effect of aeration rate on biosurfactin production in a miniaturized bioreactor

recently, the production of biosurfactants in bioreactors and their use in various pharmaceutical,chemical and food industries have been developed. optimum production is directly related to the physicochemicalcondition of culture medium (such as ph and temperature) and engineering parameters of bioreactors (such asaeration rate, volume of operation and the amount of energy input). understanding the gas transfer in shakenbioreactors equipped with a sterile closure is advantageous to avoid oxygen limitation or carbon dioxideinhibition of a microbial culture. in this study, the effect of aeration rates (due to using different designclosures) on the amount of biosurfactin production by bacillus subtilis atcc 6633 in a ventilation flask as aminiaturized bioreactor was investigated. the highest biosurfactin concentration (0.0485 g/l/h) was obtainedin the optimum conditions in which the amount of filling volume and shaking frequency were 15 ml and 300rpm, respectively. the specific aeration rate (qin) and maximum oxygen transfer rate (otrmax), were calculated1.88 vvm and 0.01 mol/l/h, respectively. the results showed the significant biosurfactin productivity increaseunder non-oxygen limiting condition.