Effects of Shear Stress on Plant Cells in a Bioreactor

Effects of Shear Stress on Plant Cells in a Bioreactor 

The effect of shear stress on the pigment content, i.e., its specific production, of the Perilla frutescens cells in the reactor is shown in Figs. 3 A and 3B. The anthocyanin content was relatively high at an average shear rate below 30 s 1 or an impeller tip speed below 8 dm s-1. At higher shear rates, the pigment content of the cultured cells showed an obvious decrease. The effects of shear on the total production and the volumetric productivity of anthocyanin in the bio-reactor were also similar (data not shown). The pigment production and pro- 

Such information about shear effects in plant cell suspension cultures as given above is useful for bioreactor design and operation as well as the optimization of bioreactor environments for plant cell cultures. It may also be beneficial to bioreactor scale-up and high-density cultivation of plant cells for production of useful plant-specific chemicals (pharmaceuticals). In addition, because different cell suspensions can show different degrees of cell sensitivity to shear stress, and shear affects culture viability, cell lysis, and even metabolite secretion, as demonstrated in various cases like cell cultures of tobacco, Catharanthus roseus and Perilla frutescens [17, 54, 61], detailed studies are required for individual cases. 

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