Sponges, the oldest metazoans on the planet, have an evolutionary history shaped by symbiotic associations with microorganisms. Although well studied in marine sponges, these associations are poorly understood in freshwater species. This study explored the taxonomic diversity and functional potential of the microbiome of the freshwater sponge Metania sp. and its distinction from the surrounding water, using a metagenomic approach. The samples were collected in the Brazilian Cerrado. Taxonomic assignment identified 17 phyla, including bacterial and archaeal, with 19 sequence variants successfully assigned to the species level. Bacteria comprised 16 phyla, with a predominance of Pseudomonadota, Actinomycetota, and Bacteroidota in both microbiomes. The sponge microbiome is distinct from the water microbiome (PERMANOVA; F = 21.6, p = 0.04), sharing only 27% of the identified taxa. Functional prediction resulted in 7,201 KEGG Orthologs (KOs), assigned to 117 significantly enriched metabolic pathways. Although 95 pathways are shared, differential abundance analysis identified 1,024 KOs more abundant in the sponge microbiome and 1,275 in the water. The presence of bacterial defense systems such as CRISPR-Cas in the sponge microbiome suggests a crucial role in protecting against phages while maintaining symbiosis. In contrast, the water microbiota is enriched with pathways linked to environmental adaptation, such as secondary metabolite biosynthesis and pollutant degradation. Although the water microbiome harbored 1.3 times more biosynthetic gene clusters (BGCs), the sponge microbiome also demonstrated biotechnological potential for producing secondary metabolites, especially antimicrobial. These findings demonstrate that the freshwater sponge Metania sp. hosts a complex and functionally specialized microbial community that plays fundamental roles in adaptation, nutrition, and defense, highlighting the critical importance of symbiotic associations for the host.

Marine sponges (phylum Porifera) are key reef organisms, yet they remain understudied in the western Indian Ocean region. This study provides the first quantitative assessment of sponge assemblages in the bay between Nosy Be island and mainland Madagascar by examining their spatio-temporal diversity patterns and relationship with different substrate types. Photo-quadrat surveys to determine percentage sponge cover and substrate types were conducted annually from 2020 to 2022 at three reef stations (Gorgone, Heloise and Pirogue). The data were analysed with generalised linear models (GLMs), non-metric multidimensional scaling, PERMANOVA, SIMPER and AICc-based model averaging. We identified 26 operational taxonomic units (OTUs), representing 15 families and 10 orders. Sponge cover was low (mean 5.9 ± 0.6% SE) and showed strong spatial differences (GLM, p < 0.001) but limited interannual variation. Pirogue exhibited the highest sponge abundance (4.97 ± 0.6 ind. M2) and taxonomic richness (2.73 ± 0.24 OTU m-2), whereas Gorgone (closest to the coast of Nosy Be) had the lowest values. The sponge assemblages were dominated by a few taxa (e.g. Pseudoceratina sp., Dendroceratida sp. 1, Callyspongia spp. and Amphimedon sp.). Model averaging revealed a positive association between hard coral cover and sponge cover (p = 0.001). These results establish an ecological baseline for reefs at Nosy Be and highlight the need to integrate sponges into reef monitoring and conservation strategies for maintaining Madagascar’s coastal ecosystems.

Siderophores are pivotal ‌‌iron-acquisition biomolecules integral to microbial survival, pathogenicity, and ecology. Elucidating these compounds offers critical insights into the microbial dynamics of marine holobionts and potential therapeutic applications. In this study, we present a culture-independent, data-centric strategy to annotate siderophores from the body mass of three marine sponge species: Dragmacidon reticulatum, Aplysina fulva, and Amphimedon viridis. Utilizing Liquid Chromatography-High Resolution Mass Spectrometry (LC-HRMS) coupled with a custom R-based analytical workflow (XCMS and MetaboAnnotation), we putatively annotated 59 siderophores. We employed a validation pipeline, utilizing iron-adduct calculations [M-2H + Fe]+, [M-H + Fe]2+, [2M-2H + Fe]+, mass accuracy thresholds (<3 ppm), retention time deviation (Coefficient of variation < 2%), and chromatograph peak analysis. According to the Metabolomics Standards Initiative (MSI), these annotations correspond to Level 2 (putatively annotated compounds) because they are based on accurate mass matching without chemical standard confirmation. Notably, iron supplementation during extraction did not significantly alter siderophore detection, suggesting constitutive production or environmental saturation. This workflow bypasses the limitations of traditional cultivation, revealing a diverse landscape of iron-chelating metabolites, including Ferricrocin, Aeruginic acid, and Madurastatin directly within the sponge’s body.

