Biofouling significantly degrades vessel performance by increasing fuel consumption, harmful emissions (SO2, NOx, CO2), and maintenance costs, underscoring the role of effective fouling control coatings. However, the accuracy of antifouling coating performance assessments may be compromised by local fouling dynamics, particularly the influence of adjacent biofouled surfaces. This study investigates how proximity to pre-fouled panels coated with an epoxy primer affects biofouling settlement and growth on newly immersed coatings under both static and dynamic exposure conditions. Panels placed adjacent to heavily fouled surfaces exhibited accelerated colonization, with fouling coverage nearly doubling within three weeks compared to isolated controls. In static exposures, proximity led to the bypassing of early biofilm stages through lateral propagation via spores, sloughed fragments, and biofilm material. Under dynamic conditions, hydrodynamic forces amplified this effect, promoting faster dispersal and settlement, particularly of filamentous green and brown algae. These findings reveal that local propagation can significantly alter biofouling succession and growth rates, resulting in earlier community development and increased fouling intensity. Without careful spatial separation and test design, localized fouling pressure may be artificially elevated, leading to skewed interpretations of antifouling performance. Conversely, controlled propagation may serve as a tool for accelerated stress testing under high-biofouling conditions. This study emphasizes the need to account for biofouling propagation in experimental design to ensure reliable, reproducible antifouling evaluations.
Single-walled carbon nanotubes (SWCNTs) form intrinsically bundled networks due to strong intertube interactions, yet conventional debundling approaches can disrupt or chemically alter the nanotube structure. Here, Au@Pt nanorods (NRs) were progressively incorporated into SWCNT films as a nondestructive strategy to deliberately debundle the network while preserving the carbon framework and introducing Pt-rich catalytic sites. This approach was used to examine how network restructuring and metal decoration govern biofouling and electrochemical sensing. Increasing NR loading reorganized the SWCNT network into thinner strands, changed conductive pathways, and increased accessible surface features and hydrophilicity. These changes yielded analyte-dependent electrochemical responses: dopamine (DA) oxidation became more adsorption-controlled after debundling, with enhanced faradaic and capacitive currents attributed to improved interfacial accumulation at carbon-rich surfaces, whereas hydrogen peroxide (H2O2) oxidation was dominated by Pt-mediated catalysis and increased with NR loading due to higher catalytic site density. Biofouling studies with bovine serum albumin (BSA) showed that high NR contents promoted protein adsorption and suppressed electrochemical activity. Interestingly, DA oxidation was least affected on pristine SWCNT electrodes, whereas H2O2 detection benefited from intermediate NR decoration, indicating that biofouling can be mitigated by tailoring the platform to the target analyte to maintain performance after protein exposure, rather than relying on antifouling surfaces.
Injectable microparticles have great potential in tissue engineering and drug delivery. However, their clinical application is limited by the problem of biological contamination, and the inherent contradiction between anti-biofouling efficacy and colloid stability. Traditional strategies (such as drug release coatings and anti-biofouling polymer layers) have defects such as drug exhaustion, poor mechanical stability, and uneven surface coating. Herein, a design paradigm of nanoparticle-anchored "solid-like" slippery coating (SSCMP) was developed by constructing a composite interface layer with both topological structure and chemical anchoring functions on the surface of injectable microparticles, resolving the contradiction between anti-contamination and dispersibility. Specifically, an amide covalent coupling-surface limited self-assembly strategy was adopted to uniformly load amino-functionalized nanoparticles onto the surface of carboxylated microparticles. The nanoparticles exert a dual function: On the one hand, they form surface nano-protrusions, reducing direct particle contact and providing long-term monodispersity in the physiological environment. On the other hand, as lubrication anchor points, it captures silicone oil through electrostatic interaction and firmly locks the lubricants onto the surface of the microparticle through covalent grafting with epoxy resin, forming a stable "solid-like" slippery interface. The collaborative design endows the microparticles with persistent protein repulsion ability both in vitro and in vivo, broad-spectrum anti-biofouling performance against bacteria, significant cell adhesion inhibition effect. And it alleviates the inflammatory response caused by implantation, demonstrating excellent biocompatibility. This strategy breaks through the stability bottleneck of traditional coatings on curved substrates, providing a universal platform for the development of injectable biomaterials with controllable preparation, long-term anti-contamination, and great dispersibility.
