Some experiments and analysis of a predator‐prey model: Interaction between Colpidium campylum and Alcaligenes faecalis in continuous and mixed culture

Abstract
Following previous work in which a mass and monoxenous culture of Vorticella microstoma had been successfully established (Water Res., 7, 615 lpar;1973) another species of Ciliata, Colpidium campylum was subjected to continuous cultivation using Alcaligenes faecalis as the sole bacterial food and asparagine as the limiting substrate. This work was primarily undertaken to reveal the interaction and biological oscillation between these two types of organisms which simulate theecological behavior of activated sludge.The fact that the bacteria tended to flocculate and/ or deflocculate depending on the protozoan populastion density was incorporated into the rate equations to account for the oscillation in individual population density of the predator‐prey system The mathematical approach presented earlier by canal and other workers forbiological oscillation used a homogeneously of the bacterial food wasoverelooked in the earlier publication.