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Ábrahám Á, Dér L, Csákvári E, Vizsnyiczai G, Pap I, Lukács R, Varga-Zsíros V, Nagy K, Galajda P. Single-cell level LasR-mediated quorum sensing response of Pseudomonas aeruginosa to pulses of signal molecules. Sci Rep 2024; 14:16181. [PMID: 39003361 PMCID: PMC11246452 DOI: 10.1038/s41598-024-66706-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Accepted: 07/03/2024] [Indexed: 07/15/2024] Open
Abstract
Quorum sensing (QS) is a communication form between bacteria via small signal molecules that enables global gene regulation as a function of cell density. We applied a microfluidic mother machine to study the kinetics of the QS response of Pseudomonas aeruginosa bacteria to additions and withdrawals of signal molecules. We traced the fast buildup and the subsequent considerably slower decay of a population-level and single-cell-level QS response. We applied a mathematical model to explain the results quantitatively. We found significant heterogeneity in QS on the single-cell level, which may result from variations in quorum-controlled gene expression and protein degradation. Heterogeneity correlates with cell lineage history, too. We used single-cell data to define and quantitatively characterize the population-level quorum state. We found that the population-level QS response is well-defined. The buildup of the quorum is fast upon signal molecule addition. At the same time, its decay is much slower following signal withdrawal, and the quorum may be maintained for several hours in the absence of the signal. Furthermore, the quorum sensing response of the population was largely repeatable in subsequent pulses of signal molecules.
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Affiliation(s)
- Ágnes Ábrahám
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
- Doctoral School of Multidisciplinary Medical Sciences, University of Szeged, Dóm Tér 9, Szeged, 6720, Hungary
| | - László Dér
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Eszter Csákvári
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
- Division for Biotechnology, Bay Zoltán Nonprofit Ltd. for Applied Research, Derkovits Fasor 2., Szeged, 6726, Hungary
| | - Gaszton Vizsnyiczai
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Imre Pap
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
- Doctoral School of Multidisciplinary Medical Sciences, University of Szeged, Dóm Tér 9, Szeged, 6720, Hungary
| | - Rebeka Lukács
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Vanda Varga-Zsíros
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary
- HUN-REN Biological Research Centre, Institute of Biochemistry, Temesvári Krt. 62, Szeged, 6726, Hungary
| | - Krisztina Nagy
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary.
| | - Péter Galajda
- HUN-REN Biological Research Centre, Institute of Biophysics, Temesvári Krt. 62, Szeged, 6726, Hungary.
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2
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Huijboom L, Rashtchi P, Tempelaars M, Boeren S, van der Linden E, Habibi M, Abee T. Phenotypic and proteomic differences in biofilm formation of two Lactiplantibacillus plantarum strains in static and dynamic flow environments. Biofilm 2024; 7:100197. [PMID: 38706985 PMCID: PMC11066574 DOI: 10.1016/j.bioflm.2024.100197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Revised: 04/09/2024] [Accepted: 04/10/2024] [Indexed: 05/07/2024] Open
Abstract
Lactiplantibacillus plantarum is a Gram-positive non-motile bacterium capable of producing biofilms that contribute to the colonization of surfaces in a range of different environments. In this study, we compared two strains, WCFS1 and CIP104448, in their ability to produce biofilms in static and dynamic (flow) environments using an in-house designed flow setup. This flow setup enables us to impose a non-uniform flow velocity profile across the well. Biofilm formation occurred at the bottom of the well for both strains, under static and flow conditions, where in the latter condition, CIP104448 also showed increased biofilm formation at the walls of the well in line with the higher hydrophobicity of the cells and the increased initial attachment efficacy compared to WCFS1. Fluorescence and scanning electron microscopy showed open 3D structured biofilms formed under flow conditions, containing live cells and ∼30 % damaged/dead cells for CIP104448, whereas the WCFS1 biofilm showed live cells closely packed together. Comparative proteome analysis revealed minimal changes between planktonic and static biofilm cells of the respective strains suggesting that biofilm formation within 24 h is merely a passive process. Notably, observed proteome changes in WCFS1 and CIP104448 flow biofilm cells indicated similar and unique responses including changes in metabolic activity, redox/electron transfer and cell division proteins for both strains, and myo-inositol production for WCFS1 and oxidative stress response and DNA damage repair for CIP104448 uniquely. Exposure to DNase and protease treatments as well as lethal concentrations of peracetic acid showed highest resistance of flow biofilms. For the latter, CIP104448 flow biofilm even maintained its high disinfectant resistance after dispersal from the bottom and from the walls of the well. Combining all results highlights that L. plantarum biofilm structure and matrix, and physiological state and stress resistance of cells is strain dependent and strongly affected under flow conditions. It is concluded that consideration of effects of flow on biofilm formation is essential to better understand biofilm formation in different settings, including food processing environments.
