title: A quantitative analysis of shear effects on cell suspension and cell culture of perilla frutescens in bioreactors.
abstract: The short-time effects of shear on suspended cells of Perilla frutescens were quantitatively analyzed by exposing the cells to a well-defined flow field in a rotating drum reactor. It was found that both shear rate and shearing time significantly affected cell viability. The quantitative effects of shear on cell growth and the production of anthocyanin, a secondary metabolite, by the cell cultures were further investigated in a series of batch cultivations using a 5-L plant cell bioreactor with a marine impeller. The results indicated that there was an optimum 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 values of the following parameters: the specific growth rate, the maximum cell concentration, the (specific) production and productivity of anthocyanin, and the cell and anthocyanin yields.
authors.affiliation: International Center of Cooperative Research in Biotechnology, Faculty of Engineering, Osaka University, 2-1 Yamada-oka, Suita-shi, Osaka 565, Japan.
authors.forename: J J
authors.initials: JJ
authors.lastname: Zhong
authors.forename: K
authors.initials: K
authors.lastname: Fujiyama
authors.forename: T
authors.initials: T
authors.lastname: Seki
authors.forename: T
authors.initials: T
authors.lastname: Yoshida