Year: 2025
Type: article
Abstract: Structural coloration in biological systems arises from the interaction of light with micro‐ and nanoscale structures, producing vivid, pigment‐free optical effects. While this phenomenon is well‐documented in butterflies and birds, recent reports have revealed that certain microorganisms, particularly those in the Bacteroidetes phylum, also exhibit striking structural coloration when formed into biofilms. In the marine bacterium Cellulophaga lytica ( C. lytica ), iridescence emerges dynamically during biofilm development and is tightly coupled to gliding motility, a surface‐associated mechanism of locomotion. However, the influence of environmental mechanics on this self‐organizing photonic behavior remains poorly understood. This investegation demonstrates how substrate properties, specifically agar stiffness and salt‐modulated stress relaxation, regulate the gliding motility and emergent iridescence of C. lytica biofilms. Time‐lapse imaging, quantitative optical analysis, and bulk rheological measurements demonstrate that increasing agar stiffness enhances early‐stage collective motility and promotes the formation of green‐iridescent biofilms. Furthermore, salt concentration modulates the viscoelastic properties of the substrate, impacting both motility dynamics and the spatial evolution of structural color. Correlating substrate stiffness and development time with observed dominant iridescent hue enables the construction of a phase map revealing distinct regimes of photonic behavior, thus providing a framework for designing biologically‐inspired living optical systems with customizable structural colour.
Source: Advanced Functional Materials
Authors: Annie Scutte, Jaideep Katuri, Samuel Omeke, Nellymar Rivera‐Santiago, Cianna Williams, Claretta Sullivan, Jamel Ali
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Funders: National Science Foundation, National Aeronautics and Space Administration, National High Magnetic Field Laboratory, Florida Agricultural and Mechanical University, Nuclear Safety and Security Commission, Office of STEM Engagement, Division of Materials Research, Division of Civil, Mechanical and Manufacturing Innovation, Core Research for Evolutional Science and Technology, High Magnetic Field Laboratory, Chinese Academy of Sciences, Air Force Office of Scientific Research
Awards: G1019936685, CREST Phase II Center for Complex Materials Design, G1501637887, Targeted Infusion Project: Enhancing Retention in the Chemical & Biomedical Engineering Program at Florida A and M University through Integrated Research, Teaching and Retention, Research Initiation Award: Multifunctional Intracellular Nano-Probes based on Engineered Bacterial Flagella, G328819310, G4329687174, G5205423489, Excellence in Research: Biofilm Adhesive and Kinetic Properties Under Hydrodynamic Influences During Early Evolution Stages, G5613623313, National High Magnetic Field Laboratory Renewal 2023-2027, G742574937, G8152425740
OpenAlex ID: W4416226943