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154 results for “cyanobacterium”
Data from: Cyanophage propagation in the freshwater cyanobacterium Phormidium is constrained by phosphorus limitation and enhanced by elevated pCO2
<p>Intensification of human activities has led to changes in the availabilities of CO<sub>2</sub> and nutrients in freshwater ecosystems, which may greatly alter the physiological status of phytoplankton. Viruses require hosts for their reproduction and shifts in phytoplankton host physiology through global environmental change may thus affect viral infections as well. Various studies have investigated the impacts of single environmental factors on phytoplankton virus propagation, yet little is known about the impacts of multiple factors, particularly in freshwater systems. We therefore tested the combined effects of phosphorus limitation and elevated pCO<sub>2</sub> on the propagation of a cyanophage infecting a freshwater cyanobacterium. To this end, we cultured Phormidium in P-limited chemostats under ambient (400 µatm) and elevated (800 µatm) pCO<sub>2</sub> at growth rates of 0.6, 0.3, and 0.05 d<sup>-1</sup>. Host C:P ratios generally increased with strengthened P-limitation and with elevated pCO<sub>2</sub>. Upon host steady state conditions, virus growth characteristics were obtained in separate infection assays where hosts were infected by the double-stranded DNA cyanophage PP. Severe P-limitation (host growth 0.05 d<sup>-1</sup>) led to a 85% decrease in cyanophage production rate and a 73% decrease in burst size compared to the 0.6 d<sup>-1</sup> grown P-limited cultures. Elevated pCO<sub>2</sub> induced a 96% increase in cyanophage production rate and a 57% increase in burst size, as well as an 85% shorter latent period as compared to ambient pCO<sub>2</sub> at the different host growth rates. In addition, elevated pCO<sub>2</sub> caused a decrease in the plaquing efficiency and an increase in the abortion percentage for the 0.05 d<sup>-1</sup> P-limited treatment, while the plaquing efficiency increased for the 0.6 d<sup>-1</sup> P-limited cultures. Together, our results demonstrate interactive effects of elevated pCO<sub>2</sub> and P-limitation on cyanophage propagation, and show that viral propagation is generally constrained by P-limitation but enhanced with elevated pCO<sub>2</sub>. Our findings indicate that global change will likely have a severe impact on virus growth characteristics and thereby on the control of cyanobacterial hosts in freshwater ecosystems.</p>
Data from: Expanding the described metabolome of the marine cyanobacterium Moorea producens JHB through orthogonal natural products workflows
Moorea producens JHB, a Jamaican strain of tropical filamentous marine cyanobacteria, has been extensively studied by traditional natural products techniques. These previous bioassay and structure guided isolations led to the discovery of two exciting classes of natural products, hectochlorin (1) and jamaicamides A (2) and B (3). In the current study, mass spectrometry-based 'molecular networking' was used to visualize the metabolome of Moorea producens JHB, and both guided and enhanced the isolation workflow, revealing additional metabolites in these compound classes. Further, we developed additional insight into the metabolic capabilities of this strain by genome sequencing analysis, which subsequently led to the isolation of a compound unrelated to the jamaicamide and hectochlorin families. Another approach involved stimulation of the biosynthesis of a minor jamaicamide metabolite by cultivation in modified media, and provided insights about the underlying biosynthetic machinery as well as preliminary structure-activity information within this structure class. This study demonstrated that these orthogonal approaches are complementary and enrich secondary metabolomic coverage even in an extensively studied bacterial strain.
Fig. 6 in A novel filamentous cyanobacterium Microseira minor sp. nov. (Oscillatoriaceae, Cyanobacteria) from the Ganfu Channel, Jiangxi, China
Fig. 6. Bayesian inference (BI) phylogenetic tree based on nifH gene sequences. Bootstrap values of Bayesian posterior probabilities greater than 0.50 are showed on the BI tree. The novel filamentous species of this study is indicated in bold. Bar, 0.05.
Fig. 4 in A novel filamentous cyanobacterium Microseira minor sp. nov. (Oscillatoriaceae, Cyanobacteria) from the Ganfu Channel, Jiangxi, China
Fig. 4. Bayesian inference (BI) phylogenetic tree based on 16S rRNA gene sequences. Bootstrap values of Bayesian posterior probabilities greater than 0.50 are showed on the BI tree. The novel filamentous strains of this study is indicated in bold. Bar, 0.03.
