Comprehensive study of a novel Catharanthus roseus cell line for medicinal alkaloids production

The Catharanthus roseus herbs are the source of pharmaceutical alkaloids, including the antihypertensive ajmalicine and antineoplastics vincristine and vinblastine, whose global shortages have recently compromised medical therapies. Suspension culture represents a sustainable alternative for production but requires well-characterized cell lines for efficient bioprocess development. In this study, a suspension culture system of the novel CRBY-1 (Catharanthus roseus Bright Yellow-1) cell line has been established and comprehensively characterized. Cell proliferation and morphology analyses showed predominantly homogeneous oval cells (~ 108 μm) forming small aggregates of 1-4 cells, achieving a maximum dry biomass of 10 g/L. Growth kinetics revealed a specific growth rate of 0.49 d⁻¹, doubling time of 1.3-1.4 d, and a cell respiration rate of 0.0066 mg O₂ g⁻¹ s⁻¹. Nutrient uptake profiling indicated that phosphate and oxygen, rather than carbon, became limiting during mid-culture, influencing biomass formation and nitrogen assimilation. Alkaloid production analysis showed that CRBY-1 synthesized both ajmalicine and catharanthine at notable levels. For ajmalicine, the cell line produced 55 mg per kg of biomass inside the cells and 13 mg per litter in the culture medium. For catharanthine, production reached 133 mg per kg of biomass intracellularly and 13 mg per litter extracellularly. These values exceed those previously reported for callus cultures and plant tissues. Vincristine and vinblastine, however, were not detected in the suspension cultures. The cell line exhibited growth-associated alkaloid production, stable morphology, and high metabolic activity, reinforcing its potential for future scale-up in bioreactor systems. These findings provide critical insights for the future valorisation of CRBY-1 in sustainable, scalable production of high-value alkaloids and or other bioactive molecules.