Industrial-scale production of basil hairy roots in a 1000-L bioreactor and advanced downstream processing for the preparation of cosmetic ingredients.

Hairy root cultures offer a sustainable alternative to field-grown plants for the production of bioactive compounds, but their translation to industrial-scale processes is limited by the challenges of high-volume cultivation and downstream processing. In the current study, a large-scale production pipeline for basil (Ocimum basilicum) hairy roots, a rich source of specialized bioactive metabolites, is described. The production of hairy root biomass was optimized by developing a robust and scalable cultivation protocol, enabling consistent and reproducible growth in bioreactor systems with working volumes of up to 1000L. The entire production pipeline from initial Petri dish cultures to industrial-scale bioreactors was established by adopting a systematic, stepwise methodology, ensuring process reliability and scalability. A customized bioreactor with controlled aeration maintained biomass integrity and metabolic stability during long-term axenic cultivation, yielding 96.4kg of biomass fresh weight within 84 days. Complementary solvent-based extraction and pulsed electric field processing allowed the recovery of metabolites with a broad range of polarities. Untargeted metabolomics revealed a chemically diverse profile comprising primary metabolites, phenolic acids, flavonoids, terpenoids and triterpenoids with relevance for cosmetic applications. These results demonstrate the feasibility of industrial-scale basil hairy root cultures and support their use as a source of plant-derived cosmetic ingredients.