Faculty Opinions recommendation of Bacterial response to spatial gradients of algal-derived nutrients in a porous microplate.

2021 ◽  
Author(s):  
Stefan Bertilsson ◽  
Maliheh Mehrshad
Keyword(s):  
Spatial Gradients ◽  
Bacterial Response

scholarly journals Bacterial response to spatial gradients of algal-derived nutrients in a porous microplate

2021 ◽  
Author(s):  
Hyungseok Kim ◽  
Jeffrey A. Kimbrel ◽  
Christopher A. Vaiana ◽  
Jessica R. Wollard ◽  
Xavier Mayali ◽  
...  
Keyword(s):  
Community Development ◽  
Spatial Proximity ◽  
Algal Culture ◽  
Physical Separation ◽  
Spatial Gradients ◽  
Bacterial Response ◽  
Algal Host ◽  
Metabolic Interactions ◽  
Culture Growth ◽  
Experimental Findings

AbstractPhotosynthetic microalgae are responsible for 50% of the global atmospheric CO2 fixation into organic matter and hold potential as a renewable bioenergy source. Their metabolic interactions with the surrounding microbial community (the algal microbiome) play critical roles in carbon cycling, but due to methodological limitations, it has been challenging to examine how community development is influenced by spatial proximity to their algal host. Here we introduce a copolymer-based porous microplate to co-culture algae and bacteria, where metabolites are constantly exchanged between the microorganisms while maintaining physical separation. In the microplate, we found that the diatom Phaeodactylum tricornutum accumulated to cell abundances ~20 fold higher than under normal batch conditions due to constant replenishment of nutrients through the porous structure. We also demonstrate that algal-associated bacteria, both single isolates and complex communities, responded to inorganic nutrients away from their host as well as organic nutrients originating from the algae in a spatially predictable manner. These experimental findings coupled with a mathematical model suggest that host proximity and algal culture growth phase impact bacterial community development in a taxon-specific manner through organic and inorganic nutrient availability. Our novel system presents a useful tool to investigate universal metabolic interactions between microbes in aquatic ecosystems.

scholarly journals Bacterial response to spatial gradients of algal-derived nutrients in a porous microplate

2021 ◽  
Author(s):  
Hyungseok Kim ◽  
Jeffrey A. Kimbrel ◽  
Christopher A. Vaiana ◽  
Jessica R. Wollard ◽  
Xavier Mayali ◽  
...  
Keyword(s):  
Spatial Proximity ◽  
Algal Culture ◽  
Physical Separation ◽  
Associated Bacteria ◽  
Spatial Gradients ◽  
Bacterial Response ◽  
Algal Host ◽  
Metabolic Interactions ◽  
Culture Growth ◽  
Experimental Findings

Photosynthetic microalgae are responsible for 50% of the global atmospheric CO2 fixation into organic matter and hold potential as a renewable bioenergy source. Their metabolic interactions with the surrounding microbial community (the algal microbiome) play critical roles in carbon cycling, but due to methodological limitations, it has been challenging to examine how community is developed by spatial proximity to their algal host. Here we introduce a hydrogel-based porous microplate to co-culture algae and bacteria, where metabolites are constantly exchanged between the microorganisms while maintaining physical separation. In the microplate we found that the diatom Phaeodactylum tricornutum accumulated to cell abundances ~20 fold higher than under normal batch conditions due to constant replenishment of nutrients through the hydrogel. We also demonstrate that algal-associated bacteria, both single isolates and complex communities, responded to inorganic nutrients away from their host as well as organic nutrients originating from the algae in a spatially predictable manner. These experimental findings coupled with a mathematical model suggest that host proximity and algal culture growth phase impact bacterial community development in a taxon-specific manner through organic and inorganic nutrient availability. Our novel system presents a useful tool to investigate universal metabolic interactions between microbes in aquatic ecosystems.

scholarly journals Effects of Dispersants and Biosurfactants on Crude-Oil Biodegradation and Bacterial Community Succession

2021 ◽  
Vol 9 (6) ◽  
pp. 1200
Author(s):  
Gareth E. Thomas ◽  
Jan L. Brant ◽  
Pablo Campo ◽  
Dave R. Clark ◽  
Frederic Coulon ◽  
...  
Keyword(s):  
Crude Oil ◽  
Early Stage ◽  
Niche Partitioning ◽  
Hydrocarbon Biodegradation ◽  
Hydrocarbonoclastic Bacteria ◽  
Bacterial Response ◽  
Oil Biodegradation ◽  
Interfacial Surface ◽  
Degrading Bacteria ◽  
Oil Spill Response

