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This capstone project is a completed draft of an illustrated field guide of Southern California seaweeds. The purpose of this was to create a region-specific and user-friendly guide for readers to learn about local seaweeds. This was done by collecting life specimens and illustrating them by hand with watercolor. The illustrations were digitized and put into a draft, along with supporting information about each species. The completed draft will be prepared and submitted for publication in print.

AbstractThe exploration of endophytic fungi associated with seaweeds has garnered significant interest due to their crucial ecological functions and potential as sources of valuable bioactive compounds. In this study, we isolated and identified endophytic fungi from the brown seaweed Dictyopteris pacifica, collected from the intertidal zone of Yeongdoek, Gyeongsangbuk-do in Korea. Through morphological examination and molecular phylogenetic analysis using multiple molecular markers, including ITS, LSU, SSU, TEF1, TUB2, and RPB2 sequences, we identified three fungal species not previously recorded in Korea: Emericellopsis fuci, Neoarthrinium lithocarpicola, and Periconia chimonanthi. Detailed descriptions of morphological characteristics and phylogenetic analyses are provided. This study represents the first report of these endophytic fungi isolated from D. pacifica in Korea, thereby enhancing the understanding of the diversity of seaweed-associated endophytic fungi in the region. [ABSTRACT FROM AUTHOR]

Phase shifts from hard coral to macroalgae have led to the formulation of a top-down herbivory paradigm, whose assumption is that a reduction in herbivory is the primary driver of these changes. Caribbean parrotfish from Scarus and Sparisoma genera are usually known as main reef herbivorous. Yet, they are a diverse group of organisms that perform multiple functions, including the bioerosion of reef structures. Generalizing functions at the group level likely explains why the direct effects of parrotfish on macroalgae regulation are not always evident. In this study, we tested the hypothesis that parrotfish potential functions are strongly linked to the habitat's benthic characteristics. Furthermore, we expect that the parrotfish bioerosion potential will be highly sensitive to changes in benthic conditions, while herbivory will be more robust. We conducted in situ benthic and parrotfish surveys across the diverse reefscape of the remote Alacranes Reef, the most extensive system in the Gulf of Mexico. Both bioerosion and herbivory potential were highest in the most complex and structured sites, while only macroalgae removal was high in deep low-coral cover sites dominated by fleshy macroalgae. Interestingly, both functions were highly diminished in shallow and reticulated inner reefs dominated by turf algae and cyanobacteria, suggesting that even the herbivory function can be depleted under unfavorable benthic conditions. Our findings highlight the need to reconsider parrotfish management strategies to account for the specific roles of different species and consider reciprocal benthic-fish interactions. [ABSTRACT FROM AUTHOR]

Simple Summary: Diabetes mellitus is becoming an increasingly serious health issue, and the bioactive compounds found in marine algae may offer promising options for its management. These compounds include polysaccharides, polyphenols, unsaturated fatty acids, and dietary fiber, all of which have the potential to disrupt glucose and lipid metabolism disorders. However, more research is needed to understand how these compounds work, determine the best dosages, and find effective delivery methods for managing diabetes. While substances derived from algae, such as fucoidan and red algal polysaccharides, show potential, further studies are required to identify specific beneficial compounds, establish safe consumption levels, and assess their long-term safety. Additionally, the low bioavailability of algae and the impact of their cell walls on nutrient absorption need to be addressed. Despite these challenges, adding algae to a balanced diet could serve as an alternative to traditional diabetes treatments, with the possibility of broader medical applications once their safety and effectiveness are validated. Diabetes mellitus (DM) is becoming increasingly prominent, posing a serious threat to human health. Its prevalence is rising every year, and often affects young people. In the past few decades, research on marine algae has been recognized as a major field of drug discovery. Seaweed active substances, including algal polysaccharides, algal polyphenols, algal unsaturated fatty acids, and algal dietary fiber, have unique biological activities. This article reviews the effects and mechanisms of the types, structures, and compositions of seaweed on inhibiting glucose and lipid metabolism disorders, with a focus on the inhibitory effect of active substances on blood glucose reduction. The aim is to provide a basis for the development of seaweed active substance hypoglycemic drugs. [ABSTRACT FROM AUTHOR]

Vegans have lower risks of some health problems such as ischemic heart disease, type 2 diabetes, and some cancers. However, they are at high risk of some nutrient deficiencies, including iodine, because plant foods are poor sources of the nutrient, except for seaweed. Also, some vegans refuse to use iodized salt or dietary supplements containing iodine. Urinary iodine concentration among vegans, indicative of mild, moderate, or severe deficiency, is common among a large percentage of vegans in many countries. Similarly, there is a high incidence of inadequate iodine concentration in the breast milk of vegan mothers. This article provides information on the iodine content of brown, red, and green algae. Some seaweed types, especially brown algae, contain very high amounts of iodine, and so, soaking and blanching are necessary to reduce the iodine content to safe levels to prevent iodine toxicity. This article focuses on seaweed and its use as a source of iodine. Because some vegans do not use iodized salt or iodine-containing supplements and because plant foods are poor sources of iodine, seaweed is a potential source of the nutrient, but to reduce the risk of toxicity, soaking and blanching are needed to dispose of excess iodine. [ABSTRACT FROM AUTHOR]

Algae are a complex source of crucial nutrients, including proteins, minerals, vitamins, and carbohydrates. The use of marine algae, specifically Sargassum species, Gracilaria species, and Spirulina species, as feed ingredients in poultry feed was examined in the current research. This study's aims were to carry out lipid profiling, proximate analysis, and heavy metal toxicity testing, as well as to evaluate the presence of hazardous hydrocarbons in the algae and investigate the effect of the fatty acid profile of Sargassum species on broilers. The proximate analysis was conducted on the algae types containing considerable quantities of fats and proteins and a sizable quantity of omega-3 fatty acids. This research assessed the productive effectiveness of broilers with 2.5%, 6%, and 10% algal additions in their diet. Fatty acid profiling of Sargassum species was performed at 1% and 2% levels in the bursa, fat pads, heart, liver, spleen, thymus, thighs, and breast. The findings showed no significant differences in the development performance or feed utilization efficiency of broilers with 2.5%, 6%, and 10% algae supplementation in their diet. The results of fatty acid profiling showed changes in the heart, liver, and spleen at 1% and 2% supplementations levels. However, this research concludes that if algae partially replaces the imported feed proteins used in animal feed, then these can achieve maximum beneficial effects on poultry health and performance. Algae are sustainable, easy to produce, and cost-effective sources of nutrients and contain numerous bioactive compounds, which will contribute to sustainability and food safety. [ABSTRACT FROM AUTHOR]

The disappearance of canopy-forming algae in coastal habitats exposes crustose coralline algae (CCA) to varying light conditions during the transition from foliose macroalgal habitats to barren ground by physical, chemical, or biological interaction. We hypothesized that the sudden increase in light intensity, resulting from the absence of canopy-forming algae, leads to photodamage in CCA related to inhibition of growth. To test this, a 4-week indoor incubation experiment was conducted under different light intensities (20-, 60-, 120-, and 250-μmol photons m−2 s−1). Results revealed that CCA can acclimate to limited light environments, with the efficiency of PSII significantly reduced at higher light levels. Photoprotective mechanisms were activated under persistent stress, leading to a reduction in encrusting area and CCA bleaching. This suggests that CCA coexist with canopy-forming algae in environments with sufficient light exposure, benefiting from the shade provided. However, if directly exposed to light due to the disappearance of canopy-forming algae, CCA faces extreme light stress and potential disappearance. [ABSTRACT FROM AUTHOR]

