Search Results (112)

The identification and development of novel antimicrobials is a crucial challenge in the face of increasing antibiotic and antimycotic resistance. As such, there is growing interest in exploring the chemical diversity of natural sources, such as invasive seaweeds such as Asparagopsis armata. The valorization of such sources can further contribute to the development of bio-based industries, aligning with societal goals for environmental and economic sustainability. Therefore, a solid-liquid extraction method was performed using ethanol, and the obtained extract was studied for chemical composition elucidation, bioactivity, and toxicity evaluation. Analysis by GC-MS revealed some major chromatographic peaks, including floridoside (2-α-O-D-galactopyranosyl glycerol), glycerol, and oleamide. Also, several other smaller peaks were tentatively attributed to Low Molecular Weight Carbohydrate Derivatives, including isosaccharino-1,4-lactone, which had only been reported once in nature. The extract demonstrated significant antioxidant activity as measured by Ferric Reducing Antioxidant Potential and Oxygen Radical Absorption Capacity, but not by Lipid Peroxidation Inhibitory Potential assays, which is in line with its polar nature. The extract exhibited antimicrobial activity against various microorganisms, with a MIC of 2 mg/mL observed for Staphylococcus epidermidis, Vibrio parahaemolyticus, and the three yeast strains tested. Moreover, the extract inhibited the growth and phenotypic changes in filamentous fungi, which may result in reduced virulence. Specifically, the extract inhibited sporulation in Aspergillus fumigatus and orange pigmentation in Fusarium graminearum, possibly by a reduction in the production of aurofusarin, rubrofusarin, and mycotoxins. In vitro cell viability assays in 3T3, RAW264.7, and HaCaT demonstrated the extract was not cytotoxic or presented low cytotoxicity at concentrations up to 0.1 mg/mL, but a strong cytotoxic effect was observed at 1 mg/mL. At non-cytotoxic concentrations, the ethanol extract inhibited up to 48% of NO production in LPS-stimulated RAW264.7. This may indicate that anti-inflammatory activity may add to the antimicrobial activity in human and animal systemic and topical applications of the extract. In this work, new molecules were reported in A. armata, and the bioactivities reported were novel for this extract and algal species—especially through the choice of uncommon but very relevant pathogens to study. Our findings are a valuable contribution to addressing challenges in human and animal health, food and feed technology, as well as animal husbandry and agriculture. Full article

Antimicrobial resistance (AMR) poses a major global threat to human health. Among multidrug-resistant pathogens, MRSA is a leading cause of severe nosocomial infections, urgently demanding the discovery of novel antimicrobial agents. Nature, particularly Actinomycetota, remains a prolific source of potent bioactive compounds to combat pathogens. This review analyzes recent advancements in anti-MRSA compounds from Actinomycetota. We highlight the most promising bioactive metabolites, their sources, mechanisms of action, and current limitations. Our analysis identified numerous compounds with potent activity against MRSA, including chromomycins, actinomycins, diperamycin, lunaemycin A, lactoquinomycin A, and weddellamycin, which exhibit submicromolar minimal inhibitory concentrations (MICs). The renewed interest in exploring Actinomycetota de novo is directly driven by the AMR crisis. Furthermore, bioprospecting efforts in underexplored ecological niches, such as mangroves and marine sediments, have proven highly promising, as these habitats often harbour unique microbial communities producing novel metabolites. These findings underscore the critical importance of ecology-driven drug discovery in expanding the antimicrobial arsenal and effectively addressing the global health challenge of MRSA and other resistant pathogens. Full article

