Enteromorpha Intestinalis Research Articles

Chemical Characterization of Selected Algae and Cyanobacteria from Bulgaria as Sources of Compounds with Antioxidant Activity

The current research focused on algae from the waters of the Black Sea—Chaetomorpha linum, Ulva intestinalis, Ericaria crinita, and bioreactors—Chlorella spp. and Arthrospira platensis/cyanobacterium/. Pigment content, total phenolic content, and antioxidant capacity were investigated for their use as pharmaceutical, food, and cosmetic ingredients. E. crinita exhibited the highest antioxidant activity by ORAC and HORAC (463.3 µmol TE/g and 463.3 µmol GAE/g) and the highest total content of polyphenols and rutin of the investigated algae. Lower protein content was found in saltwater algae than in freshwater algae. For the first time, biologically active substances from the Bulgarian A. platensis and Chlorella spp., produced in a bioreactor, have been quantitatively identified. A. platensis contained rutin (141.25 mg/100 g), naringenin (42.17 mg/100 g), quercetin (26.74 mg/100 g), kaempferol, and quercetin-3-β-glycoside. Phenolic acids were isolated: neochlorogenic (172.27 mg/100 g) for lyophilized and 5783 mg/100 g for convection-dried A. platensis. It has been found that the protein content in A. platensis (convection dried) and Chlorella spp. (lyophilized) was nearly 54% higher than that of green algae U. intestinalis from Varna. The lyophilization process reduced the protein content of A. platensis samples by almost 20%. The high protein content of convection-dried A. platensis (43.4%) and lyophilized Chlorella spp. (43.7%) identified them as suitable emulsifiers in colloidal and emulsion systems.

Omega-3 fatty acid and B12 vitamin content in Baltic algae

Seaweeds have been gaining popularity in the Western world due to increased interest in alternative food sources and improving the nutritional profile and functionality of food products. This paper analyzed the omega-3 fatty acids such as eicosapentaenoic acid (EPA) and α-linoleic acid (ALA) and B12 vitamin content in the most common Baltic seaweeds. These nutrients have an important part in the human diet. Five seaweeds species (Fucus vesiculosus, Furcellaria lumbricalis, Cladophora glomerata, Pilayella littoralis and Ulva intestinalis) were sampled during April–May, June–July, and August–September. The fatty acids were determined by GC–MS whereas B12 content was analyzed by HPLC-UV. 16S rRNA amplification from community DNA and sequencing was carried out to evaluate B12 synthesizing microorganisms associated with the studied seaweeds. The results showed that F. vesiculosus (5.19 ± 0.32 mg/gDW) was the best source of EPA, followed by F. lumbricalis, C. glomerata, P. littoralis and U. intestinalis irresponsibly of sampling time. The ALA content had little variability between species (1.07–2.45 mg/ g DW). The B12 concentration varied across seasons, being generally lowest during the June–July period. The highest concentration of B12 across all three seasons was in C. glomerata samples (53.55 ± 9.69 μg/100gDW). The lowest B12 vitamin concentration was in F. vesiculosus (4.14 ± 0.36 μg/100gDW). 16S RNA amplicon analysis revealed a correlation between Cyanobacteria and EPA, while no correlation could be found between B12 neither on phyla nor family levels. B12 content in the samples was in correlation with 5 potentially B12 synthesizing bacteria species (Rhodobacter capsulatus, Rhodobacter sphaeroides, Pseudomonas putida, Xanthomonas oligotrophicus and Aeromonas hydrophila) although the abundance of corresponding OTUs did not exceed 1 %.

Biological indicators as tools for monitoring water quality of a hot spot area on the Egyptian Mediterranean Coast

