Social evolution of shared biofilm matrix components

Biofilm formation is an important and ubiquitous mode of growth among bacteria. Central to the evolutionary advantage of biofilm formation is cell-cell and cell-surface adhesion achieved by a variety of factors, some of which are diffusible compounds that may operate as classical public goods - factors that are costly to produce but may benefit other cells. An outstanding question is how diffusible matrix production, in general, can be stable over evolutionary timescales. In this work, using Vibrio cholerae as a model, we show that shared diffusible biofilm matrix proteins are indeed susceptible to cheater exploitation, and that the evolutionary stability of producing these matrix components fundamentally depends on biofilm spatial structure, intrinsic sharing mechanisms of these components, and flow conditions in the environment. We further show that exploitation of diffusible adhesion proteins is localized within a well-defined spatial range around cell clusters that produce them. Based on this exploitation range and the spatial distribution of cell clusters, we construct a model of costly diffusible matrix production and relate these length scales to the relatedness coefficient in social evolution theory. Our results show that production of diffusible biofilm matrix components is evolutionarily stable under conditions consistent with natural biofilm habitats and host environments. We expect the mechanisms revealed in this study to be relevant to other secreted factors that operate as cooperative public goods in bacterial communities, and the concept of exploitation range and the associated analysis tools to be generally applicable.

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Division of labor during biofilm matrix production

10.1101/237230 ◽

2017 ◽

Cited By ~ 1

Author(s):

Anna Dragoš ◽

Heiko Kiesewalter ◽

Marivic Martin ◽

Chih-Yu Hsu ◽

Raimo Hartmann ◽

...

Keyword(s):

Public Goods ◽

Division Of Labor ◽

Strain Ratio ◽

Relative Fitness ◽

Fruiting Body Formation ◽

Matrix Production ◽

Matrix Components ◽

Genetic Division ◽

Biofilm Matrix

SummaryOrganisms as simple as bacteria can engage in complex collective actions, such as group motility and fruiting body formation. Some of these actions involve a division of labor, where phenotypically specialized clonal subpopulations, or genetically distinct lineages cooperate with each other by performing complementary tasks. Here, we combine experimental and computational approaches to investigate potential benefits arising from division of labor during biofilm matrix production. We show that both phenotypic and genetic strategies for a division of labor can promote collective biofilm formation in the soil bacteriumBacillus subtilis. In this species, biofilm matrix consists of two major components; EPS and TasA. We observed that clonal groups ofB. subtilisphenotypically segregate into three subpopulations composed of matrix non-producers, EPS-producers, and generalists, which produce both EPS and TasA. This incomplete phenotypic specialization was outperformed by a genetic division of labor, where two mutants, engineered as specialists, complemented each other by exchanging EPS and TasA. The relative fitness of the two mutants displayed a negative frequency dependence bothin vitroand on plant roots, with strain frequency reaching a stable equilibrium at 30% TasA-producers, corresponding exactly to the population composition where group productivity is maximized. Using individual-based modelling, we show that asymmetries in strain ratio can arise due to differences in the relative benefits that matrix compounds generate for the collective; and that genetic division of labor can be favored when it breaks metabolic constraints associated with the simultaneous production of two matrix components.Highlights- matrix components EPS and TasA are costly public goods inB. subtilisbiofilms- genetic division of labor using Δepsand ΔtasAfosters maximal biofilm productivity- Δepsand ΔtasAcooperation is evolutionary stable in laboratory and ecological systems- costly metabolic coupling of public goods favors genetic division of labor

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Quorum sensing in Bacillus subtilis slows down biofilm formation by enabling sporulation bet hedging

10.1101/768671 ◽

2019 ◽

Author(s):

Mihael Spacapan ◽

Tjaša Danevčič ◽

Polonca Štefanic ◽

Ines Mandic-Mulec

Keyword(s):

