scholarly journals Impact of nitrogen compounds on fungal and bacterial contributions to codenitrification in a pasture soil

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
David Rex ◽  
Timothy J. Clough ◽  
Karl G. Richards ◽  
Leo M. Condron ◽  
Cecile A. M. de Klein ◽  
...  
Keyword(s):  
Amino Acid ◽  
Relative Significance ◽  
Total N ◽  
Bacterial Inhibition ◽  
Grazed Pasture ◽  
Fungal Inhibition ◽  
Soil Mesocosms ◽  
The Many ◽  
Acid Substrate

Abstract Ruminant urine patches on grazed grassland are a significant source of agricultural nitrous oxide (N2O) emissions. Of the many biotic and abiotic N2O production mechanisms initiated following urine-urea deposition, codenitrification resulting in the formation of hybrid N2O, is one of the least understood. Codenitrification forms hybrid N2O via biotic N-nitrosation, co-metabolising organic and inorganic N compounds (N substrates) to produce N2O. The objective of this study was to assess the relative significance of different N substrates on codenitrification and to determine the contributions of fungi and bacteria to codenitrification. 15N-labelled ammonium, hydroxylamine (NH2OH) and two amino acids (phenylalanine or glycine) were applied, separately, to sieved soil mesocosms eight days after a simulated urine event, in the absence or presence of bacterial and fungal inhibitors. Soil chemical variables and N2O fluxes were monitored and the codenitrified N2O fluxes determined. Fungal inhibition decreased N2O fluxes by ca. 40% for both amino acid treatments, while bacterial inhibition only decreased the N2O flux of the glycine treatment, by 14%. Hydroxylamine (NH2OH) generated the highest N2O fluxes which declined with either fungal or bacterial inhibition alone, while combined inhibition resulted in a 60% decrease in the N2O flux. All the N substrates examined participated to some extent in codenitrification. Trends for codenitrification under the NH2OH substrate treatment followed those of total N2O fluxes (85.7% of total N2O flux). Codenitrification fluxes under non-NH2OH substrate treatments (0.7–1.2% of total N2O flux) were two orders of magnitude lower, and significant decreases in these treatments only occurred with fungal inhibition in the amino acid substrate treatments. These results demonstrate that in situ studies are required to better understand the dynamics of codenitrification substrates in grazed pasture soils and the associated role that fungi have with respect to codenitrification.

4.1 Soil Factors and Treatments affecting Trace Elements in Crops and Herbage

1983 ◽  
Vol 7 ◽  
pp. 77-85 ◽  
Author(s):  
J. C. Burridge ◽  
J. W. S. Reith ◽  
M. L. Berrow
Keyword(s):  
Trace Elements ◽  
Trace Element Content ◽  
Relative Significance ◽  
North East ◽  
Grazed Pasture ◽  
Animal Feedstuffs ◽  
Using Data ◽  
The Many ◽  
Stocking Rates ◽  
Grass Ley

Despite the extensive knowledge of animals' dietary requirements for trace elements and detailed research into the uptake by plants of nutrients from the soil, it is surprising that the production of animal feedstuffs, having an appropriate trace-element content, still presents a considerable challenge to the agronomist. The present paper draws attention to some of the problems involved, using data from the many years of field-experiment research at the Macaulay Institute for Soil Research. These experiments have been largely restricted to the system of intensive agriculture prevailing in north-east Scotland, where heavily-grazed pasture and conserved herbage are the principal components of animal diets. The 6-7 year crop rotation most commonly practised includes a 3-4 year period of grass ley. The factors discussed have a wider relevance although their relative significance under conditions of low stocking rates, for instance on the rough or natural grazing on hill-land in the U.K. and other countries, will clearly be different.

scholarly journals B0AT1 amino acid transporter complexed with SARS-CoV-2 receptor ACE2 forms a heterodimer functional unit: in situ conformation using radiation inactivation analysis

Function ◽  
2021 ◽  
Author(s):  
Bruce R Stevens ◽  
J Clive Ellory ◽  
Robert L Preston
Keyword(s):  
Amino Acid ◽  
Membrane Trafficking ◽  
Functional Unit ◽  
Membrane Vesicles ◽  
High Energy ◽  
Amino Acid Transporter ◽  
Neutral Amino Acid ◽  
Transport Activity ◽  
Acid Transporter

