High bicarbonate assimilation in the dark by Arctic bacteria

Alonso‐Sáez, Laura; Galand, Pierre E.; Casamayor, Emilio O.; Pedrós-Alió, Carlos; Bertilsson, Stefan

doi:10.1038/ismej.2010.69

Cited by 139 publications

(137 citation statements)

References 47 publications

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“…The nitrite-oxidizing genus Nitrospina has been observed in winter-only samples from both Antarctic (Grzymski et al, 2012) and Arctic (Alonso-Sáez et al, 2010) waters, as well as in temperate waters (El-Swais et al, 2015) and has also been correlated with amoA-containing Thaumarchaeota in Monterey Bay (Mincer et al, 2007). Whilst we recorded generally higher levels of all three taxa in winter surface and year-round deeper waters, active populations were still detected in surface waters in summer months, albeit at much lower levels.…”

Section: Discussionmentioning

confidence: 64%

Changes in Marine Prokaryote Composition with Season and Depth Over an Arctic Polar Year

et al. 2017

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As the global climate changes, the higher latitudes are seen to be warming significantly faster. It is likely that the Arctic biome will experience considerable shifts in ice melt season length, leading to changes in photoirradiance and in the freshwater inputs to the marine environment. The exchange of nutrients between Arctic surface and deep waters and their cycling throughout the water column is driven by seasonal change. The impacts, however, of the current global climate transition period on the biodiversity of the Arctic Ocean and its activity are not yet known. To determine seasonal variation in the microbial communities in the deep water column, samples were collected from a profile (1-1000 m depth) in the waters around the Svalbard archipelago throughout an annual cycle encompassing both the polar night and day. High-throughput sequencing of 16S rRNA gene amplicons was used to monitor prokaryote diversity. In epipelagic surface waters (<200 m depth), seasonal diversity varied significantly, with light and the corresponding annual phytoplankton bloom pattern being the primary drivers of change during the late spring and summer months. In the permanently dark mesopelagic ocean depths (>200 m), seasonality subsequently had much less effect on community composition. In summer, phytoplankton-associated Gammaproteobacteria and Flavobacteriia dominated surface waters, whilst in low light conditions (surface waters in winter months and deeper waters all year round), the Thaumarchaeota and Chloroflexi-type SAR202 predominated. Alpha-diversity generally increased in epipelagic waters as seasonal light availability decreased; OTU richness also consistently increased down through the water column, with the deepest darkest waters containing the greatest diversity. Beta-diversity analyses confirmed that seasonality and depth also primarily drove community composition. The relative abundance of the eleven predominant taxa showed significant changes in surface waters in summer months and varied with season depending on the phytoplankton bloom stage; corresponding populations in deeper waters however, remained relatively unchanged. Given the significance of the annual phytoplankton bloom pattern on prokaryote diversity in Arctic waters, any changes to bloom dynamics resulting from accelerated global warming will likely have major impacts on surface marine microbial communities, those impacts inevitably trickling down into deeper waters.

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Section: Discussionmentioning

confidence: 64%

Changes in Marine Prokaryote Composition with Season and Depth Over an Arctic Polar Year

et al. 2017

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“…Carnivorous and detritus feeding by zooplankton could also have supplied labile dissolved compounds to the bacteria prior to the spring primary production, as indicated by the significant correlation between bacterial production and zooplankton production (Forest et al 2011). In addition, a recent study showed that other phylogenetically diverse psychrophylic strains of arctic bacteria are able to directly assimilate CO 2 in dark and nutrient-deprived winter conditions (Alonso-Saez et al 2010) presumably from the exploitation of metabolic processes such as nitrification (Galand et al 2009b). This high flexibility in the use of labile to refractory organic compounds at a time of low and extremely variable food availability is certainly the key to the maintenance of an active microbial food web throughout winter.…”

Section: The Winter Microbial Food Webmentioning

confidence: 99%

Current state and trends in Canadian Arctic marine ecosystems: II. Heterotrophic food web, pelagic-benthic coupling, and biodiversity

et al. 2012

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As part of the Canadian contribution to the International Polar Year (IPY), several major international research programs have focused on offshore arctic marine ecosystems. The general goal of these projects was to improve our understanding of how the response of arctic marine ecosystems to climate warming will alter food web structure and ecosystem services provided to Northerners. At least four key findings from these projects relating to arctic heterotrophic food web, pelagic-benthic coupling and biodiversity have emerged: (1) Contrary to a long-standing paradigm of dormant ecosystems during the long arctic winter, major food web components showed relatively high level of winter activity, well before the spring release of ice algae and subsequent phytoplankton bloom. Such phenological plasticity among key secondary producers like zooplankton may thus narrow the risks of Climatic Change

