accelerating Vaccines Development” at the 10th Annual Optimising Expression Platforms conference, 15-16 November 2017, as part of the 9th Annual PEGS Europe event in Lisbon, Portugal. Below is a recent interview.

Antonio Roldao is a Chemical Engineer with a Ph.D. in Engineering and Technology Sciences - Systems Biology (2010) from ITQB-UNL (Portugal), and from 2010 to 2014 he was a senior researcher and director of fermentation technology at SysBio group headed by Dr. Jens Nielsen at Chalmers University of Technology (Sweden). Since 2014 he is a senior researcher at the Animal Cell Technology Unit headed by Prof. Paula Alves and Prof. Manuel Carrondo at at iBET / ITQB-NOVA (Portugal) and since 2015 he is “Investigador FCT” at iBET / ITQB-NOVA, Portugal. Antonio Roldao has been awarded with several research grants, including the AForsk research grant (2012), the J. Gust. Richert Foundation research grant (2013), the FCT “Investigador” grant (2014) and the FCT exploratory research project (2014). Author of 18 scientific manuscripts in peer-reviewed journals, author/co-author of 7 book chapters/conference proceedings; over 25 oral and poster communications. Antonio Roldao has been involved in many Portuguese and EU funded research projects, including "TRANSVAC2" (2017 – 2021), "EDUFLUVAC" (2013 – 2017), iNOVA4Health (since 2015), "Renewable Energy: an advanced Bio-Platform for 1-Butanol Production in Yeast" (2013 – 2015), "Integrated Bio-process Engineering Platform for Biobutanol Production" (2012 – 2014), "BACULOGENES – Baculovirus Vectors for Gene Therapy" (2006 – 2009), “Novel strategies for a safe rotavirus vaccine” (2003 – 2005), and "Genetics, Stoicheometry and Kinetics of Multiple Protein Assembly: the case for a Rotavirus Like Particle" (2005 - 2007). Current research focuses on the development of novel complex biologics with impact in Human Health, e.g., VLP-based vaccines against infectious diseases such as Influenza and Dengue. To accomplish such objectives, bioprocess engineering and bottom-up systems biology approaches are combined with process monitoring and product characterization, thus undoubtedly fastening the generation of such products.

Improving Protein Expression Yields
with Adaptive Evolutionary Engineering
and Protein Production Technologies


How can adaptive evolutionary engineering improve protein expression yields?


  • Increased cell growth and fitness as desirable criteria
  • Long-term adaptation towards nutrient sources and environmental stresses, for example, increase cell fitness (e.g., production of target protein)
  • Cell metabolic alterations lead to increased robustness of a cell line
  • Several selective mutations occur in AEE cells, some of which are associated with altering the translation apparatus for improved protein expression


What novel protein production technologies and producer hosts have shown the greatest promise in optimising expression processes alongside classical systems?


Production technologies

  • Upstream process development:
    • Bioreactor systems (stirred tank and Wave bioreactors), types (stainless-steel or single-use) and operation modes (fed-batch and perfusion)
    • Microcarrier-based technology
    • Mathematical models (deterministic, stochastic and hybrid) based on mass transfer balances and thermodynamics
    • Design of novel/reappraised monitoring and control technologies (e.g., 2D-fluorometry)
  • Downstream process development:
    • Continuous and multi-column chromatographic purification systems
    • Expanded bed adsorption and radial-flow chromatography
    • End-to-end single-use purification platforms
  • Molecular biotechnology and synthetic biology:
    • Site-specific gene integration using recombinase-mediated cassette exchange systems
  • Omics-based approaches:
    • Transcriptomics
    • Metabolomics (including HPLC, 13C/1H-NMR and GC-MS)
    • Fluxomics (including 13C-based Metabolic Flux Analysis)

Producer hosts

  • Insect cells (e.g., Sf-9 and High five cell lines)
  • Mammalian cells (e.g., Vero and CHO cell lines)
  • Yeast


What are the most persistent challenges with accelerating biologics manufacturing and how might they be overcome?



  • Product quantity and quality
  • Process robustness

Overcoming the challenges

  • New/revamped expression hosts using synthetic biology
  • Continuous biomanufacturing by integration of USP and DSP
  • Mathematical/statistical tools for rational DoE and process control/monitoring
  • Robust analytical methods for product quality assessment (e.g., MS-based technologies)


What areas will earn the most attention over the next few years across the protein expression field?


  • Process intensification by continuous integrated biomanufacturing for both upstream and downstream bioprocesses
  • Single-use bioreactors and purification systems
  • Application of omics technologies
  • From adherent cells to suspension
  • From low cell density to high cell density
  • Stable vs. transient protein production platforms
  • Virus-like particles for multi-scale purposes (as immunogens, as scaffolds, for antibody and drug screening, and as nanocarriers in gene therapy applications)

To learn more about Dr. Roldao'’'s presentation and the PEGS Europe Summit, visit: