Red Algae Research Articles

Seaweeds and Their Secondary Metabolites: A Promising Drug Candidate With Novel Mechanisms Against Cancers and Tumor Angiogenesis.

Cancer continually remains a severe threat to public health and requires constant demand for novel therapeutic drug candidates. Due to their multi-target orientation, lesser toxicity, and easy availability, natural compounds attract more attention from current scientific research interest than synthetic drug molecules. The plants and microorganisms produce a huge variety of secondary metabolites because of their physiological diversification, and the seaweeds occupy a prominent position as effective drug resources. Seaweeds comprise microscopic or macroscopic photosynthetic, multicellular, eukaryotic marine algae that commonly inhabit the coastal regions. Several molecules (such as polysaccharides, lipids, proteinaceous fractions, phenolic compounds, and alkaloids) are derived from seaweeds, and those small molecules are well attractive and more effective in cancer research programs. Their structural variation, derivative diversity, and quantity vary with seaweed species and geographical origin. Their smaller molecular weight, unique derivatives, hydrophobicity, and degree of sulfation are reported to be causes of their crucial role against different cancer cells in vitro. Several reports showed that those compounds selectively discriminate between normal and cancer cells based on receptor variations, enzyme deficiency, and structural properties. The present review aimed to give a concise explanation regarding their structural diversity, extractability, and mechanism of action related to their anti-cancer activities based on recently published data.

Assessing the potential of a genetically modified Parachlorella kessleri-I with low CO2 inducible proteins for enhanced biomass and biofuel productivity

The biological process is one of the promising approaches for CO2 capture and storage. Recently, biological sequestration using microalgae has gained much interest due to its capability to utilize CO2 as a carbon source to generate valorizable biomass. This algal biomass further can be used as a feedstock for bioenergy and different value-added products. Here, we have heterogeneously overexpressed the low CO2 inducible proteins (LCIA & LCIB) from Chlamydomonas reinhardtii in the marine alga Parachlorella kessleri-I. Incorporation of these two genes boosted the endogenous CCM leading to a hybrid system and improved overall carbon acquisition. The combination of these CCM proteins enhanced the supply of inorganic carbon to RuBisCO with positive effects on growth and biomass productivity. Biochemical analyses revealed that the hybrid CCM in P. kessleri-I was characterised by 2- fold higher carbonic anhydrase activity, increased starch, and 2X more lipid yield in comparison to wild type (WT) strain. Moreover, the semi-continuous cultivation of GM strain with supply of 1 % CO2 led to around 60 % rise in the overall biomass productivity. These traits also persisted in scale-up studies leading to 2X more biomass productivity in the GM strain than WT in 100 L PBR. A comparative life-cycle assessment underlines the sustainability of the process of carbon capture and both biofuel and biochar production from P. kessleri-I with a hybrid CCM.

Identification of Novel PBP2B Protein Inhibitors against Streptococcus pneumoniae in Marine Natural Products using an In-Silico Approach