Seaweeds are widely assumed to be phenotypically plastic across hydrodynamic gradients, yet while many marine macroalgae exhibit intraspecific phenotypic variation that correlates with flow, researchers often fail to test whether such variation is due to plasticity or another mechanism, such as local adaptation. In this minireview, we considered mechanisms for sensing flow in seaweeds that could facilitate adaptive phenotypic plasticity across hydrodynamic gradients. We then reviewed the literature from 1900 to 2024 to see how often phenotypic variation and plasticity across hydrodynamic gradients had been observed and demonstrated in different groups of seaweeds. In the last 124 years, phenotypic variation and plasticity in response to flow have been well documented in brown algae but scarcely documented in red and green algae. This could suggest that brown algae are better able to sense and respond to flow than red and green algae, perhaps due to the intercalary meristem of many brown algae, including most kelps. However, this skewed distribution could also be the result of publication bias, as most studies involving flow have been conducted on brown algae. Only 30% of 141 papers specifically investigated if observations of phenotypic variation along hydrodynamic gradients were due to plasticity. To date, phenotypic plasticity in response to flow has been demonstrated in 20 brown algal species, five red algal species, and two green algal species. Thus, the assumption that phenotypic plasticity to flow is common across seaweeds is not particularly well supported by the literature. Mechanisms underlying plasticity to flow are poorly understood and remain a critical avenue for future research. [ABSTRACT FROM AUTHOR]

The marine algae Ulva spp. are commonly used as model biofouling organisms. As biofouling studies are primarily conducted using field-collected specimens, factors including species identity, seasonal availability, and physiological status can hinder the replicability of the results. To address these limitations, a protocol was developed for the on-demand laboratory culture and release of Ulva zoospores. The biofouling potential of laboratory-cultured and field-collected Ulva blades was compared using a waterjet. No significant differences were found between field and laboratory-cultured samples in either spore adhesion (before waterjet) or the proportion of spores retained after waterjet exposure. However, there was significant variability within each session type in pre- and post-waterjet exposures, indicating that spore adhesion and retention levels vary significantly among trial runs. In addition, all our laboratory cultures were Ulva Clade C (LPP complex). In contrast, our field samples contained a mix of Ulva Clade C, U. compressa clade I, and U. flexuosa Clade D. This protocol for on-demand production of Ulva spores can improve biofouling research approaches, enables comparison of results across laboratories and regions, and accelerate the development of anti-biofouling strategies. [ABSTRACT FROM AUTHOR]

Vegetated coastal marine ecosystems are projected to expand northwards in the Arctic due to climate change, but the mechanisms for this expansion are complex and nuanced. Macroalgal biomass in the littoral areas of Svalbard has been increasing, but data at the glacier fronts are very scarce. In this study, we use hydroacoustics and video validation from an unmanned surface vehicle to survey macroalgal bed distribution along the coast of a High Arctic fjord (Billefjorden, Svalbard), including river bays and land- and sea-terminating glacier fronts, as well as oceanographic measurements to indicate physical drivers of macroalgal settlement. We found high variation of macroalgal coverage along the fjord coastline, with virtually no macroalgae in the river bays but abundant coverage in areas with little terrestrial runoff. Furthermore, the presence of kelp was found at the land-terminating glacier front which has recently retreated from the sea, which suggests the potential for rapid macroalgal establishment in newly available substrate following glacial retreat. These findings suggest large ecological implications throughout the Arctic, in which macroalgal expansion may lead to significant changes in the underwater coastal landscape and ecosystem. This study shows that the use of remote autonomous vehicles and hydroacoustic mapping with video validation has a high potential for sustainable and efficient ecological monitoring. [ABSTRACT FROM AUTHOR]

The consumers’ appreciation and preference for products containing seaweed, as a natural alternative to synthetic cosmetics, has been ever growing in recent years. They are subjected to high expectations in terms of contents, such as purified bio active substances. Seaweed’s chemical compounds’ effectiveness in cosmetics is already known and they are successfully applied as effective alternatives with visible benefits. The varying species of algae have numerous beneficial properties for the skin. The bio-activeness of their compounds, such as carbohydrates, proteins, phenolic compounds and pigments have been researched and proven to be safe for use in the cosmetic industry. The following overview will explore the proof of the biological properties and various applications of bio-active molecules, derived from seaweed and their application in the cosmetic industry. [ABSTRACT FROM AUTHOR]

Background: Seaweeds are macroalgae containing bioactive compounds that have positively impacted the biomedical field due to polysaccharides, sterols and glycolipids, showing a diverse range of pharmacological and biological properties. Eating a diet high in marine items will lessen the risk of developing diabetes, cancer and obesity. Purpose: The exploration of medically useful seaweeds is required to identify drugs and drug targets and reduce the risk of developing diseases. Methodology: The PubMed search was done with the MESH terms such as seaweed and Marine algae pharmacological activity results were obtained as 748 results. We filtered out the articles and entered key terms related to our area of interest to find the results. The seaweed species in India are listed with Tamil Nadu contributing the most and Orissa the least. The type of algae is also mentioned. Results: Marine algae have been employed in industry and medicine as a novel food with possible nutritional benefits. Furthermore, it has been demonstrated that marine algae are a rich source of naturally occurring bioactive substances with activities such as anti-diabetic, hepatoprotective, antiviral, antifungal, antibacterial, antimicrobial, antioxidant, anti-inflammatory, anti-hypercholesterolemia and hypolipidemia. Conclusion: The current review focuses on the bioactivities and potential pharmaceutical activity of marine algae discovered in India. The present review article showed that there are many seaweeds of medical importance, and it is necessary to explore them to minimize disease progression and prolong the individual's survival. [ABSTRACT FROM AUTHOR]

BACKGROUND: Conventional petroleum‐based packaging films cause severe environmental problems. In the present study, bio‐edible film was introduced as being safe to replace petroleum‐based polymers. A food application for edible sachets and a composite edible film (EF) from marine algae, Gracilaria fisheri (GF) extract, were proposed. RESULTS: Carbohydrates were the most prevalent component in fresh GF fronds. Under neutral conditions comprising 90 °C for 40 min, the structure of the extract was determined by Fourier transform infrared to be a carrageenan‐like polysaccharide. Glycerol was the best plasticizer for EF formation because it had the highest tensile strength (TS). The integration of gelatin into the algal composite film with gelatin (CFG) was validated to be significant. The best casting temperatures for 2 h were 70 and 100 °C among the four tested temperatures (25, 60, 70 and 100 °C). Temperatures did not result in any significant (P ≤ 0.05) differences in any character (color values, TS, water vapor permeability, oxygen transmission, thickness and water activity), except elongation at break. Visually, the CFG had a slightly yellow appearance. The best‐to‐worst order of film stability in the three tested solvents was oil, distilled water (DW) and ethanol. Its stability in ethanol (0–100%), temperature of DW (30–100 °C) and pH (3–7 in DW) demonstrated inverse relationships with the concentration or different conditions, except for pH 8–10 in DW. All treatments were significantly (P ≤ 0.05) different. CONCLUSION: The novel material made from polysaccharides from algae, G. fisheri, was used to improve EF. The edible sachet application is plausible from the EF. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

This study set out to provide a preliminary assessment of nutritional profiles of five selected New Zealand macroalgae to investigate the potential of landcultivated Ulva spp. The New Zealand seaweeds species, selected from a limited range, were either collected from the wild (Pyropia plicata from Tauranga and Kaikōura), or were sourced from commercial wild harvest suppliers (Macrocystis pyrifera and Undaria pinnatifida), and were compared to land-based cultivated Ulva species (Ulva ralfsii and Ulva stenophylloides). Species were assessed for their content of crude protein, total lipids, carbohydrates, fibers, amino acids, mineral profiles, heavy metals and antioxidant capacity (Oxygen Radical Absorbance Capacity, ORAC). The two cultivated Ulva spp. had the highest crude protein content of the six seaweeds analyzed (approximately 21% dw, N×6.25), as expected with nutrient supplemented cultivation. They also had the highest total, essential and branched chain amino acid quantities (151, 70, and 29 mg/g for U. stenophylloides and 138, 62, and 27 mg/g for U. ralfsii). Though the two Ulva spp. were grown to the same cultivation specifications, they varied in carbohydrate and total fiber content (U. stenophylloides: 63% and 62%; U. ralfsii: 39% and 40%, respectively). Pyropia plicata collected in Kaikōura had the highest carbohydrate levels (65%) though not the highest total fiber. Both P. plicata had the highest trace minerals (417 mg/kg and 720 mg/kg for Kaikōura and Tauranga P. plicata respectively). All seaweeds analyzed showed no lipophilic antioxidants, though the two Phaeophyceae had the highest hydrophilic antioxidant content at 115 TE and 168 TE for Macrocystis pyrifera and Undaria pinnatifida, respectively. This paper provides a preliminary indication of the relative nutritional attributes of a range of potential New Zealand seaweed aquaculture targets benchmarked against sealettuce (Ulva spp.). [ABSTRACT FROM AUTHOR]

