Cyanobacteria produce a wide range of metabolites of interest for industrial or medical use. The cultivation of freshwater Nostoc cf. linckia yielded 5.4 g/L of a crude exopolysaccharide (cEPS) with a molecular weight of 1.31 × 105 g/mol. Ion-exchange chromatography of cEPS yielded two dominant fractions, EPS-1 and EPS-2, differing in molecular weight. The lower molecular weight fraction (EPS-1) was subjected to structural studies. Results of chemical and spectroscopic analyses showed that three of the four dominant sugars, glucose, galactose and xylose are 1,4-linked in the backbone in the following order: [→4)-β-D-Xylp-(1 → 4)-β-D-Glcp-(1 → 4)-α-D-Galp-(1 → 4)-β-D-Glcp-(1→]n. Terminal mannose residues were identified as side chains linked at C3 of every third backbone xylose and every second glucose is branched at C6 by 3-O-lactyl-β-D-glucuronic acid (nosturonic acid). Antioxidant properties of EPS were tested using two in vitro methods. Both assays showed that the cEPS was more active than purified EPS-1 and EPS-2 fractions and deproteinized EPS.
- MeSH
- Antioxidants chemistry MeSH
- Polysaccharides, Bacterial analysis chemistry MeSH
- Galactose chemistry MeSH
- Glucose chemistry MeSH
- Glucuronic Acid chemistry MeSH
- Magnetic Resonance Spectroscopy methods MeSH
- Molecular Structure MeSH
- Molecular Weight MeSH
- Nostoc chemistry MeSH
- Xylose chemistry MeSH
- Publication type
- Journal Article MeSH
Complex structure of cyanobacterium Nostoc sp. exopolysaccharide (EPS), with apparent molecular weight 214 × 103 g/mol, can be deduced from its composition. Chemical and NMR analyses found four dominant sugar monomers, namely (1 → 4)-linked α-l-arabinopyranose, β-d-glucopyranose, β-d-xylopyranose and (1 → 3)-linked β-d-mannopyranose, two different uronic acids and a lactyl group, with (1 → 4,6)-linked β-d-glucopyranose as the only branch point suggest a complex structure of this polymer. The dominant uronic acid is α-linked, but it remained unidentified. β-d-Glucuronic acid was present in lower amount. Their position as well as that of lactyl remained undetermined too. Different doses of orally administered EPS in guinea pigs evoked a significant decrease in cough effort and a decrease in airway reactivity. The antitussive efficacy and bronchodilator effect of higher doses of EPS were found to be similar to that of the antitussive drug codeine and the antiasthmatic salbutamol. Without significant cytotoxicity on the RAW 264.7 cells, EPS stimulated the macrophage cells to produce pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and prostaglandins (PGs) and nitric oxide (NO) via induction of COX-2 and iNOS expression, respectively, suggesting that this biopolymer potentiates an early innate immune response and can therefore be used as a new immune modulator.
- MeSH
- Albuterol pharmacology MeSH
- Polysaccharides, Bacterial chemistry pharmacology MeSH
- Biopolymers chemistry MeSH
- Bronchodilator Agents pharmacology MeSH
- Cell Line MeSH
- Cytokines metabolism MeSH
- Interleukin-6 metabolism MeSH
- Cough drug therapy MeSH
- Codeine pharmacology MeSH
- Glucuronic Acid chemistry MeSH
- Uronic Acids chemistry MeSH
- Macrophages drug effects metabolism MeSH
- Guinea Pigs MeSH
- Mice MeSH
- Nostoc metabolism MeSH
- Nitric Oxide metabolism MeSH
- RAW 264.7 Cells MeSH
- Cyanobacteria metabolism MeSH
- Tumor Necrosis Factor-alpha metabolism MeSH
- Animals MeSH
- Check Tag
- Guinea Pigs MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Cyanobacterial strain ARC8 was isolated from seepage coming into the river Dračice, Františkov, Czech Republic, and was characterized using a polyphasic approach. Strain ARC8 showed a typical Nostoc-like morphology and in-depth morphological characterization indicated that it is a member of the genus Nostoc. Furthermore, in the 16S rRNA gene phylogeny inferred using Bayesian inference, maximum likelihood and neighbour joining methods, strain ARC8 clustered within the Nostoc sensu stricto clade. The phylogenetic distance and the positioning of strain ARC8 also indicated that it is a member of the genus Nostoc. Furthermore, the rbcL gene phylogeny along with the 16S-23S ITS secondary structure analysis also supported the findings from the 16S rRNA gene tree. In accordance with the International Code of Nomenclature for Algae, Fungi and Plants we describe a novel species of Nostoc with the name Nostoc neudorfense sp. nov.
