Ulvan acts as a prebiotic polysaccharide enhancing the production of indoles and short-chain fatty acids in vitro: a metabolomics study.

Seaweed are primary producers and potential vectors of microplastics (MPs) contamination, yet robust extraction methods that digest complex algal matrices while preserving polymer integrity remain limited. A sequential enzymatic-oxidative digestion was optimized for three seaweeds (Fucus vesiculosus, Chondrus crispus and Ulva lactuca). The optimized process involved the initial addition of cellulase (1% w/v, 24 h, 50 °C) followed by H₂O₂ (30% v/v, 48-72 h, 65 °C). Across nine 0.5 g dry-weight sub-replicates (3 per seaweed), 30 MPs were found (6.7 MPs/g⁻¹). The integrity of polymers was assessed for 12 MPs polymers, with acceptable performance being defined as ≥ 90% recovery and spectroscopic (through FTIR analysis) identifiability. Eight polymers met this threshold (90-101%). Four polymers were adversely affected with the long 72 H₂O₂ incubation, namely: cellulose-acetate (53% recovery), polyamide (61%), acrylic (3%) and rayon (2%). Although polymers remained identifiable, sequential digestion produced mass loss and visible changes (e.g. polyamide opacity, cellulose-acetate brittleness), which may increase fragmentation and miss-identification. Therefore, the protocol is suitable for most common MPs, but not for rayon and acrylic, and should be applied cautiously where cellulose-acetate or polyamide are expected.

Surface sediments, mussels, and macroalgae were collected to investigate metal accumulation, distribution, pollution levels, and sources from Gemlik Bay in the southeastern Sea of Marmara. The elements Cu, Zn, V, Co, Cr, Pb, Ni, and Mn were determined in macroalgae (Ulva lactuca Linnaeus,1753), (Ulva intestinalis, Linnaeus, 1753) and mussel (Mytilus galloprovincialis, Lamarck, 1819) samples, while Al and Fe were also determined in sediment samples in addition to these metals. Element accumulation and metal contamination levels were determined, and health risks from mussel and macroalgae consumption were assessed across age groups. The average enrichment factor (EF) calculated for sediment samples indicates that the contamination originates from anthropogenic sources, while the contamination factor (Cf) indicates that the contamination is at a low level. Additionally, the potential ecological risk (Er) and index (PERI) reveal that, except for lead (Pb), the ecological factors for other metals are low. In addition, according to the average geochemical index (Igeo) results, sediments were uncontaminated with Mn and Al, slightly contaminated with Fe, slightly to moderately with Cr and Pb, and moderately with Zn. Detected metals in mussels and macroalgae were assessed for health risks across age groups for the first time. Accordingly, the daily chronic intake (CDI) was calculated, and separate hazard index (HI) and target hazard quotient (THQ) values were determined for each age group. Children were identified as the most vulnerable group, highlighting the need for caution in their consumption of seafood, especially mussels and macroalgae.

Unlocking the phytochemical and biological attributes of Ulva lactuca and Sargassum muticum extracts: Antioxidant and antimicrobial activity, and phenolic compounds identification by UPLC-HRMS Orbitrap

Ulvan, a sulfated polysaccharide extracted from the sea lettuce, is gaining wider appreciation for its health-promoting and medicinal qualities. In the current study, Ulva lactuca was collected from the coastal site of Monastir, Tunisia. Ulvan was extracted and characterized using Fourier-transform infrared (FTIR) spectroscopy, confirming the presence of characteristic sulfate and carboxyl groups. The antiradical, antioxidant activity, and carbohydrate content were also estimated. The photoprotective effects of ulvan were evaluated in human keratinocyte (HaCaT) cells exposed to UVB radiation. Pre-treatment with ulvan (25 and 50µg/mL) significantly enhanced cell viability, reduced reactive oxygen species (ROS) production, preserved lysosomal function, and inhibited apoptosis. Additionally, ulvan enhanced cell migration and enhanced adhesion on extracellular matrix proteins, including laminin, collagen I, poly-L-lysine, vitronectin, and fibrinogen, demonstrating its role in maintaining cellular integrity under UVB stress. An enriched-ulvan emulsion was formulated. SPF evaluation suggested limited sunscreen effectiveness. Therefore, the photoprotective effects are mediated via antioxidant and cytoprotective mechanisms. This result support its potential as a natural marine-derived ingredient for functional cosmetic and dermatological products.

