Oxygen transfer rate bioreactors

A 20 m3 working volume of a bioreactor is used for producting penicillin. What would be the sugar concentration (S0) you choose if oxygen transfer rate is not the limiting reactant Given data ... 

Foam in the bioreactor is troublesome it can reduce the oxygen transfer rate (OTR). Antifoam is use to prevent foam formation. However, excess antifoam may cause growth inhibition in the course of fermentation. The simplest device is known as a foam breaker, which is mounted on the stirrer shaft located on the surface of liquid. It is a flat blade. 

A 20 m3 working volume of bioreactor is used for production of penicillin. What is the initial substrate concentration, S0, that you choose when there is a limitation in sufficient oxygen transfer rate and there are no limiting reactants ... 

If you aerate a bioreactor, power consumption is much less than a non-aerated bioreactor. Oxygen transfer rate, OTR 6 X 10 3 kgm-3 Oxygen uptake rate, OUR 0.65 mmol 02 kg 1 cell Specific growth rate, umax 0.5 h 1... 

Pressure Most bioreactors are operated at normal atmospheric pressure however, in some cases with high oxygen requirements, such as high-density cultivation, a bioreactor must be pressurized in order to enhance the oxygen transfer rate. In such cases, the control of vessel pressure is essential. 

Cornel, P., Wagner, M. and Krause, S. (2003) Investigation of oxygen transfer rates in full scale membrane bioreactors. Water Science Technology, 47 (11), 313-319. 

Since the biomass production is an aerobic process and air should be supplied to cultures, efforts are being made to develop bioreactors having higher oxygen transfer rates and lower power requirements. 

A widely used parameter in the quantitative analysis of the oxygen transfer rate in wastewater treatment bioreactors is the dimensionless factor, a, defined by the following equation ... 

Johnson M, Andre G, Chavarie C Archambault J (1990) Oxygen transfer rates in a mammalian cell culture bioreactor equipped with a cell-lift impeller. Biotechnology and Bioengineering 35 43-49. 

The rate of this reaction is independent of the concentration of sodium sulfite (within the range of 0.04 to 1 N) and is also much faster than the oxygen transfer rate. Therefore, the rate of oxidation is controlled by the rate of mass transfer alone. The sodium sulfite solution, however, has quite different physical and chemical properties. This technique is helpful though in comparing the performance of bioreactors and studying the effect of scale-up. 

Bioreactors that use enzymes but not microbial cells could be regarded as fer-mentors in the broadest sense. Although their modes of operation are similar to those of microbial fermentors, fed-batch operation is not practiced for enzyme reactors, because problems such as excessive cell growth rates and resultant high oxygen transfer rates do not exist with enzyme reactors. The basic equations for batch and continuous reactors for enzyme reactions can be derived by combining material balance relationships and the Michaelis-Menten equation for enzyme reactions. 

The oxygen transfer rate per unit volume of the bioreactor, Qq2, can then be expressed as... 

Garcia-Ochoa, R, and Gomez, E. (2009), Bioreactor scale-up and oxygen transfer rate in microbial processes An overview, Biotechnology Advances, 27(2) 153-176. 

The spherical type bubble column bioreactor (Figure 2.8) is another modified airlift reactor with spherical shape instead of cylindrical. Ihrough the addition of small amounts of agar to the culture medium, low shear stress is achieved as well as high oxygen transfer rates. As a result, 5.6 g.L of BC were produced after 72 hours of cultivation [54,55]. 

The oxygen transfer rate (OTR) from air to culture is a critical parameter in these microbial cultivation processes, and the effects of different conditions of agitation and aeration on the production of decalactones were investigated with Y. lipolytica [128]. OTR depends on the fluid s physical properties, temperature, pressure, solution composition, agitation, oxygen superficial gas velocity, and the configuration of the reactor [129]. OTR in a system is a function of the volumetric mass transfer coefficient (kid) and the oxygen solubility in the medium. For a specific bioreactor and medium, it is possible to increase and, consequently,... 

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