The recognition and use of algae in the very trend-driven cosmetic industry is progressively increasing. Up to now, the main focus was on large seaweeds and a limited number of microalgae. However, motile microalgae, flagellates, remain underscored in this aspect, although some of them are utilized commercially. Flagellates from different taxonomic groups occupy various habitats and contain bioactive high-value multifunctional compounds, some of which are novel. Moreover, they may simultaneously produce different substances, which together with the development of downstream processing technologies, makes them a promising source for modern biotechnology. The present review covers data on 411 strains, 251 species from 110 genera from 6 phyla, and is oriented generally towards less explored flagellates. It demonstrates their great potential as bearers of interesting novel compounds that can be beneficially applied in modern cosmetics. Safety aspects of both sources and products are also discussed. Considering the gaps in the knowledge, the necessity to expand the research on both well-known and yet unexplored microalgae is shown, encouraging the development of upstreaming processes, including phycoprospecting. Last but not least, this paper outlines the role of living culture collections and of using good taxonomic expertise before running the biochemical tests, cultivation, and bioengineering experiments. [ABSTRACT FROM AUTHOR]

Bioremediation using tropical marine algae provides cost effective and eco-friendly alternative mean of removing toxic and harmful substances from the environment. Bioremediation is an important tool in sustainable environmental management and protection. This study examined the productivity and bioremediation potential of Nannochloropsis oculata and Porphyridium cruentum in Water Soluble Fraction (WSF) of petroleum fuels by investigating the growth of Nannochloropsis oculata and Porphyridium cruentum at 0%, 10% 20% 30% 40% 50% 75% 100% of WSF of kerosene, diesel, and gasoline. Growth was monitored optically every two days for fourteen days using 721 Visible Spectrophotometer. Productivity was measured using prescribed procedure. Bioremediation potential of test algae were examined using standard method for the GC analysis of diesel range organics in 100% WSFs. The minimum growth for both species was recorded at 100% in all the fuels. The maximum growth of Porphyridium cruentum was obtained at 10% in all fuels, while the maximum growth of Nannochloropsis oculata was obtained at 30% in both kerosene and gasoline and at 50% in diesel. Whereas Porphyridium cruentum was greatly inhibited by all fuels, Nannochloropsis oculata was stimulated at lower concentration of the fuels. Nannochloropsis oculata proved more efficient for bioremediation of the petroleum fuels with 84.58%, 65.51% and 70.77% removal efficiency for kerosene, diesel and gasoline respectively, while Porphyridium cruentum was 58.94%, 46.64% and 56.67% respectively. Nannochloropsis oculata is a very strong and reliable candidate for bioremediation of petroleum hydrocarbons and should be subjected to further examination for sustainable and eco-friendly remediation of petroleum pollution. In this study, bioremediation of 100% Water Soluble Fraction (very high concentration) of the three most commonly used petroleum fuels (gasoline, diesel, kerosene) were examined. The bioremediation potential of the test algae were examined simultaneously in three petroleum fuels to enhance comparative assessment and to reduce the effect of environmental changes. This study identifies specific tropical marine alga that has high biomass productivity and bioremediation efficiency in tropical marine or coastal waters polluted with very high concentration of WSF of petroleum hydrocarbons. The result of this study is recommended for adoption by the bioremediation industries for the removal of high concentration of WSF of petroleum hydrocarbons in tropical marine waters and industrial waste waters. It may also be subjected to further examination. [ABSTRACT FROM AUTHOR]

Simple Summary: Seaweed aquaculture plays an important role in global food supply, but single-species intensive seaweed aquaculture has problems related to simple industrial structure and risk susceptibility. Therefore, there is an urgent need to establish a series of large-scale seaweed rotational culture models to address the current industrial challenges in algae culture. The culture of macroalgae is mainly affected by environmental factors such as water temperature and light. In this study, we constructed a rotational culture model by carrying out experiments with three species of macroalgae, observing in situ their photosynthetic activity responses to different temperature and light conditions. The results of this study can provide a theoretical basis for the establishment of large-scale rotational aquaculture, which can effectively improve the ecological and economic value of macroalgae aquaculture. Seaweed farming has made outstanding contributions to food supply and the restoration of the ecological environment despite the limitations in production and ecological effects due to the current intensive farming of single algae species. These limitations can be overcome by selecting suitable algal species based on their physiological characteristics and by constructing a large-scale seaweed rotation model. This study carried out a trial culture in aquaculture sea areas, and performed in situ monitoring of the environmental conditions and physiological characteristics of Saccharina japonica, Hizikia fusiformis, and Gracilariopsis lemaneiformis. Additionally, a comparative analysis of the three macroalgae at different times was conducted to determine their response characteristics to environmental factors. The results showed that: (1) The three macroalgae had varying light tolerance. The effective quantum yield of Hizikia fusiformis and Gracilariopsis lemaneiformis remained unchanged during the changes in light environment, while that of Saccharina japonica first decreased and then recovered. (2) The relative electron transport rates of the three macroalgae were significantly different under different temperature conditions. Hizikia fusiformis and Saccharina japonica exhibited the highest relative electron transport rates (70.45 and 106.75, respectively) in May (20.3 °C). Notably, Gracilariopsis lemaneiformis demonstrated good growth and exhibited the highest relative electron transport rate (93.07) in September (27.5 °C). These findings collectively support the feasibility of establishing a macroalgae rotation model. Based on the combined environmental conditions of the seas in Shandong, Zhejiang, and Fujian, a macroalgae rotation model was proposed. The application of this model in the construction of artificial seaweed farms in marine ranches can provide a stable output of large-scale seaweed production and ecological benefits. [ABSTRACT FROM AUTHOR]

CRISPR-Cas systems are adaptive immune mechanisms present in most prokaryotes that play an important role in the adaptation of bacteria and archaea to new environments. Shewanella algae is a marine zoonotic pathogen with worldwide distribution, which accounts for the majority of clinical cases of Shewanella infections. However, the characterization of Shewanella algae CRISPR-Cas systems has not been well investigated yet. Through whole genome sequence analysis, we characterized the CRISPR-Cas systems in S. algae. Our results indicate that CRISPR-Cas systems are prevalent in S. algae, with the majority of strains containing the Type I-F system. This study provides new insights into the diversity and function of CRISPR-Cas systems in S. algae and highlights their potential role in the adaptation and survival of these marine pathogens. [ABSTRACT FROM AUTHOR]

