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Diazotrophy modulates cyanobacteria stoichiometry through functional traits that determine bloom magnitude and toxin production.

ABSTRACT: Harmful cyanobacterial blooms are an increasing threat to water quality. The interactions between two eco-physiological functional traits of cyanobacteria, diazotrophy (nitrogen (N)-fixation) and N-rich cyanotoxin synthesis, have never been examined in a stoichiometric explicit manner. We explored how a gradient of resource N:phosphorus (P) affects the biomass, N, P stoichiometry, light-harvesting pigments, and cylindrospermopsin production in a N-fixing cyanobacterium, Aphanizomenon. Low N:P Aphanizomenon cultures produced the same biomass as populations grown in high N:P cultures. The biomass accumulation determined by carbon, indicated low N:P Aphanizomenon cultures did not have a N-fixation growth tradeoff, in contrast to some other diazotrophs that maintain stoichiometric N homeostasis at the expense of growth. However, N-fixing Aphanizomenon populations produced less particulate cylindrospermopsin and had undetectable dissolved cylindrospermopsin compared to non-N-fixing populations. The pattern of low to high cyanotoxin cell quotas across an N:P gradient in the diazotrophic cylindrospermopsin producer is similar to the cyanotoxin cell quota response in non-diazotrophic cyanobacteria. We suggest that diazotrophic cyanobacteria may be characterized into two broad functional groups, the N-storage-strategists and the growth-strategists, which use N-fixation differently and may determine patterns of bloom magnitude and toxin production in nature.

SUBMITTER: Wagner ND

PROVIDER: S-EPMC9937718 | biostudies-literature | 2023 Feb

REPOSITORIES: biostudies-literature

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Diazotrophy modulates cyanobacteria stoichiometry through functional traits that determine bloom magnitude and toxin production.

Wagner Nicole D ND Osburn Felicia S FS Taylor Raegyn B RB Back Jeffrey A JA Chambliss C Kevin CK Brooks Bryan W BW Scott J Thad JT

Limnology and oceanography 20221124 2

Harmful cyanobacterial blooms are an increasing threat to water quality. The interactions between two eco-physiological functional traits of cyanobacteria, diazotrophy (nitrogen (N)-fixation) and N-rich cyanotoxin synthesis, have never been examined in a stoichiometric explicit manner. We explored how a gradient of resource N:phosphorus (P) affects the biomass, N, P stoichiometry, light-harvesting pigments, and cylindrospermopsin production in a N-fixing cyanobacterium, <i>Aphanizomenon</i>. Low ...[more]

PMID: 36819961

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Dataset Information

Diazotrophy modulates cyanobacteria stoichiometry through functional traits that determine bloom magnitude and toxin production.

Publications

Diazotrophy modulates cyanobacteria stoichiometry through functional traits that determine bloom magnitude and toxin production.

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