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Affiliation(s)
- Linda Huijboom
- Food Microbiology, Wageningen University, Wageningen, 6708WG, the Netherlands
| | - Parisa Rashtchi
- Physics and Physical Chemistry of Foods, Wageningen University, Wageningen, 6708WG, the Netherlands
| | - Marcel Tempelaars
- Food Microbiology, Wageningen University, Wageningen, 6708WG, the Netherlands
| | - Sjef Boeren
- Biochemistry, Wageningen University, Wageningen, 6708WG, the Netherlands
| | - Erik van der Linden
- Physics and Physical Chemistry of Foods, Wageningen University, Wageningen, 6708WG, the Netherlands
| | - Mehdi Habibi
- Physics and Physical Chemistry of Foods, Wageningen University, Wageningen, 6708WG, the Netherlands
| | - Tjakko Abee
- Food Microbiology, Wageningen University, Wageningen, 6708WG, the Netherlands
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3
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Scarinci G, Sourjik V. Impact of direct physical association and motility on fitness of a synthetic interkingdom microbial community. THE ISME JOURNAL 2023; 17:371-381. [PMID: 36566339 PMCID: PMC9938286 DOI: 10.1038/s41396-022-01352-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 12/08/2022] [Accepted: 12/13/2022] [Indexed: 12/25/2022]
Abstract
Mutualistic exchange of metabolites can play an important role in microbial communities. Under natural environmental conditions, such exchange may be compromised by the dispersal of metabolites and by the presence of non-cooperating microorganisms. Spatial proximity between members during sessile growth on solid surfaces has been shown to promote stabilization of cross-feeding communities against these challenges. Nonetheless, many natural cross-feeding communities are not sessile but rather pelagic and exist in turbulent aquatic environments, where partner proximity is often achieved via direct cell-cell adhesion, and cooperation occurs between physically associated cells. Partner association in aquatic environments could be further enhanced by motility of individual planktonic microorganisms. In this work, we establish a model bipartite cross-feeding community between bacteria and yeast auxotrophs to investigate the impact of direct adhesion between prokaryotic and eukaryotic partners and of bacterial motility in a stirred mutualistic co-culture. We demonstrate that adhesion can provide fitness benefit to the bacterial partner, likely by enabling local metabolite exchange within co-aggregates, and that it counteracts invasion of the community by a non-cooperating cheater strain. In a turbulent environment and at low cell densities, fitness of the bacterial partner and its competitiveness against a non-cooperating strain are further increased by motility that likely facilitates partner encounters and adhesion. These results suggest that, despite their potential fitness costs, direct adhesion between partners and its enhancement by motility may play key roles as stabilization factors for metabolic communities in turbulent aquatic environments.
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Affiliation(s)
- Giovanni Scarinci
- grid.419554.80000 0004 0491 8361Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany
| | - Victor Sourjik
- Max Planck Institute for Terrestrial Microbiology and Center for Synthetic Microbiology (SYNMIKRO), Marburg, Germany.
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4
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Lactobacillus plantarum strains show diversity in biofilm formation under flow conditions. Heliyon 2022; 8:e12602. [PMID: 36619453 PMCID: PMC9816783 DOI: 10.1016/j.heliyon.2022.e12602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 05/13/2022] [Accepted: 12/15/2022] [Indexed: 12/26/2022] Open
Abstract
In many natural and technological applications, microbial biofilms grow under fluid flow. In this project, we investigated the influence of flow on the formation and growth of biofilms produced by gram-positive Lactobacillus plantarum strains WCFS1 and CIP104448. We used an in-house designed device based on a 48-well plate with culture volumes of 0.8 ml, and quantified total biofilm formation under static and flow conditions with flow rates 0.8, 1.6, 3.2 and 4.8 ml/h (with 1, 2, 4 and 6 volume changes per hour) using crystal violet (CV) staining, and determined the number of viable biofilm cells based on plate counts. The amount of total biofilm under flow conditions increased in the CIP 104448 strain, with significantly increased staining at the wall of the wells. However, in the WCFS1 strain, no significant difference in the amount of biofilm formed under flow and static conditions was observed. Plate counts showed that flow caused an increase in the number of viable biofilm cells for both strains. In addition, using enzyme treatment experiments, we found that for WCFS1 in the static condition, the amount of mature biofilm was declined after DNase I and Proteinase K treatment, while for flow conditions, the decline was only observed for DNase I treatment. The CIP104448 biofilms formed under both static and flow conditions only showed a decline in the CV staining after adding Proteinase K, indicating different contributions of extracellular DNA (eDNA) and proteinaceous matrix components to biofilm formation in the tested strains.
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Caldara M, Belgiovine C, Secchi E, Rusconi R. Environmental, Microbiological, and Immunological Features of Bacterial Biofilms Associated with Implanted Medical Devices. Clin Microbiol Rev 2022; 35:e0022120. [PMID: 35044203 PMCID: PMC8768833 DOI: 10.1128/cmr.00221-20] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
The spread of biofilms on medical implants represents one of the principal triggers of persistent and chronic infections in clinical settings, and it has been the subject of many studies in the past few years, with most of them focused on prosthetic joint infections. We review here recent works on biofilm formation and microbial colonization on a large variety of indwelling devices, ranging from heart valves and pacemakers to urological and breast implants and from biliary stents and endoscopic tubes to contact lenses and neurosurgical implants. We focus on bacterial abundance and distribution across different devices and body sites and on the role of environmental features, such as the presence of fluid flow and properties of the implant surface, as well as on the interplay between bacterial colonization and the response of the human immune system.