Fig. 2 in A novel filamentous cyanobacterium Microseira minor sp. nov. (Oscillatoriaceae, Cyanobacteria) from the Ganfu Channel, Jiangxi, China
Fig. 2. Ultrastructure of Microseira minor strains. (Cw, cell wall, Th, thylakoids, Nu, nucleoplasm, Sh, sheath). Scale bars: A–D, 2 μm.
Fig. 1 in A novel filamentous cyanobacterium Microseira minor sp. nov. (Oscillatoriaceae, Cyanobacteria) from the Ganfu Channel, Jiangxi, China
Fig. 1. Light microscopy of Microseira minor strains. A–C. Immature filaments with colourless sheaths (Arrow indicates sheath). D–G. Trichome fragmentation and formation of necridia (Arrows indicate fragmentation of trichomes and formation of necridias). H–I. Old filaments with lamellated sheaths (Arrows indicate lamellated sheaths). Scale bars: 20 μm.
Fig. 3 in A novel filamentous cyanobacterium Microseira minor sp. nov. (Oscillatoriaceae, Cyanobacteria) from the Ganfu Channel, Jiangxi, China
Fig. 3. Phylogenetic tree of 16S rRNA gene sequences (1208bp) with maximum-likelihood (ML) analysis. Bootstrap values greater than 50% are showed on the ML tree. The novel filamentous strains of this study is indicated in bold. Bar, 0.03.
Fig. 5 in A novel filamentous cyanobacterium Microseira minor sp. nov. (Oscillatoriaceae, Cyanobacteria) from the Ganfu Channel, Jiangxi, China
Fig. 5. Phylogenetic tree based on nifH gene sequences (298bp) with maximum-likelihood (ML) analysis. Bootstrap values greater than 50% are showed on the ML tree. The novel filamentous species of this study is indicated in bold. Bar, 0.07.
FIGURE 3. Secondary structures for the D1–D1 in New cyanobacterium Aliterella vladivostokensis sp. nov. (Aliterellaceae, Chroococcidiopsidales), isolated from temperate monsoon climate zone (Vladivostok, Russia)
FIGURE 3. Secondary structures for the D1–D1′ helices in the ITS regions for five Aliterella species and putative genus member Synechocystis sp. PCC 7509. Conservative nucleotides are grey colored.The unique marker mutations for the new species A. vladivostokensis are black colored. Arrowheads show compensatory (CBCs) and hemi-compensatory base changes (hCBCs). Homological base pairs among different species are indicated by dotted lines.
FIGURE 5 in True branching and phenotypic plasticity in the planktonic cyanobacterium Dolichospermum brachiatum sp. nov. (Nostocales, Aphanizomenonaceae), from south-eastern Australia
FIGURE 5. Phylogenetic tree based on partial 16S ribosomal RNA gene sequence (1518 base pairs) of 128 OTUs showing the phylogenetic position of Dolichospermum brachiatum. Numbers indicate bootstrap values (> 50%) from 1000 replicates of ML and NJ analyses respectively. GenBank accession numbers are shown in parentheses. Scale bar = 0.01 nucleotide substitutions per site.
FIGURE 2 in True branching and phenotypic plasticity in the planktonic cyanobacterium Dolichospermum brachiatum sp. nov. (Nostocales, Aphanizomenonaceae), from south-eastern Australia
FIGURE 2. Sequence of development of T-type true branching of Dolichospermum brachiatum from Waranga Basin. Scale bars = 20 μm.
FIGURE 7 in True branching and phenotypic plasticity in the planktonic cyanobacterium Dolichospermum brachiatum sp. nov. (Nostocales, Aphanizomenonaceae), from south-eastern Australia
FIGURE 7. Secondary structure of the ITS sequence in D. brachiatum and allied species. Circles and oblongs highlight the differences in the structures; (A–D) D1-D1′ helix (A) D. brachiatum strains WB20619.B1, WB20619.B3, WB20619.C1 and WB20619.C2, (B) D. planctonicum strains 1-3; 19-1; 23-10; NRERC-101; D. ucrainicum CHAB623, (C) D. affinis CHAB28, (D) D. lemmermanni BC Ana 0032. (E–H) Box B helix (E) D. brachiatum strains WB20619.B1, WB20619.B3, WB20619.C1 and WB20619.C2, (F) D. planctonicum strains 1-3; 19-1; 23-10; NRERC-101; D. ucrainicum CHAB623, (G) D. affinis CHAB28 and CHAB964; D. flos-aquae CHAB1652 and NIES 1669, (H) D. lemmermannii BC Ana 0032. (I–M) V3 helix (I) D. brachiatum strains WB20619.B1, WB20619.B3, WB20619.C1 and WB20619.C2, (J) D. planctonicum strain 1-3; 1-9; 19-1; 23-10; NRERC-101, (K) D. affinis CHAB28; D. flos-aquae CHAB1652 and NIES 1669, (L) D. ucrainicum CHAB623, (M) D. lemmermannii BC Ana 0032.
