Dynamics of a Phaeocystis-dominated spring bloom in Belgian coastal waters. II. Bacterioplankton dynamics

Billen, Gilles; Fontigny, Anne

doi:10.3354/meps037249

Cited by 151 publications

(101 citation statements)

References 22 publications

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“…The availability of mucus as a growth substrate for heterotrophic bacteria is still unclear. Field observations suggest that although bacteria attach to colonies during late bloom stages (e.g., Thingstad and Billen 1994), at least part of the mucus is not degraded rapidly because mucus-derived foam accumulates after blooms (Eberlein et al 1985;Billen and Fontigny 1987;Lancelot et al 1987). The presence of mucus in sediments also raises the interesting question of whether the material can be degraded under anoxic conditions after it is buried in the sediment.…”

Section: Acknowledgmentsmentioning

confidence: 99%

Microbial breakdown of Phaeocystis mucopolysaccharides

Janse

Rijssel

Ottema

et al. 1999

Limnology & Oceanography

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Mucus from the microalga Phaeocystis was partially purified and used as the C source in various stable enrichment cultures wherein the mucus carbohydrates were degraded under oxic as well as anoxic conditions. The breakdown of mucopolysaccharides (initially at a rate of 50% in 11 d at 12ЊC) markedly slowed after about 15 d, leaving a fraction nondegraded. The carbohydrate composition of the residual fraction did not change during breakdown. It was shown that the incomplete degradation of mucopolysaccharides was not due to inherent resistance to breakdown in parts of the mucus carbohydrates but to the release of inhibitors produced during breakdown. The (potentially high) overall degradability of mucopolysaccharides has important consequences for the fate of C fixed by Phaeocystis. The balance between recycling of Phaeocystis biomass in surface waters and its accumulation, sedimentation, and burial in the sediment will greatly depend on factors such as nutrient availability, presence of inhibiting agents, and composition of the microbial community, rather than on structural impediments inhibiting mucopolysaccharide degradation.

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Section: Acknowledgmentsmentioning

confidence: 99%

Microbial breakdown of Phaeocystis mucopolysaccharides

Janse

Rijssel

Ottema

et al. 1999

Limnology & Oceanography

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“…LMW-DON such as DFAA released by protein hydrolysis (Billen and Fontigny, 1987) are readily assimilated by bacteria in aquatic systems (Hobbie et al, 1968) and can support up to~50% of bacterial production in the oceans (Kirchman, 2000).…”

Section: Introductionmentioning

confidence: 99%

Diverse, uncultivated bacteria and archaea underlying the cycling of dissolved protein in the ocean

et al. 2016

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Dissolved organic nitrogen (DON) supports a significant amount of heterotrophic production in the ocean. Yet, to date, the identity and diversity of microbial groups that transform DON are not well understood. To better understand the organisms responsible for transforming high molecular weight (HMW)-DON in the upper ocean, isotopically labeled protein extract from Micromonas pusilla, a eukaryotic member of the resident phytoplankton community, was added as substrate to euphotic zone water from the central California Current system. Carbon and nitrogen remineralization rates from the added proteins ranged from 0.002 to 0.35 μmol C l − 1 per day and 0.03 to 0.27 nmol N l − 1 per day. DNA stable-isotope probing (DNA-SIP) coupled with high-throughput sequencing of 16S rRNA genes linked the activity of 77 uncultivated freeliving and particle-associated bacterial and archaeal taxa to the utilization of Micromonas protein extract. The high-throughput DNA-SIP method was sensitive in detecting isotopic assimilation by individual operational taxonomic units (OTUs), as substrate assimilation was observed after only 24 h. Many uncultivated free-living microbial taxa are newly implicated in the cycling of dissolved proteins affiliated with the Verrucomicrobia, Planctomycetes, Actinobacteria and Marine Group II (MGII) Euryarchaeota. In addition, a particle-associated community actively cycling DON was discovered, dominated by uncultivated organisms affiliated with MGII, Flavobacteria, Planctomycetes, Verrucomicrobia and Bdellovibrionaceae. The number of taxa assimilating protein correlated with genomic representation of TonB-dependent receptor (TBDR)-encoding genes, suggesting a possible role of TBDR in utilization of dissolved proteins by marine microbes. Our results significantly expand the known microbial diversity mediating the cycling of dissolved proteins in the ocean.

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“…In estuaries, DFAA seems to support a large fraction (if not all) of bacterial production (Billen and Fontigny 1987; Jorgensen et al 1993;Hoch and Kirchman 1995). Dissolved combined amino acids ' Corresponding author.…”

Section: Introductionmentioning

confidence: 99%

Concentrations and uptake of neutral monosaccharides along 14°W in the equatorial Pacific: Contribution of glucose to heterotrophic bacterial activity and the DOM flux

Rich

Ducklow²,

Kirchman

1996

Limnology & Oceanography

162

168

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We examined concentrations and uptake of dissolved neutral monosaccharides (DNMS) in order to determine the contribution of DNMS to heterotrophic bacterial production and to the flux of dissolved organic matler (DOM) in the equatorial Pacific. DNMS concentrations were greater during El Nifio-affected months of February-April 1992 than during August-October 1992; in contrast, glucose turnover was the oppositeturnover was faster in August-October than in February-April. The variation in sugar concentrations and turnover probably resulted from El Nifio-induced changes in primary production; as El Nifio waned primary production increased, which appeared to stimulate bacterial activity, especially glucose turnover, that in turn forced down DNMS concentrations. In all months, however, DNMS concentrations were low, especially com:pared with total dissolved organic carbon concentrations (< 1%). Glucose was the dominant neutral monosaccharide and alone supported 15-47% of bacterial production. Other monosaccharides apparently did not support much bacterial growth; concentrations of other sugars were low, as probably was turnover. Respiration of glucose (30-60% of uptake) and mannose (60-90%) was relatively high, suggesting that DNMS supported a large fraction of bacterial respiration as well as biomass production. These results point to the importance of DNMS and glucose in particular in supporting bacterial growth and in contributing to the flux #of labile DOM.The concentration of labile dissolved organic matter (DOM) in aquatic ecosystems is usually low, but rates of bacterial activity and biomass production (Cole et al. 1988;Ducklow and Carlson 1992) indicate that DOM fluxes can be quite high. In spite of the recognized importance of DOM, we have few direct measures of DOM fluxes and know little about the composition and uptake of specific components of&e labile DOM pool. Nearly all previous studies on labile DOM have focused on dissolved free amino acids (DFAA) and on the support of bacterial production by DFAA.Free amino acids can provide much C and N for bacterial growth, which in turn suggests that the DFAA is a large component of the labile DOM flux in at least some marine environments. In estuaries, DFAA seems to support a large fraction (if not all) of bacterial production (Billen and Fontigny 1987; Jorgensen et al. 1993;Hoch and Kirchman 1995). Dissolved combined amino acids ' Corresponding author. AcknowledgmentsWe thank R. Penner for his comments about the manuscript.

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Dynamics of a Phaeocystis-dominated spring bloom in Belgian coastal waters. II. Bacterioplankton dynamics

Cited by 151 publications

References 22 publications

Microbial breakdown of Phaeocystis mucopolysaccharides

Microbial breakdown of Phaeocystis mucopolysaccharides

Diverse, uncultivated bacteria and archaea underlying the cycling of dissolved protein in the ocean

Concentrations and uptake of neutral monosaccharides along 14°W in the equatorial Pacific: Contribution of glucose to heterotrophic bacterial activity and the DOM flux

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