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The World of Protozoa, Rotifera, Nematoda and Oligochaeta

Ref ID : 7349

Christa H. Ratsak, Bob W. Kooi, and Bas Kooijman; Modeling the Individual Growth of Tetrahymena Sp. and its Population Consequences. J.Eukaryot.Microbiol. 42(3):268-276, 1995

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Three types of mathematical growth models are presented to describe the individual growth of the ciliate Tetrahymena sp. feeding on the bacterium Pseudomonas fluorescens. Both organisms were isolated from a domestic waste-water treatment plant. Growth of individual ciliates and the consequences for the whole population are considered. Experimental data, obtained by following the individual ciliate during its lifespan from cell division to cell division, are used for parameter estimations. Differences between growth models for individuals turn out to have little effect on the specific population growth rate and the mean cell volume. In case of exponential growth of individuals the unstructured and structured population models are equivalent, even in time-variant environments. This knowledge can be applied in the stability analysis of food chains or forced systems. The results obtained facilitates quantification of protozoa biomass as a function of bacterial biomass in chemostats. More specifically, it highlights the dynamic behaviour of bacteria and protozoa in waste-water treatment plants.