Chlorine dioxide (ClO2) has attracted considerable attention as an alternative disinfectant for reverse osmosis (RO) pretreatment because of its broad-spectrum antimicrobial activity, effectiveness over a wide pH range, and lower formation of regulated disinfection by-products compared with conventional chlorination. These characteristics make ClO2 a promising strategy for mitigating microbial growth and supporting biofouling control in RO systems. However, the strong oxidative nature of ClO2 also presents a significant challenge, as prolonged exposure may induce degradation of the polyamide selective layer, resulting in deterioration of membrane integrity and filtration performance. This study investigated the effects of ClO2 concentration and solution pH on the degradation behavior and surface property changes of thin-film composite (TFC) polyamide RO membranes, with particular emphasis on their implications for biofouling control. Membrane performance and structural changes were evaluated using permeate flux measurements, scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (SEM-EDX), and contact angle analysis. The results demonstrated that increasing ClO2 concentration and alkaline conditions accelerated membrane degradation, as evidenced by increased permeate flux, pronounced surface deformation and cracking, disruption of the selective polyamide layer, changes in surface elemental composition, and significant alterations in wettability. The membrane exposed to 0.5 ppm ClO2 at pH 6 exhibited the least structural damage and maintained surface characteristics closest to those of the untreated membrane, indicating that this condition provided the most favorable balance between membrane preservation and operational performance. In contrast, exposure to higher ClO2 concentration and alkaline pH resulted in severe oxidative deterioration, which compromised membrane integrity despite the potential operational benefits associated with oxidant application. Although biofouling was not directly evaluated through microbial adhesion or biofilm formation experiments, the observed changes in membrane morphology, permeability, and wettability provide valuable insight into surface characteristics associated with fouling propensity. Overall, the findings highlight the importance of optimizing ClO2 dosage and operating pH to minimize oxidative membrane degradation while maintaining its practical advantages as a disinfectant in RO pretreatment, thereby providing guidance for improving membrane durability and supporting sustainable membrane-based water treatment.
Bio-inspired superhydrophobic surfaces are widely investigated for antibiofouling applications; however, they lack intrinsic bioactivity and provide passive resistance without eliminating planktonic or surface-adhered microbes. In this work, superhydrophobicity is integrated with bioactive nitric oxide (NO) generation from physiological levels of S-nitrosothiols (RSNOs) to provide combined antibiofouling under biologically relevant conditions. An optimized combination of non-fluorinated organosilane-modified micro- and nanosized zinc oxide (ZnO) and copper (Cu) particles within a siloxane matrix yields a durable coating on a polydimethylsiloxane substrate. The coating exhibits a surface roughness of 353 ± 26 nm and maintains water repellence following sand abrasion, water-jet, tape-peeling, and scratch test, with a contact angle >150° and hysteresis <2°. Upon exposure to physiological levels of S-nitrosoglutathione (GSNO) and glutathione (GSH), the coating demonstrates an 86.4 ± 4.0% increase in NO generation relative to controls, with fluxes matching endothelial NO production. The cytocompatible coating shows negligible metal leaching and excellent antibacterial activity, achieving ∼ 99.99% and 99.79% reductions in surface-adhered S. aureus and E. coli, respectively, and 89.43% and 69.80% reductions in planktonic S. aureus and E. coli, respectively. This work establishes a scalable strategy integrating non-adhesive superhydrophobicity with catalytic NO generation and demonstrates effective antimicrobial performance under physiologically relevant NO-generating conditions.
