Proteins are a major component of dissolved organic nitrogen (DON) leached from terrestrially aged Eucalyptus camaldulensis leaves

2016 ◽  
Vol 13 (5) ◽  
pp. 877 ◽  
Author(s):  
Clayton W. Harris ◽  
Ewen Silvester ◽  
Gavin N. Rees ◽  
John Pengelly ◽  
Ljiljana Puskar
Keyword(s):  
Leaf Litter ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Eucalyptus Camaldulensis ◽  
Aquatic Systems ◽  
Nutrient Source ◽  
Nitrogen Pool ◽  
Dissolved Nitrogen ◽  
Ftir Microspectroscopy ◽  
Proteinaceous Material

Environmental contextDissolved organic nitrogen often constitutes the largest portion of the dissolved nitrogen pool yet is a commonly overlooked nutrient source in aquatic systems. Terrestrially aged Eucalyptus camaldulensis, a common lowland leaf litter species, rapidly released proteinaceous dissolved organic nitrogen during the first 24h of leaching. The results indicate that terrestrial leaf litter may play an important role in satisfying nutrient demand within aquatic systems through both direct deposition and floodplain interactions. AbstractUnderstanding sources and forms of dissolved nitrogen is of critical importance to the management of aquatic systems worldwide. Dissolved organic nitrogen (DON) often constitutes the largest portion of the dissolved nitrogen pool, yet is commonly overlooked as a nutrient source to aquatic food webs, likely owing to its bound nature within organic material and the non-specific methods by which it is measured. In this study, we determined the protein and peptide (dissolved combined amino acid (DCAA)) contribution to DON leached from Eucalyptus camaldulensis leaves over 24h. The distribution of proteinaceous material in unleached and leached leaves was characterised using Fourier-transform infrared (FTIR) microspectroscopy to determine the likely source of DCAA within the leaf tissue. DCAAs were found to be a significant component (38.5%) of the leached DON; however, >90% of the leaf protein remained in the leaves after 24h. FTIR microspectroscopy shows that proteinaceous material is strongly partitioned to fungal colonised palisade cells in the leaf mesophyll, with evidence for depletion of this material after leaching. Comparison of leaching kinetics in the presence and absence of a microbial inhibitor (sodium azide) suggests that microbial uptake or adsorption commences within the timescales of these leaching experiments. The work shows that DON in the form of peptides and proteins leached from leaf litter is a likely source of bioavailable nutrients to in-stream and floodplain systems.

scholarly journals Characteristics of Dissolved Organic Nitrogen in the Sediments of Six Water Sources in Taihu Lake, China

2019 ◽  
Vol 16 (6) ◽  
pp. 929 ◽  
Author(s):  
Xiaofan Yang ◽  
Xueyu Wei ◽  
Xiaoping Xu ◽  
Yu Zhang ◽  
Jincheng Li ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Drinking Water ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Taihu Lake ◽  
Water Sources ◽  
Dissolved Nitrogen ◽  
Total Dissolved Nitrogen ◽  
Endogenous Release ◽  
Molecular Weight Fractions

KCl-extractable sediment dissolved organic nitrogen (KS-DON) extracted from sediments near drinking water intakes of six drinking water sources in Taihu Lake in China was partitioned into hydrophobic and hydrophilic fractions and high/low molecular weight fractions. The results showed that the total dissolved nitrogen (TDN) contents of the extracts ranged from 67.78 to 128.27 mg/kg. KS-DON was the main TDN species, accounting for more than 50%, with NH4+-N and NO3−-N averaging 30% and 20%, respectively. The molecular weight fractions of <1 kDa accounted for almost half of KS-DON. Hydrophilic compounds accounted for more than 75% of KS-DON. Three fluorescence peaks were identified: soluble microbial byproducts (A); protein-like substances (B); and humic acid-like substances (C). It is concluded that the KS-DON in Taihu Lake sources has higher bioavailability and higher risk of endogenous release. Ecological dredging and establishment of constructed wetlands are possible measures to reduce the release of endogenous nitrogen.

scholarly journals Vertical distribution of total dissolved nitrogen and dissolved organic nitrogen in seawater.

