Amoebas with theca

Amoebas with theca

They are amoebas that have a protective shell called theca, which can be secreted by itself or be formed by amoeba particles removed from the medium, calcareous, siliceous or organic. The thecamoebians are able to compete with other microorganisms only when the food is plentiful (high F / M ), as in the beginning of the operation of an activated sludge system. In older sludge thecamoebians indicate a nitrified wastewater with low ammonia concentration.