Regular articleMass production of Ajmalicine by bioreactor cultivation of hairy roots of Catharanthus roseus

•Alternative bioreactors could elevate ajmalicine production.•Non-homogenous distribution of roots and complete submergence was avoided.•Rotating drum and Modified bioreactors with support matrix were attempted.•Polyurethane foam matrix led to highest Ajmalicine productivity of 1.13 mg/ld.

Catharanthus roseus has been known to produce Ajmalicine which is used for treatment of circulatory disorders. Significantly low content of the drug in the natural plant necessitates development of alternative production protocols. Hairy root propagation was considered as a viable alternative. Mass cultivation of the hairy root culture was attempted in several bioreactor configurations; Bubble column, Rotating drum bioreactor, Modified Bubble column with polypropylene (PP) mesh support and Modified Bubble column with Polyurethane foam (PUF) support. Important factors like medium composition, inoculum density, illumination period and aeration rates were optimized before mass propagation of hairy roots. From the data gleaned, the cultivation in rotating drum bioreactor resulted in ajmalicine content of only 4.6 ± 0.4 mg/l. However, the ajmalicine concentration surpassed even that obtained in shake flask (with 34 ± 2.3 mg/l) in a customized bioreactor wherein the hairy roots were anchored onto a polyurethane foam, the highest reported in this scale of cultivation.