Étude préliminaire des communautés bactériennes épiphytes de Laminara digitata

1989 ◽  
Vol 35 (7) ◽  
pp. 740-743 ◽  
Author(s):  
Sophie Corre ◽  
Daniel Prieur ◽  
Simone Chamroux ◽  
Jean-Yves Floch ◽  
Annick Hourmant
Keyword(s):  
Bacterial Communities ◽  
Physiological State ◽  
Atlantic Coast ◽  
Epiphytic Bacteria ◽  
Atp Content ◽  
Laminaria Digitata ◽  
Density Values ◽  
Different Levels ◽  
Different Parts

Algal samples from different parts of the frond of Laminaria digitata (young, adult and aged tissues) and from macroscopic fragments naturally separated from the thallus were collected on the Atlantic coast of France (Brittany) during winter and spring. Bacterial communities associated with the different levels were compared, and the ATP content was determined and used as an indicator of the physiological state of the tissues. It is higher in young tissue (55 nmol/g of fresh kelp) than in fragments (9 nmol/g of fresh kelp), showing a decrease in the number of metabolically active cells. If total bacterial density values are relatively close on the different parts of the kelp (average, 2.9 × 107 bacteria/cm2), culturable microflora increased from young tissue (minimum, 15 cfu/cm2) to fragments (average, 3.6 × 107 bacteria/cm2). Characterization of strains showed an increase of metabolic activity together with a diversification in the culturable fraction with the age of algal tissues.Key words: epiphytic bacteria, kelp, Laminaria digitata.

scholarly journals Characterization of hydrocarbon degrading bacteria at EPEA Station (38º 28’ S – 57º 41’ O) Atlantic coast

2020 ◽  
Vol 34 (1) ◽  
Author(s):  
Silvia Peressutti
Keyword(s):  
Bacterial Communities ◽  
Atlantic Coast ◽  
Ecological Significance ◽  
Physiological Properties ◽  
Degrading Bacteria ◽  
Surfactant Production ◽  
The Impact ◽  
Rhodococcus Sp ◽  
Over Time

Hydrocarbon degrading bacteria (HDB) were monitored since 2006 to 2018 at the Permanent Environmental Studies Station (EPEA), in order to analyze its abundance and the potentiality to metabolize these pollutants. The presence of HDB was detected with counts values ranging between 103 and 105 UFC ml-1. A slight increase was observed over time, which could be linked to changes in marine temperature reported within the last years. Thirty-six HDB were tested for growth on various hydrocarbons and some of them showed a broad biodegradation profile. Moreover, from phenanthrene (Phe) enrichment cultures, five strains were phylogenetically identified as Halomonas sp. E1, E2 and E3; Rhodococcus sp. E4 and Pseudomonas sp. E5. Complete Phe degradation was demonstrated for E4 and E5 strains, while E1, E2, E3 and E4 strains displayed surfactant production. This study contributed with the first knowledge about the intrinsic HC biodegradation potential by bacterial communities at EPEA. Some of the strains exhibited physiological properties that might have ecological significance on environmental alterations as the presence of pollutants. Particularly, Rhodococcus sp. E4 could be an alternative for microbial selection in the degradation of PAHs. Further studies are needed to evaluate the impact of the climate change on microbial-mediated detoxification processes.

Molecular characterization of the bacterial communities present in sheep's milk and cheese produced in South Brazilian Region via 16S rRNA gene metabarcoding sequencing

LWT ◽  
2021 ◽  
Vol 147 ◽  
pp. 111579
Author(s):  
Creciana M. Endres ◽  
Ícaro Maia S. Castro ◽  
Laura D. Trevisol ◽  
Juliana M. Severo ◽  
Michele B. Mann ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Molecular Characterization ◽  
Bacterial Communities ◽  
Rrna Gene

scholarly journals New Insights on the Zeugodacus cucurbitae (Coquillett) Bacteriome

2021 ◽  
Vol 9 (3) ◽  
pp. 659
Author(s):  
Elias Asimakis ◽  
Panagiota Stathopoulou ◽  
Apostolis Sapounas ◽  
Kanjana Khaeso ◽  
Costas Batargias ◽  
...  
Keyword(s):  
Relative Abundance ◽  
Bacterial Communities ◽  
High Throughput Sequencing ◽  
Mutual Exclusion ◽  
Bacterial Composition ◽  
Operational Taxonomic Units ◽  
Host Diet ◽  
Dominant Bacteria ◽  
High Degree

Various factors, including the insect host, diet, and surrounding ecosystem can shape the structure of the bacterial communities of insects. We have employed next generation, high-throughput sequencing of the 16S rRNA to characterize the bacteriome of wild Zeugodacus (Bactrocera) cucurbitae (Coquillett) flies from three regions of Bangladesh. The tested populations developed distinct bacterial communities with differences in bacterial composition, suggesting that geography has an impact on the fly bacteriome. The dominant bacteria belonged to the families Enterobacteriaceae, Dysgomonadaceae and Orbaceae, with the genera Dysgonomonas, Orbus and Citrobacter showing the highest relative abundance across populations. Network analysis indicated variable interactions between operational taxonomic units (OTUs), with cases of mutual exclusion and copresence. Certain bacterial genera with high relative abundance were also characterized by a high degree of interactions. Interestingly, genera with a low relative abundance like Shimwellia, Gilliamella, and Chishuiella were among those that showed abundant interactions, suggesting that they are also important components of the bacterial community. Such knowledge could help us identify ideal wild populations for domestication in the context of the sterile insect technique or similar biotechnological methods. Further characterization of this bacterial diversity with transcriptomic and metabolic approaches, could also reveal their specific role in Z. cucurbitae physiology.

