Unveiling the impacts of salts on halotolerant bacteria during filtration: A new perspective on membrane biofouling formation in MBR treating high-saline organic wastewater.

In recent decades, membrane bioreactor (MBR) has been prevalently employed to treat high-saline organic wastewater, where the halotolerant microorganisms should be intensively utilized. However, limited works were devoted to investigating the biofouling characteristics from the perspective of the relationship between halotolerant bacteria and salts. This work filled the knowledge gap by exploring the biofouling formation mechanisms affected by high salinity. The results showed that the amount of negative charge on halotolerant bacteria surface was significantly reduced by high content of NaCl, probably leading to the obvious cell agglomeration. Despite the normal proliferation, the halotolerant bacteria still produced substantial EPS triggered by high salinity. Compared with the case of control without salt addition, the enhanced biofouling development was observed under high-saline conditions, with the fouling mechanism dramatically transformed from cake filtration to intermediate blocking. It was inferred that the halotolerant bacteria initially adhered on membrane created an extra filter layer, which contributed to the subsequent NaCl retention, resulting in the simultaneous occurrences of pore blockage and cake layer formation because of NaCl deposition both on membrane pores as well as on biofilm layer. Under high-saline environment, remarkable salt crystallization occurred on the biofilm layer, with more protein secreted by the attached halotolerant bacteria. Consequently, the potential mechanisms for the enhanced biofouling formation influenced by high salinity were proposed, which should provide new insights and enlightenments on fouling control strategies for MBR operation when treating high-saline organic wastewater.

The biodegradation of polylactic acid microplastic and their toxic effect after biofouling in activate sludge.

Biodegradable microplastics (MPs) can form biofilms through interactions with various microorganisms in aquatic system and can be exposed to organisms. This study first investigated biodegradability of polylactic acid (PLA) MPs and the characterization of PLA MPs before/after biofouling (4 weeks) and their toxic effects on the freshwater invertebrate Daphnia magna. The biodegradability rate of PLA MPs was up to 50% over 28 days, suggesting that even biodegradable MPs do not easily decompose under environmental conditions. Furthermore, biofouling of MPs led to an increase in size and, in the process, induced an additional functional peak in the PLA MPs. The exposure of biofouled MPs did not lead to a reduction in survival, reproduction, or growth during chronic exposure, nor did it cause feeding inhibition in juvenile (<4 days old) D. magna. However, pristine MPs significantly reduced survival, reproduction, and growth at concentrations of 5.0 mg L-1. Overall, pristine MPs caused inhibition of reproduction and growth and high mortality in D. magna, while the biofouling process did not induce these effects. Our findings highlight the complex interactions between MPs and biological components in aquatic environments, emphasizing the importance of considering biofouling dynamics when assessing the ecological impacts of biodegradable MPs.

Harnessing Nature-Inspired Catechol Amino Acid to Engineer Sticky Proteins and Bacteria.

3,4-Dihydroxy-L-phenylalanine (DOPA) serves as a post-translational modification amino acid present in mussel foot proteins. Mussels exploit the exceptional adhesive properties of DOPA to adhere to a wide range of surfaces. This study presents the development of sticky proteins and bacteria through the site-specific incorporation of DOPA using Genetic Code Expansion Technology. Through the optimization of the DOPA incorporation system, proteins containing DOPA demonstrate significantly improved binding abilities to various organic and metallic materials. The material-binding capabilities of DOPA to combat different types of biofoulings are harnessed by integrating it into intrinsically disordered proteins. Beyond the creation of adhesive proteins for anti-biofouling purposes, this highly efficient DOPA incorporation system is also applied to engineer adhesive bacteria, resulting in a remarkable increase in their binding capability to diverse materials including 400 folds of improvement to polyethylene terephthalate (PET). This substantial enhancement in PET binding of these bacteria has allowed to develop a unique approach for PET degradation, showcasing the innovative application of Genetic Code Expansion in cell engineering.

