Search Results (1,008)

The Pacific oyster (Crassostrea gigas) is well known for its pronounced umami taste. Here the interaction between the T1R1/T1R3 taste receptor and three oyster-based peptides, namely, FLNQDEEAR (FR-9), EEFLK (EK-5), and FNKEE (FE-5), was investigated via molecular docking and molecular dynamics (MD) simulations, as well as molecular mechanics Poisson–Boltzmann surface area (MM–PBSA) and residue–residue contact score (RRCS) analyses. A full-length human T1R1/T1R3 heterodimer was constructed with AlphaFold3. MD simulations indicated that the binding of FR-9 led to a large structural fluctuation, a large radius of gyration, and a large solvent accessible surface; on the contrary, FE-5 yielded the most stable receptor–ligand complex. The MM-PBSA analysis showed that the binding free energies of the three peptides were in the order of FR-9 > EK-5 > FE-5. The RRCS analysis indicated that RRCS values per residue were in the order of FR-9 < EK-5 < FE-5, in line with the reported umami score, and that the highest taste score of FE-5 originated from the hydrophobic interactions between Glu301 (receptor) and Phe1 (ligand) as well as the salt bridges between arginine (Arg277 and Arg307, receptor) and glutamic acid (Glu4 and Glu5, ligand) residues. These findings show that structural stability and residue contact density were more informative than binding affinity for distinguishing the taste intensity of umami peptides. Full article

Oyster health is important for aquaculture productivity and sustainability. In Thailand, the white scar oyster, Crassostrea belcheri, is being promoted for cultivation, yet its health status has not been compared between research breeding and community farming sites. This study evaluated histopathological features, ultrastructure, apoptosis, and defender against apoptotic death 1 (dad1) gene expression in sexually mature C. belcheri collected from these two sites. Gill tissues were examined by histology, transmission electron microscopy, TUNEL assay, and gene expression analysis, while organ condition was assessed using a Health Assessment Index (HAI). The proportion of TUNEL-positive cells in the gills and mantle differed significantly between sites (p < 0.05), with higher levels in oysters from the farming site. In contrast, TUNEL-positive cells in the digestive gland did not differ significantly between sites, although brown cells were observed only in the digestive gland of oysters from the breeding site, suggesting possible physiological stress. To assess the expression level of dad1 in oysters cultured under different conditions, RT-qPCR revealed no significant difference between the two sites. The breeding site also had lower temperature and salinity than the farming site. Overall, these findings suggest that site-specific environmental conditions may influence gill health and stress-related responses in C. belcheri, providing baseline information for oyster health assessment and aquaculture management. Full article

Conventional sterilization methods limit smallholder mushroom cultivation in PNG. This study evaluated alternative disinfection approaches for Pleurotus ostreatus (P. ostreatus) using coffee parchment and Cenchrus fungiraminus (C. fungigraminus) as substrates. After screening 20 strains, the superior strain PXF9 was selected. Three methods were compared: (1) Complete Sterilization with Aseptic Inoculation (CSAI) applied to T1 (experimental) and T2 (sawdust control); (2) Short Sterilization with Open Inoculation (SSOI) applied to T3 (experimental) and T5 (control); and (3) Non sterilization with Open Inoculation (NSOI) applied to T4 (experimental). CSAI (T1) achieved the highest yield (3985.26 ± 2.00 ^d g/24 bags), biological efficiency (83.03%), protein (28.44 g/100 g), and profit (14.76 USD), with the fastest colonization (21 days). SSOI (T3) produced the largest fruiting bodies; NSOI (T4) had the lowest heavy metal levels. SSOI and NSOI were economically beneficial (9.88 and 5.96 UDS per 24 bags). Bioactive compounds (e.g., naringenin, ergosterol peroxide), were detected across treatments. While CSAI maximizes productivity, SSOI and NSOI offer low-cost alternatives for resource-limited farmers. Full article