- MeSH
- Bayes Theorem MeSH
- DNA, Bacterial genetics MeSH
- Phylogeny * MeSH
- Nostoc classification isolation & purification MeSH
- Rivers microbiology MeSH
- RNA, Ribosomal, 16S genetics MeSH
- Sequence Analysis, DNA MeSH
- Bacterial Typing Techniques MeSH
- Base Composition MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
Superabsorbent polymers (SAPs) are most often used in hygienic goods or in the agricultural sector but the range of their application is much broader, including the utilization in advanced building materials. Although SAPs were studied widely during the last decades, the data related to the interactions between the natural environment and various organisms occurring on their surface are still lacking. In addition, SAPs can create a variable gel-forming matter in the presence of water but standard ecotoxicological bioassays are mostly not suitable for testing such type of materials. In this study, the SAPs potential for reducing/supporting unwanted indoor microorganism settlement was analyzed by biological methods under controlled laboratory conditions. Three commonly used SAPs (Cabloc CT, Creasorb SIS, Hydropam) were exposed to selected organisms representing green algae (Hematococcus pluvialis), cyanobacteria (Nostoc sp.), yeasts (Saccharomyces cerevisiae), wood-destroying fungi (Gleophyllium trabeum), and aerial molds. The obtained results indicated that Hydropam provided favorable conditions for Hematococcus pluvialis, Nostoc sp., and Saccharomyces cerevisiae. All three tested SAPs inhibited, both with and without nutrient addition, the growth of Gleophyllium trabeum and aerial molds.
- MeSH
- Acrylamide chemistry MeSH
- Chlorophyta growth & development MeSH
- Construction Materials microbiology MeSH
- Humans MeSH
- Nostoc growth & development isolation & purification MeSH
- Polymers chemistry MeSH
- Saccharomyces cerevisiae growth & development isolation & purification MeSH
- Water chemistry MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
In a controlled growth experiment we found that the cyanobacterium Nostoc punctiforme has a bulk cell 26Mg/24Mg ratio (expressed as δ26Mg) that is -0.27‰ lower than the growth solution at a pH of ca. 5.9. This contrasts with a recently published δ26Mg value that was 0.65‰ higher than growth solution for the black fungus Knufia petricola at similar laboratory conditions, interpreted to reflect loss of 24Mg during cell growth. By a mass balance model constrained by δ26Mg in chlorophyll extract we inferred the δ26 Mg value of the main Mg compartments in a cyanobacteria cell: free cytosolic Mg (-2.64‰), chlorophyll (1.85‰), and the nonchlorophyll-bonded Mg compartments like ATP and ribosomes (-0.64‰). The lower δ26Mg found in Nostoc punctiforme would thus result from the absence of significant Mg efflux during cell growth in combination with either (a) discrimination against 26Mg during uptake by desolvation of Mg or transport across protein channels or (b) discrimination against 24Mg in the membrane transporter during efflux. The model predicts the preferential incorporation of 26Mg in cells and plant organs low in Mg and the absence of isotope fractionation in those high in Mg, corroborated by a compilation of Mg isotope ratios from fungi, bacteria, and higher plants.
