scholarly journals Mechanical forces drive a reorientation cascade leading to biofilm self-patterning

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Japinder Nijjer ◽  
Changhao Li ◽  
Qiuting Zhang ◽  
Haoran Lu ◽  
Sulin Zhang ◽  
...  
Keyword(s):  
Driving Forces ◽  
Orientational Order ◽  
Bacterial Cells ◽  
Active Matter ◽  
Differential Growth ◽  
Two Phase ◽  
Agent Based ◽  
Compressive Stresses ◽  
Cell Reorientation ◽  
Biofilm Development

AbstractIn growing active matter systems, a large collection of engineered or living autonomous units metabolize free energy and create order at different length scales as they proliferate and migrate collectively. One such example is bacterial biofilms, surface-attached aggregates of bacterial cells embedded in an extracellular matrix that can exhibit community-scale orientational order. However, how bacterial growth coordinates with cell-surface interactions to create distinctive, long-range order during biofilm development remains elusive. Here we report a collective cell reorientation cascade in growing Vibrio cholerae biofilms that leads to a differentially ordered, spatiotemporally coupled core-rim structure reminiscent of a blooming aster. Cell verticalization in the core leads to a pattern of differential growth that drives radial alignment of the cells in the rim, while the growing rim generates compressive stresses that expand the verticalized core. Such self-patterning disappears in nonadherent mutants but can be restored through opto-manipulation of growth. Agent-based simulations and two-phase active nematic modeling jointly reveal the strong interdependence of the driving forces underlying the differential ordering. Our findings offer insight into the developmental processes that shape bacterial communities and provide ways to engineer phenotypes and functions in living active matter.

scholarly journals Biofilm self-patterning: mechanical force landscaping drives a collective reorientation cascade

2021 ◽  
Author(s):  
Japinder Nijjer ◽  
Changhao Li ◽  
Qiuting Zhang ◽  
Haoran Lu ◽  
Sulin Zhang ◽  
...  
Keyword(s):  
Long Range ◽  
Bacterial Communities ◽  
Cell Imaging ◽  
Orientational Order ◽  
Two Phase ◽  
Agent Based ◽  
The Core ◽  
Complex Interactions ◽  
Single Cell Imaging ◽  
Orientational Ordering

During development, cells often self-organize into distinctive patterns with long-range orientational order. However, the mechanism by which long-range order emerges through complex interactions, particularly in the prokaryotic domain, remains elusive. Here we report, in growing Vibrio cholerae biofilms, a reorientation cascade consisting of cell verticalization in the core and radial alignment in the rim, generating a pattern reminiscent of a blooming aster. Single-cell imaging combined with agent-based simulations reveal that cell verticalization and radial alignment are spatiotemporally coupled, each generating the driving force for the other, to cause a dynamic cascade of differential orientational ordering. Such self-patterning is absent in nonadherent mutants but can be restored through opto-manipulation of growth. A two-phase active nematic model is developed to elucidate the mechanism underlying biofilm self-patterning, which offers insights into the control of organization in complex bacterial communities.

scholarly journals Revealing the Metabolic Alterations during Biofilm Development of Burkholderia cenocepacia Based on Genome-Scale Metabolic Modeling

Metabolites ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 221
Author(s):  
Ozlem Altay ◽  
Cheng Zhang ◽  
Hasan Turkez ◽  
Jens Nielsen ◽  
Mathias Uhlén ◽  
...  
Keyword(s):  
Systems Biology ◽  
Alternative Pathway ◽  
Growth Conditions ◽  
Pentose Phosphate ◽  
Burkholderia Cenocepacia ◽  
Bacterial Cells ◽  
Metabolic Remodeling ◽  
Transcriptomics Data ◽  
Biofilm Development ◽  
Genome Scale

Burkholderia cenocepacia is among the important pathogens isolated from cystic fibrosis (CF) patients. It has attracted considerable attention because of its capacity to evade host immune defenses during chronic infection. Advances in systems biology methodologies have led to the emergence of methods that integrate experimental transcriptomics data and genome-scale metabolic models (GEMs). Here, we integrated transcriptomics data of bacterial cells grown on exponential and biofilm conditions into a manually curated GEM of B. cenocepacia. We observed substantial differences in pathway response to different growth conditions and alternative pathway susceptibility to extracellular nutrient availability. For instance, we found that blockage of the reactions was vital through the lipid biosynthesis pathways in the exponential phase and the absence of microenvironmental lysine and tryptophan are essential for survival. During biofilm development, bacteria mostly had conserved lipid metabolism but altered pathway activities associated with several amino acids and pentose phosphate pathways. Furthermore, conversion of serine to pyruvate and 2,5-dioxopentanoate synthesis are also identified as potential targets for metabolic remodeling during biofilm development. Altogether, our integrative systems biology analysis revealed the interactions between the bacteria and its microenvironment and enabled the discovery of antimicrobial targets for biofilm-related diseases.

