Oceanic carbon cycling plays a major role in determining global atmospheric CO₂. A better understanding of dissolved organic matter and its constituents in the water column and how it affects marine carbon cycling is sought after. This study successfully measured osmolytes, low molecular zwitterionic compounds derived from amino acids, in...
Marine bacteria play vital roles in every niche of the ocean, from small-scale symbioses to large-scale productivity and the regulation of Earth’s climate. Recent advances in molecular tools now allow us to probe the genetic potential of entire microbial communities. The next step is linking these diverse communities to the...
Historically, the difficulty of obtaining pure cultures of abundant marine
microbial plankton has an obstacle to reconstructing the underlying
mechanisms of biogeochemistry in the ocean. While a number of dominant
marine species from the ocean surface have been cultured, the dominant
microbial plankton of the dark ocean proved far more...
Over 100 monthly bacterioplankton DNA samples, from each of the surface and 200 m depths at the Bermuda Atlantic Time-series Study (BATS) site, were analyzed for community assembly processes. Correlation networks, filtered for potential autocorrelation artifacts, were constructed for each depth. Network characteristics for the two depths were remarkably similar...
SAR11 Alphaproteobacteria are the most abundant aerobic chemoheterotrophs in ocean surface waters. Previous studies have indicated SAR11 cells play an important role in marine carbon cycling and consume up to half of some common dissolved organic compounds, such as amino acids. During sequencing of the first SAR11 genome, genes for...
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2. One Carbon Metabolism in SAR11 Pelagic MarineBacteria
Members of the SAR11 clade of heterotrophic α-proteobacteria are ubiquitous and abundant in the world's oceans where they are thought to play a pivotal role in the global carbon cycle. The first SAR11 bacterium cultivated in vitro, 'Candidatus Pelagibacter ubique' HTCC1062 (Ca. P. ubique), was isolated by dilution into sterile...
Biological di-nitrogen (N₂) fixation is a key process in open-ocean ecosystems, where the new nitrogen (N) provided by marine diazotrophs can support a large fraction of primary productivity and carbon (C) drawdown. Recent laboratory studies have shown that elevated pCO₂ enhances the rate of N₂ fixation by select laboratory isolates...
Batch cultures of Candidatus Pelagibacter ubique were grown under iron-, organosulfur-, and nitrogen-limiting conditions to understand how this ubiquitous marine bacterium responds to and interacts with environments where growth is limited by the availability of these nutrients. Global gene expression was monitored using microarrays and quantitative mass spectrometry to observe...
Proteins are the metabolic machines of the cell and as such, the study of proteins could illuminate the dominant biological activities that are occurring within cells and reveal how an organism interacts with its environment. Here, we used proteomic techniques to study the abundant marine bacterium SAR11 both as an...
Oceanic crust covers nearly 70% of the Earth's surface, of which, the upper,
sediment layer is estimated to harbor substantial microbial biomass. Marine crust;
however, extends several kilometers beyond this surficial layer, and includes the
basalt and gabbro layers. In particular, the basalt layer has high permeabilities which
allows for...
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Figure 2.1. Overview of the Bacteria and Archaea associated with marine basalts