Process optimization for the probiotic strain bifidobacterium longum subsp. longum NCC 2705

  • Rafael Viana Barge Bouçon Ribeiro (Student)

Student thesis: Master's Thesis


It is essential that the cultivation medium guarantees a high yield of highly concentrated, stable, and functional live cells in order to deliver probiotics in products. The objective of this project was the optimization of the growth medium to cultivate a probiotic strain, at a laboratory scale, a fundamental work step for the industrialization of a product. The target was to achieve a concentration of live cells of 2.0x1011 CFU/g, similar to the probiotic clinical batch, in culture powder. A screening was performed, in BioLector® and Dasgip® bench bioreactors, using a yate’s design and “one-factor-at-the-time” experiments, with the purpose of identifying which factors and parameters influenced the growth of the probiotic strain and for this reason should be part of the final stage optimization experiments. The pH value and concentrations of the carbon source, nitrogen source and S were selected, whereas T, U, V and X seemed to play a minor role in the probiotic strain growth. Substrates and concentrations were then optimized. The optimized process parameters and medium composition gave the maximum biomass concentration of 2.12x1011 CFU/g, fulfilling the project target on viability.
Date of Award8 Jul 2021
Original languageEnglish
Awarding Institution
  • Universidade Católica Portuguesa
SupervisorGuenolee Eliane Marie Prioult (Supervisor) & Murielle Gresset (Supervisor)


  • Probiotics
  • Growth medium optimization
  • Screening
  • Bioreactors
  • Design of experiment


  • Mestrado em Engenharia Alimentar

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