Dynamics of a Pasture Soil Microbial Community after Deposition of Cattle Urine Amended with [
            <sup>13</sup>
            C]Urea

Petersen, Søren O.; Roslev, Peter; Bol, Roland

doi:10.1128/aem.70.11.6363-6369.2004

Cited by 49 publications

(30 citation statements)

References 52 publications

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“…The importance of urea as a N source for phytoplankton and bacteria has been well documented (Berman & Bronk 2003, Jørgensen 2006. However, the importance of urea as a C source is unclear, and has been studied rarely and with contradictory results (Petersen et al 2004, Jørgensen 2006. In the 1980s, investigators used radioactive 14 C labeled urea in parallel with 15 N labeled urea (Price & Harrison 1988 and references therein) to measure urea uptake, and an uncoupling between N and C uptake from urea was often found.…”

Section: Discussionmentioning

confidence: 99%

“…The use of dually labeled substrates is necessary to increase our insight into the role of DON cycling in pelagic ecosystems and to further our understanding of DON acquisition strategies by microbes. To take this relatively unexplored field of research one step further and study in detail which organisms are involved in the uptake of inorganic versus organic substrates, biomarkers such as PLFA (Boschker & Middelburg 2002, Petersen et al 2004) and D-alanine (Veuger et al 2005) can be valuable tools in combination with dually labeled substrates. Heterotrophs (bacteria) and photoautotrophs differ with respect to their uptake of C and N. Photoautotrophs can assimilate DIC during photosynthesis in the light and incorporate N throughout the entire day, resulting in a temporarily uncoupled uptake of C and N. Heterotrophs grow on organic substrates and usually take up C and N at the same time, but their relative use of C and N may differ.…”

Section: Discussionmentioning

confidence: 99%

“…Previous studies addressing this question on natural samples are few. Petersen et al (2004) showed that both heterotrophic and nitrifying bacteria can incorporate a small amount of C from urea. Jørgensen (2006) reported urea uptake by estuarine bacteria and concluded that uptake is variable and rather unpredictable.…”

Section: Introductionmentioning

confidence: 99%

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Uptake of dissolved inorganic nitrogen, urea and amino acids in the Scheldt estuary: comparison of organic carbon and nitrogen uptake

Andersson¹,

Rijswijk²,

Middelburg³

2006

Aquat. Microb. Ecol.

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Uptake of dissolved ammonium, nitrate, nitrite, urea and amino acids was studied in the Scheldt estuary in different seasons over a salinity gradient. The importance of inorganic nitrogen sources was compared to that of urea and amino acids and the relative use of urea and amino acid nitrogen and carbon was studied. Urea and amino acids constituted up to 43 and 29% of total nitrogen uptake, respectively, and were of similar importance as inorganic substrates. Ammonium oxidation by nitrifiers and ammonium uptake by algae and bacteria were of similar magnitude. In January, April and November, amino acids constituted a source of both nitrogen and carbon while urea mainly constituted a source of carbon. During the summer months, amino acids were used mainly as a source for nitrogen, while urea was a source for both carbon and nitrogen; urea was rarely used as nitrogen substrate alone. Due to this seasonal uncoupling of nitrogen and carbon assimilation, dually labeled substrates are necessary to assess the importance of urea and amino acids as substrates for organic nitrogen and carbon.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Uptake of dissolved inorganic nitrogen, urea and amino acids in the Scheldt estuary: comparison of organic carbon and nitrogen uptake

Andersson¹,

Rijswijk²,

Middelburg³

2006

Aquat. Microb. Ecol.

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“…In a study of urea uptake in soils, a minor incorporation of 13 C from 13 C urea was detected in phospholipid fatty acids in both heterotrophic and nitrifying bacteria (Petersen et al 2004). It is uncertain if utilization of urea-C provides bacteria with nutritional advantages.…”

Section: Dfaa and Nhmentioning

confidence: 99%

Uptake of urea by estuarine bacteria

Jørgensen

2006

Aquat. Microb. Ecol.

