Molecular characterization of planktic cyanobacteria of Anabaena, Aphanizomenon, Microcystis and Planktothrix genera.

Abstract

Toxic and non-toxic cyanobacterial strains from Anabaena, Aphanizomenon, Calothrix, Cylindrospermum, Nostoc, Microcystis, Planktothrix (Oscillatoria agardhii), Oscillatoria and Synechococcus genera were examined by RFLP of PCR-amplified 16S rRNA genes and 16S rRNA gene sequencing. With both methods, high 16S rRNA gene similarity was found among planktic, anatoxin-aproducing Anabaena and non-toxic Aphanizomenon, microcystin-producing and non-toxic Microcystis, and microcystin-producing and non-toxic Planktothrix strains of different geographical origins. The respective sequence similarities were 999-100 %, 942-999 % and 993-100 %. Thus the morphological characteristics (e.g. Anabaena and Aphanizomenon), the physiological (toxicity) characteristics or the geographical origins did not reflect the level of 16S rRNA gene relatedness of the closely related strains studied. In addition, cyanobacterial strains were fingerprinted with repetitive extragenic palindromic ( Abbreviations : ERIC, enterobacterial repetitive intergenic consensus ; LTRR, long tandemly repeated sequence ; ML, maximum-likelihood ; MP, maximum-parsimony ; NJ, neighbour-joining ; REP, repetitive extragenic palindromic ; STRR, short tandemly repeated sequence ; UPGMA, unweighted pairs group method with averages.The GenBank/EMBL accession numbers for the cyanobacterial 16S rRNA gene sequences are AJ133151-AJ133154, AJ133156, AJ133157, AJ133159-AJ133170, AJ133172-AJ133176 and AJ133185 bacteria occur in a wide range of habitats. In eutrophic fresh and brackish waters cyanobacteria form toxic water blooms which have caused human and animal poisonings (Ressom et al., 1994 ; Kuiper-Goodman et al., 1999). The most frequently found toxins in cyanobacterial blooms worldwide are hepatotoxic cyclic peptides, microcystins and nodularins (Sivonen & Jones, 1999). Mass occurrences of cyanobacteria that contain neurotoxins [anatoxin-a, anatoxin-a(S) and saxitoxins] have been found in Australia, Europe and North America (Sivonen & Jones, 1999). Cyanobacteria are a morphologically diverse group of organisms ranging from unicellular to filamentous forms. Traditionally, the classification of cyanobacteria has been based on morphological characters, Asayama et al. (1996) ; 2, Giovannoni et al. (1988) ; 3, Herdman et al. (1979a) ; 4, Herdman et al. (1979b) ; 5, Kenyon et al. (1972) ; 6, Kondo et al. (2000) ; 7, Lachance (1981) ; 8, Leeuwangh et al. (1983) ; 9, Lehtima$ ki et al. (2000) ; 10, Lu et al. (1997) ; 11, Luukkainen et al. (1993) ; 12, Luukkainen et al. (1994) ; 13, Lyra et al. (1997) ; 14, Masephol et al. (1996) ; 15, Mazel et al. (1990) ; 16, Neilan et al. (1995) ; 17, Neilan et al. (1997a) ; 18, Neilan et al. (1997b) ; 19, Neilan et al. (1999) ; 20, Otsuka et al. (1999) ; 21, Rapala et al. (1993) ; 22, Rasmussen & Svenning (1998) ; 23, Rippka & Herdman (1992) ; 24, Rippka et al. (1979) ; 25, Rouhiainen et al. (1995) ; 26, Rudi & Jakobsen (1999) ; 27, Rudi et al. (1997) ; 28, Rudi et al., 1998 ; 29, Sivonen et al. (1989) ; 30, Sivonen et al. (1990) ;...

Polyphyly of true branching cyanobacteria (Stigonematales)

“…Phylogenetic trees were constructed using the neighbour-joining method on Jukes & Cantor (1969) and the Wagner parsimony method of PHYLIP version 3.5c (Felsenstein, 1993). The outgroup was constituted either by distantly related cyanobacteria belonging to Microcystis and Planktothrix (Otsuka et al, 1998;Lyra et al, 2001;Suda et al, 2002) or by the paralogous group of Chroococcidiopsis, as defined by Fewer et al (2002). Bootstrap analysis of 500 resamplings was performed for each consensus tree.…”

Phylogenetic evaluation of cyanobacteria preserved as historic herbarium exsiccata

“…Furthermore, similarity between the 16S rRNA gene sequence of the herbarium Nodularia and Nodularia spumigena strain PCC 73104, the non-toxic type strain for Nodularia spumigena, was 99?7 %. According to Lyra et al (2001Lyra et al ( , 2005 and Moffitt et al (2001), Nodularia spumigena is a planktonic, toxin-producing organism with extremely high 16S rRNA gene sequence similarity values ranging from 98?5-100 %. Both non-toxic strains (PCC 73104 and UTEX B 2092) were isolated from the same ecological niche (alkaline soil) and shared less gene sequence similarity (99?7 %) with the herbarium Nodularia spumigena than with other planktonic Nodularia.…”

Elucidation of the gas vesicle gene clusters in cyanobacteria of the genusArthrospira(Oscillatoriales, Cyanophyta) and correlation with ITS phylogeny

“…Sequence analyses of the 16S rRNA gene established that members of both Arthrospira (Nelissen et al, 1994) and Planktothrix (Lyra et al 2001;Suda et al, 2002) are highly conserved. They also show a relatively low degree of genetic diversity based on several other, more discriminative, molecular markers (Beard et al, 1999;Scheldeman et al, 1999;Baurain et al, 2002;Manen & Falquet, 2002;Christiansen et al, 2008).…”