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Two endophytic bacterial strains, designated S1-1-2 T and S1-1-8, were isolated from the leaves of a mangrove plant, Avicennia marina. The isolates were Gram-stain-negative, motile, rod-shaped bacteria with lateral flagella. Growth occurred at 4-41 °C, pH 4.0-11.0, and 0.5-25.0% NaCl. The predominant fatty acids of the novel strains were C18:1 ω6c/ω7c, C19:0 cyclo ω8c, and C16:0. The predominant respiratory quinone was Q-9. The DNA G + C contents of strains S1-1-2 T and S1-1-8 analyzed by genome sequences were 63.8%. Phylogenetic analysis based on 16S rRNA gene sequences obtained using sanger sequencing and whole-genome phylogenetic analysis revealed an affiliation between the two strains and the genus Salinicola in the class Gammaproteobacteria. Detailed genotypic, chemotaxonomic, and phenotypic data support the conclusion that these two strains should be described as a novel species in the genus Salinicola. Here, Salinicola avicenniae sp. nov. (type strain S1-1-2 T = LMG 32655 T = MCCC 1A19027T) is proposed.
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Avicennia , Composición de Base , ADN Bacteriano , Gammaproteobacteria , Filogenia , ARN Ribosómico 16S , Avicennia/microbiología , ARN Ribosómico 16S/genética , China , ADN Bacteriano/genética , Gammaproteobacteria/clasificación , Gammaproteobacteria/genética , Gammaproteobacteria/aislamiento & purificación , Ácidos Grasos/análisis , Técnicas de Tipificación Bacteriana , Análisis de Secuencia de ADN , Hojas de la Planta/microbiología , Endófitos/genética , Endófitos/clasificación , Endófitos/aislamiento & purificaciónRESUMEN
Mangrove forests, a critical coastal ecosystem, face numerous anthropogenic threats, particularly from aquaculture activities. Despite the acknowledged significance of viruses in local and global biogeochemical cycles, there is limited knowledge regarding the community structure, genomic diversity, and ecological roles of viruses in mangrove forests ecosystems, especially regarding their responses to aquaculture. In this study, we identified 17,755 viral operational taxonomic units (vOTUs) from nine sediments viromes across three distinct ecological regions of the mangrove forests ecosystem: mangrove, bare flat, and aquaculture regions. Viral assemblages varied among three regions, and the pathogenic viruses associated with marine animals, such as the white spot syndrome virus (WSSV) from Nimaviridae, were identified in this study. The relative abundance of Nimaviridae in the bare flat region was higher than in other regions. Furthermore, viruses in distinct mangrove forests sediments regions have adapted to their environments by adopting distinct survival strategies and encoding various auxiliary metabolic genes involved in carbon metabolism and antibiotic resistance. These adaptations may have profound impacts on biogeochemical cycles. This study provides the first insights into the effects of vegetation cover and aquaculture on the community structure and ecological roles of viruses in mangrove forests sediments. These findings are crucial for understanding the risks posed by anthropogenic threats to mangrove forests ecosystems and informing effective management strategies.
