The marine ecosystem of Kongsfjorden, Svalbard

Hop, Haakon; Pearson, T.H.; Hegseth, Else Nøst; Kovacs, Kit M.; Wiencke, Christian; Kwaśniewski, Sławomir; Eiane, Ketil; Mehlum, Fridtjof; Gulliksen, Bjørn; Włodarska‐Kowalczuk, Maria; Lydersen, Christian; Węsławski, Jan Marcin; Cochrane, Sabine; Gabrielsen, Geir Wing; Leakey, Raymond J.G.; Lønne, Ole Jørgen; Zajączkowski, Marek; Falk‐Petersen, Stig; Kendall, Michael A.; Wängberg, Sten-Åke; Bischof, Kai; Voronkov, Andrey; Kovaltchouk, Nikolaj A.; Wiktor, Józef; Poltermann, Michael; Prisco, Guido di; Papucci, C.; Gerland, Sebastian

doi:10.3402/polar.v21i1.6480

Cited by 106 publications

(162 citation statements)

References 168 publications

(209 reference statements)

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“…This suggests that pullulan is a relevant (i.e., microbially accessible) substrate in the marshes surrounding the Chesapeake Bay, and in the sediments of the bay, but not in the water column. A similar mismatch has been observed in the case of fucoidin, which is typically hydrolyzed in Svalbard sediment but not in fjord waters (Arnosti 2004), despite the presence of fucoidin-producing Fucus species in Svalbard fjords (Hop et al 2002).…”

Section: Discussionsupporting

confidence: 68%

Dynamics of dissolved carbohydrates in the Chesapeake Bay: Insights from enzyme activities, concentrations, and microbial metabolism

Steen

Hamdan

Arnosti

2008

Limnology & Oceanography

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The interactions between heterotrophic microbes and high-molecular-weight (HMW) dissolved organic carbon in estuaries are complex and poorly understood. This study examined the coupling between hydrolysis of HMW carbohydrates (polysaccharides) and uptake of monosaccharides by bacterioplankton along a salinity gradient in the Chesapeake Bay water column and nearby coastal waters in order to evaluate the potential importance of polysaccharides as a carbon source for the estuarine microbial loop. We measured the rates of enzymatic hydrolysis of six polysaccharides (arabinogalactan, chondroitin sulfate, fucoidin, laminarin, pullulan, and xylan) as well as total carbohydrate and monosaccharide concentrations, bacterioplankton abundance, and monosaccharide assimilation rates. Enzymatic hydrolysis rates were sufficiently rapid to produce on a daily basis 40-62% of the monosaccharides present in Chesapeake Bay surface waters but a lower percentage (23%) of monosaccharides present in surface water on the continental shelf. Rates of both monosaccharide assimilation and polysaccharide hydrolysis were markedly lower on the continental shelf than in the Chesapeake Bay. These measurements suggest that at the time of sampling, polysaccharides in the Chesapeake Bay were rapidly recycled, while rates of cycling were considerably slower on the nearby continental shelf. In contrast to the apparently rapid turnover of bulk polysaccharides, hydrolysis of two polysaccharides, pullulan and chondroitin sulfate, was essentially undetectable, implying that those substrates would be unavailable to the microbial communities sampled on a timescale of 10 d.

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Section: Discussionsupporting

confidence: 68%

Dynamics of dissolved carbohydrates in the Chesapeake Bay: Insights from enzyme activities, concentrations, and microbial metabolism

Steen

Hamdan

Arnosti

2008

Limnology & Oceanography

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“…Nutrient and redox gradients established by microbial activities in such sediments can be disturbed by tidal activity, fluctuating organic input and bioturbation. In particular, bioturbation by worms and by walruses feeding on mussels causes intensive mixing of the Svalbard sediment and oxygen penetration down to about 20 cm depth (Hop et al, 2002;Finke, 2003). To survive sudden oxygen exposure until aerobic members of the microbial community have consumed the oxygen, D. psychrophila is likely to depend on its own oxygen detoxification systems.…”

