RESUMEN
In recent decades, the reclamation of lakes has captured 42% of the total lake area of the Yangtze Plain in China and introduced additional pressure on lacustrine water quality. While lacustrine dissolved organic matter (DOM) is critical in regulating biogeochemical processing and aquatic biodiversity, the impact of reclamation on the molecular-level characteristics of lacustrine DOM remains unexplored. Here, the DOM characteristics altered by reclamation practices in the Yangtze Plain lakes were investigated using fluorescence spectroscopy, nuclear magnetic resonance spectroscopy, and Fourier transform ion cyclotron resonance mass spectrometry. Results demonstrated that reclamation not only elevated the quantity (on average +32%) but also altered the characteristics and composition of lacustrine DOM. Compared to the natural water sites close by, reclamation sites did not significantly alter the DOM aromaticity but significantly lowered the average molecular weight and increased the biolability of DOM. The chromophoric DOM and humic-like fluorescent components were remarkably elevated, but not the protein-like fluorescent components. More lipid-like and condensed aromatic-like components were detected in the lacustrine DOM as compared to the lignin-like, carbohydrate-like, and protein-like components, which may be driven by the increased microbial processing. Overall, the significant alteration in characteristics and composition of lacustrine DOM highlights the potential impact of reclamation on the DOM biogeochemical cycle and the environmental quality in aquatic ecosystems.
Asunto(s)
Materia Orgánica Disuelta , Ecosistema , China , Lagos/química , Espectrometría de Fluorescencia/métodos , Calidad del AguaRESUMEN
The reduction in gut microbiota diversity is associated with a range of human diseases. Overuse of antibiotics has been associated with a diminished gut-microbial diversity in humans and may promote microbiota-associated negative effects to physical health, such as the metabolic syndrome-cluster of diseases and mental illnesses. There is a pressing need to deepen the understanding of the effects of antibiotics at the biochemical level. The current study investigated metabolic effects of two widely prescribed antibiotics-vancomycin and ciprofloxacin-on biofluids and brain tissue samples of NMRI female mice using a 1H nuclear magnetic resonance (NMR) spectroscopy-based metabolic profiling approach. While both antibiotics significantly affected the host metabolic signatures of urine and feces, only ciprofloxacin induced metabolic changes in plasma. Metabolic perturbations were pronounced 1 day post-treatment, reverting back to baseline at day 20 post-treatment. Both antibiotics induced changes in the choline metabolism, host-microbial cometabolites, short chain fatty acid production, and protein/purine degradation. The metabolic profiles of brain tissue aqueous extracts did not show any antibiotics-related changes by day 20 post-treatment. The data suggest that the metabolic disruptions in biofluids caused by antibiotics are reversed by day 20 post-treatment when compared to the pre-treatment profiles.
Asunto(s)
Ciprofloxacina/farmacología , Microbioma Gastrointestinal/efectos de los fármacos , Metaboloma/efectos de los fármacos , Metabolómica/métodos , Vancomicina/farmacología , Animales , Antibacterianos/farmacología , Líquidos Corporales/efectos de los fármacos , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Femenino , Microbioma Gastrointestinal/fisiología , Humanos , Espectroscopía de Resonancia Magnética , Ratones , Ratones EndogámicosRESUMEN
Microalgae are promising candidate resources from marine ecology for health-improving effects. Metabolite profiling of the microalgal diatom, Chaetoceros calcitrans was conducted by using robust metabolomics tools, namely ¹H nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate data analysis (MVDA). The unsupervised data analysis, using principal component analysis (PCA), resolved the five types of extracts made by solvents ranging from polar to non-polar into five different clusters. Collectively, with various extraction solvents, 11 amino acids, cholesterol, 6 fatty acids, 2 sugars, 1 osmolyte, 6 carotenoids and 2 chlorophyll pigments were identified. The fatty acids and both carotenoid pigments as well as chlorophyll, were observed in the extracts made from medium polar (acetone, chloroform) and non-polar (hexane) solvents. It is suggested that the compounds were the characteristic markers that influenced the separation between the clusters. Based on partial least square (PLS) analysis, fucoxanthin, astaxanthin, violaxanthin, zeaxanthin, canthaxanthin, and lutein displayed strong correlation to 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and nitric oxide (NO) inhibitory activity. This metabolomics study showed that solvent extractions are one of the main bottlenecks for the maximum recovery of bioactive microalgal compounds and could be a better source of natural antioxidants due to a high value of metabolites.