Marine sponges provide bioactive components of interest for bone tissue engineering, particularly biosilica (BS) and spongin (SPG). BS resembles the mineral phase of bone, while SPG, a collagen-like protein, contributes elasticity and biocompatibility. Their combination allows the fabrication of bioinspired scaffolds capable of guiding osteogenesis. In this work, 3D-printed alginate scaffolds were produced with increasing BS content (50-70% w/w) or with BS combined with SPG (35-49% BS, 15-21% SPG). Rheological tests confirmed predominantly elastic behavior in all bioinks, with G' higher than G″ across the linear viscoelastic range. SEM revealed BS spicules evenly distributed within alginate and alginate-SPG matrices, generating integrated fibrous networks. Compression assays showed progressive reinforcement with higher BS content: BS3 (70% BS) reached 6.64 ± 1.19 MPa, while BS-SPG3 (49% BS + 21% SPG) presented the best overall performance (E = 2596.16 ± 257.23 Pa; σu = 12.44 ± 3.77 MPa). Si release increased over 14 days, peaking at 13.87 mg/L for BS3 and 26.43 mg/L for BS-SPG3. Cell assays with MC3T3-E1 confirmed biocompatibility. Migration was favored in BS-rich scaffolds, especially BS3, while BS-SPG remained comparable to the control. ARS staining highlighted stronger mineral deposition in BS3 and BS-SPG3 at days 7 and 14. Gene expression of RUNX-2, OCN, and BSP was upregulated, most markedly in BS3 and BS-SPG3, confirming their osteoinductive character. Together, these results demonstrate that BS-SPG scaffolds combine structural reinforcement, controlled ion release, and biological activity, supporting their potential as sustainable candidates for bone regeneration.

Animals that filter-feed on environmental microbes must rapidly discriminate among captured bacteria to maintain beneficial associations while avoiding inappropriate immune activation. In innate immunity, this discrimination is executed through transcription factors (TFs), whose activation and nuclear translocation initiate effector gene expression and shape the nature of the host response. In sponges, bacteria are first physically captured by choanocytes, but the timing and cellular context in which TF-mediated immune discrimination becomes evident remains unclear. Here, we investigate the earliest detectable regulatory responses associated with discrimination between symbiotic and non-symbiotic bacteria in the marine sponge Amphimedon queenslandica. Using a feeding-based design to model post-metamorphic microbiome restructuring, we exposed juvenile sponges that already harbour vertically inherited symbionts to native (symbiont) or foreign (non-symbiont) bacterial communities and assessed early cellular processing and transcriptional responses to bacterial uptake. Symbiotic bacteria were rapidly transported across the epithelium and induced a strong, transient activation of conserved innate immune TFs, including IRF, NF-κB, and STAT, together with associated signalling pathways. IRF and NF-κB translocated to the nuclei of amoebocytes that had engulfed symbionts, indicating that discrimination becomes evident shortly after uptake and precedes downstream effector responses. In contrast, foreign bacteria were internalized more slowly, failed to induce coordinated immune TF activation or nuclear translocation, and instead elicited a xenobiotic-dominated transcriptional program. Together, these findings identify TF activation as an early regulatory checkpoint in sponge-microbe interactions and reveal key mechanisms that underpin the initial stages of symbiont discrimination.

