We studied in details the ammonia or free amino acids (AA) effects on proteolytic activity of three ruminal bacteria: enzymatic activities and protein breakdown products were measured at the end of the exponential growth phase. In Streptococcus bovis the simultaneous uptake of ammonia and probably small peptides induced a decline ...

The capabilities of genome-scale metabolic networks can be described through the determination of a set of systemically independent and unique flux maps called extreme pathways. The first study of genome-scale extreme pathways for the simultaneous formation of all nonessential amino acids or ribonucleotides in Helicobacter pylori is presented. Three key ...

Besides being an indispensable amino acid for protein synthesis, arginine (Arg) is also involved in a number of other physiological functions. Available data on the quantitative requirement for Arg in different teleosts appear to show much variability. So far, there are very limited data on the maintenance requirements of indispensable ...

The allocation of nutritional resources to reproduction in animals is a complex process of great evolutionary significance. We use compound-specific stable isotope analysis of carbon (GC/combustion/isotope ratio MS) to investigate the dietary sources of egg amino acids in a nectar-feeding hawkmoth. Previous work suggests that the nutrients used in egg ...

AIMS: To study the effect of combined continuous veno-venous hemodiafiltration (CVVHDF) and high (2.5 g/kg/day) parenteral amino acid supplementation on nitrogen balance, amino acid losses and azotemic control in a cohort of patients with severe acute renal failure (ARF). METHODS: We administered 2.5 grams/kg/day of amino acids intravenously to seven ...

This article discusses how nitrate assimilation is integrated with nitrate uptake, with ammonium assimilation and amino acid synthesis, with pH regulation, and with the sugar supply in tobacco leaves. During the first part of the light period, nitrate assimilation exceeds nitrate uptake by 2-fold and ammonium assimilation by 50%, leading ...

We investigated whether a qualitative manipulation of amino acid mixture could improve the nutritional status of patients undergoing surgery. Patients received total parenteral nutrition for 2 consecutive 5-day periods. Energy and nitrogen supplies were calculated using a modified Harris-Benedict equation, with an energy-to-nitrogen ratio of 125 kcal/g nitrogen (N). The ...

The product ion mass spectra (collisionally induced dissociation mass spectra) of 12 different cyclosporins modified at every N-methylated amino acid residue with respect to cyclosporin A were compared and the effect of N-demethylation on ring opening mechanisms was evaluated. The four preferential protonation sites were identified in [MeBmt(1)]-cyclosporins. Three sites ...

Considering that amino acids constitute an important energy fuel during early life of the Atlantic halibut (Hippoglossus hippoglossus L.), it is of interest to understand how the nitrogenous end products are handled. In this study we focused on the kinetics and fates of ammonia, urea and uric acid. The results ...

It has traditionally been thought that animals can utilize ammonia for amino acid biosynthesis, and that for them some amino acids are nutritionally nonessential. Presumably this idea originates from the notions of Schoenheimer (G. L. Foster et al. [1939] J. Biol. Chem. 127, 319-327) and of Rose (W. C. Rose ...

BACKGROUND: Early administration of parenteral amino acids to infants with extremely low birth weight (birth weight < or = 1,000 g) has been encouraged to foster growth. However, excessive intravenous intake of amino acids may cause metabolic acidosis and uremia in extremely low birth weight infants. The hypothesis for this ...

Reactive oxygen species are reactive, partially reduced derivatives of molecular oxygen (O 2 ). Important reactive oxygen species in biologic systems include superoxide radical anion, hydrogen peroxide, and hydroxyl radical. Closely related species include the hypohalous acids, particularly hypochlorous acid; chloramine and substituted chloramines; and singlet oxygen. Reactive nitrogen species ...

PURPOSE: We studied the effects of an amino acid mixture used for total parenteral nutrition (TPN) in pediatrics, on the liver function test results (LFTs) of neonates. METHODS: Thirty neonatal surgical patients were randomly divided into three groups according to the dose of amino acids given: group H ( n ...

This paper examines the evolution of nitrogen compounds during alcoholic fermentation in chardonnay musts inoculated with killer strains of Saccharomyces cerevisiae (ICV D47 and ICV K1M). The results are compared with those obtained from chardonnay must fermented with indigenous yeasts (control sample). The total quantity of nitrogen assimilated, as well ...

Whole ungutted pota and octopus were stored in bulk in stainless steel refrigerated containers under controlled atmospheres. In order to evaluate the effectiveness of this treatment, physicochemical tests (pH, trimethylamine nitrogen, total volatile basic nitrogen, 2-thiobarbituric acid) and sensory assessments (inspection) were done. For both pota and octopus, the control ...

AIMS: Optimization of bacteriocin production by L. lactis subsp. lactis CECT 539 and Ped. acidilactici NRRL B-5627 on mussel-processing wastes. METHODS AND RESULTS: The concentrations of glucose and five nitrogen sources that optimize nisin and pediocin production were determined using a second order orthogonal factorial design. NH4Cl, glycine and glutamic ...

Trichloroacetic acid (TCA) can be found in various environmental compartments like air, rain and plants all over the world. It is assumed that TCA is an atmospheric degradation product of volatile chloroorganic hydrocarbons. The herbicide effect of TCA in higher concentrations is well known, but not much is known about ...

Somatotropin (ST) treatment promotes animal growth and allows for the conservation of amino acids by increasing nitrogen retention and reducing ureagenesis and amino acid oxidation. To determine whether the improvement in amino acid conservation with ST treatment involves regulation of urea cycle enzyme activities in both liver and intestine, growing ...

The aim of the research was to evaluate the content of amino acids in the needles of Pinus sylvestris growing in the area affected by a nitrogen fertilizer factory and to compare them with other parameters of needles, trees, and sites. Three young-age stands of Scots pine were selected at ...

BACKGROUND & AIMS: Both recombinant human growth hormone (rhGH) and glutamine (GLN) may have beneficial anabolic actions on amino acid metabolism. The aim of this study was to evaluate the additive effects of rhGH and GLN on plasma amino acids postoperatively. METHODS: 31 females undergoing laparoscopic cholecystectomy were randomized to ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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% ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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. ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...

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 ...