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Vishwakarma A, Narayanan A, Kumar N, Chen Z, Dang F, Menefee J, Dhinojwala A, Joy A. Coacervate Dense Phase Displaces Surface-Established Pseudomonas aeruginosa Biofilms. J Am Chem Soc 2024; 146:26397-26407. [PMID: 39259884 DOI: 10.1021/jacs.4c09311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/13/2024]
Abstract
For millions of years, barnacles and mussels have successfully adhered to wet rocks near tide-swept seashores. While the chemistry and mechanics of their underwater adhesives are being thoroughly investigated, an overlooked aspect of marine organismal adhesion is their ability to remove underlying biofilms from rocks and prepare clean surfaces before the deposition of adhesive anchors. Herein, we demonstrate that nonionic, coacervating synthetic polymers that mimic the physicochemical features of marine underwater adhesives remove ∼99% of Pseudomonas aeruginosa (P. aeruginosa) biofilm biomass from underwater surfaces. The efficiency of biofilm removal appears to align with the compositional differences between various bacterial biofilms. In addition, the surface energy influences the ability of the polymer to displace the biofilm, with biofilm removal efficiency decreasing for surfaces with lower surface energies. These synthetic polymers weaken the biofilm-surface interactions and exert shear stress to fracture the biofilms grown on surfaces with diverse surface energies. Since bacterial biofilms are 1000-fold more tolerant to common antimicrobial agents and pose immense health and economic risks, we anticipate that our unconventional approach inspired by marine underwater adhesion will open a new paradigm in creating antibiofilm agents that target the interfacial and viscoelastic properties of established bacterial biofilms.
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Affiliation(s)
- Apoorva Vishwakarma
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Amal Narayanan
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, United States
| | - Nityanshu Kumar
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Zixi Chen
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
- Department of Bioengineering, Northeastern University, Boston, Massachusetts 02120, United States
| | - Francis Dang
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Joshua Menefee
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Ali Dhinojwala
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
| | - Abraham Joy
- School of Polymer Science and Polymer Engineering, The University of Akron, Akron, Ohio 44325, United States
- Department of Bioengineering, Northeastern University, Boston, Massachusetts 02120, United States
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2
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Charlton SG, Bible AN, Secchi E, Morrell‐Falvey JL, Retterer ST, Curtis TP, Chen J, Jana S. Microstructural and Rheological Transitions in Bacterial Biofilms. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207373. [PMID: 37522628 PMCID: PMC10520682 DOI: 10.1002/advs.202207373] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 06/20/2023] [Indexed: 08/01/2023]
Abstract
Biofilms are aggregated bacterial communities structured within an extracellular matrix (ECM). ECM controls biofilm architecture and confers mechanical resistance against shear forces. From a physical perspective, biofilms can be described as colloidal gels, where bacterial cells are analogous to colloidal particles distributed in the polymeric ECM. However, the influence of the ECM in altering the cellular packing fraction (ϕ) and the resulting viscoelastic behavior of biofilm remains unexplored. Using biofilms of Pantoea sp. (WT) and its mutant (ΔUDP), the correlation between biofilm structure and its viscoelastic response is investigated. Experiments show that the reduction of exopolysaccharide production in ΔUDP biofilms corresponds with a seven-fold increase in ϕ, resulting in a colloidal glass-like structure. Consequently, the rheological signatures become altered, with the WT behaving like a weak gel, whilst the ΔUDP displayed a glass-like rheological signature. By co-culturing the two strains, biofilm ϕ is modulated which allows us to explore the structural changes and capture a change in viscoelastic response from a weak to a strong gel, and to a colloidal glass-like state. The results reveal the role of exopolysaccharide in mediating a structural transition in biofilms and demonstrate a correlation between biofilm structure and viscoelastic response.
