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Results 451 - 500 of 1204
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Ohlund J - - 2001
Effects of organic and inorganic nitrogen sources on growth and mineral nutrient concentrations of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karst.) seedlings were compared in a 100-day experiment in a greenhouse. Seedlings were grown in pots containing peat. Nutrient solutions differing in ammonium, nitrate, arginine ...
Singer M A - - 2001
In mammals, varying in size from mouse to elephant there is a close linkage between metabolic rate (MR) and glomerular filtration rate (GFR). This linkage has evolved because of the necessity to excrete nitrogenous wastes generated predominately by amino acid catabolism. A similar linkage is observed in birds, reptiles and ...
Guerra N P - - 2001
The ability of Lactococcus lactis subsp. lactis CECT 539 and Pediococcus acidilactici NRRL B-5627 to produce bacteriocins on both diluted and concentrated whey was investigated in batch fermentations. Both strains produced the higher amounts of biomass and bacteriocin titres on diluted whey. Luedeking and Piret expression was able to model ...
Hong D - - 2001
An experiment was conducted using the TMEn bioassay method to investigate the additivity and associative effects of metabolizable energy and amino acid digestibility in barley and canola meal for White Pekin ducks. Additivity was tested by comparing the difference between observed values determined in a complete diet and predicted values ...
Yamauchi Masayoshi - - 2001
Previous studies have shown that nocturnal glucose supplementation and a late evening meal reduced raised protein turnover rates and led to a better nitrogen balance in patients with cirrhosis. In this study, we investigated whether or not oral branched chain amino acid (BCAA) supplementation in the late evening would improve ...
Breitkreutz R - - 2001
Increased whole-body proteolysis with muscle protein net degradation has been suggested as one of the causes of weight loss in patients infected with human immunodeficiency virus (HIV). We studied the exchange rates of amino acids and energy substrates across the lower extremity in 16 HIV patients and 16 age-matched controls ...
Abbt-Braun G - - 2001
The sulfur compounds of refractory organic substances (ROS) of different origin have been characterized. Total organic sulfur was determined by elemental analysis. Sulfur-containing amino acids methionine and cystine were analyzed chromatographically after hydrolysis with HCl or by proteolytic digestion using enzymes. The results obtained from elemental analysis show that the ...
Caputo C - - 2001
Grain protein content is one of the major determinants of the baking and nutritional quality of wheat. It has previously been reported that the ditelosomic line of wheat (Triticum aestivum L.) CSDT7BL, where the short arm of chromosome 7B is missing, shows a lower grain protein concentration than the normal ...
Voelker F - - 2001
Phosphate-limited synthetic culture media were designed to investigate the growth and the pristinamycin production of 'Streptomyces pristinaespiralis' using different nitrogen sources. During balanced growth, either mineral or organic nitrogen sources were readily utilized. However, glutamate and alanine were used as both nitrogen and carbon source, sparing the utilization of the ...
Sicinska D - - 2001
Nitrogen kinetic isotope effects on the decarboxylation of 4-pyridylacetic acid have been measured in solvents of different polarity and have been found to vary from the inverse value of 0.994 to the normal value of 1.002 upon increase of water content of the binary dioxane--water solvent from 25% to 75% ...
Malaguti D - - 2001
Nitrogen is remobilized from storage for the growth of Malus domestica leaves each spring. Seasonal patterns of N translocation in the xylem sap as a consequence of remobilization were determined in 2-year-old 'Golden delicious' trees grafted on M9 rootstocks. The trees were grown in sand culture and (15)NH(4)(15)NO(3) at 10.4 ...
Vargas-García M C - - 2001
The capacity of 4-hydroxybenzoic acid to support exopolysaccharide (EPS) biosynthesis was investigated. Carbon source concentration, nitrogen supplementation, and other nutritional and environmental factors were optimized to obtain maximal EPS recovery. Higher EPS yields were obtained in nitrogen-free media amended with 20-30 mM 4-hydroxybenzoic acid. In general, modifications in inorganic salt ...
Mauricio J C - - 2001
Urea, ammonium, and free amino acid contents were quantified in a must from Vitis vinifera cv. Pedro Ximenez grapes and in fermented wine and after a short aging of this wine by Saccharomyces cerevisiae race capensis yeast under variable oxygen availability conditions. The previous compounds were also determined in a ...
