Using biosorption to enrich the biomass of seaweeds from the Baltic Sea with microelements to produce mineral feed supplement for livestock

Approaches, challenges and prospects for modeling macroalgal dynamics in the green tide: The case of Ulva prolifera

Ulva prolifera blooms, also known as green tides, significantly disrupt coastal ecosystems by altering species balance, energy flow, and nutrient cycling. These blooms, driven by nutrient enrichment, climate change, and human activities, have become a pressing environmental challenge in coastal regions. This review synthesizes current advances in modeling the growth, dispersal, and decline of U. prolifera blooms, emphasizing the roles of environmental drivers such as nutrient availability, temperature, light, and hydrodynamic conditions. We discuss empirical and mechanistic modeling approaches, highlighting their applications, limitations, and potential for predicting bloom dynamics. Special attention is given to model calibration, validation, and the integration of remote sensing and environmental data, which are crucial for ensuring model accuracy and reliability. Despite significant progress, challenges remain in addressing data gaps, incorporating climate variability, and simulating complex ecological interactions. Future research directions include the development of multi-scale, coupled models and the integration of socio-economic impacts to enhance bloom management strategies and inform policy development. The insights presented are intended to advance the understanding of U. prolifera bloom dynamics and contribute to the mitigation of their ecological and socio-economic impacts.

Application of the brown macroalga Saccharina latissima (Laminariales, Phaeophyceae) as a feed ingredient for livestock: A review

In recent years, marine macroalgae have been recognized as potential alternative and sustainable feeding resources for livestock. Differences in nutritional values and biomass yield across macroalgal species are critical factors while aiming to utilize them as animal feed components. A brown macroalga, Saccharina latissima, also known as sugar kelp, has a promising biomass yield and high nutritional and bioactive compounds that can benefit both ruminant and monogastric animals. For example, the dietary inclusion of S. latissima in dairy and beef cattle can enhance milk yield, meat quality, and iodine content in milk and meat while reducing enteric methane emissions in vitro. However, high iodine content and the presence of some potentially toxic elements (arsenic, cadmium, etc.) lead to critical challenges, demanding careful consideration while determining the inclusion level of S. latissima in the livestock feed. To address these challenges, effective post-harvest biomass processing techniques, particularly hydrothermal treatments, have shown promise in reducing heavy metals and minerals of concern (e.g., iodine) and enhancing their safety as animal feed. It is thus essential to evaluate the sustainability of post-harvest processing techniques as they are usually energy-demanding and can negatively influence nutrient utilization in animals as certain digestible fractions can disappear during processing. Furthermore, variations in the nutritional and bioactive composition of S. latissima due to seasonal and spatial factors can create challenges for commercial exploitation. In this context, multiple harvesting of biomass and choosing the appropriate harvesting seasons can maximize the nutritional potential of S. latissima. In conclusion, S. latissima can be a novel feed ingredient for livestock, but year-round biomass availability and identifying cost-effective and energy-efficient post-harvest biomass processing methods that optimize both nutritional values and digestibility of S. latissima are critical for improving animal production, performance, and health.

WITHDRAWN: Unlimited possibilities to use Сladophora (Chlorophyta, Ulvophyceae, Cladophorales) biomass in agriculture and aquaculture with profit for the environment and humanity

This article has been withdrawn: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/policies/article-withdrawal). This article has been withdrawn at the request of the Publisher for legal reasons related to Elsevier's policy on Geographic Sanctions (https://www.elsevier.com/about/policies/trade-sanctions).

Pros and cons of Ulva lactuca and Cladophora glomerata grown in freshwater as feed

