Mass propagation of Helianthus annuus suspension cells in orbitally shaken bioreactors : improved growth rate in single-use bag bioreactors

Stirred tank-bioreactors made of glass or steel, wave-mixed and orbitally shaken bag bioreactors have all proven to be suitable for the rapid development and commercial production of bioactive compounds with plant cell suspensions. Although these bag bioreactors are characterized by reduced foam formation and less flotation in comparison to stirred systems, their power input is limited. Engineering parameters such as mixing time, oxygen transfer and power input are dependent on the viscosity of the liquid and thus, investigations with plant cell suspensions are necessary. However, to save time and achieve better controllability, sodium carboxymethyl cellulose (Na-CMC) solutions in concentrations ranging from 1 to 20 g·L−1, with viscosities of between 0.005 and 0.4 Pa, were identified as appropriate model systems for mimicking plant cell suspensions with packed cell volumes (PCV) of between 30 and 70% and similar viscosities. The current study has shown that it is possible to transfer a Helianthus annuus cell suspension process from an orbitally shaken CultiBag RM 1 L to a CultiBag RM with a 10 L working volume by adjusting the operating parameters to achieve a constant kLa value. A maximum specific growth rate μmax of around 0.25 d−1 was achieved, which corresponds to optimized data for shake flasks and even exceeds the growth rate for stirred glass-bioreactors