FIGURE 6 in True branching and phenotypic plasticity in the planktonic cyanobacterium Dolichospermum brachiatum sp. nov. (Nostocales, Aphanizomenonaceae), from south-eastern Australia
FIGURE 6. Phylogenetic tree based on the ITS sequence of the 16S–23S rRNA operon of 25 OTUs showing the phylogenetic position of Dolichospermum brachiatum. Numbers indicate bootstrap values> 50% from 1000 replicates of ML and NJ analyses respectively. GenBank accession numbers shown in parentheses. Scale bar = 0.05 nucleotide substitutions per site. Strains isolated and sequenced in this study shown in bold.
Cultivation of the PHB-producing cyanobacterium Synechococcus leopoliensis in a pilot-scale open system using nitrogen from waste streams
<p class="MsoNormal"><span>The cultivation of PHB-producing cyanobacteria is a promising approach to obtain the raw material for bio-based and biodegradable plastics. To commercialise photoautotrophic PHB production, the cultivation needs to be scaled up in open cultivation systems and to improve sustainability of the process, nutrients must be obtained from waste streams. Different PHB-producing cyanobacteria were compared in laboratory-scale cultivations using either water from recirculating aquaculture systems or pre-processed liquid digestate as nutrient sources. The species <em>Synechococcus leopoliensis</em> was cultivated in an open thin-layer photobioreactor (18 m<sup>2</sup>, 200 L), were growth in mineral Z-medium was again compared to said waste streams. Cultivation in mineral medium resulted in both the highest final biomass yield (6 g L<sup>-1</sup>) and productivity (0.7 g L<sup>-1</sup> d<sup>-1</sup>). Both waste stream-based media showed lower biomass yields and productivities (2 g L<sup>-1 </sup>and 0.25–0.3 g L<sup>-1</sup> d<sup>-1</sup>). However, due to differences in the cultivation conditions (e.g., temperature, nutrient supply), final biomass yield and productivity do not represent the performance of the cultivations adequately. Relative parameters such as nitrogen and energy conversion ratios indicate that cultivation with aquaculture water suffered from insufficient nitrogen supply to the culture, whereas the use pre-processed liquid digestate resulted in a substantial loss of nitrogen due to volatilization. All cultivations in the open system were continued in the laboratory, where cultures were starved for ten days under nutrient-depleted conditions (without nitrogen, phosphorus, or both). While PHB accumulation occurred, concentrations were comparatively low (< 1 %<sub>dw</sub>). The comparison of the results suggests that PHB yields were influenced more by the initial cultivation condition than by the specific type of nutrient depletion. Thus, while the cultivation with waste streams in an open system is feasible, environmental parameters seem to influence PHB yields considerably and must be considered for the optimisation of the complete process.</span></p>
FIGURE 6. The 50 in Spelaeonaias gen. nov., a new true-branched cyanobacterium from Cave Vlychada (Diros, Peloponnese, Greece)
FIGURE 6. The 50% majority rule consensus tree as inferred from MrBayes. Posterior probalities are provided on or below the nodes. The GenBank accession numbers of sequences are given on the right of the taxa names. The scale corresponds to substitutions/site. Characters in bold indicate the taxon from Vlychada Cave.
FIGURE 5 in Spelaeonaias gen. nov., a new true-branched cyanobacterium from Cave Vlychada (Diros, Peloponnese, Greece)
FIGURE 5. Fluorescence emission spectrum of cells obtained by the Lambda scan module of CLSM. Two-dimensional spectral characteristic of fluorescence is illuminated with the blue laser (488 nm) and recorded as arbitrary units. Note the first peak for phycoerythrin (PE) (582 nm) and the second for phycobiliproteins (PC: phycocyanin and APC: allophycocyanin) (669 nm) including the small shoulder for chlorophyll a.