The use of algae as alternative feeds has long time attracted interest. However, due to excessive accumulation and variation in some of its components, difficulty in harvesting, and the need for some processes (cleaning, rinsing, drying, etc.) before final use, it causes hesitations about their use as feed. The feed values of Ulva lactuca and Cladophora glomerata collected from the same region in two different years (2020-2021) were investigated. The comparison of Ulva lactuca and Clodophora glomerata in two successive yearsyielded significant differences (P < 0.05) for crude protein% (22.23-10.78 and 18.38-12.85), crude ash% (19.28-34.10 and 40.67-35.51), ADF% (13.41-12.39 and 19.61-22.13), NDF% (39.18-36.35 and 29.36-35.74), calcium% (11.75-1.49 and 38.47-1.35), magnesium% (1.02-13.54 and 1.76-8.61), potassium% (0.53-6.17 and 1.50-17.86), sulphur% (4.76-2.41 and 3.41-1.80), and nickel ppm (9.50-87.5 and 20.25-105.3). Significant differences were also detected between other nutrients, minerals, energy, and digestibility values (P < 0.05). It has been determined that some heavy metal and mineral amounts are at restrictive levels at the point of use as feed. Aluminum (4982.7-7459.3 ppm) and silicon (8882.3-1449.3 ppm) were found in Ulva lactuca and Cladophora glomerata, respectively (P < 0.05). Sulphur, aluminum, silicon, and nickel amounts are above the tolarable feed criteria limits. Cadmium and lead were determined to be above the limits allowed in the legal legislation. Their biosorbent properties cause them to be affected by the ecosystem, and undesirable accumulations appear as a restrictive situation. Therefore, it is necessary to systematically determine their contents and variations. It was concluded that they are important in terms of potential feed value but should be used in a controlled manner.

Cu phytoextraction and biomass utilization as essential trace element feed supplements for livestock

Copper (Cu), as an essential element, is added to animal feed to stimulate growth and prevent disease. The forage crop alfalfa (Medicago sativa L.) produced during Cu phytoextraction may be considered a biofortified crop to substitute the Cu feed additives for livestock production, beneficially alleviating Cu contamination in soils and reducing its input into agriculture systems. To assess this, alfalfa was grown in three similar soils with different Cu levels, i.e., 11, 439 and 779 mg kg^-1 for uncontaminated soil (A), moderately Cu-contaminated soil (B) and highly Cu-contaminated soil (C), respectively. EDDS (Ethylenediamine-N,N'-disuccinic acid) was applied to the soils seven days before the first cutting at four rates (0, 0.5, 2 and 5 mmol kg^-1) to enhance bioavailable Cu uptake. Alfalfa grew well in soils A and B but not in the highly Cu-contaminated soil. After applying EDDS, a significant biomass reduction of the first cutting shoot was only observed with 5 mmol kg^-1 EDDS in the highly Cu-contaminated soil, with a 45% (P < 0.05) decrease when compared to the control. Alfalfa grown in the three soils gradually wilted after the first cutting with 5 mmol kg^-1 EDDS, and Cu concentrations in the first cutting shoot were augmented strongly, by 250% (P < 0.05), 3500% (P < 0.05) and 6700% (P < 0.05) compared to the controls, respectively. Cu concentrations in alfalfa shoots were found to be higher in this study than in some fodder plants and further augmented in soils with higher Cu levels and with EDDS application. These findings suggest that alfalfa grown on clean soils or soils with up to 450 mg Cu kg^-1 (with appropriate EDDS dosages) has the potential to be considered as a partial Cu supplementation for livestock. This research laid the foundation for the integration between Cu-phytoextraction and Cu-biofortification for livestock.

Lemna minor Cultivation for Treating Swine Manure and Providing Micronutrients for Animal Feed

The potential of Lemna minor to valorise agricultural wastewater into a protein-rich feed component to meet the growing demand for animal feed protein and reduce the excess of nutrients in certain European regions was investigated. Three pilot-scale systems were monitored for nine weeks under outdoor conditions in Flanders. The systems were fed with a mixture of the liquid fraction and the biological effluent of a swine manure treatment system diluted with rainwater in order that the weekly N and P addition was equal to the N and P removal by the system. The design tested the accumulation of elements in a continuous recirculation system. Potassium, Cl, S, Ca, and Mg were abundantly available in the swine manure wastewaters and tended to accumulate, being a possible cause of concern for long-operating recirculation systems. The harvested duckweed was characterised for its mineral composition and protein content. In animal husbandry, trace elements are specifically added to animal feed as micronutrients and, thus, feedstuffs biofortified with essential trace elements can provide added value. Duckweed grown on the tested mixture of swine manure waste streams could be considered as a source of Mn, Zn, and Fe for swine feed, while it is not a source of Cu for swine feed. Moreover, it was observed that As, Cd, and Pb content were below the limits of the feed Directive 2002/32/EC in the duckweed grown on the tested medium. Overall, these results demonstrate that duckweed can effectively remove nutrients from agriculture wastewaters in a recirculated system while producing a feed source with a protein content of 35% DM.

