Search Results (268)

Maintaining sustainable production of healthy and nutritious food represents a major global challenge. Cultivated meat could reduce the environmental impact of livestock production, but it remains costly, largely due to the expense of fetal bovine serum, a common cell culture media supplement. Algal and cyanobacterial proteins, particularly phycobiliproteins, represent promising sustainable sources of potentially bioactive peptides that may contribute to the development of serum-reduced or serum-free culture media. This study investigated the potential of hydrolysates prepared using the protein extracts of the red alga Porphyra haitanensis and the cyanobacterium Arthrospira platensis as functional supplements for cell cultivation in a low-serum environment. Twelve hydrolysates were generated by treating protein extracts from Arthrospira platensis and Porphyra haitanensis with six proteolytic enzymes: pepsin, trypsin, chymotrypsin, subtilisin, thermolysin and proteinase K. The effects of these hydrolysates were studied in three cell models of mammalian (CHO-K1), avian (QM7), and fish (MACK1) origin. The effects of hydrolysates on cell viability, proliferation, and antioxidant activity were evaluated. A. platensis–chymotrypsin hydrolysate significantly improved QM7 cell viability compared to control in both 80% reduced-serum and tryptose phosphate broth conditions (p ≤ 0.0001). Additionally, peptide composition analysis and identification of amino acid sequences provided preliminary insights into potentially bioactive chromopeptides associated with the maintenance and promotion of cellular growth. Algae/cyanobacteria-derived hydrolysates positively regulated cell viability and proliferation in serum-reduced conditions, although effects were dependent on the algal species, enzymatic treatment, and cell type. These findings highlight their potential as sustainable supplements for alternative cell culture media. Full article

Frequent marine heatwaves (MHWs) pose significant threats to and have a profound impact on the structure and functioning of marine ecosystems. The response of marine organisms to MHWs may depend on the background temperature of their habitats. Saccharina japonica is a cold-temperate species that is vulnerable to thermal stress. However, it remains unclear how habitat-related temperatures impact responses of S. japonica to MHWs. In this study, the algae were exposed to MHWs (+∆4 °C) under two background temperatures (control level, 8 °C; warmer level, 12 °C), and the growth, photosynthetic performance, and biochemical composition were measured at the end of the MHW and the recovery periods. The results showed that a warmer background temperature increased the growth and pigment contents (Chlorophyll c and fucoxanthin) of S. japonica, but decreased chlorophyll fluorescence parameters, including the effective quantum yield, relative electron transport rate, non-photochemical quenching, and photochemical quenching. The MHWs had no significant effect on growth rate, photosynthetic performance, or biochemical compositions at the background temperature of 8 °C. In contrast, MHWs reduced growth and biochemical composition contents (Chlorophyll a, Chlorophyll c, fucoxanthin and soluble protein) at a warmer level, but the negative influence was alleviated after the recovery period. Furthermore, there was a considerable increase in the total antioxidative capacity caused by MHWs under warmer conditions. Overall, the stimulation in growth demonstrated that warmer conditions (12 °C) may provide a better growth temperature for young S. japonica but also increase the risks of biomass losses and physiological damage triggered by MHWs. These findings deepen our understandings of the tolerance and resistance of S. japonica to heatwaves and provide useful information for managing and modulating the cultivation of this important commercial seaweed. Full article

The objective of the present study was to evaluate the impact of high-density polyethylene (HDPE) used in two particle sizes (40 and 125 µm) on selected biochemical parameters in two species of green algae: Chlorella vulgaris and Scenedesmus quadricauda. Exposure to microplastics resulted in decreased cell numbers (up to 43%) and reductions in protein (up to 42%), monosaccharide, and chlorophyll contents in both algal species. Oxidative stress, as reflected by increased hydrogen peroxide levels (up to 120%) and enhanced lipid peroxidation, was observed in HDPE-treated cells. This was accompanied by elevated antioxidant enzyme activity, changes in ascorbate and proline content, and alterations in carotenoid composition. Thus, toxicity of HDPE and the induction of defense mechanisms involved in adaptation to environmental pollutants were confirmed in both microalgae. Changes in the physicochemical properties of the tested polymer surface were investigated using Fourier-Transform Infrared Spectroscopy, scanning electron microscopy (SEM), and porosimetry analysis. The presence of biofilm, hydroxyl groups, higher total pore volume, and maximum pore width on the surface of the microplastic confirmed that green algae may be responsible for the first step in HDPE structure modifications. Understanding the interactions between such micropollutants and green algae, key primary producers in aquatic food webs, is therefore essential. Full article

