Simultaneous production and decomposition of different rifamycins during Amycolatopsis mediterranei growth in shake flask and in stirred tank bioreactor

The present work deals with the kinetics of rifamycins production and degradation by Amycolatopsis mediterranei in submerged culture using industrial medium. Cultivations were conducted in shake flasks and stirred tank bioreactor to evaluate the influence of transfer of process to higher scale on overall process kinetics and to obtain better understanding for the kinetics of rifamycins production and degradation. Both rifamycins B and SV increased with time in both shake flasks and bioreactor cultures and reaching their maximal value after about 200 h. The maximal production of rifamycins B and SV was about 4832 mg l and 3967 mg l, respectively, in bioreactor cultures. These values were about 75% higher than those obtained in the corresponding batch culture in shake flasks under the same cultivation conditions. On the other hand, rifamycin O is produced as an intermediate product reaching its maximal value after about 100 h and decomposed again with time and totally disappeared at the end of cultivation time.