Marine diatoms are prolific producers of bioactive metabolites, but Arctic species remain underexplored as sources of antibacterial and antibiofilm agents. Here, seven species were grown in photobioreactors (PBRs) and systematically screened for antibacterial, antibiofilm, and cytotoxic activities. All strains inhibited Gram-positive bacteria, and four reduced Staphylococcus epidermidis biofilm formation. Porosira glacialis emerged as a lead species, combining potent antibiofilm activity with favourable traits for large-scale cultivation, and no detectable cytotoxicity. Bioactivity-guided fractionation of P. glacialis yielded two antibiofilm compounds: methyl 3-hydroxyoctadecanoate, the first time reported in diatoms and newly associated with antibiofilm bioactivity, and pheophorbide a, a chlorophyll degradation product. Both inhibited S. epidermidis biofilm formation without any observed cytotoxicity. Notably, Cylindrotheca closterium exhibited cultivation-dependent antibiofilm activity, underscoring the importance of growth conditions for metabolite production. These findings highlight the potential of Arctic diatoms as a sustainable source of antibiofilm agents and support further exploration of their metabolites for antimicrobial and industrial applications. Full article

Marine biotechnology is an emerging field of research. There is scientific evidence of the strong potential of a multitude of marine microorganisms in biotechnology, with applications spanning the medical, pharmaceutical, cosmeceutical, nutraceutical and environmental recovery fields. However, despite the discovery of new natural compounds being of wide-ranging benefit, their practical application still remains difficult due to costs and lengthy validation processes. The strength of natural compounds is that, unlike synthetic or already-known compounds, they can have more specific functions and are generally environmentally friendly. This requires, however, that each newly discovered compound be assayed for its toxicity through tests on model cells and organisms. Research should therefore not stop with the simple discovery of new compounds but go beyond with the validation of their efficacy and safety, an issue that remains poorly addressed for products of marine bacterial origin. This review analyses current knowledge on natural compounds of marine bacterial origin, trying to focus on the necessary steps after their discovery, including the investigation of their non-toxicity to model organisms. Full article

Macroalgae are valuable natural sources for bioprospection and the development of raw materials applicable to the nutrition, health, and agriculture industries. To build a basis for the sustainable use of marine organisms from the Colombian Caribbean, a preliminary study was conducted focusing on known functional compounds in two genera of macroalgae, including the species Acanthophora spicifera (Rhodophyta), Sargassum ramifolium, and Sargassum fluitans (Ochrophyta). This study included the extraction and identification of polysaccharides using ultrafiltration, nuclear magnetic resonance (¹H-NMR), Fourier-transform infrared spectroscopy (FT-IR), and size exclusion chromatography (SEC); fatty acids by gas chromatographic (GC) profiling; and phenolic composition and antioxidant activity by complementary semi-quantitative methods (ABTS, DPPH, FRAP, and ORAC assays). Carrageenan-type polysaccharides were detected in A. spicifera, while alginate and fucoidan types were found in S. ramifolium and S. fluitans; palmitic acid was the predominant fatty acid in A. spicifera and S. ramifolium, but it was not detected in S. fluitans. S. ramifolium showed the highest ABTS, DPPH, and ORAC activities and phenolic compounds, while S. fluitans exhibited the highest FRAP activity. This study contributes to the chemical knowledge on Colombian macroalgae to establish potential applications in various fields, including biomedicine, cosmetics, functional foods, and nutraceutical ingredients. Full article

The Red Sea is rich in symbiotic microorganisms that have been identified as sources of bioactive compounds with antimicrobial, antifungal, and antioxidant properties. In this study, we aimed to explore the potential of marine sponge-associated bacteria as sources of antibacterial compounds, emphasizing their significance in combating antibiotic resistance (AMR). The crude extracts of Micrococcus, Bacillus, and Staphylococcus saprophyticus exhibited significant antibacterial activity, with inhibition zones measuring 12 mm and 14 mm against Escherichia coli, Staphylococcus aureus, Candida albicans, and other infectious strains. The DPPH assay showed that the bacterial isolates AN3 and AN6 exhibited notable antioxidant activity at a concentration of 100 mg/mL. To characterize the chemical constituents responsible for the observed bioactivity, a GC–MS analysis was performed on ethyl acetate extracts of the potent strains. The analysis identified a range of antimicrobial compounds, including straight-chain alkanes (e.g., Tetradecane), cyclic structures (e.g., Cyclopropane derivatives), and phenolic compounds, all of which are known to disrupt microbial membranes or interfere with metabolic pathways. The bioprospecting and large-scale production of these compounds are challenging. In conclusion, this study underscores the potential for marine bacteria associated with sponges from the Red Sea to be a source of bioactive compounds with therapeutic relevance. Full article