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Affiliation(s)
- Samuel G.V. Charlton
- Department of Civil, Environmental and Geomatic EngineeringInstitute of Environmental EngineeringETH ZurichZurich8049Switzerland
- School of EngineeringNewcastle UniversityNewcastle Upon TyneNE1 7RUUK
| | - Amber N. Bible
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTN37830USA
| | - Eleonora Secchi
- Department of Civil, Environmental and Geomatic EngineeringInstitute of Environmental EngineeringETH ZurichZurich8049Switzerland
| | | | - Scott T. Retterer
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTN37830USA
- Center for Nanophase Material SciencesOak Ridge National LaboratoryOak RidgeTN37830USA
| | - Thomas P. Curtis
- School of EngineeringNewcastle UniversityNewcastle Upon TyneNE1 7RUUK
| | - Jinju Chen
- School of EngineeringNewcastle UniversityNewcastle Upon TyneNE1 7RUUK
| | - Saikat Jana
- School of EngineeringNewcastle UniversityNewcastle Upon TyneNE1 7RUUK
- School of EngineeringUlster UniversityBelfastBT15 1APUK
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3
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Oliveira IM, Gomes IB, Plácido A, Simões LC, Eaton P, Simões M. The impact of potassium peroxymonosulphate and chlorinated cyanurates on biofilms of Stenotrophomonas maltophilia: effects on biofilm control, regrowth, and mechanical properties. BIOFOULING 2023; 39:691-705. [PMID: 37811587 DOI: 10.1080/08927014.2023.2254704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/27/2023] [Indexed: 10/10/2023]
Abstract
The activity of two chlorinated isocyanurates (NaDCC and TCCA) and peroxymonosulphate (OXONE) was evaluated against biofilms of Stenotrophomonas maltophilia, an emerging pathogen isolated from drinking water (DW), and for the prevention of biofilm regrowth. After disinfection of pre-formed 48 h-old biofilms, the culturability was reduced up to 7 log, with OXONE, TCCA, and NaDCC showing more efficiency than free chlorine against biofilms formed on stainless steel. The regrowth of biofilms previously exposed to OXONE was reduced by 5 and 4 log CFU cm-2 in comparison to the unexposed biofilms and biofilms exposed to free chlorine, respectively. Rheometry analysis showed that biofilms presented properties of viscoelastic solid materials, regardless of the treatment. OXONE reduced the cohesiveness of the biofilm, given the significant decrease in the complex shear modulus (G*). AFM analysis revealed that biofilms had a fractured appearance and smaller bacterial aggregates dispersed throughout the surface after OXONE exposure than the control sample. In general, OXONE has been demonstrated to be a promising disinfectant to control DW biofilms, with a higher activity than chlorine. The results also show the impact of the biofilm mechanical properties on the efficacy of the disinfectants in biofilm control.
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Affiliation(s)
- I M Oliveira
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Porto, Portugal
- ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Porto, Portugal
| | - I B Gomes
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Porto, Portugal
- ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Porto, Portugal
| | - A Plácido
- REQUIMTE/LAQV - Associated Laboratory for Green Chemistry of the Network of Chemistry and Technology, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Porto, Portugal
| | - L C Simões
- CEB - Centre of Biological Engineering, University of Minho, Braga, Portugal
- LABBELS - Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, Braga/Guimarães, Portugal
| | - P Eaton
- REQUIMTE/LAQV - Associated Laboratory for Green Chemistry of the Network of Chemistry and Technology, Department of Chemistry and Biochemistry, Faculty of Sciences, University of Porto, Porto, Portugal
- The Bridge, School of Chemistry, University of Lincoln, Lincoln, UK
| | - M Simões
- LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Porto, Portugal
- ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Porto, Portugal
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4
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Granato ET, Smith WPJ, Foster KR. Collective protection against the type VI secretion system in bacteria. THE ISME JOURNAL 2023:10.1038/s41396-023-01401-4. [PMID: 37095301 DOI: 10.1038/s41396-023-01401-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 03/11/2023] [Accepted: 03/20/2023] [Indexed: 04/26/2023]
Abstract
Bacteria commonly face attacks from other strains using the type VI secretion system (T6SS), which acts like a molecular speargun to stab and intoxicate competitors. Here we show how bacteria can work together to collectively defend themselves against these attacks. This project began with an outreach activity: while developing an online computer game of bacterial warfare, we noticed that one strategist ("Slimy") that made extracellular polymeric substances (EPS) was able to resist attacks from another strategist that employed the T6SS ("Stabby"). This observation motivated us to model this scenario more formally, using dedicated agent-based simulations. The model predicts that EPS production can serve as a collective defence mechanism, which protects both producing cells and neighbouring cells that do not make EPS. We then tested our model with a synthetic community that contains a T6SS-wielding attacker (Acinetobacter baylyi), and two T6SS-sensitive target strains (Escherichia coli) that either secrete EPS, or not. As predicted by our modelling, we find that the production of EPS leads to collective protection against T6SS attacks, where EPS producers protect each other and nearby non-producers. We identify two processes that explain this protection: EPS sharing between cells and a second general mechanism whereby groups of resistant cells shield susceptible cells, which we call "flank protection". Our work shows how EPS-producing bacteria can work together to defend themselves from the type VI secretion system.
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Affiliation(s)
- Elisa T Granato
- Department of Biology, University of Oxford, Oxford, UK.
- Department of Biochemistry, University of Oxford, Oxford, UK.
| | - William P J Smith
- Department of Biology, University of Oxford, Oxford, UK.
- Department of Biochemistry, University of Oxford, Oxford, UK.
- Division of Genomics, Infection and Evolution, University of Manchester, Manchester, UK.
| | - Kevin R Foster
- Department of Biology, University of Oxford, Oxford, UK.
- Department of Biochemistry, University of Oxford, Oxford, UK.
