scholarly journals Surfactin production is not essential for pellicle and root-associated biofilm development of Bacillus subtilis

2019 ◽  
Author(s):  
Maude Thérien ◽  
Heiko T. Kiesewalter ◽  
Emile Auria ◽  
Vincent Charron-Lamoureux ◽  
Mario Wibowo ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Biofilm Formation ◽  
Plant Root ◽  
Model Systems ◽  
Colony Development ◽  
Laboratory Model ◽  
Pellicle Formation ◽  
Surfactin Production ◽  
Biofilm Development ◽  
The Impact

AbstractSecondary metabolites have an important impact on the biocontrol potential of soil-derived microbes. In addition, various microbe-produced chemicals have been suggested to impact the development and phenotypic differentiation of bacteria, including biofilms. The non-ribosomal synthesized lipopeptide of Bacillus subtilis, surfactin, has been described to impact the plant promoting capacity of the bacterium. Here, we investigated the impact of surfactin production on biofilm formation of B. subtilis using the laboratory model systems; pellicle formation at the air-medium interface and architecturally complex colony development, in addition to plant root-associated biofilms. We found that the production of surfactin by B. subtilis is not essential for pellicle biofilm formation neither in the well-studied strain, NCIB 3610, nor in the newly isolated environmental strains, but lack of surfactin reduces colony expansion. Further, plant root colonization was comparable both in the presence or absence of surfactin synthesis. Our results suggest that surfactin-related biocontrol and plant promotion in B. subtilis strains are independent of biofilm formation.

scholarly journals Cyclic di-AMP Acts as an Extracellular Signal That ImpactsBacillus subtilisBiofilm Formation and Plant Attachment

mBio ◽  
2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Loni Townsley ◽  
Sarah M. Yannarell ◽  
Tuanh Ngoc Huynh ◽  
Joshua J. Woodward ◽  
Elizabeth A. Shank
Keyword(s):  
Gene Expression ◽  
Bacillus Subtilis ◽  
Intracellular Signaling ◽  
Biofilm Formation ◽  
Plant Root ◽  
Second Messenger ◽  
Pathogen Resistance ◽  
Plant Roots ◽  
Extracellular Signal ◽  
The Impact

ABSTRACTThere is a growing appreciation for the impact that bacteria have on higher organisms. Plant roots often harbor beneficial microbes, such as the Gram-positive rhizobacteriumBacillus subtilis, that influence their growth and susceptibility to disease. The ability to form surface-attached microbial communities called biofilms is crucial for the ability ofB. subtilisto adhere to and protect plant roots. In this study, strains harboring deletions of theB. subtilisgenes known to synthesize and degrade the second messenger cyclic di-adenylate monophosphate (c-di-AMP) were examined for their involvement in biofilm formation and plant attachment. We found that intracellular production of c-di-AMP impacts colony biofilm architecture, biofilm gene expression, and plant attachment inB. subtilis. We also show thatB. subtilissecretes c-di-AMP and that putative c-di-AMP transporters impact biofilm formation and plant root colonization. Taken together, our data describe a new role for c-di-AMP as a chemical signal that affects important cellular processes in the environmentally and agriculturally important soil bacteriumB. subtilis. These results suggest that the “intracellular” signaling molecule c-di-AMP may also play a previously unappreciated role in interbacterial cell-cell communication within plant microbiomes.IMPORTANCEPlants harbor bacterial communities on their roots that can significantly impact their growth and pathogen resistance. In most cases, however, the signals that mediate host-microbe and microbe-microbe interactions within these communities are unknown. A detailed understanding of these interaction mechanisms could facilitate the manipulation of these communities for agricultural or environmental purposes.Bacillus subtilisis a plant-growth-promoting bacterium that adheres to roots by forming biofilms. We therefore began by exploring signals that might impact its biofilm formation. We found thatB. subtilissecretes c-di-AMP and that the ability to produce, degrade, or transport cyclic di-adenylate monophosphate (c-di-AMP; a common bacterial second messenger) affectsB. subtilisbiofilm gene expression and plant attachment. To our knowledge, this is the first demonstration of c-di-AMP impacting a mutualist host-microbe association and suggests that c-di-AMP may function as a previously unappreciated extracellular signal able to mediate interactions within plant microbiomes.

scholarly journals Deletion of Rap‐Phr systems in Bacillus subtilis influences in vitro biofilm formation and plant root colonization