Cnidarian jellyfish-the medusa phase of medusozoans-are gaining recognition as important prey for a variety of predators in marine trophic webs. However, their traits as prey remain poorly understood. In this study, we examined the defensive traits of jellyfish, focusing specifically on cnidocyte-independent chemical defenses that serve as strategies against consumers, pathogens, and biofouling. To investigate these anti-consumer chemical defenses, we selected three sympatric jellyfish species: the hydromedusan Spirocodon saltatrix and the scyphomedusan moon jellyfish Aurelia coerulea as prey, and the scyphomedusan Japanese sea nettle Chrysaora pacifica as the predator. Using these species, we conducted feeding experiments, ablation of potential defensive organs, and analyses of compounds released by the prey. We found that: (1) in feeding experiments, S. saltatrix individuals exhibited an involution behavior, in which they strongly contracted and retracted their tentacles inside the umbrella when captured by C. pacifica, thereby escaping, whereas A. coerulea individuals were consumed without escaping; (2) a series of surgical ablation experiments indicated that the umbrella integument of S. saltatrix possesses a defensive function; (3) gas chromatography-mass spectrometry (GC-MS) analyses showed that S. saltatrix releases C8 to C9 alcohols and aldehydes when its integument is damaged; (4) behavioral experiments demonstrated that these compounds deter feeding by the predatory jellyfish; (5) these compounds inhibited biofilm formation by the sympatric bacterium Ectopseudomonas sp. isolated from sediment, indicating their antifouling role, though their effects on planktonic biofouling remain to be tested; and (6) the experimentally determined effective concentrations were higher than the bulk measured concentrations. Therefore, we hypothesize that the natural microscale concentrations of these compounds at the injured integument are sufficiently high to match the effective thresholds, suggesting that they function as defensive agents. Thus, our study demonstrates that S. saltatrix utilizes involution behavior and its integument to avoid predation. To our knowledge, this is the first report of exumbrellar integumental defense in a cnidarian jellyfish with suggestive evidence of chemical defense using oxidized derivatives of unsaturated fatty acids.
Microplastics in coastal waters provide persistent surfaces for microbial colonization and biofilm formation, supporting complex microbial assemblages known as the plastisphere. This study examines the plastisphere-biofouling nexus through a PRISMA-guided systematic review, bibliometric mapping, narrative-quantitative synthesis, and conceptual evidence integration of studies published between 2015 and 2025. From 1,248 records identified in Web of Science Core Collection and Scopus, 124 primary studies were retained for comparative synthesis. The reviewed evidence shows that microplastics frequently support distinct biofilm-associated microbial communities, although reported patterns vary across polymer type, exposure duration, environmental setting, microbial method, and biofilm measurement approach. Proteobacteria and Bacteroidetes were repeatedly reported among dominant bacterial groups, while opportunistic genera such as Vibrio and Pseudoalteromonas were detected in some plastisphere biofilms. Evidence for polymer-specific microbial diversity, contaminant retention, and environmental-driver effects remains context-dependent. Biofilm-coated microplastics may modify contaminant interactions under specific conditions, but current evidence does not support universal contaminant enhancement, confirmed pathogen transmission, or direct human health risk. This review identifies the plastisphere-biofouling nexus as an emerging ecological interface in coastal waters and highlights the need for standardized, field-relevant, and functionally validated studies.
Biofouling of titanium implants, initiated by nonspecific protein adsorption and followed by bacterial and cellular adhesion, remains a critical challenge that compromises long-term implant performance. Herein, we report a covalent interfacial engineering strategy to construct a robust zwitterionic sulfobetaine interface on titanium via a stepwise grafting approach. This method integrates phosphonate anchoring, maleic anhydride activation, and subsequent ring-opening immobilization of sulfonated amines, enabling the formation of a chemically stable and high-density zwitterionic layer directly on the titanium surface. X-ray photoelectron spectroscopy confirms the successful progression of each functionalization step and the formation of well-defined interfacial chemistry. The optimized surface exhibits superhydrophilicity with a water contact angle of 14.75° and demonstrates ultralow fouling characteristics. Specifically, the modified interface significantly suppresses adhesion of Escherichia coli, human fibroblasts, and blood components by 87, 89, and 96%, respectively, compared to pristine titanium. Mechanistically, the densely grafted zwitterionic sulfobetaine moieties generate a strongly hydrated interfacial network that effectively inhibits protein adsorption and subsequent biofouling cascades. Importantly, the covalent Ti-O-P anchoring and stable amide linkages impart excellent resistance to hydrolytic degradation, maintaining antifouling performance after prolonged immersion in aqueous and physiological environments for up to three weeks. This work establishes a simple yet highly effective platform for covalent immobilization of zwitterionic functionalities on inert metal surfaces, offering a scalable and durable solution for next-generation antifouling and bioinert titanium-based medical implants.
