The growth inhibition of Azotobacter chroococcum by Pseudomonas sp.

1970 ◽  
Vol 16 (1) ◽  
pp. 9-16 ◽  
Author(s):  
E. C. S. Chan ◽  
Pramila Basavanand ◽  
Tiiu Liivak
Keyword(s):  
Agar Medium ◽  
High Sensitivity ◽  
Azotobacter Chroococcum ◽  
Point Of View ◽  
Pseudomonas Sp ◽  
Microbial Interaction ◽  
Metabolic Intermediates ◽  
Microbial Association ◽  
End Products ◽  
Diffusible Factor

When Azotobacter chroococcum and Pseudomonas sp. were grown together on nitrogen-deficient azotobacter agar medium, the growth of the azotobacter was inhibited. Studies were undertaken to explain this microbial interaction. No demonstrable active diffusible factor was found in cell-free filtrates (neutralized) and extracts. Experiments with indicator agar plates and HEPES-buffered liquid medium suggested that the interaction was attributable to the transformation by the pseudomonad of metabolic intermediates of azotobacter to inhibitory acidic end products. The high sensitivity of A. chroococcum to acidity resulted in the inhibition phenomenon. This microbial association is discussed briefly from the point of view of the ecology of the two species.

scholarly journals Rock Emissivity Measurement for Infrared Thermography Engineering Geological Applications

2021 ◽  
Vol 11 (9) ◽  
pp. 3773
Author(s):  
Simone Mineo ◽  
Giovanna Pappalardo
Keyword(s):  
Surface Temperature ◽  
Infrared Thermography ◽  
High Sensitivity ◽  
Point Of View ◽  
Rock Surface ◽  
Rock Types ◽  
Ornamental Stones ◽  
Emissivity Measurement ◽  
Laboratory Tool ◽  
Non Destructive

Infrared thermography is a growing technology in the engineering geological field both for the remote survey of rock masses and as a laboratory tool for the non-destructive characterization of intact rock. In this latter case, its utility can be found either from a qualitative point of view, highlighting thermal contrasts on the rock surface, or from a quantitative point of view, involving the study of the surface temperature variations. Since the surface temperature of an object is proportional to its emissivity, the knowledge of this last value is crucial for the correct calibration of the instrument and for the achievement of reliable thermal outcomes. Although rock emissivity can be measured according to specific procedures, there is not always the time or possibility to carry out such measurements. Therefore, referring to reliable literature values is useful. In this frame, this paper aims at providing reference emissivity values belonging to 15 rock types among sedimentary, igneous and metamorphic categories, which underwent laboratory emissivity estimation by employing a high-sensitivity thermal camera. The results show that rocks can be defined as “emitters”, with emissivity generally ranging from 0.89 to 0.99. Such variability arises from both their intrinsic properties, such as the presence of pores and the different thermal behavior of minerals, and the surface conditions, such as polishing treatments for ornamental stones. The resulting emissivity values are reported and commented on herein for each different studied lithology, thus providing not only a reference dataset for practical use, but also laying the foundation for further scientific studies, also aimed at widening the rock aspects to investigate through IRT.

THE INFLUENCE OF SOIL AND ROOT EXTRACTS ON THE ASSOCIATIVE GROWTH OF SELECTED SOIL BACTERIA

1963 ◽  
Vol 9 (2) ◽  
pp. 187-197 ◽  
Author(s):  
E. C. S. Chan ◽  
H. Katznelson ◽  
J. W. Rouatt
Keyword(s):  
Mixed Culture ◽  
Soil Bacteria ◽  
Agar Medium ◽  
Soil Extract ◽  
Antagonistic Effect ◽  
Pseudomonas Sp ◽  
Population Changes ◽  
Agrobacterium Radiobacter ◽  
Root Extracts ◽  
Wheat Population

