“…The continuous in vitro mmen T h e theory of continuous culture, which mas formalized by Monod (1950) and Novick & Szilard (1950), is based on the fact that only one component in the substrate will be limiting microbial growth, and that culture density (the number of organisms present) is controlled by this component. T h e rate of microbial growth in the culture is dependent only on the rate of flow of substrate and may be controlled, within limits, by adjusting the rate of dilution.…”