Abstract
Predation and degradation characteristics of cyanobacteria, Microcystis using functional micro-animals, Mastigophora Monas guttula, Rotifera Philodina erythrophthalma and Oligochaeta Aeolosoma hemprichi, which were isolated from a biofilm in a practical biological treatment facility as a preliminary treatment of source water for water supply, were examined in batch predation and degradation experiment. A small flagellate, M.guttula effectively predated on the singly dispersed viable cells of Microcystis wesenbergii with the removal ratio of 94% for 6 days. As for the predation of the colonial M.wesenbergii, A.hemprichi was found to play an important role for the effective degradation of Microcystis by M.guttula. It was also clarified that A.hemprichi could enhance the degradation of the natural colony of Microcystis obtained from eutrophicated lake water. In order to reduce effectively the colonial Microcystis, it is important to activate a food chain of sequential functional microorganisms in aquatic ecosystem.
