Aeration, fermentators

Moilanen et al [59] did use CFX to simulate two-phase aerated fermenters. A MRRF technique was employed to describe the impeller motion. The results obtained using two different turbulence closures were compared with experimental and visual observations. The two turbulence models tested were the standard k-e and the SST models. R was stated that the k-e model did behave unphysically in the bulk regions of the vessel by generating unreasonable turbulence properties. The SST model gave more reasonable results. 

Moilanen P, Laakonen M, Aittamaa J (2006) Modeling Aerated Fermenters with Computational Fluid Dynamics. Ind Eng Chem Res 45 8656-8663... 

In the laboratory a fungus can be grown on surface or still culture, in shake culture or in stirred and aerated fermentations. The extent of aeration differs between these and it affects not only the rate at which a fungus grows but it can also determine the metabolites that are produced. 

Even for the simple stirred, aerated fermenter, there is no one single solution for the scale-up of aeration-agitation which can be applied with high probability of success for all fermentation processes. Scale-up methods based on aeration efficiency (kio) or power consumption/unit volume have become the standard practice in the fermentation field. 

Charles, M., Oxygen Transfer and Mixing Characteristics ofthe Deep-Jet-Aeration Fermenter (personal correspondence). 

Soybean oil was used as an antifoam agent in aerated fermentations such as productions of penicillin, streptomycin, and tetracycline. It also markedly increases the yield of antibiotics, presumably by providing important nutrients (Smith Thompson, 1989). Soybean oil also was observed to delay the onset of blooms on fruit trees, reducing susceptibility to frost damage. 

One major product of this application of industrial fermentation is baker s yeast biomass. Baker s yeast is required for making bread, bakery products, beer, wine, ethanol, microbial media, vitamins, animal feed, and biochemicals for research. 5feast is produced in lai e aerated fermenters of up to 200,000 liters. Molasses is used as a nutrient source for the... 

Uses Antifoam for aerated fermentation of glutamic acid, yeast, antibiotics, waste and sewage treatment of pulp/paper, fertilizers, aq. and emulsion paints, desulfurization processes... 

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