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Acuicultura , Sedimentos Geológicos , Virus , Sedimentos Geológicos/virología , Virus/genética , Humedales , Animales , Viroma , EcosistemaRESUMEN
Dredging wastewater discharge is a significant environmental concern for mariculture near mangrove ecosystems. However, little attention has been paid to its effects on the soil physical-chemical properties and enzyme activities in mangrove habitats. This study compared the soil physical-chemical properties and enzyme activities in the polluted area that received dredging wastewater from a shrimp pond with those in the control area without wastewater to explore the effects of wastewater discharge on the soil physical-chemical properties and enzyme activities. Variations in soil physical-chemical properties and enzyme activities across different tidal flat areas and depths were also examined. The polluted area exhibited lower soil salinity (10.47 ± 0.58 vs. 15.64 ± 0.54) and moisture content (41.85 ± 1.03 % vs. 45.81 ± 1.06 %) than the control area. Wastewater discharge increased soil enzyme activities, (acid phosphatase, protease, and catalase), resulting in higher inorganic nitrogen (13.20 ± 0.00 µg g-1 vs. 11.60 ± 0.03 µg g-1) but lower total nitrogen (0.93 ± 0.01 mg g-1 vs. 1.62 ± 0.11 mg g-1) in the contaminated zone. From the control to polluted area, there was an approximate increase of 0.43 and 0.83 mg g-1 in soil total phosphorus and soluble phosphate, driven by increased acid phosphatase. However, soil humus and organic matter decreased by 0.04 and 1.22 %, respectively, because of wastewater discharge. The impact of wastewater discharge on the soil physical-chemical properties and enzyme activities was most pronounced in the landward and surface soil layers (0-5 cm). The results showed that wastewater discharge altered soil physical-chemical properties and enzyme activities, accumulating soil bioavailable nutrients (inorganic nitrogen and soluble phosphate), but at the cost of reduced soil quality, especially organic matter, further adversely affecting the overall health of mangrove ecosystems. Prioritizing the management of wastewater discharged from mariculture adjacent to mangrove forests is crucial for mangrove conservation.
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Ecosistema , Suelo , Suelo/química , Aguas Residuales , Estanques , Humedales , Fosfatos , Fosfatasa Ácida , Nitrógeno/análisisRESUMEN
Dredging wastewater (DW) from aquaculture ponds is a major disturbance factor in mangrove management, and its effects on the greenhouse gas (GHG) fluxes from mangrove sediment remain controversial. In this study, we investigated GHG (N2O, CH4, and CO2) fluxes from mangrove sediment at typical aquaculture pond-mangrove sites that were stimulated by DW discharged for different input histories and from different farm types. The GHG fluxes exhibited differing cumulative effects with increasing periods of DW input. The N2O and CH4 fluxes from mangrove sediment that received DW inputs for 17 y increased by â¼10 and â¼1.5 times, respectively, whereas the CO2 flux from mangrove sediment that received DW inputs for 11 y increased by â¼1 time. The effect of DW from shrimp ponds on the N2O flux was significantly larger than those of DW from fish/crab ponds and razor clam ponds. Moreover, the total global warming potentials (GWPs) at the field sites with DW inputs increased by 29-129% of which the CO2 flux was the main contributor to the GWP (85-96%). N2O as a proportion of CO2-equivalent flux increased from 2% to 12%, indicating that N2O was an important contributor to the increase in GWP. Overall, DW increased the GHG fluxes from mangrove sediments, indicating that the contribution of mangroves to climate warming was enhanced under DW input. It also implies that the carbon sequestration potential of mangrove sediments may be threatened to some extent. Therefore, future assessments of the carbon sequestration capacity of mangroves at regional or global scales should consider this phenomenon.
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Braquiuros , Gases de Efecto Invernadero , Animales , Estuarios , Aguas Residuales , Ríos , Dióxido de Carbono/análisis , Monitoreo del Ambiente , Acuicultura , China , Metano/análisis , Óxido Nitroso/análisis , HumedalesRESUMEN
Crabs in mangroves could enhance the transfer of organic carbon (OC) from leaf litter to soils, whose variation with the difference in crab size is, however, not well known. A 32-day laboratory feeding experiment was conducted to explore the effects of different sizes of the crabs Parasesarma plicatum foraging on leaf litter of Kandelia obovata on OC accumulation in mangrove soils. Mean rates of soil OC accumulation due to leaf foraging by large, medium, and small crabs were 21.11, 16.11, and 0.77 mg C ind-1 d-1, corresponding to the rates of OC removal from leaf litter of 62.60%, 51.37%, and 2.19%, respectively. Large and medium crabs ingested larger amounts of leaf litter, and soil OC accumulation rates resulting from leaf foraging by large and medium crabs were approximately 8 times higher than those by leaf litter decomposition and triple those by non-leaf foraging. Small crabs ingested the smallest amount of leaf litter, which was almost used for their growth and metabolism. These results underline the key ecological roles of leaf foraging by crabs, especially those with large and medium sizes, in OC accumulation in mangrove soils, which is conducive to estimating carbon sequestration in mangrove soils.
