Morphological characteristics and phylogenetic relationship of Anabaena species from Lakes Dianchi and Erhai, China

Abstract

Although Anabaena is one of the most prevalent planktonic freshwater genus in China, there are few taxonomic reports of Anabaena strains by morphology and genetics. In this study, morphological characteristics and phylogenetic relationships of seven Anabaena strains isolated from two plateau lakes, Lakes Dianchi and Erhai, were investigated. Morphological characteristics such as morphology of filament, cellular shapes and sizes, relative position of heterocytes and akinetes, and presence or absence of aerotopes, were described for these seven strains. Phylogenetic relationships were determined by constructing 16S rRNA gene tree using the neighbor-joining algorithm. The seven strains were morphologically identified as three groups, and phylogenetic analysis based on 16S rRNA gene sequences also showed that these seven strains were in three groups. Strains EH-2, EH-3, and EH-4 were in group A belonging to the Anabaena circinalis and A. crassa group, and strains DC-1, DC-2, and EH-1 were in group B and identified as A. flos-aquae. Strain DC-3 without aerotopes was significantly different from the other isolated strains and was determined as A. cylindrica.

Morphological, biochemical and molecular characterization of Anabaena, Aphanizomenon and Nostoc strains (Cyanobacteria, Nostocales) isolated from Portuguese freshwater habitats

“…This so-called polyphasic methodology (including phenotypic, chemotaxonomic and genotypic data) has been increasingly followed by many cyanobacteriologists worldwide, e.g., Rajaniemi et al (2005), Willame et al (2006), Nayak et al (2007), Li et al (2008), Saker et al (2009) andSchleifer (2009). Among the molecular methods, the analysis of the 16S rRNA gene sequences has proved to be a useful tool for exploring phylogenetic relationships among cyanobacteria (Gugger et al, 2002a;Rajaniemi et al, 2005;Willame et al, 2006;Li et al, 2008;Pan et al, 2008;Han et al, 2009;Saker et al, 2009;Komárek, 2010;Zapomělová et al, 2010). However, it is important to highlight that, although the 16S rRNA gene contains variable regions, it is so conserved that it may not always provide a good resolution at the species or intra-species levels in some cyanobacterial groups (Wilmotte, 1994;Lyra et al, 2001;Li & Watanabe, 2004).…”

“…Besides Portuguese rice fields, An. cylindrica was also found in different benthic habitats worldwide (Rajaniemi et al, 2005;Pan et al, 2008). The genus Nostoc is also predominant in rice fields worldwide, as in Portugal (Galhano et al, 2009), and has a beneficial role as a natural biofertilizer in increasing soil fertility (Whitton, 2000).…”

Cyanophages infectingAnabaena circinalisandAnabaena cylindricain a tropical reservoir

“…3 Thus, Anabaena species is believed to contribute to the cyanobacterial blooms in Kranji Reservoir. In this study, we select Anabaena circinalis and Anabaena cylindrica which have different filament morphology 4 to represent toxin producing and non-toxin producing Anabaena species.…”

“…7 The filaments are generally solitary, straight or coiled. 4 In contrast, Anabaena cylindrica trichomes are complexly intertwined with each other and easily form algal mats. 8 Other than vegetative cells, filamentous cyanobacteria have two other prevalent development cell types: heterocysts and A total of six lytic cyanophages have been isolated from Kranji reservoir in Singapore.…”

Moléculas bioativas e filogenia de isolados brasileiros de cianobactérias dos gêneros Dolichospermum, Sphaerospermopsis, Cuspidothrix, Cylindrospermopsis e Microcystis

“…Casos de intoxicações de seres humanos, animais domésticos e selvagens resultantes de florações de cianobactérias e suas toxinas já foram relatados por vários autores (BOURKE et al, 1983;CHORUS et al, 2000;DUY et al, 2000;EDWARDS et al, 1992;GUGGER et al, 2005;SAKER et al, 1999b MOLICA et al, 2005;BECKER et al, 2004;MATTHIENSEN et al, 2000;WERNER et al, 2000;YUNES et al, 2000;LAGOS et al, 1999;AZEVEDO et al, 1994 ZAPOMĚLOVÁ et al, 2010ZAPOMĚLOVÁ et al, , 2009WACKLIN et al, 2009;RAJANIEMI et al, 2005a). Esse rearranjo foi necessário uma vez que a taxonomia de Anabaena, a qual foi elaborada principalmente com base nas características morfológicas, não era consensual, apresentando problemas em níveis genéricos e infragenéricos (PAN et al, 2008;WILLAME et al, 2006;RAJANIEMI et al, 2005b;HOFFMANN, 2004;ITEMAN et al, 2002;RUDI et al, 1998; (SINHA et al, 2012;HOLLAND et al, 2012;HAANDE et al, 2008;BURGER et al, 2007;WIEDNER et al, 2007;KOUZMINOV et al, 2007;HONG et al, 2006). Linhagens de C. raciborskii são potencialmente produtoras de toxina.…”