The taxonomy of cyanobacteria has been substantially modified in the last few decades, particularly after application of modern ultra structural and molecular methods. The present research, therefore, aimed to investigate, through a polyphasic approach, the differences in morphological and genotypic features of two cyanobacteria strains isolated from different agricultural and freshwaters areas...

The genes encoding the RNA subunit of ribonuclease P from the unicellular cyanobacterium Synechocystis sp. PCC 6803, and from the heterocyst-forming strains Anabaena sp. PCC 7120 and Calothrix sp. PCC 7601 were cloned using the homologous gene from Anacystis nidulans (Synechococcus sp. PCC 6301) as a probe. The genes and the flanking regions were sequenced. The genes from Anabaena and Calothrix...

Cyanobacteria are considered a promising source for new ‎pharmaceutical lead compounds and a large number of chemically diverse and ‎bioactive metabolites have been obtained from cyanobacteria. Despite of ‎several worldwide studies on prevalence of NRPSs and PKSs among the ‎cyanobacteria, none of them included Iranian cyanobacteria of Kermanshah ‎province. Therefore, the aim of this study was t...

We characterized three distinct families of repeated sequences in the genome of the cyanobacterium Calothrix sp. strain PCC 7601. These repeated sequences were present at a level of about 100 copies per Calothrix genome and consisted of tandemly amplified heptanucleotides. These elements were named short tandemly repeated repetitive (STRR) sequences. We used the three different Calothrix STRR s...

Microorganisms in the rhizosphere mediate the cycling of nutrients, their enhanced mobilisation and facilitate their uptake, leading to increased root growth, biomass and yield of plants. We examined the promise of beneficial cyanobacteria and eubacteria as microbial inoculants, applied singly or in combination as consortia or biofilms, to improve growth and yields of okra. Interrelationships a...

Glutamine synthetases (GSs) from two cyanobacteria, one unicellular (Synechocystis sp. strain PCC 6803) and the other filamentous (Calothrix sp. strain PCC 7601 [Fremyella diplosiphon]), were purified to homogeneity. The biosynthetic activities of both enzymes were strongly inhibited by ADP, indicating that the energy charge of the cell might regulate the GS activity. Both cyanobacteria exhibit...

Cyanobacteria colonizing the feather moss Pleurozium schreberi were isolated from moss samples collected in northern Sweden and subjected to physiological and molecular characterization. Morphological studies of isolated and moss-associated cyanobacteria were carried out by light microscopy. Molecular tools were used for cyanobacteria identification, and a reconstitution experiment of the assoc...

The ntcA gene from Synechococcus sp. strain PCC 7942 encodes a regulatory protein which is required for the expression of all of the genes known to be subject to repression by ammonium in that cyanobacterium. Homologs to ntcA have now been cloned by hybridization from the cyanobacteria Synechocystis sp. strain PCC 6803 and Anabaena sp. strain PCC 7120. Sequence analysis has shown that these ntc...

In cyanobacteria, phycobilisomes are regularly arrayed on the surface of the photosynthetic membranes, and their role is to funnel light energy to the underlying photosystem II reaction center. A model has recently been proposed that ascribes to the so-called LCM, a central role in the building up of the phycobilisome, in addition to its role of terminal energy acceptor (Capuano, V., Braux, A.-...