Production of penicillin in a fluidized-bed bioreactor using a carrier-supported mycelial growth

Abstract

A carrier-supported mycelial growth of Pencillium chrysogenum was applied to penicillin fermentation system using cells as a support material. A three-phase fluidized-bed fermentor was designed and tested for penicillin production using the bioparticles. Two modes of operation, semicontinuous and repeated fed batch, of the fermentor were tried. It was noted that the overgrowth of free mycelia and the development of fluffy loose bioparticles caused poor mixing and made the fermentor operation quite difficult. Control of the bioparticle size and the extension of production phase were therefore considered important to maintain the reactor productivity at a desired level. From the results of repeated fed-batch operation it was found that the control of bioparticle size could be successfully achieved by phosphate-limiting culture condition. Pencillin production under this condition was also observed to be maintained at a high level (about 80% of the maximum) for at least 1 month.