Search Results (42)

Antibacterial resistance has become a major problem where new promising drugs are needed. The extracts obtained from marine invertebrates Mytilus galloprovincialis, Patella sp., Gibbula sp. and Arbacia lixula were tested against bacteria using the disc diffusion method. Citrobacter sp. from seawater and Paenibacillus sp., Bacillus sp. and Geobacillus sp. from soil were used as well as the reference bacterial strains Staphylococcus aureus NCTC 12981, S. aureus subsp. aureus Rosenbach ATCC 6538, Salmonella enterica subsp. enterica serovar Enteritidis ATCC 13076, Salmonella enterica subsp. enterica serotype Typhimurium NCTC 12023, Listeria monocytogenes ATCC 19111, Klebsiella aerogenes ATCC 13048 and Escherichia coli NCTC 12241. The most successful bacterial inhibitors, inhibiting 8 of 13 strains were extracts of M. galloprovincialis, Patella sp., Gibbula sp., Enteromorpha sp., C. sinuosa and U. lactuca, extract of A. lixula showed antibacterial activity against five bacteria, while extract of C. officinalis showed no antibacterial activity. These results indicate the potential of these marine organisms as a source of antibacterial compounds and may serve as a basis for further research and development of new antibacterial agents. Full article

Mycosporine-like amino acids (MAAs) and glyceroglycolipids have promising applications in various fields, but limited research exists on their simultaneous extraction from macroalgae. This study optimized the key parameters (liquid–solid ratio, extraction temperature and extraction time) in the extraction of MAAs and glyceroglycolipids from Ecklonia kurome and Ulva lactuca using single factor and response surface experiments. The yields of MAAs from E. kurome and U. lactuca were 169.71 mg/g and 177.33 mg/g, respectively, while glyceroglycolipids were extracted from the residue with yields of 163.51 mg/g and 213.45 mg/g, respectively. Both extracts showed concentration-dependent antioxidant activities, with the MAAs extracted from U. lactuca demonstrating the strongest effect. The addition of MAA extract to flaxseed oil significantly reduced oxidation rancidity, highlighting its potential as a natural antioxidant for oils. The glyceroglycolipid extract from E. kurome exhibited significant moisture absorption, and a water-retaining agent prepared from this extract showed excellent moisture retention and resistance to high temperatures, freezing, and pressure. A silica gel column chromatography method confirmed the presence of MGDG in the purified glyceroglycolipid extract. These findings suggested that E. kurome and U. lactuca can be converted into high-value-added compounds with potential applications in food, cosmetics, and pharmaceuticals. Full article

Hypertension, type 2 diabetes (T2D), and obesity raise an individual’s risk of suffering from diseases associated with metabolic syndrome (MS). In humans, enzymes that play a role in the prevention and development of MS include angiotensin converting enzyme (ACE-1) associated with hypertension, α-amylase associated with T2D, and lipase linked to the development of obesity. Seaweeds are a rich source of bioactives consisting of proteins/peptides, polysaccharides, and lipids. This study examined the potential of seaweed-derived bioactives from Alaria esculenta, Ulva lactuca, and Palmaria palmata as inhibitors of ACE-1, α-amylase, and lipase. In vitro enzyme inhibitory assays were used to quantify the bioactivity of the seaweed extracts and compare their half-maximal inhibitory (IC₅₀) values to recognised positive control enzyme inhibitory drugs captopril© (an ACE-1 inhibitor), acarbose (an α-amylase inhibitor), and orlistat (a lipase inhibitor). Three seaweed extracts displayed enzyme inhibitory activities equal to, or more effective than, the reference positive control drugs. These were P. palmata peptides (ACE-1 IC₅₀ 94.29 ± 3.07 µg/mL, vs. captopril© 91.83 ± 2.68 µg/mL); A. esculenta polyphenol extract (α-amylase IC₅₀ 147.04 ± 9.72 µg/mL vs. acarbose 185.67 ± 12.48 µg/mL, and lipase IC₅₀ 106.21 ± 6.53 µg/mL vs. orlistat 139.74 ± 9.33 µg/mL); and U. lactuca polysaccharide extract (α-amylase IC₅₀ 168.06 ± 10.53 µg/mL vs. acarbose 185.67 ± 12.48 µg/mL). Proximate analysis also revealed that all three seaweeds were a good source of protein, fibre, and polyunsaturated essential fatty acids (PUFAs). These findings highlight the potential of these seaweeds in the management of diseases associated with MS and as foods. Full article

