کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4546145 1327490 2008 12 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Influence of ultraviolet radiation, copper, and zinc on microcystin content in Microcystis aeruginosa (Cyanobacteria)
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم کشاورزی و بیولوژیک علوم آبزیان
پیش نمایش صفحه اول مقاله
Influence of ultraviolet radiation, copper, and zinc on microcystin content in Microcystis aeruginosa (Cyanobacteria)
چکیده انگلیسی

Cyanobacterial toxin production is allied to some unknown trigger resulting in the production of toxins such as microcystin. We hypothesize that microcystins serve as metal ligands to control bioavailability and toxicity of ambient metals. Since ultraviolet radiation (UVR) promotes photo-oxidation of organic metal ligands and influences trace metal bioavailability, the present study aimed to investigate the influence of UVR, Cu, and Zn on specific growth rates, biomass, photosynthetic capacity, and microcystin content in Microcystis aeruginosa. Two toxigenic strains of Microcystis were cultivated using either Lake Erie filtered water or a chemically defined medium, with realistic concentrations of Cu and Zn combined with natural or artificial UVR exposure. Cu was more toxic than Zn on the basis of free ion concentration of trace metals in synthetic medium, although in Lake Erie water total added Zn (10 nM) or Zn plus Cu (10 nM) had a more detrimental effect on biomass and specific growth rate. Natural UVR delivered at 25% ambient levels caused no decrease on the parameters measured (chlorophyll-a, photosynthetic rate), yet artificial levels of UVR (up to 5.9 μmol UVB photons m−2 s−1) negatively affected biomass and specific growth rate. Cellular levels of microcystin (per unit chlorophyll-a) were concomitant with specific growth rather than being triggered in response either of these stressors (UVR, Zn, and Cu) alone or in combination, in agreement with a purported constitutive production of microcystins.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Harmful Algae - Volume 7, Issue 2, February 2008, Pages 194–205
نویسندگان
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