Paramecium - Deutsche Gesellschaft für Protozoologie / German ...

Changes in the three-dimensional structure of a multispecies
bacterial biofilm due to grazing of Chilodonella uncinata
and Spumella sp.
Anne Böhme, Ute Risse-Buhl, Kirsten Küsel
Limnology Research Group, FSU Jena
Protozoa seem to play a major role in structuring biofilm morphology
due to grazing activity and motility. Vagile filter feeding protozoa decrease
the biofilm thickness and stimulate the formation of microcolonies,
which are known as bacterial defense strategies against grazing.
In the present study the impact of two biofilm associated species
on the three-dimensional structure of a multispecies bacterial biofilm
was investigated in a continuous laminar flow system. The gulper
feeder Chilodonella uncinata (Phyllopharyngia, Ciliophora) growing
with the filter feeder Spumella sp. (Crysophyceae, Chrysophyta)
caused an increase of biofilm porosity of 197 %, a biofilm volume
loss of 68 % and a biofilm surface area loss of 63 %. In contrast, protozoa
increased the ratio of biofilm surface area to volume (bsa/v) by
about 26 %. The impacts were even higher with the flagellate alone.
The higher bsa/v and porosity might improve exchange of nutrients
and gases between the biofilm and its surrounding fluid. Additionally,
a three-fold higher formation of bacterial microcolonies was observed
in the presence of the vagile Chilodonella uncinata and the sessile
Spumella sp., but not with the sessile Spumella sp. alone. We suggest
that microcolony formation was caused by the vagility of Chilodonella
uncinata.
anne.boehme@uni-jena.de
ute.risse-buhl@uni-jena.de
kirsten.kuesel@uni-jen.de
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