El-Mex Bay is a semi-sheltered coastal embayment located west of Alexandria, the Egyptian Mediterranean Sea. It is considered as a hot spot area receiving industrial, agricultural, and domestic wastes from the adjacent Lake Mariut through El-Umum Drain. To evaluate the water quality of the bay, phytoplankton and macroalgae as biological tools were investigated seasonally concerning physicochemical parameters from 2018 to 2019. The results indicated that the Bay harbored a diversified phytoplankton community (162 species), comprising 99 freshwater forms, 38 marine, 22 euryhaline, and only 3 brackish forms. The total average phytoplankton abundance was 419,414 unit/L. Few species were responsible for the main bulk of phytoplankton namely Merismopedia tenuissima, Cylindrotheca closterium, Cyclotella sp., Skeletonema costatum, Scenedesmus quadricauda, Scenedesmus bijugus, and Tetradesmus dimorphus. During the study period, El-Mex Bay was affected by the presence of 13 harmful and /or toxic algal species, among which the mediophyte species Skeletonema costatum was responsible for the peak occurring during autumn (2018). The results of the recorded nutrients indicated that the Bay is highly loaded, where NH4, NO2, NO3, PO4, and SiO4 attained 141.68 µM, 25.61 µM, 151.16 µM, 10.73 µM, and 232.86 µM, respectively. The macroalgal flora was represented only by the two opportunistic species (Ulva fasciata and Ulva intestinalis). Both species could survive in freshwater conditions exhibiting very broad salinity tolerance (6.51–38.41‰) and a high level of nitrogenous compounds. Those results revealed that El-Mex Bay suffers from pollution and deterioration of water quality.

Variability at multiple spatial scales in intertidal and subtidal macrobenthic communities in a fjord with glaciers, Magellanic Subantarctic ecoregion, Chile

It has been observed in high-latitude marine environments of the Southern Hemisphere that the variability in the ecological patterns of macrobenthic communities show variations at different spatial scales (i.e. cm to km), mainly influenced by environmental stress gradients. We examined macrobenthic communities of intertidal and subtidal habitats in a glacial fjord using taxonomic, ecological and oceanographic approaches, estimating vertical and horizontal variation using a nested design with different spatial scales ranging from centimeters to kilometers (quadrats, patches, shore and sites respectively). We found that vertical patterns in taxon richness and community structure were significant in both habitats. These patterns also showed horizontal variability at different spatial scales, becoming more pronounced at smaller scales (quadrats). The dominant taxa in the intertidal (macroalga) and subtidal (macroinvertebrate) communities also exhibited a scale-dependent distribution pattern, indicating that the greatest horizontal variation occurs at small spatial scales. Annual and opportunistic green algae such as Ulva intestinalis and Cladophora flexuosa were dominant in the intertidal, while the dominant taxa in the subtidal were the filter-feeding bivalve Aulacomya atra and the suspensivorous hydrozoan Symplectoscyphus marionensis. The results were related to biological interactions and local abiotic factors characteristic of an estuarine system influenced by glaciers, with lower salinity and temperature and higher turbidity in sites close to glaciers. The information generated on diversity patterns is very relevant and can serve as a baseline in the evaluation of ecological patterns of shallow macrobenthic communities in environmental gradients influenced by glaciers in the Magellanic Subantarctic ecoregion.

Effect of solid-state fermentation and ultrasonication processes on antimicrobial and antioxidant properties of algae extracts.

Algal biomass (AB) is prospective source of valuable compounds, however, Baltic Sea macroalgae have some challenges, because of their high microbial and chemical contamination. These problems can be solved, by using appropriate technologies for AG pre-treatment. The aim of this study was to evaluate the influence of two pre-treatments, solid-state fermentation with the Lactiplantibacillus plantarum LUHS135 and ultrasonication, on the antioxidant and antimicrobial characteristics of macro- (Cladophora rupestris, Cladophora glomerata, Furcellaria lumbricalis, Ulva intestinalis) and Spirulina (Arthrospira platensis) extracts. Also, combinations of extracts and LUHS135 were developed and their characteristics were evaluated. The total phenolic compound content was determined from the calibration curve and expressed in mg of gallic acid equivalents; antioxidant activity was measured by a Trolox equivalent antioxidant capacity assay using the DPPH• (1,1-diphenyl-2-picrylhydrazyl), ABTS•+ 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid), FRAP (Ferric Reducing Ability of Plasma) discoloration methods. Antimicrobial activity was measured by using agar well diffusion assay and in a liquid medium. The highest DPPH• and ABTS•+ was shown by C.rupestris and F.lumbricalis extract × LUHS135 combinations, the highest FRAP - by non-pretreated C.rupestris and F.lumbricalis extract × LUHS135 combinations. Ultrasonicated samples inhibited four out of seven tested pathogens. Finally, the tested pre-treatments showed good perspectives and can be recommended for AB valorization.

