Search Results (80)

Tenacibaculum maritimum is a major etiological agent of tenacibaculosis in marine fish and represents an increasing concern for Chilean salmon aquaculture; however, updated information on the phenotypic and molecular diversity of circulating isolates is limited. This study characterized 40 isolates recovered from Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss), and red cusk eel (Genypterus chilensis) obtained from outbreaks between 2020 and 2024. Isolates were analyzed using biochemical and phenotypic assays, multiplex PCR targeting the O-antigen gene cluster (O-AGC), REP-PCR-based genetic fingerprinting, and experimental bath challenges in Atlantic salmon. Phenotypic characterization revealed species-consistent traits but variable gelatin and starch hydrolysis and differences in seawater tolerance. O-AGC typing identified four molecular serotypes (1-0, 3-1, 3-2, and 4-0), with serotypes 1-0 and 3-2 detected for the first time in Chilean salmonids. Genetic fingerprinting distinguished previously described profiles and two novel REP patterns (REP6 and REP7), indicating additional genomic heterogeneity within dominant serotypes. Virulence assays showed cumulative mortality ranging from 0% to 100%, with serotype 3-1 isolates generally associated with higher mortality and serotype 4-0 displaying broad intra-serotype variability. These findings document substantial phenotypic, antigenic, and genetic diversity among Chilean T. maritimum isolates and provide epidemiologically relevant information for disease surveillance and vaccine design in salmon aquaculture. Full article

Gelatin is a valuable hydrocolloid produced by partial hydrolysis of collagen from mainly mammalian and fish sources. The rheological properties of fish gelatin differ from those of mammalian species in terms of gel strength, viscosity, and other rheological characteristics, even from different fish species and parts of the fish with different properties. Fish gelatin is sustainable for the environment and easy for people to accept for cultural reasons. Owing to these properties, gelatin is used across food, biomedical, pharmaceutical, and health sectors, where 3D printing enables customization and functional performance. Key determinants of print fidelity include gelatin concentration, rheological properties, temperature, gelling behavior, water content, and printing parameters. Suitability for 3D printing is typically assessed via physicochemical characterization, particularly rheology and gelling mechanisms/kinetics. Gelatin-based 3D printing systems offer various advantages due to their biocompatibility, low cost, and controllable rheological properties, and they have potential applications in the food, healthcare, biomedical, tissue engineering, and drug delivery system areas. Using gelatin in combination with other additives can improve printing accuracy and mechanical strength parameters, overcome the limitations of gelatin’s inherent mechanical strength, and develop higher printing accuracy and performance systems. This allows for the development of functional, innovative, and high-value-added products while ensuring safe use. Full article

This work reports on the synthesis and electrochemical investigation of sustainable carbon–TiO₂ nanocomposites derived from marine biowaste, designed to elucidate light-assisted charge storage mechanisms in non-aqueous electrolytes. Porous carbons obtained from prawn chitin and blue shark gelatin were decorated in situ with TiO₂ nanoparticles using a deep eutectic solvent (DES) as a green synthesis medium. Structural and morphological characterisation revealed that TiO₂ incorporation induces significant nanoscale reorganisation of the carbon framework, resulting in hierarchical porosity, increased surface area, and intimate semiconductor–carbon interfaces. Electrochemical evaluation in a three-electrode configuration using an ethaline-based DES electrolyte demonstrated that TiO₂ decoration substantially enhances capacitive performance and cycling stability, with the prawn chitin-derived composite achieving a specific capacitance of 54 ± 3 F g⁻¹ and 91% retention after 10,000 cycles. Under illumination, all TiO₂-containing composites exhibited a pronounced increase in anodic current response and discharge time, indicating photo-assisted surface charge accumulation. Although the absolute capacitance values are modest compared to those of aqueous supercapacitor systems, the results provide mechanistic insight into the interplay among nanostructure, semiconductor photoactivity, and ion transport in viscous, hydrogen-bonded DES electrolytes. By combining waste-derived carbons, green synthesis routes, and photo-responsive nanostructures, this study highlights a sustainable strategy for developing multifunctional carbon-based nanomaterials with light-modulated electrochemical behaviour. Full article

