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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Characterization of a microcystin and detection of microcystin synthetase genes from a Brazilian isolate of Nostoc

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Author(s):
Genuario, Diego Bonaldo [1] ; Silva-Stenico, Maria Estela [1] ; Welker, Martin [2] ; Beraldo Moraes, Luiz Alberto [3] ; Fiore, Marli Fatima [1]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Ctr Nucl Energy Agr, BR-13400970 Piracicaba, SP - Brazil
[2] Tech Univ Berlin, FG Umweltmikrobiol, D-10587 Berlin - Germany
[3] Univ Sao Paulo, FFCLRP, Dept Chem, BR-14049 Ribeirao Preto, SP - Brazil
Total Affiliations: 3
Document type: Journal article
Source: Toxicon; v. 55, n. 4, p. 846-854, APR 1 2010.
Web of Science Citations: 18
Abstract

A nostocalean nitrogen-fixing cyanobacterium isolated from an eutrophic freshwater reservoir located in Piracicaba, Sao Paulo, Brazil, was evaluated for the production of hepatotoxic cyclic heptapeptides, microcystins. Morphologically this new cyanobacterium strain appears closest to Nostoc, however, in the phylogenetic analysis of 165 rRNA gene it falls into a highly stable cluster distantly only related to the typical Nostoc cluster. Extracts of Nostoc sp. CENA88 cultured cells, investigated using ELISA assay, gave positive results and the microcystin profile revealed by ESI-Q-TOF/MS/MS analysis confirmed the production of {[}Dha(7)]MCYST-YR. Further, Nostoc sp. CENA88 genomic DNA was analyzed by PCR for sequences of mcyD, mcyE and mcyG genes of microcystin synthetase (mcy) cluster. The result revealed the presence of mcyD, mcyE and mcyG genes with similarities to those from mcy of Nostoc sp. strains 152 and IO-102-I and other cyanobacterial genera. The phylogenetic tree based on concatenated McyG, McyD and McyE amino acids clustered the sequences according to cyanobacterial genera, with exception of the Nostoc sp. CENA88 sequence, which was placed in a clade distantly related from other Nostoc strains, as previously observed also in the 165 rRNA phylogenetic analysis. The present study describes for the first time a Brazilian Nostoc microcystin producer and also the occurrence of demethyl MCYST-YR variant in this genus. The sequenced Nostoc genes involved in the microcystin synthesis can contribute to a better understanding of the toxigenicity and evolution of this cyanotoxin. (C) 2009 Elsevier Ltd. All rights reserved. (AU)

FAPESP's process: 07/06360-8 - Genetic characterization of cyanobacteria isolated from mangrove of São Paulo State based on nifH and cpcBA-IGS nucleotide sequence
Grantee:Diego Bonaldo Genuário
Support Opportunities: Scholarships in Brazil - Master