유해조류 Microcystis aeruginosa에 대한 혼합영양 편모충 Poterioochromonas malhamensis의 성장과 섭식

To understand the ecological characteristics as herbivores of the mixotrophic chrysomonads, which are capable of both photosynthesis and phagotrophy in aquatic system, the grazing activity and growth rates of the mixotrophic chrysomonad, Poterioochromonas malhamensis feeding on the cyanobacterium Microcystis aeruginosa were investigated under different temperatures To gain more insight in to the field conditions, we conducted grazing experiments with P. malhamensis and colony forming strain of M. aeruginosa(NIER-10010). The isolated flagellate preferred a similar range of water temperature degree as natural condition during the cyanobacterial bloom. Growth rates of the flagellate were highest 1.91 d-1 in 25°C. Interestingly, P. malhamensis effectively grazed on M. aeruginosa with two size fractions(smaller and larger than 30 μm) regardless of size. These results may facilitate a better understanding of the ecological role of Poterioochromonas malhamensis in particular, as a grazer of cyanobacteria in eutrophic freshwater ecosystem.