Antifouling activity and ecotoxicological profile of the cyanobacterial oxadiazine nocuolin A.

Pursuing effective and biocompatible natural compounds to supplant current biocidal antifouling (AF) technologies remains crucial and challenging. Among natural products hosts, cyanobacteria are recognized as producers of bioactive secondary metabolites that are underexplored in terms of anti-biofilm and AF potential. Nocuolin A, a natural oxadiazine previously isolated and known to be produced by different cyanobacterial strains, has demonstrated bioactive potential, particularly against tumor cell lines. Considering this potential and its exquisite chemical structure, here nocuolin A was investigated as a potential natural AF agent through an integrative approach including AF bioactivity testing across distinct levels of biological organization, mode of action assessment, ecotoxicity evaluation, and ecological risk predictions. Nocuolin A was found to inhibit the settlement of mussel (Mytilus galloprovincialis) plantigrades (EC50 = 3.905 µM) while showing no toxicity to this biofouling species (LC50 > 100 µM). Additionally, while exhibiting no inhibitory activity against the growth of five marine biofilm-forming bacterial strains, it significantly suppressed the growth of the marine biofilm-forming diatom Navicula sp. (EC50 = 1.561 µM), and had a lethal effect on this diatom species (>3.1 µM). The AF targets of nocuolin A on mussel plantigrades revealed no correlation with acetylcholinesterase and tyrosinase metabolic processes; however, proteins involved in oxidative stress, muscle regulation, and energy production were highlighted. The results also provide insights into the ecological risk of nocuolin A, including its ecotoxicity against Artemia salina nauplii (LC50 = 2.480 µM), Amphibalanus amphitrite nauplii (LC50 = 0.0162 µM), and Danio rerio embryos (LC50 = 0.0584 µM). When matching these results with simulated environmental values, nocuolin A was deemed a considerable threat to the ecosystems. While this research highlights the AF activity of nocuolin A, it also emphasizes the potential adverse environmental impact when applied in preventive coatings.

How plastic litter sunk by biofouling recovers buoyancy - The role of benthic predation.

Estimates suggest that the amount of plastic litter discarded in the ocean is several times greater than what remains floating at the sea surface, raising questions about the fate of this marine debris. Fouling-induced sinking of plastic litter is one of the proposed mechanisms responsible for this mass difference. While some of this 'missing' plastic mass may be explained by the effects of fouling, it has also been hypothesized that sinking litter may return to the surface after benthic organisms consume the biofouling. However, this hypothesis has never been tested. The present study evaluated the structure and biomass of the fouling community in response to benthic predation in both summer and winter seasons. Floating PVC plates were installed during winter and summer in central Chile (36°S) until the growing biofouling community caused them to sink. Plates were then moved to the seabed, where they were exposed to benthic predation, while control plates were maintained in a mesh cage impeding predator access. In summer, all plates recovered their buoyancy, while in the winter only 60 % recovered buoyancy. All caged control samples remained on the bottom in both seasons. The community structure differed both in the treatments and across the seasons, with plates that recovered buoyancy initially being dominated by Ulva sp. and Ciona robusta. Conversely, plates that did not refloat were mainly covered by species resistant to predation such as Pyura chilensis, Austromegabalanus psittacus, and Balanus laevis. Thus, fouling community structure influences how predation facilitates buoyancy recovery, because not all epibionts can be consumed by predators. While previous studies had shown how fouling organisms cause sinking of floating litter, this is the first study to provide experimental evidence that predation can reverse this process and allow litter to resurface and become again available as dispersal vectors for native and invasive species.

Guardians of Future Food Safety: Innovative Applications and Advancements in Anti-biofouling Materials.