Antiscalants used in reverse osmosis (RO) desalination are commonly treated as simple operational additives, yet their chemical properties can significantly influence microbial dynamics, thereby creating a critical operational paradox. While antiscalants inhibit mineral scaling, they may simultaneously promote biofouling through poorly resolved mechanisms. Current vendor-driven selection prioritizes scaling control but overlooks microbial and environmental consequences. This opacity obscures molecular composition, impurity profiles, and transformation pathways, introducing uncertainty across the desalination lifecycle. Undisclosed chemical composition limits risk assessment, while interactions with marine microbial communities that drive biofouling lack mechanistic clarity. Emerging evidence indicates that antiscalants can both stimulate microbial growth via orthophosphate impurities, a readily bioavailable inorganic phosphorus source, and labile organic fractions, but may also inhibit growth through trace metal sequestration, particularly the sequestration of bioavailable iron, a metabolically essential micronutrient. The contribution of this inhibitory mechanism under seawater desalination conditions remains to be quantified. The net outcome is formulation-specific and environmental context-dependent. Beyond the treatment plant, the fate and impacts of discharged antiscalants remain insufficiently constrained, introducing uncertainty for marine ecosystems. We argue that antiscalant selection should shift from empirical practices to a predictive, mechanism-based strategy. Accordingly, we propose a Predictive Ecological Chemistry framework grounded in three principles: transparent chemical characterization, mechanistic evaluation of microbial responses, and environmental accountability. This framework offers a pathway toward data-driven selection that balances operational performance with ecological responsibility.
The growing demand for microalgae-derived products, driven by their antioxidant capacity and high value functional compounds, is intensifying the need for more efficient and durable cultivation systems. However, biofouling remains a critical bottleneck, reducing productivity and increasing operational costs in photobioreactors. Although several antifouling solutions have been proposed, most are opaque and therefore incompatible with light-dependent microalgal processes. In this work, the antifouling performance of two novel transparent materials was evaluated using four species of industrially relevant microalgae: Arthrospira platensis, Tetraselmis chuii, Chlorella sorokiniana, and Haematococcus pluvialis. Their performance was benchmarked against conventional substrates (glass and PMMA) and established coatings, including PDMS and the commercial opaque Hempasil X3®. A sequential experimental approach was adopted. First, the influence of culture media and the N / P molar ratio on biomass productivity and cell adhesion was evaluated to identify representative cultivation conditions. Subsequently, transparent antifouling surfaces were assessed under prolonged culture conditions using the selected nutrient conditions. The results demonstrate that the developed transparent surfaces (with a PEG/PDMS-based coating and PMMA-based rigid material) significantly reduce cell adhesion and protein accumulation under biofouling-promoting conditions, reaching values close to commercial antifouling coatings. Cell adhesion was strongly species-dependent, with C. sorokiniana and H. pluvialis exhibiting the highest adhesion. These materials reduced microalgal adhesion by 45-74 % compared to conventional transparent materials such as PMMA and glass while maintaining high optical transparency within the visible range. Therefore, these transparent materials emerge as a promising strategy to enhance the efficiency, stability, and longevity of microalgae cultivation systems.
Systemic antibiotics are the standard of care for acute bacterial skin and skin structure infections (ABSSSI), but low drug perfusion at the site of infection and higher rates of antibiotic resistance necessitate alternative strategies to enhance local antibiotic concentrations. Wound dressings provide a convenient approach to antibiotic delivery but are limited by fixed, pre-loaded antibiotic concentrations. We have recently demonstrated the use of glutathione-conjugated poly(ethylene glycol) [GSH-PEG] hydrogels for the loading and release of charge-bearing therapeutic molecules. Herein, we evaluate the antibacterial and antibiofilm activities of rationally selected therapeutics released from GSH-PEG hydrogels. Antibiotics released from GSH-PEG hydrogels inhibited the growth of Pseudomonas aeruginosa and Staphylococcus aureus and effectively reduced biofilm formation without significantly influencing human dermal fibroblast proliferation and migration. In addition to controlled antibiotic delivery, GSH-conjugated hydrogels demonstrated markedly lower albumin and bacterial adsorption as compared to unconjugated hydrogels and a traditional wound dressing. The zwitterionic GSH ligands within hydrogels permit selective therapeutic delivery while reducing biofouling, highlighting the GSH-PEG hydrogel platform as a promising candidate for use as a wound dressing material.