Global demand for sustainable food packaging materials has intensified research on bio-based biopolymer systems capable of delivering functional compounds. Among these, protein–polysaccharide gels have emerged as versatile matrices for the incorporation and controlled release of antioxidant and antimicrobial agents. This review examines recent advances in the design and functionality of protein–polysaccharide gel systems for active food packaging applications. Particular attention is given to representative hybrid matrices such as casein/chitosan, gelatin/alginate, and whey protein/pectin systems, highlighting their gelation mechanisms, molecular interactions, and physicochemical properties. Furthermore, the review explores the potential of agro-industrial and marine by-products as renewable sources of proteins, polysaccharides, and bioactive compounds within circular bioeconomy strategies. Current limitations related to stability, scalability, and regulatory compliance are also addressed. By integrating structural, functional, and sustainability perspectives, this work provides a comprehensive framework for the development of next-generation protein–polysaccharide gel carriers for active food packaging. Full article

Marine byproducts generated from seafood processing represent valuable reservoirs of structurally and functionally distinct biomolecules, whose composition reflects species, habitat, and processing history. This systematic review identified which marine byproducts have been most extensively studied between 2020 and 2025, with emphasis on their composition, valorisation, and suitability for tracing their geographic origin. Following the PRISMA protocol, 6443 publications were initially retrieved, of which 96 peer-reviewed studies were included for data extraction and analysis. The five most frequently investigated byproducts—skin, bones, scales, shells, and roe—were identified as rich sources of proteins (collagen and gelatin), minerals (hydroxyapatite and calcium carbonate), polysaccharides (chitin), lipids (notably polyunsaturated fatty acids (PUFAs), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA)), and vitamin B12. Collagen properties, particularly imino acid content, hydroxylation degree, crosslinking density, and thermal stability, correlate more strongly with environmental temperature than taxonomy, supporting their potential as markers for tracing geographic origin. The mineral fractions, dominated by hydroxyapatite in bones and scales, or calcium carbonate in shells, provided complementary inorganic fingerprints based on calcium-to-phosphorus ratios, carbonate substitution, trace element composition, and thermal analyses. While the lipid profile alone could not completely discriminate fish roe, proteomic techniques, such as MALDI-TOF MS, make it possible to reliably identify species. Collectively, these byproducts offer complementary organic and inorganic markers that support integrated strategies that allow tracing their origin and fostering their sustainable valorisation, overcoming a key technical bottleneck for their use. However, their large-scale conversion into market-ready products remains limited by technical complexity, process variability, and cost-related constraints. Full article

With in situ imaging systems becoming more common, precise, and economically viable, use of these systems has grown dramatically, including both automated classification and biomass estimations. However, a rather large and overlooked portion of these efforts is reliable detection and classification of these organisms as they pass through the imaging device. This paper focuses on the development of an end-to-end classification CNN-based algorithm for marine zooplankton using the in situ Ichthyoplankton Imaging System (ISIIS-DPI) from Bellamare (La Jolla, CA, USA). Our novel approach considers many issues with automated segmentation and classification, including over-segmentation, noise segmentation, and organism size input. This allows for classifications in diverse water types, demonstrated by the comparison of three datasets created in conjunction with this project, each with very different water properties and zooplankton communities (Florida Gulf coast; Trondheimsfjord, Norway; Sargasso Sea). Our segmented image dataset contains 70,624 regions of interest (ROIs) across four organism classes—Chaetognath, Crustacean, Gelatinous, and Larvacean—with two classes dedicated to detritus. Four common network architectures—Resnet, Xception, GoogleNet, and Darknet—are trained on this dataset, with final test accuracies in the range of 95.94–96.09%. Following this initial training, a secondary level of classification is introduced. The base Gelatinous class is further divided into six groups. The same four CNN architectures are used once again, with final accuracies in the range of 86.12–90.40%, showing the ability to taxonomically classify down to the order level. The present work introduces a versatile, adaptable, scalable and autonomous segmentation and classification algorithm using niched networks mirroring taxonomy, and is fully contained in a publicly available MATLAB R2025a custom graphical user interface. Full article