Bacillus Subtilis ◽

Quorum Sensing ◽

Biofilm Formation ◽

Bet Hedging ◽

Wild Type ◽

Master Regulator ◽

Matrix Components ◽

Sporulation Initiation ◽

Biofilm Development ◽

Biofilm Matrix

1.2ABSTRACTThe ComQXPA quorum sensing (QS) system of Bacillus subtilis, a Gram-positive, industrially relevant, endospore forming bacterium, promotes surfactin production. This lipopeptide increases transcription of several genes involved in biofilm matrix synthesis via the Spo0A-P master regulator. We hypothesized that the inactivation of the QS system will therefore result in decreased rates of floating biofilm formation. We find that this is not the case and that the QS deficient mutant forms pellicles with a faster rate and produces more biofilm matrix components than the wild type. As Spo0A-P is the master regulator of sporulation initiation we hypothesized that the ComQXPA dependent signaling promotes sporulation and consequently slows the growth rate of the wild type strain. Indeed, our results confirm that cells with the inactive QS initiate endospore formation in biofilms later and more synchronously than the wild type, as evidenced by spore frequencies and the PspoIIQ promoter activity. We argue, that the QS system acts as a switch that promotes stochastic sporulation initiation and consequently bet hedging behavior. By committing a subpopulation of cells to sporulation early during growth, wild type population grows slower and produces thinner biofilms but also assures better survival under stressful conditions.1.1IMPORTANCEBacillus subtilis is widely employed model organism to study biofilm formation and sporulation in Gram-positive bacteria. The ComQXPA quorum sensing (QS) system indirectly increases the transcription of genes involved in biofilm matrix formation, which predicts a positive role of this QS in biofilm development Here we show that QS mutants actually form more matrix components per pellicle than the wild type and that their pellicles are thicker and form with a faster rate. We explain this, by showing that cells with an inactive QS exhibit a delay in sporulation entry, which is also more synchronous relative to the wild type. We argue, that the ComQXPA QS system acts as a switch that contributes to the stochastic sporulation initiation and though this path promotes bet hedging behavior. This finding is important in terms of “quorum quenching” strategies aiming to down modulate biofilm development through inhibition of QS signaling and underscores the richness of QS regulated phenotypic outcomes among bacterial species.

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Spatio-temporal formation of biofilms and extracellular matrix analysis in Azospirillum brasilense

FEMS Microbiology Letters ◽

10.1093/femsle/fnaa037 ◽

2020 ◽

Vol 367 (4) ◽

Author(s):

Víctor I Viruega-Góngora ◽

Iris S Acatitla-Jácome ◽

Sandra R Reyes-Carmona ◽

Beatriz E Baca ◽

Alberto Ramírez-Mata

Keyword(s):

Extracellular Matrix ◽

Biofilm Formation ◽

Azospirillum Brasilense ◽

Laser Scanning Microscopy ◽

Extracellular Dna ◽

Polar Flagellum ◽

Matrix Components ◽

Spatio Temporal ◽

Biofilm Development ◽

Biofilm Matrix

ABSTRACT Elucidation of biofilm structure formation in the plant growth-promoting rhizobacterium Azospirillum brasilense is necessary to gain a better understanding of the growth of cells within the extracellular matrix and its role in the colonization of plants of agronomic importance. We used immunofluorescence microscopy and confocal laser scanning microscopy to study spatio-temporal biofilm formation on an abiotic surface. Observations facilitated by fluorescence microscopy revealed the presence of polar flagellin, exopolysaccharides, outer major membrane protein (OmaA) and extracellular DNA in the Azospirillum biofilm matrix. In static culture conditions, the polar flagellum disaggregated after 3 days of biofilm growth, but exopolysaccharides were increasing. These findings suggest that the first step in biofilm formation may be attachment, in which the bacterium first makes contact with a surface through its polar flagellum. After attaching to the surface, the long flagella and OmaA intertwine the cells to form a network. These bacterial aggregates initiate biofilm development. The underlying mechanisms dictating how the biofilm matrix components of A. brasilense direct the overall morphology of the biofilm are not well known. The methods developed here might be useful in further studies that analyze the differential spatial regulation of genes encoding matrix components that drive biofilm construction.

