scholarly journals Final Report (DE-SC0013887): The transparent soil microcosm: a window into the spatial distribution and dynamics of carbon utilization and microbial interspecies interactions

2021 ◽  
Author(s):  
Elizabeth Shank
Keyword(s):  
Spatial Distribution ◽  
Soil Microcosm ◽  
Final Report ◽  
Interspecies Interactions ◽  
Carbon Utilization ◽  
Transparent Soil

scholarly journals Dynamics of Heterotrophic Bacterial Assemblages withinSynechococcusCultures

2017 ◽  
Vol 84 (3) ◽  
Author(s):  
Qiang Zheng ◽  
Yu Wang ◽  
Rui Xie ◽  
Andrew S. Lang ◽  
Yanting Liu ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Heterotrophic Bacteria ◽  
Biogeochemical Cycling ◽  
Distribution Patterns ◽  
Culture Period ◽  
Interspecies Interactions ◽  
Carbon Utilization ◽  
Free Living ◽  
Content Type ◽  
Culture Growth

ABSTRACTInteractions between photoautotrophic and heterotrophic microorganisms are central to the marine microbial ecosystem. Lab cultures of one of the dominant marine photoautotrophs,Synechococcus, have historically been difficult to render axenic, presumably because these bacteria depend upon other organisms to grow under these conditions. These tight associations betweenSynechococcusand heterotrophic bacteria represent a good relevant system to study interspecies interactions. Ten individualSynechococcusstrains, isolated from eutrophic and oligotrophic waters, were chosen for investigation. Four to six dominant associated heterotrophic bacteria were detected in the liquid cultures of eachSynechococcusisolate, comprising members of theCytophaga-Flavobacteria-Bacteroides(CFB) group (mainly fromFlavobacterialesandCytophagales),Alphaproteobacteria(mainly from theRoseobacterclade),Gammaproteobacteria(mainly from theAlteromonadalesandPseudomonadales), andActinobacteria. The presence of the CFB group,Gammaproteobacteria, andActinobacteriashowed clear geographic patterns related to the isolation environments of theSynechococcusbacteria. An investigation of the population dynamics within a growing culture (XM-24) of one of the isolates, including an evaluation of the proportions of cells that were free-living versus aggregated/attached, revealed interesting patterns for different bacterial groups. InSynechococcussp. strain XM-24 culture, flavobacteria, which was the most abundant group throughout the culture period, tended to be aggregated or attached to theSynechococcuscells, whereas the actinobacteria demonstrated a free-living lifestyle, and roseobacters displayed different patterns depending on the culture growth phase. Factors contributing to these succession patterns for the heterotrophs likely include interactions among the culture community members, their relative abilities to utilize different compounds produced bySynechococcuscells and changes in the compounds released as culture growth proceeds, and their responses to other changes in the environmental conditions throughout the culture period.IMPORTANCEMarine microbes exist within an interactive ecological network, and studying their interactions is an important part of understanding their roles in global biogeochemical cycling and the determinants of microbial diversity. In this study, the dynamic relationships betweenSynechococcusspp. and their associated heterotrophic bacteria were investigated.Synechococcus-associated heterotrophic bacteria had similar geographic distribution patterns as their “host” and displayed different lifestyles (free-living versus attached/aggregated) according to theSynechococcusculture growth phases. Combined organic carbon composition and bacterial lifestyle data indicated a potential for succession in carbon utilization patterns by the dominant associated heterotrophic bacteria. Comprehending the interactions between photoautotrophs and heterotrophs and the patterns of organic carbon excretion and utilization is critical to understanding their roles in oceanic biogeochemical cycling.

scholarly journals Interspecies interactions in bacterial colonies are determined by physiological traits and the environment

2019 ◽  
Author(s):  
Sean C. Booth ◽  
Scott A. Rice
Keyword(s):  
Spatial Distribution ◽  
Community Composition ◽  
Environmental Parameters ◽  
Interspecies Interactions ◽  
Type Iv ◽  
Biophysical Forces ◽  
Agar Surface ◽  
Engineered Systems ◽  
Specific Species ◽  
And Function

AbstractInterspecies interactions in bacterial biofilms have important impacts on the composition and function of communities in natural and engineered systems. To investigate these interactions, synthetic communities provide experimentally tractable systems. Agar-surface colonies are similar to biofilms and have been used for investigating the eco-evolutionary and biophysical forces that determine community composition and spatial distribution of bacteria. Prior work has focused on intraspecies interactions, using differently fluorescent tagged but identical or genetically modified strains of the same species. Here, we investigated how physiological differences determine the community composition and spatial distribution in synthetic communities of Pseudomonas aeruginosa, Pseudomonas protegens and Klebsiella pneumoniae. Using quantitative microscopic imaging, we found that interspecies interactions in multispecies colonies are influenced by type IV pilus mediated motility, extracellular matrix secretion, environmental parameters and the specific species involved. These results indicate that the patterns observable in mixed species colonies can be used to understand the mechanisms that drive interspecies interactions, which are dependent on the interplay between specific species’ physiology and environmental conditions.