Environmental context: Seaweeds are known to accumulate high levels of arsenic, and cellular concentrations may reach several orders of magnitude higher than that of the surrounding environment. Arsenic may be methylated by seaweed cells and further metabolised to water-soluble arsenic-containing sugars through unknown pathways. Whether these compounds are the result of a detoxification process or are produced with a biological purpose remains to be seen. Rationale: Seaweeds are known to accumulate high levels of arsenic, which may be subsequently metabolised to small, methylated compounds or become incorporated into large biological molecules such as arsenosugars. The mechanism of arsenosugars production in macroalgae is still largely unknown. Method: This study reports the arsenic speciation of 13 brown, red and green macroalgae collected in May 2021 and February 2022. Water-soluble arsenic speciation was measured using high-performance liquid chromatography–inductively coupled plasma–mass spectrometry (HPLC-ICP-MS) after extraction with a 3% (v/v) hydrogen peroxide solution. Results: Arsenosugars were found to account for the majority of the extracted arsenic in all seaweed samples (>50%), with only small amounts of dimethylarsinate and monomethylarsonate present. Levels of toxic iAs were also low (−1). Sulfur-containing arsenosugars were the dominant arsenicals in brown macroalgae, whereas the phosphate ribose was most abundant in red and green. Discussion: The majority of seaweed species appear to have the ability to synthesise all four arsenosugar derivatives; however, it is unclear why some are produced in higher abundances. The production of arsenosugars may be an efficient way of excluding arsenic from the cytosol, or may serve as useful components in the cell wall matrix, as extremely high levels can be tolerated by the seaweed with no ill effects. AsSug-gly and AsSug-PO4 were detected in every sample analysed, which might suggest that AsSug-gly is the starting point for AsSug-PO4, which could be formed by AsSug-gly binding to phosphate-containing lipids in the cell membrane. Further studies should use both imaging and speciation techniques to investigate the formation of arsenosugars. Environmental context. Seaweeds are known to accumulate high levels of arsenic, and cellular concentrations may reach several orders of magnitude higher than that of the surrounding environment. Arsenic may be methylated by seaweed cells and further metabolised to water-soluble arsenic-containing sugars through unknown pathways. Whether these compounds are the result of a detoxification process or are produced with a biological purpose remains to be seen. (Image credit: Rebecca Sim.) [ABSTRACT FROM AUTHOR]

In this study, arsenic (As) speciation was investigated in the freshwater alga Chlamydomonas reinhardtii treated with 20 μg/L arsenate using fractionation as well as ICP-MS/ESI-MS analyses and was compared with the known As metabolite profile of wild-grown Saccharina latissima. While the total As accumulation in C. reinhardtii was about 85% lower than in S. latissima, the relative percentage of arsenolipids was significantly higher in C. reinhardtii (57.0% vs. 5.01%). As-containing hydrocarbons and phospholipids dominated the hydrophobic As profile in S. latissima, but no As-containing hydrocarbons were detectable in C. reinhardtii. Instead for the first time, an arsenoriboside-containing phytol (AsSugPhytol) was found to dominate the hydrophobic arsenicals of C. reinhardtii. Interestingly, this compound and its relatives had so far been only found in green marine microalgae, open sea plankton (mixed assemblage), and sediments but not in brown or red macroalgae. This compound family might therefore relate to differences in the arsenic metabolism between the algae phyla. [ABSTRACT FROM AUTHOR]

A growing interest in more sustainable and alternative food sources has brought seaweed and macroalgae to the spotlight for the general worldwide cuisine. Algae are often praised for their high nutritional value and are rich in potassium, calcium, and magnesium. Abundant in base precursors, algae are particularly interesting from an acid-base perspective. Their unique biochemical composition suggests a low potential renal acid load (PRAL), which is a commonly used estimate for the amount of acid or base a certain food produces in humans. Here, we analyzed the PRAL value of n = 106 macroalgae. Results suggested a strong alkalizing potential, with a mean PRAL value of −86.76 mEq/100 g. The lowest PRAL values were found for Laminaria ochroleuca (−286.78 mEq/100 g), Gelidium micropterum (−268.46 mEq/100 g), and Palmaria palmata (−259.16 mEq/100 g). We observed a strong inverse relationship of PRAL with algae's potassium content (Spearman's rho = −0.79, p < 0.001) and a moderate relationship with algae's calcium content (Spearmen's rho: −0.34, p < 0.001). Our data point at a potential role for several macroalgae as potent alkalizing marine drugs and suggest that a 10 g edible portion of some algae alone could contribute to a substantial PRAL reduction of up to −28.68 mEq. This might be of particular importance for individuals who benefit from a more alkaline diet and warrants further investigation in future studies. [ABSTRACT FROM AUTHOR]

Nature derived compounds represent a valuable source of bioactive molecules with enormous potential. The sea is one of the richest environments, full of skilled organisms, where algae stand out due to their unique characteristics. Marine macroalgae adapt their phenotypic characteristics, such as chemical composition, depending on the environmental conditions where they live. The compounds produced by these organisms show tremendous potential to be used in the biomedical field, due to their antioxidant, anti-inflammatory, immunomodulatory, and anti-cancer properties. Cancer is one of the deadliest diseases in the world, and the lack of effective treatments highlights the urgent need for the development of new therapeutic strategies. This review provides an overview of the current advances regarding the anti-cancer activity of the three major groups of marine macroalgae, i.e., red algae (Rhodophyta), brown algae (Phaeophyceae), and green algae (Chlorophyta) on pancreatic, lung, breast, cervical, colorectal, liver, and gastric cancers as well as leukemia and melanoma. In addition, future perspectives, and limitations regarding this field of work are also discussed. [ABSTRACT FROM AUTHOR]

Non-communicable diseases (NCDs) represent a global health challenge, constituting a major cause of mortality and disease burden in the 21st century. Addressing the prevention and management of NCDs is crucial for improving global public health, emphasizing the need for comprehensive strategies, early interventions, and innovative therapeutic approaches to mitigate their far-reaching consequences. Marine organisms, mainly algae, produce diverse marine natural products with significant therapeutic potential. Harnessing the largely untapped potential of algae could revolutionize drug development and contribute to combating NCDs, marking a crucial step toward natural and targeted therapeutic approaches. This review examines bioactive extracts, compounds, and commercial products derived from macro- and microalgae, exploring their protective properties against oxidative stress, inflammation, cardiovascular, gastrointestinal, metabolic diseases, and cancer across in vitro, cell-based, in vivo, and clinical studies. Most research focuses on macroalgae, demonstrating antioxidant, anti-inflammatory, cardioprotective, gut health modulation, metabolic health promotion, and anti-cancer effects. Microalgae products also exhibit anti-inflammatory, cardioprotective, and anti-cancer properties. Although studies mainly investigated extracts and fractions, isolated compounds from algae have also been explored. Notably, polysaccharides, phlorotannins, carotenoids, and terpenes emerge as prominent compounds, collectively representing 42.4% of the investigated compounds. [ABSTRACT FROM AUTHOR]

The globally distributed marine alga Emiliania huxleyi has cooling effect on the Earth's climate. The population density of E. huxleyi is restricted by Nucleocytoviricota viruses, including E. huxleyi virus 201 (EhV-201). Despite the impact of E. huxleyi viruses on the climate, there is limited information about their structure and replication. Here, we show that the dsDNA genome inside the EhV-201 virion is protected by an inner membrane, capsid, and outer membrane. EhV-201 virions infect E. huxleyi by using fivefold vertices to bind to and fuse the virus' inner membrane with the cell plasma membrane. Progeny virions assemble in the cytoplasm at the surface of endoplasmic reticulum-derived membrane segments. Genome packaging initiates synchronously with the capsid assembly and completes through an aperture in the forming capsid. The genome-filled capsids acquire an outer membrane by budding into intracellular vesicles. EhV-201 infection induces a loss of surface protective layers from E. huxleyi cells, which enables the continuous release of virions by exocytosis. [ABSTRACT FROM AUTHOR]

Benefits of integrated shrimp/seaweed culture systems have been investigated; nevertheless, knowledge of the importance of microorganisms in the systems is limited. In the present study, we evaluated shrimp Litopenaeus vannamei under four experimental conditions: fed pelleted diet in the presence of Ulva lactuca with (UPE) and without water exchange (UPN) and fed only a pelleted diet with (PE) and without water exchange (PN). Bacterial communities present in shrimp, seaweed, and water were analyzed after 4 weeks of an experimental trial. Our results showed significantly lower shrimp final weight, weight gain, specific growth rate (SGR), and higher feed conversion ratio (FCR) with PN treatment compared to the rest of the treatments (P < 0.05). Seaweed resulted in lower relative abundance of Vibrio in the presence of shrimp (UPE and UPN) compared to monoculture (Ulv). Shrimp intestine presented lower Vibrio and significantly increased Sagittula and Lutimonas in treatments without water exchange. In the case of shrimp fed only pellet with water exchange (PE), a significantly higher relative abundance of Lucibacterium and Planctomicrobium genera was found compared to PN, UPE, and UPN treatments. The results suggest that the seaweed in a system with no water exchange is advantageous to promote water bacterial diversity, and that reduces the relative abundance of Vibrio in shrimp gut. Additionally, PERMANOVA analyses revealed that both seaweed presence and water exchange are significant factors in structuring the culture system microbiota (P < 0.001). The present study contributes to understanding the importance of microbial communities in shrimp/seaweed integrated aquaculture systems. [ABSTRACT FROM AUTHOR]