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Anti-Biofilm Molecules Targeting Functional Amyloids

Antibiotics ◽

10.3390/antibiotics10070795 ◽

2021 ◽

Vol 10 (7) ◽

pp. 795

Author(s):

Leticia Matilla-Cuenca ◽

Alejandro Toledo-Arana ◽

Jaione Valle

Keyword(s):

Biofilm Formation ◽

Therapeutic Strategy ◽

Research Area ◽

Therapeutic Strategies ◽

Structural Components ◽

Significant Issue ◽

Wide Range ◽

Effective Therapeutic Strategy ◽

Functional Amyloids ◽

Biofilm Matrix

The choice of an effective therapeutic strategy in the treatment of biofilm-related infections is a significant issue. Amyloids, which have been historically related to human diseases, are now considered to be prevailing structural components of the biofilm matrix in a wide range of bacteria. This assumption creates the potential for an exciting research area, in which functional amyloids are considered to be attractive targets for drug development to dissemble biofilm structures. The present review describes the best-characterized bacterial functional amyloids and focuses on anti-biofilm agents that target intrinsic and facultative amyloids. This study provides a better understanding of the different modes of actions of the anti-amyloid molecules to inhibit biofilm formation. This information can be further exploited to improve the therapeutic strategies to combat biofilm-related infections.

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Archaeal biofilms: widespread and complex

Biochemical Society Transactions ◽

10.1042/bst20120304 ◽

2013 ◽

Vol 41 (1) ◽

pp. 393-398 ◽

Cited By ~ 52

Author(s):

Sabrina Fröls

Keyword(s):

Biofilm Formation ◽

Extracellular Polymeric Substances ◽

Bacterial Species ◽

Surface Adhesion ◽

Form Complex ◽

Abiotic Surfaces ◽

Archaeal Species ◽

Physical And Chemical ◽

Insight Into ◽

Mixed Communities

Biofilms or multicellular structures become accepted as the dominant microbial lifestyle in Nature, but in the past they were only studied extensively in bacteria. Investigations on archaeal monospecies cultures have shown that many archaeal species are able to adhere on biotic and abiotic surfaces and form complex biofilm structures. Biofilm-forming archaea were identified in a broad range of extreme and moderate environments. Natural biofilms observed are mostly mixed communities composed of archaeal and bacterial species of various abundances. The physiological functions of the archaea identified in such mixed communities suggest a significant impact on the biochemical cycles maintaining the flow and recycling of the nutrients on earth. Therefore it is of high interest to investigate the characteristics and mechanisms underlying the archaeal biofilm formation. In the present review, I summarize and discuss the present investigations of biofilm-forming archaeal species, i.e. their diverse biofilm architectures in monospecies or mixed communities, the identified EPSs (extracellular polymeric substances), archaeal structures mediating surface adhesion or cell–cell connections, and the response to physical and chemical stressors implying that archaeal biofilm formation is an adaptive reaction to changing environmental conditions. A first insight into the molecular differentiation of cells within archaeal biofilms is given.

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Identification and Characterization of OscR, a Transcriptional Regulator Involved in Osmolarity Adaptation in Vibrio cholerae

Journal of Bacteriology ◽

10.1128/jb.01540-08 ◽

2009 ◽

Vol 191 (13) ◽

pp. 4082-4096 ◽

Cited By ~ 44

Author(s):

Nicholas J. Shikuma ◽

Fitnat H. Yildiz

Keyword(s):