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5
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Wells M, Schneider R, Bhattarai B, Currie H, Chavez B, Christopher G, Rumbaugh K, Gordon V. Perspective: The viscoelastic properties of biofilm infections and mechanical interactions with phagocytic immune cells. Front Cell Infect Microbiol 2023; 13:1102199. [PMID: 36875516 PMCID: PMC9978752 DOI: 10.3389/fcimb.2023.1102199] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 01/24/2023] [Indexed: 02/18/2023] Open
Abstract
Biofilms are viscoelastic materials that are a prominent public health problem and a cause of most chronic bacterial infections, in large part due to their resistance to clearance by the immune system. Viscoelastic materials combine both solid-like and fluid-like mechanics, and the viscoelastic properties of biofilms are an emergent property of the intercellular cohesion characterizing the biofilm state (planktonic bacteria do not have an equivalent property). However, how the mechanical properties of biofilms are related to the recalcitrant disease that they cause, specifically to their resistance to phagocytic clearance by the immune system, remains almost entirely unstudied. We believe this is an important gap that is ripe for a large range of investigations. Here we present an overview of what is known about biofilm infections and their interactions with the immune system, biofilm mechanics and their potential relationship with phagocytosis, and we give an illustrative example of one important biofilm-pathogen (Pseudomonas aeruginosa) which is the most-studied in this context. We hope to inspire investment and growth in this relatively-untapped field of research, which has the potential to reveal mechanical properties of biofilms as targets for therapeutics meant to enhance the efficacy of the immune system.
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Affiliation(s)
- Marilyn Wells
- Department of Physics, Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, TX, United States
| | - Rebecca Schneider
- Department of Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, United States
| | - Bikash Bhattarai
- Department of Mechanical Engineering, Texas Tech University, Lubbock, TX, United States
| | - Hailey Currie
- Department of Physics, Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, TX, United States
| | - Bella Chavez
- Department of Physics, Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, TX, United States
| | - Gordon Christopher
- Department of Mechanical Engineering, Texas Tech University, Lubbock, TX, United States
| | - Kendra Rumbaugh
- Department of Surgery, Texas Tech University Health Sciences Center, Lubbock, TX, United States
| | - Vernita Gordon
- Department of Physics, Center for Nonlinear Dynamics, The University of Texas at Austin, Austin, TX, United States
- LaMontagne Center for Infectious Disease, The University of Texas at Austin, Austin, TX, United States
- Interdisciplinary Life Sciences Graduate Program, The University of Texas at Austin, Austin, TX, United States
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6
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Razgaleh SA, Wrench A, Jones AAD. Surface Energy and Viscoelastic Characteristics of Staphylococcus epidermidis and Cutibacterium acnes Biofilm on Commercial Skin Constructs versus agar. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.10.527933. [PMID: 36798165 PMCID: PMC9934662 DOI: 10.1101/2023.02.10.527933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Biofilms are recalcitrant to both study and infectious disease treatment as it requires not only the study or management of single organism behavior, but also many dynamical interactions including but not limited to bacteria-bacteria, bacteria-host, bacteria-nutrients, and bacteria-material across multiple time scales. This study performs comparative and quantitative research of two materials used in biofilm research, TSA agar and skin epidermal, to reveal how adhesion effects viscoelastic properties of biofilms at long time scales. We show that the host surface stressors, such as wettability and surface energy, impact the biofilm's mechanical integrity and viscoelastic properties. While it is known that the bacteria-material interface influences initial biofilm formation and external stress influences mature biofilm function, this study examines the influence of the bacteria-material interface on mature biofilms. These mechanical viscoelastic properties have the potential to determine metabolite and pathogenesis pathways which means that the platform researchers use to study impacts the outcome.
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Affiliation(s)
- S A Razgaleh
- Department of Civil & Environmental Engineering, Pratt School of Engineering, Duke University
| | - Andrew Wrench
- Duke University Program in Environmental Health
- Department of Biomedical Engineering
| | - A-Andrew D Jones
- Department of Civil & Environmental Engineering, Pratt School of Engineering, Duke University
- Duke University Program in Environmental Health
- Thomas Lord Department of Mechanical Engineering & Materials Science, Duke University
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7
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Sarlet A, Ruffine V, Blank KG, Bidan CM. Influence of Metal Cations on the Viscoelastic Properties of Escherichia coli Biofilms. ACS OMEGA 2023; 8:4667-4676. [PMID: 36777596 PMCID: PMC9910073 DOI: 10.1021/acsomega.2c06438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 01/19/2023] [Indexed: 06/18/2023]
Abstract
Biofilms frequently cause complications in various areas of human life, e.g., in medicine and in the food industry. More recently, biofilms are discussed as new types of living materials with tunable mechanical properties. In particular, Escherichia coli produces a matrix composed of amyloid-forming curli and phosphoethanolamine-modified cellulose fibers in response to suboptimal environmental conditions. It is currently unknown how the interaction between these fibers contributes to the overall mechanical properties of the formed biofilms and if extrinsic control parameters can be utilized to manipulate these properties. Using shear rheology, we show that biofilms formed by the E. coli K-12 strain AR3110 stiffen by a factor of 2 when exposed to the trivalent metal cations Al(III) and Fe(III), while no such response is observed for the bivalent cations Zn(II) and Ca(II). Strains producing only one matrix component did not show any stiffening response to either cation or even a small softening. No stiffening response was further observed when strains producing only one type of fiber were co-cultured or simply mixed after biofilm growth. These results suggest that the E. coli biofilm matrix is a uniquely structured composite material when both matrix fibers are produced from the same bacterium. While the exact interaction mechanism between curli, phosphoethanolamine-modified cellulose, and trivalent metal cations is currently not known, our results highlight the potential of using extrinsic parameters to understand and control the interplay between biofilm structure and mechanical properties. This will ultimately aid in the development of better strategies for controlling biofilm growth.
