Abstract
The actinomycete Lentzea aerocolonigenes produces the antitumor
antibiotic rebeccamycin. In previous studies the rebeccamycin production
was significantly increased by the addition of glass beads during
cultivation in different diameters between 0.5 – 2 mm and the induced
mechanical stress by the glass beads was proposed to be responsible for
the increased production. Thus, this study was conducted to be a
systematic investigation of different parameters for macroparticle
addition, such as bead diameter, concentration and density (glass and
ceramic) as well as shaking frequency, for a better understanding of the
particle induced stress on L. aerocolonigenes. The induced stress for
optimal rebeccamycin production can be estimated by a combination of
stress energy and stress frequency. In addition, the
macroparticle-enhanced cultivation of L. aerocolonigenes was combined
with soy lecithin addition to further increase the rebeccamycin
concentration. With 100 g L-1 glass beads in a
diameter of 969 µm and 5 g L-1 soy lecithin a
concentration of 388 mg L 1 rebeccamycin was reached after 10 days of
cultivation, which corresponds to the highest rebeccamycin
concentrations achieved in shake flask cultivations of L.
aerocolonigenes stated in literature so far.