These studies are concerned with the growth interrelationships of mixed cultures of five soil organisms in soil extract and root extracts of 2-, 4-, and 8-week-old oats, soybeans, and wheat. Population changes of Agrobacterium radiobacter, Arthrobacter citreus, Azotobacter chroococcum, Bacillus cereus, and a Pseudomonas sp. in pure and mixed culture were followed by plating on selective media. B. cereus and A. chroococcum grew poorly alone or in mixed culture in the extracts. In soil extract, A. citreus predominated over, or was nearly equal in number to, the Gram-negative forms (Pseudomonas and Agrobacterium). In root extracts, Pseudomonas sp. always predominated over A. citreus in mixed culture. A. radiobacter was inhibited in mature root extracts (8-week-old plants) although in pure culture it recovered after a period. An antagonistic effect of Pseudomonas sp. on A. chroococcum plated on nitrogen-free agar medium was found to be related to the kind of agar used.

scholarly journals Fluorescent Artificial Receptor-Based Membrane Assay (FARMA) for Spatiotemporally Resolved Monitoring of Biomembrane Permeability

2019 ◽  
Author(s):  
Frank Biedermann ◽  
Garima Ghale, Ghale ◽  
Andreas Hennig ◽  
Werner M. Nau
Keyword(s):  
High Throughput Screening ◽  
High Sensitivity ◽  
Point Of View ◽  
Phospholipid Bilayer ◽  
Label Free ◽  
Microscopy Imaging ◽  
Biophysical Models ◽  
Fundamental Point ◽  
Artificial Receptor ◽  
Microplate Reader

<p>The spatiotemporally resolved monitoring of membrane translocation, <i>e.g.,</i> of drugs or toxins, has been a long-standing goal. Herein, we introduce the fluorescent artificial receptor-based membrane assay (FARMA), a facile, label-free method. With FARMA, the permeation of more than hundred organic compounds (drugs, toxins, pesticides, neurotransmitters, peptides, etc.) through vesicular phospholipid bilayer membranes has been monitored in real time (µs-h time scale) and with high sensitivity (nM-µM concentration), affording permeability coefficients across an exceptionally large range from 10<sup>–9</sup>‑10<sup>–3</sup> cm s<sup>–1</sup>. From a fundamental point of view, FARMA constitutes a powerful tool to assess structure-permeability relationships and to test biophysical models for membrane passage. From an applied perspective, FARMA can be extended to high-throughput screening by adaption of the microplate reader format, to spatial monitoring of membrane permeation by microscopy imaging, and to the compartmentalized monitoring of enzymatic activity.<b></b></p>

scholarly journals On the Ability of Perfluorohexane Sulfonate (PFHxS) Bioaccumulation by Two Pseudomonas sp. Strains Isolated from PFAS-Contaminated Environmental Matrices

2020 ◽  
Vol 8 (1) ◽  
pp. 92 ◽  
Author(s):  
Alessandro Presentato ◽  
Silvia Lampis ◽  
Andrea Vantini ◽  
Flavio Manea ◽  
Francesca Daprà ◽  
...  
Keyword(s):  
Short Chain ◽  
Industrial Processes ◽  
Bacterial Cells ◽  
Pseudomonas Sp ◽  
Environmental Matrices ◽  
Synthetic Compounds ◽  
Physiological Conditions ◽  
End Products ◽  
Polyfluoroalkyl Substances ◽  
Thermal And Chemical Stability

PFASs (perfluoroalkyl and polyfluoroalkyl substances) are highly fluorinated, aliphatic, synthetic compounds with high thermal and chemical stability as well as unique amphiphilic properties which make them ingredients in a range of industrial processes. PFASs have attracted consideration due to their persistence, toxicity and bioaccumulation tendency in the environment. Recently, attention has begun to be addressed to shorter-chain PFASs, such as perfluorohexane sulfonate [PFHxS], apparently less toxic to and more easily eliminated from lab animals. However, short-chain PFASs represent end-products from the transformation of fluorotelomers whose biotic breakdown reactions have not been identified to date. This means that such emergent pollutants will tend to accumulate and persist in ecosystems. Since we are just learning about the interaction between short-chain PFASs and microorganisms, this study reports on the response to PFHxS of two Pseudomonas sp. strains isolated from environmental matrices contaminated by PFASs. The PFHxS bioaccumulation potential of these strains was unveiled by exploiting different physiological conditions as either axenic or mixed cultures under alkanothrofic settings. Moreover, electron microscopy revealed nonorthodox features of the bacterial cells, as a consequence of the stress caused by both organic solvents and PFHxS in the culturing substrate.