Ergosterol (ERG) is a bioactive sterol found in fungal cell membranes with reported cholesterol-lowering, antioxidant, and antitumor properties. Supercritical Fluid Extraction (SFE) conditions were optimized for Lentinula edodes (shiitake) using Response Surface Methodology and subsequently applied to Pleurotus ostreatus (oyster). Optimized SFE (690 bar, 69.8 °C, no co-solvent) produced significantly more concentrated ERG extracts than Soxhlet extraction for both species—280.57 ± 10.80 mg_ERG/g_extract for shiitake and 95.87 ± 7.18 mg_ERG/g_extract for oyster—corresponding to a 107% and 65% increase, respectively. Three biomass pre-treatments—ultrasound, microwave, and enzymatic—were evaluated in combination with SFE. Enzymatic pre-treatment with chitinase significantly improved ERG concentration: 337.53 ± 23.12 mg_ERG/g_extract for shiitake. These results obtained after analysis of samples by GC-MS demonstrate that high-pressure SFE combined with chitinase pre-treatment is an effective strategy for producing ERG-rich extracts from fungal matrices. Full article

Microplastics constitute an emerging contaminant of major concern in Latin America, where human exposure predominantly occurs through ingestion of drinking water and marine/estuarine food chains. This review synthesises available evidence on occurrence, exposure pathways, toxicological mechanisms, and regional public health risks, while examining regulatory and monitoring limitations that constrain effective risk management. Reported concentrations in drinking water show a wide range (1–1194 particles/L), dominated by PET, PP, and PS, with fibres and fragments as the main morphotypes. In commercial marine species, prevalence reaches 70–100%, with burdens up to 44 particles/g in oysters and ~90 particles/250 g in mussels. Estimated Daily Intake is 2–5 times higher in children (e.g., Chile: 13.03 vs. 5.59 particles/day in adults). Toxicological mechanisms include oxidative stress, chronic inflammation (NF-κB pathway), endocrine disruption, intestinal dysbiosis, systemic translocation, and placental transfer, exacerbated by vectorization of local co-contaminants (Hg from mining, Cd/Pb from agriculture). Risk indices indicate extreme danger in Brazil, Chile, and Ecuador, where data are available. Significant geographic and methodological gaps persist, with Brazil dominating research (~50–60%). Multicenter biomonitoring, harmonised surveillance networks, and SDG-aligned policies are urgently needed to reduce exposure burdens, protect vulnerable populations, and advance toward comprehensive regional risk assessment. Full article

Selenium-enriched yeast is an important organic selenium source for improving the nutritional value and physiological function of aquatic products. However, whether ploidy affects the molecular responses of Pacific oysters (Crassostrea gigas) under selenium supplementation conditions remains unclear. In this study, diploid, triploid, and tetraploid Pacific oysters were fed a selenium-enriched diet for 10 days. Hepatopancreas tissues were collected for antioxidant enzyme assays and transcriptomic analysis. The results showed that triploid oysters exhibited higher superoxide dismutase, glutathione peroxidase, and catalase activities, together with a relatively lower malondialdehyde level, suggesting stronger antioxidant defense under selenium supplementation conditions. Transcriptomic analysis revealed substantial numbers of differentially expressed genes across all groups compared, indicating pronounced ploidy-dependent transcriptional responses. Functional enrichment analysis showed that these genes were mainly associated with metabolic processes, oxidative stress responses, membrane components, endocrine-related pathways, lipid metabolism, and signal transduction. Several redox-related genes, including glutathione S-transferase family genes, CHAC1, superoxide dismutase family genes, and NRX1, showed ploidy-dependent expression patterns. In particular, triploid oysters appeared to rely more on enzymatic antioxidant defense and glutathione turnover, whereas tetraploid oysters showed a stronger tendency toward redox signal integration and homeostatic regulation. These findings provide new insights into ploidy-dependent selenium responses in Pacific oysters and offer a theoretical basis for the development and utilization of selenium-enriched oyster products. Full article