Biofilm formation is a widespread natural phenomenon that poses a substantial threat to food microbiological safety, with direct implications for consumer health. To combat this challenge effectively, one promising strategy involves the development of functional anti-biofouling layers on food-contact surfaces to deter microbial adhesion. Herein, we explore the methodologies for fabricating both hydrophilic and hydrophobic anti-biofouling materials, along with a detailed examination of their inherent antiadhesive mechanisms. Furthermore, we provide concise insights into exemplary applications of anti-biofouling materials within the context of the food industry. This comprehensive analysis not only advances our understanding of biofilm prevention but also sets the stage for innovative developments in anti-biofouling materials and their future applications in food science. These advancements hold the potential to significantly enhance food microbiological safety, ensuring that consumers can confidently enjoy food products of the highest standards in terms of hygiene and quality.

Anti-Biofouling Polyzwitterion-Poly(amidoxime) Composite Hydrogel for Highly Enhanced Uranium Extraction from Seawater.

Amidoxime-functionalized hydrogels are one of most promising adsorbents for high-efficiency uranium (U) extraction from seawater, but bioadhesion on their surface seriously decreases their adsorption efficiency and largely shortens their service life. Herein, a semi-interpenetrating zwitterion-poly(amidoxime) (ZW-PAO) hydrogel was explored through introducing a PAO polymer into a poly [3-(dimethyl 4-vinylbenzyl amino) propyl sulfonate] (PDVBAP) polyzwitterionic (PZW) network via ultraviolet (UV) polymerization. Owing to the anti-polyelectrolyte effect of the PZW network, this ZW-PAO hydrogel can provide excellent super-hydrophilicity in seawater for high-efficiency U-adsorption from seawater. Furthermore, the ZW-PAO hydrogel had outstanding anti-biofouling performance for both highly enhanced U-adsorption and a relatively long working life in natural seawater. As a result, during only 25 days in seawater (without filtering bacteria), the U-uptake amount of this ZW-PAO hydrogel can reach 9.38 mg/g and its average rate can reach 0.375 mg/(g∙day), which is excellent among reported adsorbents. This work has explored a promising hydrogel for high-efficiency U-recovery from natural seawater and will inspire new strategy for U-adsorbing materials.

A Chemical Toolbox to Unveil Synthetic Nature-Inspired Antifouling (NIAF) Compounds.

The current scenario of antifouling (AF) strategies to prevent the natural process of marine biofouling is based in the use of antifouling paints containing different active ingredients, believed to be harmful to the marine environment. Compounds called booster biocides are being used with copper as an alternative to the traditionally used tributyltin (TBT); however, some of them were recently found to accumulate in coastal waters at levels that are deleterious for marine organisms. More ecological alternatives were pursued, some of them based on the marine organism mechanisms' production of specialized metabolites with AF activity. However, despite the investment in research on AF natural products and their synthetic analogues, many studies showed that natural AF alternatives do not perform as well as the traditional metal-based ones. In the search for AF agents with better performance and to understand which molecular motifs were responsible for the AF activity of natural compounds, synthetic analogues were produced and investigated for structure-AF activity relationship studies. This review is a comprehensive compilation of AF compounds synthesized in the last two decades with highlights on the data concerning their structure-activity relationship, providing a chemical toolbox for researchers to develop efficient nature-inspired AF agents.

Application of Online Flow Cytometry for Early Biofouling Detection in Reverse Osmosis Membrane Systems.

Biofouling poses a significant challenge to reverse osmosis (RO) membrane systems, necessitating timely detection for effective control. This study evaluated the efficacy of flow cytometry (FCM) for early biofilm detection in comparison to conventional system performance indicators. Feed channel pressure drop and total cell concentration in the Membrane Fouling Simulator (MFS) flowcell cross-flow outlet water were monitored over time as early biofouling indicators. The results demonstrated the potential of increased bacterial cell concentration in cross-flow outlet water as a reliable indicator of biofouling development on the membrane. Water outlet monitoring enabled faster biofouling detection compared to feed channel pressure drop. Membrane autopsy confirmed biofilm presence prior to the pressure drop increase, highlighting the advantage of early detection in implementing corrective measures. Timely intervention reduces operational costs and energy consumption in membrane-based processes.

