A novel rhythm of microcystin biosynthesis is described in the cyanobacterium Microcystis panniformis Komarek et al.

Autor(es)

Kujbida, Paula ; Cardozo, Karina Helena Morais ; Carvalho, Valdemir Melechco ; Moura, Ariadne do Nascimento ; Colepicolo, Pio ; Pinto, Ernani ^[6] ; Bittencourt-Oliveira, Maria do Carmo ^[7]

• Tipo de documento: Artigo Científico
• Fonte: Biochemical and Biophysical Research Communications; v. 326, n. 3, p. 687-694, Jan. 2005.
• Área do conhecimento: Ciências Biológicas - Microbiologia
• Assunto(s): Ecossistemas aquáticos Bactérias Microcystis

Resumo

The presence of microcystins (MCY) in the cyanobacteria Microcystis panniformis Komarek et al. is reported for the first time. This strain of cyanobacterium has been isolated from Barra Bonita, an eutrophicated water reservoir in S (a) over tildeo Paulo state, Brazil. The identification of M. panniformis was confirmed by both traditional morphological analysis and the phycocyanin intergenic spacer sequences. MCY-LR and [Asp(3)]-MCY-LR were identified in this strain after HPLC purification and extensive ESI-MS/MS analysis. Their levels in this strain were determined by HPLC and ranged from 0.25 to 2.75 and 0.08 to 0.75 fmol/cell, respectively. Analyzing the levels of MCY-LR and [Asp(3)]-MCY-LR in different times during the light:dark (L:D) cycle, it was found that levels of MCYs per cell were at least threefold as high during the day-phase than during the night-phase. This may be associated to the biological clock since prokaryotic cyanobacteria express robust circadian (daily) rhythms under the control of a timing mechanism that is independent of the cell division cycle. Our findings also showed the same pattern under light:light (L:L) cycle. (AU)

• Processo FAPESP: 03/06443-0 - Algas presentes em florações: isolamento e padronização de métodos analíticos para a quantificação das toxinas
• Beneficiário: Ernani Pinto Junior
• Modalidade de apoio: Auxílio à Pesquisa - Pesquisa em Políticas Públicas
• Processo FAPESP: 03/05773-6 - Filogenia molecular de Microcystis (Cyanobacteria) tóxicas e não-tóxicas de ecossistemas aquáticos tropicais
• Beneficiário: Maria Do Carmo Bittencourt de Oliveira
• Modalidade de apoio: Auxílio à Pesquisa - Regular