Draft Genome Sequence of the Symbiotically Competent Cyanobacterium sp. Strain KVJ20.

sp. strain KVJ20 was isolated from the symbiotic organs of the liverwort This cyanobacterium has been shown to have broad symbiotic competence, and bacterial extracts have inhibitory effects on cancer cell lines and microbes. An array of genes for the production of secondary metabolites is present.

Genomic Changes Associated with the Evolutionary Transitions of Nostoc to a Plant Symbiont.

Cyanobacteria belonging to the genus Nostoc comprise free-living strains and also facultative plant symbionts. Symbiotic strains can enter into symbiosis with taxonomically diverse range of host plants. Little is known about genomic changes associated with evolutionary transition of Nostoc from free-living to plant symbiont.

High-Density Cultivation of Terrestrial Nostoc Strains Leads to Reprogramming of Secondary Metabolome.

Terrestrial symbiotic cyanobacteria of the genus exhibit a large potential for the production of bioactive natural products of the nonribosomal peptide, polyketide, and ribosomal peptide classes, and yet most of the biosynthetic gene clusters are silent under conventional cultivation conditions. In the present study, we utilized a high-density cultivation approach recently developed for phototrophic bacteria to rapidly generate biomass of the filamentous bacteria up to a density of 400 g (wet weight)/liter. Unexpectedly, integrated transcriptional and metabolomics studies uncovered a major reprogramming of the secondary metabolome of two strains at high culture density and a governing effect of extracellular signals in this process.

Epiphytic bacterial communities of the alga Fucus vesiculosus in oil-contaminated water areas of the Barents Sea.

Taxonomic compositions of epiphytic bacterial communities in water areas differing in levels of oil pollution were revealed. In total, 82 bacterial genera belonging to 16 classes and 11 phyla were detected. All detected representatives of epiphytic bacterial communities belonged to the phyla Actinobacteria, Bacteroidetes, Planctomycetes, Proteobacteria, Verrucomicrobia, Acidobacteria, Cyanobacteria, Firmicutes, and Fusobacteria and candidate division TM7.

A Genetic and Chemical Perspective on Symbiotic Recruitment of Cyanobacteria of the Genus into the Host Plant L.

Liverwort recruits soil nitrogen-fixing cyanobacteria of genus as symbiotic partners. In this work we compared community composition inside the plants and in the soil around them from two distant locations in Northern Norway. STRR fingerprinting and 16S rDNA phylogeny reconstruction showed a remarkable local diversity among isolates assigned to several clades.

Nostopeptolide plays a governing role during cellular differentiation of the symbiotic cyanobacterium Nostoc punctiforme.

Nostoc punctiforme is a versatile cyanobacterium that can live either independently or in symbiosis with plants from distinct taxa. Chemical cues from plants and N. punctiforme were shown to stimulate or repress, respectively, the differentiation of infectious motile filaments known as hormogonia.

A polyketide interferes with cellular differentiation in the symbiotic cyanobacterium Nostoc punctiforme.

Nostoc punctiforme is a filamentous cyanobacterium capable of forming symbiotic associations with a wide range of plants. The strain exhibits extensive phenotypic characteristics and can differentiate three mutually exclusive cell types: nitrogen-fixing heterocysts, motile hormogonia and spore-like akinetes. Here, we provide evidence for a crucial role of an extracellular metabolite in balancing cellular differentiation.

PHYLOGENETIC PATTERNS AMONG NOSTOC CYANOBIONTS WITHIN BI- AND TRIPARTITE LICHENS OF THE GENUS PANNARIA(1).

Phylogenetic relationships between Nostoc cyanobionts in the lichen genus Pannaria were studied to evaluate their correlation to geography, habitat ecology, and other patterns previously reported. The 16S rRNA gene sequences of a total of 37 samples of 21 Pannaria species from seven countries from the Northern and Southern hemispheres were analyzed and compared with 69 free-living and symbiotic cyanobacterial strains. The sequences from Pannaria were distributed throughout a branch of Nostoc sequences previously called "the Nephroma guild," and within two subgroups from another branch, referred to as the "Peltigera guild," although there was a gradual transition between the two major groups.

Evidence for production of the phytohormone indole-3-acetic acid by cyanobacteria.

The ability of cyanobacteria to produce the phytohormone indole-3-acetic acid (IAA) was demonstrated. A colorimetric (Salkowski) screening of 34 free-living and symbiotically competent cyanobacteria, that represent all morphotypes from the unicellular to the highly differentiated, showed that auxin-like compounds were released by about 38% of the free-living as compared to 83% of the symbiotic isolates. The endogenous accumulation and release of IAA were confirmed immunologically (ELISA) using an anti-IAA antibody on 10 of the Salkowski-positive strains, and the chemical authenticity of IAA was further verified by chemical characterization using gas chromatography-mass spectrometry in Nostoc PCC 9229 (isolated from the angiosperm Gunnera) and in Nostoc 268 (free-living).