Small-scale liquid mixing in a bioreactor column with xanthan-gum simulated filamentous media

Using the heat pulse technique, the local mean flow liquid velocity and the mixing conditions for two-phase flow in the riser of an airlift bioreactor have been measured and analysed. Xanthan-gum solutions were used as the ph ysical model to some filamentous broths reported in the literature. A two-f old decrease of liquid velocity and diffusional mixing regime are predicted for the course of a fermentation process proceeding in a non-Newtonian bio mass growth circulation system.