Here, we present HetDA_MAG_SS10, a metagenome-assembled genome (MAG) from an enrichment of a heterocystous diazotroph originally living in association with spp. obtained near Station ALOHA in the North Pacific Ocean. HetDA_MAG_SS10, an alphaproteobacterium in the order , is proposed to be photoheterotrophic via rhodopsin and has the potential for dimethylsulfoniopropionate (DMSP) demethylation.
View Article and Find Full Text PDFHere, we present a draft genome in the order and family . This draft genome comes from an enrichment of a heterocystous, cyanobacterial diazotroph (HetDA) that was originally living in association with species. This organism is proposed to be an anoxygenic phototroph capable of dissimilatory nitrate reduction to ammonia (DNRA).
View Article and Find Full Text PDFMicrobiol Resour Announc
February 2023
Here, we describe the metagenome-assembled genome (MAG) HetDA_MAG_SS2, in the family . It was found in association with a HetDA cyanobiont isolated from a Station ALOHA colony. Annotation suggests that HetDA_MAG_SS2 is a chemoorganoheterotroph with the potential for lithoheterotrophy, containing genes for aerobic respiration, mixed acid fermentation, dissimilatory nitrate reduction to ammonium, and sulfide oxidation.
View Article and Find Full Text PDFWe present a metagenome-assembled genome (MAG), HetDA_MAG_MS8, that was determined to be unique via relative evolutionary divergence (RED) scores and average nucleotide identity (ANI) values. HetDA_MAG_MS8 is in the order , genus , and was assembled from a heterocytous cyanobiont enrichment from the Hawaii Ocean Time Series. HetDA_MAG_MS8 is predicted to be a facultative, aerobic, anoxygenic photolithoheterotroph that has the potential for sulfide oxidation and dimethylsulfoniopropionate (DMSP) synthesis.
View Article and Find Full Text PDFMicrobiol Resour Announc
January 2023
Here, we describe the metagenome-assembled genome (MAG) HetDA_MAG_MS6. HetDA_MAG_MS6 was obtained from an enrichment of the heterocystous diazotroph HetDA, which was isolated near Station ALOHA. The MAG was placed in the family and is predicted to be a chemoorganoheterotroph with the potential for ammonia uptake, phosphonate transport, and sulfolipid biosynthesis.
View Article and Find Full Text PDFDiazotrophic cyanobacteria play a vital role in the nitrogen influx of the global marine ecosystem. In July 2010, colonies of spp. were picked near Station ALOHA in the oligotrophic North Pacific Subtropical Gyre, and a novel heterocystous diazotroph (strain HetDA_MAG_MS3) belonging to the genus was found living in close association; it was cultured and sequenced.
View Article and Find Full Text PDFAerobic anoxygenic phototrophs (AAnPs) are common in marine environments and are associated with photoheterotrophic activity. To date, AAnPs that possess the potential for carbon fixation have not been identified in the surface ocean. Using the Tara Oceans metagenomic dataset, we have identified draft genomes of nine bacteria that possess the genomic potential for anoxygenic phototrophy, carbon fixation via the Calvin-Benson-Bassham cycle, and the oxidation of sulfite and thiosulfate.
View Article and Find Full Text PDFMicroorganisms play a crucial role in mediating global biogeochemical cycles in the marine environment. By reconstructing the genomes of environmental organisms through metagenomics, researchers are able to study the metabolic potential of Bacteria and Archaea that are resistant to isolation in the laboratory. Utilizing the large metagenomic dataset generated from 234 samples collected during the Tara Oceans circumnavigation expedition, we were able to assemble 102 billion paired-end reads into 562 million contigs, which in turn were co-assembled and consolidated in to 7.
View Article and Find Full Text PDFThe Expedition has provided large, publicly-accessible microbial metagenomic datasets from a circumnavigation of the globe. Utilizing several size fractions from the samples originating in the Mediterranean Sea, we have used current assembly and binning techniques to reconstruct 290 putative draft metagenome-assembled bacterial and archaeal genomes, with an estimated completion of ≥50%, and an additional 2,786 bins, with estimated completion of 0-50%. We have submitted our results, including initial taxonomic and phylogenetic assignments, for the putative draft genomes to open-access repositories for the scientific community to use in ongoing research.
View Article and Find Full Text PDFMetagenomics has become an integral part of defining microbial diversity in various environments. Many ecosystems have characteristically low biomass and few cultured representatives. Linking potential metabolisms to phylogeny in environmental microorganisms is important for interpreting microbial community functions and the impacts these communities have on geochemical cycles.
View Article and Find Full Text PDFAppl Environ Microbiol
July 2016
Unlabelled: The South Pacific Gyre (SPG) possesses the lowest rates of sedimentation, surface chlorophyll concentration, and primary productivity in the global oceans. As a direct result, deep-sea sediments are thin and contain small amounts of labile organic carbon. It was recently shown that the entire SPG sediment column is oxygenated and may be representative of up to a third of the global marine environment.
View Article and Find Full Text PDFRecent studies of bacterial speciation have claimed to support the biological species concept-that reduced recombination is required for bacterial populations to diverge into species. This conclusion has been reached from the discovery that ecologically distinct clades show lower rates of recombination than that which occurs among closest relatives. However, these previous studies did not attempt to determine whether the more-rapidly recombining close relatives within the clades studied may also have diversified ecologically, without benefit of sexual isolation.