2021 ◽  
Vol 10 (3) ◽  
Author(s):  
Mathilde Nordgaard ◽  
Rasmus Møller Rosenbek Mortensen ◽  
Nikolaj Kaae Kirk ◽  
Ramses Gallegos‐Monterrosa ◽  
Ákos T. Kovács
Keyword(s):  
Bacillus Subtilis ◽  
Biofilm Formation ◽  
Root Colonization ◽  
Plant Root

scholarly journals Characterization of Temporal Protein Production in Pseudomonas aeruginosa Biofilms

2005 ◽  
Vol 187 (23) ◽  
pp. 8114-8126 ◽  
Author(s):  
Christopher J. Southey-Pillig ◽  
David G. Davies ◽  
Karin Sauer
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibiotic Resistance ◽  
Biofilm Formation ◽  
Protein Production ◽  
Developmental Stages ◽  
Developmental Process ◽  
Developmental Cycle ◽  
Specific Proteins ◽  
Biofilm Development ◽  
The Impact

ABSTRACT Phenotypic and genetic evidence supporting the notion of biofilm formation as a developmental process is growing. In the present work, we provide additional support for this hypothesis by identifying the onset of accumulation of biofilm-stage specific proteins during Pseudomonas aeruginosa biofilm maturation and by tracking the abundance of these proteins in planktonic and three biofilm developmental stages. The onset of protein production was found to correlate with the progression of biofilms in developmental stages. Protein identification revealed that proteins with similar function grouped within similar protein abundance patterns. Metabolic and housekeeping proteins were found to group within a pattern separate from virulence, antibiotic resistance, and quorum-sensing-related proteins. The latter were produced in a progressive manner, indicating that attendant features that are characteristic of biofilms such as antibiotic resistance and virulence may be part of the biofilm developmental process. Mutations in genes for selected proteins from several protein production patterns were made, and the impact of these mutations on biofilm development was evaluated. The proteins cytochrome c oxidase, a probable chemotaxis transducer, a two-component response regulator, and MexH were produced only in mature and late-stage biofilms. Mutations in the genes encoding these proteins did not confer defects in growth, initial attachment, early biofilm formation, or twitching motility but were observed to arrest biofilm development at the stage of cell cluster formation we call the maturation-1 stage. The results indicated that expression of theses genes was required for the progression of biofilms into three-dimensional structures on abiotic surfaces and the completion of the biofilm developmental cycle. Reverse transcription-PCR analysis confirmed the detectable change in expression of the respective genes ccoO, PA4101, and PA4208. We propose a possible mechanism for the role of these biofilm-specific proteins in biofilm formation.

scholarly journals The Relative Importance of Shear Forces and Surface Hydrophobicity on Biofilm Formation by Coccoid Cyanobacteria

Polymers ◽  
2020 ◽  
Vol 12 (3) ◽  
pp. 653 ◽  
Author(s):  
Sara I. Faria ◽  
Rita Teixeira-Santos ◽  
Maria J. Romeu ◽  
João Morais ◽  
Vitor Vasconcelos ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Hydrophobic Surface ◽  
Surface Hydrophobicity ◽  
Polymeric Coating ◽  
Relative Importance ◽  
Hydrodynamic Conditions ◽  
Shear Forces ◽  
Lower Shear ◽  
Biofilm Development ◽  
The Impact

Understanding the conditions affecting cyanobacterial biofilm development is crucial to develop new antibiofouling strategies and decrease the economic and environmental impact of biofilms in marine settings. In this study, we investigated the relative importance of shear forces and surface hydrophobicity on biofilm development by two coccoid cyanobacteria with different biofilm formation capacities. The strong biofilm-forming Synechocystis salina was used along with the weaker biofilm-forming Cyanobium sp. Biofilms were developed in defined hydrodynamic conditions using glass (a model hydrophilic surface) and a polymeric epoxy coating (a hydrophobic surface) as substrates. Biofilms developed in both surfaces at lower shear conditions contained a higher number of cells and presented higher values for wet weight, thickness, and chlorophyll a content. The impact of hydrodynamics on biofilm development was generally stronger than the impact of surface hydrophobicity, but a combined effect of these two parameters strongly affected biofilm formation for the weaker biofilm-producing organism. The antibiofilm performance of the polymeric coating was confirmed at the hydrodynamic conditions prevailing in ports. Shear forces were shown to have a profound impact on biofilm development in marine settings regardless of the fouling capacity of the existing flora and the hydrophobicity of the surface.

scholarly journals A Sustained-Release Membrane of Thiazolidinedione-8: Effect on Formation of a Candida/Bacteria Mixed Biofilm on Hydroxyapatite in a Continuous Flow Model