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Braquiuros , Animales , Carbono/metabolismo , Ecosistema , Suelo , Secuestro de CarbonoRESUMEN
The present study δ13C, δ15N and fatty acid compositions of two dominant mangrove crabs, Tubuca arcuata and Parasesarma plicatum were compared between a mangrove site frequently receiving dredged wastewater from mariculture ponds and an adjacent reference site, to investigate the impact of wastewater discharge on their diets. A laboratory experiment was also conducted to further test how their diets changed with the wastewater input. The result showed no significant change in the δ13C while clear 15N enrichment of crabs in association with the wastewater discharge. Changes in 15N signature and fatty acid composition of the crabs due to the wastewater discharge indicated that the impact of wastewater discharge was related to crab species, being more apparent on the deposit feeder (T. arcuata) than the herbivorous P. plicatum. The results suggested that the discharge of dredged wastewater into mangroves resulted in the uptake of wastewater-derived materials and nutrients by mangrove crabs.
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Braquiuros , Aguas Residuales , Animales , Estanques , Alimentos Marinos , Ácidos GrasosRESUMEN
The combined influences of species selection (Avicennia marina, Kandelia obovata) and site elevation (BSL site, below local mean sea level; ASL site, above local mean sea level) on the greenhouse gas fluxes (nitrous oxide (N2O), methane (CH4) and carbon dioxide (CO2)) from restored mangrove soils are investigated in this study. Compared with the A. marina forest, soils in the K. obovata forest at ASL site have higher CO2 fluxes, while higher N2O fluxes in the K. obovata forest are found at BSL site. The highest CH4 fluxes are found at BSL site in the A. marina forest. At each elevation site, the A. marina forest has lower CO2-equivalent fluxes and carbon release in the form of carbon-containing gases. The results suggest that A. marina should be selected for mangrove restoration to minimize carbon release and reduce influence of greenhouse gas fluxes on the global greenhouse effect.
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Gases de Efecto Invernadero , Gases de Efecto Invernadero/análisis , Suelo , Dióxido de Carbono/análisis , Monitoreo del Ambiente , Estaciones del Año , Metano/análisis , Óxido Nitroso/análisisRESUMEN
BACKGROUND: Active hydrothermal vents create extreme conditions characterized by high temperatures, low pH levels, and elevated concentrations of heavy metals and other trace elements. These conditions support unique ecosystems where chemolithoautotrophs serve as primary producers. The steep temperature and pH gradients from the vent mouth to its periphery provide a wide range of microhabitats for these specialized microorganisms. However, their metabolic functions, adaptations in response to these gradients, and coping mechanisms under extreme conditions remain areas of limited knowledge. In this study, we conducted temperature gradient incubations of hydrothermal fluids from moderate (pH = 5.6) and extremely (pH = 2.2) acidic vents. Combining the DNA-stable isotope probing technique and subsequent metagenomics, we identified active chemolithoautotrophs under different temperature and pH conditions and analyzed their specific metabolic mechanisms. RESULTS: We found that the carbon fixation activities of Nautiliales in vent fluids were significantly increased from 45 to 65 °C under moderately acidic condition, while their heat tolerance was reduced under extremely acidic conditions. In contrast, Campylobacterales actively fixed carbon under both moderately and extremely acidic conditions under 30 - 45 °C. Compared to Campylobacterales, Nautiliales were found to lack the Sox sulfur oxidation system and instead use NAD(H)-linked glutamate dehydrogenase to boost the reverse tricarboxylic acid (rTCA) cycle. Additionally, they exhibit a high genetic potential for high activity of cytochrome bd ubiquinol oxidase in oxygen respiration and hydrogen oxidation at high temperatures. In terms of high-temperature adaption, the rgy gene plays a critical role in Nautiliales by maintaining DNA stability at high temperature. Genes encoding proteins involved in proton export, including the membrane arm subunits of proton-pumping NADH: ubiquinone oxidoreductase, K+ accumulation, selective transport of charged molecules, permease regulation, and formation of the permeability barrier of bacterial outer membranes, play essential roles in enabling Campylobacterales to adapt to extremely acidic conditions. CONCLUSIONS: Our study provides in-depth insights into how high temperature and low pH impact the metabolic processes of energy and main elements in chemolithoautotrophs living in hydrothermal ecosystems, as well as the mechanisms they use to adapt to the extreme hydrothermal conditions. Video Abstract.
