Experimental and modeling studies of a four-trophic level predator-prey system

Abstract

Experimental studies of a microbial food chain involving organic carbon substrates,Enterobacter aerogenes, and ciliate protozoansParamecium primaurelia andDldinium nasutum were conducted in stirred, aerated batch cultures. Quantitative measurements were made of organic carbon levels and of cell numbers, mean cell volumes, and total biovolumes for all three microbial populations. A mathematical model based on Monod kinetics was developed to describe this four-trophic level predator-prey system. The model was formulated in terms of biovolume, which is the product of cell numbers and mean cell size, and includes terms for bio-volume decay. Batch culture data were used to derive parameter values, and model simulations were compared to experimental results. Despite the significance ofParamecium-Didinium studies in ecological literature, the entire food chain has not been previously studied or modeled.

A modelling approach to the interplay of carbohydrates, bacteria and non-pigmented flagellates in a controlled ecosystem experiment with Skeletonema costatum

“…Jost et al (1973) developed 2 models for grazing of bacteria by ciliates based on Monod-type kinetics, and reported these to fit very well with data obtained from culture experiments (Proper and Garver, 1966;Hamilton and Preslan, 1970;Tsuchiya et al, 1972). Later developments in predator-prey systems modelling seem to confirm this statement (Dubois, 1979;Graham and Canale, 1982). FencheI (1982b) found that exponential growth rates as function of bacterial density fitted to a Michaelis-Menten form equation in growth experiments with 5 different species of bacteria-feeding flagellates.…”

Determining Microbial Kinetic Parameters Using Nonlinear Regression Analysis

“…Partly for this reason, microbiologists (Powell, 1967;Robinson and Tiedje, 1983;Corman and Pave, 1983) and mathematicians (Holmberg, 1982) have investigated the general applicability of this nonlinear model for the estimation of Monod growth parameters. In some cases (Knowles et at., 1965;Graham and Canale, 1982) the integrated Monod equation has been used with little regard to its limitations, which can be severe.…”

Bacterial biomass production and ammonium regeneration in Mediterranean sea water supplemented with amino acids. 2. Nitrogen flux through heterotrophic microplankton food chain

“…While numerous papers deal with nitrogen behaviour through bacterial communities by considering C/N ratios and NH,+ fluxes (Amano et al 1982, Graham & Canale 1982, Laake et al 1983, others deal more precisely with interactions between bacteria and microflagellates with classical predator-prey considerations (Fenchel 1982, Graham & Canale 1982, Laake et al 1983; only a few studies deal with the influence of Protozoa on microbial activity or the qualitative composition on bacteria or vice versa (Gude 1979, Sherr et al 1982, Sherr et al 1983.…”