Differential acclimation responses to irradiance and temperature in two co-occurring seaweed species in Arctic fjords

Arctic fjord systems experience large amplitudes of change in temperature and radiation regime due to climate warming and the related decrease in sea ice. The resultant increase in irradiance entering the water column influences photosynthetic activity of benthic and pelagic primary producers. The subtidal brown alga Desmarestia aculeata and the intertidal red alga Palmaria palmata populate the cold-temperate coasts of the North Atlantic, reaching the polar zone. To evaluate their acclimation potential, we collected both species in Kongsfjorden, Svalbard (78.9°N, 11.9°E), during the Arctic summer and exposed specimens to two different PAR levels (50 and 500 μmol photons m−2 s−1) and temperatures (0, 4 and 8 °C) for 21 days. Photosynthetic parameters and biochemical features (pigment concentration and antioxidants) were assessed. In general, high irradiance was the factor that generated a negative effect for D. aculeata and P. palmata in the photosynthetic parameters of the photosynthesis–irradiance curve and Fv/Fm. The pigment concentration in both species tended to decrease with increasing irradiance. Antioxidant level showed different trends for both species: in D. aculeata, antioxidant potential increased with high irradiance and temperature, while in P. palmata, it only increased with high irradiance. Both species showed responses to the interaction of irradiance and temperature, although D. aculeata was more sensitive to high irradiance than P. palmata. Our study shows how these species, which have similar geographical distribution in the North Atlantic and the Arctic but belong to different taxonomic lineages, have similar strategies of acclimation, although they respond differently to ecophysiological parameters.

Exploring the Potential of Icelandic Seaweeds Extracts Produced by Aqueous Pulsed Electric Fields-Assisted Extraction for Cosmetic Applications

A growing concern for overall health is driving a global market of natural ingredients not only in the food industry but also in the cosmetic field. In this study, a screening on potential cosmetic applications of aqueous extracts from three Icelandic seaweeds produced by pulsed electric fields (PEF) was performed. Produced extracts by PEF from Ulva lactuca, Alaria esculenta and Palmaria palmata were compared with the traditional hot water extraction in terms of polyphenol, flavonoid and carbohydrate content. Moreover, antioxidant properties and enzymatic inhibitory activities were evaluated by using in vitro assays. PEF exhibited similar results to the traditional method, showing several advantages such as its non-thermal nature and shorter extraction time. Amongst the three Icelandic species, Alaria esculenta showed the highest content of phenolic (mean value 8869.7 µg GAE/g dw) and flavonoid (mean value 12,098.7 µg QE/g dw) compounds, also exhibiting the highest antioxidant capacities. Moreover, Alaria esculenta extracts exhibited excellent anti-enzymatic activities (76.9, 72.8, 93.0 and 100% for collagenase, elastase, tyrosinase and hyaluronidase, respectively) for their use in skin whitening and anti-aging products. Thus, our preliminary study suggests that Icelandic Alaria esculenta-based extracts produced by PEF could be used as potential ingredients for natural cosmetic and cosmeceutical formulations.

Monthly Variation and Ultraviolet Stability of Mycosporine-like Amino Acids from Red Alga Dulse Palmaria palmata in Japan

Mycosporine-like amino acids (MAAs) are the natural ultraviolet (UV)-absorbing compounds from micro- and macro-algae. The MAAs in algae change with the environmental conditions and seasons. We previously determined an efficient extraction method of MAAs from red alga dulse in Usujiri (Hokkaido, Japan) and revealed monthly variation of MAA in 2019. Dulse samples in 2019 for MAA preparation were suitable from late February to April. In this study, to confirm the suitable timings to extract MAAs from Usujiri dulse, we also investigated the monthly (from January to May) variation of MAA content in 2020. There were the most MAAs in the sample on 18 March (6.696 µmol g−1 dry weight) among the samples from January to May 2020. From two years of investigation, we deduce that samples of Usujiri dulse from late February to early April were suitable for MAA preparation. The UV stability of the two major purified MAAs in Usujiri dulse—palythine and porphyra-334—was tested. The two MAAs and 2-hydroxy-4-methoxybenzophenone were stable for up to 12 h under a 312 nm lamp at 200 µW cm−2, but 2-ethylhexyl-4-methoxycinnamate formed a cis/trans-mixture in a short time. The data in this study show the suitable sampling period for Usujiri dulse and the possible application for UV protection from food and cosmetics.