- MeSH
- Chemical Fractionation MeSH
- Magnesium * MeSH
- Isotopes MeSH
- Nostoc * MeSH
- Plants MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Benthic cyanobacteria recognized as producers of natural products, including cyanotoxins, have been neglected for systematic toxicological studies. Thus, we have performed a broad study investigating cyanotoxin potential of 311 non-planktic nostocacean representatives combining molecular and chemical analyses. Out of these, a single strain Nostoc sp. Treb K1/5, was identified as a new microcystin producer. Microcystins [Asp3]MC-YR, [Asp3]MC-FR, [Asp3]MC-HtyR and Ala-Leu/Ile-Asp-Arg-Adda-Glu-Mdha are reported for the first time from the genus Nostoc. All the studied strains were also analyzed for the occurrence of nodularins, cylindrospermopsin and (homo)anatoxin-a, yet no novel producer has been discovered. Our findings indicate rare occurrence of the common cyanotoxins in non-planktic nostocaceae which is in contrast with frequent reports of cyanotoxin producers among phylogenetically closely related planktic cyanobacteria.
- MeSH
- Phylogeny MeSH
- Microcystins chemistry metabolism MeSH
- Nostoc genetics metabolism MeSH
- Publication type
- Journal Article MeSH
Cytokinins are an important group of plant hormones that are also found in other organisms, including cyanobacteria. While various aspects of cytokinin function and metabolism are well understood in plants, the information is limited for cyanobacteria. In this study, we first experimentally confirmed a prenylation of tRNA by recombinant isopentenyl transferase NoIPT2 from Nostoc sp. PCC 7120, whose encoding gene we previously identified in Nostoc genome along with the gene for adenylate isopentenyl transferase NoIPT1. In contrast to NoIPT2, the transcription of NoIPT1 was strongly activated during the dark period and was followed by an increase in the cytokinin content several hours later in the light period. Dominant cytokinin metabolites detected at all time points were free bases and monophosphates of isopentenyladenine and cis-zeatin, while N-glucosides were not detected at all. Whole transcriptome differential expression analysis of cultures of the above Nostoc strain treated by cytokinin compared to untreated controls indicated that cytokinin together with light trigger expression of several genes related to signal transduction, including two-component sensor histidine kinases and two-component hybrid sensors and regulators. One of the affected histidine kinases with a cyclase/histidine kinase-associated sensory extracellular domain similar to the cytokinin-binding domain in plant cytokinin receptors was able to modestly bind isopentenyladenine. The data show that the genetic disposition allows Nostoc not only to produce free cytokinins and prenylate tRNA but also modulate the cytokinin biosynthesis in response to light, triggering complex changes in sensing and regulation.
Cytokinins, a class of phytohormones, are adenine derivatives common to many different organisms. In plants, these play a crucial role as regulators of plant development and the reaction to abiotic and biotic stress. Key enzymes in the cytokinin synthesis and degradation in modern land plants are the isopentyl transferases and the cytokinin dehydrogenases, respectively. Their encoding genes have been probably introduced into the plant lineage during the primary endosymbiosis. To shed light on the evolution of these proteins, the genes homologous to plant adenylate isopentenyl transferase and cytokinin dehydrogenase were amplified from the genomic DNA of cyanobacterium Nostoc sp. PCC 7120 and expressed in Escherichia coli. The putative isopentenyl transferase was shown to be functional in a biochemical assay. In contrast, no enzymatic activity was detected for the putative cytokinin dehydrogenase, even though the principal domains necessary for its function are present. Several mutant variants, in which conserved amino acids in land plant cytokinin dehydrogenases had been restored, were inactive. A combination of experimental data with phylogenetic analysis indicates that adenylate-type isopentenyl transferases might have evolved several times independently. While the Nostoc genome contains a gene coding for protein with characteristics of cytokinin dehydrogenase, the organism is not able to break down cytokinins in the way shown for land plants.