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“…Although light-independent or dark CO 2 assimilation has been usually assumed to be insignificant in oxygenated marine waters, a recent work by Alonso-Sáez et al (2010) suggests that the global relevance of this process could have been underestimated. Those results show for the first time that high ambient CO 2 concentrations could stimulate CO 2 fixation rates by increasing the CO 2 flux into the cells.…”

Section: Abstract: Bacterial Metabolism · Flavobacteriaceae · Ocean mentioning

confidence: 99%

Response of two marine bacterial isolates to high CO<sub>2 concentration

Teira¹,

Fernández²,

Álvarez‐Salgado³

et al. 2012

Mar. Ecol. Prog. Ser.

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Experimental results related to the effects of ocean acidification on planktonic marine microbes are still rather inconsistent and occasionally contradictory. Moreover, laboratory or field experiments that address the effects of changes in CO 2 concentrations on heterotrophic microbes are very scarce, despite the major role of these organisms in the marine carbon cycle. We tested the direct effect of an elevated CO 2 concentration (1000 ppmv) on the biomass and metabolic rates (leucine incorporation, CO 2 fixation and respiration) of 2 isolates belonging to 2 relevant marine bacterial families, Rhodobacteraceae (strain MED165) and Flavobacteriaceae (strain MED217). Our results demonstrate that, contrary to some expectations, high p CO 2 did not negatively affect bacterial growth but increased growth efficiency in the case of MED217. The elevated partial pressure of CO 2 (pCO 2 ) caused, in both cases, higher rates of CO 2 fixation in the dissolved fraction and, in the case of MED217, lower respiration rates. Both responses would tend to increase the pH of seawater acting as a negative feedback between elevated atmospheric CO 2 concentrations and ocean acidification. KEY WORDS: Bacterial metabolism · Flavobacteriaceae · Ocean acidification · RhodobacteraceaeResale or republication not permitted without written consent of the publisher Mar Ecol Prog Ser 453: 27-36, 2012 on marine bacterial isolates (Takeuchi et al. 1997, Labare et al. 2010. The latter studies found a decrease in the production and growth rates at pH < 7 -values far from the usual pH observed in ocean waters under present or future scenarios of elevated p CO 2 .Most microorganisms, particularly heterotrophic bacteria, are able to assimilate CO 2 as part of their metabolism through anaplerotic reactions (Roslev et al. 2004). Although light-independent or dark CO 2 assimilation has been usually assumed to be insignificant in oxygenated marine waters, a recent work by Alonso-Sáez et al. (2010) suggests that the global relevance of this process could have been underestimated. Those results show for the first time that high ambient CO 2 concentrations could stimulate CO 2 fixation rates by increasing the CO 2 flux into the cells.A comprehensive understanding of the effect of elevated CO 2 concentration on carbon cycling in the ocean requires the analysis of both production and respiration rates to provide a total carbon budget. However, to the best of our knowledge none of the published studies have simultaneously addressed the effect of CO 2 on BP and respiration, which are essential variables for bacterial growth efficiency (BGE) calculations. Allgaier et al. (2008) did find changes in bacterial taxonomic composition in response to high CO 2 concentrations, which suggest that the effects of elevated p CO 2 are likely to vary among species. Therefore, the aim of the present study was to test the direct effect of elevated CO 2 concentrations (1000 ppmv) on the biomass and metabolic rates (leucine incorporation, CO 2 fixation and respiration...

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High bicarbonate assimilation in the dark by Arctic bacteria

Cited by 139 publications

References 47 publications

Changes in Marine Prokaryote Composition with Season and Depth Over an Arctic Polar Year

Changes in Marine Prokaryote Composition with Season and Depth Over an Arctic Polar Year

Current state and trends in Canadian Arctic marine ecosystems: II. Heterotrophic food web, pelagic-benthic coupling, and biodiversity

Response of two marine bacterial isolates to high CO<sub>2 concentration

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