Isoflavonoids production in cell suspension cultures of Pueraria tuberosa grown in shake flasks and bioreactor

The tubers of Pueraria tuberosa (Roxb.ex.Willd.) DC contain isoflavonoids, puerarin, daidzein, genistein and genistin, which are under clinical trials against cancer, osteoporosis and cardiovascular diseases [1]. Plant cell cultures have potential to produce the molecules of interest and attempts have been made to increase their accumulation. The cultures were maintained in MS medium containing 0.1mg/l 2,4,5-T and 0.1mg/l kinetin. The cells were analysed for isoflavonoids content using HPLC [2]. Up to 8-folds (6.6mg/l) increased isoflavonoids content was recorded in the cultures grown in MS medium modified with nitrogen and supplemented with 1.0mg/l of kinetin. Isoflavonoids accumulation was further improved by 48 hours of elicitors treatment at the stationary phase. Yeast extract, 150mg/l was optimal for isoflavonoids production yielding ˜11-folds (10mg/l) isoflavonoids. Ethrel at 100µM after 48 hours treatment, increased 14-folds (˜12mg/l) isoflavonoids accumulation in cell cultures.

Further, the addition of 1.0mg/l 2iP in maintenance medium resulted in about ˜32-folds increase in the production of isoflavonoids. A maximum yield of isoflavonoids ˜82-folds (80mg/l) was obtained in cultures grown at 0.1mg/l morphactin and 5.0mg/l of 2iP. The cultures were scaled-up to 3L flasks and 2L stirred tank bioreactor. The increase in isoflavonoids, as obtained in this research, was unique to cell cultures grown in the medium containing morphactin.

References: 1. Dixon R.A., Sumner L.W. (2003) Plant Physiol 131:878–885. 2. Goyal S., Ramawat K.G. (2008) Plant Growth Regul (DOI 10.1007/s10725–008–9271-x).