In shake flask and Bioreactor cultures by methanol utilizing bacteria Rubrobacter motiliticus nov var. gelatinoliquificicans -: Cultivation conditions

The Vitamin B, production using a newly isolated strain Rubrobacter motiliticus nov. var. gelatinoliquificicans was investigated. This strain can grow in minimal medium supplemented by methanol as sole carbon source. In the preliminary experiments for the production of Vitamin B, in shake flasks, the production of vitamin reached about 9.5 mg/l after 44 h. During that,time, the cell growth reached its maximal value of about 0.46 g/l. On transferring the process to well aerated stirred tank bioreactor, the vitamin production increased to 13.6 mg/l after 46 h with almost the cell mass obtained in shake flask. Further significant improvement in the production process reaching about 22.5 mg/l of vitamin B,2 was achieved upon cell cultivation in bioreactor with controlled pH at 7.2. However, the transfer of process from shake flask to bioreactor level of controlled pH not only resulted in an increase in volumetric production but also the specific vitamin production was increased from 23.8 up to 124.11 mg/g. On the other hand, after the vitamin production phase, significant degradation in vitamin was observed in all cultures under study. The highest rate of vitamin degradation was observed in bioreactor cultures was almost 4-5 folds higher than the rate obtained in shake flask.