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The plant Stizolobium hassjoo which grows in Taiwan is adopt-
ed as an investigation system. The callus was induced from the
leaves with MS medium. The aim of this work is to produce the
L-DOPA (L-dihydroxyphenylalanine) by suspension culture of S.
hassjoo cells. Suspension cultures were conducted mainly in 250
ml Erlenmeyer flask with initial working volume of 75 ml
medium. During suspension culture, cell volume (Settling volume
S.V.) concentrations of L-DOPA and L-tyrosine, the activity of
Phenoloxidase (P.O.) and the residual sucrose concentration
were determined. Generally, the trend of increase of S.V. and L-
DOPA was the same. This indicates that the more the growth of
the cell the higher the production of L-DOPA. A fed-batch
culture of suspension cells was conducted with an aim of
elasting the cell growth by feeding the medium to meet their
demand. It was found that the concentration of L-DOPA increased
1.63 folds compared to that not conducting fed-batch culture.
Biotransformation of L-DOPA from L-tyrosine was carried out by
entrapping the 7 day cells of S.hassjoo in Ca-alginate beads
whose size was approximately 3.5 mm in diameter. The percentage
transformation of tyrosine was 27% in 22 hr reaction. The cor-
responding percentage of L-DOPA was 14% at the initial dosage
of 2 mM L-tyrosine.
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