Seaweed presents a sustainable alternative source of valuable fatty acids (FAs) involving omega-3 (n-3) and omega-6 (n-6). As such, there is great potential to reduce pressure on wild fish populations, helping to combat overfishing and its associated global impacts. This study explored the effect of various environmental factors on the FA content and profile of Ulva lactuca using indoor photobioreactors. The taxonomic identity of U. lactuca was confirmed through DNA sequencing using 3 markers (rbcL, ITS, and tufa). The effects of temperature (8, 20, and 30 °C), seawater salinity (3.5, 3.0, 2.5, and 2.0% w/v), nutrient type and concentration (0 or 6.4 ppm, consisting of 50% w/w N-NO₃, 50% w/w N-NH₄, and 0–1 ppm P-PO₄), and irradiance (50, 100, and 150 μmol photons m⁻² s⁻¹) were evaluated. This study assessed their influence on U. lactuca’s biomass production rate (BPR), dry weight (DW), ash content (AC), and FA composition after 7 and 21 days. The results revealed that after 21 days, the polyunsaturated FA (PUFA) content decreased with the increasing seawater salinity (i.e., 38.9% ± 0.7, 33.8% ± 0.4, and 27.0% ± 0.4, and 6.6% ± 0.1 for a salinity of 2.0, 2.5, 3.0, and 3.5% w/v, respectively). The content of n-3 after 21 days increased significantly under the following conditions: 8 °C, a salinity of 2.5% w/v, 6.4 ppm of nitrogen without the addition of phosphorous, and an irradiation of 50 and 150 μmol photons m⁻² s⁻¹, affording a low n-6/n-3 proportion that fits a desirable level of an n6/n3 ratio (1–10) for a balanced nutritional diet. Full article

The continuous use of synthetic insecticides to suppress mosquito larvae has detrimental impacts on the environment and human health. Finding novel and target-specific bio-insecticides has become crucial. Here, the larvicidal and genotoxic activities of different extracts from Ulva lactuca and Turbinaria ornata toward Culex pipiens larvae were investigated. The macroalgae thalli were subjected to various solvent extractions followed by phytochemical quantification, larvicidal testing on C. pipiens larvae, genotoxic evaluation through comet assays, and compound characterization by gas chromatography–mass spectrometry. The methylene chloride extract from U. lactuca displayed the highest toxicity with LC₅₀ = 30.99 ppm, followed by the acetone extract from T. ornata, with LC₅₀ = 52.09 ppm after 72 h. U. lactuca exhibited the maximum contents of total alkaloids, total flavonoids, total terpenoids, total phenols, and total tannins with the methanol extract, while the acetone extract from T. ornata exhibited the maximum contents of total alkaloids, total flavonoids, total terpenoids, and total phenols. The methylene chloride extract of U. lactuca and the acetone extract of T. ornata caused significant DNA damage in larva body cells. Thus, the methylene chloride extract from U. lactuca and the acetone extract from T. ornata showed promising potential as environmentally friendly larvicides against C. pipiens larvae. Full article

The potential of the green macroalga Ulva lactuca is increasingly recognized, not only for its environmental benefits, but also for its applications in various industries, including food, pharmaceuticals, and cosmetics. Given this insight, a comprehensive analysis of the chemical profile of U. lactuca from the Adriatic Sea was carried out. The hydrodistillate, rich in (Z,Z,Z)-hexadeca-7,10,13-trienal and hexadecanoic acid, underlines its importance for health-related uses, particularly in lipid metabolism and cellular integrity. Fatty acid analysis showed a predominance of palmitic acid and a favorable n-6/n-3 polyunsaturated fatty acid ratio, suggesting that U. lactuca can make a valuable contribution to a balanced diet. In addition, essential amino acids, including leucine, valine, and isoleucine, support its use as a functional ingredient for muscle repair and metabolic health. The ethanol extract contained 56 compounds, including derivatives of fatty acids, phenolic acids, pigments, flavonoids, and steroids. Many of them, such as hexadecasphinganine, azelaic acid, 5-sulfosalicylic acid, and pheophytin a, have proven roles or potentials in promoting human health. These results confirm that U. lactuca is a rich source of bioactive compounds, emphasizing its potential in scientific research and its expanding industrial applications in health, nutrition, and cosmetics. Full article

