Feeding of Vampirellid Amoeba (Leptophryidae) on Cyanobacteria

Harmful cyanobacterial blooms cause serious environmental, social and economic damage, including the poisoning of humans and animals. The mitigation of harmful blooms is possible through biological approaches based on trophic interactions between phagotrophic protists and cyanobacteria, i.e., through “top-down control” by predatory microbial eukaryotes. We have conducted experimental studies on the ability of predatory vampyrellid amoebae (Vampyrellida) to feed on the toxic and nontoxic cyanobacteria Microcystis aeruginosa and Aphanizomenon sp. It has been shown that the vampyrellids Vernalophrys algivore and Kinopus chromellivorus can actively consume cells of the nontoxic M. aeruginosa strain FACHB928, increasing in abundance, but are unable to feed on the toxic M. aeruginosa strain FACHB905 and Aphanizomenon sp. strain FACHB1399, which form long filamentous trichomes. The results obtained may be useful for the development of biological methods to regulate and control harmful cyanobacterial blooms affecting the ecological balance in aquatic ecosystems and water quality.