To optimize the shape stability of 3D-printed white calcium sulfoaluminate (WCSA) cement composites, oyster shell powder (OSP) and cuttlebone powder (CBP) were introduced as white admixtures to regulate rheological properties and printability. The setting behavior, rheological properties, and shape stability of the WCSA cement composites were evaluated by Vicat setting-time tests, rotational rheological measurements, three-stage thixotropic recovery tests, and structural deformation measurements, together with mechanical strength tests, XRD, and SEM analyses. The results showed that the incorporation of OSP and CBP shortened the setting time of WCSA cement composites. The initial and final setting times decreased from 41 min and 67 min to 17 min and 30 min in the WCSA cement composites with OSP, and from 42 min and 66 min to 20 min and 33 min in the WCSA cement composites with CBP, which improved printing operability. As the OSP and CBP content increases from 0% to 24%, the dynamic yield stress of WCSA cement composites increased from 48.83 Pa to 530.59 Pa and 60.30 Pa to 1085.80 Pa, respectively. The thixotropic recovery degree of WCSA cement composites increased from 57.89% to 86.46%, and 56.60% to 92.14%, respectively. As the OSP and CBP contents increase from 0% to 24%, the structural deformation decreased from 12.39% to 6.91% and 13.29% to 5.12% respectively, which improved buildability of the printed structures. In addition, although OSP and CBP reduced the mechanical strength of WCSA cement composites compared with the control group, the flexural and compressive strengths gradually recovered as the contents increased from 6% to 24% due to the enhanced filling effect and improved particle packing. This study provides a reference for the application of marine calcareous solid wastes in sustainable 3D-printed cementitious materials. Full article

As an important aquaculture bivalve, the Pacific oyster (Crassostrea gigas) undergoes a metamorphosis process during its embryonic development. The mortality rate of the eye-spot larva during the metamorphosis and settlement stage is relatively high, which urgently needs to be solved. Glutathione (GSH), as a key antioxidant and immune regulator in organisms, plays an important role in the growth, development, and immune defense of marine invertebrates. Analysis of oyster transcriptome data revealed that the expression of key enzyme-producing GSH, Glutathione S-transferase Kappa 1, reached the highest level at the pediveliger larvae (the stage just before eye-spot larvae), suggesting its important role in the larval settlement process. This study investigated the effects of reduced glutathione supplementation in pediveliger larvae on the settlement metamorphosis and immune capacity of eye-spot larvae. The results showed that high concentrations of glutathione (100 μmol/L, 500 μmol/L) significantly reduced the larval eye-spot rate and settlement rate, with larvae in the 500 μmol/L group nearly all dead after 48 h. Meanwhile, low-concentration GSH (7 μmol/L) could significantly increase the settlement rate of larvae, which was 1.17 times (p < 0.05) that of the control group. When the larvae developed to 1-month-old eye-spot larvae, the survival rate of larvae in the low GSH group significantly increased (38.42 ± 15.98%) after Vibrio splendidus stimulation, while they were almost all dead in the control group. Low GSH could also significantly increase lysozyme LZM activity (by 1.39 times, p < 0.05) and Cu/Zn-SOD activity (by 1.15 times, p < 0.05). Gene expression analysis found that low GSH promoted expressions of larval settlement and metamorphosis-related genes, including ecdysone receptor, P450, and calmodulin. Treatment with low GSH also enhanced the expressions of immune genes of SOD, CAT, and LZM. In summary, a low glutathione supplement can promote the settlement process of oyster eye-spot larvae and enhance disease resistance. These findings reveal the role of glutathione in the metamorphosis and settlement of oyster larvae, providing a scientific basis for optimizing techniques for oyster seedling cultivation. Full article

Precision microclimate management is critical for stabilizing oyster mushroom (P. ostreatus) production under variable farm conditions. This study evaluates Mushroom Kothi, an IoT-enabled cultivation system integrating low-cost sensors, automated control strategies, and cloud-based monitoring, across multiple agro-climatic zones and seasons in India (Bharat). Comparative trials with conventional farmer-managed systems show that Mushroom Kothi significantly reduces microclimate variability, improves yield consistency, enhances fruit body uniformity, and increases water-use efficiency without relying on energy-intensive cooling. The results demonstrate that biologically informed, automated environmental stabilization—rather than growth forcing—can support sustainable, smallholder-oriented precision mushroom cultivation. Full article