Lithography below 100 nm

1983 ◽  
Vol 41 ◽  
pp. 96-99
Author(s):  
L. D. Jackel
Keyword(s):  
Spatial Distribution ◽  
Electron Beam ◽  
Electron Scattering ◽  
Electron Beam Lithography ◽  
Substrate Material ◽  
Local Electron ◽  
Electron Dose ◽  
Positive Resist ◽  
Exposure Process

Most production electron beam lithography systems can pattern minimum features a few tenths of a micron across. Linewidth in these systems is usually limited by the quality of the exposing beam and by electron scattering in the resist and substrate. By using a smaller spot along with exposure techniques that minimize scattering and its effects, laboratory e-beam lithography systems can now make features hundredths of a micron wide on standard substrate material. This talk will outline sane of these high- resolution e-beam lithography techniques.We first consider parameters of the exposure process that limit resolution in organic resists. For concreteness suppose that we have a “positive” resist in which exposing electrons break bonds in the resist molecules thus increasing the exposed resist's solubility in a developer. Ihe attainable resolution is obviously limited by the overall width of the exposing beam, but the spatial distribution of the beam intensity, the beam “profile” , also contributes to the resolution. Depending on the local electron dose, more or less resist bonds are broken resulting in slower or faster dissolution in the developer.

SEM evaluation of the TEM cold-stage double-film specimen

1984 ◽  
Vol 42 ◽  
pp. 272-273
Author(s):  
Jayesh Bellare
Keyword(s):  
Spatial Distribution ◽  
Sample Preparation ◽  
Sample Thickness ◽  
Specimen Preparation ◽  
Preparation Technique ◽  
Liquid Sample ◽  
Thin Specimen ◽  
Sample Preparation Technique ◽  
Cold Stage ◽  
Film Specimen

Seeing is believing, but only after the sample preparation technique has received a systematic study and a full record is made of the treatment the sample gets.For microstructured liquids and suspensions, fast-freeze thermal fixation and cold-stage microscopy is perhaps the least artifact-laden technique. In the double-film specimen preparation technique, a layer of liquid sample is trapped between 100- and 400-mesh polymer (polyimide, PI) coated grids. Blotting against filter paper drains excess liquid and provides a thin specimen, which is fast-frozen by plunging into liquid nitrogen. This frozen sandwich (Fig. 1) is mounted in a cooling holder and viewed in TEM.Though extremely promising for visualization of liquid microstructures, this double-film technique suffers from a) ireproducibility and nonuniformity of sample thickness, b) low yield of imageable grid squares and c) nonuniform spatial distribution of particulates, which results in fewer being imaged.

Macroprobe Mode for the Study of Segregation in Steels

1990 ◽  
Vol 48 (2) ◽  
pp. 260-261
Author(s):  
Auclair Gilles ◽  
Benoit Danièle
Keyword(s):  
Mechanical Properties ◽  
Spatial Distribution ◽  
High Performance ◽  
Volume Fraction ◽  
Sheet Steel ◽  
Acquisition Time ◽  
Chemical Information ◽  
X Ray ◽  
Accurate Quantitative Analysis ◽  
Optical Micrographs

During these last 10 years, high performance correction procedures have been developed for classical EPMA, and it is nowadays possible to obtain accurate quantitative analysis even for soft X-ray radiations. It is also possible to perform EPMA by adapting this accurate quantitative procedures to unusual applications such as the measurement of the segregation on wide areas in as-cast and sheet steel products.The main objection for analysis of segregation in steel by means of a line-scan mode is that it requires a very heavy sampling plan to make sure that the most significant points are analyzed. Moreover only local chemical information is obtained whereas mechanical properties are also dependant on the volume fraction and the spatial distribution of highly segregated zones. For these reasons we have chosen to systematically acquire X-ray calibrated mappings which give pictures similar to optical micrographs. Although mapping requires lengthy acquisition time there is a corresponding increase in the information given by image anlysis.

Ultrastructural analysis of the spatial distribution of MRNA

1992 ◽  
Vol 50 (1) ◽  
pp. 552-553
Author(s):  
Gary Bassell ◽  
Robert H. Singer
Keyword(s):  
Electron Microscopy ◽  
Spatial Distribution ◽  
In Situ Hybridization ◽  
High Resolution ◽  
Nucleic Acids ◽  
Colloidal Gold ◽  
Dna Probe ◽  
Nucleotide Analogs ◽  
Gold Particles

We have been investigating the spatial distribution of nucleic acids intracellularly using in situ hybridization. The use of non-isotopic nucleotide analogs incorporated into the DNA probe allows the detection of the probe at its site of hybridization within the cell. This approach therefore is compatible with the high resolution available by electron microscopy. Biotinated or digoxigenated probe can be detected by antibodies conjugated to colloidal gold. Because mRNA serves as a template for the probe fragments, the colloidal gold particles are detected as arrays which allow it to be unequivocally distinguished from background.

Membrane microdomains: lessons from microscopy

1995 ◽  
Vol 53 ◽  
pp. 776-777
Author(s):  
J.M. Robinson ◽  
J.M Oliver
Keyword(s):  
Spatial Distribution ◽  
Plasma Membrane ◽  
Epithelial Cells ◽  
Plasma Membranes ◽  
Cell Types ◽  
Imaging Modalities ◽  
Membrane Microdomains ◽  
Membrane Domains ◽  
Lateral Heterogeneity ◽  
Functional Importance

Specialized regions of plasma membranes displaying lateral heterogeneity are the focus of this Symposium. Specialized membrane domains are known for certain cell types such as differentiated epithelial cells where lateral heterogeneity in lipids and proteins exists between the apical and basolateral portions of the plasma membrane. Lateral heterogeneity and the presence of microdomains in membranes that are uniform in appearance have been more difficult to establish. Nonetheless a number of studies have provided evidence for membrane microdomains and indicated a functional importance for these structures.This symposium will focus on the use of various imaging modalities and related approaches to define membrane microdomains in a number of cell types. The importance of existing as well as emerging imaging technologies for use in the elucidation of membrane microdomains will be highlighted. The organization of membrane microdomains in terms of dimensions and spatial distribution is of considerable interest and will be addressed in this Symposium.

Sign in / Sign up

Export Citation Format

Share Document