Brown algae are important primary producers in coastal ecosystems, where they provide habitat and food for numerous marine species. For humans, they provide raw materials (food, animal feed, and ingredients for pharmaceuticals and cosmetics) as well as ecosystem services such as coastal protection and carbon sequestration. The molecular characterization of brown algae is necessary to understand their role in ecosystems, their biochemical resources, and responses to environmental stresses—knowledge that is crucial for the sustainable use and biotechnological applications of seaweed. Within this context, we analyzed more than 300 primary and secondary metabolites by gas chromatography–mass spectrometry to elucidate the metabolic profiles of seven habitat-forming species of brown algae in the arctic and temperate seas. Metabolite profiles were discussed considering physiological and ecological characteristics of the different algae, thus revealing the taxon-specific biochemical signatures and metabolite patterns contributing to seaweed adaptation to their typical habitats. Three important groups of metabolites representing polyols, phenolic compounds, and organic acids, were analyzed and discussed in more detail. Our study revealed metabolic diversity of species from the same order and genus, thereby indicating a very distinct regulation at the molecular level to meet metabolic needs of the habitat. The knowledge of different compositions of algal extracts can be used to develop specialized applications for humans in cosmetic, medical, or nutritional sectors. Full article

Sustainable water remediation requires catalytic strategies that remove contaminants efficiently while reducing chemical input, byproduct formation, and ecological disturbance. Conventional radical-dominated advanced oxidation processes can rapidly degrade pollutants, but their reliance on high oxidant dosages and freely diffusing reactive oxygen species often causes matrix quenching, non-selective oxidation, low oxidant utilization, and potential ecological risks. Mild interfacial catalysis provides a materials-chemistry strategy to regulate oxidative intensity and direct contaminant transformation under environmentally relevant conditions. In this review, mild catalysts are defined by pathway-selective, interfacially confined, and environmentally compatible oxidation rather than by low dosage alone. Representative non-radical or low-intensity pathways, including singlet oxygen generation, surface-mediated electron transfer, high-valent metal–oxo species, and direct oxidative transfer processes, are discussed in relation to active-site structure, oxidant utilization, matrix tolerance, and byproduct control. We further summarize how coordination environments, defect chemistry, heteroatom configurations, nanoconfinement, and immobilized interfaces regulate reactive-species formation and interfacial charge transfer. Key material platforms, including single-atom catalysts, heteroatom-doped carbons, defect-engineered oxides, catalytic membranes, hydrogels, and floating or immobilized composites, are evaluated from mechanistic and application-oriented perspectives. Finally, catalyst regeneration, cost, microbial community responses, algae–bacteria balance, ecotoxicity, and long-term safety are discussed to guide sustainable aquatic ecosystem restoration. Full article

Background: Oil spills have dramatically increased, causing significant damage and pollution to marine ecosystems. The entry of petroleum hydrocarbons into the ocean may lead to the occurrence of harmful algal blooms (HABs). The amino acid changes in harmful algae after oil spills remain unclear. Methods: In order to study the effect of oil spills on the amino acid mechanism of typical causative species, the composition and relative abundance of amino acids in Heterosigma akashiwo were investigated under different water accommodated fractions (WAFs) of 180# fuel oil. Results: Random forest prediction of polycyclic aromatic hydrocarbon toxicity to microalgae identified pyrene, benzo[k]fluoranthene, and fluoranthene as significant contributors. A total of 16 species of amino acids were detected in Heterosigma akashiwo, among which alanine, proline, aspartic acid, cysteine, lysine, and histidine were the predominant ones. As the concentration of the WAF increased, alanine abundance decreased significantly, indicating that the WAF disrupted the metabolic balance of alanine, with the degree of interference being positively correlated with exposure concentration. With the increase in culture time, the abundance of cysteine increased at 1%, 3%, and 5% WAFs, whereas the cysteine increased and then decreased at 7% and 10% WAFs. The abundance of aspartic acid and lysine showed no obvious pattern with culture time under WAF stress. Significant increases in the abundance of proline and histidine were observed in the WAF treatments. Conclusions: This study investigated the impact of oil spill pressure on the amino acid content of harmful algae, providing a scientific basis for understanding the potential impact of oil spills on the occurrence of HABs. Full article

