Quantitative evaluation of the shear threshold on Carthamus tinctorius L. cell growth with computational fluid dynamics in shaken flask bioreactors

• Hydrodynamic stress in shaken flask was quantitively analyzed through CFD simulation.
• Effects of shear stress on the growth and morphological were investigated.
• A threshold was observed at average and maximum shear stress.

Quantitative evaluation of the shear threshold on C. tinctorius L. cell growth is vital for bioreactor system design and optimization of scaled-up industrial cultivation. The present research focused on investigating the effects of shear force on C. tinctorius L. cell growth by computational fluid dynamic (CFD) analysis in shaken flasks. The results revealed that specific cell growth rates were greatly inhibited as the shear force increased from 1.17 to 2.42 Pa. Recovery of viability and aggregation diameter to their normal levels could be implemented after a 4-day adaptation with large fluctuations in physiological state. With further correlation analysis on shear force and C. tinctorius L. growth rate, a threshold value was identified at an average and maximum shear stress of approximately 0.55 Pa (0.06 w/kg) and 4.00 Pa (0.93 w/kg) according to the influence on cell growth. Quantitative data on shear effects can facilitate the design of industrial processes and lead to more rational scale-up in industrial C. tinctorius L. cultivation.