Moringa leaf extract and green algae improve the growth and physiological attributes of Mentha species under salt stress

Climate change, food scarcity, salt stress, and a rapidly growing population are just a few of the major global challenges. The current study examined into whether Moringa oleifera (L.) leaf extract and green algae (Ulva intestinalis) could help improve salt tolerance in Mentha species (Mentha piperita; Mentha longifolia). Moringa leaf extract (MLE) and green algae (GA) were applied to Mentha seedlings under three different salt treatments: 0 mM, 20 mM, 40 mM, 60 mM, and 90 mM, respectively. For each treatment, three biological replicates were conducted, with each replicate containing at least three plants. Mentha species were negatively affected by salt stress in terms of shoot length, fresh and dry weight, photosynthetic pigments, and antioxidant enzyme activities. However, the use of MLE and GA significantly improved the development and physiology of Mentha species under salt stress conditions. The MLE and GA treatments dramatically (p ≤ 0.001) increased SOD activity by 7% and 10%, CAT activity by 16% and 30%, APX activity by 34% and 56%, GPX activity by 12% and 47%, respectively, in Mentha piperita seedlings, which in turn strikingly increased superoxide dismutase (SOD) activity by 6% and 9%, catalase (CAT) activity by 15%, 28% and 44%, 27%, ascorbate peroxidase (APX) activity by 39% and 60%, glutathione peroxidase (GPX) activity by 23% and 58%, respectively, in Mentha longifolia seedlings, relative to the control. Aiming to answer questions about the relationship between plant extraction and traditional agricultural methods, this research greatly advances the goal of sustainable development for improving plant productivity by providing a much safer and more environmentally friendly adaptability.

The production of dissolved organic carbon by macroalgae and its consumption by marine bacteria: Implications for coastal ecosystems

Through the fixation of large quantities of dissolved inorganic carbon (DIC), macroalgae facilitate the energetic foundation of highly productive coastal ecosystems. While the processes controlling photosynthesis and carbon fixation by macroalgae are well known, the fate of organic matter fixed by macroalgae is less well understood. This study quantified release rates of DOC by three ecologically significant Baltic macroalgae species: the perennial habitat forming Fucus vesiculosus and Furcellaria lumbricalis, and the seasonal fast-growing Ulva intestinalis, under both light and dark conditions. The released products were assessed using bacterial incubations whereby radiolabeled leucine was used to evaluate the uptake and lability of these products by marine heterotrophic bacteria. DOC was found to be released by both F. vesiculosus and U. intestinalis at rates of 0.27 mg C·h−1 under light and 0.13 mg C·h−1 per unit of dry mass under dark treatments, respectively, whereas F. lumbricalis DOC release was observed to be negligible under both light and dark. Our findings further validate previous hypotheses that factors such as photosynthetic activity are a primary driver behind DOC release and that DOC release is not an entirely passive process. Additionally, we reaffirm the need to relate a given species life characteristics and habitat in order to understand why DOC products are released. The consumption of macroalgae-derived DOC by heterotrophic bacteria reveals that released DOC is variable in its lability. After a period of 12 h and under maximum photosynthetic conditions, the release of DOC by F. vesiculosus and U. intestinalis achieved a peak rate of 219 µg C·L−1·day−1 and 214 µg C·L−1·day−1 for each gram of dry weight material, respectively, directly into the microbial loop via heterotrophic bacterial consumption. In contrast, F. lumbricalis’ low rate of DOC release and the subsequent low bacterial consumption indicate that habitats dominated by this species have a reduced importance in the transfer energy via the microbial loop. These findings have implications for how we view carbon transfer within coastal food webs and highlight how changes in species composition and coverage may dramatically affect coastal ecosystem productivity through the microbial loop.

The effect of Enteromorpha intestinalis and Corallina elongata on physiological parameters of Zea mays L.