1990 ◽  
Vol 24 (4) ◽  
pp. 245-254 ◽  
Author(s):  
Yoshiaki Maita ◽  
Mitsuru Yanada
Keyword(s):  
Vertical Distribution ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Dissolved Nitrogen ◽  
Total Dissolved Nitrogen

scholarly journals The importance of riparian zones on stream carbon and nitrogen export in a temperate, agricultural dominated landscape

2012 ◽  
Vol 9 (6) ◽  
pp. 7465-7497 ◽  
Author(s):  
T. Wohlfart ◽  
J.-F. Exbrayat ◽  
K. Schelde ◽  
B. Christen ◽  
T. Dalgaard ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Dissolved Organic Carbon ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Agricultural Land ◽  
Stream Water ◽  
Soil Types ◽  
Organic Soils ◽  
Dissolved Nitrogen ◽  
Total Dissolved Nitrogen

Abstract. The surrounding landscape of a stream has crucial impacts on the aquatic environment. This study pictures the hydro-biogeochemical situation of the Tyrebaekken creek catchment in central Jutland, Denmark. The intensively managed agricultural landscape is dominated by rotational croplands. One northern and one southern stream run through the catchment before converging to form a second order brook. The small catchments mainly consist of sandy soil types besides organic soils along the riparian zone of the streams. The aim of the study was to characterise the relative influence of soil type and land use on stream water quality. Nine snapshot sampling campaigns were undertaken during the growing season of 2009. On each sampling day, 20 points along the stream were sampled as well as eight drain outlets and two groundwater wells. Total dissolved nitrogen, nitrate, ammonium nitrogen and dissolved organic carbon (DOC) concentrations were measured and dissolved organic nitrogen (DON) was calculated for each grabbed sample. Electro-conductivity, pH and flow velocity were measured during sampling. Statistical analyses showed significant differences between the northern, southern and converged stream parts, especially for nitrate concentrations with average values of 9.6 mg N l−1, 1.4 mg N l−1 and 3.0 mg N l−1, respectively. Furthermore, throughout the sampling period DON concentrations increased from 0.1 mg N l−1 to 2.8 mg N l−1 and from 0.1 mg N l−1 to 0.8 mg N l−1in the northern and southern streams, respectively. This corresponded to a contribution of up to 81% to total dissolved nitrogen. Multiple-linear regression analyses performed between chemical data and landscape charateristics showed a significant negative influence of organic soils on instream N concentrations and corresponding losses in spite of their overall minor share of the agricultural land (12.9%). On the other hand, organic soil frequency was positively correlated to the corresponding dissolved organic carbon concentrations. Croplands also had a significant influence but with weaker correlations. For our case study we conclude that soil types and corresponding biogeochemical properties have a major influence on stream water chemistry. Meanwhile, the contribution of dissolved organic nitrogen to the total nitrogen budget was substantial in this agricultural dominated landscape.

scholarly journals Extreme dissolved organic nitrogen fluxes in the human impacted Pamba River, Kerala, India

2013 ◽  
Vol 10 (10) ◽  
pp. 16137-16171 ◽  
Author(s):  
S. Elizabeth David ◽  
T. C. Jennerjahn
Keyword(s):  
Land Use ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Aquatic Systems ◽  
Global Maximum ◽  
Livestock Farming ◽  
Tropical River ◽  
Human Interventions ◽  
Anthropogenic Nitrogen ◽  
River Catchments

