Appendix 3: Tables of Microcystins and Nodularins

Spoof, Lisa; Catherine, Arnaud

doi:10.1002/9781119068761.app3

Cited by 97 publications

(80 citation statements)

References 88 publications

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“…Individual strains produced a maximum of 12 microcystins. This number must be placed in relation to the more than 240 microcystins that have been previously described in microcystin producing cyanobacteria [26]. For example, Microcystis strain CAWBG11 was found to produce 27 different microcystin variants [28], whereas Microcystis strains in other studies [50][51][52] produced less than five microcystins simultaneously.…”

Section: Discussionmentioning

confidence: 99%

“…In Microcystis, the microcystin synthetase gene cluster codes for a hybrid polyketide synthase (PKS)/non-ribosomal peptide synthetase (NRP) enzyme complex, and spans across 55 kb [22,23]. More than 240 microcystin variants have been described in microcystin producing cyanobacteria [26], and contribute to the high diversity of chemotypes reported in Microcystis [27]. The large amount of different structural variants is partly due to variable amino acids in position 2 and 4 in the cyclic structure, but there can also be variations in the other positions [20].…”

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confidence: 99%

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High Diversity of Microcystin Chemotypes within a Summer Bloom of the Cyanobacterium Microcystis botrys

Johansson

Legrand

Björnerås

et al. 2019

Toxins

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The fresh-water cyanobacterium Microcystis is known to form blooms world-wide, and is often responsible for the production of microcystins found in lake water. Microcystins are non-ribosomal peptides with toxic effects, e.g. on vertebrates, but their function remains largely unresolved. Moreover, not all strains produce microcystins, and many different microcystin variants have been described. Here we explored the diversity of microcystin variants within Microcystis botrys, a common bloom-former in Sweden. We isolated a total of 130 strains through the duration of a bloom in eutrophic Lake Vomb, and analyzed their microcystin profiles with tandem mass spectrometry (LC-MS/MS). We found that microcystin producing (28.5%) and non-producing (71.5%) M. botrys strains, co-existed throughout the bloom. However, microcystin producing strains were more prevalent towards the end of the sampling period. Overall, 26 unique M. botrys chemotypes were identified, and while some chemotypes re-occurred, others were found only once. The M. botrys chemotypes showed considerable variation both in terms of number of microcystin variants, as well as in what combinations the variants occurred. To our knowledge, this is the first report on microcystin chemotype variation and dynamics in M. botrys. In addition, our study verifies the co-existence of microcystin and non-microcystin producing strains, and we propose that environmental conditions may be implicated in determining their composition. Key Contribution:This study demonstrates that a single bloom of Microcystis botrys consists of strains with different microcystin chemotypes, each producing from zero up to 12 different microcystin variants. We established that microcystin and non-microcystin producing strains co-occur, and that the chemotype composition varies during the bloom.Toxins 2019, 11, 698 2 of 16 bloom-forming cyanobacteria, and that harmful blooms will increase both in frequency and duration, due to direct and indirect effects of changes in hydrological cycling, increased water temperatures, and nutrient loading [4][5][6][7][8][9].In addition to forming dense blooms which can deteriorate water quality per se, many cyanobacterial genera produce secondary metabolites with significant bioactivity and toxicity to aquatic organisms and humans [10][11][12][13][14]. In freshwaters, microcystins are among the most common cyanotoxins [7,15]. These inhibit the eukaryotic protein phosphatases 1 and 2a, and have hepatotoxic effects in vertebrates [10,16,17]. Drinking water from surface water supplies must therefore be checked for microcystin content, and may not be higher than 1 µg microcystin L −1 according to WHO regulation. Microcystins are cyclic heptapeptides (Figure 1) and are produced by several cyanobacteria including Microcystis, Planktothrix, and Anabaena (Dolichospermum) [14,18,19]. The common structure and biosynthetic pathway of microcystin synthesis in these genera have been described [20][21][22][23][24][25]. In Microcystis, the microcystin synthetase gene cluster co...

