Search Results (6,211)

Background: Chlorella, a unicellular green alga, is currently one of the most popular algae supplements due to its high content of bioactive compounds. Chlorella’s wide range of macro- and micronutrients, including chlorophyll compounds and carotenoids, has been suggested to influence various disorders related to the digestive and nervous systems. This review’s primary purpose was to critically analyze the effects of Chlorella intake on gut microbiota and brain function. Methods: The authors conducted a systematic review with narrative synthesis of peer-reviewed articles written in English and published in PubMed, Web of Science, and Scopus spanning the years 2009 to 2026 (PROSPERO registration number CRD42024527705). The search protocol was performed following PRISMA guidelines. Primary outcomes encompassed physiological variables, such as gut microbial composition, short-chain fatty acids, brain-derived neurotrophic factor, and hippocampal cell density. Secondary outcomes were assessed through neurobehavioral tests and psychological questionnaires. Results: Out of the 1333 articles identified, 47 studies were deemed eligible, and 21 met the predefined criteria, subsequently incorporated into this systematic review. In total, 10 articles documented interventions involving Chlorella and their effects on the gut microbiota, whereas 11 articles investigated several variables pertinent to brain function. Most of the studies included were conducted in animal models, with only a limited number of human trials. Nineteen studies (90%), predominantly preclinical, reported positive associations between Chlorella consumption, gut microbiota modulation, and physiological or neurobehavioral markers related to the gut–brain axis. Conclusions: Chlorella consumption may modulate gut microbiota composition and function, potentially influencing brain-related processes. However, the available literature lacks studies simultaneously addressing both gut microbiota and brain health parameters limiting the understanding of the underlying physiological mechanisms. Full article

Marine invertebrates, such as sponges, corals, mollusks and sea squirts, are appropriate climate-change descriptors on sublittoral rocks. The present study assesses the diversity, relative abundance and health condition of epibenthic invertebrates inhabiting sublittoral rocky habitats within the Natura 2000 network (Chalkidiki, north Aegean), after the 2021 marine heatwaves. Samplings were made with non-destructive techniques in autumn 2021 by diving along vertical belt transects (up to 30 m). Fourteen stations were surveyed, revealing 56 macroscopic invertebrates, 16 algae and 15 reef-associated fishes. Richness showed increased values at the deepest and steepest cliffs. Reefs were the dominant habitat type, hosting different facies of infralittoral algae and coralligenous biocenoses. Three algal (Halimeda tuna, Peyssonelia squamaria, Lithophyllum strictiforme) and 12 invertebrate (Aplysina aerophoba, Chondrilla nucula, Chondrosia reniformis, Ircinia variabilis, I. oros, Sarcotragus foetidus, Spongia officinalis, Balanophyllia europaea, Cladocora caespitosa, Pinna nobilis, Spondylus gaederopus, Microcosmus sabatieri) species were found in partial or full necrosis. According to relevant data collected about 20 years ago, the biota had higher diversity without signs of necrosis. Sarcotragus foetidus, I. variabilis, B. europaea, C. caespitosa and S. gaederopus were the most affected by necrosis species over the surveyed area. They represent appropriate climate change descriptors to assess the resilience of Mediterranean MPAs, being priority species in marine conservation. Full article

