Distribution of toxigenic cyanobacteria in Alpine lakes and rivers as revealed by molecular screening

Jablonska, Maša (author), Cerasino, Leonardo (author), Boscaini, Adriano (author), Capelli, Camilla (author), Greco, Claudia (author), Krivograd-Klemenčič, Aleksandra (author), Mischke, Ute (author), Salmaso, Nico (author), Kurmayer, Rainer (author)

The increasing frequency of cyanobacteria blooms in waterbodies caused by ecosystem eutrophication could endanger human health. This risk can be mitigated by effective monitoring incorporating molecular methods. To date, most molecular studies on toxigenic cyanobacteria have been limited to microcystins (MCs), disregarding other cyanotoxins, to freshwater planktic habitats while ignoring benthic habitats, and to limited geographic areas (usually one or a few specific waterbodies). In this study, we used PCR-based methods including PCR product sequencing and chemical-analytical methods (LC-MS/MS) to screen many plankton (n = 123) and biofilm samples (n = 113) originating from 29 Alpine lakes and 18 rivers for their cyanotoxin production potential. Both mcyE (indicating MC synthesis) and anaC (indicating anatoxin (ATX) synthesis) gene fragments were able to qualitatively predict MC or ATX occurrence. The abundance of mcyE gene fragments was significantly related to MC concentrations in plankton samples (R2 = 0.61). mcyE gene fragments indicative of MC synthesis were most abundant in planktic samples (65 %) and were assigned to the genera Planktothrix and Microcystis. However, mcyE rarely occurred in biofilms of lakes and rivers, i.e., 4 % and 5 %, respectively, and were assigned to Microcystis, Planktothrix, and Nostoc. In contrast, anaC gene fragments occurred frequently in planktic samples (14 % assigned to Tychonema, Phormidium (Microcoleus), and Oscillatoria), but also in biofilms of lakes (49 %) and rivers (18 %) and were assigned to the genera Phormidium, Oscillatoria, and Nostocales. The cyrJ gene fragment indicating cylindrospermopsin synthesis occurred only once in plankton (assigned to Dolichospermum), while saxitoxin synthesis potential was not detected. For plankton samples, monomictic and less eutrophic conditions were positively related to mcyE/MC occurrence frequency, while oligomictic conditions were related to anaC/ATX frequency. The anaC/ATX frequency in biofilm was related to the lake habitats generally showing higher biodiversity as revealed from metabarcoding in a parallel study.

• Language: English
• Keywords: cyanotoxins, planktic and benthic habitats, water quality monitoring, early warning, toxigenic cyanobacteria, European Alps
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2024
• Number of pages: Str. [1]-11
• Numbering: Vol. 258, [art. no.] ǂ121783
• PID: 20.500.12556/RUL-182179
• UDC: 579
• ISSN on article: 0043-1354
• DOI: 10.1016/j.watres.2024.121783
• COBISS.SI-ID: 197565187
• Publication date in RUL: 29.04.2026
• Collection: This document is a collection and includes 1 document.

Record is a part of a journal

• Title: Water research
• Shortened title: Water res.
• Publisher: Elsevier
• ISSN: 0043-1354
• COBISS.SI-ID: 26617344

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: cianotoksini, planktonski in bentoški habitati, monitoring kakovosti voda, zgodnje zaznavanje, toksigene cianobakterije, Alpe