An Assessment of Selected Nutritional, Bioactive, Thermal and Technological Properties of Brown and Red Irish Seaweed Species

Irish edible brown (Himanthalia elongata—sea spaghetti, Alaria esculenta—Irish wakame) and red seaweeds (Palmaria palmata—dulse, Porphyra umbilicalis—nori) were assessed for nutritional (proximate composition; salt; pH; amino acid; mineral and dietary fibre contents); bioactive (total phenolic content (TPC) and in vitro antioxidant activity (DPPH and FRAP)); thermal (thermogravimetric analysis (TGA)); and technological (water holding capacity (WHC), oil holding capacity (OHC) and swelling capacity (SC)) properties. Red seaweeds had higher (p < 0.05) protein levels, whereas brown seaweeds possessed higher (p < 0.05) moisture, ash, insoluble and total dietary fibre contents. Nori had the lowest (p < 0.05) salt level. Seaweed fat levels ranged from 1 to 2% DW. Aspartic and glutamic acids were the most abundant amino acids. The total amino acid (TAA) content ranged from 4.44 to 31.80%. Seaweeds contained numerous macro (e.g., Na) and trace minerals. The TPC, DPPH and FRAP activities followed the order: sea spaghetti ≥ nori > Irish wakame > dulse (p < 0.05). TGA indicated maximum weight loss at 250 °C. Dulse had the lowest (p < 0.05) WHC and SC properties. Dulse and nori had higher (p < 0.05) OHC than the brown seaweeds. Results demonstrate the potential of seaweeds as functional food product ingredients.

Роль водорослей-макрофитов в биоремедиации от нефтепродуктов Кольского залива Баренцева моря

Выполнена оценка вклада макроводорослей в очистку от дизельного топлива Кольского залива Баренцева моря. В основу расчётов положены результаты: 1) экспедиционных наблюдений последних лет о запасах, распределении и биомассе водорослей-макрофитов отделов Chlorophyta и Rhodophyta и класса Phaeophyceae из отдела Ochrophyta, обитающих в трёх частях залива; 2) лабораторных исследований по способности макроводорослей Ascophyllum nodosum, Fucus vesiculosus, F. distichus, F. serratus, Saccharina latissima, Palmaria palmata и Ulvaria obscura к нейтрализации токсического действия дизельного топлива. Показано, что общий вклад у исследованных водорослей в биоремедиацию от дизельного топлива в заливе составляет 312 кг в сутки. Выявлены различия в поглощающей способности у водорослей-макрофитов. Так, наиболее эффективно процесс осуществляет S. latissima, минимальная эффективность участия в биоремедиации определена у U. obscura. Сделан вывод о том, что имеющиеся литоральные и сублиторальные заросли морских макроводорослей Кольского залива являются важным элементом в процессе профилактической, повседневной очистки вод залива от нефтепродуктов. Включение в расчёты данных о способности к нейтрализации дизельного топлива у других представителей фитобентоса залива может увеличить роль водорослей-макрофитов в очистке прибрежных морских акваторий от нефтепродуктов. Сделан вывод, что заросли бурых водорослей — важная составляющая системы репарации и гомеостаза в прибрежных экосистемах. Уничтожение даже части природных сообществ водорослей может изменить баланс, существующий в экосистеме.

