PM06 Emerging Pollutants
Exhibit Hall
8:00 AM - Monday
(PM055) Environmental fate of cyanotoxins in the Eastern Lake Erie: Simulating the biodegradation of microcystins in a lab-scale bioreactor.
Perez, S.1, Eichhorn, P.1, Aga, D.1, 1 State University of New York at Buffalo, Buffalo, NY, USA
ABSTRACT- From 1999 - 2002, large mortalities of waterfowl and fish have been observed in Lake Erie, particularly in the Eastern basin. Botulism type E (produced by Clostridium botulinum type E) has been connected to these events. The conditions that have prompted the establishment of C. botulinum type E in Lake Erie are not understood at all, and many factors that may be involved are not yet addressed by any of the ongoing studies. Growth of botulisms-inducing micro-organism is believed to be favoured by changes in microbial (sediment) community under the influence of anthropogenic contaminants (antibiotics originating from animal use, fish farming or human consumption; via sewage or surface run-off) and natural toxins such as cyanotoxins. Previous studies indicate a strong association between the bacterial environment favoring C. botulinum Type E and the presence of cyanobacterial blooms. To improve the understanding of the exposure of aquatic lifeforms to cyanotoxins released during algal bloom, their environmental fate is needed to be investigated. In view of the lack of data on the biotic breakdown of microcystins, studies were conducted on the biodegradability of microcystin-YR, microcystin-LR, and microcystin-RR in a laboratory-scale bioreactor simulating surface waters conditions. The bioreactor was spiked with individual compounds as well as in combination at environmentally relevant concentrations in order to compare their primary degradation. Tentative identification of biodegradation intermediates was performed with liquid chromatography-ion trap-mass spectrometry after sample enrichment on solid-phase extraction cartridges.
Key words: degradation, microcystins, mass spectrometry