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Affiliation(s)
- Adrien Sarlet
- Department
of Biomaterials, Max Planck Institute of
Colloids and Interfaces, Am Mühlenberg 1, 14476Potsdam, Germany
| | - Valentin Ruffine
- Mechano(bio)chemistry, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476Potsdam, Germany
| | - Kerstin G. Blank
- Mechano(bio)chemistry, Max Planck Institute of Colloids and Interfaces, Am Mühlenberg 1, 14476Potsdam, Germany
- Institute
of Experimental Physics, Johannes Kepler
University, Altenberger
Str. 69, 4040Linz, Austria
| | - Cécile M. Bidan
- Department
of Biomaterials, Max Planck Institute of
Colloids and Interfaces, Am Mühlenberg 1, 14476Potsdam, Germany
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8
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Huang C, Clark GG, Zaki FR, Won J, Ning R, Boppart SA, Elbanna AE, Nguyen TH. Effects of phosphate and silicate on stiffness and viscoelasticity of mature biofilms developed with simulated drinking water. BIOFOULING 2023; 39:36-46. [PMID: 36847486 PMCID: PMC10065970 DOI: 10.1080/08927014.2023.2177538] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 01/19/2023] [Accepted: 02/02/2023] [Indexed: 05/21/2023]
Abstract
Biofilms, a porous matrix of cells aggregated with extracellular polymeric substances under the influence of chemical constituents in the feed water, can develop a viscoelastic response to mechanical stresses. In this study, the roles of phosphate and silicate, common additives in corrosion control and meat processing, on the stiffness, viscoelasticity, porous structure networks, and chemical properties of biofilm were investigated. Three-year biofilms on PVC coupons were grown from sand-filtered groundwater with or without one of the non-nutrient (silicate) or nutrient additives (phosphate or phosphate blends). Compared with non-nutrient additives, the phosphate and phosphate-blend additives led to a biofilm with the lowest stiffness, most viscoelastic, and more porous structure, including more connecting throats with greater equivalent radii. The phosphate-based additives also led to more organic species in the biofilm matrix than the silicate additive did. This work demonstrated that nutrient additives could promote biomass accumulation but also reduce mechanical stability.
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Affiliation(s)
- Conghui Huang
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL
| | - Gemma G. Clark
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL
| | - Farzana R. Zaki
- Beckman Institute for Advanced Science and Technology, 405 North Mathews Avenue, Urbana, Illinois 61801, USA
| | - Jungeun Won
- Beckman Institute for Advanced Science and Technology, 405 North Mathews Avenue, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois Urbana Champaign, 1304 West Springfield Avenue, Urbana, Illinois 61801, USA
| | - Runsen Ning
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL
| | - Stephen A. Boppart
- Beckman Institute for Advanced Science and Technology, 405 North Mathews Avenue, Urbana, Illinois 61801, USA
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, 506 South Mathews Avenue, Urbana, Illinois 61801, USA
- Department of Bioengineering, University of Illinois Urbana Champaign, 1304 West Springfield Avenue, Urbana, Illinois 61801, USA
- Department of Electrical and Computer Engineering, University of Illinois Urbana Champaign, 306 North Wright Street, Urbana, Illinois 61801, USA
| | - Ahmed E. Elbanna
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL
| | - Thanh H. Nguyen
- Department of Civil and Environmental Engineering, University of Illinois at Urbana Champaign, Urbana, IL
- Institute of Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, Illinois, 61801, United States
- Carle Illinois College of Medicine, University of Illinois at Urbana-Champaign, 506 South Mathews Avenue, Urbana, Illinois 61801, USA
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Geisel S, Secchi E, Vermant J. Experimental challenges in determining the rheological properties of bacterial biofilms. Interface Focus 2022; 12:20220032. [PMID: 36330324 PMCID: PMC9560794 DOI: 10.1098/rsfs.2022.0032] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Accepted: 08/03/2022] [Indexed: 08/01/2023] Open
Abstract
Bacterial biofilms are communities living in a matrix consisting of self-produced, hydrated extracellular polymeric substances. Most microorganisms adopt the biofilm lifestyle since it protects by conferring resistance to antibiotics and physico-chemical stress factors. Consequently, mechanical removal is often necessary but rendered difficult by the biofilm's complex, viscoelastic response, and adhesive properties. Overall, the mechanical behaviour of biofilms also plays a role in the spreading, dispersal and subsequent colonization of new surfaces. Therefore, the characterization of the mechanical properties of biofilms plays a crucial role in controlling and combating biofilms in industrial and medical environments. We performed in situ shear rheological measurements of Bacillus subtilis biofilms grown between the plates of a rotational rheometer under well-controlled conditions relevant to many biofilm habitats. We investigated how the mechanical history preceding rheological measurements influenced biofilm mechanics and compared these results to the techniques commonly used in the literature. We also compare our results to measurements using interfacial rheology on bacterial pellicles formed at the air-water interface. This work aims to help understand how different growth and measurement conditions contribute to the large variability of mechanical properties reported in the literature and provide a new tool for the rigorous characterization of matrix components and biofilms.
