Department Environmental Chemistry

CyanoBloom

Photo: Francesco Pomarti, Marta Reyes (Eawag, ECO)
Greifensee Model Lake, Switzerland

Why do toxic cyanobacteria bloom? A gene to ecosystem approach.

This project aims to understand the ecological and evolutionary mechanisms triggering harmful cyanobacterial blooms (cyanoHABs) in lake ecosystems, and develop predictive models. We propose a synchronised and synergistic research effort by an interdisciplinary team of experts in ecology, microbiology, environmental chemistry, and dynamical systems theory, to address several central questions about the mechanisms triggering cyanoHABs. We integrate a suite of field observations, experiments, and models (data-driven and mechanistic) to capture the temporal and biological scales of processes leading to the emergence of cyanoHABs. We focus on the interaction between physiological, ecological and evolutionary mechanisms, and the relative costs and benefits that cyanoHAB taxa have from producing non-ribosomal peptides (NRPs) in a community context and over natural environmental gradients.

More information and updates on: www.cyanobloom.ch

Photo: Stefanie Merkli (Eawag, ECO)
Greifensee Monitoring Station, Switzerland


Reserach Groups involved:

Elisabeth Janssen: Environmental Chemistry of Biomolecules

David Johnson: Synthetic Microbial Biology

Rudolf Rohr: Theoretical Ecology and Evolution 

Francesco Pomati: Plankton Ecology

Photo: Stefanie Merkli (Eawag, ECO)
Sinergia CyanoBloom project Team 2022

External collaborators

Dr. Rodolf Rohr (UniFr)
Dr. Phoung Nguyen (UniFr)

 

Other collaborators

Olga Schubert, Eawag, Dept. Umik

Publication

Tracking extensive portfolio of cyanotoxins in five-year lake survey and identifying indicator metabolites of cyanobacterial taxa

Cyanobacterial blooms require monitoring, as they pose a threat to ecosystems and human health, especially by the release of toxins. Along with widely reported microcystins, cyanobacteria coproduce other bioactive metabolites; however, information about their dynamics in surface waters is sparse. We investigated dynamics across full bloom successions throughout a five-year lake monitoring campaign (Greifensee, Switzerland) spanning 150 sampling dates. We conducted extensive suspect screening of cyanobacterial metabolites using the database CyanoMetDB. Across all 850 samples, 35 metabolites regularly co-occurred. Microcystins were present in 70% of samples, with [d-Asp3,(E)-Dhb7]MC-RR reaching concentrations of 70 ng/L. Anabaenopeptins, meanwhile, were detected in 95% of all samples with concentrations of Oscillamide Y up to 100-fold higher than microcystins. Based on LC-MS response and frequency, we identified indicator metabolites exclusively produced by one of three cyanobacteria isolated from the lake, these being [d-Asp3,(E)-Dhb7]MC-RR from Planktothrix sp. G2020, Microginin 761B from Microcystis sp. G2011, and Ferintoic acid B from Microcystis sp. G2020. These indicators showed distinct temporal trends and peaking seasons that reflect the variance in either the abundance of the producing cyanobacteria or their toxin production dynamics. Our approach demonstrates that selecting high LC-MS response and frequent and species-specific indicator metabolites can be advantageous for cyanobacterial monitoring.
Wang, X.; Wullschleger, S.; Jones, M.; Reyes, M.; Bossart, R.; Pomati, F.; Janssen, E. M. -L. (2024) Tracking extensive portfolio of cyanotoxins in five-year lake survey and identifying indicator metabolites of cyanobacterial taxa, Environmental Science and Technology, 58(37), 16560-16569, doi:10.1021/acs.est.4c04813, Institutional Repository