Allelopathic effect of Acorus calamus on Microcystis aeruginosa

Inhibitory effects of Acorus calamus on Microcystis aeruginosa were studied under coexistence conditions. Through cultured in two-cell container and excluded the influence of bacteria and nutrient, A. calamus could inhibit the growth of M. aeruginosa, which was observed by the decrease in optical density (OD680) of the culture. The intensity of allelopathy was related to the comparatively biomass of A. calamus and M. aeruginosa, for 100g of A. calamu demonstrated the strongest inhibitory effect at the original OD680 of 0.2 in the experiment. The allelochemics could be secreted from the roots of A. calamus, and A. calamus with injured roots showed no inhibitory effect. The physiological analysis of alga cell in the process showed that the existence of A. calamus lowered the content of proteins in cell, causing the antioxidative enzyme activities including SOD, MDA and CAT increase. The inhibitory effects might due to the excessive accumulation of reactive oxygen species.