Agricultural and agro-industrial residues are increasingly recognized as sustainable, low-cost feedstocks for high-performance biomedical materials. This review critically examines the translational potential of polysaccharides, proteins, inorganic compounds, and phytochemical-rich extracts derived from agro-waste, highlighting their chemical features, structure–function relationships, and application-specific readiness. Polysaccharides such as nanocellulose, pectin, and chitosan emerge as the most advanced biopolymer platforms, particularly in wound healing, drug delivery, and 3D-printed scaffolds. Protein-derived materials—including collagen, gelatin, keratin, and soy protein—show strong promise in regenerative medicine, though challenges in mechanical stability and batch reproducibility remain. Inorganic phases such as hydroxyapatite and silica obtained from eggshells, rice husk ash, and marine shells demonstrate high bioactivity, with dental and bone applications approaching clinical translation. Finally, fruit-residue phytochemicals provide multifunctional antioxidant and antimicrobial enhancements to composite systems. By integrating material chemistry, processing strategies, and translational considerations, this review outlines the current state, challenges, and future perspectives for advancing agro-waste-derived biomaterials within a circular bioeconomy. Full article

The need for sustainable alternatives to petroleum-based plastic packaging has prompted interest in biodegradable biopolymer films. This study developed edible composite films using minimally refined chitosan from American lobster (Homarus americanus) shell waste combined with fish gelatin, glycerol, and sunflower oil. A Box–Behnken design within a response surface methodology (RSM) framework was used to investigate the effects of these formulation variables on ten key film properties, including mechanical strength, water sensitivity, barrier performance, and optical characteristics. High-quality empirical models (R² ≥ 0.88) captured nonlinear, synergistic, and antagonistic interactions among the components, revealing trade-offs between competing attributes. Simultaneous multi-response optimization identified balanced formulations suited to various food packaging needs, including perishable, fresh, and dry products. Experimental validation of selected formulations confirmed model predictions within 5% error under laboratory conditions. Up to 68% of the inhibition activity against Escherichia coli was retained in a few composite formulations when compared with neat chitosan films, thus supporting their potential for active packaging. The key highlight of the present work is the use of crude chitosan derived from lobster shell waste, a low-cost, sustainable alternative to highly purified commercial sources, demonstrating the practical viability of marine byproduct valorization. Overall, this study advances the development of high-performance, application-specific biopolymer films and highlights RSM as an effective tool for optimizing multifunctional edible packaging materials. Future work should focus on enhancing antimicrobial functionality, evaluating real-world performance, and assessing consumer acceptance to support industrial adoption. Full article

Gene editing technologies such as CRISPR/Cas9 have revolutionized functional genomics, yet their application in marine fish cell lines remains limited by inefficient delivery. This study compares three delivery strategies—electroporation, lipid nanoparticles (LNPs), and magnetofection using gelatin-coated superparamagnetic iron oxide nanoparticles (SPIONs)—for CRISPR/Cas9-mediated editing of the ifi27l2a gene in DLB-1 and SaB-1 cell lines. We evaluated transfection and editing efficiency, intracellular Cas9 localization, and genomic stability of the target locus. Electroporation achieved up to 95% editing in SaB-1 under optimized conditions, but only 30% in DLB-1, which exhibited locus-specific genomic rearrangements. Diversa LNPs enabled intracellular delivery and moderate editing (~25%) in DLB-1 but yielded only minimal editing in SaB-1, while SPION-based magnetofection resulted in efficient uptake but no detectable editing, highlighting post-entry barriers. Confocal imaging and fluorescence correlation spectroscopy suggested that nuclear localization and Cas9 aggregation may influence editing success, highlighting the importance of intracellular trafficking in CRISPR/Cas9 delivery. Our findings demonstrate that CRISPR/Cas9 delivery efficiency is cell line-dependent and governed by intracellular trafficking and genomic integrity. These insights provide a practical framework for optimizing gene editing in marine teleosts, advancing both basic research and selective breeding in aquaculture. Full article

