Characterization of extracellular polymers of Phaeocystis globosa and P. antarctica

Solomon, Caroline; Lessard, Evelyn J.; Keil, Richard G.; Foy, Michael S.

doi:10.3354/meps250081

Cited by 32 publications

(27 citation statements)

References 41 publications

(62 reference statements)

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“…Qualitative staining of the colony matrix indicated the absence of lipophilic compounds and chitin, but the presence of amino groups (Hamm et al 1999). Matrix-assisted laser desorption/ionization (MALDI) analysis showed that N was not proteineous, but probably present in aminosugars (Solomon et al 2003). The presence of the aminosugar sialic acid was confirmed by aminolabeling .…”

Section: Mucopolysaccharidesmentioning

confidence: 85%

“…Since all studies used filtration techniques applying pressure, it is most likely that the DOM also contained mucopolysaccharides. The overall C/N ratio of the DOM is low, around 7 (Biddanda and Benner 1997; Solomon et al 2003). Similar to mucopolysaccharides, extracolonial polymers self assemble in hydrated polymer gels on a time scale of approximately two days (Solomon et al 2003).…”

Section: Contribution Of Mucopolysaccharides-c To Pocmentioning

confidence: 99%

“…The three main mechanisms of DOM production are: (1) release Solomon et al (2003) after cell lysis, e.g., as a result of viral infection, zooplankton sloppy feeding and egestion, (2) bacterial cleavage of exopolysaccharides (Smith et al 1995), or (3) direct release as a physiological process of intact cells (reviewed by Nagata 2000). Two physiological mechanisms of DOM production have been advocated: a passive diffusion of small metabolites through the cell membrane (Bjørnsen 1988) and an overflow mechanism whereby excess photosynthetic products are actively released when the C fixation rate exceeds the rate of macromolecular production (Fogg 1983).…”

Section: Mechanisms Of Dom Release During a Phaeocystis Bloommentioning

confidence: 99%

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The carbohydrates of Phaeocystis and their degradation in the microbial food web

2007

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The ubiquity and high productivity associated with blooms of colonial Phaeocystis makes it an important contributor to the global carbon cycle. During blooms organic matter that is rich in carbohydrates is produced. We distinguish five different pools of carbohydrates produced by Phaeocystis. Like all plants and algal cells, both solitary and colonial cells produce (1) structural carbohydrates, (hetero) polysaccharides that are mainly part of the cell wall, (2) mono-and oligosaccharides, which are present as intermediates in the synthesis and catabolism of cell components, and (3) intracellular storage glucan. Colonial cells of Phaeocystis excrete (4) mucopolysaccharides, heteropolysaccharides that are the main constituent of the mucous colony matrix and (5) dissolved organic matter (DOM) rich in carbohydrates, which is mainly excreted by colonial cells. In this review the characteristics of these pools are discussed and quantitative data are summarized. During the exponential growth phase, the ratio of carbohydrate-carbon (C) to particulate organic carbon (POC) is approximately 0.1. When nutrients are limited, Phaeocystis blooms reach a stationary growth phase, during which excess energy is stored as carbohydrates. This so-called overflow metabolism increases the ratio of carbohydrate-C to POC to 0.4-0.6 during the stationary phase, leading to an increase in the C/N and C/P ratios of Phaeocystis organic matter. Overflow metabolism can be channeled towards both glucan and mucopolysaccharides. Summarizing the available data reveals that during the stationary phase of a bloom glucan contributes 0-51% to POC, whereas mucopolysaccharides contribute 5-60%. At the end of a bloom, lysis of Phaeocystis cells and deterioration of colonies leads to a massive release of DOM rich in glucan and mucopolysaccharides. Laboratory studies have revealed that this organic matter is potentially readily degradable by heterotrophic bacteria. However, observations in the field of accumulation of DOM and foam indicate that microbial degradation is hampered. The high C/N and C/P ratios of Phaeocystis organic matter may lead to nutrient limitation of microbial degradation, thereby prolonging degradation times. Over time polysaccharides tend to self-assemble into hydrogels. This may have a profound effect on carbon cycling, since hydrogels provide a vehicle to move DOM up the size spectrum to sizes subject to sedimentation. In

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Section: Mucopolysaccharidesmentioning

confidence: 85%

Section: Contribution Of Mucopolysaccharides-c To Pocmentioning

confidence: 99%

Section: Mechanisms Of Dom Release During a Phaeocystis Bloommentioning

confidence: 99%

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The carbohydrates of Phaeocystis and their degradation in the microbial food web

2007

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“…In the present study, we assessed the abundance and the contribution of major bacterial groups to DOM assimilation. We examined the assimilation of amino acids, glucose, protein, and EPS because of the biogeochemical importance of these compounds in all aquatic environments, including cold ones (Kirchman et al 2001, Krembs et al 2002, Solomon et al 2003. The concentrations of glucose and amino acids vary regionally in the Arctic Ocean, and both compounds have high turnover rates, but amino acid uptake has exceeded glucose uptake in the Arctic waters examined to date (Rich et al 1997, Meon & Amon 2004.…”

mentioning

confidence: 99%

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

Elifantz¹,

Dittel²,

Cottrell³

et al. 2007

Aquat. Microb. Ecol.

