Autori: Dan Cascaval, Anca-Irina Galaction, Elena Folescu, Marius Turnea

Editorial: Biochemical Engineering Journal, 31, p.56-66, 2006.

Rezumat:

The efficiency of oxygen transfer into the fermentation broths could be enhanced by adding in broths oxigen-vectors, such as hydrocarbons or fluorocarbons, without increasing the energy consumption for mixing or aeration. The experimental results obtained for simulated, P. shermanii and S. cerevisiae broths indicated the considerable increase of kLa and (kLa)V /(kLa)0 by adding n-dodecane, but the magnitude of this effect must be correlated with broths and biomass characteristics, especially with the cells affinity for oxygen-vector droplets. Thus, due to the higher affinity of yeasts cells for hydrocarbon droplets, the increase of oxygen mass transfer rate was lower than that recorded for simulated or bacterial broths.
By means of the experimental data, some mathematical correlations describing the influences of the main parameters (apparent viscosity, concentration of biomass, specific power input, superficial air velocity) on kLa in presence of n-dodecane have been proposed for each considered fermentation systems. These equations offer a good agreement with the experiment, the average deviations being between 9.6% and 10.8%.

Cuvinte cheie: Biochemical Engineering, Biotechnology, Bioreactors