Zn phytoextraction and recycling of alfalfa biomass as potential Zn-biofortified feed crop

Zn is an essential micronutrient for living organisms and, in that capacity, it is added to animal feed in intensive livestock production to promote growth and eliminate diseases. Alfalfa (Medicago sativa L.) may have the potential to compensate and substitute the need for chemical Zn additives in feeds as a Zn-biofortified feed crop when grown on Zn-enriched soils. Thus, this possibility was investigated with a greenhouse experiment using three soils with Zn concentrations (mg kg^-1) of 189 (soil A), 265 (soil B) and 1496 (soil C). Ethylenediamine-N,N'-disuccinate acid (EDDS) and Nitrilotriacetic acid (NTA) at different rates (0 as control, 0.5, 2 and 5 mmol kg^-1) were applied as soil additives to enhance the phytoextraction efficiency of alfalfa. The results showed that Zn was highly transferable in alfalfa tissues in the three soils even without additives. EDDS was more effective than NTA in enhancing Zn phytoextraction by alfalfa. The maximum Zn accumulation in the third cutting shoots was obtained with the EDDS concentration of 5 mmol kg^-1 in soil A and of 2 mmol kg^-1 in soil B, with a 462% and 162% increase compared with controls, respectively. However, the higher EDDS concentration resulted in a significant reduction in biomass production. In soil C, all EDDS concentrations resulted in similar Zn accumulations in the third shoot. To improve the phytoextraction efficacy of Zn while minimizing its phytotoxicity on alfalfa, the rate of 2 mmol kg^-1 EDDS proved to be optimal for soil B, and 0.5 mmol kg^-1 EDDS for soils A and C. Findings suggest that phytoextraction of Zn-enriched soil can be combined with Zn biofortification, thus allowing to recycle Zn into biomass that can, to an extent, substitute Zn feed additives. This study provided a primary data set for the combination of Zn-biofortification and Zn-phytoextraction.

From ecosystems to socio-economic benefits: A systematic review of coastal ecosystem services in the Baltic Sea

Seagrass meadows, algal forests and mussel beds are widely regarded as foundation species that support communities providing valuable ecosystem services in many coastal regions; however, quantitative evidence of the relationship is scarce. Using the Baltic Sea as a case study, a region of significant socio-economic importance in the northern hemisphere, we systematically synthesized the primary literature and summarized the current knowledge on ecosystem services derived from seagrass, macroalgae, and mussels (see animated video summary of the manuscript: Video abstract). We found 1740 individual ecosystem service records (ESR), 61% of which were related to macroalgae, 26% to mussel beds and 13% to seagrass meadows. The most frequently reported ecosystem services were raw material (533 ESR), habitat provision (262 ESR) and regulation of pollutants (215 ESR). Toxins (356 ESR) and nutrients (302 ESR) were the most well-documented pressures to services provided by coastal ecosystems. Next, we assessed the current state of knowledge as well as knowledge transfer of ecosystem services to policies through natural, social, human and economic dimensions, using a systematic scoring tool, the Eco-GAME matrix. We found good quantitative information about how ecosystems generated the service but almost no knowledge of how they translate into socio-economic benefits (8 out of 657 papers, 1.2%). While we are aware that research on Baltic Sea socio-economic benefits does exist, the link with ecosystems providing the service is mostly missing. To close this knowledge gap, we need a better analytical framework that is capable of directly linking existing quantitative information about ecosystem service generation with human benefit.

Comparative assessment of trace element accumulation and biomonitoring in seaweed Ulva lactuca and seagrass Posidonia oceanica

The present research compared the capability of the green seaweed Ulva lactuca and the seagrass Posidonia oceanica to accumulate and biomonitor the levels of six trace elements: Cd, Cr, Cu, Ni, Pb, Zn. The concentrations of these elements were analyzed in seawater, bottom sediments, U. lactuca thalli and P. oceanica leaves, in four sites of Sicily (Italy) with different levels of pollution. The results showed that P. oceanica is able to accumulate greater concentrations of trace elements compared to U. lactuca. Both species, instead, acted equally as good bioindicators of marine pollution, showing significant correlations with the levels of trace elements in the surrounding environment. The use of P. oceanica and U. lactuca as bioindicators is still limited in biomonitoring programs, and should be further encouraged given the ever-increasing marine pollution.

