An Approach to Solid Phase Identification in a Ca-S-O System by Quantitative Energy Dispersive X-Ray Microanalysis

Solid phases formed in the limestone sulphation reaction were identified by scanning electron microscopy with backscattered electron (BSE) imaging and by quantitative energy dispersive X-ray (EDX) microanalysis of calcium and sulphur. Since calcium and sulphur can form several compounds in the Ca-S-O system, two quantities, the sum of oxides (CaO+SO3) and the molar ratio (CaO/SO3), were used to calculate empirical formulae for the compounds actually present. A method for analysing the experimental results is proposed, the mathematical expressions employed are presented and the numerical coefficients tabulated. It is shown with some examples that the method used here provides useful criteria for the identification of limestone sulphation products

történeti dráma 5 felvonásban - irta: Sardou Viktor - francziából forditotta: Paulay Ede és Szerdahelyi Kálmán

Debreczeni Szinház. Kedd, 1881. évi november hó 15-kán. Krecsányi Ignácz igazgatása alatti dráma-, vigjáték-, népszinmű- és operette-szintársulat által, Abonyi Gyula jutalomjátékaul.Debreceni Egyetem Egyetemi és Nemzeti Könyvtá

A gene expression study on strains of Nostoc (Cyanobacteria) revealing antimicrobial activity under mixotrophic conditions

Cyanobacteria are well known for their production of a multitude of highly allelopathic compounds. These products have features such as incorporation of non-proteinogenic amino acids which are characteristics of peptides biosynthesized by non-ribosomal peptide synthetases (NRPSs). Some of these peptides have acetate-derived moieties, suggesting that their biosynthesis also involves polyketide synthases (PKSs). Among the photosynthetic microorganisms, cyanobacteria belonging to the genus Nostoc are regarded as good candidates for producing biologically active secondary metabolites. Aiming at the maximization in the production of natural product, we compared autotrophic, and mixotrophic growth at high light intensity of two Nostoc species in relation to the production of bioactive compounds with the antimicrobial activity at different source of sugar. Glucose was shown to be the best substrate for the production of high natural product when compared with sucrose. Also, the rate of biomass production and antimicrobial activity was reaching ~2.0 to 2.5 and ~1.5 times greater than that of the autotrophic and sucrose grown cultures, respectively. Also, we conduct a combined NRPSs and PKSs polymerase chain reaction (PCR). The sequences presented in this study was deposited in GenBank and had accession numbers JF795278 and JF795279 (NRPS A domains) and JF795280 and JF795281 (PKS KS domains). Computer modeling and phylogenetic analysis was conducted to predict the putative amino acid recognized by the unknown adenylation domain in the NRPS sequences. This study highlights the importance of environmental and nutrimental factors in maximization of antibiotic production of two Nostoc species.Keywords: Peptide synthetase gene, polyketide synthase gene, Nostoc, secondary metabolites, mixotrophic condition

Production of High Amounts of Hepatotoxin Nodularin and New Protease Inhibitors Pseudospumigins by the Brazilian Benthic Nostoc sp CENA543

Nostoc is a cyanobacterial genus, common in soils and a prolific producer of natural products. This research project aimed to explore and characterize Brazilian cyanobacteria for new bioactive compounds. Here we report the production of hepatotoxins and new protease inhibitors from benthic Nostoc sp. CENA543 isolated from a small, shallow, saline-alkaline lake in the Nhecolandia, Pantanal wetland area in Brazil. Nostoc sp. CENA543 produces exceptionally high amounts of nodularin-R. This is the first free-living Nostoc that produces nodularin at comparable levels as the toxic, bloom-forming, Nodularia spumigena. We also characterized pseudospumigins A-F, which are a novel family of linear tetrapeptides. Pseudospumigins are structurally related to linear tetrapeptide spumigins and aeruginosins both present in N. spumigena but differ in respect to their diagnostic amino acid, which is Ile/Leu/Val in pseudospumigins, Pro/mPro in spumigins, and Choi in aeruginosins. The pseudospumigin gene cluster is more similar to the spumigin biosynthetic gene cluster than the aeruginosin gene cluster. Pseudospumigin A inhibited trypsin (IC50 4.5 mu M after 1 h) in a similar manner as spumigin E from N. spumigena but was almost two orders of magnitude less potent. This study identifies another location and environment where the hepatotoxic nodularin has the potential to cause the death of eukaryotic organisms.Peer reviewe

Maximum rates of N2 fixation and primary production are out of phase in a developing cyanobacterial bloom in the Baltic Sea

Although N2-fixing cyanobacteria contribute significantly to oceanic sequestration of atmospheric CO2, little is known about how N2 fixation and carbon fixation (primary production) interact in natural populations of marine cyanobacteria. In a developing cyanobacterial bloom in the Baltic Sea, rates of N2 fixation (acetylene reduction) showed both diurnal and longer-term fluctuations. The latter reflected fluctuations in the nitrogen status of the cyanobacterial population and could be correlated with variations in the ratio of acetylene reduced to 15N2 assimilated. The value of this ratio may provide useful information about the release of newly fixed nitrogen by a cyanobacterial population. However, although the diurnal fluctuations in N2 fixation broadly paralleled diurnal fluctuations in carbon fixation, the longer-term fluctuations in these two processes were out of phase