The first sequenced Sphaerotilus natans bacteriophage– characterization and potential to control its filamentous bacterium host

2021 ◽  
Vol 97 (4) ◽  
Author(s):  
Rute Ferreira ◽  
Rui Amado ◽  
Jorge Padrão ◽  
Vânia Ferreira ◽  
Nicolina M Dias ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Bacterial Communities ◽  
Potential Application ◽  
Deleterious Effect ◽  
Wastewater Treatment Plants ◽  
Lytic Phage ◽  
Filamentous Bacterium ◽  
Sphaerotilus Natans ◽  
Isolation And Characterization

ABSTRACT Bacteriophages (phages) are ubiquitous entities present in every conceivable habitat as a result of their bacterial parasitism. Their prevalence and impact in the ecology of bacterial communities and their ability to control pathogens make their characterization essential, particularly of new phages, improving knowledge and potential application. The isolation and characterization of a new lytic phage against Sphaerotilus natans strain DSM 6575, named vB_SnaP-R1 (SnaR1), is here described. Besides being the first sequenced genome of a Sphaerotilus natans infecting phage, 99% of its 41507 bp genome lacks homology with any other sequenced phage, revealing its uniqueness and previous lack of knowledge. Moreover, SnaR1 is the first Podoviridae phage described infecting this bacterium. Sphaerotilus natans is an important filamentous bacterium due to its deleterious effect on wastewater treatment plants (WWTP) and thus, phages may play a role as novel biotechnological tools against filamentous overgrowth in WWTP. The lytic spectrum of SnaR1 was restricted to its host strain, infecting only one out of three S. natans strains and infection assays revealed its ability to reduce bacterial loads. Results suggest SnaR1 as the prototype of a new phage genus and demonstrates its potential as a non-chemical alternative to reduce S. natans DSM 6575 cells.

scholarly journals Simultaneous determination of various platycosides in Four Platycodon grandiflorum cultivars by UPLC-QTOF/MS

2019 ◽  
Vol 62 (1) ◽  
Author(s):  
Dae Young Lee ◽  
Bo-Ram Choi ◽  
Jae Won Lee ◽  
Yurry Um ◽  
Dahye Yoon ◽  
...  
Keyword(s):  
Principal Component ◽  
Ultra Performance Liquid Chromatography ◽  
Platycodon Grandiflorum ◽  
Pentacyclic Triterpenoid ◽  
Flight Mass Spectrometry ◽  
Platycodi Radix ◽  
Isomeric Pairs ◽  
Different Levels

Abstract In Platycodi Radix (root of Platycodon grandiflorum), there are a number of platycosides that consist of a pentacyclic triterpenoid aglycone and two sugar moieties. Due to the pharmacological activities of platycosides, it is critical to assess their contents in PR, and develop an effective method to profile various platycosides is required. In this study, an analytical method based on ultra performance liquid chromatography coupled with quadrupole time-of-flight/mass spectrometry (UPLC-QTOF/MS) with an in-house library was developed and applied to profile various platycosides from four different Platycodi Radix cultivars. As a result, platycosides, including six isomeric pairs, were successfully analyzed in the PRs. In the principal component analysis, several platycosides were represented as main variables to differentiate the four Platycodi Radix cultivars. Their different levels of platycosides were also represented by relative quantification. Finally, this study indicated the proposed method based on the UPLC-QTOF/MS can be an effective tool for identifying the detail characterization of various platycosides in the Platycodi Radix.

scholarly journals Spectral Decomposition of the Flow and Characterization of the Sound Signals through Stenoses with Different Levels of Severity

2021 ◽  
Vol 8 (3) ◽  
pp. 41
Author(s):  
Fardin Khalili ◽  
Peshala T. Gamage ◽  
Amirtahà Taebi ◽  
Mark E. Johnson ◽  
Randal B. Roberts ◽  
...  
Keyword(s):  
Pressure Fluctuations ◽  
High Energy ◽  
Sound Sources ◽  
Severity Level ◽  
Non Invasive ◽  
Flow Through ◽  
Severity Of The Disease ◽  
Proper Orthogonal ◽  
Different Levels

Treatments of atherosclerosis depend on the severity of the disease at the diagnosis time. Non-invasive diagnosis techniques, capable of detecting stenosis at early stages, are essential to reduce associated costs and mortality rates. We used computational fluid dynamics and acoustics analysis to extensively investigate the sound sources arising from high-turbulent fluctuating flow through stenosis. The frequency spectral analysis and proper orthogonal decomposition unveiled the frequency contents of the fluctuations for different severities and decomposed the flow into several frequency bandwidths. Results showed that high-intensity turbulent pressure fluctuations appeared inside the stenosis for severities above 70%, concentrated at plaque surface, and immediately in the post-stenotic region. Analysis of these fluctuations with the progression of the stenosis indicated that (a) there was a distinct break frequency for each severity level, ranging from 40 to 230 Hz, (b) acoustic spatial-frequency maps demonstrated the variation of the frequency content with respect to the distance from the stenosis, and (c) high-energy, high-frequency fluctuations existed inside the stenosis only for severe cases. This information can be essential for predicting the severity level of progressive stenosis, comprehending the nature of the sound sources, and determining the location of the stenosis with respect to the point of measurements.

Characterization of the Physiological State of Microorganisms Using the Respiration Electrode

1988 ◽  
Vol 21 (8) ◽  
pp. 1305-1322 ◽  
Author(s):  
K. Riedel ◽  
P. Liebs ◽  
R. Reinneberg ◽  
F. Scheller
Keyword(s):  
Physiological State
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