The Removal of Cyanobacterial Hepatotoxin [Dha(7)] Microcystin-LR via Bioaccumulation in Water Lettuce (Pistia stratiotes L.)

摘要

The removal of [Dha(7)] microcystin-LR through bioaccumulation in six aquatic plants was investigated. The aquatic plant water lettuce (Pistia stratiotes L.) exhibited the highest removal, with 13 % of the toxin remaining after a 7-day exposure period. Removal by P. stratiotes (with 0.5 and 1.0 mg/L of the toxin) was faster and greater in static systems than in continuous flow systems. In the static experiment, P. stratiotes roots accumulated [Dha(7)] microcystin-LR up to a concentration of 0.0088 ng/mg wet wt. plant material, whereas in the continuous flow system, the plant root tissue accumulated the toxin up to a concentration of 0.0041 ng/mg wet wt. plant material. Exposure to the toxin at concentrations of 0.5 and 1.0 mg/L induced changes in the development of P. stratiotes, including short, thin and rotted roots with decreased leaf counts after 3 days of exposure.