To scientifically evaluate the health of river aquatic ecosystems in the Qianxinan Buyi and Miao Autonomous Prefecture, southwestern Guizhou, systematic surveys of benthic macroinvertebrate and periphytic algal communities were conducted in representative rivers during October 2024 (autumn) and April 2025 (spring), coupled with concurrent water quality monitoring. Reference sites were selected based on water quality indicators and habitat conditions. Core parameters were identified through correlation analysis, discriminatory ability analysis, and distribution range analysis to construct a Benthic Index of Biotic Integrity (B-IBI) and a Periphytic Algae Index of Biotic Integrity (P-IBI) suitable for the region. These indices were then applied to assess the ecological health of the rivers. Additionally, stepwise regression analysis was employed to investigate the key environmental drivers influencing the two biotic integrity indices. The results indicated that: (1) In terms of species composition, the benthic macroinvertebrate community structure was relatively simple, dominated by arthropods, particularly chironomid larvae. Bacillariophyta and Cyanophyta consistently dominated the periphytic algae community. (2) Assessments using both B-IBI and P-IBI showed that the overall river health in spring was slightly better than in autumn. However, more than half of the sampling sites were rated as “fair” or worse in both seasons. The reference sites (S2, S10) consistently exhibited “excellent” or “good” health, while the impaired sites showed significant spatial heterogeneity. Discrepancies between B-IBI and P-IBI ratings at some sites revealed differential responses of the two biological communities to environmental stressors. (3) Stepwise regression analysis unveiled a seasonal shift in key environmental drivers. The primary factor affecting the B-IBI in autumn was biochemical oxygen demand (BOD₅), which shifted to total phosphorus (TP) and ammonia nitrogen (NH₄⁺-N) in spring. For the P-IBI, the main factor changed from dissolved oxygen (DO) in autumn to chemical oxygen demand (COD) in spring. These findings confirm the applicability of the B-IBI and P-IBI systems in this region, and indicate that multi-assemblage integrated assessments can contribute to understanding the health status of river ecosystems in the Qianxinan Prefecture. This study could serve as a scientific reference for the protection, management, and restoration of local river ecosystems. Full article

The plastisphere can have a significant impact on the buoyancy, toxicity, and functionality of microplastics (MPs). Little is known about plastisphere structure, especially in salt-impacted lakes, despite the growing focus on the salinization of lakes. Virgin polypropylene and polyethylene terephthalate MPs were incubated for two weeks in flow-through containers in the epilimnion (low phosphorus, low salinity, high light) or hypolimnion (high P, high salinity, and low light) of a salt-impacted lake and then incubated in the lab in either their original water or water from the alternate depth to determine plastisphere response should the lake fully turn over. Environmental factors, including phosphorus concentration, light level, salinity level, and temperature, rather than polymer type, influenced community composition. Bacterial communities on MPs in the epilimnion exhibited higher diversity compared to those in the hypolimnion. Algal communities on MPs showed a similar trend, with greater diversity in the epilimnion. Overall, initial community composition had a stronger influence on community structure (priority effect) than the environment in which the plastisphere was grown. For those plastisphere communities capable of responding to species-specific desirable environmental conditions, lake mixing that results in increases in phosphorus and salinity from the hypolimnion to the epilimnion will increase the abundance of algae on MPs in the photic zone. Full article

The present study provides an exhaustive exploration of twelve macroalgal species from the Adriatic Sea, including seven brown algae (Ericaria amentacea, Fucus virsoides, Cutleria multifida, Cystoseira compressa, Cystoseira corniculata, Gongolaria barbata and Padina pavonica), three green algae (Codium adhaerens, Codium vermilara and Ulva lactuca), and two red algae (Scinaia furcellata and Asparagopsis taxiformis). Matrix solid-phase dispersion (MSPD) was applied as the extraction technique, using generally recognized as safe (GRAS) solvents. The bioactive profile of the extracts was assessed through the quantification of total phenolic content (TPC) and antioxidant activity. Among the three phyla, U. lactuca, F. virsoides and S. furcellata exhibited the highest TPC (0.8, 26 and 3.0 mgGAE·g⁻¹) and antioxidant activity (1.9, 38 and 7.5 mgTE·g⁻¹), respectively. Targeted HPLC-MS/MS analysis enabled the identification of nineteen phenolic compounds across all taxa. Chlorophyta showed a characteristic profile enriched in coumarins, benzaldehydes and flavanones, including the selective detection of 7-hydroxycoumarin in species with higher antioxidant potential. Additionally, compounds such as chlorogenic, rosmarinic and caffeic acids exhibited taxon-specific distributions that may explain differences in antioxidant activity. Complementary untargeted ultra-high performance liquid chromatography quadrupole time-of-flight (UHPLC-QToF) metabolomics analysis provided broader coverage, revealing eighty metabolites spanning phenolics, sugars, organic acids, lipids, amino acids and their derivatives. Notably, the proposed detection of fatty acid esters of hydroxy fatty acids (FAHFAs) represents the first report of these compounds in macroalgae, alongside a pronounced presence of sulphated phenolics. Overall, these findings provide a robust baseline on the bioactivity and chemical composition of Adriatic macroalgae, highlighting their value as a natural source of functional compounds. Full article