1-Deoxy-D-xylulose-5-phosphate synthase (DXS) serves as the initial rate-limiting enzyme in the methylerythritol phosphate (MEP) pathway, governing the biosynthesis of precursors for photosynthetic pigments and terpenoids. In this study, the LaDXS2-2 gene was cloned and functionally characterized in lavender (Lavandula angustifolia). The full-length coding sequence (CDS) of LaDXS2-2 spans 2178 base pairs, encoding a protein of 725 amino acids. Phylogenetic analysis revealed that LaDXS2-2 is most closely related to the DXS from Salvia miltiorrhiza. Expression profiling demonstrated that LaDXS2-2 was highly expressed in flower buds, and its transcript levels were significantly upregulated (p < 0.05) in response to ethephon, high light intensity, and low temperature, while exhibiting tissue-specific responses to gibberellin application. Subcellular localization assays confirmed LaDXS2-2 is targeted to the chloroplast. Heterologous overexpression of LaDXS2-2 in tobacco resulted in a marked increase in photosynthetic pigment content, enhanced the actual photochemical efficiency of photosystem II [Y(II)], and reduced non-photochemical quenching (NPQ). Integrated transcriptomic and metabolomic analyses further revealed that LaDXS2-2 overexpression activated the diterpenoid biosynthesis pathway and upregulated amino acid metabolism as well as the TCA cycle, while competitively suppressing phenylpropanoid and flavonoid biosynthesis pathways. These findings indicate that LaDXS2-2 not only enhances photosynthetic efficiency by promoting the synthesis of photosynthetic pigments but also suggests a potential role in influencing primary carbon and nitrogen metabolism, as inferred from transcriptomic and metabolomic data. This functionality may ultimately influence plant growth and metabolic homeostasis. Overall, this study provides a theoretical foundation for the synergistic improvement of photosynthetic efficiency and secondary metabolism in crops. Full article

Certain sacoglossan sea slugs, often known as “solar-powered sea slugs”, are a group of marine gastropods that have the unique ability to photosynthesize by stealing functional chloroplasts from algae. The sacoglossan Elysia papillosa can maintain functional chloroplasts for up to two weeks after feeding. The microbiome of these slugs may play a crucial role in their metabolism, immunity, development, but more importantly their photosynthesis. Shotgun metagenomic sequencing was conducted on four samples of E. papillosa in order to characterize their microbiome. Sequences were classified and relative abundance was quantified with Centrifuger and functional data was examined using SqueezeMeta. Bacteria were analyzed by taxonomic groups and hypothesized function to the sea slug was determined with literature analysis. All samples were dominated by phyla Actinomycetota, Bacillota, Patescibacteriota, and Pseudomonadota. The presence of the phyla Bacteroidota and Bacillota was notable in all samples, which contain species known to produce enzymes that break down polysaccharides. It is possible that these bacteria could assist in degradation of the polysaccharide xylan found in the cell walls of Penicillus, the algal food source of E. papillosa. One species that was found in all samples was Cutibacterium acnes which has been shown to be an important component of the gut microbiota in other marine invertebrates and may provide the host with vitamin B12 and other beneficial nutrients. Many of these bacteria may be opportunistic rather than commensal. As a result, more research is required to describe the interactions between the slug and its microbiome, but this preliminary report provides a valuable starting point for identifying the microbiome make-up to further understanding of these relationships. Full article

Tropical coastal waters are increasingly recognized as critical reservoirs for virulent, antibiotic-resistant enteric pathogens, yet seasonal dynamics governing their spatial distribution remain poorly characterized. We hypothesized that hydrological shifts and anthropogenic nutrient enrichment drive the seasonal distribution, virulence profiles, and antimicrobial resistance (AMR) of Escherichia coli, Salmonella spp., and Shigella spp. in the Jaffna Peninsula, Sri Lanka. Across 25 coastal sites during dry and transitional seasons, we integrated physicochemical water quality assessment, culture-based enumeration, PCR-based virulence gene profiling, Minimum Inhibitory Concentration (MIC) assays, GIS mapping, and statistical analyses. Key water quality parameters, including ammonium, nitrite, and total phosphorus, showed significant seasonal variation (p < 0.05), reflecting distinct hydrological regimes across seasons. A total of 220 E. coli, 200 Salmonella spp., and 100 Shigella spp. isolates were examined for virulence gene profiles and antibiotic tolerance. E. coli was detected at 80–88% of sites, Salmonella spp. at 72–88%, and Shigella spp. at 32–48%. Among E. coli isolates, stx1 was detected at 20–28% of sites and eae at 16% across both seasons. The stn gene was detected in Salmonella spp. at 12–28% of sites seasonally. Virulence profiling confirmed STEC harbouring stx1, stx2, and eae; Salmonella spp. carried stn; and Shigella spp. possessed invasion-associated genes. Trimethoprim–sulfamethoxazole resistance was recorded in 63.2% of E. coli, 33.0% of Salmonella spp., and 31.0% of Shigella spp. isolates at the lowest tested concentration of 4 µg/mL., while ciprofloxacin and piperacillin–tazobactam retained greater efficacy. Correlation analyses revealed significant associations among faecal contamination, nutrient enrichment, and virulence gene prevalence, implicating untreated sewage discharge and eutrophication as likely ecological factors associated with pathogen occurrence. These findings designate the Jaffna coastal zone as a significant reservoir of virulent AMR enteric pathogens, underscoring the urgent need for integrated One Health surveillance and seasonally adaptive coastal water quality management. Full article

