Degradation of Cyanobacteria, Microcystis by Microflagellate, Monas guttula

Characteristics of degradation of cyanobacteria, Microcystis aeruginosa, by Masugophota-Monas guttula were examined. Monoxenic M.guttula was isolated from sewage in the biological oxidation facility equipped in Kasumigaura Water Works. M.guttula was able to efficiently degrade viable cells of M.aeruginosain a short time. The removal of cells by M.guttula was 90% at 48 hr cultivation. The specific growth rate (µ) and generation time (t_g) of M.guftuia were 4. l day⁻¹ and 4.0 hr, respectively. The maximum specific growth rate(µ_max) and saturation coefficient (Ks) of the microbe were 4.4day⁻¹ and 2.4 mg/l with Lineweaver-Burke equation. Effects of physical factors on the removal of M.aeruginosa by M.guttula, pH and temperature were examined. Greater than 80% of removal was obtained at pH 7.0. At 30°C, the maximum removal was over 90% as compared with 20% at 5°C. It was clarified that M.guttula could effectively utilize M.aeruginosa as food, and it was found that pH and temperature were important physical factors to remove the Cyanobacterium M. aeruginosaby microflagellate M.guttula.