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Affiliation(s)
- Marina Caldara
- Interdepartmental Center on Safety, Technologies, and Agri-food Innovation (SITEIA.PARMA), University of Parma, Parma, Italy
| | - Cristina Belgiovine
- IRCCS Humanitas Research Hospital, Rozzano–Milan, Italy
- Scuola di Specializzazione in Microbiologia e Virologia, Università degli Studi di Pavia, Pavia, Italy
| | - Eleonora Secchi
- Institute of Environmental Engineering, ETH Zürich, Zürich, Switzerland
| | - Roberto Rusconi
- IRCCS Humanitas Research Hospital, Rozzano–Milan, Italy
- Department of Biomedical Sciences, Humanitas University, Pieve Emanuele–Milan, Italy
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6
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Abstract
African trypanosomes are responsible for important diseases of humans and animals in sub-Saharan Africa. The best-studied species is Trypanosoma brucei, which is characterized by development in the mammalian host between morphologically slender and stumpy forms. The latter are adapted for transmission by the parasite's vector, the tsetse fly. The development of stumpy forms is driven by density-dependent quorum-sensing (QS), the molecular basis for which is now coming to light. In this review, I discuss the historical context and biological features of trypanosome QS and how it contributes to the parasite's infection dynamics within its mammalian host. Also, I discuss how QS can be lost in different trypanosome species, such as T. brucei evansi and T. brucei equiperdum, or modulated when parasites find themselves competing with others of different genotypes or of different trypanosome species in the same host. Finally, I consider the potential to exploit trypanosome QS therapeutically. Expected final online publication date for the Annual Review of Microbiology, Volume 75 is October 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Keith R Matthews
- Institute for Immunology and Infection Research, Ashworth Laboratories, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3FL, United Kingdom;
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7
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Pu H, Xu Y, Lin L, Sun D. Biofilm formation of
Pectobacterium
carotovorum
subsp.
carotovorum
on polypropylene surface during multiple cycles of vacuum cooling. Int J Food Sci Technol 2021. [DOI: 10.1111/ijfs.14976] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Hongbin Pu
- School of Food Science and Engineering South China University of Technology Guangzhou510641China
- Academy of Contemporary Food Engineering South China University of Technology, Guangzhou Higher Education Mega Center Guangzhou510006China
- Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, & Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products Guangzhou Higher Education Mega Centre Guangzhou510006China
| | - Yiwen Xu
- School of Food Science and Engineering South China University of Technology Guangzhou510641China
- Academy of Contemporary Food Engineering South China University of Technology, Guangzhou Higher Education Mega Center Guangzhou510006China
- Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, & Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products Guangzhou Higher Education Mega Centre Guangzhou510006China
| | - Lian Lin
- School of Food Science and Engineering South China University of Technology Guangzhou510641China
- Academy of Contemporary Food Engineering South China University of Technology, Guangzhou Higher Education Mega Center Guangzhou510006China
- Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, & Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products Guangzhou Higher Education Mega Centre Guangzhou510006China
| | - Da‐Wen Sun
- School of Food Science and Engineering South China University of Technology Guangzhou510641China
- Academy of Contemporary Food Engineering South China University of Technology, Guangzhou Higher Education Mega Center Guangzhou510006China
- Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, & Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products Guangzhou Higher Education Mega Centre Guangzhou510006China
- Food Refrigeration and Computerized Food Technology (FRCFT) Agriculture and Food Science Centre University College Dublin National University of Ireland Belfield, Dublin 4 Ireland
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8
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Romero PE, Calla-Quispe E, Castillo-Vilcahuaman C, Yokoo M, Fuentes-Rivera HL, Ramirez JL, Ampuero A, Ibáñez AJ, Wong P. From the Andes to the desert: 16S rRNA metabarcoding characterization of aquatic bacterial communities in the Rimac river, the main source of water for Lima, Peru. PLoS One 2021; 16:e0250401. [PMID: 33886647 PMCID: PMC8061919 DOI: 10.1371/journal.pone.0250401] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 04/06/2021] [Indexed: 01/04/2023] Open
Abstract
The Rimac river is the main source of water for Lima, Peru's capital megacity. The river is constantly affected by different types of contamination including mine tailings in the Andes and urban sewage in the metropolitan area. In this work, we aim to produce the first characterization of aquatic bacterial communities in the Rimac river using a 16S rRNA metabarcoding approach which would be useful to identify bacterial diversity and potential understudied pathogens. We report a lower diversity in bacterial communities from the Lower Rimac (Metropolitan zone) in comparison to other sub-basins. Samples were generally grouped according to their geographical location. Bacterial classes Alphaproteobacteria, Bacteroidia, Campylobacteria, Fusobacteriia, and Gammaproteobacteria were the most frequent along the river. Arcobacter cryaerophilus (Campylobacteria) was the most frequent species in the Lower Rimac while Flavobacterium succinicans (Bacteroidia) and Hypnocyclicus (Fusobacteriia) were the most predominant in the Upper Rimac. Predicted metabolic functions in the microbiota include bacterial motility and quorum sensing. Additional metabolomic analyses showed the presence of some insecticides and herbicides in the Parac-Upper Rimac and Santa Eulalia-Parac sub-basins. The dominance in the Metropolitan area of Arcobacter cryaerophilus, an emergent pathogen associated with fecal contamination and antibiotic multiresistance, that is not usually reported in traditional microbiological quality assessments, highlights the necessity to apply next-generation sequencing tools to improve pathogen surveillance. We believe that our study will encourage the integration of omics sciences in Peru and its application on current environmental and public health issues.
