Anabaena variabilis grows heterotrophically using fructose, while the close relative Anabaena sp. strain PCC 7120 does not. Introduction of a cluster of genes encoding a putative ABC transporter, herein named frtRABC, into Anabaena sp. strain PCC 7120 on a replicating plasmid allowed that strain to grow in the dark using fructose, indicating that these genes are necessary and sufficient for het...

A 10-kb DNA region of the cyanobacterium Anabaena variabilis ATCC 29413 containing the structural genes of the uptake hydrogenase (hupSL) was cloned and sequenced. In contrast to the hupL gene of Anabaena sp. strain PCC 7120, which is interrupted by a 10.5-kb DNA fragment in vegetative cells, there is no programmed rearrangement within the hupL gene during the heterocyst differentiation of A. v...

We have determined that the type II restriction enzyme . Ava II , isolated from Anabaena variabilis, recognizes and cuts the sequence 5' G-1GTCC 3' 3 CCAG+G 5' The eight Ava II sites of pBR322 have been mapped, as well as a unique site for Ava

Cyanobacterial secondary metabolites have a diverse antagonistic activity that lead to disintegration of microbial growth. The study was conducted to evaluate the antifungal property possessed by cyanobacteriaAnabaena variabilis in retarding the growth of plant pathogenic fungal species. It was observed that the extracts prepared from Anabaena variabilis were capable of diminishing the growth a...

In vitro fatty acid synthesis was examined in crude cell extracts, soluble fractions, and 80% (NH(4))(2)SO(4) fractions from Anabaena variabilis M3. Fatty acid synthesis was absolutely dependent upon acyl carrier protein and required NADPH and NADH. Moreover, fatty acid synthesis and elongation occurred in the cytoplasm of the cell. The major fatty acid products were palmitic acid (16:0) and st...

Three strains of cyanobacteria (Anabaena PCC7120, A. variabilis and Nostoc commune), all belonging to the family Nostocaceae, were found to be capable of modulating the production and chemical composition of extracellular polysaccharides (EPS) in response to carbon and nitrogen availability as well as pH. While the carbohydrate compositions of the glycans produced by the different organisms wer...

The nitrogenase gene cluster in cyanobacteria has been thought to comprise multiple operons; however, in Anabaena variabilis, the promoter for the first gene in the cluster, nifB1, appeared to be the primary promoter for the entire nif cluster. The structural genes nifHDK1 were the most abundant transcripts; however, their abundance was not controlled by an independent nifH1 promoter, but rathe...

The organisms of a bluish-green layer beneath the shards of a gypsum rock were characterized by molecular techniques. The cyanobacterial consortium consisted almost exclusively of Chroococcidiopsis spp. The organisms of the shards expressed nitrogenase activity (C2H2 reduction) aerobically and in light. After a prolonged period of drought at the rock, the cells were inactive, but they resumed n...