KANDUNGAN PROTEIN DAN KARBOHIDRAT PADA MAKROALGA DI PANTAI SEPANJANG, YOGYAKARTA

Kandungan protein dan karbohidrat pada makroalga diperlukan untuk mengoptimalkan pemanfaatan makroalga di Pantai Sepanjang. Penelitian ini bertujuan untuk mengetahui kandungan protein dan karbohidrat pada makroalga di Pantai Sepanjang, Yogyakarta. Penelitian ini dilakukan pada bulan Agustus-September 2020 di Pantai Sepanjang, Yogyakarta. Materi penelitian ini meliputi makroalga jenis Ulva lactuta, Palmaria palmata, Sargassum crassifolium, Gelidium spinosum, Gelidiella acerosa, dan Gracilaria verrucosa. Sampel makroalga secara purposive sampling pada zona intertidal Pantai Sepanjang. Analisis kandungan protein menggunakan metode Biuret, sedangkan analisis kandungan karbohidrat menggunakan metode by difference. Hasil menujukkan bahwa kandungan protein dan karbohidrat tertinggi terdapat pada G. spinosum di bagian tengah Pantai Sepanjang masing-masing sebesar 3,08% dan 19,38%. Berdasarkan hasil tersebut, G. spinosum memiliki potensi untuk dikembangkan dalam berbagai produk olahan dengan penelitian lebih lanjut.

AKTIVITAS ANTIOKSIDAN BERBAGAI JENIS MAKROALGA DI PANTAI SEPANJANG, KABUPATEN GUNUNGKIDUL, YOGYAKARTA (Antioxidant Activities in Various Types of Macroalgae at Sepanjang Beach, Gunungkidul District, Yogyakarta)

Penelitian ini bertujuan untuk mengetahui aktivitas antioksidan berbagai jenis makroalga di Pantai Sepanjang, Kabupaten Gunungkidul, Yogyakarta. Penelitian ini dilaksanakan di Pantai Sepanjang, Kabupaten Gunungkidul, Yogyakarta pada bulan Agustus 2020. Jenis makroalga yang ditemukan pada saat penelitian antara lain Ulva lactuca, Palmaria palmata, Sargassum crassifolium, Gelidium spinosum, Gelidiella acerosa, dan Gracilaria verrucosa. Metode yang digunakan dalam penelitian ini adalah deskriptif eksploratif. Pengambilan sampel makroalga dilakukan secara purposive sampling meliputi bagian timur, tengah dan barat Pantai Sepanjang. Analisis aktivitas antioksidan menggunakan metode DPPH (1,1-diphenyl-2-picrylhydrazyl). Hasil analisis menunjukan bahwa potensi aktivitas antioksidan tertinggi terdapat pada Gelidiella acerosa yang berada di bagian tengah Pantai Sepanjang dengan nilai IC50 sebesar 22,407 g/ml. This research aimed to analyze antioxidant activities from various types of macroalgae. Sample collection was taken at Sepanjang Beach, Gunungkidul District, Yogyakarta in August 2020. Various types of macroalgae were found are: Ulva lactuca, Palmaria palmata, Sargassum crassifolium, Gelidium spinosum, Gelidiella acerosa, and Gracilaria verrucosa. A method of descriptive exploratory was used in this research. Macroalgae samples were collected by purposive sampling from the eastern, central and western area of Sepanjang Beach. Antioxidant activities were carried out using DPPH method. The results showed that fresh Gelidiella acerosa which is located in the middle of Sepanjang Beach, has the highest antioxidant activities with IC50 value 22.407 g ml-1.