Liu J W - - 2001
The potential feedback by intracellular nitrogen pools on maximum N uptake (NH4+) rate were determined for Gracilaria tenuistipitata var. liui and Ulva pertusa. The results of correlation matrix analyzing showed that the surge uptake of ammonium seemed related to rapid changes in small intracellular pools of inorganic nitrogen or small ...
Soden D M - - 2001
Four laccase isozyme genes, Psc lac1, 2, 3 and 4 have been cloned from the edible mushroom, Pleurotus sajor-caju. The genes display a high degree of homology with other basidiomycete laccases (55-99%) at the amino acid level. Of the laccase genes isolated, Psc lac1 and 4 displayed the highest degree ...
Liu J W - - 2001
This paper deals with the N storage of Gracilaria tenuistipitata var. liui and Ulva pertusa under ammonium enrichment and starvation. After 10 days of ammonium enrichment, ammonium NH4+, free amino acid (FAA), protein (pro), chlorophyll (Chl), phycoerythrin (PE) and total dissolved nitrogen (TDN) of the two macroalgae increased significantly. Total ...
Atasoglu C - - 2001
The origin of cell nitrogen and amino acid nitrogen during growth of ruminal cellulolytic bacteria in different growth media was investigated by using (15)NH(3). At high concentrations of peptides (Trypticase, 10 g/liter) and amino acids (15.5 g/liter), significant amounts of cell nitrogen of Fibrobacter succinogenes BL2 (51%), Ruminococcus flavefaciens 17 ...
Engel E - - 2001
The aim of this study was to add to the understanding of changes in taste that occur during the ripening of a bitter Camembert cheese by the evolution of its composition. Physicochemical analyses were performed on rind, under-rind, and center portions of a Camembert cheese selected for its intense bitterness. ...
Solomon P S - - 2001
To address the problem of the nutritional requirements of phyto-pathogenic fungi growing in planta, the environment for the intercellular biotrophic pathogen, Cladosporium fulvum Cooke, of tomato (Lycopersicon esculentum Mill.) was analysed. Using a novel technique for infiltrating the intercellular space, we measured the concentrations of 21 amino acids, nitrate and ...
Donnelly M - - 2001
Density functional calculations using hybrid functionals (B3LYP) have been performed to study the mechanism of the autocatalytic posttranslational cyclization observed in histidine ammonia-lyase. Two mechanisms were analyzed, the commonly accepted mechanism in which cyclization precedes dehydrogenation (reduced mechanism) and a mechanism in which dehydrogenation precedes cyclization (oxidized mechanism). The reduced ...
Lim C B - - 2001
This study was designed to elucidate the strategies adopted by mudskippers to handle endogenous ammonia during aerial exposure in constant darkness. Under these conditions, specimens exhibited minimal locomotory activity, and the ammonia and urea excretion rates in both Periophthalmodon schlosseri and Boleophthalmus boddaerti decreased significantly. As a consequence, ammonia accumulation ...
Rosenfeld P E - - 2001
Odor emissions and microbial activity associated with biosolids dewatered using seven different polyacrylamide cationic polymers were investigated. Nitrogen, sulfur, ketone, and odor unit emissions, and biosolids microbial community metabolic profiles were measured for biosolids containing each polymer. Ammonia represented more than 98% of total nitrogen flux for all polymers, with ...
Perttilä S - - 2001
1. Effects of preservation method (drying or air-tight storage of whole grain and ensiling of rolled high-moisture grain) and beta-glucanase supplementation (Econase) on apparent ileal amino acid digestibilities and metabolisable energy content of barley were evaluated with Ross broiler chickens. In addition, the effect of barley preservation method was assessed ...
Calvente V - - 2001
The production of rhodotorulic acid, a siderophore synthesized by Rhodotorula strains, was improved with the objective of achieving the biocontrol of phytopathogenic moulds. Rhodotorulic acid increased up to 60% in the presence of urea as a nitrogen source, pH near to 8 and a C:N ratio of 8:1. The siderophore-containing ...
Xu J - - 2001
AIMS: To examine the hypothesis of non-immune defence mechanisms based on nitrite. METHODS AND RESULTS: The acidified media (nutrient broth or citrate-phosphate buffer) under aerobic conditions with additions of physiological levels of nitrite, L-ascorbic acid, iodide and thiocyanate were used to simulate gastric juice. The bactericidal effects of acidified nitrite ...
