Precultivation technique for studies of microorganisms exhibiting overflowmetabolism

A precultivation technique for microorganisms exhibiting overflow metabolis m is presented. It is based on a low initial medium volume in the fermenter . The medium feed contains all the nutrients, but is diluted with respect t o sugar, the concentration of which determines the biomass concentration at the end of the preculture. By this method, effects of varying activity of the inocula from shake flask cultures are minimised and the metabolic state , i.e. oxido-reductive, oxidative growth on sugar plus overflow metabolite or oxidative growth on sugar alone, can be controlled at the start of the m ain fermentation.