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Section: Discussionmentioning

confidence: 99%

mentioning

confidence: 99%

High Diversity of Microcystin Chemotypes within a Summer Bloom of the Cyanobacterium Microcystis botrys

Johansson

Legrand

Björnerås

et al. 2019

Toxins

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“…Furthermore, studies have shown that toxin concentrations are not always related to the density or biomass of species that produce these compounds, as verified by in Pernambuco reservoirs. al., 2017;Spoof and Catherine, 2017) in several genera of cyanobacteria, such as Microcystis, Planktothrix, and Anabaena, among others (Paerl and Otten, 2013). Among these toxins, microcystin-LR (identified in various bloom events in the states of Pernambuco and Paraíba) stands out as the most toxic, frequently found in aquatic ecosystems (Brittain et al, 2000) and associated with several cases of intoxication in both humans (Carmichael et al, 2001;Azevedo et al, 2002), and fish (Chellappa et al, 2008).…”

Section: Wwwjlimnolitmentioning

confidence: 99%

Cyanobacterial blooms in freshwaters bodies in a semiarid region, northeastern Brazil: A review

2017

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Harmful cyanobacterial blooms have caused several problems in freshwater environments due to their prolific growth and the harmful cyanotoxins produced by some species. The occurrence of these organisms has increased in recent decades due to climate change and eutrophication, although most studies are from temperate regions in the Northern hemisphere. This review presents data about cyanobacteria occurrence, dominance, and toxicity events in freshwater bodies in a semiarid region of Northeast Brazil, in the tropical Southern hemisphere. We performed a literature survey of cyanobacteria publications from 1930 to 2016. We made a list of all the dominant species registered in each state, noted their distribution and occurrence of dominance events involving one or more species, and the registered records of toxic blooms, including information about the toxins involved and the range of values. We selected 102 publications that described cyanobacteria Accepted Article www.jlimnol.it occurrence from states in Northeast Brazil; these publications included relevant contributions regarding cyanobacteria distribution, richness, density, and biomass. Forty-nine dominant species were recorded, with the most representation found in the state of Pernambuco (30 spp.). The genera with the highest occurrences were Microcystis, Cylindrospermopsis, Planktothrix, Dolichospermum (=Anabaena), and Geitlerinema, especially the species Cylindrospermopsis raciborskii, Microcystis aeruginosa, and Planktothrix agardhii. Episodes of toxic blooms were observed in four states. Microcystins, cylindrospermopsin, saxitoxins, and anatoxin-a(S) were found to be associated with these blooms. In Northeast Brazil, harmful cyanobacterial blooms are common in urban and public reservoirs. However, in recent years, cyanobacterial blooms in this region have been more intense and perennial, with high biomass occurring throughout the year.

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“…MCs have many structural variations ( i.e. depending on the L-amino acid at the position 2 and 4 respectively from the whole MC architecture), and to date, over 200 MCs variants have been identified (Spoof and Catherine 2017) with different cytotoxic potentials; depending on the tested MCs variants (Shimizu et al 2014). While reports on the biosynthesis and chemical processes of the MCs are constantly in progress, the forces underlying toxin production, i.e.…”

Section: Introductionmentioning

confidence: 99%

Persistence of microcystin production ofPlanktothrix agardhiiexposed to different salinity concentrations

Vergalli

Combès

Franquet

et al. 2018

Preprint

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Recent reports tend to predict the increase of harmful cyanobacteria in water systems worldwide due to the climatic and environmental changes, which would compromise water quality and public health. Among abiotic changes, the higher salinities are expected to promote the growth of some harmful species such as Planktothrix agardhii, which is known to build up blooms in brackish areas. Since P. agardhii is a common cyanotoxin producer (microcystin-producing), we investigated here the growth and tolerance of this species when exposed in vitro to a range of salinity levels, while assessing its microcystins variation and production in batch cultures during a time-frame experiment of 18 days. The study revealed a salt acclimation of the brackish P. agardhii that still produced microcystins in salty cultures while maintaining its growth ability in low to medium salinities (ranged from 0 to 7.5 g L−1). For higher salinity concentrations (10 to 12.5 g L−1), microcystins were still detected, while significantly lower growth rates were obtained during the exponential growth phase. This suggests that moderate to high salt ranges do not inhibit the microcystins production of P. agardhii at least for several weeks. Finally, the predicted remediation perspectives in a context of environment salinization assumed by environmental policies may be insufficient to eradicate this potential toxic cyanobacteria, especially when this species is already dominant in the waterbodies.

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Appendix 3: Tables of Microcystins and Nodularins

Cited by 97 publications

References 88 publications

High Diversity of Microcystin Chemotypes within a Summer Bloom of the Cyanobacterium Microcystis botrys

High Diversity of Microcystin Chemotypes within a Summer Bloom of the Cyanobacterium Microcystis botrys

Cyanobacterial blooms in freshwaters bodies in a semiarid region, northeastern Brazil: A review

Persistence of microcystin production ofPlanktothrix agardhiiexposed to different salinity concentrations

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