Bioreactor Design for Plant Cell Suspension Cultures

Bioreactor Engineering For Recombinant Protein Production Using Plant Cell Suspension Culture

“…Another point to consider is that under gassing conditions, the impeller power input is reduced, and hence the cumulative energy dissipation is expected to decrease according to equation (3). While shear damage resulting from the hydrodynamic forces associated with bubble rupture is believed to be insignificant in plant cell cultures [18,43], there is no evidence indicating shear damage is reduced with increasing bubble aeration rates at a fixed stirrer speed. The suitability of E c as a common basis to quantify the agitationbased shear forces under different bubble aeration rates apparently warrants further investigations.…”

“…Separating and dispersing the cells from the aggregates by mechanical means in a bioreactor (e.g. by increasing bioreactor agitation) is usually not very effective and may lead to cell damage, or even larger aggregates [18]. Addition of pectinase and cellulase, higher cytokinin concentration, or lower calcium concentration in the media may help to reduce the aggregate size [28].…”

“…Cell aggregates may consist of a mixture of highly mitotic and less mitotic cells (the latter usually have greater potential for cellular differentiation into adventitious tissues or organs). Cell aggregation promotes cellular organization and differentiation which is generally believed to benefit secondary metabolite production, although in some cases secondary metabolite production was found to be independent of aggregate sizes, such as ajmalicine production in Catharanthus roseus culture [27] (cited in [18]). It appears what is important for secondary metabolite production may not be the size of the aggregates, but the state of organization and cellular differentiation within the cell aggregates, which may not be entirely dependent on the aggregate size.…”

“…Size of single plant cells is typically in the range of 50-100 m. Suspension cultures normally exhibit various degrees of cell aggregation with the aggregate sizes varying dependent on the plant species, growth stage, and culture conditions. While some plant cells form fine suspensions with few large aggregates (with the largest aggregates smaller than 1 mm), such as N. tabacum [5,23] and Anchusa officinalis [24], others form huge aggregates as large as 2 cm in diameter, as in the case of Panax ginseng suspension culture used in the Nitto Denko ginseng process [25] (cited in [18]). Formation of cell aggregates is mainly due to the tendency of the cells to not separate after division.…”

“…While much of the knowledge derived from the development of plant cell bioreactors for secondary metabolite production are still relevant, issues unique to recombinant protein production will be emphasized in this chapter. New findings since the publications of other recent reviews of plant cell bioreactor [18,19] will be highlighted. Effective bioreactor design and operation assures high productivity which is key to successful bioprocess development.…”