Allelopathic Effects on Microcystis aeruginosa and Allelochemical Identification in the Cuture Solutions of Typical Artificial Floating-Bed Plants

Cyperus alternifolius ( C. alternifolius ) and Canna generalis ( C. generalis ) are widely used as artificial floating-bed (AFB) plants for water pollution control. This study evaluated the release of anti-cyanobacterial allelochemicals from both plants in AFB systems. A series of cyanobacterial assays using pure culture solutions and extracts of culture solutions of C. alternifolius and C. generalis demonstrated allelopathic growth inhibition of a cyanobacterium M. aeruginosa . After 45 days of incubation by the culture solutions, both final inhibitory rates of M. aeruginosa were more than 99.6% compared with that of the control groups. GC/MS analyses indicated the presence of a total of 15 kinds of compounds, including fatty acids and phenolic compounds, in both plants’ culture solutions, which are are anti-cyanobacterial. These findings provide a basis to apply artificial floating-bed plants for cyanobacterial inhibition using allelopathic effects.