Gürü M - - 2001
Production of oxalic acid from sugar beet molasses was developed in a series of three reactors. Nitrogen oxides formed were used to manufacture oxalic acid in the second and third reactor. Parameters affecting the reaction were determined to be, air flow rate, temperature, the amount of V2O5 catalyst and the ...
Todd C D - - 2001
After seed germination, hydrolysis of storage proteins provides a nitrogen source for the developing seedling. In conifers the majority of these reserves are located in the living haploid megagametophyte tissue. In the developing loblolly pine (Pinus taeda L.) seedling an influx of free amino acids from the megagametophyte accompanies germination ...
Pötter M - - 2001
Poly(gamma-D-glutamic acid) (PGA)-producing strains of Bacillus species were investigated to determine their ability to contribute to reducing the amount of ammonium nitrogen in liquid manures and their ability to convert some of the ammonium into this polyamino acid as a transient depot for nitrogen. Organisms that do these things should ...
Teixidó J - - 2001
Hydrolysis of the amino groups in condensed 2,4-diaminopyrimidine systems (1) has been used as a common method for the synthesis of oxo-substituted pyrimidines. In particular, the treatment with 6 M HCl usually yields exclusively the 2-amino-4-oxopyrimidine isomer (2). During our work, we found that the hydrolysis of the amino groups ...
Nordin A - - 2001
Cycling of soluble non-protein N compounds is thought to be indicative of the N-nutritional status of trees. We determined the major N forms in bark, wood and foliage and estimated the dependence of prevalent N forms on N availability in Pinus sylvestris L. trees from northern Sweden. Trees subjected to ...
Busch G - - 2001
A global assessment of the impact of the anthropogenic perturbation of the nitrogen and sulfur cycles on forest ecosystems is carried out for both the present-day [1980-1990] and for a projection into the future [2040-2050] under a scenario of economic development which represents a medium path of development according to ...
da Silva M C - - 2001
The structural complexity of the nitrogen sources strongly affects biomass production and secretion of hydrolytic enzymes in filamentous fungi. Fusarium oxysporum and Aspergillus nidulans were grown in media containing glucose or starch, and supplemented with a nitrogen source varying from a single ammonium salt (ammonium sulfate) to free amino acids ...
Sommerville K - - 2001
Dissolved combined amino acids (DCAA) are important constituents of the dissolved organic nitrogen (DON) pool in marine environments, although little is known about their sources, dynamics and sinks. The DCAA pool consists of various compounds including proteins and peptides, proteins linked to sugars and amino acids adsorbed to humic and ...
Gouda M K - - 2001
Poly(hydroxybutyric acid) (PHB) and other biodegradable polyesters are promising candidates for the development of environment-friendly, totally biodegradable plastics. The use of cane molasses and corn steep liquor, two of the cheapest substrates available in Egypt, may help to reduce the cost of producing such biopolyesters. In this work, the effect ...
Dehbi F - - 2001
Pseudomonas syringae pv. tabaci, the causal agent of the wildfire of tobacco, produces the phytotoxin tabtoxin. The effects of carbon, nitrogen sources and amino acids on growth and tabtoxin production by pv. tabaci, were examined by varying the components of a defined basal medium, which contained the following nutrients per ...
Koike Y - - 2001
The influence of the consumed carbon to nitrogen (C/N) ratio on arachidonic acid (AA) production and mycelial morphology was investigated in cultures of Mortierella alpina using shake flasks and a fermentor. The consumed C/N ratio was varied from 5 to 32 under the condition that the total initial amount of ...
Rosenthal G A - - 2001
L-Canavanine, L-2-amino-4-(guanidinooxy)butyric acid, is a potentially toxic nonprotein amino acid of certain leguminous plants. Many species are prolific canavanine producers; they divert enormous nitrogen resource to the storage of this single natural product. Canavanine, a highly effective protective allelochemical, provides a formidable chemical barrier to predation and disease. The accumulated ...
Jia M - - 2001
A simple and reliable method for the determination of NH4+, K+, Na+, aspartic acid, asparagine, glutamine, and alanine by ion chromatography has been developed. It is suitable for monitoring changes of nitrogen metabolism in soybean because it can accurately measure concentrations o asparagine and NH4+, two key substances for nitrogen ...