Laundry-derived microplastic fibers are major source of environmental microplastic pollution. Because conventional wastewater treatment processes cannot completely remove fibrous microplastics, washing machine-mounted filters have been developed as a promising source-control approach for the reduction in microfiber emissions. This review thus summarizes recent advances in external filtration systems and membrane-based technologies for laundry wastewater treatment. The characteristics of laundry wastewater, microfiber release behavior, and recent regulatory trends are discussed together with the performance of commercially available filtration systems. The applicability of advanced membrane materials, including ceramic membranes, for high-efficiency microfiber separation is also highlighted. Particular attention is given to the microbial contamination and biofouling of microplastic filters, which can affect their filtration efficiency, operational stability, and household hygiene. This review also discusses the potential reuse of captured microplastics for membrane fabrication as a sustainable pathway for waste valorization and circular resource utilization. Finally, current limitations and future perspectives for the development of efficient, hygienic, and sustainable laundry microplastic filtration technologies are discussed.
Marine biofouling is a major environmental and economic challenge for shipping and marine infrastructure, driving the need for effective and sustainable antifouling strategies. In this study, bio-based amphiphilic-designed polymer coatings were synthesized from renewable platform chemicals via an energy-efficient free-radical polymerization approach, thereby avoiding hazardous solvents. The coatings were designed by tuning the hydrophilic-hydrophobic balance to modulate antifouling performance, with crosslinking introduced in selected formulations to improve coating integrity and durability. Polymer synthesis proceeded with high yields (65-83%) and almost successful monomer incorporation, resulting in coatings with suitable chemical properties, controlled surface wettability (>90°), and no detectable acute toxicity against Artemia sp. The environmental sustainability of the synthetic approach was evaluated using green chemistry metrics, including solvent recovery sensitivity scenarios. At the same time, a preliminary user-perception survey was conducted to assess the practical relevance and societal demand for safer antifouling solutions. Laboratory assays revealed strong inhibition of diatom adhesion in predominantly hydrophobic formulations (>90% inhibition), whereas amphiphilic-designed systems exhibited variable, formulation-dependent performance. Static field exposure on PVC panels showed that the tested amphiphilic formulations did not prevent fouling accumulation under prolonged natural immersion, as both microfouling and macrofouling communities developed similarly to those on untreated panels. Microbial community analyses further indicated that bacterial assemblages were more responsive to coating chemistry than fungal communities during early colonization. These results demonstrate the importance of combining renewable feedstocks, green synthesis and multilevel assessment to identify promising bio-based antifouling coatings and guide their future optimization for suitable applications.
Marine biofouling communities constitute a rich reservoir of microbial diversity and represent a promising source of bioactive metabolites. In this study, we investigated culturable epibiotic bacteria associated with fouling invertebrates from the Marina in northern Tunisia, with a focus on their enzymatic activities, antimicrobial potential, and antibiotic resistance profiles. A total of 52 bacterial isolates were recovered from 23 fouling invertebrate hosts and characterized using DNA barcoding and molecular identification. The epibiotic culturable bacterial community was dominated by members of the genera Vibrio, Photobacterium, Halomonas, and Pseudomonas. Enzymatic screening revealed a high hydrolytic potential, with DNase (71.2%), lipase (65.4%), and gelatinase (59.6%) being the most prevalent activities. Antimicrobial assays showed that a substantial proportion of isolates exhibited inhibitory activity against at least one pathogenic indicator strain, whereas antibiotic susceptibility testing revealed frequent resistance, particularly to fosfomycin and cefoxitin. Together, these findings highlight the dual nature of epibiotic culturable bacteria in the Marina in northern Tunisia, acting both as a reservoir of biotechnologically valuable antimicrobial producers and as potential carriers of antibiotic resistance, underscoring their ecological relevance and public health significance in Mediterranean coastal ecosystems.