Combination of a membrane bioreactor with a rotating biological contactor holding several diverse metazoans can reduce excess sludge with fouling mitigation.

In a membrane bioreactor (MBR) system, in situ sludge reduction techniques induce membrane fouling. To address this challenge, we incorporated a rotating mesh carrier, which can adsorb organic matter and provide a habitat for metazoans, into the anoxic tank of a conventional anoxic/oxic-MBR (A/O-MBR) system, termed rotating biological contactor-MBR (RBC-MBR), and evaluated treatment performance. Over 151 days, lab-scale RBC-MBR and A/O-MBR were used to treat municipal sewage. Both reactors showed similar COD and NH4+ removal rates. However, RBC-MBR reduced excess sludge by approximately 45 % compared with A/O-MBR. Microscopic observation and 18S rRNA gene-based microbial analysis revealed the persistence of microfauna and metazoans (oligochaetes, nematodes, and rotifers) in RBC, which are typically absent in activated sludge. Additionally, the metazoan's population in the RBC-MBR membrane tank was two-fold that of A/O-MBR, indicating enhanced sludge reduction through predation. Despite these reductions, the increase in transmembrane pressure was similar between RBC-MBR and A/O-MBR, suggesting that sludge holding by RBC mesh media degrade fouling substances, such as proteins and polysaccharides and improves sludge filterability, resulting in membrane fouling mitigation. Microbial communities in both reactors were similar, indicating that the installation of RBC did not alter the microbial community of sludge. Network analysis suggested potential symbiotic or prey-predator relationships between bacteria and metazoans. This study reveals that RBC-MBR effectively reduced the excess sludge while mitigating membrane fouling, highlighting one of the promising technology for applying metazoan predation into MBR.

Robust Chiral Metal-Organic Framework Coatings for Self-Activating and Sustainable Biofouling Mitigation.

Surface coatings are designed to mitigate pervasive biofouling herald, a new era of surface protection in complex biological environments. However, existing strategies are plagued by persistent and recurrent biofilm attachment, despite the use of bactericidal agents. Herein, a chiral metal-organic framework (MOF)-based coating with conformal microstructures to enable a new anti-biofouling mode that involves spontaneous biofilm disassembly followed by bacterial eradication is developed. A facile and universal metal-polyphenol network (MPN) is designed to robustly anchor the MOF nanoarmor of biocidal Cu2+ ions and anti-biofilm d-amino acid ligands to a variety of substrates across different material categories and surface topologies. Incorporating a diverse array of chiral amino acids endows the resultant coatings with widespread signals for biofilm dispersal, facilitating copper-catalyzed chemodynamic reactions and inherent mechano-bactericidal activities. This synergistic mechanism yields unprecedented anti-biofouling efficacy elucidated by RNA-sequencing transcriptomics analysis, enhancing broad-spectrum antibacterial activities, preventing biofilm formation, and destroying mature biofilms. Additionally, the chelation-directed amorphous/crystalline coatings can activate photoluminescent properties to inhibit the settlement of microalgae biofilms. This study provides a distinctive perspective on chirality-enhanced antimicrobial behaviors and pioneers a rational pathway toward developing next-generation anti-biofouling coatings for diverse applications.

A Liquid Metal-Based Temperature-Responsive Low-Toxic Smart Coating for Anti-Biofouling Applications in Marine Engineering.

Titanium alloys have been widely used in marine engineering fields. However, because of high biocompatibility, they are vulnerable to biofouling. In this work, based on the micro-arc oxidation technology and spontaneous galvanic replacement reaction, a temperature-responsive low-toxic smart coating consisting of liquid metal particles is designed to control the release of Ga3+, Cu2+, and Cu1+ ions in different temperatures. This technology can ensure the full release of active ingredients within the target temperature range, intelligently maintaining the excellent anti-biofouling performance, while saving active ingredients. After being immersed in culture media with Sulfate-Reducing Bacteria (SRB) for 14 days at 10, 20, and 30 °C, at the optimal activity temperature of 30 °C for SRB, the best sample releases the highest amounts of Ga3+, Cu2+, and Cu1+ ions, demonstrating a 99.9% bactericidal rate. When the temperature decreases to 10 °C, the activity level of SRB is very low, and the smart coating can also reduce the released ions correspondingly, still with a 97.3% bactericidal rate. The remarkable anti-biofouling performance is attributed to the physical damage and lethal ions interaction. Furthermore, the best sample exhibits good corrosion resistance. This work presents a design route for smart anti-biofouling coatings for temperature-responsive.

