title: Production of anatoxin-a by cyanobacterial strains isolated from Portuguese fresh water systems.
abstract: The occurrence of anatoxin-a in several freshwater systems in Portugal and its production by Portuguese cyanobacterial strains, after cultivation in laboratory, were studied. Surface water samples from 9 water bodies, for recreational and human consumption usage, were surveyed for anatoxin-a presence and for obtaining cultures of pure cyanobacterial strains. Anatoxin-a analysis was performed by high performance liquid chromatography (HPLC) with fluorescence detection (FLD) followed by Mass Spectrometry (MS) confirmation. No anatoxin-a was detected in all the natural water samples (limit of detection (LOD) = 25 ng l(-1)) but among the 22 isolated cyanobacterial strains, 13 could produce anatoxin-a in laboratory conditions (LOD = 3 ng g(-1) dw). This proportion of anatoxin-a producing strains (59.1%) in laboratory is discussed considering the hypothesis that anatoxin-a is a more frequent metabolite in cyanobacteria than it was thought before and making its occurrence in Portuguese freshwaters almost certain. Therefore, health and ecological risks caused by anatoxin-a in Portugal, should be seriously considered.
authors.affiliation: Interdisciplinary Centre of Marine and Environmental Research (CIIMAR/CIMAR-U.P.), Rua dos Bragas, 289, 4050-123, Porto, Portugal. joanaosswald@ciimar.up.pt
authors.forename: Joana
authors.initials: J
authors.lastname: Osswald
authors.forename: Sandra
authors.initials: S
authors.lastname: Rellán
authors.forename: Ana
authors.initials: A
authors.lastname: Gago-Martinez
authors.forename: Vítor
authors.initials: V
authors.lastname: Vasconcelos
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D000458:Cyanobacteria / Q000378:metabolism*; D000087522:Cyanobacteria Toxins; D004784:Environmental Monitoring / Q000379:methods; D005618:Fresh Water / Q000737:chemistry; D013058:Mass Spectrometry; D011174:Portugal; D014326:Tropanes / Q000032:analysis / Q000737:chemistry*; D014873:Water Pollutants / Q000032:analysis / Q000737:chemistry*; D014881:Water Supply / Q000032:analysis* / Q000592:standards
chemical_list: D000087522:Cyanobacteria Toxins; D014326:Tropanes; D014873:Water Pollutants; C509783:anatoxin a