Methylation by Ava methylases in Escherichia coli increases the efficiency to transfer of Tn5 in pBR322bla:: Tn5 from E. coli to Anabaena sp. strain PCC 7120 by conjugation. Following conjugation, Tn5 but not pBR322 sequences were found at many different positions in the Anabaena chromosome. This procedure was used to mutagenize, tag, and clone a previously unrecognized gene required for nitrog...

A thiobencarb dose of 3 mg L(-1) reduced the protein content of Anabaena variabilis, whereas it elevated the carbohydrate content. Measurements of Anabaena growth, photosynthetic activity, and respiration rate revealed that the high dose of phosphate (0.53 mM) exerted no additional toxic effect to thiobencarb toxicity. Recovery of Anabaena cells from the inhibitory effect of thiobencarb occurre...

The strengths of several promoters were assessed in the cyanobacterium Anabaena PCC 7120 by fusing them to luxAB, encoding bacterial luciferase. Two promoters, Ptac and PpsbA, with sequences nearly identical to consensus Escherichia coli sigma 70 promoters, gave as high or higher expression than the strong Anabaena promoter, Prbc. Pnpt, the natural promoter driving expression of the kanamycin-r...

In the present study, Synechococcus elongatus and Anabaena, two cyanobacterial species were cultured using different media conditions such as ASN III, modified BG-11, BBM for enrichment of biomass lipid productivity. The experimental result clearly shows that BG 11 was efficient cost-effective medium both isolated Anabaena. influence organic carbon sources on productivity selected studied when ...

The addition of DL-7-azatryptophan (AZAT), a tryptophan analog, to continuous cultures of Anabaena sp. strain CA grown with 10 mM nitrate as the nitrogen source resulted in the differentiation of heterocysts. Analysis of the intracellular amino acid pools of Anabaena sp. strain CA after the addition of AZAT showed a marked decline in the intracellular glutamate pool and a slight increase in the...

The kdpFABC operon of Escherichia coli, coding for the high-affinity K(+) transport system KdpFABC, is transcriptionally regulated by the products of the adjacently located kdpDE genes. The KdpD protein is a membrane-bound sensor kinase consisting of a large N-terminal domain and a C-terminal transmitter domain interconnected by four transmembrane segments (the transmembrane segments together w...

The devBCA operon, encoding subunits of an ATP-binding cassette exporter, is essential for differentiation of N(2)-fixing heterocysts in Anabaena spp. Nitrogen deficiency-dependent transcription of the operon and the use of its transcriptional start point, located 762 (Anabaena variabilis strain ATCC 29413-FD) or 704 (Anabaena sp. strain PCC 7120) bp upstream of the translation start site, were...

Heterotrophic bacteria are commonly found in close associations with photosynthetic cyanobacteria in aquatic ecosystems. Some of these associations can be speciesspecific and mutualistic, resulting in optimal growth and nitrogen-fixing potential for the cyanobacteria. A two-membered culture, consisting of a heterotrophic, epibiotic bacterium attached to an Anabaena sp. was studied in the work r...

Azolla is a genus of free-floating water fern which is widely distributed in aquatic habitats of the tropics and temperate regions. It is one of few vascular plants known to exhibit a symbiotic association with N2fixing blue green algae, Anabaena sp. In view of this, a study was carried out on molecular identification of Anabaena strains isolated from three Azolla species. The selected Azolla s...

Wild-type cyanobacteria of the genus Anabaena are capable of oxygenic photosynthesis, differentiation of cells called heterocysts at semiregular intervals along the cyanobacterial filaments, and aerobic nitrogen fixation by the heterocysts. To foster analysis of the physiological processes characteristic of these cyanobacteria, we have constructed a family of shuttle vectors capable of replicat...