So far, space exploration has attracted increasing scientific interest due to the growth of missions promoted by private investment, such as SpaceX, Boeing, Blue Origin, and the recent attention generated by astronomical phenomena such as 3I/ATLAS. However, access to space experimentation remains limited and expensive. For this reason, new approaches to simulate space conditions on Earth are being developed to broaden research opportunities bio-inspired by plant responses to phototropism and geotropism. In this context, Betta Aerospace has continued the development of a microgravity simulation system consisting of a 3-axis clinostat powered by a single motor, continuous external electrical supply, and, in this project, a continuous external liquid supply. The proposed pioneer system was designed as a flexible platform manufactured through reinforced 3D printing, with an approximate size of 30 cm, an estimated payload of 30 kg, and a 24 V supply. Its main goal is to study the effects of simulated microgravity on aquatic organisms while enabling longer observation times in a controlled freshwater environment. Candidate biological samples include Ulva lactuca, Pyropia, Spirulina/Arthrospira, and Chlorella. Preliminary motion tests confirmed continuous operation at 10 rpm. In addition, a simplified static finite element analysis under a 294 N load yielded a maximum von Mises stress of 5.45 × 107 Pa and a maximum displacement of 1.73 mm.

Marine macroalgae are increasingly utilized in functional foods and pharmaceuticals; however, their tendency to bioaccumulate heavy metals poses potential consumer health risks. This study assessed the concentrations of nine heavy metals (As, Cd, Co, Cr, Cu, Hg, Ni, Pb, and Zn) in green, brown, and red macroalgae collected from ten coastal regions across Palk Bay and the Gulf of Mannar. Findings indicated significant metal concentrations, notably Arsenic (71.06 ± 0.12µg/g) and Copper (127.71 ± 0.04µg/g), with several species exceeding international food safety limits for As, Cd, and Pb. Species-specific accumulation was evaluated using the Metal Pollution Index (MPI). Enteromorpha fluxiosa (4.634) and Lobophora variegata (3.704) exhibited the highest MPI values, while Ulva lactuca and Porphyra indica showed negligible accumulation. Health risk assessments revealed that E. fluxiosa, Sargassum wightii, and Portieria hornemannii pose significant non-carcinogenic risks, as their Hazard Index (HI) values exceeded the safety threshold (HI > 1), primarily driven by arsenic and copper levels. In contrast, U. lactuca and Gelidiella acerosa maintained lower HI values, suggesting higher safety for human consumption. Statistical analyses, including Cluster Analysis and PCA, differentiated two primary groups: green algae with lower accumulation and red and brown algae with higher levels attributed to complex cell wall compositions. PCA identified Cd, Cu, Zn, Pb, and Co as primary drivers of species distribution, positioning U. lactuca and S. wightii as effective bioindicators. These results underscore the critical necessity for regular monitoring and stringent regulatory frameworks to ensure the safety of seaweed-derived products.

On the detection of foodborne viral contamination in edible seaweeds.

Hyaluoleosome-encapsulated Ulva lactuca extract for targeted photoprotection against UV-induced skin damage

Anticancer potential of Ulva lactuca extract: inhibition of growth kinetics and radial invasion in 3D tumor spheroids

ABSTRACT The high cost of conventional culture media restricts large-scale cultivation of Ulva lactuca, highlighting the need for affordable nutrient alternatives. This study evaluated agricultural fertilizers, urea and diammonium phosphate (DAP), as nitrogen and phosphorus sources, respectively. Five treatments – urea (UE), DAP (DP), urea + DAP (UD), no urea (NU), and no phosphate (NP) – were tested under controlled laboratory conditions for 21 days with three replicates (n = 3). Growth, pigment content, gross primary productivity, and total antioxidant capacity were analyzed. Fresh weight increased 4.60, 2.97, and 4.06-fold in UE, DP, and UD treatments, respectively, compared to the control. UE and UD showed significantly higher gross primary productivity (p < .05). Regression analysis predicted a 13.85% biomass increase (R 2 = 0.79) under UD at 0.81:0.48 g L−1 (urea:DAP). These findings indicate that urea and DAP based formulations effectively enhance biomass and physiological performance under optimized conditions.

Optimized production and characterization of ulvan from Ulva Lactuca with in vitro biological activities.

Modulation of gut microbiota and microbial metabolites during in vitro colonic fermentation of Ulva lactuca: Release and bioconversion of phlorotannins.

Comparative immunomodulatory and gut microbiota-regulating effects of macroalgal polysaccharides in cyclophosphamide-induced immunosuppressed mice.

