Hi all…as drinking water professionals we have turned our attention to the latest potential threats including for example microplastics, perfluorinated compounds, and cyanobacterial toxins. In the case of cyanobacterial toxins in freshwater the focus has been on microcystin, cylindrospermopsin, and anatoxin-a. Those in disciplines more familiar with cyanotoxins are also very aware and knowledgeable about toxic bioactive peptides (TBPs). A recently published paper helps to bring us up to speed on metabolites (breakdown products of these toxins) which may be formed during treatment. This study “compared temporal and spatial trends of four MCs (MCLR, MCRR, MCYR, MCLA), three cyanopeptolins (Cpt1020, Cpt1041, Cpt1007), two anabaenopeptins (AptF, AptB), and microginins (Mgn690) in raw drinking water and at six surface water locations above these drinking water intakes in a eutrophic lake. All four MC congeners and five of six TBPs were detected in lake and raw drinking water.” The samples were collected in and around Lake Winnebago, Wisconsin, so parallels with Canadian drinking water sources and treatment may be expected.
The authors conclude that “this study expands current information about cyanobacterial toxic bioactive peptides that occur in lakes and that enter drinking water treatment plants and underscores the need to determine the fate of less studied cyanobacterial metabolites during drinking water treatment that may exacerbate toxicity of more well-known cyanobacterial toxins.”
Bill
Analysis of cyanobacterial metabolites in surface and raw drinking waters reveals more than microcystin
Lucas J. Beversdorf, Kayla Rude, Chelsea A. Weirich , Sarah L. Bartlett, Mary Seaman, Christine Kozik, Peter Biese, Timothy Gosz, Michael Suha, Christopher Stempa, Christopher Shaw, Curtis Hedman, Joseph J. Piatt, and Todd R. Miller
Water Research, Volume 140, 1 September 2018, Pages 280-290
https://doi.org/10.1016/j.watres.2018.04.032
Abstract
“Freshwater cyanobacterial blooms are becoming increasingly problematic in regions that rely on surface waters for drinking water production. Microcystins (MCs) are toxic peptides produced by multiple cyanobacterial genera with a global occurrence. Cyanobacteria also produce a variety of other toxic and/or otherwise bioactive peptides (TBPs) that have gained less attention including cyanopeptolins (Cpts), anabaenopeptins (Apts), and microginins (Mgn). In this study, we compared temporal and spatial trends of four MCs (MCLR, MCRR, MCYR, MCLA), three Cpts (Cpt1020, Cpt1041, Cpt1007), two Apts (AptF, AptB), and Mgn690 in raw drinking water and at six surface water locations above these drinking water intakes in a eutrophic lake. All four MC congeners and five of six TBPs were detected in lake and raw drinking water. Across all samples, MCLR was the most frequently detected metabolite (100% of samples) followed by MCRR (97%) > Cpt1007 (74%) > MCYR (69%) > AptF (67%) > MCLA (61%) > AptB (54%) > Mgn690 (29%) and Cpt1041 (15%). Mean concentrations of MCs, Apts, and Cpts into two drinking water intakes were 3.9 ± 4.7, 0.14 ± 0.21, and 0.38 ± 0.92, respectively. Mean concentrations in surface water were significantly higher (p < 0.05) than in drinking water intakes for MCs but not for Cpts and Apts. Temporal trends in MCs, Cpts, and Apts in the two raw drinking water intakes were significantly correlated (p < 0.05) with measures of cell abundance (chlorophyll-a, Microcystis cell density), UV absorbance, and turbidity in surface water. This study expands current information about cyanobacterial TBPs that occur in lakes and that enter drinking water treatment plants and underscores the need to determine the fate of less studied cyanobacterial metabolites during drinking water treatment that may exacerbate toxicity of more well-known cyanobacterial toxins.”