Combined and single effects of pesticide carbaryl and toxic Microcystis aeruginosa on the life history of Daphnia pulicaria

The combined influence of a pesticide (carbaryl) and a cyanotoxin (microcystin LR) on the life history of Daphnia pulicaria was investigated. At the beginning of the experiments animals were pulse exposed to carbaryl for 24 h and microcystins were delivered bound in Microcystis’ cells at different, sub-lethal concentrations (chronic exposure). In order to determine the actual carbaryl concentrations in the water LC–MS/MS was used. For analyses of the cyanotoxin concentration in Daphnia’s body enzyme-linked immunosorbent assay (ELISA) was used. Individual daphnids were cultured in a flow-through system under constant light (16 h of light: 8 h of dark), temperature (20°C), and food conditions (Scenedesmus obliquus, 1 mg of C l−1). The results showed that in the treatments with carbaryl egg numbers per female did not differ significantly from controls, but the mortality of newborns increased significantly. Increasing microcystin concentrations significantly delayed maturation, reduced size at first reproduction, number of eggs, and newborns. The interaction between carbaryl and Microcystis was highly significant. Animals matured later and at a smaller size than in controls. The number of eggs per female was reduced as well. Moreover, combined stressors caused frequent premature delivery of offspring with body deformations such as dented carapax or an undeveloped heart. This effect is concluded to be synergistic and could not be predicted from the effects of the single stressors.

The Council of Europe's Approach towards Ageism

In this chapter, I examine the degree of interest in ageism among Council of Europe members, and the degree of interest in its elimination through the Council of Europe forum. I also examine the interpretation of the concept of ageism by various Council of Europe institutions. Finally, I explore the Council’s willingness and ability to eliminate or at least mitigate ageism effect

The swinholide biosynthesis gene cluster from a terrestrial cyanobacterium, Nostoc sp. strain UHCC 0450

Swinholides are 42-carbon ring polyketides with a 2-fold axis of symmetry. They are potent cytotoxins that disrupt the actin cytoskeleton. Swinholides were discovered from the marine sponge Theonella sp. and were long suspected to be produced by symbiotic bacteria. Misakinolide, a structural variant of swinholide, was recently demonstrated to be the product of a symbiotic heterotrophic proteobacterium. Here, we report the production of swinholide A by an axenic strain of the terrestrial cyanobacterium Nostoc sp. strain UHCC 0450. We located the 85-kb trans-AT polyketide synthase (PKS) swinholide biosynthesis gene cluster from a draft genome of Nostoc sp. UHCC 0450. The swinholide and misakinolide biosynthesis gene clusters share an almost identical order of catalytic domains, with 85% nucleotide sequence identity, and they group together in phylogenetic analysis. Our results resolve speculation around the true producer of swinholides and demonstrate that bacteria belonging to two distantly related phyla both produce structural variants of the same natural product. In addition, we described a biosynthesis cluster from Anabaena sp. strain UHCC 0451 for the synthesis of the cytotoxic and antifungal scytophycin. All of these biosynthesis gene clusters were closely related to each other and created a group of cytotoxic macrolide compounds produced by trans-AT PKSs of cyanobacteria and proteobacteria. © 2018 American Society for Microbiology.We thank Lyudmila Saari for purifying the cyanobacterial strains into axenic cultures. This work was supported by the Academy of Finland grants 258827 and 273798 to K.S. and 288235 to P.P. A.H. is a student at the Doctoral Programme in Microbiology and Biotechnology. A.A. was funded in part by the Strategic Funding grant UID/Multi/ 04423/2013 through national funds provided by the Portuguese National Science Foundation (FCT) and the European Regional Development Fund (ERDF) in the framework of the program PT2020, by the European Structural and Investment Funds (ESIF) through the Competitiveness and Internationalization Operational Program-COMPETE 2020, and by the Structured Programs of R&D&I INNOVMAR (NORTE-01-0145-FEDER-000035-NOVELMAR), CORAL NORTE (NORTE-01-0145-FEDER-000036), and MarInfo (NORTE-01-0145-FEDER-000031), funded by the Northern Regional Operational Pro-gram (NORTE2020) through the ERDF. The funders had no role in the study design, data collection and interpretation, or the decision to submit the work for publicatio

Dermatitis associated with exposure to a marine cyanobacterium during recreational water exposure

<p>Abstract</p> <p>Background</p> <p>Anecdotal evidence reported an outbreak of symptoms on Fraser Island during the late 1990s similar to those expected from exposure to dermotoxins found in the cyanobacterium <it>L. majuscula</it>. This coincided with the presence of a bloom of <it>L. majuscula</it>.</p> <p>Methods</p> <p>Records from the Fraser Island National Parks First aid station were examined. Information on cyanobacterial blooms at Fraser Island were obtained from Queensland National Parks rangers.</p> <p>Results</p> <p>Examination of first aid records from Fraser Island revealed an outbreak of symptoms predominantly in January and February 1998.</p> <p>Conclusion</p> <p>During a bloom of <it>L. majuscula </it>there were numerous reports of symptoms that could be attributed to dermotoxins found in <it>L. majuscula</it>. The other four years examined had no <it>L. majuscula </it>blooms and the number of <it>L. majuscula </it>symptoms was much reduced. These cases comprised a high percentage of the cases treated at the first aid station.</p