High Levels of Anabaenopeptins Detected in a Cyanobacteria Bloom from N.E. Spanish Sau-Susqueda-El Pasteral Reservoirs System by LC–HRMS

Abstract

The appearance of a bloom of cyanobacteria in the Sau-Susqueda-El Pasteral system (River Ter, NE Spain) in the autumn of 2015 has been the most recent episode of extensive bloom detected in Catalonia. This system is devoted mainly to urban supply, regulation of the river, irrigation and production of hydroelectric energy. In fact, it is one of the main supply systems for the metropolitan area of cities such as Barcelona and Girona. An assessment and management plan was implemented in order to minimize the risk associated to cyanobacteria. The reservoir was confined and periodic sampling was carried out. Low and high toxicity was detected by cell bioassays with human cell lines. Additionally, analysis studies were performed by enzyme-linked immunosorbent assay (ELISA) and liquid chromatography–high resolution mass spectrometry (LC–HRMS). A microcystin target analysis and suspect screening of microcystins, nodularins, cylindrosperpmopsin and related cyanobacterial peptides by LC–HRMS were applied. The results for the analysis of microcystins were negative (<0.3 μg/L) in all the surface samples. Only traces of microcystin-LR, -RR and -dmRR were detected by LC–HRMS in a few ng/L from both fractions, aqueous and sestonic. In contrast, different anabaenopeptins and oscillamide Y at unusually high concentrations (µg-mg/L) were observed. To our knowledge, no previous studies have detected these bioactive peptides at such high levels. The reliable identification of these cyanobacterial peptides was achieved by HRMS. Although recently these peptides are detected frequently worldwide, these bioactive compounds have received little attention. Therefore, more studies on these substances are recommended, especially on their toxicity, health risk and presence in water resources.

Anabaenopeptins: What We Know So Far

“…A total of 45, 29, and 12 cyanobacteria strains from freshwater, marine and terrestrial environment have been analyzed for AP production, respectively. As seen in Table 2 and according to the literature [ 34 , 40 , 41 , 53 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 , 85 ], marine strains produced a total of 50 different variants of APs, in comparison to 43 and 34 variants from freshwater, and terrestrial strains, respectively ( Figure 7 ). Thus, marine cyanobacteria demonstrate to produce a higher number of distinct APs variants in comparison to the remaining strains from different sources.…”

Anabaenopeptins from Cyanobacteria in Freshwater Bodies of Greece

“…Anabaenopeptins (APs) are cyanobacterial metabolites with a cyclic peptide structure [1]. The presence of APs has been reported in freshwater [2][3][4][5][6] and marine cyanobacterial blooms [7][8][9], as well as in terrestrial environments, including the leaves of plants in a coastal forest [10] and the terrestrial mat in a bamboo forest [11]. APs are produced by freshwater, marine and terrestrial cyanobacteria [12] mainly belonging to the genera Planktothrix [13,14], Anabaena [15][16][17][18], Microcystis [19][20][21][22][23] and Nostoc [24,25].…”

“…Furthermore, APs could possibly control cyanobacterial population density as the presence of APs (i.e., Anabaenopeptin B and Anabaenopeptin F) has been correlated with the triggering of cell lysis that ends up in the collapse of cyanobacterial blooms [72]. The occurrence of APs in cyanobacterial blooms and cultured strains from freshwater bodies has been reported more frequently during recent years in several countries worldwide, including Japan [2,[26][27][28], Germany [3,13,19,20], Finland [16,18], Norway [73,74], Poland [47,75,76], Slovenia [33], Czech Republic [22,77], Austria [34], Hungary [23], Switzerland [78], Spain [4,6,79], Portugal [37,38], Italy [80][81][82][83][84], France [85,86], United Kingdom [85,87], Turkey [44], Israel [21,39,88], Brazil [89], Canada [59,86,90], USA [64,…”

The 6th Iberian and 2nd Ibero-American Cyanotoxin Congress CIC2019

“…Some fairly rare toxins may abound locally and may represent important hazards that affect people, animals, and even crops. Anabaenopeptins (A, B, C, and F) and Oscilamide Y were detected at unusually high concentrations in a reservoir system in NE Spain [ 11 ] and [D-Leu 1 ]MC-LR is more frequent than MC-LR in some South American countries [ 12 ]. The detection of some of these compounds may pose a challenge, and Flores and Caixach [ 11 ] recommend taking a suspect screening approach based on High-Resolution Mass Spectrometry (HRMS) for the cyanobacterial peptides that are not often monitored by target strategies.…”

“…Anabaenopeptins (A, B, C, and F) and Oscilamide Y were detected at unusually high concentrations in a reservoir system in NE Spain [ 11 ] and [D-Leu 1 ]MC-LR is more frequent than MC-LR in some South American countries [ 12 ]. The detection of some of these compounds may pose a challenge, and Flores and Caixach [ 11 ] recommend taking a suspect screening approach based on High-Resolution Mass Spectrometry (HRMS) for the cyanobacterial peptides that are not often monitored by target strategies. [D-Leu1] MC-LR is frequently reported in water bodies throughout America and shows clear toxic potency differences with MC-LR, with greater phosphatase activity inhibition in both animal and plant models.…”