Project description:Background: The soil environment is responsible for sustaining most terrestrial plant life on earth, yet we know surprisingly little about the important functions carried out by diverse microbial communities in soil. Soil microbes that inhabit the channels of decaying root systems, the detritusphere, are likely to be essential for plant growth and health, as these channels are the preferred locations of new root growth. Understanding the microbial metagenome of the detritusphere and how it responds to agricultural management such as crop rotations and soil tillage will be vital for improving global food production. Methods: The rhizosphere soils of wheat and chickpea growing under + and - decaying root were collected for metagenomics sequencing. A gene catalogue was established by de novo assembling metagenomic sequencing. Genes abundance was compared between bulk soil and rhizosphere soils under different treatments. Conclusions: The study describes the diversity and functional capacity of a high-quality soil microbial metagenome. The results demonstrate the contribution of the microbiome from decaying root in determining the metagenome of developing root systems, which is fundamental to plant growth, since roots preferentially inhabit previous root channels. Modifications in root microbial function through soil management, can ultimately govern plant health, productivity and food security.
Project description:Large amounts of carbon sequestered in permafrost are becoming available for microbial degradation. We investigated 1,529 microbial metagenome-assembled genomes recovered from our site to understand carbon processing in this environment. Metabolic reconstruction, supported by metatranscriptomic and metaproteomic data, revealed key populations involved in organic matter degradation, including bacteria encoding a pathway for xylose degradation only previously identified in fungi.
Project description:Sequencing the metatranscriptome can provide information about the response of organisms to varying environmental conditions. We present a methodology for obtaining random whole-community mRNA from a complex microbial assemblage using Pyrosequencing. The metatranscriptome had, with minimum contamination by ribosomal RNA, significant coverage of abundant transcripts, and included significantly more potentially novel proteins than in the metagenome. Keywords: metatranscriptome, mesocosm, ocean acidification
Project description:The deep marine subsurface is one of the largest unexplored biospheres on Earth, where members of the phylum Chloroflexi are abundant and globally distributed. However, the deep-sea Chloroflexi have remained elusive to cultivation, hampering a more thorough understanding of their metabolisms. In this work, we have successfully isolated a representative of the phylum Chloroflexi, designated strain ZRK33, from deep-sea cold seep sediments. Phylogenetic analyses based on 16S rRNA genes, genomes, RpoB and EF-tu proteins indicated that strain ZRK33 represents a novel class within the phylum Chloroflexi, designated Sulfochloroflexia. We present a detailed description of the phenotypic traits, complete genome sequence and central metabolisms of the novel strain ZRK33. Notably, sulfate and thiosulfate could significantly promote the growth of the new isolate, possibly through accelerating the hydrolysis and uptake of saccharides. Thus, this result reveals that strain ZRK33 may play a crucial part in sulfur cycling in the deep-sea environments. Moreover, the putative genes associated with assimilatory and dissimilatory sulfate reduction are broadly distributed in the genomes of 27 metagenome-assembled genomes (MAGs) from deep-sea cold seep and hydrothermal vents sediments. Together, we propose that the deep marine subsurface Chloroflexi play key roles in sulfur cycling for the first time. This may concomitantly suggest an unsuspected availability of sulfur-containing compounds to allow for the high abundance of Chloroflexi in the deep sea.
Project description:<p>A variety of anthropogenic organohalide contaminants generated from industry are released into the environment, and thus cause serious pollution that endangers human health. In the present study, we investigated the microbial community composition of industrial saponification wastewater using 16S rRNA sequencing, providing genomic insights of potential organohalide dehalogenation bacteria (OHDBs) by whole-metagenome sequencing. We also explored yet-to-culture OHDBs involved in the microbial community. Microbial diversity analysis reveals that Proteobacteria and Patescibacteria phyla dominate microbiome abundance of the wastewater. In addition, a total of six bacterial groups (Rhizobiales, Rhodobacteraceae, Rhodospirillales, Flavobạcteriales, Micrococcales, and Saccharimonadales) were found as biomarkers in the key organohalide removal module. Ninety-four metagenome-assembled genomes (MAGs) were reconstructed from the microbial community, and 105 hydrolytic dehalogenase genes within 42 MAGs were identified, suggesting that the potential for hydrolytic organohalide dehalogenation is present in the microbial community. Subsequently, we characterized the organohalide dehalogenation of an isolated OHDB, Microbacterium sp. J1-1, which shows the dehalogenation activities of chloropropanol, dichloropropanol, and epichlorohydrin. This study provides a community-integrated multi-omics approach to gain functional OHDBs for industrial organohalide dehalogenation.</p>
2022-11-21 | MTBLS3916 | MetaboLights
Project description:Microbial and Metazoan Diversity from the Ballast Water
Project description:Salt marshes provide many key ecosystem services that have tremendous ecological and economic value. One critical service is the removal of fixed nitrogen from coastal waters, which limits the negative effects of eutrophication resulting from increased nutrient supply. Nutrient enrichment of salt marsh sediments results in higher rates of nitrogen cycling and, commonly, a concurrent increase in the flux of nitrous oxide, an important greenhouse gas. Little is known, however, regarding controls on the microbial communities that contribute to nitrous oxide fluxes in marsh sediments. To address this disconnect, we generated microbial community profiles as well as directly assayed nitrogen cycling genes that encode the enzymes responsible for overall nitrous oxide flux from salt marsh sediments. We hypothesized that communities of microbes responsible for nitrogen transformations will be structured by nitrogen availability. Taxa that respond positively to high nitrogen inputs may be responsible for the elevated rates of nitrogen cycling processes measured in fertilized sediments. Our data show that, with the exception of ammonia-oxidizing archaea, the community composition of organisms responsible for production and consumption of nitrous oxide was altered under nutrient enrichment. These results suggest that elevated rates of nitrous oxide production and consumption are the result of changes in community structure, not simply changes in microbial activity.
Project description:To study the responses of microbial communities to short-term nitrogen addition and warming,here we examine microbial communities in mangrove sediments subjected to a 4-months experimental simulation of eutrophication with 185 g m-2 year-1 nitrogen addition (N), 3oC warming (W) and nitrogen addition*warming interaction (NW).