Bioprocess agitation

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. 

Power Consumption Power consumption sometimes becomes important in industrial bioprocesses, because the power used for aeration and agitation can be highly expensive. The cost of power consumption occupies approximately 15-20% of total production cost in aerobic fermentation processes. 

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. 

Mechanically agitated and pneumatically agitated fermenters are commonly used in the bioprocessing industries. Figs. 1-5 and Table 1 show the schematics of these bioreactors and their specific usage based on fermentation criteria outlined by Storhas. ... 

Ayyappan B., Kaiaichelvi P., Muhugesan T., Suspension of solid particles in turbine agitated contactors. Bioprocess Engng. 15 (1996), p. 205-208... 

The continuous generation of heat by microbial cultures can also be used as a basis for an on-line monitoring of the microbial activity and metaboUsm. If the temperature increase in the cooling water, its flow rate, and the other relevant energy exchange terms such as agitation and evaporation rates are measured systematically, the heat dissipation rate of the cellular culture can quantitatively be monitored on-line in industrial fermenters. The information contained in this signal can be used to optimize the bioprocess and for on-line process control. 

Aravinth S, Gangadhar Rao P, Murugesan T. (1996) Critical impeller speed for solid suspension in turbine agitated contactors. Bioprocess Eng., 14 97-99. 

Cherry RS, Papoutsakis ET. (1986) Hydrodynamic effects on cells in agitated tissue culture reactors. Bioprocess. Eng., 1 29 1. 

The other important adsorption unit operation used for bioprocesses is the agitated bed adsorber. In this process, the liquid (e.g., cell culture broth) is passed through a series of agitated columns containing adsorbent. The simple mathematical equation for the n — th column in the series is given below. 

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