Seaweed Supplementation Failed to Affect Fecal Microbiota and Metabolome as Well as Fecal IgA and Apparent Nutrient Digestibility in Adult Dogs

The present study investigated in dogs the dietary effects of intact seaweeds on some fecal bacterial populations and metabolites, fecal IgA and apparent total tract digestibility (ATTD). Ten healthy adult dogs were enrolled in a 5 × 5 replicated Latin square design to evaluate five dietary treatments: control diet (CD); CD + Ascophyllum nodosum; CD + Undaria pinnatifida; CD + Saccharina japonica; CD + Palmaria palmata (n replicates per treatment = 10). Seaweeds were added to food at a daily dose of 15 g/kg. The CD contained silica as a digestion marker. Each feeding period lasted 28 d, with a 7 d wash-out in between. Feces were collected at days 21 and 28 of each period for chemical and microbiological analyses. Fecal samples were collected during the last five days of each period for ATTD assessment. Dogs showed good health conditions throughout the study. The fecal chemical parameters, fecal IgA and nutrient ATTD were not influenced by algal supplementation. Similarly, microbiological analyses did not reveal any effect by seaweed ingestion. In conclusion, algal supplementation at a dose of 15 g/kg of diet failed to exert noticeable effects on the canine fecal parameters evaluated in the present study.

Nutritional Composition of the Atlantic Seaweeds Ulva rigida, Codium tomentosum, Palmaria palmata and Porphyra purpurea

Macroalgae are regarded as a healthy food due to their composition and nutritional properties. In this work, nutritional composition of two green (Ulva rigida, Codium tomentosum) and two red (Palmaria palmata, Porphyra purpurea) edible seaweed was studied. Total lipids were measured gravimetrically as evaporated mass after petroleum-ether Soxhlet extraction of samples. In addition, fatty acid profile was determined by gas chromatography coupled to a flame ionization detector (GC-FID). Results showed that all studied species were accounted for very low levels of lipids (<1% dw), but levels of unsaturated fatty acids oleic, linoleic, and linolenic acids were present at high concentrations, with P. palmata displaying the highest quantities (>200 mg C18:1/g extract). In parallel, proteins were quantified following the macro-Kjeldahl method. In this analysis, red algae, especially P. purpurea, showed significant protein content up to 30% DW. Total organic acids were found by ultra-filtration liquid-chromatography coupled to an amperometry detector (UFLC-PAD) after an acid extraction, P. purpurea being the algae with the higher organic acid content (10.61% dw). Minerals were identified and quantified by inductively coupled plasma atomic emission spectroscopy (ICP-OES), suggesting that both algae groups are rich in K and Mg (>15 g/kg), but U. rigida also displayed a remarkable iron content (>1 g Fe/kg). Other detected minerals in minor concentrations were Ca, P or F. Altogether, results corroborate that these edible algae are a good source of nutrients in accordance with literature.

The anti-bacterial effect of phenolic compounds from three species of marine macroalgae

Scania AE, Chasani AR. 2021. The anti-bacterial effect of phenolic compounds from three species of marine macroalgae. Biodiversitas 22: 3412-3417. Bacterial infection is still a serious problem in human health due to many bacteria that are resistant to synthetic antibiotics. Natural antibiotics are needed for substituting synthetic antibiotics such as antibiotics derived from marine macroalgae. Marine macroalgae respond to extreme environmental conditions by producing secondary metabolites containing bioactive substances. Bioactive substances such as phenolic compounds in marine macroalgae may have an antibacterial effect on bacteria. Our research was aimed to detect the presence of phenolic compounds in three species of marine macroalgae (Ulva lactuca (Chlorophyta), Sargassum polycystum (Phaeophyta), Palmaria palmata (Rhodophyta)), and also to determine the most effective inhibition of phenols-contained extracts of marine macroalgae to the growth of Escherichia coli and Salmonella typhi. Our research was conducted through field sampling for collecting samples and laboratory work for identifying and extracting samples including qualitative testing of phenolic compounds, rejuvenating bacteria, preparing the tested bacteria, and determine the inhibition index of extracts against E.coli and S.typhi. Our results indicated that the extract of U. lactuca, S. polycystum, and P.palmata contained phenolic compounds. Phenols-contained extract of Sargassum polycystum is the most effective in inhibiting the growth of E. coli and S. typhi. The incubation temperature, the type of bacteria influence the antibacterial activity of marine macroalgae.