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Due to the global COVID-19 pandemic, there is a need to screen for novel compounds with antiviral activity against SARS-COV-2. Here we compared chemical composition and the in vitro anti- SARS-COV-2 activity of two different Ulva sp. crude ulvan extracts: one obtained by an HCl-based and another one by ammonium oxalate-based (AOx) extraction protocols. The composition of the crude extracts was analyzed and their antiviral activity was assessed in a cytopathic effect reduction assay using Vero E6 cells. We show that the extraction protocols have a significant impact on the chemical composition, anti- SARS-COV-2 activity, and cytotoxicity of these ulvan extracts. The ulvan extract based on the AOx protocol had a higher average molecular weight, higher charge, and 11.3-fold higher antiviral activity than HCl-based extract. Our results strongly suggest that further bioassay-guided investigation into bioactivity of compounds found in Ulva sp. ulvan extracts could lead to the discovery of novel anti-SARS-CoV-2 antivirals.

Ulva sp. is known to be a source of bioactive compounds such as ulvans, but their biological activity on human dermal fibroblast extracellular matrix (ECM) is poorly reported. In this work, the regulation of ECM has been investigated for the first time at both proteomic and transcriptomic levels in normal human skin dermal fibroblasts, after 48 h of incubation with poly- and oligosaccharide fractions from Ulva sp. obtained after enzyme-assisted extraction and depolymerization. Cell proliferation enhancement (up to +68%) without exhibiting any cytotoxic effect on fibroblasts was demonstrated at 50 and 1000 µg/mL by both fractions. At the proteomic level, polysaccharide fractions at 1000 µg/mL enhanced the most the synthesis of glycosaminoglycans (GAGs, up to +57%), total collagen, especially types I (up to +217%) and III, as well as the synthesis and activity of MMP-1 (Matrix Metalloproteinase-1, up to +309%). In contrast, oligosaccharide fractions had no effect on GAGs synthesis but exhibited similarities for collagens and MMP-1 regulation. At the transcriptomic level, the decrease of COL1A1 and COL1A2 expression, and increase of COL3A1 and MMP-1 expression, confirmed the modulation of ECM metabolism by both fractions. Our research emphasizes that poly- and oligosaccharide Ulva sp. fractions exhibit interesting biological activities and supports their potential use in the area of skin renewal for anti-aging dermo-cosmetic applications.

The species of green macroalga belonging to the genus Ulva (family: Ulvaceae) are utilized in various fields, from food supplements to biomedical applications. Ulvan, a polysaccharide obtained from various Ulva species, has shown various biological activities, including antioxidant, anti-inflammatory, anticancer, antibacterial, and antiviral activities. To obtain the polysaccharide ulvan that can be utilized in various fields, it is necessary to understand the critical points that affect its physicochemical nature, the extraction procedures, and the mechanism of action for biological activities. This article discusses the physicochemical properties, extraction, isolation and characterization procedures and benefits in food and biomedical applications of ulvan. In conclusion, ulvan from Ulva sp. has the potential to be used as a therapeutic agent and also as an additional ingredient in the development of tissue engineering procedures.

The impact of air-drying at 25 &deg, C, brining at 25%, and dry-salting (at 28% and 40%) on the quality and nutritional parameters of Ulva rigida were evaluated over six months of storage. Overall, the main changes occurred in physical aspects during storage time, with U. rigida intensifying its yellow/browning tones, which were more evident in salt-treated samples. The force necessary to fracture the seaweed also increased under all the preservative conditions in the first month. Conversely, the nutritional parameters of U. rigida remained stable during the 180 days of storage. All processed samples showed a high content of insoluble and soluble fibers, overall accounting for 55%&ndash, 57% dw, and of proteins (17.5%&ndash, 19.2% dw), together with significant amounts of Fe (86&ndash, 92 mg/kg dw). The total fatty acids pool only accounted for 3.9%&ndash, 4.3% dw, but it was rich in unsaturated fatty acids (44%&ndash, 49% total fatty acids), namely palmitoleic (C16:1), oleic (C18:1), linoleic (C18:2), linolenic (C18:3), and stearidonic (18:4) acids, with an overall omega 6/omega 3 ratio below 0.6, a fact that highlights their potential health-promoting properties.