Background: The aim of this research is to identify marine natural compounds derived from green, red, and brown algae that might possibly inhibit the Penicillin-Binding Proteins (PBPs) protein, which is responsible for the development of antibiotic resistance in Streptococcus pneumoniae (mutated resistant 5204-PBP2B strain). We obtained this by using virtual screening and molecular docking. In AutoDock Vina and the Schrodinger suite software, we screened a library of marine natural chemicals and discovered four intriguing candidates that had strong binding affinities to the active region of the PBPs protein. Based on our findings, four naturally occurring marine chemicals show great promise as new inhibitors of S. pneumoniae 5204-PBP2B protein. These discoveries reveal important new information on the potential application of marine natural products as a source of new drugs to combat antibiotic resistance in Streptococcus pneumoniae and other bacterial infections. Methods: The 3318 compounds in the Comprehensive Marine Natural Products Database (CMNPD) derived from green algae (293 compounds), brown algae (1212 compounds) and red algae (1813 compounds) were taken into consideration for this study. Through virtual screening and molecular docking investigations, we found the optimum compounds for the Penicillin-Binding Proteins (PBPs) protein in Streptococcus pneumoniae. Utilizing AutoDock Vina and Schrodinger Suite software, the 5204-PBP2B protein selected for this investigation was examined. The structure and binding interaction have been displayed using PyMOL software. Results: Through virtual screening and molecular docking investigations for the 5204-PBP2B protein in Streptococcus pneumoniae, we were able to identify four marine natural products that are present in brown algae from the Comprehensive Marine Natural Products Database. Conclusion: The study has indicated that the main cause of bacterial resistance to antibiotics is 5204-PBP2B in S. pneumoniae. This study's methodology has been shown to be effective in identifying four strong inhibitors of the CMNPD. In this work, potent molecules from CMNPD compounds were screened using the 3D structure of mutated resistant 5204 strain, named 5204- PBP2B (PDB ID: 2WAE) of S. pneumoniae. Out of 3318 compounds that showed strong interactions with PBP2B, docking studies revealed that four of the compounds were inhibitory for the protein and could be used to treat PBP2B. These four marine products were selected as a result of our earlier research on Klebsiella pneumonia’s New Delhi metallo-β-lactamase-1 (NDM-1) protein. This study thus reveals the importance of marine natural products for improving the drug development process, as well as the ability of four marine products generated from brown algae to inhibit both the NDM-1 protein of Klebsiella pneumoniae and the 5204-PBP2B protein in Streptococcus pneumoniae. It is also possible to expand this approach by investigating how different receptor inhibitors interact in a lab setting. Potential inhibitors can be discovered by evaluating the biological activity of the drugs and applying virtual screening and molecular docking techniques.

Marine Bioactive Compounds with Functional Role in Immunity and Food Allergy.

Food allergy, referred to as the atypical physiological overreaction of the immune system after exposure to specific food components, is considered one of the major concerns in food safety. The prevalence of this emerging worldwide problem has been increasing during the last decades, especially in industrialized countries, being estimated to affect 6-8% of young children and about 2-4% of adults. Marine organisms are an important source of bioactive substances with the potential to functionally improve the immune system, reduce food allergy sensitization and development, and even have an anti-allergic action in food allergy. The present investigation aims to be a comprehensive report of marine bioactive compounds with verified actions to improve food allergy and identified mechanisms of actions rather than be an exhaustive compilation of all investigations searching beneficial effects of marine compounds in FA. Particularly, this research highlights the capacity of bioactive components extracted from marine microbial, animal, algae, and microalgae sources, such as n-3 long-chain polyunsaturated fatty acids (LC-PUFA), polysaccharide, oligosaccharide, chondroitin, vitamin D, peptides, pigments, and polyphenols, to regulate the immune system, epigenetic regulation, inflammation, and gut dysbiosis that are essential factors in the sensitization and effector phases of food allergy. In conclusion, the marine ecosystem is an excellent source to provide foods with the capacity to improve the hypersensitivity induced against specific food allergens and also bioactive compounds with a potential pharmacological aptitude to be applied as anti-allergenic in food allergy.

Distribution and functional perspective analysis of epiphytic and endophytic bacterial communities associated with marine seaweeds, Alexandria shores, Egypt

There is an enormous diversity of life forms present in the extremely intricate marine environment. The growth and development of seaweeds in this particular environment are controlled by the bacteria that settle on their surfaces and generate a diverse range of inorganic and organic chemicals. The purpose of this work was to identify epiphytic and endophytic bacterial populations associated with ten common marine macroalgae from various areas along the Mediterranean Sea coast in Alexandria. This was done to target their distribution and possible functional aspects. Examine the effects of the algal habitat on the counting and phenotypic characterization of bacteria, which involves grouping bacteria based on characteristics such as shape, colour, mucoid nature, type of Gram stain, and their ability to generate spores. Furthermore, studying the physiological traits of the isolates under exploration provides insight into the optimum environmental circumstances for bacteria associated with the formation of algae. The majority of the bacterial isolates exhibited a wide range of enzyme activities, with cellulase, alginase, and caseinase being the most prevalent, according to the data. Nevertheless, 26% of the isolates displayed amylolytic activity, while certain isolates from Miami, Eastern Harbor, and Montaza lacked catalase activity. Geographical variations with the addition of algal extract may impact on the enumeration of the bacterial population, and this might have a relationship with host phylogeny. The most significant observation was that endophytic bacteria associated with green algae increased in all sites, while those associated with red algae increased in Abu Qir and Miami sites and decreased in Eastern Harbor. At the species level, the addition of algal extract led to a ninefold increase in the estimated number of epiphytic bacteria for Cladophora pellucida in Montaza. Notably, after adding algal extract, the number of presented endophytic bacteria associated with Codium sp. increased in Abu Qir while decreasing with the same species in Montaza. In addition to having the most different varieties of algae, Abu Qir has the most different bacterial isolates.

