Continuous production of antibiotics in an airlift fermenter utilizing a transverse magnetic field

In this study, a series of experiments was conduct-ed to demonstrate the fe asibility of continuous production of penicillin antibiotic using a three-p hase magneto airlift fermenter with immobilized Penicillium chrysogenum. Th e fermentation processes were carried out in a 2.4-L external loop airlift utilizing a transverse magnetic field. It was found that the application of the magnetic field to a bed of ferromagnetic beads affects both the hydrod ynamics of the reactor and the rate of the bioconversion process occurring inside it. One hundred hours after startup, the maximum penicillin concentr ation increased 48% as the magnetic field intensity ir;creased from 0 to 35 mT, owing to the increased residence time of the substrate in the riser an d the positive effect of the magnetic field on the effective fluid-solid in terfacial area. In addition, the detached biomass concentration in the liqu id phase was found to be only 5% of the immobilized biomass, owing to low s hear levels and the absence of friction among the solid-phase particles.