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Affiliation(s)
- Steffen Geisel
- Laboratory for Soft Materials, Department of Materials, ETH Zurich, Zurich, Switzerland
| | - Eleonora Secchi
- Department of Civil, Environmental and Geomatic Engineering, ETH Zurich, Zurich, Switzerland
| | - Jan Vermant
- Laboratory for Soft Materials, Department of Materials, ETH Zurich, Zurich, Switzerland
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Obtention of New Edible Biofilms from Water Kefir Grains in Comparison with Conventional Biofilms from Taro (Colocasia esculenta) and Cassava (Manihot esculenta) Starch. Processes (Basel) 2022. [DOI: 10.3390/pr10091804] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Microorganism biomass is a sustainable and innovative source of biopolymers, such as proteins and polysaccharides, that is suitable for the development of biodegradable films. The aim of this research was to evaluate the synthesis, morphology, rheology, and morphological and mechanical properties on the production of edible biofilms based on water kefir grains, and compare them with edible films based on thermoplastic compounds from starch (TPS) obtained from taro (Colocasia esculenta) and cassava (Manihot esculenta). Edible biofilms were prepared in solution with 30% wt/wt glycerol relative to starch mass and kefir grain biofilms using the casting method. A stationary rheological analysis was performed on the film-forming suspensions of kefir, taro starch, and cassava starch. Once the films were obtained, a physicochemical and morphological characterization was carried out. Results of the characterization showed the following main aspects: The results indicated an increase in biomass production using muscovado and pineapple peel. The film-forming suspensions had a dilating behavior; however, the results obtained not only show the viscoelastic behavior but also the elastic limit (σ0), which varied from 0.077 to 0.059 Pa for suspensions of water kefir grains and from 0.077 to 0.072 Pa for starch suspensions. These elastic limit variations can be defined as the minimum shear stress required to start the flow, and all these rheological data were adjusted to the Herschel–Bulkley model; the morphological and mechanical characterization of the films obtained showed homogeneous surfaces with transparency and without cracks; regarding the water activity, values lower than 6 were obtained, which indicates that there will be no growth of any microorganism, and the hardness data showed differences between those obtained from kefir and taro and cassava starch. The similar results of the rheological characterization in the formation of the kefir biofilm and the conventional edible starch films, in addition to the similar results in the water activity below 6 and the hardness, points to an attractive alternative capable of replacing the conventional materials with a mass production of biofilms of probiotic microorganisms. The results also revealed that water kefir grains biomass is a viable and innovative source of biodegradable materials, and these grains can be an alternative to conventional established starch materials.
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11
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Megusar P, Stopar D, Poklar Ulrih N, Dogsa I, Prislan I. Thermal and Rheological Properties of Gluten-Free, Starch-Based Model Systems Modified by Hydrocolloids. Polymers (Basel) 2022; 14:3242. [PMID: 36015498 PMCID: PMC9415605 DOI: 10.3390/polym14163242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/22/2022] [Accepted: 07/26/2022] [Indexed: 12/05/2022] Open
Abstract
Obtaining good-quality gluten-free products represents a technological challenge; thus, it is important to understand how and why the addition of hydrocolloids influences the properties of starch-based products. To obtain insight into the physicochemical changes imparted by hydrocolloids on gluten-free dough, we prepared several suspensions with different corn starch/potato starch/hydroxpropyl methyl cellulose/xanthan gum/water ratios. Properties of the prepared samples were determined by differential scanning calorimetry and rheometry. Samples with different corn/potato starch ratios exhibited different thermal properties. Xanthan gum and HPMC (hydroxypropyl methyl cellulose) exhibited a strong influence on the rheological properties of the mixtures since they increased the viscosity and elasticity. HPMC and xanthan gum increased the temperature of starch gelatinization, as well as they increased the viscoelasticity of the starch model system. Although the two hydrocolloids affected the properties of starch mixtures in the same direction, the magnitude of their effects was different. Our results indicate that water availability, which plays a crucial role in the starch gelatinization process, could be modified by adding hydrocolloids such as, hydroxypropyl methyl cellulose and xanthan gum. By adding comparatively small amounts of the studied hydrocolloids to starch, one can achieve similar thermo-mechanical effects by the addition of gluten. Understanding these effects of hydrocolloids could contribute to the development of better quality gluten-free bread with optimized ingredient content.