Organophosphate esters (OPEs) are ubiquitous in the global water environment and may pose potential risks to aquatic ecosystems and human health. Herein, we present a simple and efficient method for accurate quantification of nineteen OPEs in water based on automated liquid–liquid extraction (LLE) with dichloromethane and hexane, followed by gas chromatography–tandem mass spectrometry (GC-MS/MS) with isotope dilution calibration. This method demonstrated a negligible matrix effect, satisfactory recoveries (70–120%), and low limits of detection (0.46–2.32 ng/L). A total of 3, 9, 10, and 11 OPEs were detected in Wahaha pure water, tap water, river water, and seawater, respectively, with total OPE (∑OPE) concentration ranges of 8.23–18.5 ng/L, 159–218 ng/L, 202–623 ng/L, and 111–175 ng/L, respectively. Among the detected OPEs, tris(2-chloroethyl) phosphate (TCEP) and tris(1-chloro-2-propyl) phosphate (TCIPP) were the predominant compounds in four test water matrices. The risk quotient (RQ) results revealed that OPEs exhibited a low risk to algae, crustaceans and fish in the river water of Zhoushan and seawater of Sanmen Bay. Overall, the proposed method is sensitive and reliable for routine OPE analysis in drinking and environmental waters. Full article

Reservoirs in karst regions exhibit significant carbon sink potential; however, how different reservoir types influence carbon sequestration remains poorly understood. In this study, dual carbon isotopes (δ¹³C–Δ¹⁴C) were applied to trace dissolved organic carbon (DOC) sources in an open reservoir (Aha Reservoir, AHR) and a closed reservoir (Guanshan Lake, GSL) in southwestern China, and to evaluate their carbon sequestration potential. DOC concentrations in GSL were significantly higher than those in AHR (4.14 ± 0.28 mg/L > 3.37 ± 0.30 mg/L) (p < 0.01), along with lower δ¹³C values (−30.34 ± 0.51‰ < −28.18 ± 0.31‰) and more enriched Δ¹⁴C values (−6.94 ± 11.07‰ > −93.74 ± 6.76‰). The δ¹³C–Δ¹⁴C tracing revealed that plants were the primary DOC source for AHR (61 ± 2%), whereas algae dominated DOC sources in GSL (70 ± 2%). Inflow rivers and water retention time (WRT) likely drive differences in DOC sources and concentrations between the two reservoirs. The absence of inflow rivers and the longer WRT in GSL created favorable conditions for algal growth, resulting in substantially higher chlorophyll a (Chl.a) concentrations (103.00 ± 29.87 μg/L > 13.10 ± 3.29 μg/L) and enhanced production of autochthonous DOC through a stronger biological carbon pump (BCP) effect. These conditions further facilitate the formation and accumulation of recalcitrant DOC (RDOC), ultimately increasing DOC concentrations in GSL. Our findings highlight that closed karst reservoirs may represent important yet underappreciated carbon sinks and should receive greater attention in future carbon-sink assessments. Full article

