Design of a culture system to study anthraquinones elicitation under shear stress in Rubia tinctorum cell suspension cultures

BUSTO VD; CALABRO A; RODRÍGUEZ TALOU J; GIULIETTI AM; MERCHUK J

Rosario

Simposio; VII Simposio Nacional de Biotecnología REDBIO-Argentina; II Congreso Internacional-REDBIO-Argentina; 2009

REDBIO Argentina

Shear stress has been used as a mechanical elicitor to induce secondary metabolites accumulation in many plant species. We found that shear stress elicited anthraquinones (AQs) production in Rubia tinctorum suspension cultures growing in a stirred tank bioreactor operating at 450 rpm. In order to study mechanical elicitation mechanisms several experimental units are necessary. In this way the aim of this work was to design a down-scaled and simple culture system which allows replacing bioreactor experiments. To induce a similar intensity of shear stress comparing to the one reached using the bioreactor, 100 mL baffled shake flasks were agitated on an orbital shaker at 360 rpm during 14 days. Controls were carried out in 100 mL baffled flasks agitated at 100 rpm. All the cultures were grown at 25 °C in presence or absence of light. Biomass concentration, cell death and AQs production were evaluated. When cells were cultured at 360 rpm, a decrease in biomass concentration (28%) was observed compared with control cultures. Loss of cell viability measured as Evans Blue uptake increased 60% and 40% after 7 days of shear stress in presence and absence of light respectively. AQs accumulation increased up to 155% and 216% compared with control after 14 days of shear stress in presence and absence of light respectively. These results show that baffled flasks system elicit AQs production in a similar way as bioreactors in R. tinctorum suspension cultures and could be a potential strategy useful to study the mechanical elicitation mechanisms.