Abstract The SARS-CoV-2 receptor, Angiotensin Converting Enzyme-2 (ACE2), is expressed at levels of greatest magnitude in the small intestine as compared to all other human tissues. Enterocyte ACE2 is co-expressed as the apical membrane trafficking partner obligatory for expression and activity of the B0AT1 sodium-dependent neutral amino acid transporter. These components are assembled as an [ACE2: B0AT1]2 dimer-of-heterodimers quaternary complex that putatively steers SARS-CoV-2 tropism in the gastrointestinal (GI) tract. GI clinical symptomology is reported in about half of COVID-19 patients, and can be accompanied by gut shedding of virion particles. We hypothesized that within this 4-mer structural complex, each [ACE2: B0AT1] heterodimer pair constitutes a physiological “functional unit.” This was confirmed experimentally by employing purified lyophilized enterocyte brush border membrane vesicles that were exposed to increasing doses of high-energy electron radiation from a 16 MeV linear accelerator. Based on established target theory, the results indicated the presence of Na+-dependent neutral amino acid influx transport activity functional unit with target size mw = 183.7 ± 16.8 kDa in situ in intact apical membranes. Each thermodynamically stabilized [ACE2: B0AT1] heterodimer functional unit manifests the transport activity within the whole ∼345 kDa [ACE2: B0AT1]2 dimer-of-heterodimers quaternary structural complex. The results are consistent with our prior molecular docking modeling and gut-lung axis approaches to understanding COVID-19. These findings advance the understanding of the physiology of B0AT1 interaction with ACE2 in the gut, and thereby potentially contribute to translational developments designed to treat or mitigate COVID-19 variant outbreaks and/or GI symptom persistence in long-haul Post-Acute Sequelae of SARS-CoV-2 (PASC).

scholarly journals 88 Benefits of increasing amino acid intake in late gestation in prolific sows

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 76-76
Author(s):  
Ron Ball ◽  
Crystal L Levesque ◽  
D J Cadogan
Keyword(s):  
Birth Weight ◽  
Amino Acid ◽  
Reproductive Performance ◽  
Essential Amino Acid ◽  
Control Diet ◽  
Genetic Selection ◽  
Late Gestation ◽  
Negative Effects ◽  
Amino Acid Levels ◽  
The Many

Abstract Most sows are fed a constant energy and amino acid supply throughout gestation, in line with the recommendations of most authorities and swine genetic companies. These recommendations for sow feeding have seen little change in decades, despite the many ways that sows have changed dramatically in reproductive performance. Beginning in about the year 2000, sow litter size has steadily increased as a result of genetic selection. With this increase in litter number has been a steady decline in birth weight, and the resulting negative effects of lower birthweight on subsequent piglet performance. Many experiments using so-called ‘bump’ feeding, or increased energy intake in late gestation, have been conducted in attempts to arrest this decline in birthweight and piglet performance. Generally, these experiments have shown little to no improvement in birthweight and often have negative effects on sow feed intake during gestation. These experiments have ignored the fact that the energy:amino acid ratios (lysine, threonine, isoleucine, tryptophan) in late gestation are different than during early and mid-gestation. In recent research in Australia we hypothesised that rapidly increasing essential amino acid levels in late gestation would increase birth weight and potentially improve subsequent reproductive performance. Three hundred and thirty-four multiparous PIC sows (average parity 3.6, average LW 261 kg) were housed in a dynamic gestation pen after mating and randomly assigned to one of two diet regimes. Two 13.5 MJ/kg DE gestation diets were formulated and created by blending in an ESF. The Control diet contained 0.48 g SID lysine per MJ DE and SID threonine, methionine+ cysteine, isoleucine and tryptophan at 68%, 65%, 58% and18% of SID lysine and offered at 2.2kg/day from d 28 to d 110. Sow were then moved to the farrowing house and placed on a lactation diet at 3.5kg/d. The Treatment diet contained 0.55 g SID lysine/MJ DE and SID threonine, methionine+cysteine, isoleucine and tryptophan at 78%, 65%, 60% and 20% of SID lysine and offered at 2.1kg/d from d 28 to d 85 and then increased to 2.4 kg/d to d 110 d. Increasing essential amino acid levels in late gestation increased gestational weight gain (5.6 kg, P=0.004), increased total litter birth weight (1.25 kg, P=0.003), and increased the birthweight of liveborn pigs from 1.286 to 1.329 kg, (P=0.04). There was no significant effect on the total number born or born alive. Piglet performance is not available because this commercial farm practices cross-fostering. Effects of continuation of this feeding regime in the same sows during subsequent parities is currently being evaluated.