Extracellular Algae based Nanoparticles, Overview, Mechanisms and some Medical Applications

Algae and their metabolites are possessing variety of properties that enhance different medical, industrial and environmental fields. These organisms are distributed in nature and adapt to variety circumstances. Nanotechnology is a fast developmental scientific field that a huge number of researches have globally published in order to cover its applications and provide recent findings of this significantly important field. This paper display back ground on nanotechnology, definition and historical overview, as well as different techniques involving the use of algae to facilitate the production of nano materials. Focusing on three groups; brown(phaeophyta), red (rhodophyta) and blue green algae (cyanophyta) and their extracellular metabolites. In addition, several medical applications of algae based nanomaterials is discussed. Including the use of these nano-sized particles against bacteria, virus, biofilm producing microbes and bio sensing technique.

Hoefkenia hunsrueckensis, a New Genus and Species from Europe, and the Identity of Virescentia vogesiaca (F.W.Schultz ex Skuja) Necchi, D.C.Agostinho & M.L.Vis (Batrachospermales, Rhodophyta)

Freshwater red algae from Hunsrück-Hochwald National Park previously identified as Virescentia vogesiaca are described as Hoefkenia hunsrueckensis gen. et sp. nov. They cluster in the phylogenetic tree together with Kumanoa and form its sister clade. Virescentia is rendered monophyletic by exclusion of these samples. The taxonomic history of Virescentia vogesiaca is described. The species was named by Skuja referring to the description of Batrachospermum vagum var. flagelliforme Sirodot and the specimens all come from Western France and Spain. The name Batrachospermum vogesiacum was erroneously applied referring to a specimen from the North Vosges close to Germany collected and annotated by F.W. Schultz and representing the new Hoefkenia hunsrueckensis. However, this specimen was never cited in the protologue of Virescentia vogesiaca. We provide evidence that the real Virescentia vogesiaca is endemic to Western France and Spain, and that Hoefkenia hunsrueckensis is restricted to Eastern Belgium, Eastern France and SW Germany, differing in morphological and molecular characters.

Taxonomy of Leodice Lamarck, 1818 (Annelida, Eunicidae) from Northeast Brazil (Tropical Southwest Atlantic Ocean) with description of a new species

Currently, Leodice has 34 species recorded worldwide. Among these, seven species are known along the Brazilian coast. This study is based on material collected during the Marine Algae project conducted in 1981 along the Continental Shelf of the State of Paraíba, at depths of 10–35 m. In this study, we present three new records: L. pellucida comb. nov. for South America, L. marcusi for northeastern Brazil, and L. unifrons for the State of Paraiba. A new species of Leodice is described from the State of Paraiba, Northeast Brazil, Leodice ivanildae sp. nov. This taxonomic study increases the number of known species of Leodice to 37, with nine occurring in Brazil. Additionally, it expands the species of Leodice known from the State of Paraiba, Brazil, from two to six.

Characteristics of Films Prepared from Wheat Gluten and Phenolic Extracts from Porphyra haitanensis and Its Application for Salmon Preservation.

