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Williams, B. L.; Silcock, D. J.

doi:10.1023/a:1010675601613

Cited by 15 publications

(2 citation statements)

References 20 publications

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“…For example, microbes secrete enzymes that readily mineralize organic P and can quickly assimilate orthophosphate released into pore water (Richardson, 1985;Kellogg and Bridgham, 2003;Noe et al, 2003). Microbes also regulate P in sediments through biomass, which can account for up to 25-50% of the total P in wetland mineral sediments (Wright et al, 2001;McDowell and Sharpley, 2003) and up to 70% of total P in hydrologically isolated sediments (Williams and Silcock, 2001).…”

Section: Introductionmentioning

confidence: 99%

Phosphorus Forms in Sediments of a River-Dominated Estuary

et al. 2018

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Estuaries are biologically productive transition zones between land and sea that play a vital role in transforming, recycling, and sequestering nutrients and organic matter, thus influencing nutrient loading to coastal systems. Yet, the processes involved in phosphorus (P) transformation and cycling among inorganic and organic P forms are poorly known in estuaries. To better understand the potential for P transformation and sequestration, we identified P forms and estimated their contributions to total P in intertidal wetland sediments of a river-dominated estuary (Columbia River, Oregon, USA) using solution 31 P nuclear magnetic resonance spectroscopy (P-NMR). Inorganic P forms dominated sediment P extracts throughout the estuary, with orthophosphate accounting for 71-84% of total extracted P. However, biologically-derived inorganic and organic P forms were also detected. Polyphosphates were found in sediment extracts throughout the estuary, contributing as much as 10% of extracted P. Similar to other wetlands, orthophosphate monoesters and diesters made approximately equal contributions (∼ 20%) to total extracted P. However, monoesters (e.g., phytate) were more abundant in sedimentary environments characterized by low organic matter content, while diesters (e.g., DNA) were more abundant in sedimentary environments with high organic matter, regardless of salinity. Collectively, the data show strong evidence for P transformation in sediments of a large, river-dominated estuary, which influences its transport to the coastal Pacific Ocean via the expansive Columbia River plume.

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Section: Introductionmentioning

confidence: 99%

Phosphorus Forms in Sediments of a River-Dominated Estuary

et al. 2018

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“…If phosphatase activity was a simple function of enzyme production by the natural assemblage, this would suggest that a larger component of bacterial metabolism was devoted to scavenging phosphorus with migration down the estuary. This may be counterintuitive given that pocosin bog water is typically much more phosphorus-limiting to bacterial metabolism than estuarine or marine waters . However, based on the findings that phosphatase activity of both Free-AP and LCA-AP are inhibited by an order of magnitude from 21 to 0 PSU (Figure ), this relationship may be more of a function of inhibition of microbially expressed enzyme rather than devotion of a greater amount of cellular resources to phosphate cycling down estuary.…”

Section: Resultsmentioning

confidence: 99%

Eco-friendly Organic Nanotubes Encapsulating Alkaline Phosphatase and Ecotoxicology of Nanotubes to Natural Bacterial Assemblages in Coastal Estuarine Waters

Montgomery¹,

Collins²,

Boyd³

et al. 2019

ACS Omega

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Phosphatase-encapsulated nanotubes have potential in environmental remediation of organophosphate contaminants (e.g., pesticides, nerve agents). We investigated alkaline phosphatase (AP) activity when encapsulated in self-assembled lithocholic acid nanotubes (LCA-AP) in water samples along a transect from Cypress bog headwaters through estuarine waters and to Atlantic Ocean seawater. Apparent V max (app V max) for both LCA-AP and unencapsulated AP (Free-AP) was most rapid at mid-estuary and most inhibited at the humic-rich bog. LCA-AP retained a higher-activity percentage, suggesting that encapsulation may afford some protection from denaturing effects of humics. Apparent K m (app K m) of Free-AP (1–2.3 μM) was largely unaffected by preincubation with transect water, whereas app K m of LCA-AP was higher with bog water (5.3 μM) relative to other stations. When comparing Free-AP and LCA-AP, increasing salinity generally decreased the catalytic efficiency of the LCA-AP, but had little effect on that of the Free-AP. In addition, both showed the same pattern of lowest efficiency in bog water, which increased with salinity to 21 practical salinity units before decreasing at full-strength salinity. With the exception of the similarly low values in the bog water (1.04 for LCA-AP, 1.34 for Free-AP), absolute values of catalytic efficiency for LCA-AP were about 17% (range: 14.5–19.3%) of that for Free-AP. Nanotube addition had little ecotoxicological effect on heterotrophic bacterial production in waters sampled along the transect. Microbially associated, intrinsic AP activity showed a similar pattern along the transect to LCA-AP, suggesting that AP environmental control and regulation in nature may inform study of nanomaterials.

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The total phosphorus budget of a peat‐covered catchment

et al. 2016

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Although many studies have considered the carbon or greenhouse gas budgets of peat ecosystems, only a few have considered the nutrient budget of peat soils, and this, in turn, has limited the ability of studies to consider the impact of changes in climate and atmospheric deposition on the phosphorus budget of a peat soil. This study considered the total phosphorus (P) budget of an upland peat‐covered catchment over the period 1993 to 2012. The study has shown (i) total atmospheric deposition of phosphorus varied from 62 to 175 kg P/km2/yr; (ii) the carbon:phosphorus ratio of the peat profile declines significantly from values in the litter layer (C:P = 1326) to approximately constant at 30 cm depth (C:P = 4240); (iii) the total fluvial flux of phosphorus varied from 49 to 111 kg P/km2/yr, of which between 45 and 77% was dissolved P; and (iv) the total phosphorus sink varied from −5.6 to +71.7 kg P/km2/yr with a median of +29.4 kg P/km2/yr, which is within the range of the estimated long‐term accumulation rate of phosphorus in the peat profile of between 3 and 32 kg P/km2/yr. The phosphorus budget of the peat ecosystem relies on rapid recycling near the soil surface, and this means that any vegetation management may critically deprive the ecosystem of this nutrient.

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Cited by 15 publications

References 20 publications

Phosphorus Forms in Sediments of a River-Dominated Estuary

Phosphorus Forms in Sediments of a River-Dominated Estuary

Eco-friendly Organic Nanotubes Encapsulating Alkaline Phosphatase and Ecotoxicology of Nanotubes to Natural Bacterial Assemblages in Coastal Estuarine Waters

The total phosphorus budget of a peat‐covered catchment

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