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Affiliation(s)
- Pedro E Romero
- Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Erika Calla-Quispe
- Instituto de Ciencias Ómicas y Biotecnología Aplicada (ICOBA), Pontificia Universidad Católica del Peru, Lima, Peru
| | - Camila Castillo-Vilcahuaman
- Departamento de Ciencias Biológicas y Fisiológicas, Facultad de Ciencias y Filosofia, Universidad Peruana Cayetano Heredia, Lima, Peru
| | - Mateo Yokoo
- Departamento de Ciencias de la Medicina, Facultad de Medicina Humana, Universidad de Piura, Lima, Peru
| | - Hammerly Lino Fuentes-Rivera
- Instituto de Ciencias Ómicas y Biotecnología Aplicada (ICOBA), Pontificia Universidad Católica del Peru, Lima, Peru
| | - Jorge L Ramirez
- Departamento de Biología Celular y Genética, Facultad de Ciencias Biológicas, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - André Ampuero
- Departamento de Malacología y Carcinología, Museo de Historia Natural, Universidad Nacional Mayor de San Marcos, Lima, Peru
| | - Alfredo J Ibáñez
- Instituto de Ciencias Ómicas y Biotecnología Aplicada (ICOBA), Pontificia Universidad Católica del Peru, Lima, Peru
| | - Paolo Wong
- Departamento de Ciencias de la Medicina, Facultad de Medicina Humana, Universidad de Piura, Lima, Peru
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van Gestel J, Bareia T, Tenennbaum B, Dal Co A, Guler P, Aframian N, Puyesky S, Grinberg I, D’Souza GG, Erez Z, Ackermann M, Eldar A. Short-range quorum sensing controls horizontal gene transfer at micron scale in bacterial communities. Nat Commun 2021; 12:2324. [PMID: 33875666 PMCID: PMC8055654 DOI: 10.1038/s41467-021-22649-4] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 03/17/2021] [Indexed: 02/02/2023] Open
Abstract
In bacterial communities, cells often communicate by the release and detection of small diffusible molecules, a process termed quorum-sensing. Signal molecules are thought to broadly diffuse in space; however, they often regulate traits such as conjugative transfer that strictly depend on the local community composition. This raises the question how nearby cells within the community can be detected. Here, we compare the range of communication of different quorum-sensing systems. While some systems support long-range communication, we show that others support a form of highly localized communication. In these systems, signal molecules propagate no more than a few microns away from signaling cells, due to the irreversible uptake of the signal molecules from the environment. This enables cells to accurately detect micron scale changes in the community composition. Several mobile genetic elements, including conjugative elements and phages, employ short-range communication to assess the fraction of susceptible host cells in their vicinity and adaptively trigger horizontal gene transfer in response. Our results underscore the complex spatial biology of bacteria, which can communicate and interact at widely different spatial scales.
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Affiliation(s)
- Jordi van Gestel
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland ,grid.418656.80000 0001 1551 0562Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland ,grid.7400.30000 0004 1937 0650Department of Evolutionary Biology and Environmental Studies, University of Zürich, Zürich, Switzerland ,grid.419765.80000 0001 2223 3006Swiss Institute of Bioinformatics, Lausanne, Switzerland ,grid.266102.10000 0001 2297 6811Present Address: Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA USA
| | - Tasneem Bareia
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
| | - Bar Tenennbaum
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
| | - Alma Dal Co
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland ,grid.418656.80000 0001 1551 0562Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland ,grid.38142.3c000000041936754XSchool of Engineering and Applied Sciences, Harvard University, Cambridge, MA USA
| | - Polina Guler
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
| | - Nitzan Aframian
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
| | - Shani Puyesky
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
| | - Ilana Grinberg
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
| | - Glen G. D’Souza
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland ,grid.418656.80000 0001 1551 0562Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland
| | - Zohar Erez
- grid.13992.300000 0004 0604 7563Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel
| | - Martin Ackermann
- grid.5801.c0000 0001 2156 2780Department of Environmental Systems Science, ETH Zürich, Zürich, Switzerland ,grid.418656.80000 0001 1551 0562Department of Environmental Microbiology, Swiss Federal Institute of Aquatic Science and Technology (Eawag), Dübendorf, Switzerland
| | - Avigdor Eldar
- grid.12136.370000 0004 1937 0546The Shmunis School of Biomedicine and Cancer Research, Tel-Aviv University, Tel-Aviv, Israel
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10
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Abstract
Bacteria use intercellular signaling, or quorum sensing (QS), to share information and respond collectively to aspects of their surroundings. The autoinducers that carry this information are exposed to the external environment; consequently, they are affected by factors such as removal through fluid flow, a ubiquitous feature of bacterial habitats ranging from the gut and lungs to lakes and oceans. To understand how QS genetic architectures in cells promote appropriate population-level phenotypes throughout the bacterial life cycle requires knowledge of how these architectures determine the QS response in realistic spatiotemporally varying flow conditions. Here we develop and apply a general theory that identifies and quantifies the conditions required for QS activation in fluid flow by systematically linking cell- and population-level genetic and physical processes. We predict that when a subset of the population meets these conditions, cell-level positive feedback promotes a robust collective response by overcoming flow-induced autoinducer concentration gradients. By accounting for a dynamic flow in our theory, we predict that positive feedback in cells acts as a low-pass filter at the population level in oscillatory flow, allowing a population to respond only to changes in flow that occur over slow enough timescales. Our theory is readily extendable and provides a framework for assessing the functional roles of diverse QS network architectures in realistic flow conditions.