In this study investigation of accumulations of critical raw materials (cobalt (Co), antimony (Sb), vanadium (V), lanthanum (La) and tungsten (W)) from wastewater by using C. fracta were aimed. Besides, assessment of the potential health risks in terms of the use of organic fertilizer obtained from the macroalga to be harvested from the treatment were also aimed. Highest Co, Sb, V, La and W accumulations by algae in reactor were 125±6.2%, 201.25±10%, 318.18±15%, 357.97±18%, and 500±25%, respectively. When compared with control, Co, Sb, V, La and W in algae increased 2.25, 3.01, 4.18, 4.58, and 6 times, respectively. The algae was very high bioaccumulative for Co and La. Highest MPI was calculated as 3.94. Non-carcinogenic risk of CRMs according to different exposure types (ingestion, inhalation, and dermal) were calculated for man, woman and child. There is not any non-carcinogenic risk from the investigated exposure ways of algae as organic fertilizer. [ABSTRACT FROM AUTHOR]

In Hawaiʻi, native macroalgae or "limu" are of ecological, cultural, and economic value. Invasive algae threaten native macroalgae and coral, which serve a key role in the reef ecosystem. Spectroscopy can be a valuable tool for species discrimination, while simultaneously providing insight into chemical processes occurring within photosynthetic organisms. The spectral identity and separability of Hawaiian macroalgal taxonomic groups and invasive and native macroalgae are poorly known and thus were the focus of this study. A macroalgal spectroscopic library of 30 species and species complexes found in Hawaiʻi was created. Spectral reflectance signatures were aligned with known absorption bands of taxonomic division-specific photosynthetic pigments. Quadratic discriminant analysis was used to explore if taxonomic groups of algae and native versus invasive algae could be classified spectrally. Algae were correctly classified based on taxonomic divisions 96.5% of the time and by species 83.2% of the time. Invasive versus native algae were correctly classified at a rate of 93% and higher, although the number of invasive algal species tested was limited. Analyses suggest that there is promise for the spectral separability of algae investigated in this study by algal taxonomic divisions and native-invasive status. This study created a spectral library that lays the groundwork for testing the spectral mapping of algae using current airborne and forthcoming spaceborne imaging spectroscopy, which could have significant implications for coastal management. [ABSTRACT FROM AUTHOR]

As the body's largest organ, the skin is located at the internal and external environment interface, serving as a line of defense against various harmful stressors. Recently, marine-derived physiologically active ingredients have attracted considerable attention in the cosmeceutical industry due to their beneficial effects on skin health. Sargassum, a genus of brown macroalgae, has traditionally been consumed as food and medicine in several countries and is rich in bioactive compounds such as meroterpenoids, sulfated polysaccharides, fucoidan, fucoxanthin, flavonoids, and terpenoids. Sargassum spp. have various beneficial effects on skin disorders. They help with atopic dermatitis by improving skin barrier protection and reducing inflammation. Several species show potential in treating acne by inhibiting bacterial growth and reducing inflammation. Some species, such as Sargassum horneri, demonstrate antiallergic effects by modulating mast cell activity. Certain Sargassum species exhibit anticancer activity by inhibiting tumor growth and promoting apoptosis, and some species help with wound healing by promoting angiogenesis and reducing oxidative stress. Overall, Sargassum spp. demonstrate potential for treating and managing various skin conditions. Therefore, the bioactive compounds of Sargassum spp. may be natural ingredients with a wide range of functional properties for preventing and treating skin disorders. The present review focused on the various biological effects of Sargassum extracts and derived compounds on skin disorders. [ABSTRACT FROM AUTHOR]

Cellulose has been intensively investigated for biomedical applications, because of its excellent properties, like biodegradability, biocompatibility, abundant availability of renewable resources and cost-effectiveness. Among all sources of cellulose, marine macroalgae or seaweeds, are acquiring tremendous attention, due to their high availability around the world. Moreover, the atypical proliferation of some exotic macroalgae species represents a serious problem to the ecosystems, since their accumulation threatens native oceanic species and resources worldwide. Several studies already reported the successfully extraction of cellulose and its derivatives from brown, green and red macroalgae. The extracted cellulose properties vary according to the type of algae, their maturity and the used extraction methods. This review will cover the main methods used to extract cellulose from algae, focusing on more sustainable ones, as well as its further processing into the various cellulose derivatives. Electrospun nanofibers have revealed great potential for biomedical applications, such as delivery of therapeutic agents, tissue engineering, wound dressings and enzyme immobilization. Pure cellulose presents some drawbacks, such as limited solubility in organic solvents and its inability to fuse due to inter and intra-molecular hydrogen bonding. To overcome these limitations, cellulose derivatives, which includes microcrystalline cellulose, cellulose nanocrystals, cellulose nanofibers, cellulose acetate and carboxymethyl cellulose, have been extensively studied to generate electrospun fibers. Therefore, this review aims to explore the marine seaweeds as a promising source of cellulose and its derivatives, the extraction methodologies of these compounds, as well as to demonstrate the potential of nanofibers developed by electrospinning with algae-based cellulose for biomedical applications. [ABSTRACT FROM AUTHOR]

Dietary supplements are used for potential health benefits and are mainly intended to provide those nutrients that may be insufficiently consumed through regular dietary intake. They are mostly made from natural sources and are readily available in the form of capsules, tablets, or liquid form. Nowadays, omega-3 fatty acids (n-3 FAs) supplements are in high demand and have gained noteworthy popularity as the human body cannot produce them, and need to be administrated externally. They are polyunsaturated fatty acids (PUFA) characterized by at least one cis double bond at the third and fourth omega-end carbons, with primary examples being α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) and are classified as functional foods. The natural sources of these supplements include aquatic organisms like freshwater and marine fish, microalgae, seaweeds; nuts and seeds plant oils, and fortified foods. n-3 FAs, being biologically active molecules, are highly susceptible to oxidation due to double bonds in their long chains, leading to degradation over time, during storage. Various encapsulation systems, such as gels, emulsions, and powders, have been developed to effectively encapsulate PUFAs to enhance their chemical stability, dispersibility, and bioavailability. These quality control measures are essential to guarantee the effectiveness and safety of products containing n-3 FAs. This paper explores various sources of omega-3 fatty acid supplements and summarizes the multiple manufacturing techniques used for the production of these products. Additionally, the article tried to correlate quality aspects with the regulations for such products in an attempt to prevent exposure of consumers to harmful ingredients contained within these products. Lastly, potential recommendations for harmonizing the regulation and control of omega-3 supplements are proposed. [ABSTRACT FROM AUTHOR]

Technology in the meat industry is advancing to create healthier and more sustainable food. Incorporating micro- and macroalgae into meat products presents an exciting possibility for the meat sector to develop functional food, given that they serve as excellent natural sources of nutrients and bioactive compounds. This review aims to systematically outline the impact of incorporating whole algae and their extracts into various meat products, examining their effects on quality, physicochemical and functional properties, sensory characteristics, and potential for enhancing shelf life. Adding algae to meat products generally increased pH values, with variations influenced by concentration, type, initial pH, and storage time. The protein content was mainly unaffected, except for Nori and Chlorella. Algae contributed to lower moisture and higher ash content due to dietary fiber. While including algae improved water-holding capacity and decreased cooking loss, it often led to increased hardness and chewiness. Algae and their extracts influenced color attributes, with variations based on the algae type. Sensory properties were distinctively affected, generally reducing overall acceptability, although Sea tangle at concentrations of 1–3% showed acceptable scores. Chlorella and Sea tangle positively impacted microbiology during refrigerated storage, while algae and their extracts demonstrated strong antioxidant activity. [ABSTRACT FROM AUTHOR]

