Increased productivity of Cyclodextrin Glucanotransferase using continuous culture

The production of Cyclodextrin glucanotransferase (CGTase) from Bacillus sp. G1 was successfully increased using continuous culture. The highest CGTase activity in batch culture was 28.1 U/ml. The study in continuous culture was focused on the effect of different time (12, 24 and 48 hours) to start pumping fresh medium at fixed dilution rate of 0.03 per hour. Results showed that the pumping time did not give significant changes in CGTase activity (25.7, 26.3 and 26.1 U/ml, respectively) and in CGTase productivity (0.77, 0.78 and 0.78 U/ml/h) respectively at steady state operation. Nevertheless, the productivity (0.77 U/ml/h) of CGTase was found to be higher than that obtained in batch culture when the time interval between batch run was taken into account. The productivity could be further increased by pumping the media earlier than 12 hours and also by increasing the dilution rate.