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Abundance of the major bacterial groups and dissolved organic matter (DOM) assimilation in the western Arctic Ocean were determined using fluorescence in situ hybridization (FISH) and microautoradiography combined with FISH (Micro-FISH). Cytophaga-like bacteria (25 to 65%) and Alphaproteobacteria (17 to 40%) were the dominant bacterial groups, followed by Gammaproteobacteria (10 to 30%). In contrast, Betaproteobacteria and Actinobacteria were never abundant. While the distribution of Alphaproteobacteria was relatively uniform along a transect from the shelf to the basin, Cytophaga-like bacteria were more abundant on the shelf and shelf-break. Similarly, the contribution to DOM assimilation by Cytophaga-like bacteria was highest on the shelf and lowest in the basin. In contrast, Alphaproteobacteria contributed the most to DOM assimilation at the slope. About 80 to 99% of the variation in DOM assimilation was explained by bacterial group abundance. As a whole, the prokaryotic community was most active in assimilating free amino acids (50 to 60%), followed by diatom-derived extracellular polymers (30 to 40%) and protein (20 to 30%). In contrast, relatively few cells assimilated glucose (10 to 20%). This study revealed substantial variation in the abundance of major bacterial groups among the Arctic regions and in the assimilation of DOM components by these bacteria. KEY WORDS: DOM assimilation · Arctic Ocean · Micro-FISH · Heterotrophic bacteria Resale or republication not permitted without written consent of the publisherAquat Microb Ecol 50: [39][40][41][42][43][44][45][46][47][48][49] 2007 overestimate the true activity. In the western Arctic Ocean, up to 60 and 45% of bacteria and archaea, respectively, assimilated various DOM compounds ). Other data suggest that up to 84% of total prokaryotes are active in reducing 5-cyano-2, 3-ditoyl tetrazolium chloride in the western Arctic Ocean (Yager et al. 2001, Huston & Deming 2002. These estimates are consistent with studies showing that a high fraction of bacteria (67 to 99%) and archaea (5 to 25%) are detected by fluorescence in situ hybridization (FISH) in Arctic water (Wells & Deming 2003, Garneau et al. 2006, Wells et al. 2006.Several bacterial groups are present in cold environments such as the Arctic Ocean. These groups include Bacteroidetes and several subdivisions of the Proteobacteria (Ferrari & Hollibaugh 1999, Bano & Hollibaugh 2002, Bowman et al. 2003. In surface waters of the Canadian Archipelago, the Cytophaga-Flavobacterium cluster makes up 9 to 41% of total cells (Wells & Deming 2003). In the shelf and shelf-break of the Beaufort Sea, Alphaproteobacteria dominate the bacterial community, followed by Gammaproteobacteria and Cytophaga-like bacteria (Garneau et al. 2006). These 3 phylogenetic groups are also the dominant bacterial groups in Arctic pack ice (Brinkmeyer et al. 2003). In other cold water environments, such as the North Sea and the Southern Ocean, Cytophaga-like bacteria are found to dominate the community, followed by Alphaprot...

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“…In the current work however, early algal concentrations are all set to a single low value. Phaeocystis is included because its life history is specialized with regard to the organics -it is known for release of organosulfur compounds, polysaccharides and amino sugars [118,[131][132]. Polymer chemistry allows this unique organism to become effectively multicellular by forming colonies.…”

Section: Appendix B: Parametersmentioning

confidence: 99%

Strategies for the Simulation of Sea Ice Organic Chemistry: Arctic Tests and Development

Elliott¹,

Jeffery²,

Hunke³

et al. 2017

Preprint

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Abstract:A numerical mechanism connecting ice algal ecodynamics with the buildup of organic macromolecules is tested within modeled pan-Arctic brine channels. The simulations take place offline in a reduced representation of sea ice geochemistry. Physical driver quantities derive from the global sea ice code CICE, including snow cover, thickness and internal temperature. The framework is averaged over ten boreal biogeographic zones. Computed nutrient-light-salt limited algal growth supports grazing, mortality and carbon flow. Vertical transport is diffusive but responds to pore structure. Simulated bottom layer chlorophyll maxima are reasonable, though delayed by about a month relative to observations due to uncertainties in snow variability. Upper level biota arise intermittently during flooding events. Macromolecular concentrations are tracked as proxy proteins, polysaccharides, lipids and refractory humics. The fresh biopolymers undergo succession and removal by bacteria. Baseline organics enter solely through cell disruption, so that the internal carbon content is initially biased low. By including exudation, agreement with dissolved organic or individual biopolymer data is achieved given strong release coupled to light intensity. Detrital carbon then reaches hundreds of micromolar, sufficient to support structural changes to the ice matrix.

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Characterization of extracellular polymers of Phaeocystis globosa and P. antarctica

Cited by 32 publications

References 41 publications

The carbohydrates of Phaeocystis and their degradation in the microbial food web

The carbohydrates of Phaeocystis and their degradation in the microbial food web

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

Strategies for the Simulation of Sea Ice Organic Chemistry: Arctic Tests and Development

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