Top‐down and bottom‐up factors and their interaction highlight the interdependence of resources and consumer impacts on food webs and ecosystems. Variation in the strength of upwelling‐mediated ecological controls (i.e., light availability and herbivory) between early and late succession stages is less well understood from the standpoint of influencing algal functional group composition. We experimentally tested the effect of light, grazing, and disturbance on rocky intertidal turf‐forming algal communities. Studies were conducted on the South Island of New Zealand at Raramai on the east coast (a persistent downwelling region) and Twelve Mile Beach on the west coast (an intermittent upwelling region). Herbivory, light availability, and algal cover were manipulated and percent cover of major macroalgal functional groups and sessile invertebrates were measured monthly from October 2017 to March 2018. By distinguishing between algal functional groups and including different starting conditions in our design, we found that the mosaic‐like pattern of bare rock intermingled with diverse turf‐forming algae at Twelve Mile Beach was driven by a complex array of species interactions, including grazing, predation, preemptive competition and interference competition, colonization rates, and these interactions were modulated by light availability and other environmental conditions. Raramai results contrasted with those at Twelve Mile Beach in showing stronger effects of grazing and relatively weak effects of other interactions, low colonization rates of invertebrates, and light effects limited to crustose algae. Our study highlights the potential importance of an upwelling‐mediated 3‐way interaction among herbivory, light availability, and preemption in structuring contrasting low rocky intertidal macroalgal communities. [ABSTRACT FROM AUTHOR]

In the context of a circular economy that recommends the most efficient use of wastes, algae wastes have a huge potential for valorization. In this study, algae wastes obtained after the alkaline extraction of active compounds from two types of marine algae (green algae—Ulva sp. and red algae—Callithamnion sp.) were used as biosorbents to remove metal ions from aqueous effluents. The efficiency of these biosorbents was tested for Zn(II), Cu(II), and Co(II) ions, considered technologically valuable metal ions. The batch monocomponent experiments performed under optimal conditions (pH = 5.0; 4.0 g biosorbent/L; 22 ± 1 °C) showed that more than 75% of the metal ions were removed when their initial concentration was less than 1.25 mmol/L. The experimental data were well described by the pseudo-second-order kinetic model and Langmuir isotherm model. The high values obtained for the maximum biosorption capacity (qmax: Cu(II) (0.52 mmol/g) > Zn(II) (0.41 mmol/g) > Co(II) (0.39 mmol/g) for G-AWB, and qmax: Cu(II) (1.78 mmol/g) > Zn(II) (1.72 mmol/g) > Co(II) (1.66 mmol/g) for R-AWB) show the potential use of these biosorbents to remove such technologically valuable metal ions from industrial wastewater. This possibility was tested using industrial wastewater samples obtained from the metal coating industry. The quantitative removal (>91%) of Zn(II), Cu(II), and Co(II) ions was obtained when their initial concentration was adjusted to 50 mg/L. In addition, the rapid and efficient desorption of these metal ions from loaded biosorbents by simple treatment with small volumes of HNO3 (10−1 mol/L) further emphasizes the possibility of their recovery and reuse in the technological circuit. The results included in this study indicate that algae wastes have the potential to be used in industrial effluent decontamination processes and open new perspectives for the implementation of circular economy principles. [ABSTRACT FROM AUTHOR]

Increases in the frequency, intensity and/or diversity of disturbances affecting coral reefs are leading to concerns; some reefs will be overgrown by macroalgae. While numerous studies, particularly in the Pacific, have used macroalgal assays to quantify the rates and agents of herbivory of Sargassum, little is known of the capacity of reef fishes to reduce biomass of Lobophora, a common alga in macroalgal-dominated areas. The aim of this study was to determine the relative palatability of Lobophora to local herbivorous assemblages across two inshore reefs (Havannah Island and Orpheus Island) in the central Great Barrier Reef (GBR), Australia. Multiple choice macroalgal assays were deployed on the reef crest on each reef to determine the relative palatability of three macroalgae taxa: Lobophora, Sargassum and Padina. Additional Lobophora-only assays were deployed on the reef crest at Orpheus Island. Overall, the average reduction in macroalgal biomass was greater at Orpheus Island (25.3 g/3 h, pooled across macroalgae taxa) compared to Havannah Island (5.0 g/3 h), with the reduction in Lobophora biomass (0.3–1.5 g/3 h) being significantly lower than Sargassum (4.7–19.1 g/3 h) at both reefs. The reduction in Lobophora biomass at Orpheus Island was consistently low, whether presented in multiple choice (1.5 g/3 h) or Lobophora-only assays (1.7 g/3 h). Video observations revealed that four species of herbivorous fish (Kyphosis vaigiensis, Naso unicornis, Siganus doliatus, and Siganus canaliculatus) were responsible for the majority of the bites recorded on algae. Despite differences in the relative importance of these four species between islands, all four species took more bites from the Sargassum than Lobophora. The limited susceptibility of adult Lobophora to local herbivorous fish assemblages over short (3 h) temporal scales may play a role in the persistence of Lobophora-dominated areas on inshore reefs of the GBR. Future investigations over longer temporal scales and under different contexts are required to fully assess the susceptibility of Lobophora to herbivores. [ABSTRACT FROM AUTHOR]

Positive interactions among foundation species play a crucial role in achieving and maintaining a good state of the marine environment, enhancing the habitat stability, productivity, and the whole ecosystem functioning. In this regard, macroalgal canopies may affect the biotic and abiotic environmental features, improving the habitat quality for the establishment of other sedentary organisms. In this study, we investigated the effect of intertidal canopy-forming algae on the colonization success of the central-Mediterranean vermetid reef-builder Dendropoma cristatum (Biondi 1859) on artificial substrates produced for reef restoration purposes. An in situ experiment was carried out along the northwestern coast of Sicily during the breeding season of the vermetid snails, by using geopolymer concrete settlement discs with a topographic design to facilitate the vermetid settlement. The discs were placed on the seaward reef rim, underneath the macroalgal canopy, and on adjacent control bare reef areas. The canopy effect on the understory algal colonization and the environmental temperature at the vermetid settlement substrate were also surveyed. After 35 days of field exposure, the vermetid settlement increased by 1.7-fold on the discs underneath the macroalgal canopy compared with that on the bare settlement discs. Moreover, the understory algae showed a higher homogeneity and a lower percent cover on the settlement discs underneath the macroalgal canopy. The peaks of temperature were higher on the bare reef, and the macroalgal canopy also reduced temperature variability under maximum sun irradiance during the diurnal low tides. The vermetid settlement was positively correlated to the canopy cover, which, directly or indirectly, improved the success of colonization of the reef-builder snails on artificial substrates. The deployment of settlement discs where canopy-forming algae are naturally presentmay facilitate the gardening of vermetid clusters that may be translocated to restock the reef-builder density at degraded areas. [ABSTRACT FROM AUTHOR]

The concept of floating algae index (FAI), a measure of the red-edge reflectance of floating vegetation, has been used to map floating macroalgae in global oceans. However, when the algae mats are submerged in water due to winds and other factors, the reduced reflectance (and thus reduced FAI value) is interpreted as being caused by reduced areal density (or biomass density) of algae, leading to underestimated algae amount. Here, a depth invariant FAI is proposed to overcome this difficulty. The depth invariant FAI is formulated using three spectral bands whose selective water attenuations can compensate for the reduced reflectance, resulting in FAI values that are nearly independent of the submerged depth of up to 30 cm with underestimates of the algae amount reduced from >50% to a few percent. In this study, the concept of depth invariant FAI is demonstrated through simulations only. With the new Plankton, Aerosol, Cloud, ocean Ecosystem (PACE) mission and other hyperspectral satellite missions in the near future, such a concept is expected to be tested and evaluated with satellite data, from which the optimal bands can be selected to reduce uncertainties in mapping floating macroalgae. [ABSTRACT FROM AUTHOR]

