In vitro cultivation of hairy roots of Plumbago rosea L. in a customized Reaction kettle for the production of plumbagin-An anticancer compound

Biosynthesis of plumbagin using hairy root cultures of Plumbago rosea L. can be made economical only by scaling-up cultures in suitable vessels under conditions optimal for maximum yield of biomass and plumbagin. However, the major limitation faced in the scaling-up of hairy roots is the development of appropriate culture vessels that will allow maximum growth of interconnected root mat with less shear stress. Design of economical and low energy requiring scaling-up culture system for hairy roots with emphasis on physical parameters like inoculum state, nutrient mixing, aeration, inoculum support etc., is very important for root cultures. A novel, culture vessel model using a Reaction kettle (2 L) was attempted for successful scaling-up of P. rosea hairy roots. The roots cultured in Murashige and Skoog basal liquid medium for 25 days in a Reaction kettle (2 L) customized with a polypropylene mesh for support and a fish tank aerator for aeration yielded maximum biomass and plumbagin. Twelve-fold increase in root biomass with highest plumbagin content of 1.5% dry weight (DW) was obtained in Reaction kettle whereas, shake flask cultures produced only five fold biomass enhancement with 1.1% DW plumbagin. The present experiments demonstrated the suitability of the customized Reaction kettle with adequate filtered air for the scaling-up of hairy root cultures for secondary metabolite production. This is the first report on exploiting a Reaction kettle for in vitro scaling-up of organ cultures. (C) 2016 Elsevier B.V. All rights reserved.