Mineralization of Organic Material and Bacterial Dynamics in Mississippi River Plume Water

Gardner, Wayne S.; Cotner, James B.; Eadie, Brian J.; Cavaletto, Joann F.; Benner, Ronald; Chin-Leo, Gerardo

doi:10.2307/1352750

Cited by 41 publications

(19 citation statements)

References 32 publications

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“…The latter indicated that nitrification at intermediate salinities was supported by the rapid regeneration of NH4+ within the plume. Dark net NH4+ regeneration rates (Table 5) in the present investigation were similar to dark NH4+ regeneration rates (0.05 to 0.22 pM h") reported from the plume by Gardner et al (1994) and 15NH4+ regeneration rates (<0.05 to >4.5 pM h-l) obtained under simulated in situ light conditions (Dortch et al 1992a. The distribution of NH4+ regeneration reported by the above authors and observed in the present investigation also indicated that NH4+ regeneration within the plume is often highest at intermediate salinities where we observed the highest rates of nitrification.…”

Section: Nitrogen Fluxes and Nitrification In The Mississippi River Psupporting

confidence: 89%

“…Plume heterotrophic bacterial production and O2 consumption rates in the present investigation were 2-to 4-fold greater than values measured in February or July (Benner et al 1992, Chin-Leo & Benner 1992, Gardner et al 1994). Higher springtime rates of plume heterotrophic bacterial production and community Oz consumption suggested that these processes may be influenced by higher seasonal discharge from the Mississippi River.…”

Section: Influence Of Mississippi River Discharge On Plume Bacterial contrasting

confidence: 71%

“…In the Mississippi River plume, increasingly favorable light regimes and high concentrations of riverine DIN stimulate photosynthesis and the production of PON at intermediate plume salinities (Lohrenz et al 1990, Lopez-Veneroni & Cifuentes 1992 Amino acid uptake rates measured during 15NH4+ regeneration experiments indicate that bacterial remineralization of DON contributes to the regeneration of NH4+ in the plume. Size-fractionation experiments, however, indicate that much of the NH4+ regeneration at intermediate plume salinities occurs in the >1.0 pm size fraction (Gardner et al 1994) suggesting that the mesozooplankton and other larger organisms also contribute to NI-y regeneration within the plume. Mesozooplankton are present in high concentrations (100 to >I000 1-I) at intermediate plume salinities and consume a substantial portion of plume primary production in the late spring and summer months (Dagg & Ortner 1992.…”

Section: Nitrogen Fluxes and Nitrification In The Mississippi River Pmentioning

confidence: 96%

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Community metabolism and nutrient cycling in the Mississippi River plume: evidence for intense nitrification at intermediate salinities

Pakulski¹,

Benner²,

Amon³

et al. 1995

Mar. Ecol. Prog. Ser.

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Community respiration, net nutrient fluxes and heterotrophic bacterial production were investigated in the Mississippi River (USA) plume during May 1992 using dark bottle incubations of unfiltered water. Highest rates of community Os consumption and dissolved inorganic carbon regeneration were observed at intermediate (10 to 27%0) plume salinities. Plume surface 0; consumption rates were 2-to 4-fold greater than rates reported previously during the summer and winter. Heterotrophic bacterial production ([3H]-leucine incorporation) was also highest at intermediate salinities and 2-to 4-fold greater than rates reported from other seasons. Net regeneration of was observed in the 0 to l8%0 region of the plume while low rates of net NH4+ consumption were observed at 27%0. Net NO9-regeneration in the Mississippi River suggested the occurrence of nitrification m the fresh waters of the delta. Serendipitous observations of rapid N o 3 regeneration at 18 and 27%0 indicated the development of intense nitrification at intermediate plume salinities. Nitrification accounted for 20 to >50 % of the community 0; demand at 18 and 27%o. These data indicated that nitrification was an important component of the plume nitrogen cycle and contributed significantly to oxygen consumption in the plume.

