peter bossier wrote:
>> hallo everybody,
>> During the last two years i've been working with a Comamonas
> testosteroni strain which makes on plates two different types of
> colonies, namely one type is producing EPS and the other type is not
> producing EPS. I've called cells producing the latter type of colonies
> NMCF-cells (non-mucoid colony forming); the other are MCF-cells. ON
> plate cells are typically switching between the two forms, making
> sectored colonies.
> More interestingly, a population of cells containing the two different
> forms will shift towards dominance by NMCF-cells every time stress is
> being applied (e.g. hydrogen peroxide, oxidative radicals, temperature
> rise, visible light, SDS, starvation, probably others ...).
> NMCF-cells are also more hydrophobic than MCF-cells since they stick
> better to polystyrene and to gas bubbles.
> Based on these findings i've been constructing a model which allocates a
> ecophysiological role for both type of cells. I would like to hear from
> you if that model make sense?
> I consider the MCF-cells (which are producing EPS) as the biofilm
> growers. NMCF-cells could hang around in a biofilm, probably more
> concentrated at the "biofilm surface" which is more exposed to
> environmental stress. NMCF-cells could detach from the biofilm by
> sticking to gas bubbles (produced by denitrification or photosynthesis)
> and as such function as disseminators in a ecosystem. NMCF-cells could
> adhere then to a fresh substratum and switch back to the EPS producing
> What do you think?
> peter bossier
> Peter Bossier
> Lab. Mikrobiele Ecologie, Coupure L653, 9000 GENT,Belgium
> Tel: 32 9 2645976 Fax: 32 9 2646248
> e-mail: peter.bossier at rug.ac.be
Hypothesis might have relevance. How will you test?