View Article and Find Full Text PDFThe oceanic crust forms two thirds of the Earth's surface and hosts a large phylogenetic and functional diversity of microorganisms. While advances have been made in the sedimentary realm, our understanding of the igneous rock portion as a microbial habitat has remained limited. We present the first comparative metagenomic microbial community analysis from ocean floor basalt environments at the Lō'ihi Seamount, Hawai'i, and the East Pacific Rise (EPR; 9°N).
View Article and Find Full Text PDFUnderstanding the evolution of the free-living, cyanobacterial, diazotroph Trichodesmium is of great importance because of its critical role in oceanic biogeochemistry and primary production. Unlike the other >150 available genomes of free-living cyanobacteria, only 63.8% of the Trichodesmium erythraeum (strain IMS101) genome is predicted to encode protein, which is 20-25% less than the average for other cyanobacteria and nonpathogenic, free-living bacteria.
View Article and Find Full Text PDFBackground: The Gulf of Maine is an important biological province of the Northwest Atlantic with high productivity year round. From an environmental Sanger-based metagenome, sampled in summer and winter, we were able to assemble and explore the partial environmental genomes of uncultured members of the class Flavobacteria. Each of the environmental genomes represents organisms that compose less than 1% of the total microbial metagenome.
View Article and Find Full Text PDFThe National Science Foundation's EarthCube End User Workshop was held at USC Wrigley Marine Science Center on Catalina Island, California in August 2013. The workshop was designed to explore and characterize the needs and tools available to the community that is focusing on microbial and physical oceanography research with a particular emphasis on 'omic research. The assembled researchers outlined the existing concerns regarding the vast data resources that are being generated, and how we will deal with these resources as their volume and diversity increases.
View Article and Find Full Text PDFThe formation and maintenance of deep-sea ferromanganese/polymetallic nodules still remains a mystery 140 years after their discovery. The wealth of rare metals concentrated in these nodules has spurred global interest in exploring the mining potential of these resources. The prevailing theory of abiotic formation has been called into question and the role of microbial metabolisms in nodule development is now an area of active research.
View Article and Find Full Text PDFZetaproteobacteria are among the most prevalent Fe(II)-oxidizing bacteria (FeOB) at deep-sea hydrothermal vents; however, knowledge about their environmental significance is limited. We provide metagenomic insights into an iron mat at the Lō´ihi Seamount, Hawai´l, revealing novel genomic information of locally dominant Zetaproteobacteria lineages. These lineages were previously estimated to account for ~13% of all local Zetaproteobacteria based on 16S clone library data.
View Article and Find Full Text PDFThe genomes of the two closely related freshwater thermophilic cyanobacteria Synechococcus sp. strain JA-3-3Ab and Synechococcus sp. strain JA-2-3B'a(2-13) each host several families of insertion sequences (ISSoc families) at various copy numbers, resulting in an overall high abundance of insertion sequences in the genomes.
View Article and Find Full Text PDFSince the days of Darwin, scientists have used the framework of the theory of evolution to explore the interconnectedness of life on Earth and adaptation of organisms to the ever-changing environment. The advent of molecular biology has advanced and accelerated the study of evolution by allowing direct examination of the genetic material that ultimately determines the phenotypes upon which selection acts. The study of evolution has been furthered through examination of microbial evolution, with large population numbers, short generation times, and easily extractable DNA.
View Article and Find Full Text PDFThaumarchaea, which represent as much as 20% of prokaryotic biomass in the open ocean, have been linked to environmentally relevant biogeochemical processes, such as ammonia oxidation (nitrification) and inorganic carbon fixation. We have used culture-independent methods to study this group because current cultivation limitations have proved a hindrance in studying these organisms. From a metagenomic data set obtained from surface waters from the Gulf of Maine, we have identified 36,111 sequence reads (containing 30 Mbp) likely derived from environmental planktonic Thaumarchaea.
View Article and Find Full Text PDFMariprofundus ferrooxydans PV-1 has provided the first genome of the recently discovered Zetaproteobacteria subdivision. Genome analysis reveals a complete TCA cycle, the ability to fix CO(2), carbon-storage proteins and a sugar phosphotransferase system (PTS). The latter could facilitate the transport of carbohydrates across the cell membrane and possibly aid in stalk formation, a matrix composed of exopolymers and/or exopolysaccharides, which is used to store oxidized iron minerals outside the cell.
View Article and Find Full Text PDFThe surface layer of the oceans and other aquatic environments contains many bacteria that range in activity, from dormant cells to those with high rates of metabolism. However, little experimental evidence exists about the activity of specific bacterial taxa, especially rare ones. Here we explore the relationship between abundance and activity by documenting changes in abundance over time and by examining the ratio of 16S rRNA to rRNA genes (rDNA) of individual bacterial taxa.
View Article and Find Full Text PDFPhototrophic microbial mat communities from 60°C and 65°C regions in the effluent channels of Mushroom and Octopus Springs (Yellowstone National Park, WY, USA) were investigated by shotgun metagenomic sequencing. Analyses of assembled metagenomic sequences resolved six dominant chlorophototrophic populations and permitted the discovery and characterization of undescribed but predominant community members and their physiological potential. Linkage of phylogenetic marker genes and functional genes showed novel chlorophototrophic bacteria belonging to uncharacterized lineages within the order Chlorobiales and within the Kingdom Chloroflexi.
View Article and Find Full Text PDFInsertion sequences (ISs) are simple mobile genetic elements capable of relocating within a genome. Through this transposition activity, they are known to create mutations which are mostly deleterious to the cell, although occasionally they are beneficial. Two closely related isolates of thermophilic Synechococcus species from hot spring microbial mats are known to harbor a large number of diverse ISs.
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