A comparative analysis of the long-term dynamics of phytobenthos on the Black Sea coast from 1964 to 2020 has been conducted. The aim of the work was to assess changes in species composition, quantittive characteristics, and distribution of bottom vegetation under the influence of natural and anthropogenic factors. The research was carried out at three transects using standard hydrobotanical methods and analysis of climatic data. The results revealed significant structural reorganization of the communities: a decrease in the proportion of key brown algae (Ericaria crinita and Gongolaria barbata) by the middle of the observation period with partial recovery by 2020, an overall increase in biomass and species diversity, and increased role of epiphytes and green algae. An expansion of the depth range of the phytal zone and an increase in the presence of the deep-water species Phyllophora crispa were established. The main drivers of the transformation are increased anthropogenic pressure and climate change, which aligns with global trends. The obtained data are important for developing measures to preserve coastal ecosystems and can be used in monitoring the ecological state of the aquatic area. A promising direction for further research is the quantitative assessment of the role of the macrophytobenthos in this area in carbon sequestration. Full article

Macroalgae are increasingly recognised as promising sources of bioactive compounds with nutritional and functional relevance. This study investigated the biochemical composition of selected green, brown, and red marine macroalgae from the Mediterranean coast sampled at different seasons, focusing on fatty acid profiles, carotenoid composition, phenolic and flavonoid contents, antioxidant activity, and multivariate biochemical structuring. Fatty acid distributions were determined by Gas Chromatography (GC)-Flame Ionisation detector (FID), carotenoids were quantified and profiled by Liquid Chromatography–Mass Spectrometry (LC-MS), and total phenolic content, total flavonoid content, and antioxidant capacity (ABTS^•+ and DPPH^• methods) were assessed using standard spectrophotometric assays. Principal component analysis was applied to evaluate relationships among biochemical variables and taxonomic patterns. Brown macroalgae tended to exhibit more complex and enriched biochemical profiles, containing high proportions of long-chain n-3 polyunsaturated fatty acids, particularly eicosapentaenoic acid, elevated total carotenoid contents dominated by fucoxanthin, the highest total phenolic and flavonoid contents, and antioxidant activities. Green macroalgae were characterised by fatty acid profiles rich in saturated and C18 polyunsaturated fatty acids, while carotenoid compositions were dominated by lutein and siphonoxanthin. Red macroalgae exhibited comparatively simpler lipid and pigment patterns, characterised by palmitic acid and zeaxanthin as dominant components and lower total carotenoid levels. Principal component analysis revealed taxonomic structuring, with brown algae clearly separated from green and red groups, while seasonal differences were minor. Antioxidant activity closely clustered with carotenoids and total phenolic content, suggesting their combined contribution to radical-scavenging capacity. Overall, brown species appear as promising candidates for functional foods and nutraceutical applications. Full article

