scholarly journals Biofilm Growth Under Elastic Confinement

2021 ◽  
Author(s):  
George T. Fortune ◽  
Nuno M. Oliveira ◽  
Raymond E. Goldstein
Keyword(s):  
Radial Growth ◽  
Solid Surfaces ◽  
Radial Growth Rate ◽  
Confined Geometries ◽  
Biofilm Growth ◽  
Confined Spaces ◽  
Quantitative Studies ◽  
The Matrix ◽  
Self Similar ◽  
Semi Solid

AbstractBacteria often form surface-bound communities, embedded in a self-produced extracellular matrix, called biofilms. Quantitative studies of their growth have typically focused on unconfined expansion above solid or semi-solid surfaces, leading to exponential radial growth. This geometry does not accurately reflect the natural or biomedical contexts in which biofilms grow in confined spaces. Here we consider one of the simplest confined geometries: a biofilm growing laterally in the space between a solid surface and an overlying elastic sheet. A poroelastic framework is utilised to derive the radial growth rate of the biofilm; it reveals an additional self-similar expansion regime, governed by the stiffness of the matrix, leading to a finite maximum radius, consistent with our experimental observations of growing Bacillus subtilis biofilms confined by PDMS.

 The Effect of a Pine Looper Moth Outbreak on the Radial Growth Rate of Pine

2020 ◽  
Vol 13 (7) ◽  
pp. 754-760
Author(s):  
V. G. Soukhovolsky ◽  
P. A. Krasnoperova ◽  
E. N. Pal’nikova ◽  
I. V. Sviderskaya ◽  
O. V. Tarasova
Keyword(s):  
Growth Rate ◽  
Radial Growth ◽  
Radial Growth Rate

GrowFruit: An IoT based Radial Growth Rate Monitoring Device for Fruit

2021 ◽  
pp. 1-1
Author(s):  
Anirbit Sengupta ◽  
Anwesha Mukherjee ◽  
Abhijit Das ◽  
Debashis De
Keyword(s):  
Growth Rate ◽  
Radial Growth ◽  
Monitoring Device ◽  
Radial Growth Rate

scholarly journals Unique inducible filamentous motility identified in pathogenic Bacillus cereus group species

2020 ◽  
Vol 14 (12) ◽  
pp. 2997-3010
Author(s):  
Martha M. Liu ◽  
Shannon Coleman ◽  
Lauren Wilkinson ◽  
Maren L. Smith ◽  
Thomas Hoang ◽  
...  
Keyword(s):  
Bacterial Biomass ◽  
Solid Surfaces ◽  
Ecological Significance ◽  
Rna Seq ◽  
Bacillus Cereus Group ◽  
Control Rod ◽  
Surface Motility ◽  
Semi Solid ◽  
Membrane Components ◽  
Group Species

Abstract Active migration across semi-solid surfaces is important for bacterial success by facilitating colonization of unoccupied niches and is often associated with altered virulence and antibiotic resistance profiles. We isolated an atmospheric contaminant, subsequently identified as a new strain of Bacillus mobilis, which showed a unique, robust, rapid, and inducible filamentous surface motility. This flagella-independent migration was characterized by formation of elongated cells at the expanding edge and was induced when cells were inoculated onto lawns of metabolically inactive Campylobacter jejuni cells, autoclaved bacterial biomass, adsorbed milk, and adsorbed blood atop hard agar plates. Phosphatidylcholine (PC), bacterial membrane components, and sterile human fecal extracts were also sufficient to induce filamentous expansion. Screening of eight other Bacillus spp. showed that filamentous motility was conserved amongst B. cereus group species to varying degrees. RNA-Seq of elongated expanding cells collected from adsorbed milk and PC lawns versus control rod-shaped cells revealed dysregulation of genes involved in metabolism and membrane transport, sporulation, quorum sensing, antibiotic synthesis, and virulence (e.g., hblA/B/C/D and plcR). These findings characterize the robustness and ecological significance of filamentous surface motility in B. cereus group species and lay the foundation for understanding the biological role it may play during environment and host colonization.

316L Stainless Steel Sensitization in Carbon Nanotube CVD Growth for Bacterial Resistance

2020 ◽  
Author(s):  
Sterling Voss ◽  
Bret Mecham ◽  
Lucy Bowden ◽  
Jacquelyn Monroe ◽  
Anton E. Bowden ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Stainless Steel ◽  
Chromium Carbide ◽  
316L Stainless Steel ◽  
Bacterial Resistance ◽  
Chemical Vapor ◽  
Deposition Process ◽  
Carbide Formation ◽  
Biofilm Growth ◽  
The Matrix

Abstract Physically altering the micro-topography of a surface can dramatically affect its capacity to support or prevent biofilm growth. Growing carbon-infiltrated carbon nanotubes on biomedical materials is one such approach which has proven effective. Unfortunately, the high temperature and carbon-rich gas exposure required for this procedure has proven to have deleterious effects. This paper proposes a kinetic model to explain the rusting phenomenon observed on 316L stainless steel substrates which have undergone the chemical vapor deposition process to grow carbon-infiltrated carbon nanotubes. The model is derived from Fick’s Second Law, and predicts the growth of chromium carbide as a function of temperature and time. Chromium carbide formation is shown to be the mechanism of corrosion, as chromium atoms are leeched from the the matrix, preventing the formation of a passivating chromium oxide layer in place of problematic iron oxide (rust) formation. The model is validated using experimental methods, which involve immersion in bacteria culture, scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDX).