To advance environmentally friendly technologies in the aquaculture of Atractoscion nobilis, and simultaneously to diversify seafood production, a 79-day trial was conducted to assess the performance of Ulva lactuca and Devaleraea mollis cultured in the effluent from A. nobilis in a land-based integrated multi-trophic aquaculture (IMTA) system in southern California, USA. Water quality and performance of macroalgae were measured weekly. The impacted factors on the growth of macroalgae and nutrient uptake rate of macroalgae were assessed. The specific growth rate of juvenile A. nobilis was 0.47–0.52%/d. Total ammonia nitrogen in effluents of A. nobilis tanks ranged from 0.03 to 0.19 mg/L. Ulva lactuca and D. mollis achieved an average productivity of 24.53 and 14.40 g dry weight (DW)/m²/d. The average nitrogen content was 3.48 and 4.89% DW, and accordingly, the average nitrogen uptake rate was 0.88 and 0.71 g/m²/d, respectively. Temperature and nutrient concentration were key factors impacting macroalgae growth, and light intensity also impacted the growth of D. mollis. The high protein content of U. lactuca and D. mollis would make them good for use as human or animal food, or for use in other industries. Research on the interaction effects between seawater exchange rates and aeration rates on the performance and nutrient uptake rates of macroalgae will be conducted in future studies. Full article

Macroalgal biomass blooms, including those causing the green and golden tides, have been rising along Chinese coasts, resulting in considerable social impacts and economic losses. To understand the links between the ongoing climate changes (ocean warming and acidification) and algal tide formation, the effects of temperature (20 and 24 °C), pCO₂ concentration (Partial Pressure of Carbon Dioxide, 410 ppm and 1000 ppm) and their interaction on the growth of Ulva prolifera and Ulva lactuca (green tide forming species), as well as Sargassum horneri (golden tide forming species) were investigated. The results indicate that the concurrent rises in temperature and pCO₂ level significantly boosted the growth and nutrient uptake rates of U. lactuca. For U. prolifera, the heightened growth and photosynthetic efficiency under higher CO₂ conditions are likely due to the increased availability of inorganic carbon. In contrast, S. horneri exhibited negligible responsiveness to the individual and combined effects of the increased temperature and CO₂ concentration. These outcomes indicate that the progressive climate changes, characterized by ocean warming and acidification, are likely to escalate the incidence of green tides caused by Ulva species, whereas they are not anticipated to precipitate golden tides. Full article

The sustainable meeting of the global quest for ruminant intensification dictates the need to identify alternative, eco-friendly, and safe feed ingredients. In this sense, macroalgae offer a new paradigm in sustainable ruminant feed supply. This study aimed to investigate the potential of sub-Antarctic macroalgae, including Lessonia flavicans, Macrocystis pyrifera, Gigartina skottbergii, and Ulva Lactuca, regarding their chemical composition, in vitro gas production, and CH₄ production. A completely randomized design consisted of a 96 h (h) incubation that included four different species and a control (alfalfa hay) with buffered rumen fluid. In vitro total gas, fermentation characteristics, and CH₄ production were evaluated. The highest and the lowest crude protein (CP) contents were for U. lactuca (185.9 g/kg) and G. skottsbergi (86 g/kg), respectively (p < 0.0001). All macroalage had lower levels of natural detergent fiber (NDF) and acid detergent fiber (ADF) compared to alfalfa hay (p < 0.0001). The highest potential of gas production (b) was for M. pyriphera (162.8 mL gas/g DM), followed by alfalfa (119.3 mL gas/g DM). However, G. skottsbergi and M. pyriphera showed the highest dry matter degradability at 96 h (68.49 and 67.62 mg/100 mg, respectively; p < 0.0001) and microbial crude protein (679.8 and 669.8 mg/g, respectively, p < 0.0001). All four tested algae produced lower amounts of methane compared to alfalfa hay (p < 0.0001). After 24 h of incubation, M. pyriphera, L. flavicons, G. skottsbergi, and U. lactuca reduced CH₄ by 99.7%, 98.6%, 92.9%, and 79.8%, respectively, when compared with the control. Also, all tested algae had lower (p = 0.0001) CH₄ production (ml CH₄/g Dry matter degradability, DMD) than alfalfa hay. The current results suggest that M. pyriphera and L. flavicons are promising feed additives for ruminants with eco-friendly production and acceptable CP content and DMD that could effectively mitigate CH₄ emissions. Overall, these findings suggest that macroalgae hold promise as a substitute feed source for sustaining ruminant production at the onset of global warming. Full article