scholarly journals Yohkoh Observations of Coronal Structures Surrounding Dark Filaments

1998 ◽  
Vol 167 ◽  
pp. 163-170
Author(s):  
Yutaka Uchida
Keyword(s):  
Image Analysis ◽  
High Latitude ◽  
Dynamic Range ◽  
High Sensitivity ◽  
Event Structure ◽  
Point Of View ◽  
Coronal Structure ◽  
Wide Dynamic Range ◽  
Proper Understanding ◽  
Coronal Structures

AbstractWe describe in this paper some of the findings of the Yohkoh satellite about the coronal structure surrounding dark filaments in the pre-event and initial phases of high latitude arcade formation events. The knowledge of pre-event structure and its change is essential for the proper understanding of the arcade flaring process from the causality point of view. The wide dynamic range and high sensitivity obervations by Yohkoh allow us to look into the faint structures and their changes with the use of a faint-feature-enhancing technique in the image analysis.

scholarly journals Separation of Biological Entities from Human Blood by Using Magnetic Nanocomposites Obtained from Zeolite Precursors

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1803
Author(s):  
Serena Esposito ◽  
Antonello Marocco ◽  
Gianfranco Dell’Agli ◽  
Barbara Bonelli ◽  
Franca Mannu ◽  
...  
Keyword(s):  
Human Blood ◽  
Chemical Properties ◽  
Industrial Process ◽  
High Sensitivity ◽  
Point Of View ◽  
The Novel ◽  
Magnetic Adsorbents ◽  
Physico Chemical ◽  
Magnetic Metal ◽  
Biological Entities

In this work, three novel magnetic metal–ceramic nanocomposites were obtained by thermally treating Fe-exchanged zeolites (either A or X) under reducing atmosphere at relatively mild temperatures (750–800 °C). The so-obtained materials were thoroughly characterized from the point of view of their physico-chemical properties and, then, used as magnetic adsorbents in the separation of the target gene factors V and RNASE and of the Staphylococcus aureus bacteria DNA from human blood. Such results were compared with those obtained by using a top ranking commercial separation system (namely, SiMAG-N-DNA by Chemicell). The results obtained by using the novel magnetic adsorbents were similar to (or even better than) those obtained by using the commercial system, both during manual and automated separations, provided that a proper protocol was adopted. Particularly, the novel magnetic adsorbents showed high sensitivity during tests performed with small volumes of blood. Finally, the feasible production of such magnetic adsorbents by an industrial process was envisaged as well.

Catecholamine sulfates: End products or metabolic intermediates?

Life Sciences ◽  
1987 ◽  
Vol 40 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Sylvain Demassieux ◽  
Luc Bordeleau ◽  
Denis Gravel ◽  
Serge Carriére
Keyword(s):  
Metabolic Intermediates ◽  
End Products

The ROMY project: A 4-component ring laser for geophysics and geodesy

2020 ◽  
Author(s):  
Heiner Igel ◽  
Felix Bernauer ◽  
Joachim Wassermann ◽  
Shihao Yuan ◽  
Andre Gebauer ◽  
...  
Keyword(s):  
Ground Motion ◽  
Ring Laser ◽  
High Sensitivity ◽  
Point Of View ◽  
Small Scale ◽  
Broadband Seismometer ◽  
Rotational Ground Motion ◽  
Noise Characteristics ◽  
The Individual ◽  
Redundant Component

&lt;p&gt;The ROMY ring laser was constructed with 4 non-orthogonal triangular-shaped cavities of 12 m side length in the Geophysical Observatory outside Munich, Germany, in 2016. The large dimensions of the individual rings have the benefit of allowing high sensitivity surpassing in principle the sensitivity of the G-ring at the Fundamentalstation Wettzell. However, the concrete construction of ROMY is geometrically less stable than the G-ring that is built on a rigid Xerodur plate. Each of the four rings has its own Sagnac frequency. The horizontal triangular ring laser at the top of the inverted tetrahedral ROMY structure allows direct comparison of teleseismic signals and noise with the G-ring at a distance of 200km. It also serves as redundant component. In principle, three orthogonal components of rotational ground motion can be obtained by linear combination from any combination of three rings, that - due to the variable Sagnac frequency - have different noise characteristics. We report on the behavior and observations of ROMY from a seismological point of view. It is fair to say that ROMY provides the most accurate direct 3-component rotational ground motion seismic observations to date. In combination with a collocated broadband seismometer as well as a surrounding small-scale seismic array, we analyse regional, teleseismic events, and ocean-generated noise and compare with array-derived rotation.&lt;/p&gt;