The effect of wheat gluten (WG)/phenolic extracts (PE) coating on the storage qualities of salmon fillets was studied. Porphyra haitanensis, belonging to red algae, possesses abundant phenolic compounds. Films were prepared by incorporating phenolic extracts (0, 0.5%, 0.75%, and 1.0%, w/v) from Porphyra haitanensis to WG. The PE showed strong antioxidant activities by scavenging DPPH and ABTS radicals. The increased addition of PE to WG film significantly increased tensile strength compared to that of WG film, but reduced water vapor permeability. The quality of salmon fillet stored at 4 °C from 0 to 9 days was decreased due to the oxidation of lipid and protein. However, the increased addition of PE to WG significantly reduced pH, TVB-N, TBA, peroxide value, total sulfhydryl content, and carbonyl content of salmon fillet compared to control salmon fillet. In addition, the increased addition of PE to WG also significantly improved water holding capacity, hardness, chewiness, and springiness of salmon fillet during storage compared to those of control salmon fillet. Taken together, this study showed phenolic extracts from Porphyra haitanensis improved wheat gluten-based film properties and further enhanced the qualities of coated salmon fillet during storage.

Marine algae biomass: A viable and renewable resource for biofuel production: A review

Global energy shortages, as well as rising greenhouse gas emissions, have fueled the search for sustainable renewable energy sources. Recent research has identified microalgae and macroalgae biofuel as one of the major renewable energy sources for environmentally friendly growth, with the potential to replace fossil-based energy sources. The primary disadvantages associated with oil crops and lignocellulose-based biofuels were absent in marine microalgae and macroalgae biofuel. Algae-based renewable energy sources are technically and economically viable, as well as cost competitive; they require no additional land, use little water, and help to reduce atmospheric CO2. Commercial extraction of macroalgae and microalgae biofuel, however, remains impossible due to a small biomass amount and costly downstream procedures. Marine algae-based biofuel production can be made viable by installing sophisticated photobioreactors and developing low-cost biomass collection, drying, and oil recovery technologies. Commercial manufacturing is also achieved through improved genetically modified approaches to stress management, as well as technological metabolic processes to increase lipid production. Furthermore, emerging technologies such as algal-bacterial interactions for improving marine algae growth and lipid production are being investigated. This review focuses on marine algae-based biofuel production and sustainability, economic values, challenges encountered during the commercialization of marine algae biofuels, potential solutions to these challenges, and practicality.

Genome-wide identification, transcriptional analysis, and acetylated histone site recognition of the Bromodomain gene family in Pyropia yezoensis

The bromodomain (BRD) is a protein domain that recognizes acetylated lysine residues and plays a pivotal role in chromatin remodeling and the recruitment of transcription factors, thereby regulating gene transcription. Although extensively studied in animals and plants, the presence and function of BRD genes in red algae remain unexplored. This study identified 10 BRD family genes in red seaweed, Pyropia yezoensis, all of which encode proteins with conserved bromodomains. Six of these proteins (PyGTE9, PyNPX, PyGTE7, PyGCN5, PyBRAT, and PyBRD-WD40) exhibited a highly conserved domain organization similar to that of plant BRDs. Additionally, a unique BRD type, Tudor, was found exclusively in red algae and possibly had dual histone acetylation and methylation affinities. Regarding evolutionary dynamics, the number of BRD family members in P. yezoensis was highly conserved in Rhodophyta, albeit exhibited a distant phylogenetic relationship with Arabidopsis thaliana. Interestingly, some red-algae-specific BRD genes were discovered. Collinearity analysis showed that all BRD genes were syntenic in P. yezoensis and P. haitanensis. Pull-down assays with acetylated histone peptides revealed that the BRD of PyGTE9 has a strong binding affinity to H3K18ac, H4K5ac, H4K8ac, and H4K16ac. Finally, transcriptional profile analysis further revealed that these BRD genes exhibited differential expression under wound stress and dehydration stress across two generations of P. yezoensis. In summary, our findings provide an understanding of the evolutionary, structural, and transcriptional dynamics under abiotic stresses of the P. yezoensis BRD family members and further clarify the histone recognition attributes of PyGTE9. This study provides valuable insights for future research into the function of the P. yezoensis BRD family genes.

