Effect of Microcystis Aeruginosa (Cyanobacteria) Abundance on the Growth and Ingestion of Poterioochromonas sp. (Chrysophyceae)

Poterioochromonas sp., isolated from the mass culture of Microcystis, was a mixotrophic flagellate. It could grow not only in inorganic medium, but also by ingestion and digestion of Microcystis. In this study, the growth and ingestion characteristics of Poterioochromonas sp. was investigated with modified Monod model and Michaelis-Menten model, respectively. The results showed that, the relationship between flagellate growth rate (initial concentration ap 10⁵ cellsldrmL^-1) and prey density (Microcystis aeruginosa FACHB469, *10⁶ cellsldrmL^-1) was denoted by the fomula: growth rate (mu, h^-1)= 0.054* [(x+1.46)/(4.24 +x+1.46)] (r² = 0.919). And the model for ingestion rate was expressed by the equation: Ingestion rate (I, cellsldrflag^-1 h^-1) = 3.3*[x/ (3.76 +x)] (r² = 0.946).