Benthic cyanobacteria: A source of cylindrospermopsin and microcystin in Australian drinking water reservoirs. (1st November 2017)

• Record Type: Journal Article
• Authors: Gaget, Virginie; Humpage, Andrew R.; Huang, Qiong; Monis, Paul; Brookes, Justin D.
• Is Part Of: Water research. Volume 124(2017)
• Page Start: 454
• Page End: 464
• Publication Date: 2017-11-01
• Subjects: Benthic cyanobacteria -- Microcystin -- Cylindrospermopsin -- Drinking water; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2017.07.073
• Languages: English
• ISSNs: 0043-1354

Abstract

Abstract: Cyanobacteria represent a health hazard worldwide due to their production of a range of highly potent toxins in diverse aquatic environments. While planktonic species have been the subject of many investigations in terms of risk assessment, little is known about benthic forms and their impact on water quality or human and animal health. This study aimed to purify isolates from environmental benthic biofilms sampled from three different drinking water reservoirs and to assess their toxin production by using the following methods: Enzyme-Linked Immunosorbent Assay (ELISA), High-Performance Liquid Chromatography (HPLC), Liquid Chromatography–Tandem Mass Spectrometry (LC-MS/MS) and quantitative PCR (qPCR). Microscopic observation of the isolates allowed the identification of various filamentous cyanobacterial genera: Anabaena (benthic form), Calothrix and Nostoc from the Nostocales and Geitlerinema, Leptolyngbya, Limnothrix, Lyngbya, Oxynema, Phormidium and Pseudanabaena representing non-heterocystous filamentous cyanobacteria. The Phormidium ambiguum strain AWQC-PHO021 was found to produce 739 ng/mg of dry weight (d/w) of cylindrospermopsin and 107 ng/mg (d/w) of deoxy-cylindrospermopsin. The Nostoc linckia strain AWQC-NOS001 produced 400 ng/mg (d/w) of a microcystin analogue. This is the first report of hepatotoxin production by benthic cyanobacteria in temperate Australian drinking water reservoirs. These findings indicate that water quality monitoring programs need to consider benthic cyanobacteria as a potential source of toxins. Highlights: Benthic hepatotoxins were detected in temperate Australian reservoirs. Phormidium was shown to produce cylindrospermopsins. Nostoc linckia was highlighted as a microcystin-producer in benthic mats.