The increasing exploitation of sea cucumbers has driven widespread population declines, highlighting the need to improve knowledge and understanding of the early life history stages of exploited species such as Holothuria tubulosa, one of the most common holothurians along Mediterranean coasts. This study investigated larval settlement success and juvenile early survival of H. tubulosa larvae, considering two algal biofilms as settlement cues: the diatom Amphora sp. and the green alga Ulvella lens. Larvae were reared under controlled hatchery conditions, and, once reaching the doliolaria stage, larvae were individually exposed to biofilm-conditioned substrates vs. a control without biofilm. Settlement dynamics and larval development were monitored over 35 days and analysed using generalised linear mixed models, while the biochemical composition of the biofilms was assessed through protein, carbohydrate, and lipid quantifications. Larvae exposed to algal biofilms successfully settled and metamorphosed, whereas no settlement occurred in the control. U. lens induced the highest settlement success (54%) and supported subsequent juvenile development, while Amphora sp. resulted in lower settlement rates (21%) and higher post-settlement mortality. Although Amphora sp. showed higher protein and carbohydrate content, settlement and survival were enhanced on U. lens, suggesting that biofilm structure and biochemical cues play a primary role in regulating settlement processes. These findings improve the understanding of settlement mechanisms in H. tubulosa and provide valuable insights for hatchery production, conservation strategies, and the sustainable aquaculture of Mediterranean sea cucumbers. Full article

Phycological knowledge in Mexico has primarily focused on intertidal zones, coral reefs, and, to a much lesser extent, mangroves. In mangroves, there are isolated studies on various areas of the country, and in many cases, references are made to the macroalgae that grow in association with them, incidentally as part of floristic inventories for a given area. Therefore, the present study aimed to compile existing information on macroalgae associated with mangrove roots in seven ecoregions throughout Mexico. The search was integrative using Google Scholar, Scopus, and Web of Science with different keywords; only records of algae growing on mangrove roots were considered. The literature review includes information on the composition, species richness, their distribution across Mexican marine ecoregions, and their morphofunctional groups. A systematic literature review from 1972 to 2024 identified 40 studies with data on macroalgae found on mangrove roots. The final phycofloristic inventory recorded 155 taxa, distributed among 67 genera, 39 families, 19 orders, and three phyla. The most representative orders were Ceramiales and Cladophorales, and the families with the greatest number of taxa were Rhodomelaceae and Cladophoraceae. This checklist provides a baseline for future taxonomic and biogeographic studies of mangrove-associated macroalgae. Full article

The reliability of power transmission and distribution depends on the proper functioning of power transformers, which use conventional mineral oil as an insulating fluid. The lower fire class and biodegradability of mineral oil have led to a shift towards second-generation oils from vegetable and plant crops. Ester fluids provide a better performance in combination with solid pressboard/paper insulation, increasing the lifetime of power transformers compared to those using mineral oil. Considering the need for sustainability in the near future, second-generation oils are no longer feasible, and hence, third-generation oils derived from microalgae species are suitable alternative fuels for the energy sector. The fatty acid methyl ester (FAME) content of algae is similar to that of biodiesel, making it a suitable fluid for power transformers. A detailed overview of third-generation feedstock (algae) for power transformer applications is provided, focusing on the extraction of algal oil, in conjunction with safety precautions and its fatty acid content, and a comparison with conventional vegetable and plant-based oils is presented. Various properties of algal oil (fatty acid composition, kinematic viscosity, oxidation stability, breakdown voltage, etc.) are analyzed to assess its suitability as a transformer fluid. This review article comprehensively analyzes the current research landscape surrounding the use of algal oil as an insulating fluid in transformers. It critically evaluates both the potential advantages and the unique challenges associated with this alternative to conventional mineral oil and second-generation vegetable and plant-based oils. Full article

Intraspecific variation in mitogenomes has provided the resolution to distinguish between morphologically indistinguishable species and highlight cryptic speciation. This level of variation is underexplored in introduced marine algae. This study evaluated the mitogenomic variability of Gracilaria vermiculophylla, one of the most invasive red algae in the Northern Hemisphere. Nine mitogenomes, comprising seven newly generated complete mitogenomes from Korea, Japan, and Morocco, plus two publicly available mitogenomes, were included in our analysis. The mitogenomes were highly conserved, ranged from 26,064 to 26,178 bp in length, and contained 52 genes comprising 25 protein-coding genes, three rRNAs, and 24 tRNAs. Nucleotide composition showed a strong AT bias (71.6%), with AT skew and GC skew values of 0.050 and 0.014–0.021, respectively. Pairwise divergences of cox2, rnl and rns rRNA were remarkably low, in a range of 0–0.06%, suggesting alternate markers for determining recent introductions. The phylogenetic relationship based on protein-coding genes revealed three shallow groups in G. vermiculophylla, which were correlated with distribution: two C groups from warm temperate sites and one T group from cold temperate sites. This result highlights mitogenomics as a new tool for the deeper understanding of phylogeography and invasion genetics of marine red algae. Full article