Source Themes

Carbon in the deep biosphere: forms, fates, and biogeochemical cycling

This chapter is in *Deep Carbon: Past to Present*, Beth N. Orcutt, Isabelle Daniel, and Rajdeep Gupta, eds, to be published by Cambrdige University Press in October 2019.

Unaligned Sequence Similarity Search Using Deep Learning

Gene annotation has traditionally required direct comparison of DNA sequences between an unknown gene and a database of known ones using string comparison methods. However, these methods do not provide useful information when a gene does not have a …

Kinetics and identities of extracellular peptidases in subsurface sediments of the White Oak River Estuary, NC

Widely used microbial taxonomies, such as the NCBI taxonomy, are based on a combination of sequence homology among conserved genes and historically accepted taxonomies, which were developed based on observable traits such as morphology and …

Polysaccharide hydrolysis in the presence of oil and dispersants: Insights into potential degradation pathways of exopolymeric substances (EPS) from oil-degrading bacteria

Oceanic oil-degrading bacteria produce copious amounts of exopolymeric substances (EPS) that facilitate their access to oil. The fate of EPS in the water column is in part determined by activities of heterotrophic microbes capable of utilizing EPS …

Theoretical and Simulation-Based Investigation of the Relationship between Sequencing Effort, Microbial Community Richness, and Diversity in Binning Metagenome-Assembled Genomes

We applied theoretical and simulation-based approaches to characterize how microbial community structure influences the amount of sequencing effort to reconstruct metagenomes that are assembled from short-read sequences. First, a coupon collector …

High proportions of bacteria and archaea across most biomes remain uncultured

A recent paper by Martiny argues that “high proportions” of bacteria in diverse Earth environments have been cultured. Here we reanalyze a portion of the data in that paper, and argue that the conclusion is based on several technical errors, most …

Kinetics and Identities of Extracellular Peptidases in Subsurface Sediments of the White Oak River Estuary, North Carolina

Anoxic subsurface sediments contain communities of heterotrophic microorganisms that metabolize organic carbon at extraordinarily slow rates. In order to assess the mechanisms by which subsurface microorganisms access detrital sedimentary organic …

Uncultured microbial phyla suggest mechanisms for multi-thousand-year subsistence in Baltic Sea sediments

Energy-starved microbes in deep marine sediments subsist at near-zero growth for thousands of years, yet the mechanisms for their subsistence are unknown because no model strains have been cultivated from most of these groups. We investigated Baltic …

Characterization of the Interactive Effects of Labile and Recalcitrant Organic Matter on Microbial Growth and Metabolism

Geochemical models typically represent organic matter (OM) as consisting of multiple, independent pools of compounds, each accessed by microorganisms at different rates. However, recent findings indicate that organic compounds can interact within …

Editorial: Extracellular Enzymes in Aquatic Environments: Exploring the Link Between Genomic Potential and Biogeochemical Consequences