This chapter focuses on the bioprospecting of macro algae species in the Arabian Gulf, Abu Dhabi coast. Three species of macro algae were collected and subjected for detailed analysis and determination of biogas potentials, Padina boergesenii, Colpomenia sinuosa, and Ulva sp. Composition analysis and elemental analysis were used to determine bioenergy potentials. Anaerobic digestion of the three macro algae samples was carried out at two different volatile solid loadings (0.2 and 0.5%). The results showed significant methane yield for all three species, with Ulva sp. yielding higher methane production compared to Padina boergesenii and Colpomenia sinuosa. Biogas production for Ulva sp. was furthermore carried out at 1%, 3%, and 5% VS loading. The highest specific methane production for Ulva sp. was observed with 1% VS reaching 223 mlCH4/gVS in 27 days. This chapter focuses on the bioprospecting of macro algae species in the Arabian Gulf, Abu Dhabi coast. Three species of macro algae were collected and subjected for detailed analysis and determination of biogas potentials, Padina boergesenii, Colpomenia sinuosa, and Ulva sp. Composition analysis and elemental analysis were used to determine bioenergy potentials. Anaerobic digestion of the three macro algae samples was carried out at two different volatile solid loadings (0.2 and 0.5%). The results showed significant methane yield for all three species, with Ulva sp. yielding higher methane production compared to Padina boergesenii and Colpomenia sinuosa. Biogas production for Ulva sp. was furthermore carried out at 1%, 3%, and 5% VS loading. The highest specific methane production for Ulva sp. was observed with 1% VS reaching 223 ml_CH4/gVS in 27 days.

In the fermentation and bioenergy industry, terrestrial biomass is usually fractionated and the collected components, such as starch, are processed separately. Such a separation has not been reported for seaweeds. In this work, the direct hydrothermal processing of the whole green seaweed Ulva sp. biomass is compared to processing of separated starch and cellulose, to find the preferable route for monosaccharide, hydrochar, and polyhydroxyalkanoates (PHA) production. Glucose was the major released monosaccharide. A significant share of the glucose yield comes from the starch fraction. The highest hydrochar yield with the lowest ash content was obtained from the separated cellulose fraction. The highest PHA yield was obtained using a whole Ulva sp. hydrolysate fermentation with Haloferax mediterranei. Economic analysis shows the advantage of direct Ulva sp. biomass fermentation to PHA. The co-production of glucose and hydrochar does not add significant economic benefits to the process under plausible prices of the two outputs.

WOS: 000290040000032, Ulva gigantea (Kutzing) bliding (UGB) obtained from sea inlet of Izmir-Turkey has been studied as a biosorbent for removal of radioactive metals from water. In this study, unmodified UGB and modified UGB with glutaraldehyde (GUGB) characterized by FTIR spectroscopy were used as biosorbents for removal of U(VI) and Th(IV) ions from aqueous solution. Adsorption experiments performed under batch process with initial pH, contact time, adsorbent mass and temperature as variables. In order to determine the adsorption characteristics, Langmuir, Freundlich and Dubinin-Raduschkevich adsorption isotherms were applied to the adsorption data. Adsorption experiments showed that the adsorption isotherms correlated well with the Freundlich model. The sorption followed pseudo-second-order kinetics. The thermodynamic parameters such as variations of Delta HA degrees, Delta GA degrees and Delta SA degrees were estimated as a function of temperature. The thermodynamics of the adsorption of U(VI) and Th(IV) onto UGB and GUGB indicates that the spontaneous and exothermic nature of the process. The results showed that UGB and GUGB were potential for application in removal of U(VI) and Th(IV) from aqueous solution.