Purpose: Algae are living organisms capable of photosynthesis and live mainly in an aquatic environment (marine or freshwater), and considered as plants like those growing on the soil. It can therefore be used to enrich the soil in organic matter, and mineral elements, as for composting green waste, for example. The objective of this study was to investigate the effect of marine macroalgae Enteromorpha intestinalis (Ulvophycae) and Corallina elongata (Corallinacae) as biofertilizers on the growth of Zea mays L. Method: After rinsing, the algae were ground into a fine powder. The powder obtained from each seaweed was divided into two batches. For the first batch, the seaweed powder (AP), was used directly in the pots one week before planting. Two concentrations, 5% and 10%, were studied. The second batch was used to prepare liquid algal fertilizer (ALF). To determine the mineral composition of each seaweed, X-ray fluorescence analysis was performed. the biofertilizing potential of Enteromorpha intestinalis and Corallina elongata was studied on corn plants, evaluating the effect of these two algae at different growth stages (15, 25, 45 and 60 days) and the chlorophyll a and b content. Results: The elemental analysis of the two algae by X-ray Fluorescence shows that the main elements are water, chlorine, potassium, calcium, silicon, natrium, magnesium, iron and sulfur. The results show that E.intestinalis is richer in minerals compared to C.elongata, except for Strontium and calcium, where C.elongata is more rich. Conclusion: The results of this study showed that the macroalgae Enteromorpha intestinalis and Corallina elongata from the Atlantic coast of Morocco are valuable biofertilizers. On the other hand, the application of seaweed extract is more effective than the application of seaweed powder, and Enteromorpha intestinalis can affect the growth parameters at a low concentration (5%), unlike Corallina elongata. The different positive roles of algae in agriculture should be clarified, as our results showed that they can be used as an excellent fertilizer.

Heavy metals and metalloids in edible seaweeds of Saint Martin's Island, Bay of Bengal, and their potential health risks

The present study aimed to assess the levels of heavy metals and metalloids present in six seaweeds and their potential impact on consumption. The highest concentration of 11 metals, i.e., Be (0.47 mg/kg), Co (4.34 mg/kg), Cr (23.46 mg/kg), Cu (11.96 mg/kg), Fe (2290.26 mg/kg), Li (11.55 mg/kg), Ni (13.75 mg/kg), Pb (6.67 mg/kg), Ti (736.62 mg/kg), Tl (0.14 mg/kg), and V (33.09 mg/kg) were observed in Enteromorpha intestinalis (green seaweeds). Besides, the highest concentration of Ca (1071.09 mg/kg), Cd (5.81 mg/kg), Mn (1003.41 mg/kg), Sr (2838.86 mg/kg), and Zn (41.95 mg/kg) were found in Padina tetrastromatica (brown seaweeds). Eight metals (Pb, Cd, Zn, Cu, Ni, Mn, Cr, Fe) have been used to assess the potential health risk for adults, but no potential health risk was detected (HQ value > 1). The HI value of E. intestinalis and P. tetrastromatica were >1, implying that these two seaweeds are not safe for human consumption as there is a carcinogenic health risk for adults.

Microhabitat Preference of Strombidae in Selected Intertidal Areas of Zamboanga del Norte and Misamis Occidental, Philippines

This study aimed to identify the microhabitat preference of Strombidae species present in selected intertidal zones of Zamboanga del Norte and Misamis Occidental. A total of 406 individuals of Strombidae were collected and identified into 15 species. Most species of Strombidae were recorded to be abundant in seagrasses (Cymodocea rotundata and Thalassia hemprichii) and in algae (Gracilaria salicornia, Ulva lactuca and Ulva intestinalis). Strombidae were also observed along rocks, muddy sand, black sand, sediments and tide pools. A Kruskal-Wallis Test showed that there was a significant difference in species abundance among different microhabitat types (H[6] = 13.46, p = 0.036). This implies that the abundance of species among different habitats was not the same. Supporting this, the Cramer’s contingency test revealed a significant association between the abundance of species to their microhabitat type with a contingency coefficient of 0.76. Canarium labiatum was observed to inhabit G. salicornia, while Canarium mutabile preferred both rocks and tide pools. Canarium urceus favored C. rotundata; Canarium (Canarium) esculentum occurred in G. salicornia and T. hemprichii. Conomurex luhuanus was observed in U. intestinalis and G. salicornia. Euprotomus aurisdianae inhabited the seagrass, while Euprotomus bulla occurred in T. hemprichii and muddy sand. Laevistrombus (Gonggonus) turturella inhabited the C. rotundata. Lastly, Lentigo lentiginosus and all Lambis species were noticed in G. salicornia. Strombidae preferred both seagrasses and algae apparently because these microhabitat types serve as food and nutrient sources to these species.

