A QUANTITATIVE-ANALYSIS OF SHEAR EFFECTS ON CELL-SUSPENSION AND CELL-CULTURE OF PERILLA-FRUTESCENS IN BIOREACTORS

The short-time effects of shear on suspended cells of Perilla frutesce ns were quantitatively analyzed by exposing the cells to a well-define d flow field in a rotating drum reactor. It was found that both shear rate and shearing time significantly affected cell viability. The quan titative effects of shear on cell growth and the production of anthocy anin, a secondary metabolite, by the cell cultures were further invest igated in a series of batch cultivations using a 5-L plant cell biorea ctor with a marine impeller. The results indicated that there was an o ptimum range of shear rate; i.e., an average shear rate of 20 to 30 s( -1) or an impeller tip speed of 5 to 8 dm/s, which maximized all the v alues of the following parameters: the specific growth rate, the maxim um cell concentration, the (specific) production and productivity of a nthocyanin, and the cell and anthocyanin yields. (C) 1994 John Wiley a nd Sons, Inc.