The alga Ulva lactuca (Ulvaceae, Chlorophyta) as a bioindicator of trace element contamination along the coast of Sicily, Italy

The marine environment is subjected to ever-increasing levels of contamination, especially along the coastal areas with urban and industrial activities. Consequently, monitoring campaigns on large scales should be conducted on a regular basis for a better management of marine ecosystems. This study tested the capacity of the green alga Ulva lactuca to act as a bioindicator of trace elements along the coasts of Sicily (Italy). The concentrations of the metals Cd, Cr, Cu, Ni, Pb and Zn were analyzed in samples of water, sediments and U. lactuca thalli, which were collected in ten different sites at diverse levels of human impact. The results showed that U. lactuca can accumulate essential and non-essential elements at similar concentrations. The analysis of trace elements showed also that the metal content in U. lactuca is significantly correlated with the levels of trace elements in water and sediments. U. lactuca fits numerous features that make it one of the best bioindicators of marine pollution, also thanks to its worldwide distribution and capacity to accumulate trace elements under toxic conditions. The use of U. lactuca should be encouraged to set up large-scale monitoring programs, especially in highly impacted seas like the Mediterranean where U. lactuca is widespread.

Freshwater green macroalgae as a biosorbent of Cr(III) ions

The research was conducted to evaluate the possibility of using algae enriched with Cr(III) ions as a feed additive for horses. As a sorbent, macroalgaCladophora glomeratawas chosen. The results of the kinetic and equilibrium experiments on biosorption of Cr(III) ions are presented. The pseudo-second order model was used for the description of kinetics. Equilibrium of biosorption process was described by Langmuir model. The effect of biosorbent dose: 0.1–1.0 g·L-1, initial metal ions concentration: 100–300 mg·L-1and pH: 3–5 on the biosorption capacity in a batch system was evaluated. These factors played a significant role in affecting the biosorption capacity of biosorbent and the rate constant. Optimal pH for biosorption was 5, biosorbent dose 0.1 g·L-1, initial concentration of Cr(III) ions 300 mg·L-1. The maximum biosorption capacity determined from Langmuir equation was 107.5 mg·g-1(forCS1.0 g·L-1, pH 5). The experiments were also performed in a column system and they showed that almost 100% of Cr(III) ions were absorbed after 200 minutes. The FTIR and SEM-EDX technique confirmed binding of Cr(III) ions by the algal biomass. Due to very good biosorption properties,Cladophora glomeratacan be considered as a carrier of microelement ions in animal feeding.

The application of biosorption for production of micronutrient fertilizers based on waste biomass

In the present paper, new environmental-friendly fertilizer components were produced in biosorption process by the enrichment of the biomass with zinc, essential in plant cultivation. The obtained new preparations can be used as controlled release micronutrient fertilizers because microelements are bound to the functional groups present in the cell wall structures of the biomass. It is assumed that new fertilizing materials will be characterized by higher bioavailability, gradual release of micronutrients required by plants, and lower leaching to groundwater. The biological origin of the material used in plant fertilization results in the elimination of toxic effect towards plants and groundwater mainly caused by low biodegradability of fertilizers. Utilitarian properties of new formulations enable to reduce negative implications of fertilizers for environmental quality and influence ecological health. In this work, the utilitarian properties of materials such as peat, bark, seaweeds, seaweed post-extraction residues, and spent mushroom substrate enriched via biosorption with Zn(II) ions were examined in germination tests on Lepidium sativum. Obtained results were compared with conventional fertilizers—inorganic salt and chelate. It was shown that zinc fertilization led to biofortification of plant in these micronutrients. Moreover, the mass of plants fertilized with zinc was higher than in the control group.

Biotechnological potential of the seaweed Cladophora rupestris (Chlorophyta, Cladophorales) lipidic extract