Differential responses of bloom-forming Ulva intestinalis and economically important Gracilariopsis lemaneiformis to marine heatwaves under changing nitrate conditions

Marine heatwaves (MHWs) are affecting the survival of macroalgae. However, little is known regarding how the impacts of MHWs are regulated by nitrogen availability. In this study, we investigated the physiological and genetic responses of a green-tide macroalga Ulva intestinalis Linnaeus and a commercially cultivated macroalga Gracilariopsis lemaneiformis (Bory) E.Y. Dawson, Acleto & Foldvik under different nitrate conditions to simulated MHWs. Under nitrogen limited conditions (LN), heatwaves did not significantly affect biomass or Fv/Fm of U. intestinalis although it led to an earlier biomass decline due to more reproduction events, and meanwhile an upregulation in genes related to TCA cycle and oxidative phosphorylation was detected, supporting sporulation. Under nitrogen replete conditions (HN), heatwaves did not change biomass, Fv/Fm or photosynthetic pigments but reduced reproduction rate along with insignificant change of oxidative phosphorylation and TCA cycle related genes. Meanwhile, genes related to photosynthesis and glutathione metabolism were upregulated. Regarding G. lemaneiformis, heatwaves reduced its Fv/Fm and photosynthetic pigments content, leading to bleaching and death, and photosynthesis-related genes were also downregulated at LN. Fv/Fm was improved and photosynthesis-related genes were up-regulated by the combination of nitrogen enrichment and heatwaves, whereas G. lemaneiformis remained bleached and died by day 12. Therefore, U. intestinalis could survive heatwaves through shifting to micropropagules at LN and protecting its photosynthesis at HN. In contrast, G. lemaneiformis died of bleaching when suffering heatwaves regardless of nitrogen availability. These findings suggest that in future oceans with eutrophication and MHWs, the harmful alga U. intestinalis may have more advantages over the economic alga G. lemaneiformis.

Green algae as bioindicators for long-term nutrient pollution along a coastal eutrophication gradient

Eutrophication is a strong driver that modifies coastal areas globally and measures to reduce nutrient input are implemented in many areas. As nutrient concentrations in coastal waters can vary drastically with time and space, quantifying the impacts of the actions taken to reduce eutrophication can be logistically challenging. In this study, we assessed the variation in nutrient concentrations along a coastal eutrophication gradient in the Northern Baltic Sea and estimated whether ephemeral macroalgae can function as bioindicators to reflect long-term water nutrient concentrations. We studied spatial variation in total phosphorus (P) and nitrogen (N) concentrations in two green algal species, Cladophora glomerata and Ulva intestinalis, and temporal variation in nutrient concentrations in C. glomerata. Nutrient concentrations in water and algae showed seasonal and between-year variation along the gradient. Phosphorus and nitrogen concentrations in C. glomerata reflected the preceding (0–4 months) nutrient concentrations in water, while nutrient concentrations in U. intestinalis were less reliable indicators of the current and preceding water nutrient concentrations. While more data is needed to evaluate between-year variation, the results indicate that C. glomerata is a useful tool to assess both the spatial and temporal variation in nutrient run-off from land, especially to complement sparse water nutrient analyses.

Assessing the potential for sea-based macroalgae cultivation and its application for nutrient removal in the Baltic Sea