GC/MS analysis and evaluating of antifungal potency of algal organic extracts against environmental and clinical identified fungal strains

Marine algae are promising biologically active compounds that can be used for antimicrobial activity. The objective of this study was to evaluate the antifungal activity of seven seaweed extracts, collected from Sidi Bouzid, El Jadida (Morocco), against three fungal strains, Aspergillus steynii, Chaetomium elatum and Chaetomium globosum, responsible of numerous impacts on the environment and human health. For that, the minimal inhibitory concentration (MIC) and the chemical composition of the most active extracts were determined.The results obtained prove that methanolic extract of Osmundea pinnatifida and Ellisolandia elongata has the highest yield, followed by ethyl acetate extract of Jania rubens. Chaetomium elatum and Chaetomium globosum were the most sensitive strains using most of the organic seaweed's extract, compared to Aspergillus steynii, with 100 % of inhibition. Compared to other extracts, the ethyl acetate extract of Osmundea pinnatifida had the strongest antifungal activity with MIC of 1.95 μg/mL against Chaetomium globosum, the second strongest antifungal activity was observed using methanolic extract of Ellisolandia elongata with an MIC of 7.8 μg/mL. Chemical analysis of the active seaweeds' organic extracts shows the presence of different components dominated by heptadecanoic acid in methanolic extract of Ellisolandia elongata and methyl tetradecanoate in Osmundea pinnatifida and Bornetia secundiflora, which are known for their antibacterial and antifungal activities and may be responsible for the activity observed.

Isoprene emission dynamics in Chaetoceros curvisetus: Insights from transcriptome analysis under light/dark cycles

Isoprene from marine emissions significantly influences the atmospheric oxidative capacity and secondary pollutants in the marine boundary layer. While marine algae are recognized as primary contributors to marine emissions of isoprene, the long-term and dark-phase isoprene production from these organisms remains underexplored, potentially lead to inaccuracies in estimating marine isoprene emissions. In this study, we conducted a time series investigation of isoprene emission from Chaetoceros curvisetus with a growth cycle duration of 19 days and examined the influence of environmental factors. Our findings revealed that C. curvisetus emits isoprene during its whole growth cycle, with peak emissions (2.82 × 10−11 μmol cells−1 h−1) recorded in the stationary phase. Under nitrogen, light and temperature stress, significant release of isoprene is found. During both the light and dark phases, isoprene emission was observed with comparable intensities. Transcriptome analysis showed that 41 differentially expressed transcripts were involved in the synthesis of volatile organic compounds. Notably, downregulation of genes associated with pyruvate synthesis in the glycolysis pathway suggests its importance for dark isoprene release. The study also highlighted downregulation of isopentenyl phosphate kinase and Gene Ontology enrichment in organelles housing mevalonate (MVA) pathways, suggesting that exchange involving the transport of intermediate metabolites between MVA and methylerythritol phosphate (MEP) pathway may contribute to the released isoprene in dark phase. Furthermore, the synthesis of substrates and downstream products is related to the dark release of isoprene. In conclusion, our study illuminates the pivotal roles of substrate availability, interplay between MVA and MEP pathways, and glycolysis pathway in governing isoprene emissions under light/dark cycles.

Molecular Docking, Acute Toxicity and Antibacterial Study of Debilon and Phorbasterone-B Extracted from Rhodophyta

Introduction: Natural compounds obtained from marine algae, especially Rhodophyta are now being investigated for various biological activities. However, the antimicrobial activity and toxicity profile of compounds present in these algae isunderexplored. Objective: This study procured two compounds, Debilon and Phorbasterone-B, from Rhodophyta to analyze their in silico and in vitro potential against pathogenic bacterial strains and their acute toxicity. Methods: Debilon and Phorbasterone-B were extracted from Rhodophyta by a previously reported method and were further subsequently exploited computationally for their physicochemical properties, prediction of biological activity and molecular docking against bacterial proteins, toxicity, and experimentally for antibacterial potential against pathogenic strains of Vibrio cholera, Salmonella typhi, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa. Results: Docking studies proved that these molecules possess a chemical affinity for the bacterial proteins and can inhibit the growth of these microorganisms, as confirmed by antibacterial assay. Whereas the prediction analysis and toxicity studies showed that the friendliness of these molecules to the human body is enormous. Conclusion: From this study, it has been proved that DN and PB are perfect candidates for inhibiting these bacterial strains.

Why did the world's largest green tides occur exclusively in the southern Yellow Sea?

