Significance In the natural environment majority of bacteria live within confines a structured social community called biofilm. The stability biofilms arises from extracellular matrix, which consists proteins, polysaccharides, and DNA. One these BslA, forms hydrophobic “raincoat” at surface We have uncovered mechanism that enables this protein to function, revealing structural metamorphosis form is stable in water structure prefers interface where it self-assembles with nanometer precision...

Biofilms are communities of microbial cells that encapsulated within a self-produced polymeric matrix. The matrix is critical to the success biofilms in diverse habitats; however, many details composition, structure, and function remain enigmatic. formed by Gram-positive bacterium Bacillus subtilis depend on production secreted film-forming protein BslA. Here, we show gradient electron acceptor availability through depth biofilm gives rise two distinct functional roles for BslA these can be...

In small volumes, the kinetics of filamentous protein self-assembly is expected to show significant variability, arising from intrinsic molecular noise. This not accounted for in existing deterministic models. We introduce a simple stochastic model including nucleation and autocatalytic growth via elongation fragmentation, which allows us predict effects noise on self-assembly. derive an analytic expression lag-time distribution, agrees well with experimental results fibrillation bovine...

Bacterial biofilms are communities of microbial cells encased within a self-produced polymeric matrix. In the Bacillus subtilis biofilm matrix, extracellular fibres TasA essential. Here, recombinant expression system allows interrogation TasA, revealing that monomeric and fibre forms have identical secondary structure, suggesting fibrous is linear assembly globular units. Recombinant form spontaneously, share biological activity extracted from B. subtilis, whereas variant restricted to...

Many proteins that self-assemble into amyloid and amyloid-like fibers can adopt diverse polymorphic forms. These forms have been observed both in vitro vivo arise through variations the steric-zipper interactions between β-sheets, arrangements protofilaments, differences number of protofilaments make up a given fiber class. Different polymorphs arising from same precursor molecule not only exhibit different levels toxicity, but importantly contribute to disease conditions. However, factors...

ABSTRACT The extracellular matrix of biofilms provides crucial structural support to the community and protection from environmental perturbations. TasA, a key Bacillus subtilis biofilm protein, forms both amyloid non‐amyloid fibrils. Non‐amyloid TasA fibrils are formed via strand‐exchange mechanism, whereas amyloid‐like form involves non‐specific self‐assembly. We performed mutagenesis N‐terminus assess role in development. find that N‐terminal tail is essential for formation structured...

Engineering whole organs from porcine decellularized extracellular matrix and human cells may lead to a plentiful source of implantable organs. Decontaminating the scaffolds is an essential step prior introducing cells. However, decontamination kidneys major challenge because agent or irradiation needs diffuse deep into structure eliminate all microbial contamination while minimizing damage composition matrix. In this study, we compared four treatments that could be applicable kidneys: 70%...

Bacteria which grow not on the featureless agar plates of microbiology lab but in real world must navigate topologies are nontrivially complex, such as mazes or fractals. We show that chemosensitive motile E. coli can efficiently explore nontrivial times much shorter than a no-memory (Markovian) walk would predict, and collectively escape from fractal topology. The strategies used by bacteria include individual power-law probability distribution function exploration, launching chemotactic...

BslA is an amphiphilic protein that forms a highly hydrophobic coat around Bacillus subtilis biofilms, shielding the bacterial community from external aqueous solution. It has unique structure featuring distinct partition between hydrophilic and surfaces. This surface property reminiscent of synthesized Janus colloids. By investigating behavior variants at water-cyclohexane interfaces through set multiscale simulations informed by experimental data, we show indeed represents biological...

Abstract BslA is a protein secreted by Bacillus subtilis which forms hydrophobic film that coats the biofilm surface and renders it water-repellent. We have characterised three orthologues of from amyloliquefaciens , licheniformis pumilus as well paralogue B . called YweA. find orthologous proteins can substitute for in confer degree protection, whereas YweA cannot. The to functionally native correlates with their vitro biophysical properties. Our results demonstrate use naturally-evolved...

Mass spectrometry shows insulin oligomers [I] n where ranges from 1-12, and ion mobility analysis reveals ∼60 structurally distinct species across this oligomer distribution. Experimental data trains MD simulations to characterize a persistent prefibrillar protein that is dimer enriched in β sheets.

Microbial growth often occurs within multicellular communities called biofilms, where cells are enveloped by a protective extracellular matrix. Bacillus subtilis serves as model organism for biofilm research and produces two crucial secreted proteins, BslA TasA, vital matrix formation. exhibits surface-active properties, spontaneously self-assembling at hydrophobic/hydrophilic interfaces to form an elastic protein film, which renders B. surfaces water-repellent. TasA is traditionally...

Intrinsically interfacially active proteins have garnered considerable interest recently owing to their potential use in a range of materials applications. Notably, the fungal hydrophobins are known form robust and well-organized surface layers with high mechanical strength. Recently, it was shown that bacterial biofilm protein BslA also forms highly elastic at interfaces. Here we describe several self-assembled structures formed by BslA, both interfaces bulk solution, over length scales...

Claudin 6 (Cldn6) is a tetraspanin protein expressed by barrier epithelial cells. In order to assess the effects of persistent tight junctions involving Cldn6 during lung development, doxycycline (dox)-inducible conditional transgenic mouse was generated that up-regulates in distal lung. Pups had unlimited access dox from conception until sacrifice date at embryonic day (E) 18.5. Quantitative PCR, immunoblotting, and immunohistochemistry revealed significantly elevated expression mice...

Abstract The exhaust detritiation system (EDS) of the Joint European Torus (JET) active gas handling removes tritium from gases and contaminated air prior to discharge stack. was replaced JET’s experimental campaign due corrosion damage. In this paper, following topics are presented: function description, failure previous EDS, enhancements for replacement EDS including testing acid passivation column, commissioning experience, operating experience performance. Acids hydrofluoric were...

We use a microfluidic ecology which generates non-uniform phage concentration gradients and micro-ecological niches to reveal the importance of time, spatial population structure collective dynamics in de

Significance We have discovered an emergent mechanism by which Escherichia coli can escape high-stress regions, such as near-lethal concentrations of antibiotics, forming long motile helical filaments that are poized at the critical shear buckling point: 2 <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>π</mml:mi> </mml:math> twist rotations independent length filament. All filaments, length, same twist, indicating this is a highly evolved response. The...

The soil bacterium Bacillus subtilis is a model organism to investigate the formation of biofilms, predominant form microbial life. secreted protein BslA self-assembles at surface biofilm give B. its characteristic hydrophobicity. To understand mechanism self-assembly interfaces, here we built molecular based on previous crystal structure and paralogue YweA that determined. Our analysis revealed two conserved protein–protein interaction interfaces supporting into an infinite 2-dimensional...

Abstract A hallmark of microbial biofilms is the self-production an extracellular molecular matrix that encases resident cells. The provides protection from environment, while spatial heterogeneity gene expression influences structural morphology and colony spreading dynamics. Bacillus subtilis a model bacterial system used to uncover regulatory pathways key building blocks required for biofilm growth development. In this work, we report on emergence highly active population bacteria during...