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Epsilonproteobacteria , Respiraderos Hidrotermales , Ecosistema , Temperatura , Protones , Carbono/metabolismo , ADN , Respiraderos Hidrotermales/microbiología , FilogeniaRESUMEN
Waterbirds are vital to coastal wetland ecosystem, and play significant roles in global biodiversity maintenance, cultural and educational services, etc. Waterbirds are particularly vulnerable to environmental change, particularly land-cover change, which has severely degraded their ecological niches. Accordingly, this study developed a waterbird-habitat preference index to quantify waterbird dependence on Xiamen Bay's habitats and a subsidiary waterbird-specific habitat suitability index to predict potential effects of future land-cover change on waterbirds. Results showed that the waterbird-habitat preference index ranged from -9.8 to 18.71, indicating that habitat selection varied greatly among different waterbird species, where tidal flats were the most popular waterbird habitat. Additionally, most waterbird species showed a preference for more than one habitat, which could be indicative of their diverse ecological demands. Effects on waterbirds varied greatly among the three different land-cover scenarios, where positive benefits were predicted under the ecological protection scenario (EPS), while the greatest negative effects were observed under the development and utilization scenario (DUS). Effects also varied among different waterbirds species. Those under the current trend scenario (CTS) (e.g., Tringa brevipes and Calidris ruficollis) could be at risk for species abundance loss (i.e., losers) while others (i.e., Egretta garzetta and Saundersilarus saundersi) could benefit from increased abundance (i.e., winners). Generally, migratory and traveling birds were much more vulnerable than resident birds. Spatially, conservation priority should be given to the Dadeng Waters and those waters adjacent to it (i.e., Tongan Bay and Anhai Bay) because of the highest waterbird loss risk in these areas under a conflict between an urgent need to protect waterbird biodiversity and intense present and future land-cover development. The intent of this study is to provide a useful tool to explore land-cover effects on waterbirds in similar coastal regions, which can provide important information on protection and restoration strategies.
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Charadriiformes , Ecosistema , Animales , Bahías , Estudios Prospectivos , Conservación de los Recursos Naturales , Biodiversidad , Humedales , China , AvesRESUMEN
Comparative study of macrofaunal assemblages in seagrass meadows and neighboring seabeds along the southeastern coast of Shandong Peninsula, China were performed. A total of 136 species were identified, including polychaetes (49 species), crustaceans (28), molluscs (58), and echinoderms (1). Species numbers of macrofauna in seagrass meadows and the neighboring seabeds were 52 and 65, respectively, whereas those in autumn were 90 and 56, respectively. Average macrofaunal abundances in spring in seagrass and neighboring seabeds were 2388.9 and 2516.7 ind./m2, respectively, whereas those in autumn were 11,689.0 and 1733.3 ind./m2, respectively. Ranges of species richness index, evenness index, and Shannon-Wiener index in seagrass meadows and the neighboring seabeds were 1.3-2.7, 0.7-0.9, 2.8-3.8, and 1.04-2.4, 0.5-0.9, 1.6-3.4 during spring, whereas those in autumn were 0.1-4.2, 0.3-0.8, 0.8-3.6 and 1.4-3.5, 0.5-0.9, 2.2-4.5. Bottom water temperature, salinity, sediment chlorophyll a concentration, and water content were the most important environmental factors influencing macrofaunal assemblages.
