The taxonomic coherence and phylogenetic relationships of 11 planktonic heterocystous cyanobacterial isolates were examined by investigating two areas of the rRNA operon, the 16S rRNA gene (rrnS) and the internal transcribed spacer (ITS) located between the 16S rRNA and 23S rRNA genes. The rrnS sequences were determined for five strains, including representatives of Anabaena flos-aquae, Aphaniz...

Antifungal and antibacterial activity of some heterocystous cyanobacteria from paddy-fields in the north of Iran was studied. Soil samples were collected from paddy-fields of Gillan, Mazandaran and Golestan Provinces and cyanobacteria were isolated. Supernatants, methanolic and hexane extracts from biomass of 150 strains of cyanobacteria were isolated and screened against six strains of bacteri...

Modern cyanobacteria form a morphologically diversified group. In traditional taxonomy, morphological characters are used to divide them into five subsections [Rippka et al., 1979; Castenholz, 2001]. Cyanobacteria of subsection I (formerly order Chroococcales) and II (Pleurocapsales) are unicellular coccoids. Those of subsections III to V have filamentous forms with varying morphological comple...

In situ nitrogen fixation was investigated in a cyanobacterial mat growing on the bed of rocks of the Muga River, Spain. The filamentous non-heterocystous cyanobacterium Schizothrix dominated the mat, showing nitrogenase activity in the light at similar rates to those found in nearby heterocystous Rivularia colonies. N2 fixation in the light was significantly increased by an inhibitor of PSII a...

BACKGROUND Salinity is known to affect almost half of the world's irrigated lands, especially rice fields. Furthermore, cyanobacteria, one of the critical inhabitants of rice fields have been characterized at molecular level from many different geographical locations. This study, for the first time, has examined the molecular diversity of cyanobacteria inhabiting Indian rice fields which experi...

HetR gene is a key regulator of heterocyst differentiation in filamentous cyanobacteria. It has been previously isolated and characterized from heterocystous cyanobacterium like Anabaena that has intercalary heterocysts and from non-heterocystous cyanobacteria like Trichodesmium and Symploca PCC 8002. This study reports the characterization of hetR gene from Cylindrospermum stagnale A1345, a cy...

We investigated the genotypic diversity of oxygenic and anoxygenic phototrophic microorganisms in microbial mat samples collected from three hot spring localities on the east coast of Greenland. These hot springs harbour unique Arctic microbial ecosystems that have never been studied in detail before. Specific oligonucleotide primers for cyanobacteria, purple sulfur bacteria, green sulfur bacte...

Abstract. Coastal lagoons are important sites for nitrogen (N) removal via sediment burial and denitrification. Blooms of heterocystous cyanobacteria may diminish N retention as dinitrogen (N2) fixation offsets atmospheric losses We measured N2 in the Curonian Lagoon, Europe's largest coastal lagoon, to better understand factors controlling context seasonal changes phytoplankton community compo...