The mosquito-associated virome may modulate host biology and influence vector competence, highlighting the importance of understanding its composition. Here, a metagenomic analysis was conducted to characterize the virome of the sea-rock pool mosquito Aedes mariae across sexes and developmental stages, together with water from its sea-rock pool breeding site in San Felice Circeo (Italy). A total of 51 viral taxa were identified, including viruses associated with bacteria and archaea (39%), plants, algae, fungi, and protists (35%), vertebrates (8%), and invertebrates (18%), including insect-specific viruses such as Mesoniviridae, Baculoviridae, Nudiviridae, Iridoviridae and Totiviridae. Twenty-five percent of the taxa were shared across samples, suggesting acquisition from breeding-site water and persistence across stages during development. Interestingly, the need for host genome filtering highlights the potential sequence similarity between viral and mosquito genomes, which may reflect the presence of endogenous viral elements or historical virus–host interactions. These findings represent the first characterization of the virome of Aedes mariae and highlight the role of aquatic breeding sites in shaping mosquito virome. Finally, we argue the importance of adequate sequencing depth and host genome filtering to capture the diversity of the mosquito virome. Full article

Heavy metals such as copper and zinc serve as essential trace elements for photosynthetic organisms at appropriate concentrations. However, at elevated levels, these metals (along with non-essential metals like chromium, lead, mercury, and cadmium) exert severe toxic effects on aquatic life. Heavy metal toxicity primarily relates to oxidative damage in living systems through a direct increase in reactive oxygen species (ROS) and reduction in cellular antioxidant capacity. Previous research on algae of different types with different coverings led us to complete the comparative framework. For this purpose and to assess biotechnological potential, we investigated chromium effects on Euglena gracilis, which possesses a unique pellicle covering, to determine whether it could serve as a chromium biosensor or bioremediation agent. Using Raman spectroscopy and absorption microspectrophotometry (MSP), we found that chromium concentrations of up to 500 μM had no effect on Euglena chlorophyll or carotenoid profiles, consistent with the pellicle preventing chromium entry and protecting the photosynthetic apparatus. However, concentrations > 10 μM severely inhibited growth through extracellular interference with essential nutrient utilization (ammonium phosphate and vitamin B₁₂). Growth inhibition was reversible upon transfer to fresh medium, confirming that cellular machinery remained intact. These results suggest that E. gracilis cannot serve as a chromium biosensor (photosynthetic apparatus unaffected) or bioremediation agent (no chromium internalization), but its ability to maintain photosynthetic functionality in chromium-contaminated environments suggests the potential for alternative applications in polluted water biomass production. Full article

Improving tenderness in whole-muscle pork products remains a technological challenge, particularly when natural processing strategies are preferred over conventional additives, as texture is regarded as one of the most important quality attributes influencing consumer perception and acceptance of meat products. This study investigated whether two plant proteases, papain and bromelain, incorporated into a red algae-based brine containing Palmaria palmata could enhance the quality of injected pork loin without compromising microbiological safety or sensory acceptance. Seven batches were produced: a control sample and six enzyme-treated samples containing papain or bromelain at 0.015%, 0.030%, and 0.045%. Overall, the enzymatic treatments had a limited effect on proximate composition. However, a modest decrease in fat content was observed, from 3.09% in the control sample to 2.70–2.82% in the samples treated with the highest concentrations of papain and bromelain (0.045%). In contrast, instrumental color and texture were strongly affected. Enzyme-treated samples became lighter, less red, and less saturated, with redness decreasing from 13.07 in the control to 5.19–6.66 in the highest-dose treatments and total color differences reaching 8.66. The most relevant effect was observed in texture, where papain and bromelain markedly reduced shear force, shear work, hardness, gumminess, and chewiness; shear force decreased from 26.22 N/cm² in the control to 10.78 N/cm² and 9.38 N/cm² in the batches treated with the highest enzyme concentrations. During refrigerated storage, total viable counts increased gradually but remained low, with a maximum of 4.56 × 10² CFU/g, while Escherichia coli, Salmonella spp., and Listeria monocytogenes were not detected. Sensory analysis further showed that enzymatic treatment improved perceived tenderness and juiciness without reducing overall acceptability. These findings indicate that papain and bromelain can be used as natural tenderizing tools in injected pork loin, offering a promising route toward cleaner-label meat products with improved texture and preserved microbiological quality. Full article