Tidal flats are shrinking and eroding due to sea-level rise and human activities. Ecological submerged breakwaters (ESBs) offer a novel solution combining coastal protection and ecological restoration, but their effects on sediment dynamics lack field evidence. This study presents synchronous in situ measurements from an inner tidal flat (WN01) and an outer shallow area (WN02) of a newly built riprap slope-type ESB on the northern coast of the Sheyang River Estuary, Jiangsu, China. Using Acoustic Doppler Velocimeters (ADVs) and wave-tide gauges, we examined hydrodynamics, suspended sediment concentration (SSC), bed shear stress, erosion–accretion, and sediment transport under normal-weather and strong wave events. Within the constraints of a 14-day observation at two stations, our results indicate that: (1) The ESB reduced wave height and weakened currents, shifting dominant bed shear stress from wave-dominated outside to tide-dominated inside. Under normal weather, both sides were accretive. (2) Strong wave events caused sharp increases in bed shear stress, net erosion on both sides, and a 2–3-fold SSC rise, breaking the normal balance. (3) Suspended sediment transport direction remained northwest inside during strong wave events but shifted to northeast/southeast outside, demonstrating effective isolation of wave-driven anomalies. Bedload was trapped inside, resulting in no net sediment loss, in contrast to the unprotected southern tidal flat. (4) We recommend moderately lowering the ESB crest elevation to prevent excessive accretion and implementing “grey-green” restoration (salt marshes or oyster reefs) to enhance coastal resilience against sea-level rise. Full article

Lignocellulosic agricultural residues are abundant yet underutilized despite their potential for sustainable bioconversion. This study evaluated spent mushroom substrate (SMS) from Pleurotus ostreatus cultivation and roots of leafy vegetables (RLV) as alternative substrates for Pleurotus production, using wheat straw as a control. Two species, P. ostreatus and P. citrinopileatus, were cultivated on different SMS/RLV ratios and the immunomodulatory potential of harvested mushrooms was assessed. Specifically, protein (PE-D-P3 < 3 kDa) and carbohydrate (CE-D) fractions obtained after in vitro digestion were applied to LPS-challenged THP-1 cells and immune-related gene expression was analyzed by qPCR. Both species significantly modulated immune responses. The PE-D-P3 showed a more pronounced immunomodulatory effect, significantly downregulating IL1B, IL6 and TNF, whereas the CE-D reduced only TNF expression. Substrate composition influenced bioactivity: PE-D-P3 from SMS 80-RLV 20% resulted in the greatest reduction in IL1B, IL6 and TNF, while CE-D from SMS 60-RLV 40% reduced IL1B and CXCL8. These findings provide insights that both fungal species and substrate composition influence immunomodulatory compound production. Valorizing lignocellulosic residues through optimized mushroom cultivation represents a sustainable strategy for producing functional ingredients with applications in human and animal health, particularly for preventing inflammation-related disorders. Full article

This study provides the first comprehensive assessment of microplastic (MP) contamination within oyster bed ecosystems of the Kingdom of Bahrain. Sediment, water, and oyster samples were collected from six sites representing diverse environmental conditions. Raman spectroscopy identified the presence of 12 distinct polymer types, with polypropylene (PP), polyurethane (PU), poly(ethylene terephthalate)/diamine/multi-walled carbon nanotube (PET/diamine/MWCNT), and fluorinated ethylene propylene (FEP) being the most prevalent. MPs occurred predominantly as fragments, films, and pellets, with black being the most common color across all matrices. MP abundances ranged from 750 to 1850 MPs/kg dry weight in sediments, 2100–9600 MPs/L in water, and 1.78–5.25 MPs/individual in oysters, with particles (<50 µm) most frequent in oyster tissues. Although spatial variation was evident across regions, detected polymers included types associated with known ecotoxicological risks. No significant correlation was observed between sediment grain size and MP abundance, suggesting that additional hydrodynamic or anthropogenic factors may influence MP distribution. Overall, this study provides critical baseline data on MP contamination in Bahrain’s marine environments and highlights the need for continued monitoring to assess potential risks to marine ecosystems and seafood safety. It also contributes to the limited understanding of MPs in the Arabian Gulf, informing future monitoring, conservation and policy initiatives that support long-term environmental sustainability. Full article

