Polyamine and methyl jasmonate-influenced enhancement of betalaine production in hairy root cultures of Beta vulgaris grown in a bubble column reactor and studies on efflux of pigments

Hairy root cultures of red beet (Beta vulgaris) were grown in 3 1 bubble column reactor for studying growth and pigment production under the influence of polyamines (PA) and elicitor treatment. Earlier studies with shake flask cultures had shown that combined feeding of spermidine (spd) and putrescine (put) (each 0.75 mM) significantly enhanced betalaine productivity in hairy root cultures of red beet. The present study has been focused on betalaine production in 3 1 bubble column bioreactor where the growth pattern and betalaine synthesis under the influence of similar levels of polyarnines were followed. A combination of spermidine and putrescine fed to the roots each at levels of 0.75 mM efficiently increased growth and pigment production resulting in 1.23-fold higher biomass (39.2 g FW l(-1)) and 1.27-fold higher betalaine content (32.9 mg g(-1) DW) than control. Treatments with various levels of elicitor-methyl jasmonate (MJ), though progressively retarded biomass, at 40 muM level resulted in a significant increase in betalaine content resulting in 36.13 mg g(-1) DW which was 1.4-fold higher than the control. Further higher concentrations of methyl jasmonate treatments supported high as well as rapid accumulation of betalaines, the overall betalaine productivity was hampered mainly because of the inhibitory action on biomass. Pigment release studies with cetyl trimethyl ammonium bromide (CTAB) resulted in optimization of concentration for better efflux of betalaines without showing any inhibitory effect on hairy root viability. These studies on product enhancement and on-line extraction of pigment are useful for developing a bioreactor system for betalaine production using B. vulgaris hairy root cultures. In particular the use of elicitors and efflux studies provide an insight for integrating unit operations and developing a process for continuous operation and higher production of phytochemicals. (C) 2003 Elsevier Ltd. All rights reserved.