Anthozoa is a species-rich class with an innate immune system that acts as a defensive tool and shares many of its cellular pathways with mammalian immune responses. In addition to immune-related strategies (e.g., allorecognition and xenorecognition), anthozoans have evolved to use compounds or toxins for chemical communication, defense, or predation, which may exhibit biological activities useful for human health, mainly antiviral, antibacterial, anti-inflammatory, anticancer, and antitumor properties of pharmaceutical interest. These compounds/toxins can be alkaloids, amino acids, proteins, ceramides, diterpenes, and sesquiterpenes and are mainly distributed into Hexacorallia and Octocorallia. Anthozoans are enriched in defensive enzymes, which can either be found in anthozoan species or their symbionts and help them survive in hostile conditions. Studies related to genomics and transcriptomics using advanced sequencing efforts revealed the presence of genetic elements in anthozoans that help them survive against abiotic and biotic stressors in the marine environment. This review presents developments and highlights the current state of knowledge about anthozoans’ chemical weaponry that can drive further bioprospection of anthozoan species producing compounds and toxins which may be useful in biotechnological applications. Omics research in Anthozoa is still nascent, and more efforts are required to fully understand the chemical ecology, diversity, and possible biotechnological applications of cnidarian genes and their products. Full article

This study evaluated the antibacterial activity of aqueous and organic extracts from 78 marine organisms, including seaweeds and sponges, collected along the coast of Ceará, Brazil. Extracts were obtained by maceration using distilled water and 50% acetonitrile and tested against Staphylococcus aureus, Staphylococcus epidermidis (Gram-positive), and Escherichia coli (Gram-negative) using the disk diffusion method, and inhibition zone diameters were measured. Antibacterial activity was observed in 30.7% of the extracts, with organic extracts showing higher efficacy. Several sponge species, particularly those from the genus Aplysina, as well as Amphimedon compressa, Amphimedon viridis, Mycale sp., and Pseudosuberites sp., demonstrated notable inhibitory effects. While seaweed aqueous extracts showed no activity, some organic extracts—especially from Amansia multifida—were effective against Gram-positive strains. In general, Gram-positive bacteria were more susceptible than Gram-negative bacteria. These findings underscore the biotechnological potential of marine organisms from the Brazilian coast as promising sources of antibacterial compounds and support future efforts focused on the isolation, characterization, and toxicological evaluation of active metabolites for pharmaceutical and industrial applications. Full article

The marine environment is a rich source of new biotechnologies and products. Bottom trawling for shrimp species such as Xiphopenaeus kroyeri and Farfantepenaeus brasiliensis leads to the unintentional capture of non-target species, known as bycatch, which includes a variety of marine life that are often discarded without economic value. A common bycatch species on the southeast coast of Brazil is Olivancillaria urceus (O. urceus), a carnivorous gastropod that feeds mainly on bivalves. Despite its abundance, this species is still little studied, especially for biotechnological applications. Other gastropods such as Conus are known for their diverse and potent toxins, which offer great potential for pharmacological discoveries. In this study, an omics approach, including transcriptomics and proteopeptidomics, was applied to explore O. urceus at the molecular level. The transcriptome of the muscle foot/mantle led to the annotation of 19,097 genes via Gene Ontology, identifying 20 toxin-like transcripts identified considering the Gastropod class. The proteome fraction confirmed 2179 transcripts, including sequences with toxin activity, such as conotoxin precursors, Conodipine-P3, and BPTI/Kunitz domain-containing proteins. In addition, 9663 peptides of 1484 precursor proteins were detected in the peptide fraction, including 2 sequences representing neurotoxins. The identification of these sequences could lead to the discovery of new molecules with therapeutic potential. Full article