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Equinodermos , Ecosistema , Animales , Clorofila A , Agua , ChinaRESUMEN
Atmospheric greenhouse gas (GHG) emissions from seagrass meadows that determine the ecosystem atmospheric cooling effect have rarely been quantified. This study measured the simultaneous fluxes direct to the atmosphere of three GHGs (CO2, CH4 and N2O) within a Halophila beccarii seagrass meadow and an adjacent unvegetated bare intertidal flat, and their relationships to seagrass abundance and relevant soil parameters. The results showed that seasonal variation in seagrass abundance was strongly linked with the CO2 exchange rate. The CH4 and N2O fluxes were similarly low at both sites and comparable between winter and summer. The global warming potential of CH4 and N2O reduced the ecosystem CO2 uptake by only 5 % at the seagrass site. The results indicated that the H. beccarii meadow had a stronger atmospheric cooling effect than the bare flat and that the seagrass-mediated CO2 flux in this oligotrophic seagrass meadow primarily determined the atmospheric cooling effect.
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Dióxido de Carbono , Ecosistema , Dióxido de Carbono/análisis , Metano/análisis , Óxido Nitroso/análisis , Monitoreo del Ambiente , SueloRESUMEN
Although evidence suggests the ubiquity of meso- and microplastics (MMPs) in mangrove forests, our knowledge of their bioavailability and risk on mangrove leaves is scarce. Here, we investigated MMP contamination concerning submerged mangrove leaves and herbivorous snails that mainly feed on them from the four mangrove forests located in Beibu Gulf, Guangxi Province, China. Results showed that the MMP abundance on the mangrove leaves ranged from 0.01 ± 0.00 to 0.42 ± 0.15 items cm-2, while it ranged from 0.33 ± 0.21 to 6.20 ± 2.91 items individual-1 in the snails. There were significant positive correlations between snails and leaves regarding the abundance of total MMPs and the proportions of MMPs with the same characteristics. Expanded polystyrene (EPS) that mainly derived from aquaculture rafts, accounted for a major component both on the leaves and in the snails in Shi Jiao (SJ). Both the detection frequency and percentage of larger EPS (2.00-17.50 mm) on the leaves in SJ were higher than other sites. Meanwhile, the detection frequency, abundance and percentage of larger EPS on the leaves had significant positive correlations with those of micro-EPS in the snails. These findings suggested that mangrove leaves may represent a viable pathway for MMPs to enter the herbivorous snails. Larger EPS with higher frequency of occurrence on mangrove leaves were more likely to be encountered and ingested by snail considering its opportunistic feeding behavior. In addition, 11 sensitive genes involved in the processes of metabolism, intestinal mucosal immune systems, and cellular transduction in the snails were significantly suppressed by MMP exposure, which may be potentially used as early biomarkers to indicate the biological effects of MMPs under realistic environmental conditions. Overall, this study provides novel insights into the fate, sources, and biological effects of MMPs on mangrove leaves.
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Microplásticos , Plásticos , Monitoreo del Ambiente/métodos , China , Humedales , Poliestirenos/análisisRESUMEN
Habitat loss and degradation of mangrove forests can be caused by both sea level rise (SLR) and unsustainable land practices. Current long-term change projections are often based on changes to mangrove extent; however, this may overlook fragmentation and the associated habitat resilience decline and therefore fail to adequately reveal the risks to mangrove habitats. A mangrove sustainability index (MSI) was proposed in this study to assess the impact of SLR and land use on mangrove habitats. The index consists of four components: habitat area change, habitat quality, landscape pattern, and protection ratio. Ecological models and landscape models were combined to calculate the MSI. Considering the SLR under RCP4.5 and RCP8.5 and land use strategies, four scenarios were set with prediction periods of base year (2020) to 2050 and 2100. The Leizhou Peninsula, China was used as the case study. The results showed that dual stressors would reduce the extent of mangroves by 16.6%-56.2%. Habitat quality was sensitive to land use change but was not affected by SLR. Landscape pattern and protection ratio were influenced by SLR but less effected by land use. In all scenarios, mangroves tended to migrate out of the protected areas, with protection ratio decreasing from 37% to 16.9%-29.9%. Newly expanding habitats may suffer from patch fragmentation and low connectivity. Unsustainable mangrove distribution sites on Leizhou Peninsula were identified as hotspots for management. Projections under different scenarios showed that some unsustainable sites could be reversed to sustainable sites through improvements in land use policies. The proposed approach could provide essential tools for the formulation of mangrove conservation and restoration strategies adapted to climate change.