Ulva lactuca polysaccharide composite film: Preparation and application in large yellow croaker (Larimichthys crocea) preservation

Macroalgae are an abundant and underutilized renewable feedstock that can be exploited for the production of various low- and high-value biomolecules. The study herein describes a mild acid and base process to hydrolyze the green macroalgae Ulva lactuca into simpler, fermentable carbohydrates, with an emphasis on rhamnose. Hydrolysis experiments involving up to 5% v/v sulfuric acid and 5% w/v sodium hydroxide at temperatures between 25 and 100 °C demonstrated that the highest recovery of fermentable carbohydrates was generally obtained using 2.5% v/v sulfuric acid at 75 °C. Two Clostridium species (Clostridium strain AK1 isolated from SW Iceland, and Clostridium beijerinckii strain DSM 791) were used to ferment L-rhamnose to 1,2-propanediol, both as a single substrate and as part of macroalgal hydrolysates. Additionally, the impact of culture conditions (pH and initial substrate concentration) on rhamnose fermentation was investigated in batch culture for both strains. Generally, pH did not influence the production of 1,2-propanediol and both strains partially degraded rhamnose at very low (10 mM) initial substrate concentrations. A kinetic investigation of rhamnose utilization using strain AK1 showed that the pentose is degraded much slower as compared with glucose with 1,2-propanediol production lagging and reaching a maximum concentration of 7.7 mM. When Clostridium strain AK1 was cultivated on U. lactuca hydrolysates and non-pretreated U. lactuca, the maximum yields were 7.9 mM 1,2-propanediol. This is the first report of the production of 1,2-propanediol from macroalgal biomass using a moderately thermophilic Clostridia.

Graphical Abstract Highlight Research 1. A natural functional seasoning was successfully developed from Ulva lactuca without synthetic additives. 2. The seasoning demonstrated high nutritional value, including 8.67% protein, 20.78% dietary fiber, and 59.21% carbohydrates. 3. Amino acid profiling revealed exceptionally high levels of L-glutamic acid and L-aspartic acid, enhancing natural umami flavor. 4. Phytochemical screening confirmed the presence of antioxidant-rich compounds such as flavonoids, phenolics, saponins, and alkaloids. 5. Heavy metal, microbiological, and color analyses demonstrated compliance with food safety standards and strong pigment stability. 6. Shelf-life testing showed product stability up to 9.23 months in metallocene packaging, with high sensory acceptability on potato-based snacks. Abstract Seaweeds have gained increasing attention as natural food ingredients due to their nutritional value, potential to replace synthetic additives, and environmental sustainability. However, the utilization of Ulva lactuca as a natural functional seasoning remains limited, particularly regarding safety assurance, sensory acceptance, and product shelf stability. This study aimed to evaluate the potential of U. lactuca as a natural functional seasoning by assessing its nutritional composition, safety, sensory properties, and storage stability. Samples were collected from Pangandaran, Yogyakarta, and Lombok, Indonesia. Analyses included proximate composition, amino acid profiling, phytochemical screening, heavy metal contamination, microbiological quality, color stability, sensory evaluation, and shelf-life estimation. A seaweed-based seasoning was formulated using Lombok samples without synthetic flavor enhancers. The formulated product demonstrated a favorable nutritional composition, containing 8.67 % protein, 20.78 % dietary fiber, and 59.21 % carbohydrates. High concentrations of L-glutamic acid (53,109.10 mg/kg) and L-aspartic acid (5,772.20 mg/kg) contributed to its umami taste. Phytochemicals, including flavonoids, phenolics, saponins, and alkaloids, were detected. Hg, Pb, As and microbiological parameters met food safety standards, Cd exceeded the limit in some raw samples. The product exhibited strong green (a* = –10.96) and yellow (b* = 9.99) color attributes and an estimated shelf life of 9.23 months when packaged in metallocene film. Sensory evaluation indicated high consumer acceptability, particularly when applied to potato- and Chitato Lite-based snacks. Overall, U. lactuca shows strong potential as a safe, sustainable, and nutrient-rich functional seasoning. Further research should focus on scale-up processing and the exploration of broader food applications.

