The inhibition of low light intensity on the growth of Microcystis aeruginosa in raw water

The growth trend of Microcystis aeruginosa in raw water was studied under various conditions of illumination. Using sterile raw water as culture medium at cultured period of 13d, 23°C, and when illumination ≤500 1x, the growth of Microcystis aeruginosa was inhibited obviously with the specific growth rate (°) of negative number. At 28°C, if illuminating ≤200 1x, the maximum algal existent amount was reduced above 70% compared with at 4300 1x. Using unsterile raw water as culture medium, at 23°C, the Microcystis aeruginosa disappeared gradually, this was related with occurrence of great amount of zooplankton.