The algae-based landfill leachate (LL) treatment system has been proved promising for nutrient recycling and biomass production at lab- or small-scale photobioreactors (PBRs). However, many assessment tools such as techno-economic analyses (TEAs) usually utilize parameters from small-scale experiments as input data to predict the potential performance of commercial large-scale or full-scale bioreactors. Reliability of using data from lab-scale for commercial large-scale estimation is still uncertain. This study compared the performance of three photobioreactor systems that differed simultaneously in scale, geometry, light intensity, mixing mode, and aeration: 0.125 L small-scale flask, 1 L medium-scale tubular PBR, and 15 L wall-shaped PBR for real LL treatment. The 1 L medium-scale tubular photobioreactor outperformed the other two systems in biomass growth rate and the rates of nitrogen and phosphorus removal, even though all three systems removed nearly all NH₄-N and PO₄-P (≈100%) within two weeks. Possible reasons for this better performance include stronger illumination, a bubbling aeration mode, the reactor shape (which improves mixing), and higher surface area to volume ratio × light intensity. According to these results, using relatively small-scale flask experimental data for predictive analysis of industrial-scale algal systems could be inadequate. In this study, volumetric optical radiation (VOR) serves as a promising preliminary descriptive indicator to reflect the overall performance of an algal-based treatment system. Full article

Rivers have always been essential to humankind. They are used for many purposes and, as a result, have been heavily modified. Human impacts, many of them still poorly understood, interfere with river ecosystems, making them vulnerable to disturbances. Amongst these, mega events along riverbanks are listed. We studied the effects of the “FM4 Frequency Festival,” which attracted more than 200,000 visitors, on microalgae in the channelized section of the River Traisen in St. Pölten, the capital of Lower Austria. During the festival, phosphorus, dissolved organic carbon, and chloride increased significantly during the whole study period compared with before and after. Although the overall epilithic biomass remained unchanged during the festival period, the phytobenthos community experienced an increase in taxonomic richness downstream of the festival area. Both the Shannon diversity (mean ± SD = 2.89 ± 0.34) and Pielou’s evenness (mean ± SD = 0.73 ± 0.08) did not differ significantly between the sampling dates before, during, and after the festival. We found a shift towards Achnanthidium minutissimum as the dominant species during the festival. Diatoma ehrenbergii, which is sensitive to nutrient enrichment and organic pollution, disappeared during the event. Overall, the biofilm shifted towards a community dominated by heterotrophs during the festival, likely due to high organic loading. Pelagic microalgae experienced a rise in the total taxa number during the festival, which was partly caused by resuspension of phytobenthos. Our results reflect significant impacts from visitors to the Traisen ecosystem. Not only short-term changes in the hydrochemical environment but also mechanical disturbances of the phytobenthos caused by visitors were demonstrated. We suggest continuous monitoring to verify that such events will not have long-term impacts on the system. Full article

