3. Results
Free-living amoebae were present in all stages of the treatment
system throughout the study period. The highest number of amoebic
isolates was found in the aeration tank, although there was little
difference with the other stages, of 3 or 4 isolates (Fig. 1).
No seasonal distribution was observed during the year; nor was
there any significant difference in the number of isolates obtained
at the two incubation temperatures (30 and 37 C) (Fig. 2).