Growing concern over antibiotic resistance in poultry production has increased interest in natural feed additives such as Pleurotus ostreatus (oyster mushroom)-derived products. This study evaluated three freeze-dried oyster mushroom powders: total fresh fruiting body (OMP-TF), cooked solid residue (OMP-CSR), and cooked liquid fraction (OMP-CL), as dietary supplements in male Coturnix japonica. A β-glucan positive control and basal diet negative control were included. Birds (1-day-old) were fed experimental diets from 1 to 28 days. An Escherichia coli lipopolysaccharide (LPS) challenge was applied 12 h before sampling to induce an immune system activity. Growth performance, immune system activity, spleen relative weight, ileum morphometry, and antioxidant capacity were then evaluated to determine the effects of the experimental diets. Mushroom supplementation significantly modulated body weight during weeks 2–3 and overall weight gain, with OMP-TF maintaining higher body weight at week 4. Relative spleen weight, villus morphometry, cytokine responses (IL-1β, IL-2, IL-4), and total antioxidant capacity were not significantly altered compared with LPS controls. Overall, P. ostreatus supplementation modulated growth performance under inflammatory challenge conditions, without significantly affecting the measured immune or intestinal parameters. These findings suggest a potential role of mushroom-derived products as growth-supporting feed additives; however, further studies are needed to clarify their effects on immune function and intestinal health. Full article

In Luoyuan Bay, China, Sporobolus alterniflorus invasion has hindered mangrove restoration and disrupted faunal communities within mangrove habitats. This study investigated its impact on mollusk, crab, and fish assemblages across mangrove, mudflat, and invaded habitats from 2019 to 2020. Results showed that species diversity of three assemblages did not differ significantly between invaded and non-invaded mangrove habitats; however, assemblage structure was altered and functional traits declined markedly in invaded areas. Compared with non-invaded mangroves, invaded habitats showed decreases of 81.6% in mollusk density, 50.7% in mollusk biomass, 66.6% in crab density and 84.2% in crab biomass. Dominant fish species (Acanthogobius ommaturus, Liza carinata, Stolephorus chinensis) also exhibited lower body size, total size and biomass in invaded habitats. Given the close dependence of coastal residents on these faunal resources, a socioeconomic analysis of livelihood strategies was conducted, revealing Sinonovacula constricta aquaculture achieved the highest net income-to-investment ratio, 122.7% higher than nearshore fishery and 308.3% higher than shallow-sea oyster cultivation, while professional shellfish farming yielded the highest net income per hectare, 23.6% higher than oyster cultivation. Thus, both forms of shellfish aquaculture provide greater economic returns than other livelihood options. Based on these findings and niche theory, we propose a management framework: after removing S. alterniflorus, plant native mangroves (Kandelia obovata) in mid-to-high intertidal zones and lease lower flats for shellfish farming. This framework has the potential to integrate ecological restoration with local livelihoods and may inform similar efforts in other regions facing biological invasions and restoration challenges. Full article

The physiological performance of the Pacific oyster Magallana gigas in subtropical lagoon systems is shaped by the interaction between environmental variability, reproductive dynamics, and oxidative stress. This study quantified monthly changes in the growth and proximate composition of oysters cultivated in Estero La Cruz, Sonora, and evaluated their relationship with temperature and chlorophyll-a as proxies for thermal stress and trophic availability. Shell growth was continuous, while somatic biomass increased markedly during winter, indicating high thermal tolerance and metabolic flexibility. Proximate composition showed pronounced seasonal oscillations, with energy reserves accumulating during periods of high primary productivity and declining sharply in December, coinciding with peak gametogenic activity. Antioxidant enzyme activities (SOD, CAT, GPx) increased toward winter, reflecting elevated oxidative stress. Correlation and regression analyses revealed consistent relationships among environmental variables and biological responses, identifying temperature as the main factor associated with growth variability. Overall, these results demonstrate a strong coupling between environmental forcing, energy allocation, and oxidative stress, providing an integrative framework for understanding oyster performance and supporting aquaculture management in subtropical coastal systems. Full article