This study aimed to biosynthesize zinc oxide nanoparticles (ZnO-NPs) using extracts from various seaweeds, including Ulva lactuca, Ulva intestinalis (Chlorophyta), and Sargassum muticum (Phaeophyceae). The biosynthesized ZnO-NPs were characterized using UV spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, transmission electron microscopy, and zeta potential analysis. Their antimicrobial activity was assessed using the disk diffusion method, revealing significant efficacy against two bacterial species (Klebsiella pneumoniae and Escherichia coli) and two fungal species (Candida albicans and Aspergillus niger). Additionally, the antioxidant potential of the ZnO-NPs was evaluated based on the total antioxidant capacity, ferric reducing antioxidant power, and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assays. The antioxidant activity of the ZnO-NPs was confirmed using the three antioxidant assays. The ZnO-NPs of U. lactuca recorded the highest antioxidant activity. The cytotoxicity of the ZnO-NPs was tested on different cell lines using the MTT assay. The ZnO-NPs of U. lactuca showed very weak cytotoxic effects on WI 38 (84.98 ± 4.6 µg/mL) and 23, and this result confirmed its safety on normal cells. The ZnO-NPs of U. lactuca showed moderate cytotoxic effects on the HepG-2 (46.66 ± 2.8 µg/mL) and MCF-7 (30.60 ± 2.1 µg/mL) cell lines. In an in vivo study, the ZnO-NPs of U. lactuca showed a decrease in tumor volume, weight, and serum malondialdehyde in experimental mice, while the total antioxidant capacity of the serum was increased. Histopathological changes in ZnO-NPs indicated a reduction in tumor size, a lower number of mitosis divisions, and a rise in apoptosis correlated with the ZnO-NPs of the U. lactuca-treated groups. In conclusion, biosynthesized ZnO-NPs from seaweed showed potent antimicrobial, antioxidant, and antitumor activities, which can be used in the pharmaceutical industry. Full article

Macroalgae seaweeds such as Ulva lactuca and Gracilaria verrucosa cause problems on the northern coast of the Italian Adriatic Sea because their overabundance hinders the growth of cultivated clams, Rudatapes philippinarum. This study focused on the green synthesis of CuO nanoparticles from U. lactuca and G. verrucosa. The biosynthesized CuO NPs were successfully characterized using FTIR, XRD, HRTEM/EDX, and zeta potential. Nanoparticles from the two different algae species are essentially identical, with the same physical characteristics and almost the same antimicrobial activities. We have not investigated the cause of this identity, but it seems likely to arise from the reaction of Cu with the same algae metabolites in both species. The study demonstrates that it is possible to obtain useful products from these macroalgae through a green synthesis approach and that they should be considered as not just a cause of environmental and economic damage but also as a potential source of income. Full article

In this research, the chemical compositions of various extracts obtained from Ulva lactuca, a type of green seaweed collected from the Nador lagoon in the northern region of Morocco, were compared. Their antioxidant and anti-diabetic properties were also studied. Using GC–MS technology, the fatty acid content of the samples was analyzed, revealing that palmitic acid, eicosenoic acid, and linoleic acid were the most abundant unsaturated fatty acids present in all samples. The HPLC analysis indicated that sinapic acid, naringin, rutin, quercetin, cinnamic acid, salicylic acid, apigenin, flavone, and flavanone were the most prevalent phenolic compounds. The aqueous extract obtained by maceration showed high levels of polyphenols and flavonoids, with values of 379.67 ± 0.09 mg GAE/g and 212.11 ± 0.11 mg QE/g, respectively. This extract also exhibited an impressive ability to scavenge DPPH radicals, as indicated by its IC₅₀ value of 0.095 ± 0.12 mg/mL. Additionally, the methanolic extract obtained using the Soxhlet method demonstrated antioxidant properties by preventing β-carotene discoloration, with an IC₅₀ of 0.087 ± 0.14 mg/mL. Results from in-vitro studies showed that extracts from U. lactuca were able to significantly inhibit the enzymatic activity of α-amylase and α-glucosidase. Among the various extracts, methanolic extract (S) has been identified as the most potent inhibitor, exhibiting a statistically similar effect to that of acarbose. Furthermore, molecular docking models were used to evaluate the interaction between the primary phytochemicals found in these extracts and the human pancreatic α-amylase and α-glucosidase enzymes. These findings suggest that U. lactuca extracts contain bioactive substances that are capable of reducing enzyme activity more effectively than the commercially available drug, acarbose. Full article