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Conservación de los Recursos Naturales , Elevación del Nivel del Mar , Cambio Climático , Humedales , Ecosistema , ChinaRESUMEN
The Ovulidae (Gastropoda, Cypraeoidea) is a family of small to medium Mollusca in the order Littorinimorpha, and Sandalia is a very small genus containing only three extant species. In the present study, 132 specimens of Ovulidae were collected, belonging to seven genera and nine species, including 54 Sandaliabridgesi and three Sandaliatriticea individuals. The cytochrome c oxidase I gene, 16S rRNA, and ITS1-5.8S-ITS2 sequences were obtained from all specimens and compared with sequences downloaded from GenBank to calculate genetic distances and construct phylogenetic trees. The sequences of S.bridgesi and S.triticea exhibited a high degree of similarity, and S.bridgesi does not form a separate clade, supporting the proposal that S.bridgesi should be synonymised with S.triticea.
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In 2003, Kandelia obovata was identified as a new mangrove species differentiated from Kandelia candel. However, little is known about their chloroplast (cp) genome differences and their possible ecological significance. In this study, 25 whole cp genomes, with seven samples of K. candel from Malaysia, Thailand, and Bangladesh and 18 samples of K. obovata from China, were sequenced for comparison. The cp genomes of both species encoded 128 genes, namely 83 protein-coding genes, 37 tRNA genes, and eight rRNA genes, but the cp genome size of K. obovata was ~2 kb larger than that of K. candle due to the presence of more and longer repeat sequences. Of these, tandem repeats and simple sequence repeats exhibited great differences. Principal component analysis based on indels, and phylogenetic tree analyses constructed with homologous protein genes from the single-copy genes, as well as 38 homologous pair genes among 13 mangrove species, gave strong support to the separation of the two species within the Kandelia genus. Homologous genes ndhD and atpA showed intraspecific consistency and interspecific differences. Molecular dynamics simulations of their corresponding proteins, NAD(P)H dehydrogenase chain 4 (NDH-D) and ATP synthase subunit alpha (ATP-A), predicted them to be significantly different in the functions of photosynthetic electron transport and ATP generation in the two species. These results suggest that the energy requirement was a pivotal factor in their adaptation to differential environments geographically separated by the South China Sea. Our results also provide clues for future research on their physiological and molecular adaptation mechanisms to light and temperature.
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Two bacterial strains, designated as 1-4-3T and 1-4-4, were isolated from a mangrove sediment cultured with coastal seawater. The cells were Gram-stain-negative, motile, short, rod-shaped bacteria with flagella. Growth occurred at 4-37 °C, pH 7.0-9.0, and 0-7% NaCl. The predominant fatty acids of the novel strains were C18â:â1 ω7c, C19â:â0 cyclo ω8c, C18â:â0, and C16â:â0. A phylogenetic analysis based on 16S rRNA gene sequences and whole genome phylogeny analysis based on distance matrix revealed an affiliation between the two strains and the genus Aureimonas, with closest sequence similarity to A. populi 4M3-2T (96.41 and 96.64% similarity, respectively) and A. glaciistagni (96.01 and 96.23% similarity, respectively). The DNA G+C content of strain 1-4-3T was 66.80 mol%. Strain 1-4-3T displayed low DNA-DNA relatedness to A. populi 4M3-2T, with an average nucleotide identity value of 77.47â% and digital DNA-DNA hybridization value of 22.83â%. Genotypic, chemotaxonomic, and phenotypic data indicate that strains 1-4-3T and 1-4-4 represent a novel species of the genus Aureimonas, for which we propose the name Aureimonas mangrovi sp. nov. The type strain is 1-4-3T (=LMG 31693T=CGMCC 1.18507T).