Marine eutrophication is a pervasive and growing threat to global sustainability. Macroalgal cultivation is a promising circular economy solution to achieve nutrient reduction and food security. However, the location of production hotspots is not well known. In this paper the production potential of macroalgae of high commercial value was predicted across the Baltic Sea region. In addition, the nutrient limitation within and adjacent to macroalgal farms was investigated to suggest optimal site-specific configuration of farms. The production potential of Saccharina latissima was largely driven by salinity and the highest production yields are expected in the westernmost Baltic Sea areas where salinity is >23. The direct and interactive effects of light availability, temperature, salinity and nutrient concentrations regulated the predicted changes in the production of Ulva intestinalis and Fucus vesiculosus. The western and southern Baltic Sea exhibited the highest farming potential for these species, with promising areas also in the eastern Baltic Sea. Macroalgal farming did not induce significant nutrient limitation. The expected spatial propagation of nutrient limitation caused by macroalgal farming was less than 100–250 m. Higher propagation distances were found in areas of low nutrient and low water exchange (e.g. offshore areas in the Baltic Proper) and smaller distances in areas of high nutrient and high water exchange (e.g. western Baltic Sea and Gulf of Riga). The generated maps provide the most sought-after input to support blue growth initiatives that foster the sustainable development of macroalgal cultivation and reduction of in situ nutrient loads in the Baltic Sea.

Achromobacter xylosoxidans and Enteromorpha intestinalis Extract Improve Tomato Growth under Salt Stress

The effect of seed coating salt-stressed tomato with the bacterium Achromobacter xylosoxidans BOA4 and/or irrigation with an extract of the marine algae Enteromorpha intestinalis (EI) is herein evaluated. The plant shoots and roots were harvested separately on day 50, following extensive saline stress. The addition of BOA4 and/or EI extract resulted in an average increase of 33% in plant shoot DW, but an averaged decrease of 44% in the root to shoot biomass ratio. Anthocyanin content increased by over 34% and 44% with EI and BOA4 plus EI treatments, respectively. Since enhanced protein tyrosine nitration (PTN) is a known plant response to salt stress, the PTN level was inspected through 3-nitrotyrosine content determination. This was drastically increased by salt stress; however, BOA4, EI or both caused an averaged PTN decrease of 30% in stressed roots or shoots. This PTN response could be associated with tomato phenotypic characteristics and is postulated to be inversely correlated to cytokinin contents in stressed plants, namely cis-zeatin-type-cis-zeatin (cZ) plus cis-zeatin riboside (cZR), and isopentenyladenine (iP). The latter showed a drastic average increase by 3.6-fold following BOA4 and/or EI treatments of salinized tomato. This increment could be related to cytokinin biosynthesis induced by the applied bio-stimulants; IP and derivatives are the main cytokinins in seaweeds, and Achromobacter xylosoxidans BOA4 was shown to produce up to 17.5 pmol mL−1 of isopentenyladenine. This work is the first report on the influence of bio-stimulants, used to improve salt stress tolerance, on plant PTN levels; BOA4 and/or EI treatments decreased PTN, while increasing cis-zeatin-type and iP cytokinins in tomato, the latter showed an enhanced tolerance to salt stress.

Allelopathic effect of Ulva intestinalis thallus on selected Baltic cyanobacteria

Macroalgae have been found to produce active allelochemicals that inhibit of growth other organisms that compete with them for light and space. However, their allelopathic activity on Baltic cyanobacteria is still insufficiently recognised. Therefore, this study aimed to demonstrate the allelopathic effects of Baltic macroalga thallus (Ulva intestinalis) on the growth and photosynthetic activity of three bloom-forming cyanobacteria: Aphanizomenon sp., Nodularia spumigena, and Nostoc sp. This study investigated the cell count of the analysed cyanobacteria (N 105 mL-1), the maximum quantum yield of the second photosystem (PSII) in the dark (Fv/Fm), and the real quantum yield of PSII in the light (ΦPSII) (in the control and the experiments). After 7 days of exposure, the following were added: 0.01, 0.05, and 0.1 g mL-1 of U. intestinalis fresh thallus. It was found that thallus obtained from U. intestinalis had no statistically significant effect on the number of cells of the cyanobacterium Aphanizomenon sp. (at 0.05 and 0.1 g mL-1) and Nostoc sp. (at concentrations of 0.01 and 0.05 g mL−1). On the other hand, it was examined a stimulating effect of 0.01 g mL-1 of the fresh thallus on the number of Aphanizomenon sp. cells which constituted 168%, relative to the control. It was shown that the fresh thallus addition resulted in a decrease in the number of N. spumigena cells (45%, 27%, and 46% after addition of 0.01, 0.05, and 0.1 g wet weight mL−1 of fresh thallus, respectively). In experiments with Nostoc sp., the addition of U. intestinalis thallus has been a negative effect on cyanobacterial growth at 0.1 g mL−1 and constituted 97% of control. It was also found, that U. intestinalis had no allelopathic effect on fluorescence parameters of N. spumigena. All tested concentrations of thallus U. intestinalis (0.01, 0.05, and 0.1 g wet weight mL-1) stimulated the values of Fv/Fm or ΦPSII of cyanobacteria Aphanizomenon sp. and Nostoc sp. compared to the control. These studies help define the role of U. intestinalis allelopathy as a biological factor in the distribution of bloom-forming cyanobacteria in the coastal Baltic Sea region.

