Multiple cyanotoxin congeners produced by sub-dominant cyanobacterial taxa in riverine cyanobacterial and algal mats.

Benthic cyanobacterial proliferations in rivers are have been reported with increasing frequency worldwide. In the Eel and Russian rivers of California, more than a dozen dog deaths have been attributed to cyanotoxin toxicosis since 2000. Periphyton proliferations in these rivers comprise multiple c...

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Main Authors: Laura T Kelly, Keith Bouma-Gregson, Jonathan Puddick, Rich Fadness, Ken G Ryan, Timothy W Davis, Susanna A Wood
Format: Article
Language:English
Published: Public Library of Science (PLoS) 2019-01-01
Series:PLoS ONE
Online Access:https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0220422&type=printable
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author Laura T Kelly
Keith Bouma-Gregson
Jonathan Puddick
Rich Fadness
Ken G Ryan
Timothy W Davis
Susanna A Wood
author_facet Laura T Kelly
Keith Bouma-Gregson
Jonathan Puddick
Rich Fadness
Ken G Ryan
Timothy W Davis
Susanna A Wood
author_sort Laura T Kelly
collection DOAJ
description Benthic cyanobacterial proliferations in rivers are have been reported with increasing frequency worldwide. In the Eel and Russian rivers of California, more than a dozen dog deaths have been attributed to cyanotoxin toxicosis since 2000. Periphyton proliferations in these rivers comprise multiple cyanobacterial taxa capable of cyanotoxin production, hence there is uncertainty regarding which taxa are producing toxins. In this study, periphyton samples dominated by the cyanobacterial genera Anabaena spp. and Microcoleus spp. and the green alga Cladophora glomerata were collected from four sites in the Eel River catchment and one site in the Russian River. Samples were analysed for potential cyanotoxin producers using polymerase chain reaction (PCR) in concert with Sanger sequencing. Cyanotoxin concentrations were measured using liquid chromatography tandem-mass spectrometry, and anatoxin quota (the amount of cyanobacterial anatoxins per toxigenic cell) determined using droplet digital PCR. Sequencing indicated Microcoleus sp. and Nodularia sp. were the putative producers of cyanobacterial anatoxins and nodularins, respectively, regardless of the dominant taxa in the mat. Anatoxin concentrations in the mat samples varied from 0.1 to 18.6 μg g-1 and were significantly different among sites (p < 0.01, Wilcoxon test); however, anatoxin quotas were less variable (< 5-fold). Dihydroanatoxin-a was generally the most abundant variant in samples comprising 38% to 71% of the total anatoxins measured. Mats dominated by the green alga C. glomerata contained both anatoxins and nodularin-R at concentrations similar to those of cyanobacteria-dominated mats. This highlights that even when cyanobacteria are not the dominant taxa in periphyton, these mats may still pose a serious health risk and indicates that more widespread monitoring of all mats in a river are necessary.
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spelling doaj.art-1f4c32360a094c98a37e175c2d2666b52025-03-02T05:34:17ZengPublic Library of Science (PLoS)PLoS ONE1932-62032019-01-011412e022042210.1371/journal.pone.0220422Multiple cyanotoxin congeners produced by sub-dominant cyanobacterial taxa in riverine cyanobacterial and algal mats.Laura T KellyKeith Bouma-GregsonJonathan PuddickRich FadnessKen G RyanTimothy W DavisSusanna A WoodBenthic cyanobacterial proliferations in rivers are have been reported with increasing frequency worldwide. In the Eel and Russian rivers of California, more than a dozen dog deaths have been attributed to cyanotoxin toxicosis since 2000. Periphyton proliferations in these rivers comprise multiple cyanobacterial taxa capable of cyanotoxin production, hence there is uncertainty regarding which taxa are producing toxins. In this study, periphyton samples dominated by the cyanobacterial genera Anabaena spp. and Microcoleus spp. and the green alga Cladophora glomerata were collected from four sites in the Eel River catchment and one site in the Russian River. Samples were analysed for potential cyanotoxin producers using polymerase chain reaction (PCR) in concert with Sanger sequencing. Cyanotoxin concentrations were measured using liquid chromatography tandem-mass spectrometry, and anatoxin quota (the amount of cyanobacterial anatoxins per toxigenic cell) determined using droplet digital PCR. Sequencing indicated Microcoleus sp. and Nodularia sp. were the putative producers of cyanobacterial anatoxins and nodularins, respectively, regardless of the dominant taxa in the mat. Anatoxin concentrations in the mat samples varied from 0.1 to 18.6 μg g-1 and were significantly different among sites (p < 0.01, Wilcoxon test); however, anatoxin quotas were less variable (< 5-fold). Dihydroanatoxin-a was generally the most abundant variant in samples comprising 38% to 71% of the total anatoxins measured. Mats dominated by the green alga C. glomerata contained both anatoxins and nodularin-R at concentrations similar to those of cyanobacteria-dominated mats. This highlights that even when cyanobacteria are not the dominant taxa in periphyton, these mats may still pose a serious health risk and indicates that more widespread monitoring of all mats in a river are necessary.https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0220422&type=printable
spellingShingle Laura T Kelly
Keith Bouma-Gregson
Jonathan Puddick
Rich Fadness
Ken G Ryan
Timothy W Davis
Susanna A Wood
Multiple cyanotoxin congeners produced by sub-dominant cyanobacterial taxa in riverine cyanobacterial and algal mats.
PLoS ONE
title Multiple cyanotoxin congeners produced by sub-dominant cyanobacterial taxa in riverine cyanobacterial and algal mats.
title_full Multiple cyanotoxin congeners produced by sub-dominant cyanobacterial taxa in riverine cyanobacterial and algal mats.
title_fullStr Multiple cyanotoxin congeners produced by sub-dominant cyanobacterial taxa in riverine cyanobacterial and algal mats.
title_full_unstemmed Multiple cyanotoxin congeners produced by sub-dominant cyanobacterial taxa in riverine cyanobacterial and algal mats.
title_short Multiple cyanotoxin congeners produced by sub-dominant cyanobacterial taxa in riverine cyanobacterial and algal mats.
title_sort multiple cyanotoxin congeners produced by sub dominant cyanobacterial taxa in riverine cyanobacterial and algal mats
url https://journals.plos.org/plosone/article/file?id=10.1371/journal.pone.0220422&type=printable
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