ABSTRACT:
In aerobic fermentations, the supply of oxygen to the microorganism is one of the variables which will affect the yield. An aerobic fermentation can be carried out only when the oxygen, which the organism is continuously absorbing from the mash, is continuously replaced and hence the problem of aeration is of considerable importance for successful fermentation. In this study, the supply of air was initially maintained at a high level but was subsequently reduced to varying levels at different stages of the stationary phase and the results were observed and compared with control. The aeration was maintained at uniform level throughout the fermentation cycle. A reduction in the aeration level from 1.0 vvm to 0.25 vvm at all stages of the stationary phase resulted in a decrease in the antibiotic production compared to control maintained at 1.0 vvm level. On the 7th day the difference in production of Neomycin narrowed to 400 units out of 7400 units between the sparged flask aerated at 1.0 vvm and the one where aeration was reduced to 0.25 vvm after 120 hours.