Sponge-associated bacteria are recognized as prolific sources of bioactive metabolites. Although members of the promising phylum Bacillota are commonly found in marine sponges, their genomic potential remains largely unexplored. This study aims to investigate the Bacillus stercoris 84-5 strain isolated from the sponge Darwinella sp. and evaluate its biosynthetic and enzymatic potential. Whole-genome sequencing and comparative analyses of biosynthetic gene clusters (BGCs) were conducted. In parallel, in vitro assays were performed to evaluate biosurfactant activity (emulsification and surface tension) and enzymatic profiles. The 84-5 genome (4.12 Mbp) encodes at least 11 potential BGCs. In particular, a nonribosomal peptide synthetase (NRPS) cluster showed 82% similarity to a surfactin gene cluster from Bacillus velezensis FZB42, and a corresponding surface tension of 27.44 ± 0.33 mN/m. Genes related to the production of carbohydrate-active enzymes (CAZymes) were also detected. In vitro assays confirmed the production of agarase, alginate lyase, and peptidase, with an enzymatic index (EI) > 3.5 for agarase and peptidase. Comparative analyses revealed shared BGC families among sponge-associated Bacillota genomes. The high diversity of putative bioactive BGCs found, including many shared among sponge-associated Bacillota, suggests biosynthetic pathways that are likely to play important ecological roles within the sponge holobiome. Additionally, the abundance of enzymes probably reflects the metabolic versatility required for life in marine niches. The marine B. stercoris 84-5 exploration thus reveals a promising candidate for exploiting both biosurfactant and enzymatic capabilities, shedding light on the understudied potential of sponge-associated Bacillota.

Pancreatic ductal adenocarcinoma (PDAC) remains a highly lethal malignancy with few therapeutic options. Topoisomerase IIα (TOPO2α) is frequently overexpressed in PDAC and is associated with poor clinical outcomes, yet current TOPO2α-directed therapies are constrained by limited efficacy and toxicity. Barettin, a brominated indole-containing diketopiperazine isolated from the marine sponge Geodia barretti, has not previously been evaluated against PDAC-relevant targets. Here, we identify barettin as a TOPO2α inhibitor using an integrated phenotypic, computational, and biochemical approach. Barettin exerts a cytostatic, non-toxic effect, selectively suppressing proliferation in a subset of PDAC models while showing reduced activity in others, revealing context-dependent efficacy and biological selectivity. Consistent with this, barettin inhibits TOPO2α-mediated DNA decatenation in vitro, demonstrating direct interference with enzyme activity. These findings support barettin as a selective inhibitor of a cancer-relevant proliferative pathway, uncovering a potential vulnerability in a subset of PDAC.

Host-parasite interactions are influenced by both abiotic and biotic factors. While abiotic drivers, particularly temperature, have received considerable attention in recent years due to global climate change, the role of biotic factors remains comparatively underexplored. The malacosporean parasite Tetracapsuloides bryosalmonae (Tb), which causes proliferative kidney disease in salmonids, is a well-documented example, where elevated temperature and eutrophication have been shown to intensify disease prevalence and severity. In this study, we investigated whether freshwater sponges, known for their particle-filtering capabilities, can graze on malacosporean spores in the aquatic environment, potentially acting as biotic filters that may influence parasite transmission dynamics. Using an experimental setup, we employed environmental DNA sampling to (1) characterise the short-term release of Tb spores from infected 1+ brown trout (Salmo trutta) and (2) assess the ability of freshwater sponge (Ephydatia muelleri) to remove Tb spores from water and function as a bio-sampler. Our results show that sponges significantly reduced Tb DNA concentrations in water. However, their effectiveness as bio-samplers and concentrators of Tb was limited, likely due to the rapid degradation of ingested Tb DNA. These results suggest that freshwater sponges may function as natural biological controllers of Tb by filter feeding on its infectious planktonic stages in natural environments.