Electrospinning is a versatile technique used to manufacture nanofibers by applying an electric field to a polymer solution. This method has gained significant interest in the biomedical, pharmaceutical, and materials engineering fields due to its ability to produce porous structures with a high specific surface area, making it ideal for applications such as wound dressings, controlled drug delivery systems, and tissue engineering. The materials used in electrospinning play a crucial role in determining the final properties of the obtained nonwoven nanofibers. Among the most studied substances are chitosan, collagen, and fish-derived gelatin, which are biopolymers with high biocompatibility. These materials are especially used in the medical and pharmaceutical fields due to their bioactive properties. In combination with synthetic polymers such as polyethylene glycol (PEG) and polyvinyl alcohol (PVA), these biopolymers can form electrospun fibers with improved mechanical characteristics and enhanced structural stability. The characterization of these materials was performed using modern characterization techniques, such as one-dimensional (1D) proton NMR spectroscopy (¹H), for which the spin–spin relaxation time distributions T₂ were characterized. Additionally, two-dimensional (2D) measurements were conducted, for which EXSY T₂-T₂ and COSY T₁-T₂ exchange maps were obtained. The characterization was complemented with FT-IR spectra measurements, and the nanofiber morphology was observed using SEM. As a novelty, machine learning methods, including artificial neural networks (ANNs), were applied to characterize the local structural order of the produced nanofibers. In this study, it was shown that the nanofiber nonwoven materials made from PVA are characterized by a degree of order in the range of 0.27 to 0.61, which are more ordered than the nanofibers made from chitosan and fish gelatin, characterized by an order degree ranging from 0.051 to 0.312, where 0 represents the completely unordered network and 1 a fully ordered fabric. Full article

Marine Bacteroidota are recognized bacterial producers of bioactive metabolites, yet their biosynthetic potential remains cryptic under standard laboratory conditions. Here, we developed chemically defined media for Fulvivirga kasyanovii 48LL (Cytophagia) and Tenacibaculum mesophilum fLL (Flavobacteriia) to evaluate the effect of environmentally relevant carbon sources on growth and secondary metabolism. F. kasyanovii utilized 31 of 34 tested carbon sources whereas T. mesophilum grew on only five substrates, underscoring a distinct nutritional preferences. Substrate significantly influenced the antibacterial activity of F. kasyanovii extracts. Growth on β-1,3-glucan, glycerol, poly(β-hydroxybutyrate) (PHB), fish gelatin, or pectin resulted in extracts generating the largest inhibition zones (10–13 mm) against Bacillus subtilis or Rossellomorea marisflavi. Genome analysis revealed F. kasyanovii to be enriched in biosynthetic gene clusters (BGCs), notably harboring a ~570 kb genomic island comprising five large NRPS/PKS-type clusters. Quantitative PCR confirmed carbon-source-dependent regulation of these operons: glucose induced BGC1, BGC3, and BGC4, while κ-carrageenan and PHB upregulated BGC2. Conversely, yeast–peptone medium (analogous to standard marine broth) repressed transcription across all active clusters. These findings demonstrate that naturally occurring carbon sources can selectively activate cryptic BGCs and modulate antibacterial activity in F. kasyanovii, suggesting that similar strategy can be used for natural-product discovery in marine Bacteroidota. Full article

Phytoplankton–mesozooplankton interactions play a central role in shaping Black Sea food web dynamics, yet their trophic coupling has been insufficiently investigated in policy-relevant frameworks. This systematic review of 86 peer-reviewed studies (1987–2025) synthesizes research trends, limitations, and knowledge gaps in the field. The analysis reveals a clear dominance of work on plankton community structure (81%), whereas topics such as modeling and scenario analysis (7%), ecosystem assessment (7%), and bloom dynamics and seasonality (5%) remain comparatively underrepresented. Post-2020 publications indicate a promising shift toward scenario-based frameworks, gelatinous zooplankton impacts, and trait-based indicators, although functional integration remains fragmented. Keyword co-occurrence and network analyses revealed a concentration on nutrient–phytoplankton–zooplankton pathways, while other themes—such as bioluminescence and redoxcline dynamics—appeared only marginally represented in the literature we analyzed. To support ecosystem-based management under the Marine Strategy Framework Directive (MSFD), we highlight three priorities: improving NPZD-type models, using trophic efficiency metrics, and standardizing plankton indicators across the region. Strengthening the mechanistic understanding of planktonic trophic linkages is critical for improving food web assessments and adaptive marine governance in the Black Sea. Full article