Durable photobioreactor antibiofouling coatings for microalgae cultivation by photoreactive poly(2,2,2-trifluoroethyl methacrylate).

To improve the durability of the photobioreactor antibiofouling surface for microalgal cultivation, a series of photoreactive poly(2,2,2-trifluoroethyl methacrylate) (PTFEMA) were successfully synthesized and used to modify ethylene-vinyl acetate (EVA) films by a surface coating and UV light grafting method. Fourier transform infrared (FT-IR) spectra, X-ray photoelectron spectroscopy analysis (XPS) and fluorescence microscopy results indicated that PTFEMA were fixed successfully onto the EVA film surface through a covalent bond. During the microalgal adhesion assay, the number of EVA-PTFEMA film-adhered microalgae was 41.4% lower than that of the EVA film. Moreover, the number of microalgae attached to the EVA-PTFEMA film decreased by 61.7% after cleaning, while that of EVA film decreased by only 49.1%. It was found that the contact angle of EVA-PTFEMA film surface increased, and remained stable when immersed in acid and alkali solution for up to 90 days.HIGHLIGHTSDurable photobioreactor antibiofouling surfaces for microalgal cultivation were prepared successfully.The contact angle of antibiofouling coating surface remained stable in acid and base environment for 90 days.The attached microalgae on antibiofouling surface decreased 41.4% than those of unmodified surface.The attached microalgae on antibiofouling surface could be cleaned by 61.7% through changing the flow velocity of microalgal suspension.

Modelling passive sampling of hydrophilic compounds under time-variable aqueous concentrations.

Passive sampling is a crucial method for evaluating concentrations of hydrophilic organic compounds in the aquatic environment, but it is insufficiently understood to what extent passive samplers capture the intermittent emissions that frequently occur for this group of compounds. In the present study, silicone sheets and styrene-divinyl benzene-reversed phase sulfonated extraction disks with and without a polyethersulfone membrane were exposed under semi-field conditions in a 31 m3 flume at three different flow velocities. Natural processes and spiking/dilution measures caused aqueous concentrations to vary strongly with time. The data were analyzed using two analytical models that account for these time-variable concentrations: a sampling rate model and a diffusion model. The diffusion model generally gave a better fit of the data than the sampling rate model, but the difference in residual errors was quite small (median errors of 19 vs. 25% for silicone and 22 vs. 25% for SDB-RPS samplers). The sampling rate model was therefore adequate enough to evaluate the time-integrative capabilities of the samplers. Sampler performance was best for SDB-RPS samplers with a polyethersulfone membrane, despite the occurrence of lag times for some compounds (0.1 to 0.4 days). Sampling rates for this design also spanned a narrower range (80 to 110 mL/day) than SDB-RPS samplers without a membrane (100 to 660 mL/day). The effect of biofouling was similar for all compounds and was consistent with a biofouling layer thickness of 150 µm.

On-site evaluation of DGT passive sampling for quantitatively measuring per- and polyfluoroalkyl substances in a river-estuary-sea water system.