The world's largest green tide, caused by the nuisance green algae Ulva prolifera, has occurred in the southern Yellow Sea for 16 consecutive years. It is puzzling why the extensive floating green tide occurs exclusively in the southern Yellow Sea, rather than other waters. We speculate that the transition of U. prolifera from a sessile state to a surface-floating one is the underlying cause of the floating green tide. Here we founded that the floating of U. prolifera was attributed to detachment from substrata and appropriate desiccation. The convergence of unreasonable green algae disposal, geographical features and farming patterns of Porphyra (economic red algae) in Subei Shoal contributed to mass production of floating U. prolifera, resulting in the exclusive occurrence of the floating green tides. Inducing the natural inactivation of green algae to prevent the floating of U. prolifera may effectively mitigate the extensive Ulva bloom at zero cost.

Review of the protist Labyrinhula spp. and its relationship to seagrass disease under the influence of anthropogenic activities.

Anthropogenic activities are driving significant changes in coastal ecological environments, increasingly spotlighting microorganisms associated with seagrass bed ecosystems. Labyrinthula is primarily recognized as a saprophytic protist associated with marine detritus, and it also acts as an opportunistic pathogen affecting marine algae, terrestrial plants and mollusks, especially in coastal environments. The genus plays a key role in the decomposition of marine detritus, facilitated by its interactions with diatoms and through the utilization of a diverse array of carbohydrate-active enzymes to decompose seagrass cell walls. However, human activities have significantly influenced the prevalence and severity of seagrass wasting disease (SWD) through factors such as climate warming, increased salinity and ocean acidification. The rise in temperature and salinity, exacerbated by human-induced climate change, has been shown to increase the susceptibility of seagrass to Labyrinthula, highlighting the adaptability of pathogen to environmental stressors. Moreover, the role of seagrass in regulating pathogen load and their immune response to Labyrinthula underscore the complex dynamics within these marine ecosystems. Importantly, the genotype diversity of seagrass hosts, environmental stress factors and the presence of marine organisms such as oysters, can influence the interaction mechanisms between seagrass and Labyrinthula. Besides, these organisms have the potential to both mitigate and facilitate pathogen transmission. The complexity of these interactions and their impacts driven by human activities calls for the development of comprehensive multi-factor models to better understand and manage the conservation and restoration of seagrass beds.

Characteristics of carrageenan from seaweed hydrolysis using marine fungi as hard-shell capsule material

Carrageenan is a polysaccharide extracted from red algae and can be used as a raw material for hard-shell capsules. Carrageenan can be produced by biological hydrolysis of marine fungi. The viscosity of carrageenan resulting from hydrolysis using marine fungi is lower than that of commercial carrageenan. Gelatine can be used to modify the characteristics of polysaccharide-based materials. The characteristics and types of carrageenan and plasticizers influence the interactions between carrageenan and gelatin. This study aimed to determine the characteristics of carrageenan produced by seaweed hydrolysis of a hard-shell capsule material. The physical characteristics of the carrageenan produced by hydrolysis were determined, including yield, viscosity, and gel strength. The properties of the hard-shell capsules, including dimensions, capsule weight, disintegration time, and moisture content, were analyzed. The yield was 25%, and the viscosity and gel strength of carrageenan were 45 cP and 175 gf, respectively. Carrageenan contains 13% moisture, 8% ash, and 8% cellulose. Semi-refined carrageenan produced by this treatment was used to prepare hard-shell capsules. The capsule made from semi-refined carrageenan had a body length of 18 mm, capsule length of 10 mm, capsule weight of 0.9 grams, disintegration time of 10 min, and moisture content of 12%.

Antibacterial and Immunosuppressive Effects of a Novel Marine Brown Alga-Derived Ester in Atopic Dermatitis.