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Mark Feldman ◽  
Julia Shenderovich ◽  
Eran Lavy ◽  
Michael Friedman ◽  
Doron Steinberg
Keyword(s):  
Sustained Release ◽  
Biofilm Formation ◽  
Active Agent ◽  
Extracellular Polysaccharides ◽  
Flow Conditions ◽  
Biofilm Thickness ◽  
Release Drug ◽  
Flow Through ◽  
Biofilm Development ◽  
The Impact

Thiazolidinediones (TZDs) have been found to act as effective quorum sensing quenchers, capable of preventing biofilm formation. Our previous studies demonstrated a profound antibiofilm effect of the TZD derivative thiazolidinedione-8 (S-8), either in solution or incorporated into a sustained-release membrane (SRM-S-8) under batch conditions. In the present study, we used a constant depth film fermenter model in order to investigate the impact of SRM-S-8 on mixedC. albicans-S. mutansbiofilm development, under flow conditions. We found that essential parameters of cospecies biofilm maintenance and maturation, such as metabolic activity, biofilm thickness, roughness, extracellular polysaccharides production, and morphology of both pathogens, were altered by SRM-S-8 in the flow system. We propose that prolonged and sustained release of S-8 in a flow-through system allows better penetration of the active agent to deeper layers of the mixed biofilm, thereby increasing its activity against both pathogens. In conclusion, the use of a locally applied sustained-release drug delivery system of S-8 can affect the dental polymicrobial biofilm, resulting in clinical improvements and a better patient compliance.

scholarly journals Decreasing Serine Levels During Growth Transition Triggers Biofilm Formation inBacillus subtilis

2019 ◽  
Author(s):  
Jennifer Greenwich ◽  
Alicyn Reverdy ◽  
Kevin Gozzi ◽  
Grace Di Cecco ◽  
Tommy Tashjian ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Stationary Phase ◽  
Biofilm Formation ◽  
Exponential Phase ◽  
Growth Stages ◽  
Translation Rate ◽  
Biofilm Development ◽  
Ribosome Pausing ◽  
Trna Isoacceptors ◽  
Serine Codons

ABSTRACTBiofilm development inBacillus subtilisis regulated at multiple levels. While a number of known signals that trigger biofilm formation do so through the activation of one or more sensory histidine kinases, it was recently discovered that biofilm activation is also coordinated by sensing intracellular metabolic signals, including serine starvation. Serine starvation causes ribosomes to pause on specific serine codons, leading to a decrease in the translation rate ofsinR, which encodes a master repressor for biofilm matrix genes, and ultimately biofilm induction. How serine levels change in different growth stages, howB. subtilisregulates intracellular serine levels in response to metabolic status, and how serine starvation triggers ribosomes to pause on selective serine codons remain unknown. Here we show that serine levels decrease as cells enter stationary phase and that unlike most other amino acid biosynthesis genes, expression of serine biosynthesis genes decreases upon the transition into stationary phase. Deletion of the gene for a serine deaminase responsible for converting serine to pyruvate led to a delay in biofilm formation, further supporting the idea that serine levels are a critical intracellular signal for biofilm activation. Finally, we show that levels of all five serine tRNA isoacceptors are decreased in stationary phase compared to exponential phase. Interestingly, the three isoacceptors recognizing UCN serine codons are reduced to a much greater extent than the two that recognize AGC and AGU serine codons. Our findings provide evidence for a link between serine homeostasis and biofilm development inB. subtilis.IMPORTANCEInBacillus subtilis, biofilm formation is triggered in response to various environmental and cellular signals. It was previously proposed that serine limitation acts as a proxy for nutrient status and triggers biofilm formation at the onset of biofilm entry through a novel signaling mechanism caused by global ribosome pausing on selective serine codons. In this study, we revealed that serine levels decrease at the biofilm entry due to catabolite control and a shunt mechanism. We also show that levels of five serine tRNA isoacceptors are differentially decreased in stationary phase compared to exponential phase; three isoacceptors recognizing UCN serine codons are reduced much greater than the two recognizing AGC and AGU codons. This indicates a possible mechanism for selective ribosome pausing.

scholarly journals Phages associated with horses provide new insights into the dominance of lateral gene transfer in virulent bacteriophages evolution in natural systems

2019 ◽  
Author(s):  
V.V. Babenko ◽  
A.K. Golomidova ◽  
P.A. Ivanov ◽  
M.A. Letarova ◽  
E.E. Kulikov ◽  
...  
Keyword(s):  
Time Scale ◽  
Natural Habitat ◽  
Local Population ◽  
Point Mutations ◽  
Major Effect ◽  
Model Systems ◽  
Laboratory Model ◽  
Short Time Scale ◽  
Short Time ◽  
The Impact