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Affiliation(s)
- Polona Megusar
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - David Stopar
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Natasa Poklar Ulrih
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Iztok Dogsa
- Department of Microbiology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Iztok Prislan
- Department of Food Science and Technology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
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12
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Pandur Ž, Dular M, Kostanjšek R, Stopar D. Bacterial cell wall material properties determine E. coli resistance to sonolysis. ULTRASONICS SONOCHEMISTRY 2022; 83:105919. [PMID: 35077964 PMCID: PMC8789596 DOI: 10.1016/j.ultsonch.2022.105919] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/23/2021] [Accepted: 01/13/2022] [Indexed: 05/02/2023]
Abstract
The applications of bacterial sonolysis in industrial settings are plagued by the lack of the knowledge of the exact mechanism of action of sonication on bacterial cells, variable effectiveness of cavitation on bacteria, and inconsistent data of its efficiency. In this study we have systematically changed material properties of E. coli cells to probe the effect of different cell wall layers on bacterial resistance to ultrasonic irradiation (20 kHz, output power 6,73 W, horn type, 3 mm probe tip diameter, 1 ml sample volume). We have determined the rates of sonolysis decay for bacteria with compromised major capsular polymers, disrupted outer membrane, compromised peptidoglycan layer, spheroplasts, giant spheroplasts, and in bacteria with different cell physiology. The non-growing bacteria were 5-fold more resistant to sonolysis than growing bacteria. The most important bacterial cell wall structure that determined the outcome during sonication was peptidoglycan. If peptidoglycan was remodelled, weakened, or absent the cavitation was very efficient. Cells with removed peptidoglycan had sonolysis resistance equal to lipid vesicles and were extremely sensitive to sonolysis. The results suggest that bacterial physiological state as well as cell wall architecture are major determinants that influence the outcome of bacterial sonolysis.
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Affiliation(s)
- Žiga Pandur
- University of Ljubljana, Biotechnical Faculty, Večna pot 111, 1000 Ljubljana, SI-Slovenia; University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva 6, 1000 Ljubljana, SI-Slovenia
| | - Matevž Dular
- University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva 6, 1000 Ljubljana, SI-Slovenia
| | - Rok Kostanjšek
- University of Ljubljana, Biotechnical Faculty, Večna pot 111, 1000 Ljubljana, SI-Slovenia
| | - David Stopar
- University of Ljubljana, Biotechnical Faculty, Večna pot 111, 1000 Ljubljana, SI-Slovenia.
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Sande C, Whitfield C. Capsules and Extracellular Polysaccharides in Escherichia coli and Salmonella. EcoSal Plus 2021; 9:eESP00332020. [PMID: 34910576 PMCID: PMC11163842 DOI: 10.1128/ecosalplus.esp-0033-2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2021] [Accepted: 10/26/2021] [Indexed: 12/16/2022]
Abstract
Escherichia coli and Salmonella isolates produce a range of different polysaccharide structures that play important roles in their biology. E. coli isolates often possess capsular polysaccharides (K antigens), which form a surface structural layer. These possess a wide range of repeat-unit structures. In contrast, only one capsular polymer (Vi antigen) is found in Salmonella, and it is confined to typhoidal serovars. In both genera, capsules are vital virulence determinants and are associated with the avoidance of host immune defenses. Some isolates of these species also produce a largely secreted exopolysaccharide called colanic acid as part of their complex Rcs-regulated phenotypes, but the precise function of this polysaccharide in microbial cell biology is not fully understood. E. coli isolates produce two additional secreted polysaccharides, bacterial cellulose and poly-N-acetylglucosamine, which play important roles in biofilm formation. Cellulose is also produced by Salmonella isolates, but the genes for poly-N-acetylglucosamine synthesis appear to have been lost during its evolution toward enhanced virulence. Here, we discuss the structures, functions, relationships, and sophisticated assembly mechanisms for these important biopolymers.
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Affiliation(s)
- Caitlin Sande
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Chris Whitfield
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
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Balasubramanian S, Yu K, Cardenas DV, Aubin-Tam ME, Meyer AS. Emergent Biological Endurance Depends on Extracellular Matrix Composition of Three-Dimensionally Printed Escherichia coli Biofilms. ACS Synth Biol 2021; 10:2997-3008. [PMID: 34652130 PMCID: PMC8609572 DOI: 10.1021/acssynbio.1c00290] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
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Biofilms are three-dimensional
(3D) bacterial communities that
exhibit a highly self-organized nature in terms of their composition
and complex architecture. Bacteria in biofilms display emergent biological
properties, such as resistance to antimicrobials and disinfectants
that the individual planktonic cells lack. Bacterial biofilms possess
specialized architectural features including unique extracellular
matrix compositions and a distinct spatially patterned arrangement
of cells and matrix components within the biofilm. It is unclear which
of these architectural elements of bacterial biofilms lead to the
development of their emergent biological properties. Here, we report
a 3D printing-based technique for studying the emergent resistance
behaviors of Escherichia coli biofilms
as a function of their architecture. Cellulose and curli are the major
extracellular-matrix components in E. coli biofilms. We show that 3D-printed biofilms expressing either curli
alone or both curli and cellulose in their extracellular matrices
show higher resistance to exposure against disinfectants than 3D prints
expressing either cellulose alone or no biofilm-matrix components.