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Uptake of urea was studied in batch cultures of natural bacterial assemblages or in GF/C filtered water from 4 estuarine sites, and was related to utilization of other N compounds and the total bacterial N production. During spring in Roskilde Fjord, Denmark, urea uptake varied 100-fold and sustained 0.6 to 44% of the bacterial N demand, while uptake of dissolved free amino acids (DFAA) met 12 to 53% of the N demand. Enrichment with NH 4 + and DFAA reduced the urea uptake by up to 2.8-fold, demonstrating a higher preference for NH 4 + and DFAA than urea. In Knebel Vig, Denmark, bacterial uptake of urea varied significantly during a 9 d provoked algal bloom (mesocosms enriched with N, P, or Si). At Day 1, uptake of urea and DFAA was similar, but during development of a diatom bloom, bacterial urea uptake either increased 7-fold (Day 5) or was insignificant (Day 9). In contrast, urea uptake in the control mesocosms remained unchanged. Urea uptake by the bacterial assemblages was on average 1.6-fold higher than the in situ (bacteria and algae) dark uptake, which again was 16-fold lower than the in situ light uptake. Urea sustained 0.2 to 30% (nutrient-enriched mesocosms) and 9 to 41% (control) of the bacterial N demand, but NH 4 + , NO 3 -and DFAA were more important N sources. Bacterial preference for urea or NH 4 + alone, or in combination with glucose, was examined in the Limfjorden estuary, Denmark. Relative to controls, a 2-fold higher biomass was produced whether NH 4 + or urea was the N source, but urea sustained < 30% of the N biomass production and was less important than the ambient DFAA pool. In contrast to the Limfjorden studies, when enriched with glucose, bacteria in Santa Rosa Sound, Florida, USA, produced a lower biomass with urea than with NH 4 + . Enrichment with urea stimulated the DFAA assimilation, peptidase activity and utilization of NO 3 -, and urea made up < 50% of the N incorporation. The studies demonstrate that urea uptake rates by estuarine bacteria are variable and often unpredictable. Uptake of urea will typically be lower than of NH 4 + and DFAA, but occasionally, urea uptake can be of importance similar to NH 4 + and DFAA.KEY WORDS: Urea · Bacterial uptake · DFAA · Ammonium-Bacterial N budgetsResale or republication not permitted without written consent of the publisher

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“…Enhanced nitrification in response to grazing pressure has been reported in different unfertilized grassland ecosystems (Groffman et al, 1993;Frank et al, 2000;Le Roux et al, 2003;Patra et al, 2005). These changes can be explained by factors such as urine and dung input by herbivores (Ruess and McNaughton, 1987;Petersen et al, 2004) and changes in competition for N between microorganisms and plants (Busso et al, 2001;Hamilton and Frank, 2001). It has been further shown that grazinginduced differences in nitrification levels in grasslands are associated with changes in the abundance and community structure of ammonia-oxidizing bacteria (AOB) that were thought to be the key players of the first step of nitrification: oxidation of ammonia into nitrite (Patra et al, 2005(Patra et al, , 2006.…”

Section: Introductionmentioning

confidence: 99%

Effects of aboveground grazing on coupling among nitrifier activity, abundance and community structure

et al. 2007

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The influence of switches in grassland management to or from grazing on the dynamics of nitrifier activity, as well as the abundance of ammonia-oxidizing bacteria, AOB and ammonia-oxidizing archeae, AOA, was analyzed for two years after changing management. Additionally community structure of AOB was surveyed. Four treatments were compared in mesocosms: grazing on previously grazed grassland (G-G); no grazing on ungrazed grassland (U-U); grazing on ungrazed grassland (U-G) and cessation of grazing on grazed grassland (G-U). Nitrifier activity and abundance were always higher for G-G than U-U treatments and AOB community structure differed between these treatments. AOA abundance was in the same range as AOB abundance and followed the same trend. Grazing led to a change in AOB community structure within o5 months and a subsequent (5-12 months) increase in nitrifier activity and abundance. In contrast, cessation of grazing led to a decrease in nitrifier activity and abundance within o5 months and to a later (5-12 months) change in AOB community structure. Activity in G-U and U-G was similar to that in U-U and G-G, respectively, after 12 months. Sequence analysis of 16S rRNA gene clones showed that AOB retrieved from soils fell within the Nitrosospira lineage and percentages of AOB related to known Nitrosospira groups were affected by grazing. These results demonstrate that AOB and AOA respond quickly to changes in management. The selection of nitrifiers adapted to novel environmental conditions was a prerequisite for nitrification enhancement in U-G, whereas nitrification decrease in G-U was likely due to a partial starvation and decrease in the abundance of nitrifiers initially present. The results also suggest that taxonomic affiliation does not fully infer functional traits of AOB.

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Dynamics of a Pasture Soil Microbial Community after Deposition of Cattle Urine Amended with [ ¹³ C]Urea

Cited by 49 publications

References 52 publications

Uptake of dissolved inorganic nitrogen, urea and amino acids in the Scheldt estuary: comparison of organic carbon and nitrogen uptake

Uptake of dissolved inorganic nitrogen, urea and amino acids in the Scheldt estuary: comparison of organic carbon and nitrogen uptake

Uptake of urea by estuarine bacteria

Effects of aboveground grazing on coupling among nitrifier activity, abundance and community structure

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Dynamics of a Pasture Soil Microbial Community after Deposition of Cattle Urine Amended with [ 13 C]Urea

Cited by 49 publications

References 52 publications

Uptake of dissolved inorganic nitrogen, urea and amino acids in the Scheldt estuary: comparison of organic carbon and nitrogen uptake

Uptake of dissolved inorganic nitrogen, urea and amino acids in the Scheldt estuary: comparison of organic carbon and nitrogen uptake

Uptake of urea by estuarine bacteria

Effects of aboveground grazing on coupling among nitrifier activity, abundance and community structure

Contact Info

Product

Resources

About

Dynamics of a Pasture Soil Microbial Community after Deposition of Cattle Urine Amended with [ ¹³ C]Urea