Continuous radial growth rate monitoring of horticultural crops using an optical mouse

2019 ◽  
Vol 297 ◽  
pp. 111526
Author(s):  
Subir Das ◽  
Shikha Nayak ◽  
Badal Chakraborty ◽  
Sabyasachi Mitra
Keyword(s):  
Growth Rate ◽  
Radial Growth ◽  
Radial Growth Rate ◽  
Horticultural Crops ◽  
Optical Mouse

Enhanced erosion resistance of biopolymer-enriched B. subtilis NCIB 3610 biofilms

2020 ◽  
Author(s):  
Elif Nur Hayta ◽  
Oliver Lieleg
Keyword(s):  
Erosion Resistance ◽  
Biotechnological Applications ◽  
Shear Forces ◽  
Cavity Depth ◽  
Biofilm Growth ◽  
Promising Strategy ◽  
The Matrix ◽  
Rose Petal ◽  
Surface Superhydrophobicity ◽  
High Erosion Resistance

<p>Erosion resistance is one of the advantages bacteria gain by producing biofilms. While it is undesirable for us humans when biofilms grow on medical devices or industrial pipelines, biofilms with a high erosion resistance can be advantageous for biotechnological applications. Here, we demonstrate how the erosion resistance of <em>B. subtilis</em> NCIB 3610 biofilms can be enhanced by integrating foreign (bio)polymers such as γ-polyglutamate (PGA), alginate and polyethylene glycol (PEG) into the matrix during biofilm growth.<br /><br />Artificial enrichment of the NCIB 3610 biofilms with these biopolymers causes a significant increase in the erosion resistance by slightly changing the surface topography: A decreased cavity depth on the surface results in an alteration in the mode of surface superhydrophobicity, and we obtain a state that is located somewhere between rose-petal like and lotus-like wetting resistance. Surprisingly, the viscoelastic and microscopic penetration properties of the biofilms are not affected by the artificial incorporation of (bio)polymers. As we obtained similar results with all the biopolymers tested (which differ in terms of charge and molecular weight), this indicates that a variety of different (bio)polymers can be employed for a similar purpose.<br /><br />The method introduced here may present a promising strategy for engineering beneficial biofilms such, that they become more stable towards shear forces caused by flowing water but, at the same time, remain permeable to nutrients or other molecules.</p>

Average radial growth rate and chlamydospore production of Ceratocystis minor, Ceratocystis minor var. barrasii, and SJB 122 in culture

1989 ◽  
Vol 67 (12) ◽  
pp. 3498-3505 ◽  
Author(s):  
David S. Goldhammer ◽  
Frederick M. Stephen ◽  
Timothy D. Paine
Keyword(s):  
Growth Rate ◽  
Uric Acid ◽  
Loblolly Pine ◽  
Radial Growth ◽  
Dendroctonus Frontalis ◽  
Radial Growth Rate ◽  
Acid Media ◽  
Low Concentrations ◽  
Pinus Taeda L ◽  
Ceratocystis Minor

Two symbiotic fungi (SJB 122, an unidentified basidiomycete, and Ceratocystis minor (Hedgecock) Hunt variety barrasii Taylor) and one pathogenic phoretic fungus (C. minor (Hedgecock) Hunt variety minor) of the southern pine beetle, Dendroctonus frontalis Zimmermann, were inoculated onto six different concentrations of D. frontalis frass, loblolly pine (Pinus taeda L.) phloem, and uric acid media to observe radial growth rates and chlamydospore production. The average radial growth rate per day of C. minor var. barrasii increased significantly from the control on all three media, but growth was faster at increased concentrations of added phloem compared with the other supplemented media. Significant increases in chlamydospores produced by C. minor var. barrasii from the control occurred only on frass media, with more chlamydospores being produced at higher concentrations. The average radial growth rate per day of SJB 122 fungus increased significantly from the control on only one concentration of phloem and two concentrations of uric acid, but decreased significantly on low concentrations of frass media. SJB 122 chlamydospore production increased with increasing concentration on frass, was not different from the control on phloem, and increased significantly at intermediate concentrations on uric acid. Ceratocystis minor var. minor average radial growth rate per day increased with increasing concentration on both frass and phloem media but on uric acid decreased significantly at higher concentrations, following an initial signficant increase as compared with the controls.

The Time Cone method for Nucleation and Growth Kinetics on a Finite Domain

1995 ◽  
Vol 398 ◽  
Author(s):  
John W. Cahn
Keyword(s):  
Growth Rate ◽  
Radial Growth ◽  
Nucleation And Growth ◽  
Time Dependent ◽  
Finite Domain ◽  
Radial Growth Rate ◽  
Transformation Kinetics ◽  
Statistical Solution ◽  
Closed Form Solutions ◽  
Growth Reaction

ABSTRACTThe Kolmogorov-Johnson-Mehl-Avrami theory is an exact statistical solution for the expected fraction transformed in a nucleation and growth reaction in an infinite specimen, when nucleation is random in the untransformed volume and the radial growth rate after nucleation is constant until impingement. Many of these restrictive assumptions are introduced to facilitate the use of statistics. The introduction of “phantom nuclei” and “extended volumes” are constructs that permit exact estimates of the fraction transformed. An alternative, the time cone method, is presented that does not make use of either of these constructs. The method permits obtaining exact closed form solutions for any specimen that is convex in time and space, and for nucleation rates and growth rates that are both time and position dependent. Certain types of growth anisotropies can be included. The expected fraction transformed is position and time dependent. Expressions for transformation kinetics in simple specimen geometries such as plates and growing films are given, and are shown to reduce to expected formulas in certain limits.

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