Inhibitory effect of succinic acid, cinnamic acid and vanillic acid from Pontederia cordata on Microcystis aeruginosa

Abstract

Objective With succinic acid of fatty acids, cinnamic acid and vanillic acid sdanders of phenolic acids, three allelochemicals extracted from Pontederia cordata rhizomes used both alone and jointly. Method This paper is aimed at an investigation of the effects of organic acids on the growth of Microcystis aeruginosa. Result (1) The growth of M. aeruginosa could be inhibited by succinic acid, cinnamic acid and vanillic acid either solely or jointly, with 92.78% as the inhibition rate achieved with the employment of 100 mg·L−1 succinic acid and cinnamic acid for seven days; (2) when used alone, cinnamic acid demonstrates the strongest inhibition ability with succinic acid and vanillic acid following behind, yet when used jointly, the inhibition ability weakens in the following order: succinic acid + cinnamic acid ＞ cinnamic acid + vanillic acid ＞ succinic acid + cinnamic acid + vanillic acid with vanillic acid weakening the inhibition effect of succinic acid and cinnamic acid on the growth of M. aeruginosa to a certain degree; (3) when succinic acid was combined with phenolic acid (cinnamic acid or vanillic acid), cinnamic acid was combined with vanillic acid or the three organic acids combined, their inhibition effect on M. aeruginosa was enhanced; (4) the combination of fatty acid and phenol acidification either in the same kind or among different kinds can enhance the effect of algal inhibition. Conclusion The three allelochemicals extracted from the rhizome of P. cordata might have good algae inhibition effect and the combined action of various allelochemicals might be the main mechanism of P. cordata inhibiting cyanobacteria bloom. Therefore, succinic acid, cinnamic acid and vanillic acid have the potential to be developed as algal inhibitors. [Ch, 2 fig. 2 tab. 26 ref.]