Мікроскопічні водорості водойм Кінбурнської піщаної коси (НПП «Білобережжя Святослава», Україна)

Taxonomical composition of microscopic algae of different reservoirs (Dnieper estuary, Kefalny, Guryansky and Cherepashy lakes, Yagorlytsky Bay) of the Kinburn sand spit of north-western part of the Black Sea (National Nature Park “Biloberezhzha of Svyatoslav”) is studied. Material tests that is collected on sandy and silty soils served as for researches, and also in becoming overgrown with of mussels Mytilus galloprovincialis Lamarck, Mya arenaria L., Cerastoderma lamarcki Reeve and Balanus improvisus Darwin, macroscopic algae (Ceramium virgatum Roth, Cladophora vagabunda (L.) Hoek, C. siwaschensis C.Meyer, Ulva intestinalis L., Polysiphonia elongata (Huds.) Harv.) of Kіnburnska braid from September in 2019 for October in 2021. On the whole it was collected and analysed 90 standards. 116 species of microscopic algae are educed, that to 74 genera, 52 families, 31 orders, 9 classes, 6 divisions, belong, 3 kingdoms and 2 empires. After systematic composition Bacillariophyta (76 species) prevailed above Cyanophyta (26), Chlorophyta (7), Dinophyta (3), Chrysophyta (3) and by Haptophyta (1). 86 species of algae were found in the microphytobenthos of Yagorlyk Bay, 56 in Dnieper estuary, 33 in Cherepashy, 22 in Guryansky and 17 in Kefalny lakes. As a result of researches it was educed 2 new and 4 rare species of microscopic algae for the aquatorium of the Black Sea.

Vegetation of the supralittoral and upper sublittoral zones of the Western German Baltic Sea coast: a phytosociological study

Abstract Supralittoral and shallow water seaweed communities are particularly exposed to impacts such as climate change and disturbance by humans. Therefore, their classification, the study of composition, and the monitoring of their structural changes are particularly important. A phytosociological survey of the supralittoral and upper sublittoral vegetation of the South West Baltic Sea revealed eight phytobenthos communities with two variants comprising 35 taxa of macrophytes (18 taxa of Chlorophyta, 13 taxa of Rhodophyta and four taxa of Phaeophyceae, Ochrophyta). Five of the eight communities were dominated by Ulvales (Ulva intestinalis, Kornmannia leptoderma, and three Blidingia species), the other three by Fucus vesiculosus. Most Fucus vesiculosus-dominated communities contained U. intestinalis and U. linza as subdominants. Only one of the communities had until now been described as an association ( Ulvetum intestinalis Feldman 1937). The syntaxonomic composition of the investigated vegetation includes both phytocenoses with the domination of green algae ( Ulvetum intestinalis Feldman 1937 and communities of Blidingia marginata, unidentified Blidingia spp. and Kornmannia leptoderma), as well as a number of communities dominated by Fucus vesiculosus. Mainly boreal Atlantic species and cosmopolitans make up the bulk of the species in these associations.

