Abstract
Several combinations of backmix, tubular‐loop, and plug‐flow fermentors with and without culture recycle were studied by computer simulations. The steady‐state concentrations of cell mass in a continuous culture were calculated as a function of dilution rate using Monod growth kinetics. It was found theoretically and verified for one case experimentally that the maximum dilution rate, over which microbial cells were washed out from the fermentor, could be elevated well beyond the maximum specific growth rate if a particular fermentor combination was used. A combination of two backmix fermentors has been analyzed previously by Sinclair and Brown. Application of this type of fermentor combination as a seed tank for performing continuous culture of microbes in a plug‐flow reactor was shown with special reference to fermentation production using the kinetics proposed by Luedeking and Piret, van Dedem and Moo‐Young, and Brown and Vass.