نتایج جستجو برای: nodularia spumigena

تعداد نتایج: 167  

2016
Mar Fernández-Méndez Kendra A. Turk-Kubo Pier L. Buttigieg Josephine Z. Rapp Thomas Krumpen Jonathan P. Zehr Antje Boetius

The Eurasian basin of the Central Arctic Ocean is nitrogen limited, but little is known about the presence and role of nitrogen-fixing bacteria. Recent studies have indicated the occurrence of diazotrophs in Arctic coastal waters potentially of riverine origin. Here, we investigated the presence of diazotrophs in ice and surface waters of the Central Arctic Ocean in the summer of 2012. We ident...

Journal: :Toxicon : official journal of the International Society on Toxinology 2000
B C Hitzfeld C S Lampert N Spaeth D Mountfort H Kaspar D R Dietrich

Cyanobacteria are known to produce hepatotoxic substances, the functional and ecological role of these toxins, however, remains largely unclear. Toxic properties of cyanobacteria collected in Antarctica were investigated to determine whether toxin-producing species can also be found under these environmental conditions. Samples were collected from meltwater ponds on the McMurdo Ice Shelf, Antar...

2010
Viviana R. Lopes Nuria Fernández Rosário F. Martins Vitor Vasconcelos

Cyanobacteria are a diverse group of Gram-negative bacteria that produce an array of secondary compounds with selective bioactivity against vertebrates, invertebrates, plants, microalgae, fungi, bacteria, viruses and cell lines. The aim of this study was to assess the toxic effects of aqueous, methanolic and hexane crude extracts of benthic and picoplanktonic cyanobacteria isolated from estuari...

Journal: :Microbiology 2002
Isabelle Iteman Rosmarie Rippka Nicole Tandeau de Marsac Michael Herdman

The taxonomic coherence and phylogenetic relationships of 11 planktonic heterocystous cyanobacterial isolates were examined by investigating two areas of the rRNA operon, the 16S rRNA gene (rrnS) and the internal transcribed spacer (ITS) located between the 16S rRNA and 23S rRNA genes. The rrnS sequences were determined for five strains, including representatives of Anabaena flos-aquae, Aphaniz...

2017
Kateřina Voráčová Jan Hájek Jan Mareš Petra Urajová Marek Kuzma José Cheel Andreas Villunger Alexandra Kapuscik Marcel Bally Petr Novák Martin Kabeláč Gerhard Krumschnabel Martin Lukeš Ludmila Voloshko Jiří Kopecký Pavel Hrouzek

Oxadiazines are heterocyclic compounds containing N-N-O or N-N-C-O system within a six membered ring. These structures have been up to now exclusively prepared via organic synthesis. Here, we report the discovery of a natural oxadiazine nocuolin A (NoA) that has a unique structure based on 1,2,3-oxadiazine. We have identified this compound in three independent cyanobacterial strains of genera N...

Journal: :Aquatic Sciences 2021

Abstract Heterocystous Cyanobacteria of the genus Nodularia form major blooms in brackish waters, while terrestrial Nostoc species occur worldwide, often associated biological soil crusts. Both genera, by virtue their ability to fix N 2 and conduct oxygenic photosynthesis, contribute significantly global primary productivity. Select produce hepatotoxin nodularin whether its production will chan...

Journal: :Aquatic Ecology 2021

Blooms of freshwater toxic cyanobacteria are a growing environmental health problem, enhanced by anthropogenic eutrophication and climate change. A variety techniques were tested for their remediation, from physical methods using artificial mixing or flocculation, to chemical employing synthetic natural compounds, as well constructed wetlands. In this work, we conducted an evaluation at microco...

ژورنال: :مجله گیاهشناسی ایران 2013
زینب شریعتمداری حسین ریاحی

جهت بررسی نمونه ­های خاکزی خانواده nostocaceae kützing، تاکسون­های موجود در خاک 20 ایستگاه از 7 استان دارای کشت برنج کشور مورد مطالعه قرار گرفت. طی این تحقیق در مجموع تاکسون هایی متعلق به 6 جنس از این خانواده شناسایی شد که از میان تاکسون­های شناسایی شده، 18 گونه و 1 واریته از 4 جنس nostoc vaucher ex bornet & flahault، trichormus (ralfs ex bornet & flahault) komárek & anagnostidis ، ...

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