scholarly journals 616 Preventing Biofilms on BACTIGON® Coated Camstent Urinary Catheters in Patients Undergoing Elective Colorectal Surgery: A Single Centre Pilot Study

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
C Lewis-Lloyd ◽  
J Dubern ◽  
K Kalenderski ◽  
N Halliday ◽  
M Alexander ◽  
...  
Keyword(s):  
Environmental Scanning Electron Microscopy ◽  
Environmental Scanning ◽  
Bacterial Cells ◽  
Urinary Catheters ◽  
Elective Colorectal Surgery ◽  
Mineral Compositions ◽  
Microscopy Data ◽  
Tract Infections ◽  
Biofilm Development ◽  
Hospital Acquired

Abstract Introduction Catheter associated urinary tract infections account for 40% of hospital acquired infections. They are associated with biofilms consisting of bacterial cells enmeshed in a self-generated extracellular matrix adhering to catheter surfaces. We have developed a novel polymer family that, coated onto urinary catheters, creates a “non-stick” surface preventing biofilm development. Method Prospective cohort of elective colorectal patients recruited pre-operatively, received a standard silicone (SS) or Camstent (BACTIGON®) coated urinary catheter. After removal, catheters were cut longitudinally into 3 segments. Biomass and biomineralisation were analysed using confocal fluorescence microscopy. Data were normalised by square rooting the catheter indwelling duration. Environmental scanning electron microscopy and energy dispersive x-ray spectroscopy was performed. Results Of 40 patients, 20 each received a SS or coated catheter. Between SS and coated catheters, average indwelling duration was similar and biofilm biomass was 32.068µg/cm2 (95%CI ±21.950) vs. 1.948µg/cm2 (95%CI ±2.595) (P = 0.0111). Confocal microscopy suggested a 93.93% reduction in biofilm biomass on coated catheters. Mineral compositions were different with biofilm and struvite/apatite on SS and calcium oxalate, endogenously derived, on coated catheters. Conclusions Inert BACTIGON® coated catheters appear superior at preventing biofilm formation than SS catheters. Clinical trials are needed to determine the clinical and health economic benefit of this intervention.

scholarly journals Recent Advances in Surface Nanoengineering for Biofilm Prevention and Control. Part I: Molecular Basis of Biofilm Recalcitrance. Passive Anti-Biofouling Nanocoatings

Nanomaterials ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 1230 ◽  
Author(s):  
Paul Cătălin Balaure ◽  
Alexandru Mihai Grumezescu
Keyword(s):  
Life Cycle ◽  
Molecular Mechanisms ◽  
Antimicrobial Agents ◽  
Current Knowledge ◽  
Emergent Properties ◽  
Bacterial Cells ◽  
Life Cycle Stages ◽  
Fouling Release ◽  
Biofilm Development ◽  
And Control

Medical device-associated infections are becoming a leading cause of morbidity and mortality worldwide, prompting researchers to find new, more effective ways to control the bacterial colonisation of surfaces and biofilm development. Bacteria in biofilms exhibit a set of “emergent properties”, meaning those properties that are not predictable from the study of free-living bacterial cells. The social coordinated behaviour in the biofilm lifestyle involves intricate signaling pathways and molecular mechanisms underlying the gain in resistance and tolerance (recalcitrance) towards antimicrobial agents as compared to free-floating bacteria. Nanotechnology provides powerful tools to disrupt the processes responsible for recalcitrance development in all stages of the biofilm life cycle. The present paper is a state-of-the-art review of the surface nanoengineering strategies currently used to design antibiofilm coatings. The review is structurally organised in two parts according to the targeted biofilm life cycle stages and molecular mechanisms intervening in recalcitrance development. Therefore, in the present first part, we begin with a presentation of the current knowledge of the molecular mechanisms responsible for increased recalcitrance that have to be disrupted. Further, we deal with passive surface nanoengineering strategies that aim to prevent bacterial cells from settling onto a biotic or abiotic surface. Both “fouling-resistant” and “fouling release” strategies are addressed as well as their synergic combination in a single unique nanoplatform.

Contribution of different chemical groups to the driving forces for the partition of phenylmethane dyes in the PEO1500 + MgSO4 + H2O aqueous two-phase system

2020 ◽  
Vol 508 ◽  
pp. 112451
Author(s):  
Elkin Dario C. Castrillon ◽  
Yara L. Coelho ◽  
Álvaro Javier P. Agudelo ◽  
Isabela A. Marques ◽  
Eliara A. Hudson ◽  
...  
Keyword(s):  
Driving Forces ◽  
Phase System ◽  
Two Phase ◽  
Aqueous Two Phase System ◽  
Chemical Groups

scholarly journals Clove Oil (Syzygium aromaticum L.) Activity against Alicyclobacillus acidoterrestris Biofilm on Technical Surfaces

