Ma. Subroto et Pm. Doran, PRODUCTION OF STEROIDAL ALKALOIDS BY HAIRY ROOTS OF SOLANUM AVICULAREAND THE EFFECT OF GIBBERELLIC-ACID, Plant cell, tissue and organ culture, 38(2-3), 1994, pp. 93-102
Cultures of Solanum aviculare hairy roots were established after trans
formation with Agrobacterium rhizogenes A4. High levels of steroidal a
lkaloids measured as solasodine equivalents were produced in shake-fla
sks and bioreactor, even though relatively low concentrations are foun
d in roots in vivo. In shake flasks the maximum alkaloid yield was 32
mg g(-1) dry weight; in a 3-1 air-driven bioreactor the yield was 29 m
g g(-1). These yields represent a 5-fold increase over previous report
s for in vitro production, and are comparable with levels found in the
aerial parts of intact S. aviculare plants. Production of steroidal a
lkaloids was growth-associated. High sugar levels at stationary phase
and insensitivity to increased levels of medium components suggest tha
t root cultures were limited by oxygen mass-transfer. In Petri-dish cu
lture with and without exogenous gibberellic acid, root length and num
ber of root tips increased exponentially; growth proceeded with a cons
tant length per root tip of about 35 mm. Addition of gibberellic acid
enhanced growth but reduced the specific steroidal-alkaloid level. Tak
ing into account both growth and alkaloid yield, accumulation of stero
idal alkaloids was improved by about 40% at gibberellic-acid concentra
tions of 10 and 100 mu g l(-1).