Hydrodynamic stress and limonoid production in Azadirachta indica cell culture

Production of anti‐inflammatory compounds in Sphaeralcea angustifolia cell suspension cultivated in stirred tank bioreactor

“…Maximal biomass of cell suspension in culture from S. angustifolia obtained in the bioreactor was 1.42-fold superior to that generated in the cultures developed in Erlenmeyer flasks [11]; nevertheless, the max was lowest. This result is consistent with that described for other species, such as B. vulgaris [13], A. indica [15], and Burcera linanoe [22]; maximal biomasses were obtained in the stirred tank-type bioreactor rather than in Erlenmeyer flasks. The stirred bioreactor tank is considered a good option for plant cell culture.…”

“…The Reynolds number values calculated for the cell culture exposed to 100 and 200 rpm were 361 and 958, respectively, indicating that the cell culture was in a laminar flow regime, while at 400 rpm, the Reynolds value was 2645, indicating that the cells were in a transitional flow regime. The culture of cells of S. angustifolia at 400 rpm exhibited a decrease in its growth, in its viability, and showed lowest production of sphaeralcic acid; these negative effects can be attributed to the increase in the hydrodynamic stress condition present in the tank at the agitation speed of 400 rpm, mainly in Reynolds stress and in turbulent eddy length, as has been suggested for the cultivation of A. indica cells . Busto et al.…”

“…In both cases, these problems affected the cellular viability in the cultures. At the highest stirring rate, foam formation and cell adhesion were also observed on the wall of the bioreactor and these could limit the absorption of nutrients from the culture medium by the cells, altering the cellular metabolic processes and the production of secondary metabolites .…”

“…In contrast, for Azaridachta indica cell suspension, it was reported that when these were cultivated in a stirred tank‐type bioreactor, an agitation speed of 800 rpm was detrimental for cell growth and the production of limonoids, whereas the cells reached a maximal growth of 16 g of dry weight (DW)/L with an agitation speed of 400 rpm. The harmful effect at 800 rpm was evidenced by the decreasing cell viability associated with the presence of small eddies .…”

Establishment and triterpenoid production of Ocimum basilicum cambial meristematic cells

“…Considering the negative influence of hydrodynamic stress on plant cells, most pronounced by stirring (Kieran et al 1997), it appears reasonable to favour non-stirred cultivation systems like wave wDBRs. However, it was recently postulated that careful adjustment of stirring speed may enhance limonoid production in Azadirachta indica cell culture (Villegas-Velásquez et al 2017). During cultivation of CMCs in a stirred tank reactor at 120 rpm stirring speed, the highest productivities of oleanolic and ursolic acid were determined at 2.26 mg/ml*d and 2.10 mg/ml*d after 13 days cultivation, respectively (Fig.…”