Workpackage 4: The effect of microbial stability on the genotypic diversity of the cultured rotifers will be studied in monoxenic and axenic cultures using a selected number of bacteria based on previous work.

It has already been proven that some bacteria have a beneficial effect on rotifers (Gatesoupe, 1991; Rombaut et al, 1999). In this study, different ad random mixtures of clones will be cultured monoxenically starting from disinfected parthenogenetic eggs (Dhert, 1996). The effect of a single bacterial strain will be assessed. Some bacteria may have a positive effect on one clone and a negative on another. Bacteria that produce digestive enzymes may be beneficial to a clone that is missing the genetic information to produce this enzyme.
After the first set of experiments, several xenic cultures will be run. These cultures will be repeated in time. Bacteria producing digestive enzymes or other products may steer the genetic drift.