摘要

The neurotoxin anatoxin-a (ANTX-a), one of the most common cyanotoxin, poses a health risk to people and can be lethal to aquatic organisms. This paper presents results on its bioremediation by the aquatic macrophyte Lemna trisulca. We show that the plant is resistant to the harmful impact of toxin and is capable of removing ANTX-a from water. Some of the ANTX-a concentrations which were used in our experiments were much higher than those found in natural conditions. The exposition of L. trisulca to 2.5 mu g ANTX-a/mL did not affect its biomass accumulation within 24 d. Significant decreases in biomass content by 21% and 30% were demonstrated in samples cultivated in media containing 12.5 mu g ANTX-a/mL after 18 and 24 day of experiment, respectively. One gram of fresh weight (f.w.) of L trisulca cultured for 14 d in the media containing 50 jig ANTX-a removed 95% of the initial toxin concentration; for media with 250 jig ANTX-a, 86% was removed. In tests of ANTX-a binding stability and degradation we transferred the macrophyte to fresh media without added toxin; within 14 d the content of accumulated ANTX-a in the macrophyte decreased by 76% (from initial 19.3 mu g ANTX-a/g f.w.), 71% (from 37.3 mu g ANTX-a/g f.w.) and 47% (from 63.7 mu g ANTX-a/g f.w.). The quantity of ANTX-a released to media was minimal: from 3.5% to 5.1% of the initial bioaccumulated value. The data show that part of the ANTX-a was degraded. Mass spectra analyses did not indicate transformation of ANTX-a to already known forms. These findings suggest that L trisulca has much potential as a phytoremediation agent for stabilization of aquatic environments.

  • 出版日期2014-10

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