Project description:Over 20% of Earth’s terrestrial surface is underlain by permafrost that represents one of the largest terrestrial carbon pools, with an estimated ~1700 Pg of carbon (C) contained in the upper 3 m of permafrost. Models estimate that C release from thawing permafrost might represent the largest new transfer of C from the biosphere to the atmosphere as the climate warms. Here we investigated microbial community phylogeny, genetic functional potential gene expression, and protein production patterns along a natural thaw gradient, including permafrost, the seasonally thawed active layer and nearby thawed thermokarst bog, using a combination of molecular “omics” approaches: metagenomics (MG), metatranscriptomics (MT) and metaproteomics (MP). Highlights from these analyses reveal energy yielding microbial processes and potential strategies for microbial survival in permafrost soils, and linkages between biogeochemical process rates and –omics measurements. The results provide new knowledge about microbial life and activity potential in permafrost, the potential importance of iron reduction as a survival strategy under frozen conditions in mineral soils, and the importance of methanogenesis following thaw. The multi-omics strategy demonstrated here enables better mechanistic understanding of the ecological strategies utilized by soil microbial communities in response to climate change. Associated metagenomics data available at the EBI Metagenomics portal under the accession number <a href="https://www.ebi.ac.uk/metagenomics/projects/SRP052575">SRP052575</a>.
Project description:Here, we applied a microarray-based metagenomics technology termed GeoChip 5.0 to examined functional gene structure of microbes in three biomes, including boreal, temperate and tropical area.
Project description:Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple studies and allow us to explore patterns of diversity at an unprecedented scale. The result is both a reference database giving global context to DNA sequence data and a framework for incorporating data from future studies, fostering increasingly complete characterization of Earth's microbial diversity.
Project description:Wetland microbiomes play a crucial role in the global carbon cycle by modulating soil organic carbon (SOC) and greenhouse gas (GHG) emissions. Understanding how microbial communities respond to environmental changes is essential for predicting wetland carbon fluxes under future climate scenarios. Here, we investigated the biogeochemistry of a temperate lacustrine wetland across four seasons and three soil depths, integrating greenhouse gas flux measurements, porewater metabolite profiles, metagenomics, metabolomics, and metaproteomics. While seasonal shifts in GHG fluxes and porewater chemistry were evident, microbial community composition and function were primarily structured by soil depth, suggesting resilience to short-term seasonal fluctuations. Depth-correlated microbial taxa and metabolic pathways revealed distinct stratification: surface soils were enriched in metabolically versatile Gammaproteobacteria capable of oxygen and nitrate respiration, as well as methane and sulfur oxidation, whereas deeper layers favored strict anaerobic metabolism, with increasing abundances of Anaerolinea and Methanomicrobia. Metabolomics showed an enrichment of purine nucleotides and amino acids at the surface, while deeper soils accumulated amino sugars and phenolic compounds, highlighting differences in carbon processing. Metaproteomics confirmed active metabolic pathways, linking functional potential to microbial activity. By integrating multi-omics with biogeochemical measurements, this study provides a system-level view of wetland microbial function and resilience, contributing to predictive models of wetland carbon cycling under future climate change.
The work (proposal:https://doi.org/10.46936/10.25585/60000490) conducted by the U.S. Department of Energy Joint Genome Institute (https://ror.org/04xm1d337), a DOE Office of Science User Facility, is supported by the Office of Science of the U.S. Department of Energy operated under Contract No. DE-AC02-05CH11231.
Project description:Aging-related cognitive decline is associated with changes across different tissues and the gut microbiome, including dysfunction of the gut-brain axis. However, only few studies have linked multi-organ alterations to cognitive decline during aging. Here we report a multi-omics analysis integrating metabolomics, transcriptomics, DNA methylation, and metagenomics data from hippocampus, liver, colon, and fecal samples of mice, correlated with cognitive performance in the Barnes Maze spatial learning task across different age groups. We identified 734 molecular features associated with cognitive rank within individual data layers, of which 227 features remain when integrating all data layers with each other. Among the single-layer predictors, several host and microbial features were highlighted, with host-associated markers being predominant. Host features associated with cognitive function mainly belong to innate and adaptive inflammatory activity (inflammaging) and developmental processes. Our findings suggest that cognitive decline in aging is tightly coupled to systemic, age-associated inflammation, potentially initiated by microbiome-driven gastrointestinal inflammatory activity, emphasizing a link between peripheral tissue alterations and brain function.
Project description:A high-density oligonucleotide microarray that targets functional genes in marine microbial community was designed as a result of a multi-institutional effort. The design is based on nucleotide sequence data obtained with metagenomics and metatranscriptomics. The chip targets ~20000 gene sequences represented by 145 gene categories relevant to microbial metabolism in the open ocean and coastal environments. The three domains of life and also viruses are represented on the chip. Using this microarray we were able to compare the functional responses of microbial communities to iron and phosphate enrichments in samples from the North Pacific Subtropical Gyre. The response was attributed to individual lineages of microorganisms including uncharacterized strains. Transcription of 68% of the gene probes was detected from a variety of microorganisms, and the patterns of gene transcription indicated a relief from iron limitation and transition into nitrogen limitation. When combined with physicochemical descriptions of each system, the use of microarrays can help to develop a comprehensive understanding of the changes in microbially-driven processes. We analyzed three samples amended with phosphate and two sample amended with iron (III) after 48h of incubation
Project description:Here, we applied a microarray-based metagenomics technology termed GeoChip 5.0 to examined functional gene structure of microbes in four lakes at low and high elevations of approximately 530 and 4,600 m a.s.l., respectively.
Project description:Here, we applied a microarray-based metagenomics technology termed GeoChip 5.0 to investigate spring microbial functional genes in mesocosm-simulated shallow lake ecosystems having been undergoing nutrient enrichment and warming for nine years.