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Alphaproteobacteria/clasificación , Sedimentos Geológicos/microbiología , Filogenia , Agua de Mar/microbiología , Alphaproteobacteria/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Composición de Base , ADN Bacteriano/genética , Ácidos Grasos/química , Hibridación de Ácido Nucleico , Fosfolípidos/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Tailandia , HumedalesRESUMEN
Global mangrove forests have exhibited distinct changes in the past decades owing to anthropogenic activities, with land-use pressure being among the main causes of mangrove loss. Thus, understanding the inherent conflicts between conservation/restoration and land-use demands is fundamental for mangrove management. To predict how land-use changes will drive the spatiotemporal patterns of mangrove habitats, a novel integrated framework coupling MaxEnt and Dyna-CLUE modeling was proposed. The coupled model can identify suitable mangrove afforestation habitats and predict the impact of land-use change on potential mangrove habitats. In this study, the model was used to predict the mangrove habitat change in 2030 in the province with the most mangrove forests in China. The potential suitable habitat of 14 mangrove species under three coastal land-use scenarios were mapped using the coupled model. Under the current trend scenario, only 41.2% of the existing wetland would be retained, whereas the potential distribution area of all the mangrove species will decrease by an average of 30%. Under the sustainable development and ecological protection scenarios, the mangrove habitat could be increased by 11% to 61%, depending on the species. Different mangrove species showed varied sensitivity to the improved land-use policies, with several species being harder to restore than others, even under aggressive protection and restoration policies. The combined use of both MaxEnt and Dyna-CLUE models proved complementary and offered insights into the impacts of different land-use policies on the spatiotemporal change of mangrove habitats.
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INTRODUCTION: The epithelial tight junctions of intestine were impaired in murine model of type 2 diabetes mellitus (T2DM). The aim of this work was to investigate the alteration of intestinal barrier in T2DM patients. METHODS: 90 patients with T2DM and 28 healthy controls were recruited. Serum lipopolysaccharide (LPS), Zonulin, and intestinal fatty acid binding protein (IFABP) were measured by ELISA, based on which a derived permeability risk score (PRS) was calculated. Subgroup analyses were conducted based on the glycemic control (HbA1câ¯<â¯7%, or HbA1câ¯≥â¯7%), the amount of chronic diabetic complications, and the use of aspirin at the time. RESULTS: Serum LPS, Zonulin, and IFABP, and PRS of T2DM group were significantly higher than those of the control group (pâ¯<â¯0.05 for all). Serum LPS and PRS was higher in T2DM patients with poor glycemic control (both pâ¯<â¯0.05). Patients with more chronic complications of diabetes had higher serum LPS and IFABP, and PRS (all pâ¯<â¯0.05). No differences were found in these serum markers between T2DM patients being treated with aspirin or not. CONCLUSIONS: Intestinal barrier function was impaired in T2DM patients. Poor glycemic control and more chronic complications of diabetes were associated with worse intestinal barrier function. Treatment with aspirin did not aggravate the impairment of intestinal barrier in T2DM patients.