The application of quorum quenching (QQ) bacteria for fouling control in membrane bioreactors (MBRs) is often hampered by the gradual loss of biological activity during operation. Here, this limitation is overcome by combining a newly isolated QQ bacterium (Pseudomonas knackmussii HITSZ-Q1) with a low-cost biochar-reinforced polyvinyl alcohol/sodium alginate (PVA/SA/BC) immobilization matrix. The strain completely degraded N-octanoyl-l-homoserine lactone (C8-HSL) and N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C12-HSL) within 2 h via intracellular acylase, maintained stable QQ activity at 30-40 °C and pH 6-8, and inhibited Pseudomonas aeruginosa biofilm formation by approximately 30%. Biochar incorporation enhanced the hydrogen-bonding network, compressive strength, and adsorption capacity of the matrix, providing a protective microenvironment for strain Q1. In flask tests, the PVA/SA/BC QQ beads maintained integrity over six reuse cycles and retained >40% degradation activity for both AHLs after 90 days of storage at 4 °C. When applied in lab-scale MBRs, the QQ beads delayed membrane fouling by 69% without compromising effluent quality, which correlated with a 50% reduction in C8-HSL, decreased polysaccharide and protein contents in extracellular polymeric substances, and an altered microbial community. Notably, after 34 days of continuous operation, the recovered PVA/SA/BC QQ beads showed increased quenching activity, with degradation rates for C8-HSL and 3-oxo-C12-HSL rising by a further 13% and 4%, respectively, a phenomenon rarely reported in QQ systems. This work offers a practical and durable QQ strategy that turns the activity decay problem into sustained, and even slightly enhanced, biofouling control.
In this study, a novel waterborne polyurethane coating (BV-PDx) with dual-action (dynamic and static) antifouling efficacy was innovatively developed by incorporating polydimethylsiloxane (PDMS) as side chains and covalently grafting quaternary ammonium salts into the backbone. The highly flexible PDMS side chains not only reduce the surface energy and elastic modulus of the material but also endow the coating with superior dynamic fouling-release performance under hydrodynamic shear force. Simultaneously, the incorporated cationic active groups effectively address the limitations of pure siloxane systems in static environments through a nonleaching "contact-killing" mechanism. The coatings demonstrate broad-spectrum antifouling against Escherichia coli, Staphylococcus aureus, and Phaeodactylum tricornutum. Moreover, the mechanical properties can be effectively tuned by systematically adjusting the molecular weight of the PDMS segments. This research offers an innovative structural design strategy for the development of eco-friendly and durable marine antifouling materials adaptable to complex underwater environments.
Microplastics (MPs) are pervasive pollutants in aquatic environments, and understanding their transport dynamics is critical for assessing environmental risks. This study represents a pioneering analysis of the threshold of MP incipient motion. By conceptualizing biofilm as an enhancement of surface roughness, we find that biofilm influences the incipient motion of MPs by altering the coefficient of static friction (μs).The dependence of the μs on the biofilm thickness is formulated empirically, and the associated increase in the critical Shields number (θc) for MPs is then determined. Furthermore, factors affecting the θc of MPs, such as particle shape, size, biofilm on the surface, and exposure conditions are systematically integrated into a semi-theoretical model by 45 incipient motion experiments and data extracted from published literature. The theoretical component is grounded in force balance analysis, while model coefficients are empirically calibrated using experimental results. Comparison with existing empirical models demonstrates that the proposed framework offers improved robustness and predictive capability for assessing the incipient motion of biofouled MPs.
