In this paper, a optimum fermentation condition for the production of aminoglucoside using genetically engineered microbial cell. During the fermentation, MgSO₄ was used to increase the activity and production yield of antimicrobial compound by escalating the separation effect of aminoglucoside. In the flask culture, antimicrobial activity of the culture was found to be maximum 48 hours after the inoculation at the concentration of 150 mM MgSO₄. On the other hand, to get the maximum activity in the bioreactor, 0.5 M of was added 48 hours after the inoculation.