Molecules ◽  
2020 ◽  
Vol 25 (15) ◽  
pp. 3334
Author(s):  
Alina Kunicka-Styczyńska ◽  
Agnieszka Tyfa ◽  
Dariusz Laskowski ◽  
Aleksandra Plucińska ◽  
Katarzyna Rajkowska ◽  
...  
Keyword(s):  
Essential Oil ◽  
Culture Conditions ◽  
Plate Count ◽  
Syzygium Aromaticum ◽  
Bacterial Cells ◽  
Clove Oil ◽  
Alicyclobacillus Acidoterrestris ◽  
Agitated Culture ◽  
Clove Essential Oil ◽  
Biofilm Development

Acidotermophilic bacteria Alicyclobacillus acidoterrestris is one of the main contaminants in the fruit industry forming biofilms which are difficult to remove from the production line by conventional methods. An alternative approach aims for the use of essential oils to prevent Alicyclobacillus biofilm development. The effect of clove essential oil on A. acidoterrestris biofilms on glass and polyvinyl chloride surfaces under static and agitated culture conditions was investigated by atomic force microscopy and the plate count method. The medium-flow and the type of technical surface significantly influenced A. acidoterrestris biofilm. The PVC was colonized in a greater extent comparing to glass. Clove essential oil in 0.05% (v/v) caused 25.1–65.0% reduction of biofilms on the technical surfaces along with substantial changes in their morphology by a decrease in the biofilm: height, surface roughness, and surface area difference. The oil also induced alteration in individual bacterial cells length and visible increase of their roughness. Clove essential oil seems to release EPS from biofilm and thus induce detachment of bacteria from the surface. Due to anti-A. acidoterrestris biofilm activity, the clove oil may be used in the juice industry to hinder a development of A. acidoterrestris biofilms on production surfaces.

The Effects of Indent Residual Stresses on Mixed Mode Cyclic Crack Growth Driving Forces for Bearing Inner Rings

1987 ◽  
Vol 109 (4) ◽  
pp. 634-639 ◽  
Author(s):  
V. Bhargava ◽  
C. A. Rubin ◽  
G. T. Hahn
Keyword(s):  
Surface Layer ◽  
Residual Stresses ◽  
Crack Growth ◽  
Driving Forces ◽  
Rolling Contact ◽  
Crack Face ◽  
Press Fit ◽  
Compressive Stresses ◽  
Peak Contact Pressure ◽  
Peak Pressures

The residual stresses produced by plastic dents in a solid cylinder have been evaluated for overload, peak-contact-pressure-to-shear-strength ratios of poi/k = 3.5, and poi/k = 4. The effects of 2 sets of indent residual stresses on the cyclic crack growth driving forces generated by rolling contact at relative peak pressures of por/k = 0.5, 1.0 and 2.0, have been evaluated for 3 conditions. These are: (1) the slowly revolving ring, (2) the rapidly revolving ring with associated press fit and centrifugal stresses, and (3) the rapidly revolving ring with the superimposed circumferential compressive stresses arising from a carburized surface layer. The values of ΔKI ΔKII, and the combined mode, ΔKe, are calculated for 18 different rolling conditions, for small cracks with 8 different inclinations, 5 crack-face friction coefficients, and 21 locations in the dent region. The results show that the ΔK-values for a 2a=20μm long crack can exceed the Mode I threshold when the rim rotates slowly. Larger ΔK-values are obtained in the presence of press-fit and centrifugal stresses. However, the residual stresses of the carburized surface layer more than compensate for the press-fit and centrifugal stresses, reducing the ΔK-values below the levels obtained for the slowly rotating rim.

scholarly journals Photosynthetic hydrogen production by droplet-based microbial micro-reactors under aerobic conditions

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Zhijun Xu ◽  
Shengliang Wang ◽  
Chunyu Zhao ◽  
Shangsong Li ◽  
Xiaoman Liu ◽  
...  
Keyword(s):  
Hydrogen Production ◽  
Self Assembly ◽  
Spatial Organization ◽  
Oxygen Depletion ◽  
Bacterial Cells ◽  
Multicellular Spheroids ◽  
Two Phase ◽  
Aerobic Conditions ◽  
Micro Reactors ◽  
And Function

AbstractThe spontaneous self-assembly of multicellular ensembles into living materials with synergistic structure and function remains a considerable challenge in biotechnology and synthetic biology. Here, we exploit the aqueous two-phase separation of dextran-in-PEG emulsion micro-droplets for the capture, spatial organization and immobilization of algal cells or algal/bacterial cell communities to produce discrete multicellular spheroids capable of both aerobic (oxygen producing) and hypoxic (hydrogen producing) photosynthesis in daylight under air. We show that localized oxygen depletion results in hydrogen production from the core of the algal microscale reactor, and demonstrate that enhanced levels of hydrogen evolution can be achieved synergistically by spontaneously enclosing the photosynthetic cells within a shell of bacterial cells undergoing aerobic respiration. Our results highlight a promising droplet-based environmentally benign approach to dispersible photosynthetic microbial micro-reactors comprising segregated cellular micro-niches with dual functionality, and provide a step towards photobiological hydrogen production under aerobic conditions.

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