This readme.txt file was generated on <20251024> by Recommended citation for the data: Wei, Guanju; Yang, Judy. (2025). Data supporting “Biofilm Formation Promotes Microplastic Mobility via Hydrodynamic Forces”. Retrieved from the Data Repository for the University of Minnesota, https://XXX. ------------------- GENERAL INFORMATION ------------------- 1. Title of Dataset Data supporting “Biofilm Formation Promotes Microplastic Mobility via Hydrodynamic Forces” 2. Author Information Principal Investigator Contact Information Name: Guanju Wei Institution: Saint Anthony Falls Laboratory, University of Minnesota Address: 2 3rd Ave SE, Minneapolis, MN 55414 Email: wei00235@umn.edu ORCID: 0000-0001-5511-9242 Associate or Co-investigator Contact Information Name: Judy Yang Institution: Saint Anthony Falls Laboratory, University of Minnesota Address: 2 3rd Ave SE, Minneapolis, MN 55414 Email: judyyang@umn.edu ORCID: 0000-0001-6272-1266 3. Date published or finalized for release: 2025/10/24 4. Date of data collection (single date, range, approximate date) 2025/05/02 – 2025/07/24 5. Geographic location of data collection (where was data collected?): Saint Anthony Falls Laboratory, University of Minnesota 6. Information about funding sources that supported the collection of the data: This study was supported by National Science Foundation CAREER Award EAR 2236497. Portions of this work were conducted in the Minnesota Nano Center, which is supported by the National Science Foundation through the National Nanotechnology Coordinated Infrastructure (NNCI) under Award Number ECCS-2025124. 7. Overview of the data (abstract): This dataset supports the manuscript “Biofilm Formation Promotes Microplastic Mobility via Hydrodynamic Forces.” It includes measurements of biofilm area and the percentage of transported beads under five different flow rates, as well as an example set of microscopy images and a MATLAB dataset used for image processing. In the manuscript, we demonstrate that the presence of biofilms alters the hydrodynamic forces acting on microplastic particles. Specifically, biofilms modify the local pressure field and generate lift forces strong enough to mobilize particles even under weak shear conditions. -------------------------- SHARING/ACCESS INFORMATION -------------------------- 1. Licenses/restrictions placed on the data: CC0 1.0 Universal 2. Links to publications that cite or use the data: Manuscript under review. 3. Was data derived from another source? No. 4. Terms of Use: Data Repository for the U of Minnesota (DRUM) By using these files, users agree to the Terms of Use. https://conservancy.umn.edu/pages/policies/#drum-terms-of-use Yes. --------------------- DATA & FILE OVERVIEW --------------------- 1. File List A. Filename: Biofilm_Beads_Data.xlsx Short description: This spreadsheet contains measurements of biofilm area and the percentage of transported beads under five different flow rates. B. Filename: Image_Processing_Matlab Code.txt Short description: This spreadsheet contains measurements of biofilm area and the percentage of transported beads under five different flow rates. C. Filename: 5ulmin_image_example (folder) Short description: This folder contains a time-sequence image set for the 5 µL/min flow-rate case, provided as an example. 2. Relationship between files: The microscopy images were captured using a confocal microscope. The MATLAB code was used to process these images to quantify the biofilm area and identify transported beads. All resulting measurements are compiled and summarized in the spreadsheet. -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: Microfluidic experiments were conducted to investigate the interactions of microplastic beads and biofilms under controlled flow conditions. The system consists of a microfluidic chip, a Confocal Laser Scanning Microscope (Nikon C2 plus), and a programmable syringe pump (PHD Ultra, Harvard Apparatus). Soft lithography was used to fabricate polydimethylsiloxane (PDMS) microfluidic chips with the assistance of the University of Minnesota Nano Center. The straight channels utilized in this study have a height of 60 μm and a width of 400 μm. The channel measures ~5 mm in length from inlet to outlet. All the experiments were conducted under room temperature (~22°C). Confocal microscopy was used to image the biofilms in the microfluidic channel with 0.31 μm/pixel resolution. Biofilm-microplastic experiments were conducted following the steps described below. First, 2 mL of the nutrient solution (Luria Broth solution) was injected into the microfluidics to displace the air in the channel. Polyethylene (PE) microplastic beads were then manually introduced into the microchannel. Because the density of PE is slightly higher than that of water, the beads settled to the bottom by gravity. After allowing 30 min for stabilization, Pseudomonas aeruginosa (OD₆₀₀ = 0.5) suspensions were continuously injected at different flow rates (1, 2.5, 5, 7.5 and 10 µL/min) for 24 hours. During the experiments, we recorded biofilm development over time using a Nikon C2+ Confocal Laser Scanning Microscope with 0.3 μm horizontal resolution at the middle depth of the microplastic beads. The wavelength of the laser was 488 nm. The objective magnification was 20×. During the experiments, the images were scanned at 30 minute intervals and saved on an HP-Z4-G4 workstation. 2. Methods for processing the data: Biofilm coverage was quantified by summing the fluorescence intensity from confocal microscopy images. The number of microplastic beads was determined using custom scripts in MATLAB. Three-dimensional biofilm reconstructions were generated using BiofilmQ. All MATLAB codes used for image processing and quantification are available in the shared data repository. 3. Instrument- or software-specific information needed to interpret the data: Matlab, Excel 4. Standards and calibration information, if appropriate: / 5. Environmental/experimental conditions: All the experiments were conducted under room temperature (~22°C). 6. Describe any quality-assurance procedures performed on the data: All experiments were performed in triplicate. 7. People involved with sample collection, processing, analysis and/or submission: Guanju Wei (sample collection, processing, analysis, submission) Judy Yang (analysis, submission) ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: [Biofilm_Beads_Data.xlsx] ----------------------------------------- 1. Number of variables: 3 2. Number of cases/rows: ~70 rows, each row represent a time point. 3. Missing data codes: / 4. Variable List A. Name: < Time_hours > Description: Time point of image acquisition, expressed in hours. B. Name: < PercentTransported > Description: Percentage of beads that were transported at each time point. C. Name: < AvgAreaPerBead_um2 > Description: Average biofilm-covered area per bead, measured in square micrometers (µm²).