Feasibility of United Arab Emirates Native Seaweed Ulva intestinalis as a Food Source: Study of Nutritional and Mineral Compositions

Food resources are limited in arid countries such as the United Arab Emirates (UAE); the salinity of the groundwater, together with a lack of natural fresh water sources and arable land, force the country to import most of its food. However, seaweed could play an important role in providing a locally available food resource, as it does not require fresh water and arable land to grow. The traditional use of several seaweed species as food sources has been documented in Asia and the Americas, where their nutritional composition has been well reported. Although the UAE’s aquatic environment is quite harsh due to high water salinity (over 40 g/L) and high surface water temperatures (over 35 °C), its native seaweed species could play a role as a food source in this arid region, thereby bolstering the country’s level of food security. To evaluate its potential in this context, fresh samples of the native Ulva intestinalis seaweed were collected in the shallow waters of Abu Dhabi Emirate, UAE. These samples were calculated to contain 34.38 ± 0.24 kcal, with a biomass composition of 5.185 ± 0.04% carbohydrate, 3.32 ± 0.14% protein, and 0.04 ± 0.01% fat (by dry matter). Of all the minerals present in the biomass, potassium had the highest concentration (7947 ± 319.5 ppm), followed by magnesium (3075.9 ± 1357 ppm) and sodium (756.3 ± 478 ppm). The water-soluble vitamins B1, B2, B3, B6, and C were below the detection limit in the samples. The rich concentration of essential minerals such as potassium, magnesium, iron and zinc in Ulva intestinalis makes it a promising novel food source. To the best of our knowledge, this is the first experimental study to examine the feasibility of using seaweed that is native to the UAE as a nutritional and sustainable food source in order to address the challenge of food security currently being faced by the country.

Cultivation of seaweeds in food production process waters: Evaluation of growth and crude protein content

There is an increasing demand for sustainably produced, protein-rich, and nutritious food. Seaweeds are promising protein sources for the future if their protein content can be optimized, something which can be achieved by cultivation in elevated nutrient concentrations. Cultivation of seaweeds in integration with fish farms have received much attention lately, but using nutrient-rich process waters from other food industries as feed stock for seaweed has rarely been studied. Here, we demonstrate a simple and sustainable strategy to answer the increasing world demand for food rich in plant-based proteins by connecting food production process waters with seaweed cultivation. We compared growth rates and crude protein content of four different seaweed species, the brown species Saccharina latissima, and the green species Ulva fenestrata, Ulva intestinalis, and Chaetomorpha linum, when cultivated in two dilutions (providing 20 and 200 μM ammonium) of eight different process waters emerging from recirculating salmon aquaculture systems as well as from herring, shrimp and oat processing. Growth rates of the green seaweeds were up to 64% higher, and crude protein content was almost up to four times higher when cultivated in the food production process waters, compared to seawater controls. Growth rates were generally higher in presence of 20 μM compared to 200 μM ammonium, while crude protein content was either unaffected or positively affected by the increasing ammonium concentration. This study indicates the potential for cultivating seaweeds with food production process waters to generate additional protein-rich biomass while nutrients are being circulated back to the food chain. A new nutrient loop is thus illustrated, in which the costly disposal of food production process waters is instead turned into value by seaweed cultivation.

Effect of Polysaccharides From Enteromorpha intestinalis on Intestinal Function in Sprague Dawley Rats.

This study aims to determine the effect of polysaccharides extracted from Enteromorpha intestinalis (EI) on the intestinal function of Sprague Dawley (SD) rats. The polysaccharides were extracted from the green alga using water and alkaline solution, where these extracts were named WPEI and APEI, respectively. The dried powder of EI was labeled as DPEI. Proximate compositions, minerals, and amino acids of the DPEI, WPEI, and APEI were determined. The growth-promoting effect of the polysaccharides on selected intestinal microflora was determined based on the plate count method. In contrast, the in vivo effect of DPEI and its polysaccharides on the intestinal function of the SD rats was determined. These rats were fed with 1% WPEI, APEI, and DPEI. The result showed that APEI had lower total sugars and total proteins content than the WPEI. WPEI did not contain arabinose. The WPEI and APEI also had a better ability to promote microbial growth than the DPEI. The in vivo study showed that WPEI improved intestinal peristalsis and other intestinal functions compared with the other rat groups. The average final body weight of the experimental rats treated with DPEI was also lower than the other groups. The pH value of the feces of all treated rats was lower than the control rats, and the moisture content of the fecal samples of these experimental groups was higher than the control group. Also, the intestinal activated carbon propulsion of the WPEI, APEI, and DPEI fed rats increased. Among the short-chain fatty acids content determined in the fecal samples, the propionic acid content of the WPEI group was significantly highest. Therefore, WPEI had the best effect in improving intestinal digestion.