Publications by authors named "Colleen T E Kellogg"

Deep6 is a deep learning model that classifies metatranscriptomic sequences as short as 250 nucleotides into prokaryotes, eukaryotes, or one of the four viral realms, using a reference-independent and alignment-free approach. Average accuracies range from 0.87 to 0.

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Ocean acidification upwelling events and the resulting lowered aragonite saturation state of seawater have been linked to high mortality of marine bivalve larvae in hatcheries. Major oyster seed producers along North America's west coast have mitigated impacts via seawater pH buffering (e.g.

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Recent studies on marine heat waves describe water temperature anomalies causing changes in food web structure, bloom dynamics, biodiversity loss, and increased plant and animal mortality. However, little information is available on how water temperature anomalies impact prokaryotes (bacteria and archaea) inhabiting ocean waters. This is a nontrivial omission given their integral roles in driving major biogeochemical fluxes that influence ocean productivity and the climate system.

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Article Synopsis
  • Arctic lagoons in the Alaska Beaufort Sea experience extreme seasonal changes, with nine months of ice followed by a brief period of thaw that introduces a surge of freshwater and nutrients.
  • Prokaryotic communities in these lagoons are significant for linking these seasonal nutrients to the food web, but their genomic responses to these changes are not well documented.
  • The study collected water samples across three seasons (winter, spring, summer) to analyze how microbial gene abundances vary, revealing that spring had the highest nutrient-related gene expression due to thawing, while winter showed energy limitations and reliance on certain metabolic processes.
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Article Synopsis
  • Microbial communities in the coastal Arctic Ocean are influenced by seasonal changes in sea ice and freshwater, which affect the availability of organic matter and nutrients, particularly in lagoons along the Beaufort Sea coast.
  • Research utilizing 16S and 18S rRNA gene sequences revealed significant seasonal shifts in planktonic communities, with winter communities centered on bacterial and protistan parasites and spring transitioning to diatom proliferation, ultimately leading to a diverse summer community with mixotrophic and dinoflagellate organisms.
  • Co-occurrence networks indicated distinct interactions among microbial taxa across seasons, highlighting that winter networks were shaped by parasite relationships, while spring featured extensive bacteria-bacteria connections, and summer interactions were more complex.
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The Pacific coastal temperate rainforest (PCTR) is a global hot-spot for carbon cycling and export. Yet the influence of microorganisms on carbon cycling processes in PCTR soil is poorly characterized. We developed and tested a conceptual model of seasonal microbial carbon cycling in PCTR soil through integration of geochemistry, micro-meteorology, and eukaryotic and prokaryotic ribosomal amplicon (rRNA) sequencing from 216 soil DNA and RNA libraries.

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Although previous studies, mostly based on microscopy analyses of a few groups of protists, have suggested that protists are abundant and diverse in litter and moss habitats, the overall diversity of moss and litter associated protists remains elusive. Here, high-throughput environmental sequencing was used to characterize the diversity and community structure of litter- and moss-associated protists along a gradient of soil drainage and forest primary productivity in a temperate rainforest in British Columbia. We identified 3262 distinct protist OTUs from 36 sites.

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Warming at nearly twice the global rate, higher than average air temperatures are the new 'normal' for Arctic ecosystems. This rise in temperature has triggered hydrological and geochemical changes that increasingly release carbon-rich water into the coastal ocean via increased riverine discharge, coastal erosion, and the thawing of the semi-permanent permafrost ubiquitous in the region. To determine the biogeochemical impacts of terrestrially derived dissolved organic matter (tDOM) on marine ecosystems we compared the nutrient stocks and bacterial communities present under ice-covered and ice-free conditions, assessed the lability of Arctic tDOM to coastal microbial communities from the Chukchi Sea, and identified bacterial taxa that respond to rapid increases in tDOM.

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Microbial enzymatic hydrolysis of marine-derived particulate organic carbon (POC) can be a dominant mechanism for attenuating carbon flux in cold Arctic waters during spring and summer. Whether this mechanism depends on composition of associated microbial communities and extends into other seasons is not known. Bacterial community composition (BCC) and extracellular enzyme activity (EEA, for leucine aminopeptidases, glucosidases and chitobiases) were measured on small suspended particles and potentially sinking aggregates collected during fall from waters of the biologically productive North Water and river-impacted Beaufort Sea.

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