Collagen is a structural protein found in the connective tissues of terrestrial and marine animals. Its diverse functional attributes span its applications in several industries, including food, supplements, cosmetics, and pharmaceuticals. Typically derived from mammalian sources, collagen and its derivatives, including gelatin and collagen peptides, are essential for the food and supplement industries. Recently, marine collagen has emerged as a viable mammalian collagen alternative due to its unique functionality and sustainability. Marine vertebrates and invertebrates are reliable sources of marine collagen. Some marine organisms are promising sustainable sources of collagen for nutritional applications. Recent research highlights significant advances in marine collagen extraction, processing, and novel applications. Hence, recent interest has propelled research in identifying novel collagen sources and advancing technologies to produce marine collagen-based products. Considering the recent scientific interest in marine collagen, this review provides an overview of recent progress in marine collagen production, including novel sources, innovative processing technologies, nutritional and functional properties, safety and quality control, current challenges, and future research directions. The review highlights certain challenges, including unpleasant odor, flavor, color, insufficient supply, and inconsistent quality of marine collagen. Future research should focus on increasing the collagen extraction yield, improving the smell and flavor, and developing novel delivery systems to increase bioavailability and functionality. Full article

In this study, we investigate the diversity and spatiotemporal distribution of gelatinous zooplankton (GZ) in the central Baltic Sea (coastal waters of Gotland and adjacent Eastern and Western Gotland Basins), a region characterised by low salinity and ecological sensitivity. Despite the Baltic Sea being the largest brackish water body globally, knowledge about its GZ, specifically, medusae and ctenophores, is limited. Our research synthesises the existing literature, open-access data, and local reports. Three to five GZ species occur within the studied area, with the common jellyfish Aurelia aurita dominating. Peak sightings of A. aurita happen between July and October, whereas the ctenophore Mertensia ovum and scyphozoan Cyanea capillata display sporadic occurrences. We identify notable gaps in understanding GZ phenology and food web impacts due to historical neglect and insufficient monitoring, particularly under low-salinity conditions (between 5 and 8), which restricts species richness. Jellyfish and ctenophores fall under the Essential Ocean Variable (EOV) “Zooplankton Biomass and Diversity” governed by the Global Ocean Observing System, UNESCO-IOC. EOVs are an approach for globally usable data and adhere to Findable, Accessible, Interoperable, and Reusable (FAIR) data principles. Including EOVs in routine collection and reporting would significantly enhance regional and global understanding, contributing to a holistic ecosystem view. Thus, we advocate for global ocean observation frameworks to comprehensively monitor GZ populations and their ecological, biogeochemical, and socioeconomic roles. Our findings serve as a crucial step towards understanding the implications of climate change for GZ assemblages in the Baltic Sea, promoting a holistic approach to marine ecosystem management. Full article

Background: Red macroalgal flour resulting from commercial phycocolloid extraction has been shown to include valuable preservative compounds. Methods: This study focused on the preservative effect of a gelatin-based packaging system including Gelidium sp. flour during refrigerated storage of Trachurus trachurus fillets. Different microbial and chemical indices related to quality loss were determined in fish muscle during a 6-day storage period at 4 °C. Results: Compared with gelatin-packaged control samples, those packaged in the system including the algal flour presented significantly lower microbial development (aerobic bacteria, psychrotrophic bacteria, and proteolytic bacteria) and significantly lower chemical indices related to microbial development (pH and trimethylamine). With respect to lipid oxidation, there was significantly greater retention of peroxides and significantly lower formation of secondary oxidation products in the samples packaged with the algal flour. Additionally, the algal flour group presented significantly less lipid hydrolysis. Conclusions: A preservative effect was derived from the addition of Gelidium flour to a gelatin-based packaging system during refrigerated storage of T. trachurus. This study supports the practical and valuable use of Gelidium sp. flour and addresses the current global interest in natural sources of preservative compounds and the use of marine byproducts. Full article