Aeration-agitation bioreactor

Cell culture aseptic suspension culture of cells in liquid media in aerated, agitated bioreactors (60,64). The products of primary interest are high-value secondary metabolites. 

Tragardh, Ch., A Hydrodynamic Model for the Simulation of an Aerated Agitated Fed-Batch Fermentor . Proceedings of the 2nd International Conference on Bioreactor Fluid Dynamics, Cambridge, UK 117-134 (1988). 

For anthocyanin production by cell cultivation of Perilla frutescens in an agitated bioreactor, at an aeration rate of 0.1 wm using a sintered sparger, its accumulation was poor, showing almost the same result as that at 0.2 wm using a ring sparger, when the other cultivation conditions were maintained the same [23]. However, when the aeration rate was increased to 0.2 wm with the sinter-... 

Fig. 1. Different types of bioreactors for plant cell, tissue and organs. (A) mechanically-agitated bioreactors, a aeration-agitation, b rotating drum, c spin filter. (B) air-driven bioreactors, a bubble column, b draft tube, c external loop, (C) non-agitated bioreactors, a gaseous phase (mist), b oxygen permeable membrane aerator, c surface aeration, (D) light emitting draft tube...

Before any additive is to be used with a given cell type, it should first be tested to ensure that it has no detrimental effects on cell growth, metabolism, differentiation, protein expression, etc., and that it does indeed offer mechanical protection in agitated and/or aerated systems (bioreactors). 

Figure 18. Different types of bioreactors for plant cells, tissues and organs. (A) Shake Flask. (B) Aeration-Agitation. (C) Percolated Impeller. (D) Draught Tube Air-lift. (E) Draft Tube with Kaplan Turbine. -Air-liftloop. (Gj Rotating Drum. (7/1 Light Emitting Draught Tube. (I) Spin Filter. (J) Bubble Column. (K) Aeration. (L) Gaseous Phase.

Tragardh C (1988) A hydrodynamic model for the simulation of an aerated agitated fed-batch fermentation. In Bioreactor fluid dynamics. Elsevier, p 117... 

Until recently most industrial scale, and even bench scale, bioreactors of this type were agitated by a set of Rushton turbines having about one-thind the diameter of the bioreactor (43) (Fig. 3). In this system, the air enters into the lower agitator and is dispersed from the back of the impeller blades by gas-fiUed or ventilated cavities (44). The presence of these cavities causes the power drawn by the agitator, ie, the power requited to drive it through the broth, to fall and this has important consequences for the performance of the bioreactor with respect to aeration (35). k a has been related to the power per unit volume, P/ U, in W/m and to the superficial air velocity, in m/s (20), where is the air flow rate per cross-sectional area of bioreactor. This relationship in water is... 

Non-stirred, aerated vessels are used in the process for traditional products such as wine, beer and cheese production. Most of the newly found bioprocesses require microbial growth in an aerated and agitated system. The percentage distribution of aerated and stirred vessels for bioreactor applications is shown in Table 6.1. The performances of various bioreactor systems are compared in Table 6.2. Since these processes are kinetically controlled, transport phenomena are of minor importance. 

The third section deals with engineering principles of bioprocess. The chapter 8 deals with sterilization process and its engineering considerations (up stream process). The ninth chapter includes agitation and aeration in cellular growth and its impact on designing the bioreactors. The last chapter deals with brief introduction to down stream processing. 

For scale-up of inoculum conditions of hairy root cultivation, a 1-L bioreactor (working volume of 800 mL) was used. This bioreactor had a height/diameter aspect ratio of 7.14. The bubble bioreactors had no internal mechanical agitation parts. The supplied aeration rate was 0.1 wm at the bottom by sparger. Each bioreactor was inoculated with 0.2-2.0 % (w/v) g fresh weight of hairy roots and cultured for 32 d. 

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