Public Thesis Defense of Margaux Thiry

"Establishment, characterisation, optimisation and scaling-up of a Cannabis sativa cell suspension culture"

Summary

Cannabis sativa L. is a multipurpose plant valued for its diverse bioactive compounds and applications in the pharmaceutical, cosmetic, nutraceutical and biomaterial sectors.

This thesis focuses on developing a C. sativa cell culture system as a sustainable platform to produce cannabisins, a group of bioactive compounds with pharmaceutical and cosmetic potential. 

The work started by comparing several commercial and non-commercial Cannabis genotypes and showed that the non-commercial Line 43/178 accumulated higher levels of these compounds and was therefore selected for further development. 

Cell cultures were then established from this genotype and optimised in two stages: first, adjusting the growth medium and plant growth regulators’ combinations to obtain stable, fast-growing calli and cell cultures, and second, identifying the specific culture conditions needed to trigger the production of cannabisins, since the conditions best for growth were not the same as those for the production of the target compounds.

Molecular analyses helped explain this trade-off, showing that different biological pathways were activated depending on the culture medium. 

To further increase production, an elicitation strategy was tested using an enzyme (a fungal laccase) to stimulate a stress response in the cells that enhanced cannabisin accumulation. 

Finally, the whole process, from cell growth to compound production, was successfully scaled up from flasks to bench, technical and pilot scale bioreactors (2, 30 and 300 litres), confirming that the bioprocess could be reliably transferred to larger volumes. 

This work therefore provides a validated proof of concept for producing added-value compounds through the plant cell culture technology, a controlled and sustainable alternative to field cultivation.

Jury members

Prof. Stanley Lutts, UCLouvain (Supervisor)
Dr. Gea Guerriero, LIST (Supervisor)
Prof. Frédéric Gaspart, UCLouvain (Chairperson)
Prof. Charles Hachez, UCLouvain (Secretary)
Dr. Jenny Renaut, LIST 
Prof. Muriel Quinet, UCLouvain
Prof. Marie France Herent, UCLouvain
Prof. Nathalie Guivarc’h, Université de Tours