State of knowledge and concerns on cyanobacterial blooms and cyanotoxins.

By S. Merel, D. Walker, Ruth Chicana, S. Snyder, E. Baurès, O. Thomas. Environment International, 2013

879 citations recorded by the source corpus.

Cyanobacteria are ubiquitous microorganisms considered as important contributors to the formation of Earth's atmosphere and nitrogen fixation. However, they are also frequently associated with toxic blooms. Indeed, the wide range of hepatotoxins, neurotoxins and dermatotoxins synthesized by these bacteria is a growing environmental and public health concern. This paper provides a state of the art on the occurrence and management of harmful cyanobacterial blooms in surface and drinking water, including economic impacts and research needs. Cyanobacterial blooms usually occur according to a combination of environmental factors e.g., nutrient concentration, water temperature, light intensity, salinity, water movement, stagnation and residence time, as well as several other variables. These environmental variables, in turn, have promoted the evolution and biosynthesis of strain-specific, gene-controlled metabolites (cyanotoxins) that are often harmful to aquatic and terrestrial life, including humans. Cyanotoxins are primarily produced intracellularly during the exponential growth phase. Release of toxins into water can occur during cell death or senescence but can also be due to evolutionary-derived or environmentally-mediated circumstances such as allelopathy or relatively sudden nutrient limitation. Consequently, when cyanobacterial blooms occur in drinking water resources, treatment has to remove both cyanobacteria (avoiding cell lysis and subsequent toxin release) and aqueous cyanotoxins previously released. Cells are usually removed with limited lysis by physical processes such as clarification or membrane filtration. However, aqueous toxins are usually removed by both physical retention, through adsorption on activated carbon or reverse osmosis, and chemical oxidation, through ozonation or chlorination. While the efficient oxidation of the more common cyanotoxins (microcystin, cylindrospermopsin, anatoxin and saxitoxin) has been extensively reported, the chemical and toxicological characterization of their by-products requires further investigation. In addition, future research should also investigate the removal of poorly considered cyanotoxins (β-methylamino-alanine, lyngbyatoxin or aplysiatoxin) as well as the economic impact of blooms.

Subfields: Ecology, Evolution, Behavior and Systematics, Environmental Chemistry

View Paper: https://www.semanticscholar.org/paper/148ab651e3e9d6dfe144376f3448fd2eeb5e09a9

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Ecology, Evolution, Behavior and Systematics

In Environmental Chemistry

Citations in the corpus

Harmful Algal Blooms (2015, background): “…while CYL, a polycyclic uracil derivative, is reported from blooms of Cylindrospermopsis raciborskii, Umezakia natans, and Aphanizomenon ovalisporum and frequently reported in the southern United States, Australia, and Europe (Westrick, 2008; Merel et al., 2013a,b; Rzymski and Poniedziałek, 2014).”
Emerging threats and persistent conservation challenges for freshwater biodiversity (2018, background): “One environmental toxin that has gained considerable attention is the amino acid β -N-methylamino-L-alanine (BMAA) (Brand et al. , 2010; Merel et al. , 2013).”
Algal bloom and its economic impact (2016, background): “Additional factors influencing their life are water temperature, pH, climate changes, salinity, water column stability and anthropogenic modifications of aquatic environment including nutrients over-enrichment (eutrophication) [2, 3].”
Still challenging: the ecological function of the cyanobacterial toxin microcystin – What we know so far (2018, background): “Therefore, a vast amount of research has been focused on the harmful effects of MCs on humans, animals, and aquatic organisms, while their natural physiological and/or ecological functions remain unclear (Merel et al., 2013a,b).”