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Diabetes Mellitus Tipo 2 , Proteínas de Unión a Ácidos Grasos/sangre , Mucosa Intestinal/fisiopatología , Lipopolisacáridos , Precursores de Proteínas/sangre , Aspirina/uso terapéutico , Diabetes Mellitus Tipo 2/complicaciones , Hemoglobina Glucada , Control Glucémico , Haptoglobinas , Humanos , Mucosa Intestinal/metabolismo , Lipopolisacáridos/sangreRESUMEN
Exosomes derived from human umbilical cord mesenchymal stem cells (hucMSCs) expressing microRNAs (miRNAs) have been highlighted in human cancers. However, the detailed molecular mechanism of hucMSCs-derived exosomal miR-451a on hepatocellular carcinoma (HCC) remains further investigation. Our study aims to explore the impact of exosomal miR-451a on the progression of HCC. Expression of miR-451a and a disintegrin and metalloprotease 10 (ADAM10) in HCC tissues and adjacent normal tissues were determined. The exosomes were extracted from hucMSCs and co-cultured with Hep3B and SMMC-7721 cell lines. After the treatment of relative exosomes or exosome inhibitor GW4869 in Hep3B and SMMC-7721 cells, the paclitaxel resistance and malignant phenotypes of HCC cells were measured. Moreover, the effect of hucMSCs-derived exosomes on the expression of miR-451a and ADAM10 in HCC cells was assessed. The targeting relationship between miR-451a and ADAM10 was verified to detect the impact of ADAM10-wild type and ADAM10-mutant type (MUT) on HCC cell processes. Low expression of miR-451a and high expression of ADAM10 indicated a poor prognosis of HCC patients. MiR-451a was up-regulated while ADAM10 was down-regulated in HCC cells after co-culture with HucMSC-derived exosomes. The exosomes elevated miR-451a and inhibited ADAM10 to suppress the paclitaxel resistance, cell cycle transition, proliferation, migration and invasion, and promote apoptosis of HCC cells. ADAM10 was verified to be a target gene of miR-451a. ADAM10-MUT promoted HCC process independent of miR-451a mimic. HucMSC-derived exosomal miR-451a could restrict the epithelial-mesenchymal transition of HCC cells by targeting ADAM10, which might provide new targets for HCC treatment.
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Proteína ADAM10/genética , Secretasas de la Proteína Precursora del Amiloide/genética , Carcinoma Hepatocelular/patología , Resistencia a Antineoplásicos , Exosomas/genética , Neoplasias Hepáticas/patología , Proteínas de la Membrana/genética , MicroARNs/genética , Cordón Umbilical/citología , Adulto , Anciano , Compuestos de Anilina/farmacología , Compuestos de Bencilideno/farmacología , Carcinoma Hepatocelular/genética , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Células Cultivadas , Técnicas de Cocultivo , Transición Epitelial-Mesenquimal , Exosomas/efectos de los fármacos , Femenino , Regulación Neoplásica de la Expresión Génica , Células Hep G2 , Humanos , Neoplasias Hepáticas/genética , Masculino , Células Madre Mesenquimatosas/química , Células Madre Mesenquimatosas/citología , Persona de Mediana Edad , Paclitaxel/farmacología , Pronóstico , Análisis de Supervivencia , Cordón Umbilical/químicaRESUMEN
The present study compared the ecosystem organic carbon (OC) stocks and soil OC sources between two 12-year-old monospecific mangrove sites comprised of different species (Kandelia obovata in tree form and Aegiceras corniculatum in shrub form). We tested whether the carbon sequestration performance following rehabilitation varied with plantation of species in different forms and whether mangrove vegetation sequestrate OC more rapidly than soil pool. The results showed that mangrove rehabilitation increased the ecosystem OC stock relative to that of a non-vegetated bare flat. The accumulation of soil carbon was accompanied by increased soil total nitrogen contents and decreased δ13C values of soil OC, indicating that the increases in OC and TN contents were a function of accumulation of 13C-depleted mangrove materials in the soil. The sequestrated OC over the 12 years was considerably less in soil than in biomass at each mangrove site, suggesting that mangrove vegetation contributes more rapidly than the soil to ecosystem OC sequestration following rehabilitation before the vegetation has reached maturity. Compilation of the carbon stocks from worldwide rehabilitated mangrove forests with various ages further supports this finding. The K. obovata site had an apparently higher biomass OC stock but less OC in the soil than those at the A. corniculatum site. There was a higher standing leaf litter stock on the forest floor and more mangrove materials incorporated into the top 15 cm soil at the A. corniculatum site. These results suggested that the two rehabilitated mangrove sites had different development trajectories of both biomass and soil OC sequestration. Moreover, the performance of ecosystem carbon sequestration was related to plantation of different mangrove species. These carbon sequestration feature of rehabilitated mangrove forests therefore deserve attention in future rehabilitation programs to promote carbon sequestration performance.