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Affiliation(s)
- Mohit P Dalwadi
- Mathematical Institute, University of Oxford, Oxford OX2 6GG, United Kingdom;
| | - Philip Pearce
- Department of Systems Biology, Harvard Medical School, Boston, MA 02115
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11
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Ostovar G, Naughton KL, Boedicker JQ. Computation in bacterial communities. Phys Biol 2020; 17:061002. [PMID: 33035198 DOI: 10.1088/1478-3975/abb257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Bacteria across many scales are involved in a dynamic process of information exchange to coordinate activity and community structure within large and diverse populations. The molecular components bacteria use to communicate have been discovered and characterized, and recent efforts have begun to understand the potential for bacterial signal exchange to gather information from the environment and coordinate collective behaviors. Such computations made by bacteria to coordinate the action of a population of cells in response to information gathered by a multitude of inputs is a form of collective intelligence. These computations must be robust to fluctuations in both biological, chemical, and physical parameters as well as to operate with energetic efficiency. Given these constraints, what are the limits of computation by bacterial populations and what strategies have evolved to ensure bacterial communities efficiently work together? Here the current understanding of information exchange and collective decision making that occur in microbial populations will be reviewed. Looking toward the future, we consider how a deeper understanding of bacterial computation will inform future direction in microbiology, biotechnology, and biophysics.
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Affiliation(s)
- Ghazaleh Ostovar
- Department of Physics and Astronomy, University of Southern California, Los Angeles, CA 90089, United States of America
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12
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Jung H, Meile CD. Numerical investigation of microbial quorum sensing under various flow conditions. PeerJ 2020; 8:e9942. [PMID: 32983649 PMCID: PMC7500354 DOI: 10.7717/peerj.9942] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2020] [Accepted: 08/24/2020] [Indexed: 11/22/2022] Open
Abstract
Microorganisms efficiently coordinate phenotype expressions through a decision-making process known as quorum sensing (QS). We investigated QS amongst distinct, spatially distributed microbial aggregates under various flow conditions using a process-driven numerical model. Model simulations assess the conditions suitable for QS induction and quantify the importance of advective transport of signaling molecules. In addition, advection dilutes signaling molecules so that faster flow conditions require higher microbial densities, faster signal production rates, or higher sensitivities to signaling molecules to induce QS. However, autoinduction of signal production can substantially increase the transport distance of signaling molecules in both upstream and downstream directions. We present empirical approximations to the solutions of the advection–diffusion–reaction equation that describe the concentration profiles of signaling molecules for a wide range of flow and reaction rates. These empirical relationships, which predict the distribution of dissolved solutes along pore channels, allow to quantitatively estimate the effective communication distances amongst multiple microbial aggregates without further numerical simulations.
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13
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Aframian N, Eldar A. A Bacterial Tower of Babel: Quorum-Sensing Signaling Diversity and Its Evolution. Annu Rev Microbiol 2020; 74:587-606. [PMID: 32680450 DOI: 10.1146/annurev-micro-012220-063740] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Quorum sensing is a process in which bacteria secrete and sense a diffusible molecule, thereby enabling bacterial groups to coordinate their behavior in a density-dependent manner. Quorum sensing has evolved multiple times independently, utilizing different molecular pathways and signaling molecules. A common theme among many quorum-sensing families is their wide range of signaling diversity-different variants within a family code for different signal molecules with a cognate receptor specific to each variant. This pattern of vast allelic polymorphism raises several questions-How do different signaling variants interact with one another? How is this diversity maintained? And how did it come to exist in the first place? Here we argue that social interactions between signaling variants can explain the emergence and persistence of signaling diversity throughout evolution. Finally, we extend the discussion to include cases where multiple diverse systems work in concert in a single bacterium.
