US EPA

7427298 

Journal Article 

Novel cyanotoxin-producing Synechococcus in tropical lakes 

Gin, KY; Sim, ZY; Goh, KC; Kok, JWK; Te, SH; Tran, NH; Li, W; He, Y; , 

2021 

1 

Water Research
ISSN: 0043-1354
EISSN: 1879-2448 

PERGAMON-ELSEVIER SCIENCE LTD 

OXFORD 

192 

116828 

English 

33508721 

10.1016/j.watres.2021.116828 

WOS:000620649400013 

https://linkinghub.elsevier.com/retrieve/pii/S0043135421000269
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Picocyanobacteria are small cyanobacteria, being about 0.8-1.5 µm in size. They are present in freshwater environments all over the world and are known to cause harmful algal blooms, although their effects are not well understood. Algal blooms are important to manage because they threaten freshwater resources, with potentially severe effects on ecological and human health. There is also increased urgency due to urbanization and climate change trends which are expected to exacerbate these bloom dynamics. These changes are expected to especially favour picocyanobacteria groups, emphasizing the need for better characterization of their effects in the environment. In this study, we report the discovery that Synechococcus sp. could produce cylindrospermopsin (CYN) and anatoxin-a (ATX). This ability had never been previously reported for this species. Their toxin genes were also partial compared to other major producers such as Raphidiopsis sp. and Anabaena sp., demonstrating potentially unique synthesis pathways that provides insight into the various mechanisms of genetic variation that drives toxin synthesis. The Synechococcus sp. strains were found to produce about 9.0 × 10-5-6.8 × 10-4 fg CYN cell-1 and 4.7 × 10-4-1.5 × 10-2 fg ATX cell-1. The potential for Synechococcus sp. to be toxic highlights a global concern due to its widespread distribution, and through environmental trends that increasingly favour its productivity within freshwater systems around the world. 

Anatoxin-a; Climate change; Cyanobacteria; Cylindrospermopsin; Harmful algal blooms; Synechococcus; Climate change; Genes; Tropics; Cylindrospermopsin; Environmental trends; Fresh water resources; Freshwater environments; Freshwater systems; Harmful algal blooms; Picocyanobacteria; Synthesis pathways; Water; anatoxin a; cylindrospermopsin; fresh water; bacterial toxin; uracil; algal bloom; cyanobacterium; freshwater; genetic variation; lacustrine environment; picoplankton; toxin; urbanization; algal bloom; Anabaena; Article; bacterial gene; bacterial strain; bacterium isolate; climate change; controlled study; genetic variation; lake; nonhuman; priority journal; Raphidiopsis; Singapore; species distribution; Synechococcus; toxin analysis; toxin synthesis; genetics; human; Anabaena sp.; Cyanobacteria; Raphidiopsis; Synechococcus; Synechococcus sp.; Bacterial Toxins; Harmful Algal Bloom; Humans; Lakes; Synechococcus; Uracil