Abstract
By using urethane foams as immobilizing carriers for Penicillium chrysogenum, the effect of apparent volumetric mass transfer coefficient of oxygen kLa on penicillin production in a fluidized-bed bioreactor (FBR) was investigated. The kLa value was measured by varying the amount of urethane foam carriers added as well as aeration rate, suspended cell mass concentration and antifoam reagent concentration in a model cultivation system. High production of penicillin by batch operation was obtained in the operational region where the volumetric ratio of carriers in the working volume of FBR was 0.3 to 0.4 and gas superficial velocity was 0.03 to 0.05 m·s–1. Under these fluidizing operational conditions, a repeated batch operation was performed. The adhered cells in the carriers could be used repeatedly for semicontinuous production of penicillin, and a penicillin yield of about twice the quantity of lactose utilized could be obtained.
