The dynamics of nitrogen (N) loss in the ocean's oxygen-deficient zones (ODZs) are thought to be driven by climate impacts on ocean circulation and biological productivity. Here we analyze a data-constrained model of the microbial ecosystem in an ODZ and find that species interactions drive fluctuations in local- and regional-scale rates of N loss, even in the absence of climate variability. By consuming O to nanomolar levels, aerobic nitrifying microbes cede their competitive advantage for scarce forms of N to anaerobic denitrifying bacteria. Because anaerobes cannot sustain their own low-O niche, the physical O supply restores competitive advantage to aerobic populations, resetting the cycle. The resulting ecosystem oscillations induce a unique geochemical signature within the ODZ-short-lived spikes of ammonium that are found in measured profiles. The microbial ecosystem dynamics also give rise to variable ratios of anammox to heterotrophic denitrification, providing a mechanism for the unexplained variability of these pathways observed in the ocean.
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http://dx.doi.org/10.1073/pnas.1818014116 | DOI Listing |
BMC Plant Biol
January 2025
Hebei Agricultural University, Baoding, China.
Background: Nitrogen (N) deposition has become a major driving factor affecting the balance of terrestrial ecosystems, changing the soil environment, element balance and species coexistence relationships, driving changes in biodiversity and ecosystem structure and function. Human-induced nitrogen input leads to a high NH/ NO ratio in soil. However, relatively few studies have investigated the effects of different nitrogen sources on forest plant-microbial symbionts.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Life Sciences and Systems Biology, University of Turin, Turin, Italy.
Soil is one of the most important reservoirs of antibiotic resistance, global threat that needs to be addressed with the One Health approach. Despite urban parks playing a fundamental role in urban ecosystems, the diffusion, maintenance, and human impact of antibiotic-resistance genes in this substrate are still poorly addressed. To fill in this gap, we adopted a molecular and culturomics approach to study antibiotic resistance in urban parks, accounting for the environmental matrix and the level of urbanization.
View Article and Find Full Text PDFNat Food
January 2025
State Key Laboratory for Crop Stress Resistance and High-Efficiency Production, Shaanxi Key Laboratory of Agricultural and Environmental Microbiology, College of Life Sciences, Northwest A&F University, Yangling, People's Republic of China.
Soils play a critical role in supporting agricultural production. Subsoils, below 20 cm, underpin fundamental agroecosystem sustainability traits including soil carbon storage, climate regulation and water provision. However, little is known about the ecological stability of subsoils in response to global change.
View Article and Find Full Text PDFCommun Biol
January 2025
Key Laboratory of Climate, Resources and Environment in Continental Shelf Sea and Deep Sea of Department of Education of Guangdong Province, Department of Oceanography, Key Laboratory for Coastal Ocean Variation and Disaster Prediction, College of Ocean and Meteorology, Guangdong Ocean University, Zhanjiang, China.
Leaf endospheres harbor diverse bacterial communities, comprising generalists and specialists, that profoundly affect ecosystem functions. However, the ecological dynamics of generalist and specialist leaf-endophytic bacteria and their responses to climate change remain poorly understood. We investigated the diversity and environmental responses of generalist and specialist bacteria within the leaf endosphere of mangroves across China.
View Article and Find Full Text PDFMycoses
January 2025
Cell Biology and Molecular Genetics, Yenepoya Research Centre, Yenepoya (Deemed to Be University), Mangalore, India.
A niche in the context of microorganisms defines the specific ecological role or habitat inhabited by microbial species within an ecosystem. For the human commensal Malassezia, the skin surface is considered its primary niche, where it adapts to the skin environment by utilising lipids as its main carbon and energy source. However pathogenic characteristics of Malassezia include the production of allergens, immune modulation and excessive lipid utilisation, which result in several diseases such as pityriasis versicolor, seborrheic dermatitis, Malassezia folliculitis and atopic dermatitis.
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