Vibrio Cholerae ◽

Biofilm Formation ◽

Transcriptional Regulator ◽

Dependent Manner ◽

Genome Wide ◽

Low Salt ◽

Adaptation Response ◽

Matrix Production ◽

Identification And Characterization

ABSTRACT Vibrio cholerae is a facultative human pathogen. In its aquatic habitat and as it passes through the digestive tract, V. cholerae must cope with fluctuations in salinity. We analyzed the genome-wide transcriptional profile of V. cholerae grown at different NaCl concentrations and determined that the expression of compatible solute biosynthesis and transporter genes, virulence genes, and genes involved in adhesion and biofilm formation is differentially regulated. We determined that salinity modulates biofilm formation, and this response was mediated through the transcriptional regulators VpsR and VpsT. Additionally, a transcriptional regulator controlling an osmolarity adaptation response was identified. This regulator, OscR (osmolarity controlled regulator), was found to modulate the transcription of genes involved in biofilm matrix production and motility in a salinity-dependent manner. oscR mutants were less motile and exhibited enhanced biofilm formation only under low-salt conditions.

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PBP4 and PBP5 are involved in regulating exopolysaccharide synthesis during Escherichia coli biofilm formation

Microbiology ◽

10.1099/mic.0.001031 ◽

2021 ◽

Vol 167 (3) ◽

Author(s):

Sathi Mallick ◽

Shanti Kiran ◽

Tapas Kumar Maiti ◽

Anindya S. Ghosh

Keyword(s):

Escherichia Coli ◽

Biofilm Formation ◽

Type Species ◽

Pentose Phosphate ◽

Bacterial Cells ◽

Surface Adhesion ◽

Content Type ◽

Penicillin Binding Proteins ◽

E Coli ◽

Link Type

Escherichia coli low-molecular-mass (LMM) Penicillin-binding proteins (PBPs) help in hydrolysing the peptidoglycan fragments from their cell wall and recycling them back into the growing peptidoglycan matrix, in addition to their reported involvement in biofilm formation. Biofilms are external slime layers of extra-polymeric substances that sessile bacterial cells secrete to form a habitable niche for themselves. Here, we hypothesize the involvement of Escherichia coli LMM PBPs in regulating the nature of exopolysaccharides (EPS) prevailing in its extra-polymeric substances during biofilm formation. Therefore, this study includes the assessment of physiological characteristics of E. coli CS109 LMM PBP deletion mutants to address biofilm formation abilities, viability and surface adhesion. Finally, EPS from parent CS109 and its ΔPBP4 and ΔPBP5 mutants were purified and analysed for sugars present. Deletions of LMM PBP reduced biofilm formation, bacterial adhesion and their viability in biofilms. Deletions also diminished EPS production by ΔPBP4 and ΔPBP5 mutants, purification of which suggested an increased overall negative charge compared with their parent. Also, EPS analyses from both mutants revealed the appearance of an unusual sugar, xylose, that was absent in CS109. Accordingly, the reason for reduced biofilm formation in LMM PBP mutants may be speculated as the subsequent production of xylitol and a hindrance in the standard flow of the pentose phosphate pathway.

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Staphylococcus aureuscoagulases are exploitable yet stable public goods in clinically relevant conditions

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1804850115 ◽

2018 ◽

Vol 115 (50) ◽

pp. E11771-E11779 ◽

Cited By ~ 2

Author(s):

Urvish Trivedi ◽

Jonas S. Madsen ◽

Jake Everett ◽

Cody Fell ◽

Jakob Russel ◽

...

Keyword(s):

Public Goods ◽

Social Evolution ◽

Defense Mechanism ◽

Critical Role ◽

Local Population ◽

Coagulation Cascade ◽

The Public ◽

Innate Defense ◽

The Commons

Coagulation is an innate defense mechanism intended to limit blood loss and trap invading pathogens during infection. However,Staphylococcus aureushas the ability to hijack the coagulation cascade and generate clots via secretion of coagulases. Although manyS. aureushave this characteristic, some do not. The population dynamics regarding this defining trait have yet to be explored. We report here that coagulases are public goods that confer protection against antimicrobials and immune factors within a local population or community, thus promoting growth and virulence. By utilizing variants of a methicillin-resistantS. aureuswe infer that the secretion of coagulases is a cooperative trait, which is subject to exploitation by invading mutants that do not produce the public goods themselves. However, overexploitation, “tragedy of the commons,” does not occur at clinically relevant conditions. Our micrographs indicate this is due to spatial segregation and population viscosity. These findings emphasize the critical role of coagulases in a social evolution context and provide a possible explanation as to why the secretion of these public goods is maintained in mixedS. aureuscommunities.