Thureen P J - - 2000
We studied the effect of an acute 4-h period of hyperinsulinemia (H) on net utilization rates (AAUR(net)) of 21 amino acids (AA) in 17 studies performed in 13 late-gestation fetal sheep by use of a novel fetal hyperinsulinemic-euglycemic-euaminoacidemic clamp. During H [84 +/- 12 (SE) microU/ml H, 15 +/- 2 ...
Olson M E - - 2000
The objective of the study was to determine the influence of either oral or intramuscular administration of stanozolol on nitrogen retention in dogs by using a non-invasive 15N-amino acid tracer technique. Ten healthy, intact, adult male sled dogs received either stanozolol tablets, 2 mg/dog PO, q12h, for 25 days (Group ...
Mariotti F - - 2000
BACKGROUND: Sucrose exerts a sparing effect on whole-body protein metabolism, mainly during the absorptive phase. OBJECTIVE: We aimed to characterize the acute postprandial effect of addition of sucrose on deamination of dietary and endogenous nitrogen, with particular consideration being given to the effects of bioavailability. DESIGN: Twenty-one subjects equipped with ...
De Cian M - - 2000
The distribution of nitrogen metabolism end-products and the associated enzyme activities, free amino acids and purine base catabolites were investigated in all the body compartments (circulating fluids and tissues) of the hydrothermal vent tubeworm Riftia pachyptila to acquire a general overview of nitrogen metabolism in this symbiotic organism. There were ...
Ells B - - 2000
A combination of electrospray ionization, high-field asymmetric waveform ion mobility spectrometry, and mass spectrometry (ESI-FAIMS-MS) was used for the analysis of a solution containing a mixture of the nine chlorinated and brominated haloacetic acids. For a carrier gas of nitrogen in the FAIMS analyzer, haloacetate anions of the mono- and ...
Wolthers T - - 2000
BACKGROUND/AIMS: Glucocorticoids upregulate hepatic urea synthesis and cause protein breakdown to prevail over synthesis, releasing amino acids into the blood stream and increasing the substrate supply for hepatic urea synthesis. Budesonide is a new generation glucocorticoid that may be used for treatment of inflammatory diseases, e.g. Crohn's disease and autoimmune ...
Jyothi B - - 2000
A freshwater cat fish was exposed to sublethal concentrations of two pesticides--carbaryl, a carbamate and phorate, an organophosphorus pesticide for 24, 72, 120 and 168 hr. The alterations in the serum profile of non protein nitrogen compounds demonstrated an increase in urea, uric acid and creatinine throughout the experimental period.
Barra M - - 2000
The thermal cis-to-trans isomerization of 1,3-diphenyltriazene (DPT) has been investigated in buffered aqueous solutions by means of laser-flash photolysis techniques. The cis-to-trans isomerization process is found to be catalyzed by general acids and general bases as a result of acid/base-promoted 1,3-prototropic rearrangements. Acid catalysis is attributed to rate-limiting proton transfer ...
Winters A L - - 2000
A study was carried out on the changes occurring in the amino acid fraction of a hybrid ryegrass during ensilage in laboratory-scale silos to help to establish the relative roles of plant and microbial proteases on protein degradation in the silo. Herbage treatments included (i) normal grass without treatment (ii) ...
Leclercq-Perlat M N - - 2000
Model smear soft cheeses, prepared with Debaryomyces hansenii and Brevibacterium linens as ripening starters, were ripened under aseptic conditions. Results of the cheese-making trials, in triplicate, were similar and showed similar patterns of protein degradation. In all of the trials, the acid-soluble nitrogen and nonprotein nitrogen (NPN) indexes and NH3 ...
Evans C D - - 2000
The South Pennines, an area of acid-sensitive geology at the centre of a major industrial region, have undergone perhaps the most severe historic exposure to sulphur and nitrogen deposition in the UK. This study addresses a lack of existing research on the region by presenting the findings of a survey ...
Choi D B - - 2000
To examine what causes increased viscosity in culture broth in Streptomyces fradiae culture, various natural nitrogen sources were investigated. Extracellular protease activity increased with culture time and decomposed the natural nitrogen source into amino acids. In the case of gluten meal, after a culture time of 5 d, concentrations of ...
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