Sterilization of bioreactor media on the basis of computer calculated thermal input designated asF 0

Abstract

Industrial fermentation media are normally sterilized with steam to destroy the indigenous microbial population prior to inoculation with a specific microorganism. Because biological validation of each sterilization cycle is impractical, an ‘overkill’ approach is commonly employed on the basis that alteration of heat-sensitive nutrients is less detrimental than survival of indigenous microbes. However, the heat destruction of microbes is known to be a probability function amenable to calculation. A computer has been programmed to calculate the on-line heat input asF₀ values during sterilization of media in stirred bioreactors. The accumulation ofF₀ values is then announced verbally to bioreactor operators by a communications controller with voice synthesizer.