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Section: Nitrogen Fluxes and Nitrification In The Mississippi River Psupporting

confidence: 89%

Section: Influence Of Mississippi River Discharge On Plume Bacterial contrasting

confidence: 71%

Section: Nitrogen Fluxes and Nitrification In The Mississippi River Pmentioning

confidence: 96%

See 1 more Smart Citation

Community metabolism and nutrient cycling in the Mississippi River plume: evidence for intense nitrification at intermediate salinities

Pakulski¹,

Benner²,

Amon³

et al. 1995

Mar. Ecol. Prog. Ser.

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“…Where biomass values are not given, export flows were unconstrained. Sources from which parameters were estimated: Gardner et al (1994), Redalje et al (1994), Trefry et al (1994), Dagg 1995, Strom & Strom (1996, Opsahl & Benner (1998), Goolsby et al (1999), Lohrenz et al (1999), Benner & Opsahl (2001 Inverse calculations. Details of the inverse procedure for planktonic food webs can be found in Vézina & Platt (1988) & Vézina (1989.…”

Section: Methods and Model Approachmentioning

confidence: 99%

Sedimentation, carbon export and food web structure in the Mississippi River plume described by inverse analysis

Breed

Jackson²,

Richardson³

2004

Mar. Ecol. Prog. Ser.

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“…Cotner & Gardner 1993, Gardner et al 1994, depending on the relative C and N availability of the substrate (Goldman et al 1987), or by excretion from grazers such as heterotrophic flagellates and ciliates grazing on bacteria (Caron & Goldman 1990) that have assimilated the humic-associated N. Photochemical release of ammonium from HS was also recently described by Bushaw et al (1996), which presents another mechanism by which inorganic N can become available for bacterial and phytoplankton uptake.…”

Section: Introductionmentioning

confidence: 98%

Cycling of biologically available nitrogen in riverine humic substances between marine bacteria, a heterotrophic nanoflagellate and a photosynthetic dinoflagellate

Carlsson¹,

Granéli²,

Segatto³

1999

Aquat. Microb. Ecol.

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The effects of freshwater dissolved organic matter (DOM) on the growth of a community of coastal marine bacteria, a heterotrophic flagellate (Cafeteria roenbergensis) and an autotrophic dinoflagellate (Prorocentrum minimum) were studied in an experimental system incubated under laboratory conditions. The DOM used was in the form of rivenne-isolated hurnic substances (HS). The addition of HS increased bacterial growth, which in turn increased growth of C. roenbergensis. P. minimum attained higher abundance, higher chlorophyll a content per cell and a higher cellular nitrogen (N) content when grown with HS addition. In the treatment with P. minimum and bacteria approximately 35 % of the humic-associated N was utilized by the organisms, as indicated by the increase of particulate N in P, minimum and bacteria cells. There was no net accumulation of inorganic N in any treatment, indicating that bacteria acted as a sink for N when utilizing the HS as substrate. Moreover, grazing activity by C. roenbergensis did not cause any significant accumulation of inorganic N in treatments with C. roenbergensis and bacteria, suggesting that bacteria used the inorganic N released by the grazers. Thus, the increased growth of P. minimum with HS present was probably not caused by bacterial mineralization of inorganic nitrogen, but could have been caused by the algae using dissolved organic nitrogen compounds.

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Mineralization of Organic Material and Bacterial Dynamics in Mississippi River Plume Water

Cited by 41 publications

References 32 publications

Community metabolism and nutrient cycling in the Mississippi River plume: evidence for intense nitrification at intermediate salinities

Community metabolism and nutrient cycling in the Mississippi River plume: evidence for intense nitrification at intermediate salinities

Sedimentation, carbon export and food web structure in the Mississippi River plume described by inverse analysis

Cycling of biologically available nitrogen in riverine humic substances between marine bacteria, a heterotrophic nanoflagellate and a photosynthetic dinoflagellate

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