The passive sampling technique of diffusive gradients in thin-films (DGT) is promising for monitoring emerging contaminants such as per- and polyfluoroalkyl substances (PFAS). It is urgent to evaluate the impacts of salinity and exposure time on DGT sampling before it can be set as a standard method. Herein, DGT sampler based on the binding gel of weak anion exchanger (WAX) resin was deployed in a representative water system of the Xiaoqing river-estuary-sea for representative sampling windows (<1 day to 28 days) with high pH (8.18 ± 0.04 to 8.51 ± 0.17) and wide ranges of salinity (0.95 ± 0.07‰ to 14.37 ± 3.92‰), total dissolved solids (1.20 ± 0.09 g/L to 15.29 ± 3.91 g/L) and dissolved organic matter (2.8-32 mg/L). The results showed that the WAX-DGT sampler exhibited good performance for most target PFAS except for short-chain perfluorocarboxylates (C ≤ 5) in 14 days. When the exposure time was over 14 days, biofouling of the sampler may deflect the mass accumulation of the PFAS in the sampler. Salinity played an important role in the mass binding of PFAS by DGT. The shorter the carbon chain of the compound, the greater the influence of the salinity. PFAS with carboxyl groups had greater affinities for the biofouled membrane filter than those with sulfonic groups. In the river-estuary-sea system, where PFAS concentrations changed dynamically, the temporal resolution of the monitoring strategy has been demonstrated to be more important than spatial resolution. DGT provided a better integral of PFAS exposure than grab sampling in the dynamic water system and offered equivalent sensitivity of grab sampling with exposure time <10 d and greater sensitivity with exposure time ≥10 d. Thus, DGT has the advantage of providing high temporal resolution monitoring. This study provided support for the standardization of the DGT technique.

Assessment of plastic debris and biofouling in a specially protected area of the Antarctic Peninsula region.

The aim of this paper is to characterize the plastic and to study a potential relationship between plastic debris characteristics and the presence of fouling biota in an Antarctic Specially Protected Area Robert Island, on the Antarctic peninsula region. A combination of lab-based sorting, advanced spectral analysis and general linear modelling was used to assess the abundance and type of plastic debris washed up on the shore. Observations recorded 730 debris items, with 85 % being plastic. Polystyrene (PS) and Polyethylene terephthalate (PET) were the dominant plastics (61 %). Biofouling was observed on 25 % of plastic debris, with debris complexity and degradation significantly increasing the likelihood of fouling occurring. There was no correlation found between biofouling type and plastic polymer type. Findings raise concerns that even with the highest level of environmental protection, an external marine-based source of pollution can intrude the coastal habitat, with uncertain consequences to local flora and fauna.

Bioinspired Sulfobetaine Borneol Fluorinated Amphiphilic Polymers for Marine Antifouling and Fouling Release Applications.

The development of nontoxic antifouling coatings in static marine environments is urgent. Herein, the successful synthesis of sulfobetaine borneol fluorinated polymers (PEASBF) by a free radical polymerization method is reported. The PEASBF coatings exhibit outstanding antifouling activity, which effectively resists the adhesion of Bovine serum albumin (FITC-BSA adhesion rate: 0.5%), Pseudomonas sp. (Biofilm: 1.3 absorbance) and Navicula sp. (Diatom attachment rate: 33%). More importantly, the PEASBF coatings display outstanding fouling release properties, achieving a release rate of 98% for Navicula sp., and the absorbance of the Pseudomonas sp. biofilm is only 0.2 under 10 Pa shear stress. XPS and MD studies showed that the fluorinated/isobornyl groups induce more sulfobetaine groups to migrate toward polymer surfaces for intensify antifouling. Additionally, the chiral stereochemical structure of borneol enhances antifouling and fouling release ability of amphiphilic polymers. Therefore, the PEASBF has the potential for static marine antifouling applications.

Quaternary Ammonium Salts-Based Materials: A Review on Environmental Toxicity, Anti-Fouling Mechanisms and Applications in Marine and Water Treatment Industries.

