GIULIETTI Ana Maria
2. Effect of Shear Stress on Anthraquinones Production by Rubia tinctorum suspension cultures
BUSTO, V; RODRIGUEZ TALOU, J; GIULIETTI, A. M.; MERCHUK, J.C
Año: 2008 p. 175 - 175
Abstract (bp 0702370) Suspension cultures of Rubia tinctorum, an anthraquinones (AQs) producer, were grown both in Erlenmeyer flasks at 100 rpm and in a 1.5 L mechanically stirred tank bioreactor operating at 450 rpm.The effect of hydrodynamic stress on cell viability, biomass and AQs production was evaluated. Cell viability showed a transient decrease in the bioreactor during the first days, returning to the initial values towards the end of the culture time. The biomass obtained in the bioreactor was 29% lower than that attained in the Erlenmeyer flasks. The H2O2 production in bioreactor (with peaks at 7 and 10 days) was about 15 times higher than that obtained in the flasks. A clear relationship exists between themaximum concentration of H2O2 generated and AQs produced. AQs content in the bioreactor was 233% higher than in Erlenmeyer flasks. The AQs specific productivity in the stirred tank and in the Erlenmeyer flasks was 70.7 and 28.5 ìmol/g FW/day respectively. This production capability was maintained in the regrowth assays. On the other hand, the negative effects of hydrodynamic stress on viability and biomass concentration observed in the bioreactor culture were reverted in the regrowth cultures. It can be concluded that R. tinctorum suspension cultures are able to grow in stirred tanks at 450 rpm responding to the hydrodynamic stress with higher concentrations of AQs, which suggest the possibility of a technological approach taking advantage of this phenomenon.