This study focused on evaluating the effect of different concentrations of nutrients and total suspended solids on the removal rate of nutrients and biocompounds from the macroalgae U. lactuca in an integrated system with the shrimp Penaeus vannamei in biofloc. The experiment lasted 45 days and included five treatments with three replicates each, with percentages of 0 (control), 25, 50, 75, and 100% biofloc inoculum (73.3 ± 5.7 and 325.0 ± 21.2 mg L⁻¹ initial nitrate and solids, respectively, in the 100% inoculum), from a shrimp farm, resulting in different concentrations of solids and nutrients. The macroalgae were introduced into 280 L tanks at a density of 0.88 kg m⁻², along with 200 shrimp m⁻³. The algae were separated by a floating structure. Water quality parameters were measured, and the nutrient removal rate was evaluated. The treatment with 75% inoculum showed a removal rate of 55.0 ± 4.0 and 31.0 ± 10.0% of nitrate and phosphate, respectively. There was no difference in macroalgae growth between the treatments; however, macroalgae grown in 75% inoculum had higher protein, chlorophyll-a, and lower ash values compared with the control. The use of macroalgae in integrated production with shrimp under the conditions of the treatment with 75% biofloc inoculum proved to be viable and sustainable. Full article

Marine algal extracts exhibit a potent inhibitory effect against several enveloped and non-enveloped viruses. The infection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has several adverse effects, including an increased mortality rate. The anti-COVID-19 agents are still limited; this issue requires exploring novel, effective anti-SARS-CoV-2 therapeutic approaches. This study investigated the antiviral activity of an aqueous extract of Ulva lactuca, which was collected from the Gulf of Suez, Egypt. The aqueous extract of Ulva lactuca was characterized by high-performance liquid chromatography (HPLC), Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Energy Dispersive X-ray (EDX) analyses. According to the HPLC analysis, the extract comprises several sugars, mostly rhamnose (32.88%). The FTIR spectra showed numerous bands related to the functional groups. EDX analysis confirmed the presence of different elements, such as oxygen (O), carbon (C), sulfur (S), magnesium (Mg), potassium (K), calcium (Ca), and sodium (Na), with different concentrations. The aqueous extract of U. lactuca (0.0312 mg/mL) exhibited potent anti-SARS-CoV-2 activity via virucidal activity, inhibition of viral replication, and interference with viral adsorption (% inhibitions of 64%, 33.3%, and 31.1%, respectively). Consequently, ulvan could be a promising compound for preclinical study in the drug development process to combat SARS-CoV-2. Full article

The important purpose of this work is to evaluate the biostimulant activity of the algae Chlorella vulgaris and Ulva lactuca extracts on the crop plants Lactuca sativa, to compare the effect of these two green algae on plant growth and development as a part of a sustainable plant production method and show that these extracts can be a promissory source for replacing chemical fertilization. The study faces all the phases of plant growth, from the germination of the seeds to the greenhouse plant growth and treatment, matched with the chemical characterization of both the green algae used and the lettuce plants. This work is meant to define a tool to be improved by more experiments and studies in order to suggest a sustainable method that could ensure an adequate use of organic fertilizer. After the identification of the best concentration of the respective extracts of C. vulgaris and U. lactuca, the experiment affirmed that a low concentration (15% C. vulgaris and 25% U. lactuca) of the extracts contributed to the production of plants with a satisfying nutritional profile, while a high concentration (75% U. lactuca) is conducive to lettuce production with some parameters not suitable for human diet and health. Full article