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Affiliation(s)
- Nitzan Aframian
- Faculty of Life Sciences, School of Molecular Cell Biology and Biotechnology, Tel-Aviv University, 6997801 Tel-Aviv, Israel; ,
| | - Avigdor Eldar
- Faculty of Life Sciences, School of Molecular Cell Biology and Biotechnology, Tel-Aviv University, 6997801 Tel-Aviv, Israel; ,
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14
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Ge C, Sheng H, Chen X, Shen X, Sun X, Yan Y, Wang J, Yuan Q. Quorum Sensing System Used as a Tool in Metabolic Engineering. Biotechnol J 2020; 15:e1900360. [DOI: 10.1002/biot.201900360] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/07/2020] [Indexed: 12/29/2022]
Affiliation(s)
- Chang Ge
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
| | - Huakang Sheng
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
| | - Xin Chen
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
| | - Xiaolin Shen
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
| | - Xinxiao Sun
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
| | - Yajun Yan
- College of EngineeringThe University of Georgia Athens GA 30605 USA
| | - Jia Wang
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
| | - Qipeng Yuan
- State Key Laboratory of Chemical Resource EngineeringBeijing University of Chemical Technology Beijing Chaoyang 100029 China
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15
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Tan CAZ, Antypas H, Kline KA. Overcoming the challenge of establishing biofilms in vivo: a roadmap for Enterococci. Curr Opin Microbiol 2020; 53:9-18. [PMID: 32062025 DOI: 10.1016/j.mib.2020.01.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 01/10/2020] [Accepted: 01/15/2020] [Indexed: 12/28/2022]
Abstract
Enterococcus faecalis forms single and mixed-species biofilms on both tissue and medical devices in the host, often under exposure to fluid flow, giving rise to infections that are recalcitrant to treatment. The factors that drive enterococcal biofilm formation in the host, however, remain unclear. Recent reports in other pathogens show how surface sensing by bacteria can trigger the transition from planktonic to sessile lifestyle. Fluid flow can enhance initial adhesion, but also influence quorum sensing. Biofilm-specific factors, as well as biofilm size and extracellular polymeric substances, can compromise opsonization and phagocytosis. Bacterial interspecies synergy can create favorable conditions in the host for biofilm formation. Through these concepts, we define the knowledge gaps in understanding host-associated E. faecalis biofilm formation and propose a roadmap for future investigations.
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Affiliation(s)
- Casandra Ai Zhu Tan
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Haris Antypas
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore
| | - Kimberly A Kline
- Singapore Centre for Environmental Life Sciences Engineering, School of Biological Sciences, Nanyang Technological University, Singapore.
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16
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Wheeler JD, Secchi E, Rusconi R, Stocker R. Not Just Going with the Flow: The Effects of Fluid Flow on Bacteria and Plankton. Annu Rev Cell Dev Biol 2019; 35:213-237. [PMID: 31412210 DOI: 10.1146/annurev-cellbio-100818-125119] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Microorganisms often live in habitats characterized by fluid flow, from lakes and oceans to soil and the human body. Bacteria and plankton experience a broad range of flows, from the chaotic motion characteristic of turbulence to smooth flows at boundaries and in confined environments. Flow creates forces and torques that affect the movement, behavior, and spatial distribution of microorganisms and shapes the chemical landscape on which they rely for nutrient acquisition and communication. Methodological advances and closer interactions between physicists and biologists have begun to reveal the importance of flow-microorganism interactions and the adaptations of microorganisms to flow. Here we review selected examples of such interactions from bacteria, phytoplankton, larvae, and zooplankton. We hope that this article will serve as a blueprint for a more in-depth consideration of the effects of flow in the biology of microorganisms and that this discussion will stimulate further multidisciplinary effort in understanding this important component of microorganism habitats.
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Affiliation(s)
- Jeanette D Wheeler
- Institute of Environmental Engineering, Department of Civil, Environmental, and Geomatic Engineering, ETH Zürich, 8093 Zürich, Switzerland;
| | - Eleonora Secchi
- Institute of Environmental Engineering, Department of Civil, Environmental, and Geomatic Engineering, ETH Zürich, 8093 Zürich, Switzerland;
| | - Roberto Rusconi
- Department of Biomedical Sciences, Humanitas University, 20090 Pieve Emanuele (MI), Italy.,Humanitas Clinical and Research Center-IRCCS, 20089 Rozzano (MI), Italy
| | - Roman Stocker
- Institute of Environmental Engineering, Department of Civil, Environmental, and Geomatic Engineering, ETH Zürich, 8093 Zürich, Switzerland;
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17
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Bruce JB, West SA, Griffin AS. Functional amyloids promote retention of public goods in bacteria. Proc Biol Sci 2019; 286:20190709. [PMID: 31138071 DOI: 10.1098/rspb.2019.0709] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
The growth and virulence of bacteria depends upon a number of factors that are secreted into the environment. These factors can diffuse away from the producing cells, to be either lost or used by cells that do not produce them (cheats). Mechanisms that act to reduce the loss of secreted factors through diffusion are expected to be favoured. One such mechanism may be the production of Fap fibrils, needle-like fibres on the cell surface observed in P. aeruginosa, which can transiently bind several secreted metabolites produced by cells. We test whether Fap fibrils help retain a secreted factor, the iron-scavenging molecule pyoverdine, and hence reduce the potential for exploitation by non-producing, cheating cells. We found that: (i) wild-type cells retain more iron-chelating metabolites than fibril non-producers; (ii) purified Fap fibrils can prevent the loss of the iron-chelators PQS ( Pseudomonas quinolone signal) and pyoverdine; and (iii) pyoverdine non-producers have higher fitness in competition with fibril non-producers than with wild-type cells. Our results suggest that by limiting the loss of a costly public good, Fap fibrils may play an important role in stabilizing cooperative production of secreted factors.