A facile one pot route for the synthesis of imide tethered peptidomimetics

2016 ◽  
Vol 14 (2) ◽  
pp. 556-563 ◽  
Author(s):  
Veladi Panduranga ◽  
Girish Prabhu ◽  
Roopesh Kumar ◽  
Basavaprabhu Basavaprabhu ◽  
Vommina V. Sureshbabu
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Efficient Method ◽  
One Pot ◽  
Protected Amino Acid

A simple and efficient method for the synthesis of N,N’-orthogonally protected imide tethered peptidomimetics is presented. The imide peptidomimetics were synthesized by coupling the in situ generated selenocarboxylate of Nα-protected amino acids with Nα-protected amino acid azides in good yields.

scholarly journals Prototypical Recombinant Multi-Protease-Inhibitor-Resistant Infectious Molecular Clones of Human Immunodeficiency Virus Type 1

2013 ◽  
Vol 57 (9) ◽  
pp. 4290-4299 ◽  
Author(s):  
Vici Varghese ◽  
Yumi Mitsuya ◽  
W. Jeffrey Fessel ◽  
Tommy F. Liu ◽  
George L. Melikian ◽  
...  
Keyword(s):  
Amino Acid ◽  
Protease Inhibitor ◽  
Cross Resistance ◽  
Amino Acid Substitutions ◽  
Phenotypic Properties ◽  
The Public ◽  
Immunodeficiency Virus ◽  
The Many ◽  
High Level ◽  
Infectious Molecular Clones

ABSTRACTThe many genetic manifestations of HIV-1 protease inhibitor (PI) resistance present challenges to research into the mechanisms of PI resistance and the assessment of new PIs. To address these challenges, we created a panel of recombinant multi-PI-resistant infectious molecular clones designed to represent the spectrum of clinically relevant multi-PI-resistant viruses. To assess the representativeness of this panel, we examined the sequences of the panel's viruses in the context of a correlation network of PI resistance amino acid substitutions in sequences from more than 10,000 patients. The panel of recombinant infectious molecular clones comprised 29 of 41 study-defined PI resistance amino acid substitutions and 23 of the 27 tightest amino acid substitution clusters. Based on their phenotypic properties, the clones were classified into four groups with increasing cross-resistance to the PIs most commonly used for salvage therapy: lopinavir (LPV), tipranavir (TPV), and darunavir (DRV). The panel of recombinant infectious molecular clones has been made available without restriction through the NIH AIDS Research and Reference Reagent Program. The public availability of the panel makes it possible to compare the inhibitory activities of different PIs with one another. The diversity of the panel and the high-level PI resistance of its clones suggest that investigational PIs active against the clones in this panel will retain antiviral activity against most if not all clinically relevant PI-resistant viruses.

EFFECT OF PERACETIC ACID OXIDATION ON N-CONTAINING COMPONENTS OF HUMIC MATERIALS

1980 ◽  
Vol 60 (3) ◽  
pp. 541-548 ◽  
Author(s):  
M. SCHNITZER ◽  
D. A. HINDLE
Keyword(s):  
Amino Acid ◽  
Peracetic Acid ◽  
Amino Sugar ◽  
Chemical Oxidation ◽  
Acid Oxidation ◽  
Mild Oxidation ◽  
Total N ◽  
Different Types ◽  
Humic Materials ◽  
Insight Into

Three humic and one fulvic acid were degraded by mild chemical oxidation with peracetic acid, with special emphasis on the effects of this type of oxidation on N-containing components. The different types of N that were considered were NH4+-N, amino acid-N, amino sugar-N, NO2−-N + NO3−-N, and by difference from total N, "unknown" N. The behaviour toward mild chemical oxidation of all four preparations was essentially similar: there were decreases in mino acid-N, amino sugar-N and "unknown" N, increases in NH4+-N, NO2−-N + NO3−-N with one material, and in N-gases. The "unknown" N was not inert. Between 16.6 and 59.1% of the latter appeared to be converted, as a result of mild chemical oxidation, to NH3 and N-gases which were expelled from the systems. The results presented provide an insight into what happens to N-containing humic components as a result of mild oxidation.

The last interglacial–glacial cycle, Clyde foreland, Baffin Island, N.W.T.: stratigraphy, biostratigraphy, and chronology

1977 ◽  
Vol 14 (12) ◽  
pp. 2824-2857 ◽  
Author(s):  
G. H. Miller ◽  
J. T. Andrews ◽  
S. K. Short
Keyword(s):  
Amino Acid ◽  
Marine Sediments ◽  
Baffin Island ◽  
Buried Soils ◽  
Last Interglacial ◽  
Pollen Assemblage ◽  
Outlet Glacier ◽  
Radiocarbon Dates ◽  
Last Glaciation

