Variability of microcystins and its synthetase gene cluster in<i>Microcystis</i>and<i>Planktothrix</i>waterblooms in shallow lakes of Hungary

Most cyanobacterial organisms included in the genus Microcystis can produce a wide repertoire of secondary metabolites. In the mid-2010s, summer cyanobacterial blooms of Microcystis sp. occurred regularly in Lake Balaton. During this period, we investigated how the alimentary tract of filter-feeding bigheaded carps could deliver different chemotypes of viable cyanobacteria with specific peptide patterns. Twenty-five Microcystis strains were isolated from pelagic plankton samples (14 samples) and the hindguts of bigheaded carp (11 samples), and three bloom samples were collected from the scums of cyanobacterial blooms. An LC-MS/MS-based untargeted approach was used to analyze peptide patterns, which identified 36 anabaenopeptin, 17 microginin, and 13 microcystin variants. Heat map clustering visualization was used to compare the identified chemotypes. A lack of separation was observed in peptide patterns of Microcystis that originated from hindguts, water samples, and bloom-samples. Except for 13 peptides, all other congeners were detected from the viable and cultivated chemotypes of bigheaded carp. This finding suggests that the alimentary tract of bigheaded carps is not simply an extreme habitat, but may also supply the cyanobacterial strains that represent the pelagic chemotypes.

Section: Discussionmentioning

confidence: 99%

Microcystis Chemotype Diversity in the Alimentary Tract of Bigheaded Carp

Riba

Kiss‐Szikszai

Gonda

et al. 2019

“…Six common cyanobacterial toxins were distributed in Europe. MCs were reported in Finland [203,204], Austria [205], Greece [206], Poland [207], Ireland [208], Portugal [209], Hungary [210], Norway [211], Netherlands [212], Czech [213], Germany [214], Sweden [215], Switzerland [205], Spain [216], Poland [217], the UK [218], Bulgaria [219], Romania [220], France [221,222], Serbia [223], Russia [224,225,226] and Latvia [227]. CYNs were distributed in Ireland [228], Germany [229], France [230], Italy [231], Czech [232], Spain [233], Lebanon [234], Greece [235], Finland [236], Poland [237], Sweden [215], Serbia [238], Portugal [239] and Hungary [240].…”

Section: Distribution Of Cyanotoxinsmentioning

confidence: 99%

The Diversity of Cyanobacterial Toxins on Structural Characterization, Distribution and Identification: A Systematic Review

Liu

Yuan

et al. 2019

136

The widespread distribution of cyanobacteria in the aquatic environment is increasing the risk of water pollution caused by cyanotoxins, which poses a serious threat to human health. However, the structural characterization, distribution and identification techniques of cyanotoxins have not been comprehensively reviewed in previous studies. This paper aims to elaborate the existing information systematically on the diversity of cyanotoxins to identify valuable research avenues. According to the chemical structure, cyanotoxins are mainly classified into cyclic peptides, alkaloids, lipopeptides, nonprotein amino acids and lipoglycans. In terms of global distribution, the amount of cyanotoxins are unbalanced in different areas. The diversity of cyanotoxins is more obviously found in many developed countries than that in undeveloped countries. Moreover, the threat of cyanotoxins has promoted the development of identification and detection technology. Many emerging methods have been developed to detect cyanotoxins in the environment. This communication provides a comprehensive review of the diversity of cyanotoxins, and the detection and identification technology was discussed. This detailed information will be a valuable resource for identifying the various types of cyanotoxins which threaten the environment of different areas. The ability to accurately identify specific cyanotoxins is an obvious and essential aspect of cyanobacterial research.

“…The incident that happened at a hemodialysis center in Caruaru, Brazil, in 1996 proved that MC-contaminated water can lead to hepatic disease or death [ 10 ]. The development of rapid, inexpensive and sensitive monitoring methods [ 11 ] has resulted in the discovery and detection of an increasing diversity of MCs in lakes [ 12 , 13 , 14 , 15 , 16 , 17 ], rivers [ 18 ], reservoirs [ 19 , 20 , 21 ] and ponds [ 22 ] all over the word, suggesting that MC pollution has become a global scientific problem in recent years. To date, more than 90 variants of MCs with variable toxicity have been identified from cyanobacterial blooms and cultures [ 8 ].…”

Section: Introductionmentioning

confidence: 99%

Spatiotemporal Dynamics of Microcystin Variants and Relationships with Environmental Parameters in Lake Taihu, China

Xue

Steinman

et al. 2015

Excessive anthropogenically-caused nutrient loading from both external and internal sources has promoted the growth of cyanobacteria in Lake Taihu from 2005 to 2014, suggesting increased production and release of cyanotoxins. In order to explain the spatial distribution and temporal variation of microcystins (MCs), the intracellular concentrations of MCs (MC-LR, -RR and -YR, L, R and Y are abbreviations of leucine, arginine and tyrosine) were monitored monthly from July 2013 to June 2014. Three MC variants are present simultaneously in Lake Taihu; the MC-LR and -RR variants were dominant (accounting for 40% and 39% of the total), followed by MC-YR (21%). However, MC-YR accounted for a higher proportion in colder months, especially in March. The highest concentrations of intracellular MCs were found in July and October when cyanobacteria cell density also reached the maximum. The average concentrations of MC-LR, -RR and -YR in July were 4.69, 4.23 and 2.01 μg/L, respectively. In terms of the entire lake, toxin concentrations in northern parts were significantly higher than the eastern part in summer, when MC concentrations were several times higher than the guideline value by WHO throughout much of Lake Taihu. Results from correlation and redundancy analysis (RDA) showed that total MCs, including all variants, were strongly and positively correlated with cyanobacteria cell density, water temperature, total phosphorus (TP) and pH, whereas each variant had different correlation coefficients with each of the considered environmental variables. MC-RR showed a stronger relationship with temperature, in contrast to MC-YR and -LR. Dissolved inorganic carbon (DIC) showed a negative relationship with each variant, suggesting that rising DIC concentrations may inhibit cyanobacterial growth and thereby reduce MC production in the future.