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Affiliation(s)
- John B Bruce
- Department of Zoology, University of Oxford , Oxford , UK
| | - Stuart A West
- Department of Zoology, University of Oxford , Oxford , UK
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18
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Kim S, Kerns SJ, Ziesack M, Bry L, Gerber GK, Way JC, Silver PA. Quorum Sensing Can Be Repurposed To Promote Information Transfer between Bacteria in the Mammalian Gut. ACS Synth Biol 2018; 7:2270-2281. [PMID: 30125499 DOI: 10.1021/acssynbio.8b00271] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The gut microbiome is intricately involved with establishing and maintaining the health of the host. Engineering of gut microbes aims to add new functions and expand the scope of control over the gut microbiome. To create systems that can perform increasingly complex tasks in the gut, it is necessary to harness the ability of the bacteria to communicate in the gut environment. Interestingly, acyl-homoserine lactone (acyl-HSL)-mediated Gram-negative bacterial quorum sensing, a widely used mode of intercellular signaling system in nature, has not been identified in normal healthy mammalian gut. It remains unknown whether the gut bacteria that do not natively use quorum sensing can be engineered to successfully signal to other bacteria using acyl-HSLs in the gut environment. Here, we repurposed quorum sensing to create an information transfer system between native gut Escherichia coli and attenuated Salmonella enterica serovar Typhimurium. Specifically, we functionalized one species with inducible signal production and the other with signal detection and recording using genomically integrated circuits. The information transfer system demonstrated successful intra- and interspecies signaling in the murine gut. This study provides a basis for further understanding of interbacterial interactions in an otherwise hard-to-study environment as well as a basis for further investigation of the potential of acyl-HSLs as intercellular signaling molecules of engineered gut consortia.
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Affiliation(s)
- Suhyun Kim
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, United States
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
| | - S. Jordan Kerns
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
| | - Marika Ziesack
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
| | - Lynn Bry
- Department of Pathology, Brigham and Women’s Hospital, Boston, Massachusetts 02115, United States
| | - Georg K. Gerber
- Department of Pathology, Brigham and Women’s Hospital, Boston, Massachusetts 02115, United States
| | - Jeffrey C. Way
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
| | - Pamela A. Silver
- Department of Systems Biology, Harvard Medical School, Boston, Massachusetts 02115, United States
- Wyss Institute for Biologically Inspired Engineering, Harvard University, Boston, Massachusetts 02115, United States
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Lowe-Power TM, Khokhani D, Allen C. How Ralstonia solanacearum Exploits and Thrives in the Flowing Plant Xylem Environment. Trends Microbiol 2018; 26:929-942. [PMID: 29941188 DOI: 10.1016/j.tim.2018.06.002] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 05/24/2018] [Accepted: 06/04/2018] [Indexed: 10/28/2022]
Abstract
The plant wilt pathogen Ralstonia solanacearum thrives in the water-transporting xylem vessels of its host plants. Xylem is a relatively nutrient-poor, high-flow environment but R. solanacearum succeeds there by tuning its own metabolism and altering xylem sap biochemistry. Flow influences many traits that the bacterium requires for pathogenesis. Most notably, a quorum sensing system mediates the pathogen's major transition from a rapidly dividing early phase that voraciously consumes diverse food sources and avidly adheres to plant surfaces to a slower-growing late phase that can use fewer nutrients but produces virulence factors and disperses effectively. This review discusses recent findings about R. solanacearum pathogenesis in the context of its flowing in planta niche, with emphasis on R. solanacearum metabolism in plants.
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Affiliation(s)
- Tiffany M Lowe-Power
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, USA; Current address: Department of Plant and Microbial Biology, University of California-Berkeley, Berkeley, CA 94720, USA
| | - Devanshi Khokhani
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, USA; Current address: Department of Bacteriology, University of Wisconsin-Madison, Madison, WI 53706, USA
| | - Caitilyn Allen
- Department of Plant Pathology, University of Wisconsin-Madison, Madison, WI 53706, USA.