Rapid Atlantification is altering primary productivity and benthic-pelagic coupling in the Eurasian Arctic. This study assessed sedimentary pigments as indicators of exported production in the poorly studied St. Anna Trough, a critical conduit between the Barents and Kara seas. Sediment samples were collected at 20 stations in autumn 2023, and phytopigment concentrations were analyzed spectrophotometrically alongside hydrological data. Multivariate analysis revealed two distinct benthic regimes separated by the Marginal Ice Frontal Zone. The southern sector, influenced by thick seasonal warm water masses (WWM) in the subsurface layer, exhibited mesotrophic conditions with mean chlorophyll-a + pheophytin-a concentrations of 30.28 ± 6.51 µg g⁻¹. The northern sector, dominated by Arctic-origin water masses, was oligotrophic (4.45 ± 0.54 µg g⁻¹). Redundancy analysis identified WWM thickness as the primary driver, explaining 60.5% of the total variance in pigment contents, followed by ice-cover duration (9.8% negative effect). Pigment indices and high pheophytin proportions indicated predominantly detrital organic matter, though stations near the Barents Sea inflow showed fresher material. The prevalence of chlorophyll-b in the north suggested ice-associated green algae, while chlorophyll-c dominated the diatom-rich southern inflow. These findings establish a crucial baseline for monitoring climate-driven shifts in pelagic-benthic coupling as sea ice retreat continues. Full article

Biological soil crusts (BSCs) play key roles in arid, semi-arid regions and ecological marginal habitats. This study focused on four types of sand-fixing plantations established in 1990 in alpine sandy land (Salix psammophila, SL; Caragana korshinskii, NT; Salix cheilophila, WL; Populus simonii, XYY). Soil samples were collected from bare sand, algae crusts, and moss crusts. Soil particle size distribution, physicochemical properties, and enzyme activity were determined. Then bacterial communities were analyzed using high-throughput (Illumina) sequencing and the correlations among these three factors were examined. The results showed that: (1) From bare sand to algae and moss crusts, the content of fine particles (clay + silt) gradually increased. (2) Soil water content (SWC), nutrients and enzyme activities increased progressively. (3) In the study area, the dominant bacterial phyla of BSCs included Pseudomonadota, Cyanobacteria, Actinobacteriota and Vibrionota. Principal Coordinates Analysis (PCoA) and Analysis of Similarities (ANOSIM) results showed that BSCs drive the differentiation of bacterial communities during succession, while forest stands influence their spatial distribution. (4) Spearman’s correlation and redundancy analysis (RDA) showed that available phosphorus (AP), alkaline hydrolyzable nitrogen (AN), soil organic matter (SOM), catalase (CAT), pH, soil water content (SWC), and alkaline phosphatase (ALP) are key physicochemical factors shaping the bacterial community structure of BSCs. Mantel’s test confirmed that these variables mediated BSCs’ bacterial community structure. This study elucidates the mechanisms underlying ecological restoration via BSCs and provides a theoretical basis for future restoration efforts in alpine sandy land. Full article

Non-indigenous or alien macroalgae are increasingly recognized as ecological threats, sources of raw material, and reservoirs of bioactive compounds for industry and agriculture. This review analyses the valorization potential of this biomass, focusing on their antifungal and elicitor activities against phytopathogenic fungi, particularly Mediterranean (De Bary) Whetzel, 1945. The literature published since 2020 was retrieved from Scopus using targeted keyword combinations. Three major topics were examined: (i) invasive and beach-cast macroalgal and their ecological context, (ii) antifungal and elicitor properties of macroalgal extracts, and (iii) the use of deep eutectic solvents (DES) for the green extraction of bioactive compounds. Species such as Asparagopsis armata, Rugulopteryx okamurae, and Sargassum muticum have shown promising antifungal and elicitor effects, frequently associated with phenolic compounds and polysaccharides. Extracts from these algae can inhibit the growth of fungi or activate plant defense pathways, providing environmentally friendly alternatives to synthetic pesticides. Moreover, DES and natural DES (NADES) offer tunable, biodegradable solvents capable of efficiently extracting these bioactive molecules while reducing the environmental impact associated with conventional organic solvents. Overall, the valorization of this biomass represents a sustainable strategy that simultaneously mitigates ecological and economic impacts and contributes to the development of sustainable inputs in agriculture. Full article