The ecological stoichiometry of toxins produced by harmful cyanobacteria: an experimental test of the carbon-nutrient balance hypothesis

• Published in: Ecology letters Vol. 12; no. 12; pp. 1326 - 1335
• Main Authors: Van de Waal, Dedmer B., Verspagen, Jolanda M. H., Lürling, Miquel, Van Donk, Ellen, Visser, Petra M., Huisman, Jef
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.12.2009; Blackwell
• Subjects: analysis; Animal and plant ecology; Animal, plant and microbial ecology; Applied ecology; Bacteria; Biological and medical sciences; biosynthesis; carbon; Carbon dioxide; Carbon Dioxide - metabolism; carbon-nutrient balance hypothesis; Chemical composition; climate change; Cyanobacteria; C : N ratio; ecological stoichiometry; Ecology; Ecotoxicology, biological effects of pollution; elemental composition; eutrophication; Experiments; Fresh Water; Fresh Water - analysis; Fundamental and applied biological sciences. Psychology; General aspects; harmful algal blooms; Lakes; metabolism; Metabolites; Microcystins; Microcystins - biosynthesis; Microcystis; Microcystis - metabolism; Microcystis aeruginosa; nitrates; Nitrogen; Nitrogen - metabolism; Nitrogen enrichment; Nutrient balance; Nutrients; Secondary metabolites; stoichiometry; Toxicology; Toxins; trophic relationships; Water Microbiology; Stoichiometry; Experimental test; Metabolite; Toxicity; Carbon dioxide; Trophic status; Carbon balance; Eutrophication; secondary metabolites; Cyanobacteria; Bacteria; Secondary metabolism; harmful algal blooms; Microcystis aeruginosa; Ecotoxicology; C: N ratio; Algae; Ecology; ecological stoichiometry; Dynamical climatology; Climate change; Carbon nitrogen ratio; Toxin; carbon-nutrient balance hypothesis; microcystins; Global change; Bloom; Nutrient; Water pollution; Harmful alga
• ISSN: 1461-023X; 1461-0248; 1461-0248
• DOI: 10.1111/j.1461-0248.2009.01383.x

Ecology Letters (2009) 12: 1326–1335 The elemental composition of primary producers reflects the availability of light, carbon and nutrients in their environment. According to the carbon‐nutrient balance hypothesis, this has implications for the production of secondary metabolites. To test this hypothesis, we investigated a family of toxins, known as microcystins, produced by harmful cyanobacteria. The strain Microcystis aeruginosa HUB 5‐2‐4, which produces several microcystin variants of different N:C stoichiometry, was cultured in chemostats supplied with various combinations of nitrate and CO2. Excess supply of both nitrogen and carbon yielded high cellular N:C ratios accompanied by high cellular contents of total microcystin and the nitrogen‐rich variant microcystin‐RR. Comparable patterns were found in Microcystis‐dominated lakes, where the relative microcystin‐RR content increased with the seston N:C ratio. In total, our results are largely consistent with the carbon‐nutrient balance hypothesis, and warn that a combination of rising CO2 and nitrogen enrichment will affect the microcystin composition of harmful cyanobacteria.