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Apolar Bioactive Fraction ofMelipona scutellarisGeopropolis onStreptococcus mutansBiofilm

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2013/256287 ◽

2013 ◽

Vol 2013 ◽

pp. 1-7 ◽

Cited By ~ 12

Author(s):

Marcos Guilherme da Cunha ◽

Marcelo Franchin ◽

Lívia Câmara de Carvalho Galvão ◽

Bruno Bueno-Silva ◽

Masaharu Ikegaki ◽

...

Keyword(s):

Electron Microscopy ◽

Biofilm Formation ◽

Microbial Population ◽

Ethanolic Extract ◽

Vehicle Control ◽

Sem Images ◽

Killing Assay ◽

Bioactive Fraction ◽

Biofilm Matrix ◽

Scanning Electron

The aim of this study was to evaluate the influence of the bioactive nonpolar fraction of geopropolis onStreptococcus mutansbiofilm. The ethanolic extract ofMelipona scutellarisgeopropolis was subjected to a liquid-liquid partition, thus obtaining the bioactive hexane fraction (HF) possessing antimicrobial activity. The effects of HF onS. mutansUA159 biofilms generated on saliva-coated hydroxyapatite discs were analyzed by inhibition of formation, killing assay, and glycolytic pH-drop assays. Furthermore, biofilms treated with vehicle control and HF were analyzed by scanning electron microscopy (SEM). HF at 250 μg/mL and 400 μg/mL caused 38% and 53% reduction in the biomass of biofilm, respectively, when compared to vehicle control (P<0.05) subsequently observed at SEM images, and this reduction was noticed in the amounts of extracellular alkali-soluble glucans, intracellular iodophilic polysaccharides, and proteins. In addition, theS. mutansviability (killing assay) and acid production by glycolytic pH drop were not affected (P>0.05). In conclusion, the bioactive HF of geopropolis was promising to control theS. mutansbiofilm formation, without affecting the microbial population but interfering with its structure by reducing the biochemical content of biofilm matrix.

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Cheaters shape the evolution of phenotypic heterogeneity in Bacillus subtilis biofilms

10.1101/494716 ◽

2018 ◽

Cited By ~ 1

Author(s):

Marivic Martin ◽

Anna Dragoš ◽

Simon B. Otto ◽

Daniel Schäfer ◽

Susanne Brix ◽

...

Keyword(s):

Bacillus Subtilis ◽

Prolonged Exposure ◽

Adaptive Strategy ◽

Phenotypic Heterogeneity ◽

Structural Proteins ◽

Cell Level ◽

General Adaptation ◽

Matrix Production ◽

Matrix Components

ABSTRACTBiofilms are closely packed cells held and shielded by extracellular matrix composed of structural proteins and exopolysaccharides (EPS). As matrix components are costly to produce and shared within the population, EPS-deficient cells can act as cheaters by gaining benefits from the cooperative nature of EPS producers. Remarkably, genetically programmed EPS producers can also exhibit phenotypic heterogeneity at single cell level. Previous studies have shown that spatial structure of biofilms limits the spread of cheaters, but the long-term influence of cheating on biofilm evolution is not well understood. Here, we examine the influence of EPS non-producers on evolution of matrix production within the populations of EPS producers in a model biofilm-forming bacterium, Bacillus subtilis. We discovered that general adaptation to biofilm lifestyle leads to an increase in phenotypical heterogeneity of eps expression. Apparently, prolonged exposure to EPS-deficient cheaters, may result in different adaptive strategy, where eps expression increases uniformly within the population. We propose a molecular mechanism behind such adaptive strategy and demonstrate how it can benefit the EPS-producers in the presence of cheaters. This study provides additional insights on how biofilms adapt and respond to stress caused by exploitation in long-term scenario.

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