AbstractTailed bacteriophages (Caudovirales order) are omnipresent on our planet. Their impressive ecological and evolutionary success largely relies on the bacteriophage potential to adapt to great variety of the environmental conditions found in the Biosphere. It is believed that the adaptation of bacteriophages, including short time scale adaptation, is achieved almost exclusively via the (micro)evolution processes. In order to analyze the major mechanisms driving adaptation of phage genomes in a natural habitat we used comparative genomics of G7C-like coliphage isolates obtained during 7 years period from the feces of the horses belonging to a local population. The data suggest that even at this relatively short time scale the impact of various recombination events overwhelms the impact of the accumulation of point mutations. The access to the large pool of the genes of a complex microbial and viral community of the animal gut had major effect on the evolutionary trajectories of these phages. Thus the “real world” bacteriophage evolution mechanisms may differ significantly from those observed in the simplified laboratory model systems.

The versatile effect of L- and D-Cateslytin on bacteria and yeast biofilms according to configuration, medium and dose

2020 ◽  
Author(s):  
Lydie Ploux ◽  
Min Jin ◽  
Sophie Hellé ◽  
Cosette Betscha ◽  
Jean-Marc Strub ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Antimicrobial Agents ◽  
Antimicrobial Properties ◽  
P Value ◽  
Microbial Cells ◽  
Response System ◽  
Stress Response System ◽  
Biofilm Development ◽  
The Impact

<p>L- and D-Cateslytin (CTL) are antimicrobial peptides (AMP) derived from chromogranin A, a protein of the stress response system. Their antimicrobial properties have been thoroughly characterized and already exploited in biomaterials. However, effects on biofilms of yeast and bacteria have never been specifically addressed. We have investigated the impact of both L and D configurations of CTL on the growth of biofilms formed by Candida albicans, Escherichia coli or Staphylococcus aureus microorganisms.</p> <p>The study was conducted in different media and two strategies of treatment were tested, consisting of administrating the peptide either just at the beginning of biofilm development i.e. on just adhering pioneer microbial cells or on a biofilm already allowed to develop for 24h. We also considered whether the peptide was modified in contact with the medium or/and microbial metabolites. Planktonic and sessile populations of microbial cells were analyzed by spectrophotometry, crystal violet staining, MTT and confocal microscopy with staining by Syto9Ò and propidium iodide. Identification of the peptides and their derived fragments was investigated by HPLC and Mass-Spectroscopy.</p> <p>In general, CTL-D exhibited higher antibiofilm performances than CTL-L. In addition, concentrations necessary to inhibit biofilm formation were found to vary from ten to eighty times the MICs determined in planktonic cultures. Nevertheless, the results also demonstrate that sessile microorganisms and biofilms are sensitive to CTL (L and D conformations) differently that planktonic populations. Significant (p-value < 0.01) effects were observed on both sessile and planktonic populations and with both strategies of treatments, but they highly varied with medium, species and CTL configuration. Typically, better antibiofilm effect than common antibiotics was reached in some specific conditions, while enhancement of aggregation or biofilm formation occurred in another medium and for other doses. Nevertheless,</p> <p>Finally, this confirms the quality of CTL peptides as new antimicrobial agents and reveals their anti-biofilm properties. This also specifies the conditions of use necessary to benefit of the highest performances.</p>

scholarly journals RemA (YlzA) and RemB (YaaB) Regulate Extracellular Matrix Operon Expression and Biofilm Formation in Bacillus subtilis

2009 ◽  
Vol 191 (12) ◽  
pp. 3981-3991 ◽  
Author(s):  
Jared T. Winkelman ◽  
Kris M. Blair ◽  
Daniel B. Kearns
Keyword(s):  
Extracellular Matrix ◽  
Bacillus Subtilis ◽  
Biofilm Formation ◽  
Extracellular Polysaccharide ◽  
Pellicle Formation ◽  
Multicellular Aggregates ◽  
The Matrix ◽  
Matrix Components ◽  
Operon Expression ◽  
Motility Inhibition

ABSTRACT Biofilms are multicellular aggregates stabilized by an extracellular matrix. In Bacillus subtilis, the biofilm matrix is composed of an extracellular polysaccharide and the secreted protein TasA. Expression of both of the matrix components is repressed by the DNA-binding master regulator, SinR. Here we identify two small protein regulators of the extracellular matrix: RemA (formerly YlzA) and RemB (formerly YaaB). Mutation of RemA or RemB impairs pellicle formation, complex colony architecture, and motility inhibition in a sinR mutant background. Both proteins are required for the activation of the matrix biosynthesis operons and appear to act in parallel to SinR and two other known biofilm regulators, AbrB and DegU.

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