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20
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Conrad JC, Poling-Skutvik R. Confined Flow: Consequences and Implications for Bacteria and Biofilms. Annu Rev Chem Biomol Eng 2018; 9:175-200. [DOI: 10.1146/annurev-chembioeng-060817-084006] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Bacteria overwhelmingly live in geometrically confined habitats that feature small pores or cavities, narrow channels, or nearby interfaces. Fluid flows through these confined habitats are ubiquitous in both natural and artificial environments colonized by bacteria. Moreover, these flows occur on time and length scales comparable to those associated with motility of bacteria and with the formation and growth of biofilms, which are surface-associated communities that house the vast majority of bacteria to protect them from host and environmental stresses. This review describes the emerging understanding of how flow near surfaces and within channels and pores alters physical processes that control how bacteria disperse, attach to surfaces, and form biofilms. This understanding will inform the development and deployment of technologies for drug delivery, water treatment, and antifouling coatings and guide the structuring of bacterial consortia for production of chemicals and pharmaceuticals.
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Affiliation(s)
- Jacinta C. Conrad
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, USA
| | - Ryan Poling-Skutvik
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, USA
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21
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Farrell C, Hassard F, Jefferson B, Leziart T, Nocker A, Jarvis P. Turbidity composition and the relationship with microbial attachment and UV inactivation efficacy. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 624:638-647. [PMID: 29272833 DOI: 10.1016/j.scitotenv.2017.12.173] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/14/2017] [Accepted: 12/15/2017] [Indexed: 06/07/2023]
Abstract
Turbidity in water can be caused by a range of different turbidity causing materials (TCM). Here the characteristics and attachment of bacteria to TCMs was assessed and the resultant impact on UV disinfection determined. TCMs represent potential vehicles for bacterial penetration of water treatment barriers, contamination of potable supplies and impact on subsequent human health. The TCMs under investigation were representative of those that may be present in surface and ground waters, both from the source and formed in the treatment process. The TCMs were chalk, Fe (III) hydroxide precipitate, kaolin clay, manganese dioxide and humic acids, at different turbidity levels representative of source waters (0, 0.1, 0.2, 0.4, 1, 2, and 5 NTU). Escherichia coli and Enterococcus faecalis attachment followed the order of Fe(III)>chalk, with little to no attachment seen for MnO2, humic acids and clay. The attachment was postulated to be due to chalk and Fe(III) particles having a more neutral surface charge resulting in elevated aggregation with bacteria compared to other TCMs. The humic acids and Fe(III) were the TCMs which influenced inactivation of E. coli and E. faecalis due to decreasing UV transmittance (UVT) with increasing TCM concentration. The presence of the Fe(III) TCM at 0.2 NTU resulted in the poorest E. coli inactivation, with 2.5 log10 reduction at UV dose of 10mJcm-2 (kd of -0.23cm2mJ-1) compared to a 3.9 log10 reduction in the absence of TCMs. E. faecalis had a greater resistance to UV irradiation than E. coli for all TCMs. Effective disinfection of drinking water is a priority for ensuring high public health standards. Uniform regulations for turbidity levels for waters pre-disinfection by UV light set by regulators may not always be appropriate and efficacy is dependent on the type, as well as the amount, of turbidity present in the water.
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Affiliation(s)
- Charlotte Farrell
- Cranfield Water Science Institute, Cranfield University, Bedfordshire MK43 0AL, UK
| | - Francis Hassard
- Cranfield Water Science Institute, Cranfield University, Bedfordshire MK43 0AL, UK
| | - Bruce Jefferson
- Cranfield Water Science Institute, Cranfield University, Bedfordshire MK43 0AL, UK
| | - Tangui Leziart
- Cranfield Water Science Institute, Cranfield University, Bedfordshire MK43 0AL, UK
| | | | - Peter Jarvis
- Cranfield Water Science Institute, Cranfield University, Bedfordshire MK43 0AL, UK.
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Biofilm disruption by an air bubble reveals heterogeneous age-dependent detachment patterns dictated by initial extracellular matrix distribution. NPJ Biofilms Microbiomes 2017. [PMID: 28649407 PMCID: PMC5460265 DOI: 10.1038/s41522-017-0014-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Bacteria often adhere to surfaces, where they form communities known as biofilms. Recently, it has been shown that biofilm formation initiates with the microscopically heterogeneous deposition of a skeleton of extracellular polymeric substances (EPS) by individual cells crawling on the surface, followed by growth of the biofilm into a surface-covering continuum. Here we report microfluidic experiments with Pseudomonas aeruginosa biofilms showing that their "hidden" heterogeneity can affect the later dynamics of their disruption. Using controlled air bubbles as a model for mechanical insult, we demonstrate that biofilm disruption is strongly dependent on biofilm age, and that disruption to early-stage biofilms can take the shape of a semi-regular pattern of ~15 µm diameter holes from which bacteria have been removed. We explain hole formation in terms of the rupture and retreat of the thin liquid layer created by the long bubble, which scrapes bacteria off the surface and rearranges their distribution. We find that the resulting pattern correlates with the spatial distribution of EPS: holes form where there is less EPS, whereas regions with more EPS act as strongholds against the scraping liquid front. These results show that heterogeneity in the microscale EPS skeleton of biofilms has profound consequences for later dynamics, including disruption. Because few attached cells suffice to regrow a biofilm, these results point to the importance of considering microscale heterogeneity when designing and assessing the effectiveness of biofilm removal strategies by mechanical forces.
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