Recently, with the advent of modern technologies, various marine organisms including algae are being studied as sources of natural substances effective on classical microorganisms and able to also combat the new trend of acquired resistance in microbes. In the present study the antimicrobial activity of the lipidic extract of the green seaweed Cladophora rupestris collected in a Mediterranean area, in two sampling periods (January and April), was assayed. The chemical characterization of the lipidic fractions was performed by gas-chromatography and multinuclear and multidimensional NMR spectroscopy. In the lipidic extract of C. rupestris collected in January an antibacterial activity against Enterococcus sp., Streptococcus agalactiae and Vibrio cholerae non-O1 was recorded; by contrast, bacterial inhibition was measured on several Vibrio species only in April. The fatty acid profile of C. rupestris lipidic extract, analyzed by gas chromatography, resulted mainly composed of palmitic, myristic, oleic, α linolenic, palmitoleic and linoleic acids. Moreover, since α-linolenic acid was the predominant ω3 fatty acid in April, we suggest its involvement in the antibacterial activity observed in this month, taking also into account that pure α-linolenic acid resulted effective towards some vibrios strains. C. rupestris fatty acid profile revealed also an interesting composition in polyunsaturated fatty acids in both the considered periods with the ω6/ω3 ratio lower than 1, leading to conclude that this macroalga may be employed as a natural source of ω3. Finally, the (1)H NMR spectrum in CDCl3 of algal lipid fractions showed the characteristic signals of saturated (SAFAs) and unsaturated fatty acids (UFAs) as well as other metabolites and a marked difference in free fatty acids (FFAs) content for the two examined algal lipid fractions. It is noteworthy that C. rupestris lipidic extracts show, by NMR spectroscopy, the signal pattern of polyhydroxybutyrate, a natural biocompatible and biodegradable polymer. In conclusion, on account of its antimicrobial activity, nutritional value and bioplastic content, C. rupestris lipidic extract can be considered a promising source for future biotechnological applications.

Soybean meal enriched with microelements by biosorption--a new biological feed supplement for laying hens. Part I. Performance and egg traits

The aim of the study was to evaluate the effect of soybean meal enriched with Cu(II), Zn(II), Fe(II) and Cr(III) by biosorption on egg traits (egg weight, eggshell strength, eggshell thickness, yolk colour, albumen height) and performance of laying hens. Also, the effect of increased microelement doses in biological form on egg quality parameters and hens performance was investigated. A consumer questionnaire was undertaken to evaluate the organoleptic parameters of the eggs. Generally, our study showed that in the groups fed with the new biological supplement, egg quality parameters improved, including eggshell strength, eggshell thickness, albumen height and yolk colour. The biological form of microelements also improved the feed conversion rate, especially in the group fed with a biological form of Cr(III). Moreover, the new supplement improved organoleptic parameters of the eggs, in comparison to the inorganic form of microelements as well as to chelate. Enriched soybean meal could constitute an alternative for currently used feed additives with microelements.

Enrichment of soybean meal with microelements during the process of biosorption in a fixed-bed column

The aim of the present investigation was to enrich the mineral content of soybean meal with essential chromium and copper metal ions by a biosorption technique in a fixed-bed column. The values of column parameters were determined at various process conditions: pH, temperature, flow rate, and concentration of the feed solution; mass and size of the particles of the bed to determine the breakthrough curves. Biosorption efficiency at optimal conditions (pH 5.0, temperature = 20 °C, Cr(3+) concentration = 200 mg/L, flow rate = 10 mL/min, and sorbent mass = 40 g) was 71.4%. Maximum uptake for Cr(III) and Cu(II) obtained in column was around 15.3 and 12.3 mg/g, respectively. The model constants obtained in this study can be used for design pilot plant systems. Soybean enriched with microelements by biosorption can be considered as biological carrier of microelements and therefore used as the component of livestock feed.

The accumulation of metal (Co, Cr, Cu, Mn and Zn) in freshwater Ulva (Chlorophyta) and its habitat

The possibility of using freshwater Ulva (Chlorophyta) as a bioaccumulator of metals (Co, Cr, Cu, Mn and Zn) in lake and river water was examined weekly in the summer of 2010 in three types of samples: the water, the sediment and the thalli of Ulva. Samples of freshwater Ulva were collected from two aqueous ecosystems lie 250 km away from the basin of the Baltic Sea and 53 km from each other. A flow lake located in the centre of the big city was the first water reservoir (ten sites) and second, the suburban river (six sites). The mean metal concentrations in the Ulva tissue from the river and the lake decreased in the following order: Mn > Zn > Cr > Cu > Co and Mn > Cr > Zn > Cu > Co, respectively. Moreover, a negative and statistically significant correlation between Mn concentrations in the Ulva thalli and the river water was observed. Additionally, numerous correlations were noted between the different concentrations of metals within the Ulva thalli, in the water and in the sediment. The great concentrations of Mn and Zn and the smallest of Co were found in thalli of Ulva, irrespective of the type of the ecosystem from which samples of algal thalli originated. Freshwater Ulva populations examined in this study were clearly characterized a dozen or so times by the higher Mn and Cr accumulation than taxa from that genera coming from sea ecosystems. The calculated bioconcentration factor confirm the high potential for freshwater Ulva to be a bioaccumulator of trace metals in freshwater ecosystems.