In an attempt to correlate external levels of exposure, bioaccumulation markers and oxidative stress responses in the green macroalgae Ulva sp., an investigative biomonitoring study was performed in a Portuguese coastal lagoon with a complex contamination scenario (eutrophication and moderate metal levels). Ulva sp. was collected seasonally in three stations: BB (Barrosa branch) and BS (Bom-Sucesso branch) located in confined areas of the upper lagoon; LL (lower lagoon) closer to the lagoon inlet and selected as reference station. Water and sediment were both monitored for metals (Mn, Cu, Cr, Ni, Cd). Additionally, nutrients and organic matter were measured in water and sediment, respectively. Catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), glutathione-S-transferase (GST), total glutathione (GSH(t)) and lipid peroxidation (LPO), as well as Mn, Cu, Cr, Ni and Cd were measured in the algae. Metal levels in Ulva sp. consistently reflected their occurrence in water. Ulva sp. from BB exhibited higher CAT activity (autumn and spring) in agreement with Cu and Ni increases in water and algae and supported by significant Pearson correlations. The involvement of GPx on algal defences was considered since a positive correlation was observed with accumulated Mn. At BB, a direct implication of accumulated metals on increases of GR (autumn) and GSH(t) (summer) was also assumed. The contribution of GST to algal defences seemed to be less prominent. Despite the enzymatic antioxidant activation at BB, Ulva sp. collected in autumn and spring did not show efficient coping with ROS overproduction as LPO occurred. Globally, the adopted multi-biomarker approach coupled with environmental chemical characterization, pointed out BB as a major impacted area. The integration of oxidative stress responses into a general stress index (IBR) substantiated the data interpretation, providing a more definitive identification of the level of pollution, and therefore contributing to the understanding of cause-effect relationships.

Ulva spp., the algae most responsible for green tides in Brittany (France), are found on the foreshore and in the most beachward wave area (MBWA) of many bays during green tide phenomena. These algae have recently been seen drifting at greater depths (reaching -20 m). In view of the significant quantities of algae found at these depths, and the less favorable conditions for algal growth than in the intertidal zone, we attempted to determine if they could grow there. For that, during their maximum growth period (from May to July), algae were picked up at three stations located on the foreshore, in the MBWA and in the subtidal (deep) zones of the Bay of Douarnenez, and their nitrogen, carbon and chlorophyll a+b contents were determined, and their photosynthetic activity was compared in the laboratory. The intracellular concentrations did not differ much from one station to another, although in the subtidal zone, the irradiance and the nitrogen concentration in the ambient water were much lower than those measured on the foreshore and in the MBWA. Photosynthetic activity characterized by maximum amounts of oxygen produced at different irradiances and by saturating and compensating irradiance levels, was also quite similar at the three stations. The irradiance, temperature and salinity of the subtidal environment, together with the chemical and photosynthetic characteristics of the algae found in that area, are consistent with the hypothesis that they grow there, and that their nitrogen supply comes from nitrogen releases from sediments. Nevertheless, their growth rate is probably less than that of algae in the MBWA. (C) 2007 Elsevier B.V. All rights reserved.

This study was conducted to determine heavy metal levels in macroalgae (Ulva sp. and Enteromorpha sp.) on four beach heavily used by the people in the province of Mersin, for this purpose; Aluminum (Al), chromium (Cr), manganese (Mn), iron (Fe), nickel (Ni), copper (Cu), zinc (Zn), lead (Pb) and cadmium (Cd) levels were determined on a monthly basis. The results showed that the highest accumulation of heavy metals in algae were detected at station 1 with Cu and Zn, at station 2 with Cd and at station 4 with Al, Mn, Fe and Ni. Accumulation levels of heavy metals have been detected in the order Fe>Al>Mn>Ni>Zn> Cr>Cu>Pb>Cd; Fe>Al>Ni>Mn>Zn>Cr>Cu>Pb>Cd and Fe>Al>Mn>Ni>Cr>Zn>Pb>Cd> Cu in Ulva sp, in Enteromorpha sp. and in sediment samples respectively.