Biofouling最新文献

Plumbagin, also known as 5-hydroxy-2-methyl-1,4-naphthoquinone (PLB), is a naturally occurring naphthoquinone molecule that has demonstrated strong antibacterial and antibiofilm properties against Staphylococcus aureus (S. aureus). However, the potential of PLB to eradicate mature biofilms and the underlying mechanisms involved remain unclear. In this study explored the effects of PLB on disrupting mature S. aureus biofilms, focusing on its impact on the extracellular polymeric substances (EPS) and potential mechanisms of action. Crystal violet (CV) and XTT assays demonstrated that PLB significantly reduced both the biomass and metabolic activity of mature S. aureus biofilms in a concentration-dependent manner. High-content screening (HCS) imaging demonstrated that PLB treatment induced significant alterations in the biofilm EPS architecture, leading to a substantial reduction in overall biomass and average thickness, with disruption severity correlating positively with PLB concentration. Using molecular fluorescence probing techniques, this study found that treatment with PLB resulted in a marked reduction in EPS components, including extracellular polysaccharides (PIA), proteins, and extracellular DNA (eDNA), compared to untreated controls. Molecular docking analysis revealed that PLB strongly interacts with several key S. aureus proteins involved in EPS production, such as IcaA, IcaD, IcaB, IcaC, Bap, ClfB, and CidA, particularly binding strongly to the active sites of IcaA and Bap. Furthermore, gene expression analysis indicated that PLB downregulated genes associated with biofilm EPS production. Overall, these findings suggest that PLB effectively disrupts S. aureus biofilms by targeting the EPS. These results highlight PLB as a promising candidate for targeting mature S. aureus biofilms in chronic infections.

The rise of multidrug-resistant bacterial biofilms presents a significant challenge in biomedical applications, demanding innovative and eco-friendly solutions. In this study, bactericidal nanolayers (NLs) were engineered on titanium (Ti) surfaces using two isomeric phytocompounds: carvacrol (Carv-Ti-NL) and thymol (TOH-Ti-NL). These NLs were fabricated via a simple, one-step self-assembly process. Both exhibited strong anti-biofilm and bactericidal activity against Staphylococcus aureus. TOH-Ti-NL proved superior for osteogenesis, while fibroblasts showed reduced adhesion on TOH-Ti-NL but enhanced proliferation on Carv-Ti-NL. Attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR) spectroscopy confirmed spontaneous oxidation of Carv and TOH on Ti into ketonic structures. TOH-Ti-NL also displayed higher surface roughness, linked to improved osseointegration, and a higher release rate than Carv-Ti-NL. Both coatings eradicated bacteria within 24 h. Their early effectiveness underscores their potential for infection prevention on Ti implants. Thus, TOH-Ti-NL shows promise for bone-related applications, whereas Carv-Ti-NL may be better suited for fibroblast growth, offering tailored properties for diverse biomedical applications.

Antibiofouling membranes have become pivotal in addressing fouling challenges in membrane-based processes across water treatment, desalination and industrial applications. This review presents a comprehensive bibliometric analysis of global research trends, challenges, impacts and future opportunities in antibiofouling membranes. Utilising Bibliometrix in R and advanced visualisation techniques, 172 publications from 2006 to 2023 were analysed, with data extracted from Scopus and Web of Science databases accessed on December 5, 2024. Key bibliometric indicators, including total citations, co-authorship networks and keyword co-occurrences, were explored to map the scientific landscape. The findings reveal a steady growth in research, with the most cited publication achieving 452 citations and an average of 45.2 citations per year. Surface modification emerged as the dominant theme, occurring 60 times and achieving the highest betweenness centrality of 1,252.975, highlighting its role in improving antifouling and biofilm resistance. Other critical research areas include nanofiltration, reverse-osmosis membranes and the integration of advanced materials like graphene oxide, silver nanoparticles and polydopamine. Interdisciplinary collaborations among material science, chemistry and environmental engineering were identified as key drivers of innovation. Despite advancements, gaps persist in scaling up technologies, addressing environmental sustainability, and applying antibiofouling membranes in underexplored areas like seawater desalination and wastewater treatment. Emerging trends, including energy-efficient solutions, biofilm mitigation and computational modelling for predictive performance, present significant opportunities for future research. This review underscores the transformative potential of antibiofouling membranes in enhancing operational efficiency and sustainability. By addressing identified research gaps and fostering interdisciplinary approaches, this study provides actionable insights and a strategic roadmap for researchers and policymakers to advance antibiofouling membrane technologies to meet global water and environmental challenges.

Biofouling, the accumulation of marine organisms on submerged surfaces, presents growing challenges for maritime operations and coastal community resilience. This systematic review (2014 to 2024) synthesises recent findings on antifouling strategies, their environmental impacts, and implications for water security. Despite the global ban on tributyltin, many copper-based and organic biocides remain in use, contributing to sediment pollution and potential contamination of coastal aquifers. Biofouling also reduces the efficiency of desalination and water infrastructure, increasing costs and straining freshwater access in vulnerable regions. Saltwater intrusion, intensified by sea-level rise and groundwater overuse, further threatens groundwater quality. While green antifouling technologies show promise, adoption is limited in resource-constrained areas. Using the PRISMA framework, this study synthesises global findings, emphasising the need for sustainable antifouling solutions that balance pollution control, ship efficiency, and water security. Future research should integrate biofouling management with coastal water protection to enhance community resilience.

