Local gas hold-up in xanthan-gum-simulated actinomyces media in a stirred bioreactor

The distribution of gas hold-up in pseudoplastic xanthan-gum media, as prepared to mimic bioreactor states formed in the time-course of fermentation of Streptomyces fradiae during the antibiotic production of Tylosin, is studied. Cases of gas maldistribution at high viscosity, such as very low gas concentration near the vessel wall and relatively high gas concentration near the vessel axis, which reveal flow deficiencies, such as gas channelling and flow stagnancy, are registered and quantified.