Suspension cultures of
Rubia tinctorum, an anthraquinones (AQs) producer, were grown bothin Erlenmeyer flasks at 100 rpm and in a 1.5 L mechanically stirred tank bioreactor operatingat 450 rpm. The effect of hydrodynamic stress on cell viability, biomass, and AQs productionwas evaluated. Cell viability showed a transient decrease in the bioreactor during the first days,returning to the initial values toward the end of the culture time. The biomass obtained in thebioreactor was 29% lower than that attained in the Erlenmeyer flasks. The H
2O
2 production inthe bioreactor (with peaks at 7 and 10 days) was about 15 times higher than that obtained in theflasks. A clear relationship exists between the maximum concentration of H
2O
2 generated andAQs produced. The AQs content in the bioreactor was 233% higher than that in the Erlenmeyerflasks. The AQs specific productivity in the stirred tank and in the Erlenmeyer flasks was 70.7and 28.5
mol/g FW/day, respectively. This production capability was maintained in the regrowthassays. On the other hand, the negative effects of hydrodynamic stress on viability and biomassconcentration observed in the bioreactor culture were reverted in the regrowth cultures. It canbe concluded that
R. tinctorum suspension cultures are able to grow in stirred tanks at 450 rpmresponding to the hydrodynamic stress with higher concentrations of AQs, which suggest thepossibility of a technological approach taking advantage of this phenomenon.