The potential of seventeen marine seaweed extracts (five Chlorophyceae, six Pheophyceae, six Rhodophyceae) was investigated to determine their antibacterial activity, aiming to evaluate their viability in pharmaceutical applications. The assessment of their bioactivity involved utilizing crude extracts from dried samples against five Gram-positive bacteria, one Gram-negative bacteria, yeast, and fungus using the disk diffusion technique. These samples were collected from Oualidia, situated along Morocco's Atlantic coast. Out of the diverse macroalgae studied, 36% of the extracts exhibited activity against at least one of the tested microorganisms. This outcome strongly supported the notion of leveraging algae extracts as a promising source of antibacterial compounds. In particular, extracts from Cystoseira humilis, Bifurcaria bifurcata and Asparagopsis armata showed zones of inhibition greater than 17 mm. Purification of the compounds responsible for the inhibitory activity against several types of C. humilis microorganisms was performed using chromatography and thin layer chromatography. [ABSTRACT FROM AUTHOR]

Phycocolloids are gelling polysaccharides extracted from algae that have found applications as microbiological culture media, food thickener, and cosmetic rheological modifiers. The extensive use of algae species that have not yet been domesticated has led to overexploitation or supply shortages. Thus, extending the library of phycocolloids would permit to support the industrial changes toward renewable polymer feedstocks but if the source of algae is limited to wild algae species, this may raise issue on the scalability and hinder the creation of a reliable supply chain. In this study, a new phycocolloid extracted from Chaetomorpha aerea, a green seaweed that can be cultivated in open ponds, is identified. Through elucidation of its chemical structure, a gelation mechanism for an extracted sulfated polysaccharide fraction that form stable, transparent hydrogels that can be used for microbiological culture, is proposed [ABSTRACT FROM AUTHOR]

Seaweeds, also known as edible marine algae, are an abundant source of phytosterols, carotenoids, and polysaccharides, among other bioactive substances. Studies conducted in the past few decades have demonstrated that substances derived from seaweed may be able to pass through the blood–brain barrier and act as neuroprotectants. According to preliminary clinical research, seaweed may also help prevent or lessen the symptoms of cerebrovascular illnesses by reducing mental fatigue, preventing endothelial damage to the vascular wall of brain vessels, and regulating internal pressure. They have the ability to control neurotransmitter levels, lessen neuroinflammation, lessen oxidative stress, and prevent the development of amyloid plaques. This review aims to understand the application potential of marine algae and their influence on brain development, highlighting the nutritional value of this "superfood" and providing current knowledge on the molecular mechanisms in the brain associated with their dietary introduction. [ABSTRACT FROM AUTHOR]

Ongoing taxonomic studies of Australian marine algae have led to the recognition of a new species of the green algal genus Rhipilia , here named R. psammophila Huisman & Verbruggen. The new species is unusual for this typically tropical genus in growing in the colder temperate waters of southern Australia and can be distinguished from its congeners by the morphology of its laterally adhering siphons, in addition to unique molecular sequences (rbc L and tuf A). In molecular analysis, the new species is sister to the southern Australian Chlorodesmis baculifera , which is here transferred to Rhipilia and represents the third species in the genus with laterally unattached, free siphons, a feature that previously would have excluded it from the genus. Lateral gametangia are described for R. psammophila and represent the first record of reproduction in Rhipilia. A species of green algae, Rhipilia psammophila, growing in south-western Australia. Taxonomic studies of Australian seaweeds are showing a wealth of undiscovered species. In this paper, a new species of green seaweed, Rhipilia psammophila , is described for specimens from south-western Australia, and a closely related species currently known as Chlorodesmis baculifera is transferred to Rhipilia. Morphological features are proving unreliable in distinguishing genera in this group and molecular analyses are essential. (Photograph by John Huisman.) [ABSTRACT FROM AUTHOR]

As fossil fuel is depleted day by day, there is a vast gap in the market and supply of fuel to the different industries that consume oil. In order to improve fuel properties, performance, combustion, and emissions from diesel engines, microalgae oil biodiesels are used as fuel with 20% of diesel on a mass basis by volume and 50 and 100 ppm of CeO2 nanoparticles as additives in combinations of biodiesel/diesel blends. The engine configuration consists of a single-cylinder, four-stroke, 3.5 kW, 1500 rpm diesel engine. Experiments were performed at constant speed on experimental test fuels for various load conditions. The addition of cerium oxide (CeO2) in the added biodiesel diesel blends improved the brake thermal performance (45%) compared to engine output. With CeO2 in the B20 blends, better combustion properties were observed, such as increased length of combustion (36 CA°), ignition delay (16 CA°), and heat release rate (55 J/deg) in the cylinder. The enhanced and improved fuel characteristics and combustion characteristics of CeO2 in the added biodiesel diesel blends minimise HC (0.54 g/kWh) and CO (4.6 g/kWh) emissions and smoke (0.61%) while increasing NOx (10.2 g/kWh) emissions from the engine cylinder. [ABSTRACT FROM AUTHOR]

Strombus tricornis is a true conch among Strombidae species predominately exploited for feeding and jewelry production. Intensive conch culture targets higher growth rates using convenient formulated feed under suitable conditions. Moreover, the efficacy of the digestive system mainly depends on the nutritive value of aqua feed. Currently, nutriment scientists attempt to use marine algae as an alternative protein for aquatic feed. Hence, an assessment was made to compare the inclusion of seaweed and protein sources in Strombus tricornis diet using five experimental diets (D). D1, D2 and D3 integrated with racemosa, J. rubens, and D. ciliolate, respectively, while D4 and D5 incorporated with animal and plant protein, respectively. Each diet was run into three replicates of conchs in 60 liters of aquaria at 30-32°C for three months. The final body weight of Strombus conchs simultaneous with histomorphology characteristics of the digestive system and muscles were evaluated for five treatments. Results ensured that seaweed enhanced growth for further increased final body weight. Histomorphological results exhibited normal intestinal epithelium of columnar cells and well-studiated muscle fibers when compared with those of control and commercial diets. In conclusion, algae act as a proper alternative feed for protein sources of Strombus. [ABSTRACT FROM AUTHOR]

Ulva prolifera and Sargassum are two common floating macroalgae in China's coastal algal bloom events. Ulva prolifera frequently emerges concomitantly with Sargassum outbreaks, thereby presenting challenges to the monitoring of algal blooms, thereby presenting challenges to the monitoring of algae. To tackle the challenge of differentiating between Ulva prolifera and Sargassum, this study employs Sentinel-2 MSI data for spectral analysis. Notably, significant disparities in the Remote Top of Atmosphere Reflectance (Rtoa) between Ulva prolifera and Sargassum are observed. This study proposes a random forest-based algorithm for discriminating between Ulva prolifera and Sargassum in the regions of the Yellow Sea and East China Sea. The algorithm introduced in this study attains remarkable accuracy in distinguishing Ulva prolifera and Sargassum within Sentinel-2 MSI data, achieving identical F1 scores of 99.1% for both. Moreover, when tested with GF-1 WFV data, the algorithm showcases outstanding performance; this demonstrates the algorithm's robustness and its ability to mitigate the uncertainty linked to threshold selection. Simultaneously, a comparative analysis of algae distribution was conducted for both 2017 and the period from January to May 2023. Experimental results indicate that the algorithm exhibits high accuracy in distinguishing between Ulva prolifera and Sargassum. This capability will significantly enhance the monitoring of large algae in maritime regions; this holds crucial theoretical significance and offers substantial practical value in the realm of marine ecological conservation. [ABSTRACT FROM AUTHOR]