The 3D-printed biofilms expressing cellulose and/or curli also show
thicker anaerobic zones than nonbiofilm-forming E.
coli 3D prints. Thus, the matrix composition plays
a crucial role in the emergent spatial patterning and biological endurance
of 3D-printed biofilms. In contrast, initial spatial distribution
of bacterial density or curli-producing cells does not have an effect
on biofilm resistance phenotypes. Further, these 3D-printed biofilms
could be reversibly attached to different surfaces (bacterial cellulose,
glass, and polystyrene) and display resistance to physical distortions
by retaining their shape and structure. This physical robustness highlights
their potential in applications including bioremediation, protective
coatings against pathogens on medical devices, or wastewater treatment,
among many others. This new understanding of the emergent behavior
of bacterial biofilms could aid in the development of novel engineered
living materials using synthetic biology and materials science approaches.
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Affiliation(s)
- Srikkanth Balasubramanian
- Department of Sustainable Design Engineering, Faculty of Industrial Design Engineering, Delft University of Technology, 2628 CE Delft, The Netherlands
| | - Kui Yu
- Department of Bionanoscience & Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Diana Vasquez Cardenas
- Department of Biotechnology, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Marie-Eve Aubin-Tam
- Department of Bionanoscience & Kavli Institute of Nanoscience, Delft University of Technology, 2629 HZ Delft, The Netherlands
| | - Anne S. Meyer
- Department of Biology, University of Rochester, Rochester, New York 14627, United States
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Kitamura H, Omori T, Ishikawa T. Impact of rheological properties on bacterial streamer formation. J R Soc Interface 2021; 18:20210546. [PMID: 34665976 PMCID: PMC8526168 DOI: 10.1098/rsif.2021.0546] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Bacterial biofilms, which can be found wherever there is water and a substrate, can cause chronic infections and clogging of industrial flow systems. Despite intensive investigation of the dynamics and rheological properties of biofilms, the impact of their rheological properties on streamer growth remains unknown. We numerically simulated biofilm growth in a pillar-flow and investigated the effects of rheological properties of a filamentous flow-shaped biofilm, called a 'streamer', on its formation by varying the viscoelasticity. The flow-field is assumed to be a Stokes flow and is solved by a boundary element method. A Maxwell model is used for extracellular matrix-mediated streamer growth to express the fluidity of streamer formations. Both high elastic modulus and viscosity are needed for streamer formation, and high viscosity promotes streamer growth at low cell concentrations. Our findings are consistent with experimental observations and can explain the relationship between the cell concentrations and viscosity at which streamers form.
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Affiliation(s)
- Hiroki Kitamura
- Department of Finemechanics, Tohoku University, Aoba 6-6-01, Sendai, Miyagi, Japan
| | - Toshihiro Omori
- Department of Finemechanics, Tohoku University, Aoba 6-6-01, Sendai, Miyagi, Japan
| | - Takuji Ishikawa
- Department of Finemechanics, Tohoku University, Aoba 6-6-01, Sendai, Miyagi, Japan.,Department of Biomedical Engineering, Tohoku University, Aoba 6-6-01, Sendai, Miyagi, Japan
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16
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In Vitro Study of the Synergistic Effect of an Enzyme Cocktail and Antibiotics against Biofilms in a Prosthetic Joint Infection Model. Antimicrob Agents Chemother 2021; 65:AAC.01699-20. [PMID: 33468484 DOI: 10.1128/aac.01699-20] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 12/29/2020] [Indexed: 11/20/2022] Open
Abstract
Prosthetic joint infections (PJI) are frequent complications of arthroplasties. Their treatment is made complex by the rapid formation of bacterial biofilms, limiting the effectiveness of antibiotic therapy. In this study, we explore the effect of a tri-enzymatic cocktail (TEC) consisting of an endo-1,4-β-d-glucanase, a β-1,6-hexosaminidase, and an RNA/DNA nonspecific endonuclease combined with antibiotics of different classes against biofilms of Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli grown on Ti-6Al-4V substrates. Biofilms were grown in Trypticase soy broth (TSB) with 10 g/liter glucose and 20 g/liter NaCl (TGN). Mature biofilms were assigned to a control group or treated with the TEC for 30 min and then either analyzed or reincubated for 24 h in TGN or TGN with antibiotics. The cytotoxicity of the TEC was assayed against MG-63 osteoblasts, primary murine fibroblasts, and J-774 macrophages using the lactate dehydrogenase (LDH) release test. The TEC dispersed 80.3 to 95.2% of the biofilms' biomass after 30 min. The reincubation of the treated biofilms with antibiotics resulted in a synergistic reduction of the total culturable bacterial count (CFU) compared to that of biofilms treated with antibiotics alone in the three tested species (additional reduction from 2 to more than 3 log10 CFU). No toxicity of the TEC was observed against the tested cell lines after 24 h of incubation. The combination of pretreatment with TEC followed by 24 h of incubation with antibiotics had a synergistic effect against biofilms of S. aureus, S. epidermidis, and E. coli Further studies should assess the potential of the TEC as an adjuvant therapy in in vivo models of PJI.
