Continuous cultivation of micro-organisms: A new approach and possibilities for its use

When trying to turn a batch fermentation process into a continuous process, many important factors must be repected. A new approach is presented by means of which it is possible to reproduce in a continuous system those changes (both inside the cells and in the environment) which are functions of elapsed time (lag‐type changes, sudden changes occurring at a constant growth rate of the micro‐organisms, etc.). Special attention is paid to lag‐type changes. In the hitherto described apparatuses for continuous cultivation it was difficult to follow changes which are functions of time. The use of a multi‐stage apparatus is therefore suggested, and a method of cultivation, which through adjusting retention times in individual cultivation vessels allows a detailed study of such changes, is proposed. Basic equations concerning the growth of microorganisms in the described apparatus are derived and some examples of the possible practical use of the new approach are presented.