Project description:The response of soil microbial community to climate warming through both function shift and composition reorganization may profoundly influence global nutrient cycles, leading to potential significant carbon release from the terrain to the atmosphere. Despite the observed carbon flux change in northern permafrost, it remains unclear how soil microbial community contributes to this ecosystem alteration. Here, we applied microarray-based GeoChip 4.0 to investigate the functional and compositional response of subsurface (15~25cm) soil microbial community under about one year’s artificial heating (+2°C) in the Carbon in Permafrost Experimental Heating Research site on Alaska’s moist acidic tundra. Statistical analyses of GeoChip signal intensities showed significant microbial function shift in AK samples. Detrended correspondence analysis and dissimilarity tests (MRPP and ANOSIM) indicated significant functional structure difference between the warmed and the control communities. ANOVA revealed that 60% of the 70 detected individual genes in carbon, nitrogen, phosphorous and sulfur cyclings were substantially increased (p<0.05) by heating. 18 out of 33 detected carbon degradation genes were more abundant in warming samples in AK site, regardless of the discrepancy of labile or recalcitrant C, indicating a high temperature sensitivity of carbon degradation genes in rich carbon pool environment. These results demonstrated a rapid response of northern permafrost soil microbial community to warming. Considering the large carbon storage in northern permafrost region, microbial activity in this region may cause dramatic positive feedback to climate change, which is important and necessary to be integrated into climate change models.
Project description:Archaea are ubiquitous prokaryotes with a wide range of habitats, important roles in ecology, biotechnology and potentially even human health. Despite that, our understanding of archaeal cell biology is still rather limited, partially because the application of systems biology approaches is lacking behind the other domains of life. Here we introduce/announce the Archaeal Proteome Project (ArcPP), a community effort that aims for the comprehensive analysis of archaeal proteomes. Starting with the model archaeon Haloferax volcanii, we have re-analyzed more than 2 TB of MS result files (>20 Mio. spectra) using state-of-the-art bioinformatic tools, increasing peptide spectrum matches and leading to the secure identification of >3000 proteins. This dataset is part of the Archaeal Proteome Project dataset
Project description:Archaea, together with Bacteria, represent the two main divisions of life on Earth, with many of the defining characteristics of the more complex eukaryotes tracing their origin to evolutionary innovations first made in their archaeal ancestors. One of the most notable such features is nucleosomal chromatin, although archaeal histones and chromatin differ significantly from those of eukaryotes. Despite increased interest in archaeal histones in recent years, the properties of archaeal chromatin have been little studied using genomic tools. Here, we adapt the ATAC-seq assay to the archaeal context and use it to map the accessible landscape of the genome of the euryarchaeote Haloferax volcanii. We integrate the resulting datasets with genome-wide maps of active transcription and single-stranded DNA (ssDNA), and find that while H. volcanii promoters exist in a preferentially accessible state, modulation of transcriptional activity is not associated with changes in promoter accessibility, unlike the typical situation in eukaryotes. Applying orthogonal single-molecule footprinting methods, we quantify the absolute levels of physical protection of H. volcanii, and find that archaeal nucleosomal chromatin is at its baseline comparably to slightly more open than that of eukaryotes. We also evaluate the degree of coordination of transcription within archaeal operons and make the unexpected observation that some CRISPR arrays are associated with highly prevalent ssDNA structures. These results provide a foundation for the future functional studies of archaeal chromatin.
2022-10-01 | GSE207470 | GEO
Project description:Study of archaeal community in paddy soil under long-term fertilization
Project description:Purpose: Identification of transcriptionally active genes in the unculturable community constituent, Smithella, during hexadecane degradation; Differential gene expression analysis of hexadecane-relevant genes acoss three different conditions; Extension of metatranscriptomic datasets to other community constituents to identify interspecies relationships.