Preparation and Evaluation ofAcetabularia-Modified Carbon Paste Electrode in Anodic Stripping Voltammetry of Copper and Lead Ions

Seaweed is well known about for potential in chelating heavy metals. In this study, carbon paste electrodes were fabricated with siphonous seaweedAcetabularia acetabulumas the modifiers to sense lead (II) and copper (II) by square-wave anodic stripping voltammetry. Various scan rates and deposition potentials were measured to obtain the optimal peak current for Pb(II) and Cu(II). Optimum conditions ofAcetabularia-CPE for sensing Pb(II) were at the scan rate of 75 mV/s and deposition potential of −800 mV, while for Cu(II) sensing were at 100 mV/s and −300 mV, respectively. The electrodes were characterized by the duration of accumulation time, preconcentration over a range of standards, supporting electrolyte, and standard solutions of various pH values. Interference studies were carried out. Both Zn(II) and Cu(II) were found to interfere with Pb(II) sensing, whereas only Zn(II) causes interference with Cu(II) sensing. The electrode was found to have good regeneration ability via electrochemical cleaning. Preliminary testing of complex samples such as NPK fertilisers, black soil, and sea salt samples was included.

Freshwater Ulva (Chlorophyta) as a bioaccumulator of selected heavy metals (Cd, Ni and Pb) and alkaline earth metals (Ca and Mg)

We analyzed the ability of freshwater taxa of the genus Ulva (Ulvaceae, Chlorophyta) to serve as bioindicators of metal in lakes and rivers. Changes in heavy metal (Ni, Cd and Pb) and alkaline earth metal (Ca and Mg) concentrations in freshwater Ulva thalli were investigated during the period from June to August 2010. The study was conducted in two ecosystems in Western Poland, the Malta lake (10 sites) and the Nielba river (six sites). Three components were collected for each sample, including water, sediment and Ulva thalli. The average concentrations of metals in the water sample and in the macroalgae decreased in the following order: Ca>Mg>Ni>Pb>Cd. The sediment revealed a slightly altered order: Ca>Mg>Pb>Ni>Cd. Ca and Mg were found at the highest concentrations in thalli due to the presence of carbonate on its surface. Among the examined heavy metals in thalli, Ni was in the highest concentration, and Cd found in the lowest concentration. There were statistically significant correlations between the levels of metals in macroalgae, water and sediment. Freshwater populations of Ulva exhibited a greater efficiency to bioaccumulate nickel as compared to species derived from marine ecosystems.

Depressive effects on the central nervous system and underlying mechanism of the enzymatic extract and its phlorotannin-rich fraction from Ecklonia cava edible brown seaweed

Marine plants have been reported to possess various pharmacological properties; however, there have been few reports on their neuropharmacological effects. Terrestrial plants have depressive effects on the central nervous system (CNS) because of their polyphenols which make them effective as anticonvulsants and sleep inducers. We investigated in this study the depressive effects of the polyphenol-rich brown seaweed, Ecklonia cava (EC), on CNS. An EC enzymatic extract (ECEE) showed significant anticonvulsive (>500 mg/kg) and sleep-inducing (>500 mg/kg) effects on the respective mice seizure induced by picrotoxin and on the mice sleep induced by pentobarbital. The phlorotannin-rich fraction (PTRF) from ECEE significantly potentiated the pentobarbital-induced sleep at >50 mg/kg. PTRF had binding activity to the gamma aminobutyric acid type A (GABA(A))-benzodiazepine (BZD) receptors. The sleep-inducing effects of diazepam (DZP, a well-known GABA(A)-BZD agonist), ECEE, and PTRF were completely blocked by flumazenil, a well-known antagonist of GABA(A)-BZD receptors. These results imply that ECEE produced depressive effects on CNS by positive allosteric modulation of its phlorotannins on GABA(A)-BZD receptors like DZP. Our study proposes EC as a candidate for the effective treatment of neuropsychiatric disorders such as anxiety and insomnia.