Modulation of Biofilm Growth by Shear and Fluctuations in Turbulent Environments

Modulation of Biofilm Growth by Shear and Fluctuations in Turbulent Environments | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Modulation of Biofilm Growth by Shear and Fluctuations in Turbulent Environments Federico Pizzi, Francesc Peters, Elena Sorribes, Isabel Marín-Beltrán, and 5 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5826333/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 11 Apr, 2025 Read the published version in Scientific Reports → Version 1 posted 10 You are reading this latest preprint version Abstract This work investigates the role of shear and turbulent fluctuations on multi-species biofilm growth. The study is mostly motivated by understanding biofouling on microplastics (MPs) in oceanic environments. By increasing particle stickiness, biofilms promote MP aggregation and sinking; therefore, a thorough understanding of this multi-scale process is crucial to improve predictions of the MPs fate. We conducted a series of laboratory experiments using an oscillating-grid system to promote biofilm growth on small plastic surfaces under homogeneous isotropic turbulence with grid Reynolds numbers between 305 and 2220. Two configurations were analyzed: one where plastic samples move along with the grid (shear-dominated) and another one where the samples are kept fixed downstream the grid, thus experiencing turbulence but no mean flow (shear-free). Biofilm formed in all cases in a time scale of days, then the biomass formed on the plastic pieces was carefully measured and analyzed as a function of the turbulence level. The shear-free results were further interpreted using a parsimonious physical model, coupling the nutrient uptake rate within the biofilm (Monod kinetics) with the turbulent diffusion of the surrounding bulk liquid. Results show that: (i) under shear-dominated conditions, the biofilm mass initially grows with turbulence intensity before decaying, presumably due to shear-induced erosion; (ii) in the shear-free experiments, the mass increases monotonically following an enhanced availability of nutrients, and then saturates due to uptake-limited kinetics. This latter behavior is well reproduced by the physical model.Furthermore, a subset of plastic pieces were analyzed with a scanning electron microscope, revealing that turbulence also affects the microscopic configuration of biofilm clusters, increasing their compactness as the amplitude of turbulent fluctuations increases. These results contribute not only to our fundamental understanding of biofilms under flow, but can also inform global models of MP transport in marine environments. Physical sciences/Engineering/Mechanical engineering Earth and environmental sciences/Ocean sciences/Marine biology Full Text Additional Declarations No competing interests reported. Supplementary Files supplementaryinformation.pdf Cite Share Download PDF Status: Published Journal Publication published 11 Apr, 2025 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Revision requested 06 Feb, 2025 Reviews received at journal 01 Feb, 2025 Reviews received at journal 25 Jan, 2025 Reviewers agreed at journal 21 Jan, 2025 Reviewers agreed at journal 20 Jan, 2025 Reviewers invited by journal 20 Jan, 2025 Editor assigned by journal 20 Jan, 2025 Editor invited by journal 20 Jan, 2025 Submission checks completed at journal 17 Jan, 2025 First submitted to journal 14 Jan, 2025 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5826333","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":403499837,"identity":"96c2e943-24fb-4f47-a97c-10a3292a6e05","order_by":0,"name":"Federico Pizzi","email":"","orcid":"","institution":"Universitat Politècnica de Catalunya","correspondingAuthor":false,"prefix":"","firstName":"Federico","middleName":"","lastName":"Pizzi","suffix":""},{"id":403499838,"identity":"6838d31c-c794-4c84-9a57-bc128ed32534","order_by":1,"name":"Francesc Peters","email":"","orcid":"","institution":"Institut de Ciències del Mar - CSIC","correspondingAuthor":false,"prefix":"","firstName":"Francesc","middleName":"","lastName":"Peters","suffix":""},{"id":403499839,"identity":"47204cc3-816e-47f8-b74e-ed0bc665b713","order_by":2,"name":"Elena Sorribes","email":"","orcid":"","institution":"University of Barcelona","correspondingAuthor":false,"prefix":"","firstName":"Elena","middleName":"","lastName":"Sorribes","suffix":""},{"id":403499841,"identity":"e8db1d50-5466-44de-ad6b-c3952beaa862","order_by":3,"name":"Isabel Marín-Beltrán","email":"","orcid":"","institution":"Centro de Ciências do Mar do Algarve","correspondingAuthor":false,"prefix":"","firstName":"Isabel","middleName":"","lastName":"Marín-Beltrán","suffix":""},{"id":403499843,"identity":"b1d51ef8-d41f-4c7a-b6aa-a9463e787df6","order_by":4,"name":"Cristina Romera-Castillo","email":"","orcid":"","institution":"Institut de Ciències del Mar - 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