- MeSH
- Biological Evolution MeSH
- Cytokinins metabolism MeSH
- Escherichia coli enzymology growth & development MeSH
- Phylogeny MeSH
- Plants, Genetically Modified genetics growth & development metabolism MeSH
- Molecular Sequence Data MeSH
- Mutation genetics MeSH
- Mutagenesis, Site-Directed MeSH
- Nostoc enzymology genetics MeSH
- Oxidoreductases genetics metabolism MeSH
- Dimethylallyltranstransferase genetics metabolism MeSH
- Gene Expression Regulation, Enzymologic MeSH
- Recombinant Proteins metabolism MeSH
- Amino Acid Sequence MeSH
- Sequence Homology, Amino Acid MeSH
- Nicotiana enzymology growth & development MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Cyanobacteria are photosynthetic prokaryotes found in a range of environments. They are infamous for the production of toxins, as well as bioactive compounds, which exhibit anticancer, antimicrobial and protease inhibition activities. Cyanobacteria produce a broad range of antifungals belonging to structural classes, such as peptides, polyketides and alkaloids. Here, we tested cyanobacteria from a wide variety of environments for antifungal activity. The potent antifungal macrolide scytophycin was detected in Anabaena sp. HAN21/1, Anabaena cf. cylindrica PH133, Nostoc sp. HAN11/1 and Scytonema sp. HAN3/2. To our knowledge, this is the first description of Anabaena strains that produce scytophycins. We detected antifungal glycolipopeptide hassallidin production in Anabaena spp. BIR JV1 and HAN7/1 and in Nostoc spp. 6sf Calc and CENA 219. These strains were isolated from brackish and freshwater samples collected in Brazil, the Czech Republic and Finland. In addition, three cyanobacterial strains, Fischerella sp. CENA 298, Scytonema hofmanni PCC 7110 and Nostoc sp. N107.3, produced unidentified antifungal compounds that warrant further characterization. Interestingly, all of the strains shown to produce antifungal compounds in this study belong to Nostocales or Stigonematales cyanobacterial orders.
- MeSH
- Anabaena chemistry classification growth & development isolation & purification MeSH
- Antifungal Agents chemistry isolation & purification pharmacology MeSH
- Aspergillus flavus drug effects growth & development MeSH
- Candida albicans drug effects growth & development MeSH
- Peptides, Cyclic chemistry isolation & purification pharmacology MeSH
- Species Specificity MeSH
- Phylogeny MeSH
- Glycolipids chemistry isolation & purification pharmacology MeSH
- Lipopeptides chemistry isolation & purification pharmacology MeSH
- Molecular Structure MeSH
- Molecular Typing MeSH
- Nostoc chemistry classification growth & development isolation & purification MeSH
- Drug Discovery * MeSH
- Pyrans chemistry isolation & purification pharmacology MeSH
- Cyanobacteria chemistry classification growth & development isolation & purification MeSH
- Fresh Water microbiology MeSH
- Saline Waters MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Geographicals
- Brazil MeSH
- Czech Republic MeSH
- Finland MeSH
High performance countercurrent chromatography (HPCCC) was successfully applied for the separation of nostotrebin 6 from cultivated soil cyanobacteria in a two-step operation. A two-phase solvent system composed of n-hexane-ethyl acetate-methanol-water (4:5:4:5, v/v/v/v) was employed for the HPCCC separation. In the first-step operation, its neutral upper phase was used as stationary phase and its basic lower phase (1% NH3 in lower phase) was employed as mobile phase at a flow rate of 1 mL/min. In the second operation step, its neutral upper phase was used as stationary phase, whereas both its neutral lower phase and basic lower phase were employed as mobile phase with a linear gradient elution at a flow rate of 0.8 mL/min. The revolution speed and temperature of the separation column were 1,000 rpm and 30 °C, respectively. Using HPCCC followed by clean-up on Sephadex LH-20 gel, 4 mg of nostotrebin 6 with a purity of 99% as determined by HPLC/DAD-ESI-HRMS was obtained from 100 mg of crude extract. The chemical identity of the isolated compound was confirmed by comparing its spectroscopic data (UV, ESI-HRMS, ESI-HRMS2) with those of an authentic standard and data available in the literature.
- MeSH
- Acetates chemistry MeSH
- Cholinesterase Inhibitors chemistry isolation & purification MeSH
- Cyclopentanes chemistry isolation & purification MeSH
- Hexanes chemistry MeSH
- Spectrometry, Mass, Electrospray Ionization MeSH
- Methanol chemistry MeSH
- Nostoc chemistry MeSH
- Countercurrent Distribution MeSH
- Soil Microbiology MeSH
- Solvents chemistry MeSH
- Water chemistry MeSH
- Chromatography, High Pressure Liquid MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