Sponges (phylum Porifera) are known to form symbiotic relationships with a variety of organisms, including other sponges. Recently, such symbiosis has been described between two homoscleromorph species (Plakortis symbiotica and P. deweerdtaephila) and two representatives of the demosponge order Haplosclerida (Xestospongia deweerdtae and Haliclona plakophila). While studying genomic data from the H. plakophila-P. symbiotica association, we discovered an unusual third mitochondrial genome (mitogenome). Additional sampling conducted for this study revealed that this genome belongs to a new species of Haplosclerida, which we name Metilla boricua gen. nov. sp. nov. Here we describe this new species along with its mitogenome. While M. boricua is superficially similar to H. plakophila, it can be distinguished both by skeletal organization and spicule composition. Its mitogenome is also highly unusual, featuring an elevated GC content and missing the cox2 gene. Phylogenetic analyses based on nuclear 18S and 28S gene sequences place M. boricua into a poorly sampled clade F within the order Haplosclerida. We also report the mitogenome of symbiotic haplosclerid X. deweerdtae, which we sequenced before the new species was identified. Our results support three independent origins of Haplosclerida-Plakortis symbiosis, a finding that redefines the context for future investigation of these relationships.

The rising demand for safe and effective alternatives for bone regeneration has spurred extensive research into biomaterials derived from marine collagen. This systematic review aimed to evaluate the feasibility of marine collagen-based compounds and derived constructs for bone regeneration in in vivo preclinical models while critically assessing the methodological quality of the included studies. The review was conducted following PRISMA guidelines, utilizing the PICO framework to delineate the scope and research focus. After applying predefined inclusion and exclusion criteria, a comprehensive search across multiple databases identified 15 eligible studies. Methodological quality was appraised using the ARRIVE 2.0 guidelines, and the risk of bias was weighed through the SYRCLE tool. The selected studies evaluated collagens derived from fish and marine sponges, which were processed into scaffolds, membranes, and hydrogels. These biomaterials exhibited notable biocompatibility, osteoconductivity, and efficacy in promoting new bone formation. Furthermore, synergistic combinations with hydroxyapatite, chitosan, and growth factors such as BMP-2 significantly enhanced their regenerative capacity. However, several critical shortcomings were observed in experimental designs, including inadequate randomization, absence of blinding, and insufficient reporting of animal handling protocols. These limitations raise concerns regarding reproducibility and the overall validity of the findings. In conclusion, marine collagen-based biomaterials hold significant potential for bone regeneration applications. Nevertheless, achieving greater standardization and methodological rigor in preclinical research is paramount to ensuring their successful clinical translation.

Inhibition of PTCH1 drug efflux activity enhances chemotherapy efficacy against triple negative breast cancers.

Symbiotic relationships between microbes and hosts frequently involve the assembly of complex microbial communities. Community-level patterns influence life-history traits, ecological trajectories of partners, and are often critical for host health. These patterns are driven by mechanisms acting at the individual level, including microbial dispersal, host selection, and microbe-resource interactions. Critically, we still lack a clear picture of how these mechanisms interact to shape microbiome assembly. We present a model that describes how distinct community structures arise from those underlying mechanisms. To illustrate the approach, we simulate microbiome data from marine sponges, thereby bridging mechanistic models and empirical patterns. We further apply the model to human data to explore its relevance across systems, proposing that a small set of general mechanisms may govern diverse patterns of diversity and abundance. Our findings advance ecological theory by linking individual-level processes to community-scale patterns, illuminating key drivers of microbiome assembly.

Pyridinium alkaloids - a unique class of naturally occurring salt-form secondary metabolites: a comprehensive review of 68 years (1958-mid-2025).

Marine-derived products exhibit applicability in the field of biomaterials and medical devices due to their unique physical, chemical, and biological properties including mechanical reinforcement, underwater adhesion, swelling capacity, and biocompatibility. They can support crucial cellular proliferation, migration, and differentiation, being suitable for tissue engineering and wound healing. This review discusses biomaterials and medical devices derived from marine sources by analyzing their natural properties and highlighting advantages of scaffolds, adhesives, and drug delivery systems. We review organisms from the animal phyla Porifera (sponges), Cnidaria (jellyfish, corals), Mollusca (molluscs, octopus), Chordata (fish, sea squirt), algae phylum Chlorophyta (green microalgae), and prokaryotic phylum Cyanobacteria (cyanobacteria). We discuss the need of applying suitable controls and establishing a sustainable scale-up process to assess their promising results and make them available for patients. We also highlight the advantage of implementing biotechnology and waste by-products in their crafting as an opportunity for incorporating biomedicine in a circular economy.

