The diversity of nitrogenase genes in a marine cyanobacterial mat was investigated through amplification of a fragment of nifH, which encodes the Fe protein of the nitrogenase complex. The amplified nifH products were characterized by DNA sequencing and were compared with the sequences of nitrogenase genes from cultivated organisms. Phylogenetic analysis showed that similar organisms clustered ...

Bloom-forming freshwater cyanobacterial genera pose a major ecological problem due to their ability to produce toxins and other bioactive compounds, which can have important implications in illnesses of humans and livestock. Cyanobacteria such as Microcystis, Anabaena, Oscillatoria, Phormidium, and Aphanizomenon species producing microcystins and anatoxin-a have been predominantly documented fr...

Two cases of primary plastid endosymbiosis are known. The first occurred ca. 1.6 billion years ago and putatively gave rise to the canonical plastid in algae and plants. The second is restricted to a genus of rhizarian amoebae that includes Paulinella chromatophora. Photosynthetic Paulinella species gained their plastid from an α-cyanobacterial source and are sister to plastid-lacking phagotrop...

Cyanobacteria may possess several enzymes that are directly involved in dihydrogen metabolism: nitrogenase(s) catalyzing the production of hydrogen concomitantly with the reduction of dinitrogen to ammonia, an uptake hydrogenase (encoded by hupSL) catalyzing the consumption of hydrogen produced by the nitrogenase, and a bidirectional hydrogenase (encoded by hoxFUYH) which has the capacity to bo...

Features of cyanobacteria are introduced for non-specialists by highlighting topics in the various chapters. Aspects where much more is known now than a decade ago are pointed out, such as the importance of cyanobacterial nitrogen fi xation in the oceans. This is followed by an account of the recent molecular studies most relevant for ecologists, especially topics not mentioned elsewhere in the...

Cyanobacteria from exotic niches represent a rich resource of a wide array of unique bioactive compounds that are largely under explored, and proving to be potent source of anticancer drugs. A filamentous non-heterocystous isolate was identified by light microscopy and molecular methods using 23S rDNA as a marker was found to belong to Plectonema genus of Cyanobacteria. Organic extract of diffe...

In this study, the biomass and exopolysaccharides (EPS) production in co-cultures of microalgae/cyanobacteria and macromycetes was evaluated as a technology for producing new polysaccharides for medical and/or industrial application. Based on biomass and EPS productivity of monocultures, two algae and two fungi were selected and cultured in different co-culture arrangements. The hydrosoluble EP...

A bacterial strain, isolated from a cyanobacterial culture, was identified as Pseudomonas sp. strain X40. Under iron-limiting conditions, the Pseudomonas sp. produced aerobactin, a dihydroxamate siderophore previously found only in the family Enterobacteriaceae. Aerobactin was identified by electrophoretic mobility, spectrophotometric titration, proton nuclear magnetic resonance spectroscopy, m...

Purpose: To evaluate the anti-cancer properties of the cyanobacterial extract of Oscillatoria terebriformis Methods: The extract was tested in Human lung cancer cell lines and examined for its effect on cell viability, nuclear morphology and sub-G1 formation. Cell viability was determined by micro culture tetrazolium technique (MTT), nuclear morphology investigated using 4’-6-diamidino-2-phenyl...

While multiple phylogenetic markers have been used in the culture-independent study of microcystin-producing cyanobacteria, in only a few instances have multiple markers been studied within individual cells, and in all cases these studies have been conducted with cultured isolates. Here, we isolate and evaluate large DNA fragments (>6 kb) encompassing two genes involved in microcystin biosynthe...