Scope for growth versus actual growth in the juvenile predatory gastropod Chorus giganteus

2006 ◽  
Vol 86 (6) ◽  
pp. 1423-1428 ◽  
Author(s):  
J.M. Navarro ◽  
G.X. Urrutia ◽  
C. Carrasco
Keyword(s):  
Ingestion Rate ◽  
High Sensitivity ◽  
Point Of View ◽  
The Body ◽  
Experimental Conditions ◽  
Pronounced Increase ◽  
Continuous Increase ◽  
Scope For Growth ◽  
Physiological Variables ◽  
Actual Growth

The scope for growth (SFG) calculated on measurements of physiological variables in juvenile of the predatory gastropod Chorus giganteus was compared with the actual growth under an energetic point of view. The continuous increase in the amount of food ingested and absorbed by C. giganteus was clearly related to the body size of the snails. The pronounced increase in the metabolic processes of respiration and excretion at the end of the study was related with the high rates of growth experienced by the snails under the experimental conditions. These results were supported by the correlation analysis where ingestion rate (r=0.99), oxygen consumption (r=0.88) and excretion rate (r=0.89) were significantly correlated with the actual growth (P≤0.05). Comparing the estimated growth curve (SFG) with that directly measured on juvenile individuals of C. giganteus, a high similarity in results was observed. The high sensitivity of the scope for growth argues for the use of this index as an adequate tool for estimating the growth of juvenile gastropod molluscs without interference from reproductive processes such as gametogenesis and spawning which may produce corresponding rises and falls in the biomass of individuals. Scope for growth is thus validated as a reliable measurement of the physiological/energetic condition of the organism, representing an effective index for indirect estimation of the growth of a species.

scholarly journals Fungus Evaluation from Seeds Germplasm before Medium and Long Term Storage

2016 ◽  
Vol 49 (3) ◽  
pp. 71-82
Author(s):  
Domnica Daniela Plăcintă ◽  
Danela Murariu
Keyword(s):  
Agar Medium ◽  
Point Of View ◽  
Perennial Grasses ◽  
Paper Substrate ◽  
Fungal Parasite ◽  
Blotting Paper ◽  
Long Term Storage ◽  
Seed Health ◽  
Term Storage

Abstract During 2000-2016, 213 entries from 29 plant species from different crop groups (cereals, legumes, industrial crops, perennial grasses, vegetables, cucurbits, aromatic and medicinal plants) from core collection of the Suceava Genebank were evaluated from phytosanitary status point of view, before the storing. The seeds testing to the micromycetes incidence in the laboratory by incubating of them on blotting paper substrate and agar medium was performed. Fungal saprophytes from genus as: Alternaria spp., Stemphylium spp., Cladosporium sp., Rhyzopus sp., Epicocum sp., Aspergillus sp., Penicillium sp., Botrytis sp. occurred frequently in seeds samples of the tested crops. Also, 12 fungal parasite were isolated: Sclerospora sp., Diplodia sp., Nigrospora sp. on maize; Drechslera spp. on wheat, barley, rye and flax; Septoria sp. on barley; Fusarium spp. on maize, barley, rye, millet, bean, pea, flax, hemp, peppers, cucumbers; Colletotrichum spp. on maize, bean and faba bean; Sclerotinia sp., Isariopsis sp. and Rhyzoctonia sp. on bean; Verticillium sp. on peppers and okra, Ascochyta sp. on pea. The obtained results were expressed as percentage of the number of fungal isolated from tested samples species, highlighting the existing microflora and need to seed health testing with major importance in maintaing of high quality germplasm avoiding the pathogens preservation and dissemination.

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