Objectives Marine sponges, such as Dactylospongia metachromia and Suberites aff. clavatus from the Red Sea have emerged as potential sources of bioactive compounds with significant antimicrobial properties. Methods This study investigates the antibacterial and antibiofilm activities of methanol–dichloromethane extracts from these sponges against clinically relevant strains of Gram-positive bacteria, including Staphylococcus aureus , Methicillin-resistant Staphylococcus aureus , and Staphylococcus epidermidis , as well as Gram-negative pathogens like Pseudomonas aeruginosa and Escherichia coli using agar well diffusion, broth microdilution, biofilm inhibition/eradication assays, scanning electron microscopy (SEM), and LC-MS profiling. Results The results revealed that the extract of Dactylospongia metachromia exhibited promising antibacterial activity, particularly against Gram-positive strains, with a significant zone of inhibition and moderate bactericidal effects, indicated by MICs of 250 µg/mL for both Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus . In contrast, Suberites aff. clavatus showed minimal antibacterial activity. Additionally, Dactylospongia metachromia demonstrated effective inhibition and eradication of biofilm formation, particularly against Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus . Scanning electron microscope images further revealed rupture of the bacterial membrane. LC-MS tentatively identified smenospongine as a major antibacterial component, while metachromin H and nakijiquinone J showed no reported antimicrobial activity. Suberites aff. clavatus showed minimal activity. Conclusion These findings suggest that Dactylospongia metachromia could be a valuable source for developing new treatments for skin infections caused by antibiotic-resistant bacteria, while Suberites aff. clavatus may require further exploration for its bioactive compounds. This study highlights the therapeutic potential of Red Sea sponges and supports the need for continued research into marine natural products for antimicrobial drug development.

An amphibious Amazon freshwater sponge: Cauxi

This study explores the cytotoxic efficacy of combining Dysidea tuapokere or Agelas conifera extract with silver nanoparticles (AgNPs) synthesized from Aspergillus flavus on various cancer cell lines and pathogenic bacteria. AgNPs were characterized using zeta potential, dynamic light scattering, and scanning electron microscopy. The chemical composition of the marine sponge extracts was analyzed using LC-MS/MS. Cancer cell lines (PANC-1, A549, MCF-7, and HT-29) and normal HUVEC cells were tested for cytotoxicity using MTT assays to calculate selectivity indices (SI). Antibacterial activity was assessed against antibiotic-resistant strains. Docking studies were conducted to investigate the binding of sponge-derived compounds to EGFR and TrkA receptors. Characterization of AgNPs revealed a mean particle size of 69.455 nm, a zeta potential of -28 mV, and a polydispersity index (PDI) of 0.177. After lyophilization, the particle size increased to 144.555 nm and the PDI to 0.335. SEM showed silver particles below 0.5 μm. Combining Dysidea tuapokere or Agelas conifera extracts with AgNPs enhanced antiproliferative activity. This activity was relatively selective for cancer cells over HUVEC cells, particularly for PANC-1 (SI: 254.74) and A549 (SI: 204.85). LC-MS/MS identified bioactive components. Docking showed favorable binding to EGFR and TrkA. Dysidea tuapokere extract with AgNPs significantly enhanced the inhibition of S. xylosus, K. oxytoca, and P. aeruginosa. The synergistic antiproliferative effect selectively targets cancer cells. The combined treatment may have broad-spectrum bioactivity. This study highlights the synergistic potential of marine sponge extracts combined with AgNPs.