Abstract. Cultural eutrophication of coastal aquatic systems is a major undesired phenomenon of today, which is mainly ascribed to the application of inorganic fertilizers in agriculture. Consequently, dissolved inorganic nitrogen (DIN) is considered the major problem and widely studied. However, human interventions also strongly influence the riverine dissolved organic nitrogen (DON) concentrations and fluxes. Studies of nutrient inputs from tropical river catchments are biased towards DIN, even though they account for only a portion of the total dissolved nitrogen (TDN) pool, whereas the rest is comprised of DON and has been largely ignored. The tropical Pamba River was studied because of its manifold human activities in the catchment and was sampled during the south west monsoon (SWM), north east monsoon (NEM) and the pre monsoon (PM) months during 2010 to 2013. The largest pilgrim center on earth, the Sabarimala temple, located in the upstream forest is a unique feature of the catchment. Fertilizer application, livestock farming and inadequate sewage treatment are the prevailing land use practices. The goals of this study were to (i) define cause-effect relationships by assessing the effect of various human interventions such as the pilgrims, agriculture and sewage disposal in combination with the seasonal variations in hydrology on the DON concentrations and fluxes and to (ii) quantify the inputs from respective land use segments. The global maximum DON concentration (29 302 μM) was measured for the Pamba River. Pilgrim activities, high population density, agricultural and livestock farming as well as the lack of infrastructure for sanitation facilities were the cause for extremely high DON concentrations and fluxes in the plantation and settlement with mixed tree crop (SMT) segments. A DON yield of 745 kg ha−1 yr−1 was calculated for the Pamba catchment. The total DON inputs from all quantifiable sources amounted to 514 kg ha−1 yr−1 comprising of 69% of the total Pamba DON yield. In the Pamba River, sewage is the major source of DON and the unique Sabarimala pilgrim event accounts for most of it. Nevertheless, sewage input from the rest of the densely-populated catchment is high, which is a common feature of developing countries that lack adequate sanitation and water technology, i.e. in South and Southeast Asia and tropical Africa. Our study shows that DON makes up a significant portion of anthropogenic nitrogen in rivers, in particular in those regions, which are, however, scarce in respective data. It underscores the need for more quantitative studies from densely-populated tropical river catchments in order to improve global nitrogen budgets and the assessment of the consequences of anthropogenic nitrogen inputs into coastal aquatic systems.

Adsorption of dissolved nitrogen by forest mineral soils

2009 ◽  
Vol 39 (12) ◽  
pp. 2381-2390 ◽  
Author(s):  
D.N. Kothawala ◽  
T.R. Moore
Keyword(s):  
Soil Properties ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Mineral Soil ◽  
Organic Soil ◽  
Nutrient Sources ◽  
Dissolved Nitrogen ◽  
Soil Solutions ◽  
Mineral Soils ◽  
Similar Soil

Dissolved nitrogen (N) species, including ammonium (NH4+-N), nitrate (NO3–-N), and dissolved organic nitrogen (DON), are important nutrient sources in soils. The mobility of DON and NH4+-N in soil solutions is influenced by abiotic adsorption to mineral soil particle surfaces. We determined relationships between soil properties and their ability to adsorb NH4+-N, NO3–-N, and DON, using batch experiments. A range of 41 mineral horizons was collected from across Canada, including Podzols, Brunisols, Luvisols, Gleysols, and an organic soil. The adsorption of DON and dissolved organic carbon (DOC) were positively correlated (R2 = 0.86), and both were best explained by the amount of iron and aluminum associated with poorly crystalline phases. Adsorption of NH4+-N was strongest in Gleysols and Luvisols, while adsorption of NO3–-N was weak in all soils. A reduction in the DOC:DON ratio was observed for most mineral horizons (89%) after equilibration from an original ratio of 35:1. Mineral horizons with a net desorption of DON had a significantly greater reduction in the final DOC:DON ratios than horizons with a net adsorption of DON. The results from this study found that while similar soil properties could predict DOC and DON adsorption, DON was slightly more mobile than DOC.

Electro-Oxidation to Convert Dissolved Organic Nitrogen and Soluble Non-Reactive Phosphorus to More Readily Removable and Recoverable Forms

Chemosphere ◽  
2021 ◽  
pp. 130876
Author(s):  
Synthia P. Mallick ◽  
Donald R. Ryan ◽  
Kaushik Venkiteshwaran ◽  
Patrick J. McNamara ◽  
Brooke K. Mayer
Keyword(s):  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Electro Oxidation ◽  
Reactive Phosphorus
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