First report of microcystin‐LR in the cyanobacterium Gloeotrichia echinulata

Abstract

Gloeotrichia echinulata is a bloom-forming cyanobacterium that is common in eutrophic lakes, and less prevalent but increasing in oligotrophic lakes. We used an enzyme-linked immunosorbent assay analysis to test for the presence of the hepatotoxin microcystin-LR (MC-LR) in G. echinulata collected from an oligotrophic lake in central New Hampshire, USA. We found that G. echinulata contained MC-LR at mean concentrations of 97.07 +/- 7.78 (1 s.e.) ng MC-LR g(-1) dry wt colonies. This suggests that recent outbreaks of G. echinulata in oligotrophic lakes used as water sources throughout New England (USA) may pose a health concern. The toxicity of G. echinulata reported here suggests the need for future monitoring of microcystins in oligotrophic lakes.

The Fate of Microcystins in the Environment and Challenges for Monitoring

“…Dilution of microcystins occurs when they are introduced to a large volume of water, such as that of a lake. However, dilution may not always reduce microcystin abundance below the critical point for organisms, as some deep oligotrophic lakes are also subject to toxic algal blooms [ 38 ]. Breakdown of microcystins due to high temperatures has also been cited as a means for detoxification [ 23 , 39 ].…”

Substratum‐Associated Microbiota

“…The first confirmation of an anatoxin-a-producing species in the Southern Hemisphere and the first report of anatoxin-a production by Aphanizomenon issatschenkoi was confirmed by phylogenetic analysis of the 16S rRNA gene sequence (Wood et al, 2007). Microcystin-LR was found in a cyanobacterium, Gloeotrichai echinulata, in an oligotrophic lake in New Hampshire, USA, using enzymelinked immunosorbent assay analysis (Carey et al, 2007a). Kiemle et al (2007) studied the chemical composition of extracellular polymeric substances secreted by desmids and used for adhesion, gliding and biofilm formation.…”

Microcystins, nutrient dynamics, and other environmental factors during blooms of non-microcystin-producingAphanizomenon flos-aquaein Upper Klamath Lake, Oregon, 2009

“…When present, M. aeruginosa was observed by field personnel as a thin film on the lake surface and as accumulations along the leeward shore during daily high wind events. G. echinulata, a known microcystin producer (Carey et al 2007), first appeared in sediment trap samples on 29 July, so there may be some contribution from this species to the occurrence of microcystins in the lake.…”