This work proposed the mitigation of biofilm growth on the water showering system (WSS) in a semiconductor factory through phosphorus limitation. Biofilm development on the WSS was monitored and characterized under simulated systems for >300 days with feed water (P-control, 20 μg/L as PO43--P) and treated water by ion exchange resin (P-Limit, < 2 μg/L as PO43--P). Results from confocal laser scanning microscopy (CLSM) analysis showed that biofilm formation on the WSS was dramatically reduced under the P-Limit, exhibiting a lower volume (13.2 ± 3.7 vs. 26.3 ± 4.7 μm³/μm²) and growth rate (0.0474 vs. 0.0945 μm/day) than under the P-Control, while displaying a more porous and rougher biofilm structure. The mechanical properties of extracellular polymeric substances (EPS), investigated using atomic force microscopy (AFM), revealed a lower EPS cohesion force under the P-Limit (-0.43 nN) than under the P-Control (-0.98 nN). In addition, EPS composition and functional groups measured via Fourier transform infrared (FTIR) spectroscopy showed that phosphorus limitation reduced carbohydrate-associated functional groups related to biofilm cohesion and adhesion, suggesting that carbohydrates are key determinants of EPS cohesion and adhesion. Furthermore, fluorescence excitation-emission matrix (FEEM) coupled with parallel factor analysis (PARAFAC) revealed decreased protein-like and microbial degradation product-associated signals under the P-Limit, which was associated with reduced biofilm development. Overall, our findings suggest that phosphorus limitation effectively controlled biofilm development in the WSS, potentially by weakening EPS mechanical properties and shifting microbial metabolic activity.
Biofouling and microenvironmental deterioration are major bottlenecks restricting the intensive aquaculture of Pacific abalone (Haliotis discus hannai). While co-culturing offers an eco-friendly mitigation strategy, the underlying mechanisms promoting abalone growth remain poorly understood. This study evaluated the growth performance of H. d. hannai co-cultured with varying densities of the sea urchin (Strongylocentrotus intermedius). By employing transcriptome and 16S rRNA sequencing of the abalone gut, we investigated the synergistic responses of host gene expression and gut microbiota. Compared with the monoculture group, the co-culture groups showed significantly less biofouling and greater growth of abalone, with the co-culture (n = 15) exhibiting the best outcomes. Transcriptomic analysis revealed 1444, 760, and 508 DEGs in G5, G10, and G15, respectively, compared with G0. These DEGs were significantly enriched in metabolic pathways, including glycolysis and sterol metabolism, indicating a shift in intestinal energy metabolism from stress defense toward growth under co-culture conditions. Gut microbiota profiling identified Proteobacteria and Firmicutes as the dominant phyla, with specific functional taxa (e.g., Psychrilyobacter and Akkermansia) enriched in a density-dependent manner. Furthermore, correlation analysis demonstrated that growth traits positively correlated with growth-promoting taxa (e.g., the unclassified AB1 lineage), but negatively correlated with potentially opportunistic taxa (e.g., Tabrizicola). These findings provide insights into a potential synergistic mechanism of "environmental stress alleviation-metabolic reprogramming-microecological remodeling" driving abalone growth, providing a theoretical foundation for optimizing co-culture systems and developing growth-associated biomarkers.
Marine biofouling and corrosion remain major challenges for ships and offshore infrastructure, increasing maintenance costs and reducing operational efficiency. However, biofouling in marine environments can have detrimental effects on materials. Amphiphilic coatings, which combine hydrophobic and hydrophilic properties, represent a promising class of anti-fouling materials. These coatings can reduce organism-surface interactions and suppress bioadhesion through the formation of a hydration layer. To achieve long-term and stable anti-fouling performance, we designed and fabricated an amphiphilic coating with a dual-network cross-linked structure (HPTE). By incorporating TMAO, an amphiphilic component that strongly interacts with water, the coating constructs a hydrated protective film on its surface. This layer protects the substrate from corrosion and damage induced by marine pollutants. The densely interwoven structure, enabled by abundant cross-linking sites, endows the coating with a high Young's modulus (1 GPa), excellent adhesion strength (∼4.81 MPa), and outstanding durability (withstanding 500 cycles of cotton abrasion). In a 20-day diatom adhesion test, the adhesion rate of chlorella on HPTE was only 51.2 cells per mm2. This study provides a promising strategy for developing environmentally friendly and highly efficient anti-fouling coatings for marine applications.