FIGURE 4. A–C in Spelaeonaias gen. nov., a new true-branched cyanobacterium from Cave Vlychada (Diros, Peloponnese, Greece)
FIGURE 4. A–C. Confocal (CLSM) photomicrographs showing filaments of Spelaeonaias floccida covered by sheaths. A. 41 x-y optical sections (z step= 0.13 μm) showing the Y-type of true branching; note the central spaces devoid of fluorescence in the filaments, corresponding to the area of nucleoids. B. 30 x-y optical sections (z step= 0.13 μm) showing a degraded basal cell (dc) promoting a false branching. C. Main filament with secondary branches; division of initial cells (at arrows) implying further formation of secondary branches. Color allocation: DNA nucleic acids labelled with Hoechst 33258, cyan; reflection from minerals, white; autofluorescence of extracellular polymeric substances, green; colocalized autofluorescence of cyanobacteria in the red (phycobilins) and blue channels (chlorophylls), magenta. Scale bars = 10 μm.
FIGURE 3. A–D in Spelaeonaias gen. nov., a new true-branched cyanobacterium from Cave Vlychada (Diros, Peloponnese, Greece)
FIGURE 3. A–D. TEM micrographs of Spelaeonaias floccida showing cell division and mode of branching. A. Filament with short barrel cells showing a general view of dividing cells for branch formation; the oblique division of an initial cell at arrow. B. Oblique section at a particular part of a filament showing one heterocyte (h) with a polar plug of cyanophycin (cy) connected to the adjacent cell by a neck; note the extra wall layer (wl) surrounding the heterocyte. C. Cell division at a certain region of the filament and formation of a new septum (s); D–E. After the first division of the initial cell (ic) the resulting cell (arrow) changes polarity and is further dividing for the formation of a secondary branch. Scale bars = 2 μm (B) and 5 μm (A–D).
FIGURE 1. A–J in Spelaeonaias gen. nov., a new true-branched cyanobacterium from Cave Vlychada (Diros, Peloponnese, Greece)
FIGURE 1. A–J. LM and SEM micrographs of Spelaeonaias floccida. A. Filaments of Spelaeonaias floccida showing the main filament and the secondary branches. B. Division of an initial cell, giving rise to two cells that change division polarity for the formation of a secondary branch. C. Secondary filament with a necridic cell (nc). D–G. Main and secondary filaments with the characteristic Y-type of branching; heterocytes at arrows. H. Hormogonia with an intercalary heterocyte at arrow. I. A single hormogonium with a terminal heterocyte (arrow). J. Single hormogonium as seen under SEM; the heterocyte (arrow) in a secondary filament is also obvious. Figs A–B from fresh material. Figs C–J from cultures. Scale bars = 10 μm (A–D, F, H, I) and 20 μm (Ε, G, J).
FIGURE 2. A–F in Spelaeonaias gen. nov., a new true-branched cyanobacterium from Cave Vlychada (Diros, Peloponnese, Greece)
FIGURE 2. A–F. TEM micrographs of Spelaeonaias floccida. A. Longitudinal section showing a septum (s) without intercellular connection between vegetative cells, the outer membrane (om) and the plasma membrane (pm). Note the thick and compact sheath near the cell wall, becoming diffluent externally. the thylakoids are scattered throughout the cyatoplasm forming curled bundles of 2–4 parallel arranged membranes, with phycobilisomes (pb) on their surface. B. Grazing thin section providing a top view of phycobilisomes as stellate structures, associated with thylakoidal membranes; the plasma membrane is followed by a thin layer of peptidoglycan (pl) and an outer membrane (om). C. Carboxysomes (cb) seen as polyhedral bodies. D. Peptidoglycan layer crossed by pore structures (arrow). E–F. Nucleoid regions surrounded by thylakoids and scattered through the cytoplasm; cy = cyanophycin granule. Scale bars = 500 nm (A, C–F) and 100 nm (B).
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Allen Brain Atlas
Allen Brain Atlas is an Allen Institute collection of brain map atlases, datasets, APIs, and analysis tools covering mouse, human, and non-human primate brain resources.
Annotated Behaviour and Observability Dataset (ABODe)
ABODe is a University of Edinburgh DataShare dataset for behavior classification in group-housed mice using home-cage video, identities, bounding boxes, ground-plate positions, and annotator labels.
DANDI Archive for NWB datasets
DANDI is a BRAIN Initiative archive for publishing and sharing neurophysiology data, including electrophysiology, optophysiology, and behavioral data packaged as NWB and related standards.
International Brain Laboratory public data
The International Brain Laboratory public data releases expose standardized mouse decision-making experiments, including Neuropixels recordings, widefield calcium imaging, behavior, and session metadata accessed through the ONE API.
OpenNeuro
OpenNeuro is a free, open platform for sharing neuroimaging datasets, with public search, dataset pages, and download paths for web, S3, DataLad, and the OpenNeuro CLI.