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Are known cyanotoxins involved in the toxicity of picoplanktonic and filamentous North Atlantic marine cyanobacteria?

Frazão B, Martins R, Vasconcelos V - Mar Drugs (2010)

Bottom Line: Strains were toxic to the brine shrimp A. salina nauplii with aqueous extracts being more toxic than the organic ones.Although mass spectrometry analysis did not reveal the production of microcystins or other known toxic peptides, a positive result for the presence of mcyE gene was found in one Leptolyngbya strain and one Oscillatoria strain.The extensive brine shrimp mortality points to the involvement of other unknown toxins, and the presence of a fragment of genes involved in the cyanotoxin production highlight the potential risk of cyanobacteria occurrence on the Atlantic coast.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Porto, Portugal. bmfrazao@gmail.com

ABSTRACT
Eight marine cyanobacteria strains of the genera Cyanobium, Leptolyngbya, Oscillatoria, Phormidium, and Synechococcus were isolated from rocky beaches along the Atlantic Portuguese central coast and tested for ecotoxicity. Strains were identified by morphological characteristics and by the amplification and sequentiation of the 16S rDNA. Bioactivity of dichloromethane, methanol and aqueous extracts was assessed by the Artemia salina bioassay. Peptide toxin production was screened by matrix assisted laser desorption/ionization time of flight mass spectrometry. Molecular analysis of the genes involved in the production of known cyanotoxins such as microcystins, nodularins and cylindrospermopsin was also performed. Strains were toxic to the brine shrimp A. salina nauplii with aqueous extracts being more toxic than the organic ones. Although mass spectrometry analysis did not reveal the production of microcystins or other known toxic peptides, a positive result for the presence of mcyE gene was found in one Leptolyngbya strain and one Oscillatoria strain. The extensive brine shrimp mortality points to the involvement of other unknown toxins, and the presence of a fragment of genes involved in the cyanotoxin production highlight the potential risk of cyanobacteria occurrence on the Atlantic coast.

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PCR products amplified from strains LEGE 06010 and LEGE 06018, Leptolyngbya sp. and Oscillatoria sp, respectively, with HEPF/HEPR primers. (A) Lane 1: strain LEGE 06025 (data not shown); Lane 2: strain LEGE 06010; M-1Kb; (B) Lanes 1 and 2: strain LEGE 06025 (data not shown); Lane 3: strain LEGE 06018. M: Marker; P: Positive control (M6 strain), N: Negative control.
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f1-marinedrugs-08-01908: PCR products amplified from strains LEGE 06010 and LEGE 06018, Leptolyngbya sp. and Oscillatoria sp, respectively, with HEPF/HEPR primers. (A) Lane 1: strain LEGE 06025 (data not shown); Lane 2: strain LEGE 06010; M-1Kb; (B) Lanes 1 and 2: strain LEGE 06025 (data not shown); Lane 3: strain LEGE 06018. M: Marker; P: Positive control (M6 strain), N: Negative control.

Mentions: For most of the strains, no amplification of any of the toxin genes was obtained. Nevertheless, 439 and 431 base pair (bp) fragments were obtained with the HEP primers reaction for strains LEGE 06010 and LEGE 06018, Leptolyngbya sp. and Oscillatoria sp. respectively (Figure 1). In order to confirm the identity of the amplified fragments, the PCR products were sequenced. The sequences were compared with sequences from the GenBank and we found 99% similarity with the mcyE of the microcystin synthetase gene cluster from a Microcystis sp. CYN06 strain (Table 3).


Are known cyanotoxins involved in the toxicity of picoplanktonic and filamentous North Atlantic marine cyanobacteria?

Frazão B, Martins R, Vasconcelos V - Mar Drugs (2010)

PCR products amplified from strains LEGE 06010 and LEGE 06018, Leptolyngbya sp. and Oscillatoria sp, respectively, with HEPF/HEPR primers. (A) Lane 1: strain LEGE 06025 (data not shown); Lane 2: strain LEGE 06010; M-1Kb; (B) Lanes 1 and 2: strain LEGE 06025 (data not shown); Lane 3: strain LEGE 06018. M: Marker; P: Positive control (M6 strain), N: Negative control.
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC2901829&req=5

f1-marinedrugs-08-01908: PCR products amplified from strains LEGE 06010 and LEGE 06018, Leptolyngbya sp. and Oscillatoria sp, respectively, with HEPF/HEPR primers. (A) Lane 1: strain LEGE 06025 (data not shown); Lane 2: strain LEGE 06010; M-1Kb; (B) Lanes 1 and 2: strain LEGE 06025 (data not shown); Lane 3: strain LEGE 06018. M: Marker; P: Positive control (M6 strain), N: Negative control.
Mentions: For most of the strains, no amplification of any of the toxin genes was obtained. Nevertheless, 439 and 431 base pair (bp) fragments were obtained with the HEP primers reaction for strains LEGE 06010 and LEGE 06018, Leptolyngbya sp. and Oscillatoria sp. respectively (Figure 1). In order to confirm the identity of the amplified fragments, the PCR products were sequenced. The sequences were compared with sequences from the GenBank and we found 99% similarity with the mcyE of the microcystin synthetase gene cluster from a Microcystis sp. CYN06 strain (Table 3).

Bottom Line: Strains were toxic to the brine shrimp A. salina nauplii with aqueous extracts being more toxic than the organic ones.Although mass spectrometry analysis did not reveal the production of microcystins or other known toxic peptides, a positive result for the presence of mcyE gene was found in one Leptolyngbya strain and one Oscillatoria strain.The extensive brine shrimp mortality points to the involvement of other unknown toxins, and the presence of a fragment of genes involved in the cyanotoxin production highlight the potential risk of cyanobacteria occurrence on the Atlantic coast.

View Article: PubMed Central - PubMed

Affiliation: Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Porto, Portugal. bmfrazao@gmail.com

ABSTRACT
Eight marine cyanobacteria strains of the genera Cyanobium, Leptolyngbya, Oscillatoria, Phormidium, and Synechococcus were isolated from rocky beaches along the Atlantic Portuguese central coast and tested for ecotoxicity. Strains were identified by morphological characteristics and by the amplification and sequentiation of the 16S rDNA. Bioactivity of dichloromethane, methanol and aqueous extracts was assessed by the Artemia salina bioassay. Peptide toxin production was screened by matrix assisted laser desorption/ionization time of flight mass spectrometry. Molecular analysis of the genes involved in the production of known cyanotoxins such as microcystins, nodularins and cylindrospermopsin was also performed. Strains were toxic to the brine shrimp A. salina nauplii with aqueous extracts being more toxic than the organic ones. Although mass spectrometry analysis did not reveal the production of microcystins or other known toxic peptides, a positive result for the presence of mcyE gene was found in one Leptolyngbya strain and one Oscillatoria strain. The extensive brine shrimp mortality points to the involvement of other unknown toxins, and the presence of a fragment of genes involved in the cyanotoxin production highlight the potential risk of cyanobacteria occurrence on the Atlantic coast.

Show MeSH
Related in: MedlinePlus