| Amoeba are
essentially everywhere and can be isolated from almost any kind of
sample; soil, freshwater or salt water. Most methods for
isolating amoeba are based on the "walk out" method in
which a mono-layer of bacteria (usually E.coli) is deposited
on an agar plate, and any amoeba present inoculum crawl as they
consume the bacteria, to produce characteristic haloes of
growth. Of course, just as 95% of bacteria cannot be easily
cultured, by simple inoculative methods, so we can be certain that
a proportion of the amoeba initially present cannot be cultured by
this simple method and are rapidly overgrown by the usual amoebal
"weeds"! This makes it very important to consider
what type of organism we would wish to culture.
The source of sample is a very important
influence over which type of amoeba predominates in the
culture. For example, if one is interested in obtaining Naegleria,
then the best source would be freshwater. If Acanthamoeba are desired then soil is the best bet especially if
the soil is rich in organic content. Flattened or flabellate
amoeba (Vannella, Platyamoeba etc) are most likely to be
found in marine samples
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