The Effects of Initial Hairy Root Morphology, Aeration Rate and Stirring Period on Plumbago indica L. Hairy Root Culture in Stirred Tank Bioreactor

Abstract

The objective of this research was to study the scale-up of genetically transformed hairy root cultures of Plumbago indica L. in stirred tank bioreactor. The hairy root transformed with Agrobacterium rhizogenes strain K599 was cultivated in 5 L stirred tank bioreactor containing 3 L of half strength Murashige and Skoog (½ MS) medium supplemented with 2% (w/v) sucrose under dark condition at 25±2 °C and stirred at 80 rpm. The initial inoculums density of hairy root was 2% (w/v). After culturing hairy root in stirred tank bioreactor for 20 days, root morphology, aeration rate and medium circulated time affected growth of hairy root and plumbagin content. Using a small root clump and 0.6 volume of air per liter of medium per minute (vvm) aeration rate gave the higher in growth and the higher in plumbagin production than using a large root clump and the aeration rate of 0.3 vvm. For medium circulated duration, the all-time stirred at 80 rpm during 20 days of culture exhibited higher hairy root growth but lower plumbagin production than 16 days stirred followed by 4 days of pause.