Power Input and Oxygen Transfer in Fed-Batch Penicillin Production Process

Abstract

Fed-batch experiments in a 20 l fermentor utilizing Penicillium chrysogenum IFO 8644 were conducted using a medium containing sucrose and corn steep liquor as main components. The runs were interrupted at different stages of the process – 24, 48, 72, 96 and 120 h — and broths were transferred to an agitated vessel. Power consumption under gassed and ungassed broths and volumetric oxygen transfer coefficient, k_La, were measured for various agitation speeds and aeration rates. The rheological characteristics of each broth were also determined. Power number — modified Reynolds number plots were similar to those for other non -Newtonian fluids. Michel and Miller correlation was applied for predicting gassed power drawn for all broths. A general correlation for k_La, as a function of operating variables and apparent viscosity for broths of different cultivation ages was obtained.