Yield Enhancement Strategies for Enhancement of Indole Alkaloids in Hairy Root Cultures of Catharanthus Roseus

Late exponential phase of hairy root cultures of Catharanthus roseus cultivated in a statistically optimized medium were treated with permeabilizing agents (DMSO, Triton X-100, n-hexadecane and Tween 80) to establish the effect of their concentrations and exposure time on the biomass and major alkaloid(ajmalicine) yield & productivity. The permeabilizing agents TritonX-100(0.1% v/v) and nhexadecane( 2%v/v) led to 98% increase in the specific yield of ajmalicine in the roots. Statistical techniques were used to determine the significance of various treatments and their response on the yield of the secondary metabolite. Both DMSO and Triton X-100 were found to be useful in effluxing ajmalicine into the medium resulting in a 12 fold and 16 fold increase respectively. The viability assay revealed the tolerance of the roots to all permeabilizing agents but tween 80.It can be concluded from the studies that permeabilizing factors were highly instrumental in enhancing the biomass and alkaloid concentrations and rates during the propagation of hairy root cultivation of Catharanthus roseus. Such a protocol of application of non lethal permeabilizing agents to leach out the key plant secondary metabolites can be extended to mass scale hairy root cultivation.