The adherence of pathogenic microorganisms to surfaces and their association to form antibiotic-resistant biofilms threatens public health and affects several industrial sectors with significant economic losses. For this reason, the medical, pharmaceutical and materials science communities are exploring more effective anti-fouling approaches. This review focuses on the anti-fouling properties, structure-activity relationships and environmental toxicity of quaternary ammonium salts (QAS) and, as a subclass, ionic liquid compounds. Greener alternatives such as QAS-based antimicrobial polymers with biocide release, non-fouling (i.e., PEG, zwitterions), fouling release (i.e., poly(dimethylsiloxanes), fluorocarbon) and contact killing properties are highlighted. We also report on dual-functional polymers and stimuli-responsive materials. Given the economic and environmental impacts of biofilms in submerged surfaces, we emphasize the importance of less explored QAS-based anti-fouling approaches in the marine industry and in developing efficient membranes for water treatment systems.

Novel metabolite madeirone and neomarinone extracted from Streptomyces aculeoletus as marine antibiofilm and antifouling agents.

Introduction: Biofouling poses a significant economic threat to various marine industries, leading to financial losses that can reach billions of euros annually. This study highlights the urgent need for effective alternatives to traditional antifouling agents, particularly following the global ban on organotin compounds. Material and methods: Streptomyces aculeolatus PTM-346 was isolated from sediment samples on the shores of the Madeira Archipelago, Portugal. The crude extract was fractionated using silica flash chromatography and preparative HPLC, resulting in two isolated marinone compounds: madeirone (1), a novel marinone derivative discovered in this study, and neomarinone (2). The antifouling activities of these compounds were tested against five marine bacterial species and the larvae of the mussel Mytilus galloprovincialis. Additionally, in silico and in vivo environmental toxicity evaluations of madeirone (1) and neomarinone (2) were conducted. Results: Madeirone (1) demonstrated significant antibiofilm efficacy, inhibiting Phaeobacter inhibens by up to 66%, Marinobacter hydrocarbonoclasticus by up to 60%, and Cobetia marina by up to 40%. Neomarinone (2) also exhibited substantial antibiofilm activity, with inhibition rates of up to 41% against P. inhibens, 40% against Pseudo-oceanicola batsensis, 56% against M. hydrocarbonoclasticus, 46% against C. marina, and 40% against Micrococcus luteus. The growth inhibition activity at the same concentrations of these compounds remained below 20% for the respective bacteria, highlighting their effectiveness as potent antibiofilm agents without significantly affecting bacterial viability. Additionally, both compounds showed potent effects against the settlement of Mytilus galloprovincialis larvae, with EC50 values of 1.76 µg/mL and 0.12 µg/mL for compounds (1) and (2), respectively, without impairing the viability of the targeted macrofouling species. In silico toxicity predictions and in vivo toxicity assays both support their potential for further development as antifouling agents. Conclusion: The newly discovered metabolite madeirone (1) and neomarinone (2) effectively inhibit both micro- and macrofouling. This distinct capability sets them apart from existing commercial antifouling agents and positions them as promising candidates for biofouling prevention. Consequently, these compounds represent a viable and environmentally friendly alternative for incorporation into paints, primers, varnishes, and sealants, offering significant advantages over traditional copper-based compounds.

Bridging aquatic invasive species threats across multiple sectors through One Biosecurity.

Understanding the magnitude of biosecurity risks in aquatic environments is increasingly complex and urgent because increasing volumes of international shipping, rising demand for aquaculture products, and growth in the global aquarium trade, are accelerating invasive alien species spread worldwide. These threats are especially pressing amid climate and biodiversity crises. However, global and national biosecurity systems are poorly prepared to respond because of fragmented research and policy environments, that often fail to account for risks across sectors or across stakeholder needs and fail to recognize similarities in the processes underpinning biological invasions. In the present article, we illustrate the complex network of links between biosecurity threats across human, animal, plant, and environment sectors and propose a universal approach to risk assessment. One Biosecurity is a holistic, interdisciplinary approach that minimizes biosecurity risks across human, animal, plant, algal, and ecosystem health and is critical to reduce redundancy and increase cross-sectoral cohesion to improve policy, management, and research in aquatic biosecurity.