Macroalgae, or seaweed, has a long history of use in human diets, especially in Eastern nations. However, the present interest in these species is driven by their remarkable bioactive and nutritional qualities and their significant availability and underutilization, making them incredibly alluring to people following alternative dietary patterns like vegetarianism and veganism. Sargassum muticum, also known as Japanese wireweed or Asian seaweed, is considered edible and has been consumed in some cultures, popular as a soup ingredient in Korea. This brown macroalgae found in marine environments has been introduced in various regions outside its native range, including Europe and North America. Moreover, this species could be helpful in feeding animals or as soil fertilizer. In this study, the nutritional properties of this marine macroalga were investigated. Nutritional parameters such as protein, sugar, and fiber content were analyzed using classical techniques. In addition, its proximate composition was also determined in terms of moisture, fixed and volatile carbon, and ash content using thermogravimetry, and their major minerals, including calcium, potassium, and magnesium, was determined using the ICP-OS technique. In terms of its mineral content, it was found to have a high mineral content (21% of ash), which consisted mainly of calcium (9 g/kg dw), potassium (77 g/kg dw), and magnesium (12 g/kg dw). In addition, this study determined the presence of iodine using ICP-MS, and 106 mg/kg dw of this essential element was quantified in these algae. The results of this study highlighted the potential nutritional benefits of the tested marine algae. Their composition revealed significant concentrations of vital elements, making them highly advantageous for human/animal dietary requirements with possible health benefits. [ABSTRACT FROM AUTHOR]

This experiment was carried out in the greenhouse of Al-Adawi area of the Damascus Governorate, and labs of the Horticulture Department, Faculty of Agriculture, Damascus University during the period 2020-2021, to study the effect of biofertilizer, Em1 (0, 4, 8 ml/l), and seaweed extract, Alga 600 (0, 1, 2 g/l) and their interactions on growth and productivity of strawberry plant cv. Festival. data were calculated after six months of culture. The combination treatment of Em1, (8 ml/l) and Alga 600 (2 g/l) resulted in the best morphological parameters (23,93 cm, 27.87, 138.81 cm² for plant height, leaf number, and area respectively), physiological parameters (10.30 %, 60.00 mg/100 gm wet weight, 0.59 % for total soluble solids, vitamin C and titratable acidity respectively), and productivity parameters (20.07, 16.4, 250.72 g/ plant for flowers and fruits number/plant and plant yield respectively). The lowest values, however, were obtained in control non-treated plants. [ABSTRACT FROM AUTHOR]

In 2004, Thalassiosira pseudonana was the first eukaryotic marine alga to have its genome sequenced. Since then, this species has quickly emerged as a valuable model species for investigating the molecular underpinnings of essentially all aspects of diatom life, particularly bio‐morphogenesis of the cell wall. An important prerequisite for the model status of T. pseudonana is the ongoing development of increasingly precise tools to study the function of gene networks and their encoded proteins in vivo. Here, we briefly review the current toolbox for genetic manipulation, highlight specific examples of its application in studying diatom metabolism, and provide a peek into the role of diatoms in the emerging field of silica biotechnology. [ABSTRACT FROM AUTHOR]

Marine algae are becoming an important source of valuable candidates of functional food that remain unexplored. Compositional analysis showed that marine algae contain essential nutrients, such as carbohydrates, proteins, fats, and minerals, of which polysaccharides are the main bioactive component. Depending on the source, marine algae polysaccharides are sulfated, which have diverse structures and compositions that influence their biological activities. A growing body of evidence has demonstrated that sulfated polysaccharides derived from marine algae (SPs) exhibit various bioactivities, especially immunomodulation. This review aims at summarizing the structural characteristics of SPs, their immunomodulatory effects, and the structural-immunomodulatory activity relationships between them from articles in recent decade, in order to provide a theoretical basis for the further applications of SPs as promising food or feed additives and possible health products to modulate the immune response. [ABSTRACT FROM AUTHOR]

Trait‐based ecology (TBE) has proven useful in the terrestrial realm and beyond for collapsing ecological complexity into traits that can be compared and generalized across species and scales. However, TBE for marine macroalgae is still in its infancy, motivating research to build the foundation of macroalgal TBE by leveraging lessons learned from other systems.Our objectives were to evaluate the utility of mean trait values (MTVs) across species, to explore the potential for intraspecific trait variability, and to identify macroalgal ecological strategies by clustering species with similar traits and testing for bivariate relationships between traits. To accomplish this, we measured thallus toughness, a trait associated with resistance to herbivory, and tensile strength, a trait associated with resistance to physical disturbance, in eight tropical macroalgal species across up to seven sites where they were found around Moorea, French Polynesia.We found interspecific trait variation generally exceeded intraspecific variation across species. Furthermore, MTV within species varied across sites, suggesting future research should focus on whether these traits are influenced by site‐specific differences in biotic and abiotic drivers. Species grouped into three clusters representing different ecological strategies: species that were defended against herbivores but not strong, species that were strong but not defended and species that were neither. Intraspecific standardized major axis regressions revealed five species exhibited significant or marginally significant positive relationships between these two traits, suggesting trait syndromes within species. Only one species exhibited a significant intraspecific trade‐off, as indicated by a negative regression slope.Synthesis. Our results point to three key takeaways that should provide a foundation to rapidly advance development of TBE for macroalgae in the future. First, our evidence supports the use of MTVs for macroalgae. Second, we identified significant spatial variability in macroalgal traits that may indicate an ability to respond to shifting environmental drivers. Third, measuring even a few traits can be a powerful tool to identify different ecological strategies to resist disturbances such as herbivory and removal by wave action. We hope these novel findings motivate future research into a wider suite of macroalgal traits, functions and strategies to further develop trait‐based approaches for marine macroalgae. [ABSTRACT FROM AUTHOR]

Ulva rigida green seaweed is an abundant biomass consisting of polysaccharides and protein mixtures and a potential bioresource for bioplastic food packaging. This research prepared and characterized novel biodegradable films from Ulva rigida extracts. The water-soluble fraction of Ulva rigida was extracted and prepared into bioplastic films. 1H nuclear magnetic resonance indicated the presence of rhamnose, glucuronic and sulfate polysaccharides, while major amino acid components determined via high-performance liquid chromatography (HPLC) were aspartic acid, glutamic acid, alanine and glycine. Seaweed extracts were formulated with glycerol and triethyl citrate (20% and 30%) and prepared into films. Ulva rigida films showed non-homogeneous microstructures, as determined via scanning electron microscopy, due to immiscible crystalline component mixtures. X-ray diffraction also indicated modified crystalline morphology due to different plasticizers, while infrared spectra suggested interaction between plasticizers and Ulva rigida polymers via hydrogen bonding. The addition of glycerol decreased the glass transition temperature of the films from −36 °C for control films to −62 °C for films with 30% glycerol, indicating better plasticization. Water vapor and oxygen permeability were retained at up to 20% plasticizer content, and further addition of plasticizers increased the water permeability up to 6.5 g·mm/m2·day·KPa, while oxygen permeability decreased below 20 mL·mm/m2·day·atm when blending plasticizers at 30%. Adding glycerol efficiently improved tensile stress and strain by up to 4- and 3-fold, respectively. Glycerol-plasticized Ulva rigida extract films were produced as novel bio-based materials that supported sustainable food packaging. [ABSTRACT FROM AUTHOR]

Ulva rigida C. Agardh (sea lettuce) is a marine green alga. It grows naturally near shorelines in areas with freshwater influence. It can also be cultivated easily on farms and can be developed into many healthy food products, which bring in revenue for Thailand. It is important to develop an effective way to cultivate the alga. In this research, the molecular biology of sea lettuce using the tufA gene for the identification of Ulva genus and morphological characters at different culturing periods of U. rigida thallus were investigated using a light microscope (LM), a scanning electron microscope (SEM) and a transmission electron microscope (TEM). The results revealed that the U. rigida alga consisted of various cell shapes including elliptic, irregular triangle, irregular quadrilateral, pentagonal and polygonal. The cell size increased with increasing periods of culture. However, when the alga was cultured for 28 days, the cell sizes were smaller than the original cells due to cell division during aging, resulting in an increase in cell numbers. U. rigida had grown rapidly in 14 days which was a relatively short period of cultivation. The results of this study indicate that U. rigida has a potential to be scaled up in pilot and commercial scales. [ABSTRACT FROM AUTHOR]