48 Fermentation and Biochemical Engineering Handbook 目 dry weight四 metabolite口 dry weight■ metabolite productivity ity for cell mass and anthraquinones in systems.(1)Shake Fla Flat Blade Turbine. ()Perfolated Disk (4 Draft Tube Bioreactor with Turbine, (5)Air-lift Bioreactor. Air Driven Bioreactors. The simplest design is the air-driven bioreactor equipped with sparger at the bottom of the vessel. It is widely used for plant cell, tissue, and organ cultures. In cases wherethe cells grow rapidly and the cell mass occupies 40-60% of the reactor volume, the flow charac teristics become non Newtonian and the culture medium can no longer be agitated by simple aeration Rotating Drum bioreactor The rotating drum bioreactor(Fig. 21) turns on rollers and the oxygen supply mechanism is entirely different from either the mechanically agitated or the air-lift bioreactor. Tanaka et al (1983), 4) reported that the oxygen transfer coefficient is affected by a change of airflow rate under all rotational speeds(Fig. 22). This character istic is suitable not only for the growth of plant cell, tissue, and organs but also for the production of metabolites under high viscosity and high density cultures. It is superior to the cultures using either mechanically agitated air-lift bioreactors since the cultures are supplied ample oxygen and are only used for a pilot scale experiment (Tanaka 1987). ye was constructed and weakly stressed. Recently a I kl bioreactor of this typ48 Fermentation and Biochemical Engineering Handbook 10 I 0.5 wrn 100 rprn I 101 0.5 wm 100 rprn I u4 75 I 0.33 vvm 350 rprn dry weight metabolite JJ dry weight metabolite yield productivity Figure 19. Comparison of yield and productivity for cell mass and anthraquinones in various bioreactor systems. (1) Shake Flask. (2) Flat Blade Turbine. (3) Perfolated Disk Impeller. (4) Draft Tube Bioreactor with Kaplan Turbine. (5) Air-lift Bioreactor. Air Driven Bioreactors. The simplest design is the air-driven bioreactor equipped with sparger at the bottom ofthe vessel. It is widely used for plant cell, tissue, and organ cultures. In cases where the cells grow rapidly and the cell mass occupies 40-60% of the reactor volume, the flow charac￾teristics become non-Newtonian and the culture medium can no longer be agitated by simple aeration, Rotating Drum Bioreactor. The rotating drum bioreactor (Fig. 21) turns on rollers and the oxygen supply mechanism is entirely different from either the mechanically agitated or the air-lift bioreactor. Tanaka et al., ( 1983),[14] reported that the oxygen transfer coefficient is affected by a change of airflow rate under all rotational speeds (Fig. 22). This character￾istic is suitable not only for thegrowth ofplant cell, tissue, and organs but also for the production of metabolites under high viscosity and high density cultures. It is superior to the cultures using either mechanically agitated or air-lift bioreactors since the cultures are supplied ample oxygen and are only weakly stressed. Recently a 1 kl bioreactor of this type was constructed and used for a pilot scale experiment (Tanaka 1987).[15]