This study evaluated the effects of three commercial dispersants (Finasol OSR 52, Slickgone NS, Superdispersant 25) and three biosurfactants (rhamnolipid, trehalolipid, sophorolipid) in crude-oil seawater microcosms. We analysed the crucial early bacterial response (1 and 3 days). In contrast, most analyses miss this key period and instead focus on later time points after oil and dispersant addition. By focusing on the early stage, we show that dispersants and biosurfactants, which reduce the interfacial surface tension of oil and water, significantly increase the abundance of hydrocarbon-degrading bacteria, and the rate of hydrocarbon biodegradation, within 24 h. A succession of obligate hydrocarbonoclastic bacteria (OHCB), driven by metabolite niche partitioning, is demonstrated. Importantly, this succession has revealed how the OHCB Oleispira, hitherto considered to be a psychrophile, can dominate in the early stages of oil-spill response (1 and 3 days), outcompeting all other OHCB, at the relatively high temperature of 16 °C. Additionally, we demonstrate how some dispersants or biosurfactants can select for specific bacterial genera, especially the biosurfactant rhamnolipid, which appears to provide an advantageous compatibility with Pseudomonas, a genus in which some species synthesize rhamnolipid in the presence of hydrocarbons.

scholarly journals Novel approach for quantification of multiple immunofluorescent signals using histograms and 2D plot profiling of whole-section panoramic images

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Roko Duplancic ◽  
Darko Kero
Keyword(s):  
Histological Section ◽  
Cell Counting ◽  
Tissue Samples ◽  
Spatial Gradients ◽  
Multiple Markers ◽  
Novel Approach ◽  
Academic Settings ◽  
Panoramic Images ◽  
Multiple Regions ◽  
Staining Protocol

AbstractWe describe a novel approach for quantification and colocalization of immunofluorescence (IF) signals of multiple markers on high-resolution panoramic images of serial histological sections utilizing standard staining techniques and readily available software for image processing and analysis. Human gingiva samples stained with primary antibodies against the common leukocyte antigen CD45 and factors related to heparan sulfate glycosaminoglycans (HS GAG) were used. Expression domains and spatial gradients of IF signals were quantified by histograms and 2D plot profiles, respectively. The importance of histomorphometric profiling of tissue samples and IF signal thresholding is elaborated. This approach to quantification of IF staining utilizes pixel (px) counts and comparison of px grey value (GV) or luminance. No cell counting is applied either to determine the cellular content of a given histological section nor the number of cells positive to the primary antibody of interest. There is no selection of multiple Regions-Of-Interest (ROIs) since the entire histological section is quantified. Although the standard IF staining protocol is applied, the data output enables colocalization of multiple markers (up to 30) from a given histological sample. This can serve as an alternative for colocalization of IF staining of multiple primary antibodies based on repeating cycles of staining of the same histological section since those techniques require non standard staining protocols and sophisticated equipment that can be out of reach for small laboratories in academic settings. Combined with the data from ontological bases, this approach to quantification of IF enables creation of in silico virtual disease models.

Call variation of Crested Francolin ( Dendroperdix sephaena ) across Africa defies the effects of spatial gradients

Ibis ◽  
2021 ◽  
Author(s):  
Johann H. Van Niekerk ◽  
Rodrigo Megía‐Palma ◽  
Giovanni Forcina
Keyword(s):  
Spatial Gradients

scholarly journals Reconstruction of Microscopic Thermal Fields from Oversampled Infrared Images in Laser-Based Powder Bed Fusion

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4859
Author(s):  
Leigh Stanger ◽  
Thomas Rockett ◽  
Alistair Lyle ◽  
Matthew Davies ◽  
Magnus Anderson ◽  
...  
Keyword(s):  
Transfer Function ◽  
Measured Signal ◽  
Powder Bed Fusion ◽  
Validation Data ◽  
Powder Bed ◽  
Spatial Gradients ◽  
Microstructure Modeling ◽  
Thermal Fields ◽  
Significant Difference ◽  
Spatial Transfer Function

This article elucidates the need to consider the inherent spatial transfer function (blur), of any thermographic instrument used to measure thermal fields. Infrared thermographic data were acquired from a modified, commercial, laser-based powder bed fusion printer. A validated methodology was used to correct for spatial transfer function errors in the measured thermal fields. The methodology was found to make a difference of 40% to the measured signal levels and a 174 °C difference to the calculated effective temperature. The spatial gradients in the processed thermal fields were found to increase significantly. These corrections make a significant difference to the accuracy of validation data for process and microstructure modeling. We demonstrate the need for consideration of image blur when quantifying the thermal fields in laser-based powder bed fusion in this work.

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