Section: Resultsmentioning

confidence: 99%

The genome of Desulfotalea psychrophila, a sulfate‐reducing bacterium from permanently cold Arctic sediments

Rabus

Ruepp²,

Frickey

et al. 2004

Environmental Microbiology

186

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Desulfotalea psychrophila is a marine sulfate-reducing delta-proteobacterium that is able to grow at in situ temperatures below 0 degrees C. As abundant members of the microbial community in permanently cold marine sediments, D. psychrophila-like bacteria contribute to the global cycles of carbon and sulfur. Here, we describe the genome sequence of D. psychrophila strain LSv54, which consists of a 3 523 383 bp circular chromosome with 3118 predicted genes and two plasmids of 121 586 bp and 14 663 bp. Analysis of the genome gave insight into the metabolic properties of the organism, e.g. the presence of TRAP-T systems as a major route for the uptake of C(4)-dicarboxylates, the unexpected presence of genes from the TCA cycle, a TAT secretion system, the lack of a beta-oxidation complex and typical Desulfovibrio cytochromes, such as c(553), c(3) and ncc. D. psychrophila encodes more than 30 two-component regulatory systems, including a new Ntr subcluster of hybrid kinases, nine putative cold shock proteins and nine potentially cold shock-inducible proteins. A comparison of D. psychrophila's genome features with those of the only other published genome from a sulfate reducer, the hyperthermophilic archaeon Archaeoglobus fulgidus, revealed many striking differences, but only a few shared features.

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“…This results in shallowing of the euphotic zone from > 30 m at the mouth of Kongsfjorden to < 1 m in its inner basin (Svendsen et al, 2002). Complex hydrological conditions create steep gradients of salinity, temperature and light availability along the fjord (Hop et al, 2002). These factors likely affect the abundance and distribution of PFs in the fjord (Piwosz et al, 2009).…”

Section: Introductionmentioning

confidence: 99%

Distribution of small phytoflagellates along an Arctic fjord transect

Piwosz

Spich

Całkiewicz

et al. 2015

Environmental Microbiology

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Phytoflagellates <10 μm substantially contribute to the abundance, biomass and primary production in polar waters, but information on the distribution of specific groups is scarce. We applied catalysed reporter deposition-fluorescence in situ hybridization to investigate the distribution of total phytoflagellates and of eight specific groups along a 100 km transect west off Kongsfjorden (Spitsbergen) from 29 to 31 July 2010. Phytoflagellates contributed to >75% of the depth-integrated abundance and biomass of total eukaryotes <10 μm at all stations. Their depth-integrated abundance and biomass decreased along the transect from 1.5 × 10(12) cells m(-2) (6.6 × 10(12) pgC m(-2) ) at the outermost station to 1.7 × 10(10) cells m(-2) (4.7 × 10(10) pgC m(-2) ) at the innermost station. Chlorophytes contributed to the total abundance of phytoflagellates with a range from 13% to 87% (0.7-30.5 × 10(3) cells ml(-1) ), and predominated in open waters. The contribution of haptophytes was < 1-38% (10-4500 cells ml(-1) ). The other groups represented <10%. The temperature and salinity positively correlated with the total abundance of phytoflagellates, chlorophytes, haptophytes, bolidophytes and pelagophytes. Cryptophytes, pedinellids and pavlovophytes were negatively associated with the nutrient concentrations. The community composition of phytoflagellates changed along the transect, which could have implications on food web dynamics and biogeochemical cycles between the open ocean environment and Kongsfjorden investigated here.

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The marine ecosystem of Kongsfjorden, Svalbard

Cited by 106 publications

References 168 publications

Dynamics of dissolved carbohydrates in the Chesapeake Bay: Insights from enzyme activities, concentrations, and microbial metabolism

Dynamics of dissolved carbohydrates in the Chesapeake Bay: Insights from enzyme activities, concentrations, and microbial metabolism

The genome of Desulfotalea psychrophila, a sulfate‐reducing bacterium from permanently cold Arctic sediments

Distribution of small phytoflagellates along an Arctic fjord transect

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