A study of the stratigraphic sequence (14C and amino acid age control), marine bivalve faunal changes, and palynology of buried soils and organic-rich sediment collected from the Clyde Foreland Formation in the extensive cliff sections of the Clyde foreland, eastern Baffin Island, N.W.T., suggests the following last interglacial – Foxe (last glaciation) glacial – present interglacial sequence.(1) Cape Christian Member (ca. 130 000 years BP?)Consists of the Sledgepointer till overlain by the Cape Christian marine sediments. In situ molluscan fauna, collected from the marine sediments, contain a moderately warm bivalve assemblage. A well-developed soil that formed on the marine sediments (Cape Christian soil) contains an interglacial pollen assemblage dominated by dwarf birch. U-series dates of > 115 000 and ca. 130 000 years BP on molluscs from the Cape Christian marine sediments suggest that they were deposited during the last interglaciation, here termed the Cape Christian Interglaciation. The development of a subarctic pollen assemblage in the Cape Christian soil has not been duplicated during the present interglaciation, suggesting higher summer temperatures and perhaps a duration well in excess of 10 000 years for the last interglaciation.(2) Kuvinilk MemberConsists of fossiliferous marine sediments, locally divided by the Clyde till into upper and lower units. The Clyde till was deposited by the earliest and most extensive advance of the Foxe (last) Glaciation. Kuvinilk marine sediments both under- and overlying the Clyde till contain the pecten Chlamys islandicus, indicating that the outlet glacier advanced into a subarctic marine environment. Amino acid ratios from in situ pelecypod shells abovę and below the Clyde till are not statistically different, but contrast markedly with ratios obtained from the same species in the Cape Christian Member. Organic horizons within the Kuvinilk marine sediments contain a relatively rich pollen assemblage, although 'absolute' counts are low.(3) Kogalu Member (> 35 00014C years BP)Sediments of the Kogalu Member unconformably overlie those of the Kuvinilk Member, but are of a similar character. The dominant sediments are marine in origin, but in places are divided into upper and lower units by the Ayr Lake till. Amino acid ratios from in situ shells above and below the Ayr Lake till are indistinguishable, but substantially less than those in the Kuvinilk Member, suggesting the two members are separated by a considerable time interval. Radiocarbon dates on shells in the Kogalu marine sediments range from 33 000 to 47 700 years BP, but these may be only minimum estimates. The sea transgressed to a maximum level 70–80 m asl, coincident with the glacial maximum. Subarctic marine fauna of interstadial–interglacial character occur within the Kogalu marine sediments.(4) Eglinton Member (10 000 years BP to present)A major unconformity exists between the Kogalu and Eglinton Members. Ravenscraig marine sediments were deposited during an early Holocene marine transgression–regression cycle; the oldest dates on these sediments are ca. 10 000 years BP. Locally a vegetation mat occurs at the base or within the Ravenscraig unit. Pollen from these beds is sparse, but indicates a terrestrial vegetation assemblage as diverse as that of today. There is no evidence that Laurentide Ice reached the foreland during the last 30 000 years. Eolian sands that overlie a soil developed on the marine sediments record a late Holocene climatic deterioration. Pollen in organic-rich sediments at the base of, and within, the eolian sands record a vegetation shift in response to climatic change.

Synthetic Strategies for the Modification of Diclofenac

Synlett ◽  
2017 ◽  
Vol 28 (15) ◽  
pp. 1984-1989 ◽  
Author(s):  
Rudolf Schneider ◽  
Stephan Schmidt ◽  
Sven Hanelt ◽  
Carsten Canitz ◽  
Holger Hoffmann ◽  
...  
Keyword(s):  
Amino Acid ◽  
Solid Phase ◽  
Free Acid ◽  
Protein A ◽  
Sensor Applications ◽  
Protein Conjugates ◽  
Lysine Residues ◽  
Sufficient Distance ◽  
Direct Binding

For many heterogeneous sensor applications as well as the synthesis of hapten antigens to produce antibodies, protein conjugates of the target substance are essential. A requirement is that the target substance already offers or is modified to contain a functionality that allows for coupling to a protein, that is, an amino acid residue. Ideally, to avoid shielding of the compound by the carrier protein, a sufficient distance to the protein surface should be provided. With its carboxyl function diclofenac (DCF) allows for direct binding to lysine residues after in situ synthesis of the NHS ester. One problem is that diclofenac as free acid tends to autocondensation, which results in low yields. Here we describe the ‘insertion’ of a C6 spacer via synthesis of the amide with 6-aminohexanoic acid. To carry out the reaction in solution, first the methyl ester of the amino acid had to be produced. Due to otherwise low yields and large cleaning efforts, solid-phase synthesis on Fmoc Ahx Wang resin is recommended. The crude product is mainly contaminated by cleavage products from the resin which were removed by chromatography. The structure of the highly pure hapten was completely determined by nuclear magnetic resonance (NMR) spectroscopy.

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