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Tailorable hydrogel of gelatin with silk fibroin and its activation/crosslinking for enhanced proliferation of fibroblast cells. Int J Biol Macromol 2020; 164:4073-4083. [DOI: 10.1016/j.ijbiomac.2020.09.016] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 09/01/2020] [Accepted: 09/02/2020] [Indexed: 02/07/2023]
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18
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Jeffries J, Thongsomboon W, Visser JA, Enriquez K, Yager D, Cegelski L. Variation in the ratio of curli and phosphoethanolamine cellulose associated with biofilm architecture and properties. Biopolymers 2020; 112:e23395. [PMID: 32894594 DOI: 10.1002/bip.23395] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 07/17/2020] [Accepted: 07/20/2020] [Indexed: 11/11/2022]
Abstract
Bacterial biofilms are communities of bacteria entangled in a self-produced extracellular matrix (ECM). Escherichia coli direct the assembly of two insoluble biopolymers, curli amyloid fibers, and phosphoethanolamine (pEtN) cellulose, to build remarkable biofilm architectures. Intense curiosity surrounds how bacteria harness these amyloid-polysaccharide composites to build biofilms, and how these biopolymers function to benefit bacterial communities. Defining ECM composition involving insoluble polymeric assemblies poses unique challenges to analysis and, thus, to comparing strains with quantitative ECM molecular correlates. In this work, we present results from a sum-of-the-parts 13 C solid-state nuclear magnetic resonance (NMR) analysis to define the curli-to-pEtN cellulose ratio in the isolated ECM of the E. coli laboratory K12 strain, AR3110. We compare and contrast the compositional analysis and comprehensive biofilm phenotypes for AR3110 and a well-studied clinical isolate, UTI89. The ECM isolated from AR3110 contains approximately twice the amount of pEtN cellulose relative to curli content as UTI89, revealing plasticity in matrix assembly principles among strains. The two parent strains and a panel of relevant gene mutants were investigated in three biofilm models, examining: (a) macrocolonies on agar, (b) pellicles at the liquid-air interface, and (c) biomass accumulation on plastic. We describe the influence of curli, cellulose, and the pEtN modification on biofilm phenotypes with power in the direct comparison of these strains. The results suggest that curli more strongly influence adhesion, while pEtN cellulose drives cohesion. Their individual and combined influence depends on both the biofilm modality (agar, pellicle, or plastic-associated) and the strain itself.
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Affiliation(s)
- Jamie Jeffries
- Department of Molecular and Cellular Physiology, School of Medicine, Stanford University, Stanford, California, USA
| | | | | | - Kyle Enriquez
- Department of Chemistry, Stanford University, Stanford, California, USA
| | - Deborah Yager
- Department of Chemistry, Stanford University, Stanford, California, USA
| | - Lynette Cegelski
- Department of Chemistry, Stanford University, Stanford, California, USA
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Simunič U, Pipp P, Dular M, Stopar D. The limitations of hydrodynamic removal of biofilms from the dead-ends in a model drinking water distribution system. WATER RESEARCH 2020; 178:115838. [PMID: 32361344 DOI: 10.1016/j.watres.2020.115838] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/07/2020] [Accepted: 04/14/2020] [Indexed: 06/11/2023]
Abstract
Biofilm formation and removal from dead-ends is a particularly difficult and understudied area of water distribution system biology. In this work, we have built a model drinking water distribution system to probe the effect of different hydrodynamic flow regimes on biofilm formation and removal in the main pipe and in the dead-end. The test rig was built to include all major drinking water distribution system components with materials and dimensions used in standard plumbing systems. We have simulated the effect of stagnant, laminar, turbulent, and intense turbulent flushing conditions on the growth and removal of biofilms from the main pipe and the dead-end. The growth of the biofilm in the main pipe was not prevented at a volumetric flow rate of 9.4 L min-1 and flow velocity of 2 m s-1. Mature biofilms were more difficult to remove. Biofilms grown under shear stress conditions could withstand significantly higher shear stresses than those to which they were exposed to during growth. The biofilms grew twice as fast in the dead-end when flow in the main pipe was turbulent compared to stagnant conditions. Biofilms in the dead-end were not affected by the flushing conditions in the main pipe (Q = 52 L min-1, Re = 9.0 · 104). The computational fluid dynamics simulation suggests that biofilms cannot be hydrodynamically removed from the dead-end at depths that are larger than one pipe diameter. Biofilms beyond this limit present a possible source for reinoculation and recolonization of the rest of the water distribution system.
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Affiliation(s)
- Urh Simunič
- University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, 1000, Ljubljana, Slovenia
| | - Peter Pipp
- University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva 6, 1000, Ljubljana, Slovenia
| | - Matevž Dular
- University of Ljubljana, Faculty of Mechanical Engineering, Aškerčeva 6, 1000, Ljubljana, Slovenia
| | - David Stopar
- University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, 1000, Ljubljana, Slovenia.
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