Marine microplastics (MPs) represent a novel ecological niche, populated by fungi with high potential for pharmaceutical discovery. This study explores the bioactivity of fungal strains isolated from MPs in Mediterranean sediments, focusing on their osteogenic and antiviral activities. Crude extracts prepared via solid-state and submerged-state fermentation were tested for their effects on extracellular matrix mineralization in vitro and bone growth in zebrafish larvae, and for their activity against the respiratory syncytial virus (RSV) and herpes simplex virus type 2 (HSV-2). Several extracts exhibited significant mineralogenic and osteogenic activities, with Aspergillus jensenii MUT6581 and Cladosporium halotolerans MUT6558 being the most performing ones. Antiviral assays identified extracts from A. jensenii MUT6581 and Bjerkandera adusta MUT6589 as effective against RSV and HSV-2 at different extents, with no cytotoxic effect. Although chemical profiling of A. jensenii MUT6581 extract led to the isolation of decumbenones A and B, they did not reproduce the observed bioactivities, suggesting the involvement of other active compounds or synergistic effects. These results highlight the plastisphere as a valuable resource for novel bioactive compounds and suggest the need for further fractionation and characterization to identify the molecules responsible for these promising activities. Full article

Fish body mucus plays a protective role, especially in Halobatrachus didactylus, which inhabits intertidal zones vulnerable to anthropogenic contaminants. In silico predicted bioactive peptides were identified in its body mucus, namely, EDNSELGQETPTLR (HdKTLR), DPPNPKNL (HdKNL), PAPPPPPP (HdPPP), VYPFPGPLPN (HdVLPN), and PFPGPLPN (HdLPN). These peptides were studied in vitro for bioactivities and aggregation behavior under different ionic strengths and pH values. Size exclusion chromatography revealed significant peptide aggregation at 344 mM and 700 mM ionic strengths at pH 7.0, decreasing at pH 3.0 and pH 5.0. Although none exhibited antimicrobial properties, they inhibited Pseudomonas aeruginosa biofilm formation. Notably, HdVLPN demonstrated potential antioxidant activity (ORAC: 1.560 μmol TE/μmol of peptide; ABTS: 1.755 μmol TE/μmol of peptide) as well as HdLPN (ORAC: 0.195 μmol TE/μmol of peptide; ABTS: 0.128 μmol TE/μmol of peptide). Antioxidant activity decreased at pH 5.0 and pH 3.0. Interactions between the peptides and mucus synergistically enhanced antioxidant effects. HdVLPN and HdLPN were non-toxic to Caco-2 and HaCaT cells at 100 μg of peptide/mL. HdPPP showed potential antihypertensive and antidiabetic effects, with IC₅₀ values of 557 μg of peptide/mL for ACE inhibition and 1700 μg of peptide/mL for α-glucosidase inhibition. This study highlights the importance of validating peptide bioactivities in vitro, considering their native environment (mucus), and bioprospecting novel bioactive molecules while promoting species conservation. Full article

Photosynthetic organisms are primary sources of marine-derived molecules, particularly ω3 fatty acids (FAs), which influence the quality of marine foods. It is reported that tropical organisms possess lower FA nutritional quality than those from colder oceans. However, the high biodiversity known for tropical areas may help compensate for this deficiency by producing a high diversity of molecules with nutritional benefits for the ecosystem. Here we addressed this aspect by analyzing the FA profiles of 20 photosynthetic organisms from the salty and warm Red Sea, a biodiversity hot spot, including cyanobacteria, eukaryotic microalgae, macroalgae, mangrove leaves, as well as three selected reef’s photosymbiotic zooxanthellate corals and jellyfish. Using direct transesterification, gas chromatography-mass spectrometry, FA absolute quantification, and nutritional indexes, we evaluated their lipid nutritional qualities. We observed interspecific and strain-specific variabilities in qualities, which the unique environmental conditions of the Red Sea may help to explain. Generally, eukaryotic microalgae exhibited the highest nutritional quality. The previously unanalyzed diatoms Leyanella sp. and Minutocellus sp. had the highest eicosapentaenoic acid (EPA) contents. The bioprospected Red Sea photobiota exhibited pharmaceutical and nutraceutical potential. By sourcing and quantifying these bioactive compounds, we highlight the untapped rich biodiversity of the Red Sea and showcase opportunities to harness these potentials. Full article