Sterols are a class of lipids that play a crucial role in human health through their essential physiological roles and as a point of interaction between commensal and pathogenic bacteria. The biosynthesis and modification of these lipids is a well-characterized process in many eukaryotes and increasingly in bacteria. However, the proteins responsible for formation of the unusual 8(14)-unsaturation found in the sterols produced by aerobic methanotrophs, dinoflagellates, nematodes, and marine sponges, remains unknown. Here, we utilize a heterologous expression system to identify a bacterial 8,14-sterol reductase (8,14-Bsr) responsible for generating the 8(14)-unsaturation in the aerobic methanotroph Methylococcus capsulatus. This enzyme modifies the direct product of C-14 demethylation, reducing one double bond in the nuclear core structure and isomerizing the other to produce an 8(14)-sterol. We subsequently tested the requirement of putative active site residues for catalysis through site directed mutagenesis, identifying residues likely involved in interacting with the sterol substrate and directly catalyzing this reaction. Bioinformatic analysis of the distribution of 8,14-Bsr reveals it is unique to the bacterial domain, found primarily in the Methylococcaceae family, the Mycobacteriales order, and yet uncultured members of the Myxococcota phylum. Further phylogenetic analysis of 8,14-Bsr suggests it shares an evolutionary history with the C-14 demethylase in these organisms and that these two enzymes were likely inherited together. These results provide insight into novel sterol biochemistry, further delimiting sterol biosynthesis in the bacterial domain from eukaryotes and illustrating the importance of molecular characterization to identify bacterial proteins that interact with sterols.IMPORTANCEMany of the eukaryotic proteins required for the biosynthesis of sterols, such as cholesterol, have been characterized. However, the pathways governing analogous processes in the bacterial domain are less characterized. Here, we identify an 8,14-sterol reductase in aerobic methanotrophs. This enzyme carries out a unique biochemical reaction, saturating and isomerizing double bonds in the nuclear core structure to produce an 8(14)-sterol. This reductase is restricted to the bacterial domain, further separating the evolution of bacterial sterol production from eukaryotes. Additionally, we find this reductase is prevalent in members of the sterol degrading order Mycobacteriales, highlighting a potential role for this protein in the remodeling of host sterol production by these pathogens.

Marine natural products, including seaweeds, sponges, and marine microorganisms, have emerged as promising sources of bioactive compounds with diverse pharmacological properties. We investigated the antibacterial and antioxidant potential of ethanol extracts (30%, 60%, and 90%) from Saccharina japonica collected from two Korean coastal regions, Gijang and Wando, and evaluated their bioactive metabolites through integrated in vitro and in silico approaches. Among the extracts, the 60% ethanol fraction exhibited the highest total phenolic content and strongest 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity, indicating superior antioxidant capacity. Antibacterial assays revealed selective concentration-dependent inhibition against Staphylococcus aureus, while limited effects were observed against Escherichia coli. Kinetic analysis further demonstrated growth suppression of S. aureus at higher concentrations. Molecular docking was performed against multiple bacterial proteins, including DNA gyrase, topoisomerase IV, and tyrosyl-tRNA synthetase. Sterol compounds, particularly fucosterol and 24-methylene cholesterol, showed strong binding affinities across key targets, suggesting their potential role as multitarget antibacterial agents. ADMET predictions indicated favorable pharmacokinetic properties, although high lipophilicity and potential hERG II inhibition were noted. Overall, while the antibacterial effects observed were moderate, these findings suggest that marine-derived sterols from S. japonica may represent compounds of interest for further mechanistic investigation and optimization in complementary antibacterial strategies.

Manzamine-A (MA), a complex β-carboline alkaloid isolated from various genera of marine sponges, has attracted significant attention due to its unique structure and broad spectrum of potent biological activities. Despite the therapeutic potential, its development is limited by challenging natural supply and suboptimal pharmacokinetics. To address these barriers, innovative total syntheses of its intricate polycyclic framework have been achieved, enabling the development of semi-synthetic and synthetic analogues aimed at improving potency and drug-like properties. This review comprehensively outlines the progress in understanding this marine natural product, mainly focusing on its microbial origin, biological activities, pharmacokinetic behavior, chemical synthesis, and derivatives' and analogues' development. By integrating these diverse yet interconnected fields of research, this review bridges the critical gap between the natural product's discovery and its clinical translation. Additionally, it also provides a roadmap for future drug development, highlighting how interdisciplinary collaboration can unlock the therapeutic potential of MA as a viable clinical candidate.