scholarly journals Dissolved organic matter assimilation by heterotrophic bacterial groups in the western Arctic Ocean

2007 ◽  
Vol 50 ◽  
pp. 39-49 ◽  
Author(s):  
H Elifantz ◽  
AI Dittel ◽  
MT Cottrell ◽  
DL Kirchman
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Arctic Ocean ◽  
Western Arctic Ocean ◽  
Western Arctic ◽  
Bacterial Groups

scholarly journals Dissolved organic matter composition and bioavailability reflect ecosystem productivity in the Western Arctic Ocean

2012 ◽  
Vol 9 (7) ◽  
pp. 9571-9601 ◽  
Author(s):  
Y. Shen ◽  
C. G. Fichot ◽  
R. Benner
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Arctic Ocean ◽  
Surface Waters ◽  
Microbial Growth ◽  
Chukchi Sea ◽  
Ecosystem Productivity ◽  
Western Arctic Ocean ◽  
Western Arctic ◽  
High Yields

Abstract. Dissolved organic carbon (DOC) and total dissolved amino acids (TDAA) were measured in high (Chukchi Sea) and low (Beaufort Sea) productivity regions of the Western Arctic Ocean to investigate the composition and bioavailability of dissolved organic matter (DOM). Concentrations and DOC-normalized yields of TDAA in Chukchi surface waters were relatively high, indicating an accumulation of bioavailable DOM. High yields of TDAA were also observed in the upper halocline of slope and basin waters, indicating off-shelf transport of bioavailable DOM from the Chukchi Sea. In contrast, concentrations and yields of TDAA in Beaufort surface waters were relatively low, indicting DOM was of limited bioavailability. Yields of TDAA in the upper halocline of slope and basin waters were also low, suggesting the Beaufort is not a major source of bioavailable DOM to slope and basin waters. In shelf waters of both systems, elevated concentrations and yields of TDAA were often observed in waters with higher chlorophyll concentrations and productivity. Surface concentrations of DOC were similar (p > 0.05) in the two systems despite the contrasting productivity, but concentrations and yields of TDAA were significantly higher (p < 0.0001) in the Chukchi than in the Beaufort. Unlike bulk DOC, TDAA concentrations and yields reflect ecosystem productivity in the Western Arctic. The occurrence of elevated bioavailable DOM concentrations in the Chukchi implies an uncoupling between the biological production and utilization of DOM and has important implications for sustaining heterotrophic microbial growth and diversity in oligotrophic waters of the Central Arctic basins.

scholarly journals Dissolved organic matter composition and bioavailability reflect ecosystem productivity in the Western Arctic Ocean

2012 ◽  
Vol 9 (12) ◽  
pp. 4993-5005 ◽  
Author(s):  
Y. Shen ◽  
C. G. Fichot ◽  
R. Benner
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Arctic Ocean ◽  
Surface Waters ◽  
Microbial Growth ◽  
Chukchi Sea ◽  
Ecosystem Productivity ◽  
Western Arctic Ocean ◽  
Western Arctic ◽  
High Concentrations

Abstract. Dissolved organic carbon (DOC) and total dissolved amino acids (TDAA) were measured in high (Chukchi Sea) and low (Beaufort Sea) productivity regions of the western Arctic Ocean to investigate the composition and bioavailability of dissolved organic matter (DOM). Concentrations and DOC-normalized yields of TDAA in Chukchi surface waters were relatively high, indicating an accumulation of bioavailable DOM. High concentrations and yields of TDAA were also observed in the upper halocline of slope and basin waters, indicating off-shelf transport of bioavailable DOM from the Chukchi Sea. In contrast, concentrations and yields of TDAA in Beaufort surface waters were relatively low, indicting DOM was of limited bioavailability. Concentrations and yields of TDAA in the upper halocline of slope and basin waters were also low, suggesting the Beaufort is not a major source of bioavailable DOM to slope and basin waters. In shelf waters of both systems, elevated concentrations and yields of TDAA were often observed in waters with higher chlorophyll concentrations and productivity. Surface concentrations of DOC were similar (p > 0.05) in the two systems despite the contrasting productivity, but concentrations and yields of TDAA were significantly higher (p < 0.0001) in the Chukchi than in the Beaufort. Unlike bulk DOC, TDAA concentrations and yields reflect ecosystem productivity in the western Arctic. The occurrence of elevated bioavailable DOM concentrations in the Chukchi Sea implies an uncoupling between the biological production and utilization of DOM and has important implications for sustaining heterotrophic microbial growth and diversity in oligotrophic waters of the central Arctic basins.

scholarly journals Metaproteomics reveal that rapid perturbations in organic matter prioritize functional restructuring over taxonomy in western Arctic Ocean microbiomes

2019 ◽  
Vol 14 (1) ◽  
pp. 39-52 ◽  
Author(s):  
Molly P. Mikan ◽  
H. Rodger Harvey ◽  
Emma Timmins-Schiffman ◽  
Michael Riffle ◽  
Damon H. May ◽  
...  
Keyword(s):  
Organic Matter ◽  
Arctic Ocean ◽  
Western Arctic Ocean ◽  
Western Arctic

scholarly journals Abundance and Single-Cell Activity of Heterotrophic Bacterial Groups in the Western Arctic Ocean in Summer and Winter

2012 ◽  
Vol 78 (7) ◽  
pp. 2402-2409 ◽  
Author(s):  
Mrinalini P. Nikrad ◽  
M. T. Cottrell ◽  
D. L. Kirchman
Keyword(s):  
Amino Acid ◽  
Arctic Ocean ◽  
Heterotrophic Bacteria ◽  
Cell Activity ◽  
Organic Substrates ◽  
Content Type ◽  
Western Arctic Ocean ◽  
Western Arctic ◽  
Bacterial Groups

ABSTRACTEnvironmental conditions in the western Arctic Ocean range from constant light and nutrient depletion in summer to complete darkness and sea ice cover in winter. This seasonal environmental variation is likely to have an effect on the use of dissolved organic matter (DOM) by heterotrophic bacteria in surface water. However, this effect is not well studied and we know little about the activity of specific bacterial clades in the surface oceans. The use of DOM by three bacterial subgroups in both winter and summer was examined by microautoradiography combined with fluorescencein situhybridization. We found selective use of substrates by these groups, although the abundances of Ant4D3 (AntarcticGammaproteobacteria),Polaribacter(Bacteroidetes), and SAR11 (Alphaproteobacteria) were not different between summer and winter in the Beaufort and Chukchi Seas. The number of cells taking up glucose within all three bacterial groups decreased significantly from summer to winter, while the percentage of cells using leucine did not show a clear pattern between seasons. The uptake of the amino acid mix increased substantially from summer to winter by the Ant4D3 group, although such a large increase in uptake was not seen for the other two groups. Use of glucose by bacteria, but not use of leucine or the amino acid mix, related strongly to inorganic nutrients, chlorophylla, and other environmental factors. Our results suggest a switch in use of dissolved organic substrates from summer to winter and that the three phylogenetic subgroups examined fill different niches in DOM use in the two seasons.

scholarly journals Diversity, abundance, and biomass production of bacterial groups in the western Arctic Ocean

2007 ◽  
Vol 47 ◽  
pp. 45-55 ◽  
Author(s):  
RR Malmstrom ◽  
TRA Straza ◽  
MT Cottrell ◽  
DL Kirchman
Keyword(s):  
Arctic Ocean ◽  
Biomass Production ◽  
Western Arctic Ocean ◽  
Western Arctic ◽  
Bacterial Groups
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