The emergence of multidrug-resistant pathogens linked to mixed biofilm infections is a significant concern due to limited therapeutic options. This health risk has renewed interest in developing new antibiofilm alternatives. In this study, the antibiofilm potential of a phosphonium-based ionic liquid against a mixed-species biofilm of Candida albicans and methicillin-resistant Staphylococcus haemolyticus (MRSH) was assessed preliminarily using the microbroth dilution assay. The ionic liquid inhibitory profiles were further explored by confocal Raman mapping, scanning electron microscopy (SEM), and fluorescence microscopy (FM). A substantial antibiofilm effect was demonstrated. Raman mapping showed a modified biofilm distribution following ionic liquid treatment, demonstrating the differential inhibitory effects between strains in mixed biofilm. Additionally, FM revealed that the morphological switching of Candida albicans was inhibited, while SEM revealed a disruption of biofilm integrity. On the other hand, the hemolysis test showed the safety profile of the ionic liquid by exhibiting low cytotoxicity at active concentrations.

Plate heat exchangers (PHEs) are widely used in chemical plants for cooling, and their performance typically deteriorates due to fouling formation. To address the operational lifetime of PHEs under fouling conditions and determine optimal repair time, a virtual framework is required to function as a digital twin. This study investigates the application of a vinyl acetate copolymer nano-coating on PHEs to reduce the fouling thickness of CaCO₃ using a Multiphysics simulation approach. The novelty of this work lies in the development of a numerical framework capable of accurately forecasting optimal repair times before the system's efficiency declines. The results reveal that nanocoating reduces the thermal resistance and the fouling thickness by 65.77% and 58.8%, respectively, compared to the uncoated sample. The proposed framework accurately determines the thermodynamic behaviour of the PHE as a digital twin and predicts the appropriate time for its repair or replacement.

The fixative most commonly used in biofilm measurement studies of pathogenic yeasts is ethanol. However, due to lipid dissolution in ethanol, this method may not be the optimal choice for certain yeasts which have a high lipid content in their cell walls, such as human pathogen Malassezia furfur. We conducted a study to compare the measurement values of 26 clinical strains of Malassezia furfur using glutaraldehyde and paraformaldehyde instead of ethanol. After the fixation step, standard staining methods were applied for biomass and extracellular polymers. Imaging was performed using scanning electron microscopy and optical coherence tomography. An important result for both biomass and extracellular polymers measurements, was that ethanol fixation group values were lower than other fixation methods (p < 0.001). The morphological formations, which were observed as small cohesive groups with ethanol fixation, were seen as adhesive groups with glutaraldehyde fixation. The application of glutaraldehyde in the fixation of biofilms produced by M. furfur yielded a greater range of absorbances, thus facilitating more comprehensive data evaluation than that achieved with ethanol. In yeasts such as Malassezia with a high lipid content in their cell wall, fixation with glutaraldehyde seems likely to contribute to easier analysis of comparative data in biofilm studies.

Biofouling poses significant ecological and operational challenges in marine environments, particularly across Indonesia's diverse tropical waters. It increases hydrodynamic drag on vessels, leading to greater fuel consumption and elevated operational costs. This review synthesizes both recent and historical studies to examine the taxonomic and functional diversity of marine biofouling organisms in Indonesian waters. It highlights key fouling groups - bacteria, diatoms, barnacles, bivalves, polychaetes, tunicates, hydrozoans, bryozoans, macroalgae, and sponges - and describes their roles in biofilm formation, macro fouler settlement, and successional development. The paper also explores spatial differences between western and eastern regions, outlining how environmental and human-driven factors influence colonization and community dynamics. Successional trends from early biofilms to climax stages are discussed in relation to marine infrastructure management and antifouling strategies. By integrating findings across the archipelago, this review provides foundational insight for region-specific mitigation efforts and supports the development of sustainable maritime operations in tropical coastal ecosystems.

This study investigated the antimicrobial and antibiotic-potentiating activities of two novel ruthenium complexes against clinically relevant bacterial strains. The complexes cis-[RuCl₂(dppb)(NN-F)] and cis-[RuCl₂(dppb)(NN-Br)] exhibited activity against Staphylococcus aureus and Staphylococcus epidermidis, with minimum inhibitory concentrations (MICs) ranging from 7.8 to 62.5 µg·ml^-1 and minimum bactericidal concentrations (MBCs) from 31.25 to 125 µg·ml^-1. When combined with ampicillin, both complexes demonstrated synergistic effects. Time-kill assays showed bactericidal activity within the first 2 to 12 h. The complexes significantly reduced biofilm biomass, viable cell counts and metabolic activity in both biofilm formation and mature biofilms. Microscopy revealed membrane damage and increased generation of reactive oxygen species (ROS) in S. aureus biofilms. Cytotoxicity assays confirmed low toxicity toward L929 fibroblasts (≤31.2 µg·ml^-1) and minimal hemolytic activity (1-13%). These findings support the potential of these ruthenium complexes as candidates for novel therapies against staphylococcal infections.

Imaging techniques are important for biofilm studies. Biofilm samples should ideally be visualised with minimal sample preparation so as not to alter their original structure. However, this can be challenging and resource-intensive in most cases. This study details the development of a novel tool (Fortilife^™ Director^™) to visualise biofouling. The method utilises a microparticle suspension that effectively highlights biofilm boundaries without altering its structure, allowing for high-contrast, in-situ visualisation. Experimental applications across various membrane types, including reverse osmosis and nanofiltration, demonstrate the capability of the tool to quantify biofilm surface coverage accurately. Results from studies on different feed waters underline the effectiveness in evaluating biofouling severity and distribution patterns, correlating surface coverage with operational performance metrics such as pressure drop increase. The Fortilife^™ Director^™ represents a promising advancement in the management of biofouling in membrane filtration systems, offering a more reliable means of monitoring and optimising operational efficiency.