Marine habitats are increasingly facing human-induced stressors, posing significant threats to global marine biodiversity. Understanding the ecological, economic, and social importance of marine ecosystems is paramount. This study conducts a comprehensive bibliometric analysis of seaweed biodiversity from 1992 to 2023, aiming to (i) quantify the literature productivity, (ii) identify the active countries, (iii) determine the prolific authors, (iv) highlight the highly cited publications, and (v) enumerate the influential journals. The average annual number of publications was 37. Australia and the USA ranked highest based on the total number of citations, with 7559 and 5273, respectively. The University of Western Australia led in terms of the total number of citations, with 3688 citations from 40 publications, while the Australian Research Council emerged as the top funder. Journals such as the Journal of Experimental Marine Biology and Ecology, Ecology, and Botanica Marina were identified as the top contributors. The keyword ‘biodiversity’ appeared 146 times, with a total link strength of 425. A similar analysis was presented for endemic seaweeds and their conservation. Among the seven major and four emerging drivers, climate change was the most researched driver, accounting for 45.80%, with 120 articles. This study anticipates that in the genomic era, seaweed biodiversity will receive increased attention for its potential in regard to the development of coherent conservation plans and innovative bioprospecting strategies that are beneficial to humankind. Full article

Mercury pollution is a significant environmental issue, primarily resulting from industrial activities, including gold mining extraction. In this study, 333 microorganisms were tested in increasing mercury concentrations, where 158 bacteria and 14 fungi were able to grow and remain viable at concentrations over 5.0 mg/L of mercuric chloride (II). One of the bacterial strains, Stenotrophomonas sp. INV PRT0231, isolated from the mouth of the San Juan River in the Chocó region in Colombia, showed a high mercury resistance level (MIC₉₀ of 27 ± 9 mg/L), with a removal rate of 86.9%, an absorption rate of 1.2%, and a volatilization rate of 85.7% at pH 6.0 and 30.0 °C. The FTIR analysis showed changes in the functional groups, including fatty acid chains and methyl groups, proteins, and lipopolysaccharides associated with the carboxylate group (COO⁻), suggesting an important role of these biomolecules and their associated functional groups as mechanisms employed by the bacterium for mercury detoxification. Our study contributes to the understanding of the mechanisms of mercury biotransformation in microbial environmental isolates to help develop bioremediation strategies to mitigate mercury pollution caused by anthropogenic activities. Full article

Brown algae are vital structural elements and contributors to biodiversity in marine ecosystems. These organisms adapt to various environmental challenges by producing primary and secondary metabolites crucial for their survival, defense, and resilience. Besides their ecological role, these diverse metabolites have potential for biotechnological applications in industries including pharmaceuticals, cosmetics, and food. A literature review was conducted encompassing studies from 2014–2024, evaluating the effects of hydrodynamics, temperature, light, nutrients, seasonality, and salinity on the chemical profiles of various Phaeophyceae algae species. Thirty original articles spanning 69 species from the Sargassaceae, Dictyotaceae, Fucaceae, and Scytosiphonaceae families were analyzed and systematically arranged, with a focus on methodologies and key findings. This review furthers ecological discussions on each environmental factor and explores the biotechnological potential of metabolites such as polysaccharides, fatty acids, phenolics, diterpenes, and pigments. The information in this work is beneficial for metabolite bioprospecting and in vitro cultivation models as well as indoor and outdoor cultivation studies. Full article