The objective of this study was to explore the long-term effects of different organic and inorganic fertilizers on activity and composition of the denitrifying and total bacterial communities in arable soil. Soil from the following six treatments was analyzed in an experimental field site established in 1956: cattle manure, sewage sludge, Ca(NO3)2, (NH4)2SO4, and unfertilized and unfertilized bare fallow. All plots but the fallow were planted with corn. The activity was measured in terms of potential denitrification rate and basal soil respiration. The nosZ and narG genes were used as functional markers of the denitrifying community, and the composition was analyzed using denaturing gradient gel electrophoresis of nosZ and restriction fragment length polymorphism of narG, together with cloning and sequencing. A fingerprint of the total bacterial community was assessed by ribosomal intergenic spacer region analysis (RISA). The potential denitrification rates were higher in plots treated with organic fertilizer than in those with only mineral fertilizer. The basal soil respiration rates were positively correlated to soil carbon content, and the highest rates were found in the plots with the addition of sewage sludge. Fingerprints of the nosZ and narG genes, as well as the RISA, showed significant differences in the corresponding communities in the plots treated with (NH4)2SO4 and sewage sludge, which exhibited the lowest pH. In contrast, similar patterns were observed among the other four treatments, unfertilized plots with and without crops and the plots treated with Ca(NO3)2 or with manure. This study shows that the addition of different fertilizers affects both the activity and the composition of the denitrifying communities in arable soil on a long-term basis. However, the treatments in which the denitrifying and bacterial community composition differed the most did not correspond to treatments with the most different activities, showing that potential activity was uncoupled to community composition.
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http://dx.doi.org/10.1128/AEM.71.12.8335-8343.2005 | DOI Listing |
Chem Commun (Camb)
January 2025
Graphene Composite Research Center, College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen, 518060, P. R. China.
In this study, a distinctive multiple core-shell structure of Co nanoparticles inserted into N-doped carbon dodecahedron@Co hydroxide (Co/NCD@Co(OH)) was synthesized a spontaneous redox reaction between metallic Co and NO, ultimately materializing the fine dispersion and exposure of the active sites. The electronic interaction existing between the Co/NCD core and the Co(OH) shell brings a synergistic effect, conspicuously lessens the overpotential, and reinforces the yield-rate and faradaic efficiency of NH for electrochemical nitrate-ammonia conversion. This study underlines the spontaneous redox between the catalysts and substrate, rendering it as a synthetic strategy for designing genuine and well-dispersed active sites.
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February 2025
Department of Anesthesiology, Renji Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
Background: Cell therapy demonstrates promising potential as a substitute therapeutic approach for liver cirrhosis. We have developed a strategy to effectively expand murine and human hepatocyte-derived liver progenitor-like cells (HepLPCs) in vitro. The primary objective of the present study was to apply HepLPCs to the treatment of liver cirrhosis and to elucidate the underlying mechanisms responsible for their therapeutic efficacy.
View Article and Find Full Text PDFPhysiol Rep
February 2025
Motion and Exercise Science, University of Stuttgart, Stuttgart, Germany.
The maintenance of an appropriate ratio of body fat to muscle mass is essential for the preservation of health and performance, as excessive body fat is associated with an increased risk of various diseases. Accurate body composition assessment requires precise segmentation of structures. In this study we developed a novel automatic machine learning approach for volumetric segmentation and quantitative assessment of MRI volumes and investigated the efficacy of using a machine learning algorithm to assess muscle, subcutaneous adipose tissue (SAT), and bone volume of the thigh before and after a strength training.
View Article and Find Full Text PDFmBio
January 2025
Department of Integrative Biology, University of California, Berkeley, Berkeley, California, USA.
The composition of the gut microbiome is determined by a complex interplay of diet, host genetics, microbe-microbe interactions, abiotic factors, and stochasticity. Previous studies have demonstrated the importance of host genetics in community assembly of the gut microbiome and identified a central role for DBL-1/BMP immune signaling in determining the abundance of gut . However, the effects of DBL-1 signaling on gut bacteria were found to depend on its activation in extra-intestinal tissues, highlighting a gap in our understanding of the proximal factors that determine microbiome composition.
View Article and Find Full Text PDFmBio
January 2025
Centre for Microbiology and Environmental Systems Science, Department of Microbiology and Ecosystem Science, Division of Microbial Ecology, University of Vienna, Vienna, Austria.
Unlabelled: In the gut, microRNAs (miRNAs) produced by intestinal epithelial cells are secreted into the lumen and can shape the composition and function of the gut microbiome. Crosstalk between gut microbes and the host plays a key role in irritable bowel syndrome (IBS) and inflammatory bowel diseases, yet little is known about how the miRNA-gut microbiome axis contributes to the pathogenesis of these conditions. Here, we investigate the ability of miR-21, a miRNA that we found decreased in fecal samples from IBS patients, to associate with and regulate gut microbiome function.
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