scholarly journals Cyclical Patterns Affect Microbial Dynamics in the Water Basin of a Nuclear Research Reactor

2021 ◽  
Vol 12 ◽  
Author(s):  
Valérie Van Eesbeeck ◽  
Ruben Props ◽  
Mohamed Mysara ◽  
Pauline C. M. Petit ◽  
Corinne Rivasseau ◽  
...  
Keyword(s):  
Research Reactor ◽  
Nuclear Research ◽  
Amplicon Sequencing ◽  
Cell Number ◽  
Dead Cell ◽  
Chemical Parameters ◽  
Water Basin ◽  
16S Rrna Amplicon Sequencing ◽  
Physico Chemical ◽  
Nuclear Research Reactor

The BR2 nuclear research reactor in Mol, Belgium, runs in successive phases of operation (cycles) and shutdown, whereby a water basin surrounding the reactor vessel undergoes periodic changes in physico-chemical parameters such as flow rate, temperature, and radiation. The aim of this study was to explore the microbial community in this unique environment and to investigate its long-term dynamics using a 16S rRNA amplicon sequencing approach. Results from two sampling campaigns spanning several months showed a clear shift in community profiles: cycles were mostly dominated by two Operational Taxonomic Units (OTUs) assigned to unclassified Gammaproteobacterium and Pelomonas, whereas shutdowns were dominated by an OTU assigned to Methylobacterium. Although 1 year apart, both campaigns showed similar results, indicating that the system remained stable over this 2-year period. The community shifts were linked with changes in physico-chemical parameters by Non-metric Multidimensional Scaling (NMDS) and correlation analyses. In addition, radiation was hypothesized to cause a decrease in cell number, whereas temperature had the opposite effect. Chemoautotrophic use of H2 and dead cell recycling are proposed to be used as a strategies for nutrient retrieval in this extremely oligotrophic environment.

scholarly journals Metabarcoding Cyanobacteria in coastal waters and sediment in central and southern Adriatic Sea

2020 ◽  
Vol 79 (2) ◽  
pp. 157-169 ◽  
Author(s):  
Anamarija Kolda ◽  
Zrinka Ljubešić ◽  
Ana Gavrilović ◽  
Jurica Jug-Dujaković ◽  
Kristina Pikelj ◽  
...  
Keyword(s):  
Water Column ◽  
Adriatic Sea ◽  
Anthropogenic Activities ◽  
Fish Fauna ◽  
Amplicon Sequencing ◽  
Chemical Parameters ◽  
16S Rrna Amplicon Sequencing ◽  
Physico Chemical ◽  
Indicator Group ◽  
Tropical Areas

Seasonal sampling of the seawater column and sediment in Adriatic coastal areas affected by various anthropogenic activities, primarily aquaculture, was conducted during 2017. In total, 32 samples from two sites (central and southern Adriatic) were analysed by 16S rRNA amplicon sequencing. This approach was selected to test the possibilities of using metabarcoding in studying marine cyanobacteria, exploring their ecology and potential as an indicator group in anthropologically stressed coastal environments. Additionally, physicochemical water column parameters, sediment granulometry and composition were assessed. Water column revealed a seasonal variation of amplicon sequencing variants (ASVs) closely related to Cyanobium PCC-6307, Prochlorococcus MIT9313 and Synechococcus CC9902, as well as seasonal grouping of physico-chemical parameters in PCA analysis. Sediment analysis uncovered greater community richness of 13 cyanobacterial genera and two uncultured groups. The most abundant in sandy gravels and gravelly sand type of sediments were ASVs closely related to Pleurocapsa PCC-7319 and Xenococcus PCC-7305. Furthermore, identified cyanobacterial ASVs predominantly displayed similarity to isolates from tropical areas (e.g. Neolyngbya, Chroococcidiopsis, Trichodesmium, etc.), which could indicate the tropicalization process already ongoing in the fish fauna of the Adriatic Sea.

scholarly journals MCNP model of L-54M nuclear research reactor: validation by preliminary graphite radiological characterization

2019 ◽  
Vol 322 (3) ◽  
pp. 1341-1350
Author(s):  
Eros Mossini ◽  
Luca Codispoti ◽  
Giorgio Parma ◽  
Filippo Maria Rossi ◽  
Elena Macerata ◽  
...  
Keyword(s):  
Research Reactor ◽  
Nuclear Research ◽  
Nuclear Research Reactor ◽  
Radiological Characterization

scholarly journals Prokaryotic Communities in the Thalassohaline Tuz Lake, Deep Zone, and Kayacik, Kaldirim and Yavsan Salterns (Turkey) Assessed by 16S rRNA Amplicon Sequencing

2021 ◽  
Vol 9 (7) ◽  
pp. 1525
Author(s):  
Can Akpolat ◽  
Ana Beatriz Fernández ◽  
Pinar Caglayan ◽  
Baris Calli ◽  
Meral Birbir ◽  
...  
Keyword(s):  
16S Rrna ◽  
Salt Lake ◽  
Amplicon Sequencing ◽  
Deep Zone ◽  
Biotechnological Potential ◽  
16S Rrna Amplicon Sequencing ◽  
Physico Chemical ◽  
Potential Applications ◽  
A Minor ◽  
Tuz Lake

Prokaryotic communities and physico-chemical characteristics of 30 brine samples from the thalassohaline Tuz Lake (Salt Lake), Deep Zone, Kayacik, Kaldirim, and Yavsan salterns (Turkey) were analyzed using 16S rRNA amplicon sequencing and standard methods, respectively. Archaea (98.41% of reads) was found to dominate in these habitats in contrast to the domain Bacteria (1.38% of reads). Representatives of the phylum Euryarchaeota were detected as the most predominant, while 59.48% and 1.32% of reads, respectively, were assigned to 18 archaeal genera, 19 bacterial genera, 10 archaeal genera, and one bacterial genus that were determined to be present, with more than 1% sequences in the samples. They were the archaeal genera Haloquadratum, Haloarcula, Halorhabdus, Natronomonas, Halosimplex, Halomicrobium, Halorubrum, Halonotius, Halolamina, Halobacterium, and Salinibacter within the domain Bacteria. The genera Haloquadratum and Halorhabdus were found in all sampling sites. While Haloquadratum, Haloarcula, and Halorhabdus were the most abundant genera, two uncultured Tuz Lake Halobacteria (TLHs) 1 and 2 were detected in high abundance, and an additional uncultured haloarchaeal TLH-3 was found as a minor abundant uncultured taxon. Their future isolation in pure culture would permit us to expand our knowledge on hypersaline thalassohaline habitats, as well as their ecological role and biomedical and biotechnological potential applications.

State of the Art of Nuclear Reactor Instrument Automation

1974 ◽  
Vol 96 (4) ◽  
pp. 394-398
Author(s):  
M. Taeschner ◽  
R. Gariod
Keyword(s):  
High Performance ◽  
Nuclear Reactor ◽  
Research Reactor ◽  
State Of The Art ◽  
Nuclear Research ◽  
Automation System ◽  
Nuclear Research Reactor ◽  
High Investment

Due to its complexity, nuclear reactor instrument automation is a challenge to engineers. High investment and running costs of a nuclear research reactor imply the use of advanced equipment and concepts for instrument automation when striving for high performance, reliability, and operational convenience under budgetary pressure. The article describes a successfully operating instrument automation system stressing the important underlying concepts trying to avoid too much details on specific hardware which is dependent on the time when one must order things.

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