This study addresses the need to enhance the antifungal activity of toothpaste formulations while ensuring the use of safe and biocompatible synthesis approaches. Therefore, this study aimed to develop silver nanoparticles (AgNPs) via a green approach to improve antifungal performance in toothpaste formulations, using Moringa oleifera leaf extract as a safe bioreductor and ulvan as a stabilizing agent. Moringa oleifera leaves were extracted by maceration using 96% ethanol, while ulvan was isolated from Ulva lactuca through acid extraction and enzymatic treatment. AgNPs were synthesized at varying extract concentrations (0.3% - 0.7%), labeled as E1 - E5, and characterized using UV-Vis spectroscopy, particle size analysis, zeta potential measurement, FTIR, and PXRD. The AgNP formation was confirmed by a color change to reddish-brown and a distinct SPR band, with λmax shifting with increasing extract concentration. Particle size ranged from 438 - 699 nm, indicating aggregation, while zeta potential values (−4.9 to −12.6 mV) suggested moderate colloidal stability. FTIR analysis of alginate beads containing AgNPs revealed characteristic O–H, COO⁻, and C–O–C bands, confirming metal-carboxylate interactions, whereas PXRD showed crystalline Ag peaks. Toothpaste formulations (F1 - F5) incorporating the beads were evaluated for physical properties, antifungal activity, and stability. All formulas exhibited acceptable organoleptic characteristics, homogeneous texture, and the physical properties meeting SNI standards. Antifungal testing demonstrated inhibition zones of 19 - 22 mm, with higher AgNP concentrations yielding stronger activity. Stability testing over 14 days indicated no significant changes in color, odor, homogeneity, pH, foaming, or spreadability, with slight decreases in viscosity. In conclusion, F3 showed the most favorable balance of physical stability, AgNP incorporation (6.01 ± 0.08 mg/L), and antifungal performance. These findings demonstrate that green-synthesized AgNPs encapsulated in alginate beads have strong potential for incorporation into safe and effective antifungal toothpaste formulations. HIGHLIGHTS Silver nanoparticles (AgNPs) were successfully synthesized via an eco-friendly green synthesis method using Moringa oleifera leaf extract as a bioreductant and ulvan as a natural stabilizing agent. Characterization (UV–Vis, FTIR, PXRD, particle size, zeta potential) confirmed AgNP formation, metal–carboxylate interactions, and crystalline FCC silver structure, validating the success of the synthesis and encapsulation process. AgNP-loaded alginate beads demonstrated strong antifungal activity (19 - 22 mm inhibition zones) against Candida albicans ATCC 10231 and the toothpaste formulation exhibited excellent physicochemical performance and 14-day stability, meeting SNI standards for viscosity, pH, spreadability, foamability, and overall organoleptic quality. GRAPHICAL ABSTRACT

The increasing presence of synthetic dyes in aquatic systems, particularly sunset yellow (SY), has raised urgent concerns due to their toxicity and persistence. In this work, a novel biochar derived from the marine green alga Ulva lactuca was investigated, for the first time, as a sustainable and high-performance adsorbent for SY removal. Comprehensive characterization—including proximate analysis, iodine number (190 mg/g), methylene blue index (59.5 mg/g), point of zero charge (pHpzc = 10.90), zeta potential, FTIR, TGA/DSC, XRF, XRD, SEM, and BET surface area (150.2 m²/g) revealed a mesoporous structure (pore diameter ≈ 19 nm, IUPAC Type IV) with heterogeneous cavities, low ash and moisture contents, and stable carbon formation. The coexistence of amorphous carbon and mineral phases (KCl, NaCl, SiO₂) was confirmed, providing abundant active sites and enhancing surface interactions. Batch adsorption studies demonstrated exceptional performance, achieving up to 98 % SY removal within only 5 minutes at neutral pH with a low dosage of 0.4 g. These findings highlight Ulva lactuca biochar as a low-cost, eco-friendly, and reusable adsorbent, offering a promising pathway for rapid and efficient remediation of dye-contaminated water.

Investigating seaweeds to identify their bioactive compounds for broader applications has gained significant importance. The present research aimed to evaluate the antibacterial activities of different extracts of Ulva lactuca. Gas chromatography-mass spectrometry (GC-MS) and Fourier transform infrared (FT-IR) were used to characterize the chemical constituents, while antibacterial activity was performed to confirm the biological potential of the extracts. FT-IR analysis of Ulva lactuca revealed the presence of valuable functional groups such as alkenes, phenols, aliphatic amines, alkanes, alcohols, carboxylic acids, and aromatic compounds. GC-MS analysis displayed distinct peaks indicating the presence of phytochemicals with various medicinal effects. The major identified components are neophytadiene (22.28%), linoleic acid (22.78%), Z, Z-2,28-heptagonalactonediene (12.46%), phytol (13.02%), and 1,2-benzenedicarboxylic acid (8.38%), among other bioactive compounds detected in methanol, chloroform, and hexane extracts. The three extracts were evaluated against seven bacterial strains, with Staphylococcus aureus and E. coli showing the highest sensitivity. These findings suggest that green seaweed extracts hold strong potential as natural and eco-friendly biocontrol agents, offering novel strategies for managing bacterial infections and improving microbial control practices in healthcare, agriculture, and environmental applications.