Atopic dermatitis (AD) is a chronic skin condition that is characterized by dysregulated immune responses and a heightened risk of Staphylococcus aureus infections, necessitating the advancement of innovative therapeutic methods. This study explored the potential of (6Z,9Z,12Z,15Z)-(2R,3R,4R,5R)-2,3,4,5,6-pentahydroxyhexyl octadeca-6,9,12,15-tetraenoate (HSN-S1), a compound derived from the marine alga Hizikia fusiformis, which shows anti-inflammatory, antimicrobial, and immunomodulatory properties. HSN-S1 was isolated and characterized using advanced chromatographic and spectroscopic methods. Its efficacy was evaluated via in vitro assays with keratinocytes, macrophages, and T cells to assess cytokine suppression and its immunomodulatory effects; its antibacterial activity against S. aureus was quantified. The in vivo effectiveness was validated using a 2,4-dinitrochlorobenzene-induced AD mouse model that focused on skin pathology and cytokine modulation. HSN-S1 significantly reduced pro-inflammatory cytokine secretion, altered T-helper cell cytokine profiles, and showed strong antibacterial activity against S. aureus. In vivo, HSN-S1 alleviated AD-like symptoms in mice and reduced skin inflammation, transepidermal water loss, serum immunoglobulin-E levels, and Th2/Th17 cytokine outputs. These findings suggest HSN-S1 to be a promising marine-derived candidate for AD treatment, as it offers a dual-target approach that could overcome the limitations of existing therapies, hence warranting further clinical investigation.

Bioadsorption of crude petroleum oil from seawater using the marine alga Hormophysa triquetra mediated silver nanoparticles

The biosynthesis of silver nanoparticles, both economically and environmentally advantageous, uses algae extracts. In the current work, we extracted the marine brown alga Hormophysa triquetra (C. Agardh) kützing and used it to make silver nanoparticles (HAgNPs) which are characterized via UV–visible spectrophotometers, Transmission Electron Microscopy (TEM), Zeta potential, and FTIR then used them in the bio adsorption of crude petroleum oil from seawater, comparing them with H. triquetra aqueous extract. UV scan of the phycosynthesized silver nanoparticles achieved the highest absorption at 369 nm. TEM showed that the synthesized HAgNPs occur with smooth, spherical, and semispherical forms with sizes ranging from 12.04 to 20.67 nm, zeta potential illustrated that HAgNPs were charged with −22.1, The H. triquetra aqueous extract's FTIR examination identified several active groups like – OH, –C=C–, NO, –CH, CCl, –C ≡ C–H: CH which are responsible for the bioadsorption of crude petroleum oil. When extracting crude petroleum oil from seawater, HAgNPs worked better than its aqueous extract. The maximum removal % for light n-alkanes (Ln-alk), heavy n-alkanes (Hn-alk), and PAHs were 70.4 %, 71.63 %, and 75.38 % respectively for H. triquetra aqueous extract with adsorption capacity 889, 511, 273 μg/g at salinity 36 % and pH 5, while in case of HAgNPs the results were 75.81 %, 77.15 %, and 80.56 %, respectively with adsorption capacity 957, 550, 292 μg/g at the same salinity and pH.

Rheological and Structural Characterization of Carrageenans during Depolymerization Conducted by a Marine Bacterium Shewanella sp. LE8.

Carrageenans were widely utilized as thickening and gelling agents in the food and cosmetic industries, and their oligosaccharides have been proven to possess enhanced physicochemical and biological properties. In this study, Shewanella sp. LE8 was utilized for the depolymerization of κ-, ι-, and λ-carrageenan under conditions of fermentation. During a 24-h fermentation at 28 °C, the apparent viscosity of κ-, ι-, and λ-carrageenan decreased by 53.12%, 84.10%, and 59.33%, respectively, accompanied by a decrease in storage modulus, and loss modulus. After a 72-h fermentation, the analysis of methylene blue and molecular weight distribution revealed that ι-carrageenan was extensively depolymerized into smaller polysaccharides by Shewanella sp. LE8, while exhibiting partial degradation on κ- and λ-carrageenan. However, the impact of Shewanella sp. LE8 on total sugars was found to be limited; nevertheless, a significant increase in reduced sugar content was observed. The ESIMS analysis results revealed that the purified components obtained through ι-carrageenan fermentation for 72 h were identified as tetrasaccharides, while the two purified components derived from λ-carrageenan fermentation consisted of a hexasaccharide and a tetrasaccharide, respectively. Overall, the present study first reported the depolymerization of ι-and λ-carrageenan by Shewanella and suggested that the Shewanella could be used to depolymerize multiple carrageenans, as well as complex polysaccharides derived from red algae, to further obtain their oligosaccharides.