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Sample records for digestibility nitrogen metabolism

  1. Nutrient digestibility and nitrogen metabolism in West African dwarf ...

    African Journals Online (AJOL)

    An experiment was conducted to determine nutrient digestibility and nitrogen metabolism in sheep fed differently processed breadfruit meal. Twenty West African dwarf sheep with mean weight body of 6.00 ± 0.55kg were randomly allotted to four dietary treatments with five sheep per treatment in a completely randomised ...

  2. Total mixed ration in exercising horse: digestibility and nitrogen metabolism

    Directory of Open Access Journals (Sweden)

    L. Magni

    2010-04-01

    Full Text Available The aim of this study was to evaluate the apparent digestibility of a total mixed ration (TMR versus a traditional mixed hay/cereals diet. Four adult trained Standardbred geldings – BW = 478±37 kg - were used. The two diets consisted of 20 kg of a commercial TMR - corn silage, alfalfa hay, wet brewers’ grain, oat, apple pomace, molasses cane, soybean oil and mineral/vitamin supplement - (Diet 1 or 7 kg of meadow hay and 4.5 kg of cereal-mix - corn, oat, barley and protein/mineral/vitamin supplement - (Diet 2. The trial was conducted according to a Latin Square design (2x2. After an adaptation period of four weeks, total faeces and urine were collected for 6 days. Both feed and faeces samples were analysed for DM, OM, CP, EE, CF, NDF, ADF, cellulose, hemicellulose, ADL and GE. Data were analysed by ANOVA. The apparent digestibility and nitrogen balance of the two diets were compared. DM, OM, CP and GE apparent digestibility were significantly different between the diets, with higher values for unifeed diet than traditional diet. Energy requirement was satisfied by both diets (96.54 vs 95.55 MJ. Nitrogen balance showed negative values in both diets (- 61.67 vs - 9.05, but the hay/cereals supplemented diet showed the best protein utilisation.

  3. Digestion and nitrogen metabolism of grass fed dairy cows

    NARCIS (Netherlands)

    Vuuren, van A.M.

    1993-01-01

    Until recently, young, highly digestible grass was considered an ideal feed for dairy cows. However, research during the last decades has shown that the nutrient supply of grazing animals is insufficient for milk productions above c. 29 kg per day. Experiments in England and New Zealand

  4. Nitrogen metabolism of the intestine during digestion in a teleost fish, the plainfin midshipman (Porichthys notatus).

    Science.gov (United States)

    Bucking, Carol; LeMoine, Christophe M R; Craig, Paul M; Walsh, Patrick J

    2013-08-01

    Digestion affects nitrogen metabolism in fish, as both exogenous and endogenous proteins and amino acids are catabolized, liberating ammonia in the process. Here we present a model of local detoxification of ammonia by the intestinal tissue of the plainfin midshipman (Porichthys notatus) during digestion, resulting in an increase in urea excretion of gastrointestinal origin. Corroborating evidence indicated whole-animal ammonia and urea excretion increased following feeding, and ammonia levels within the lumen of the midshipman intestine increased to high levels (1.8±0.4 μmol N g(-1)). We propose that this ammonia entered the enterocytes and was detoxified to urea via the ornithine-urea cycle (O-UC) enzymes, as evidenced by a 1.5- to 2.9-fold post-prandial increase in glutamine synthetase activity (0.14±0.05 and 0.28±0.02 μmol min(-1) g(-1) versus 0.41±0.03 μmol min(-1) g(-1)) and an 8.7-fold increase in carbamoyl phosphate synthetase III activity (0.3±1.2 versus 2.6±0.4 nmol min(-1) g(-1)). Furthermore, digestion increased urea production by isolated gastrointestinal tissue 1.7-fold, supporting our hypothesis that intestinal tissue synthesizes urea in response to feeding. We further propose that the intestinal urea may have been excreted into the intestinal lumen via an apical urea transporter as visualized using immunohistochemistry. A portion of the urea was then excreted to the environment along with the feces, resulting in the observed increase in urea excretion, while another portion may have been used by intestinal ureolytic bacteria. Overall, we propose that P. notatus produces urea within the enterocytes via a functional O-UC, which is then excreted into the intestinal lumen. Our model of intestinal nitrogen metabolism does not appear to be universal as we were unab le to activate the O-UC in the intestine of fed rainbow trout. However, literature values suggest that multiple fish species could follow this model.

  5. Influence of diet and microbial activity in the digestive tract on digestibility, and nitrogen and energy metabolism in rats and pigs

    DEFF Research Database (Denmark)

    Eggum, B O; Thorbek, G; Beames, R M

    1982-01-01

    -55 kg. Measurements were made on the influence of microbial activity in the digestive tract on digestibility and nitrogen and energy metabolism. Dietary inclusion of the antibiotic Nebacitin was the method used to reduce the microbial population. 2. The microbial activity in the hind-gut (mumol ATP....../g air-dry contents) of antibiotic-treated rats was reduced to approximately one-tenth of that of untreated rats. 3. Live-weight gain was not significantly affected in either species by a reduction in the microbial activity, in spite of a reduction in dry matter digestibility in animals with reduced...... microflora. 4. For rats on low-crude-fibre diets, a reduction in microflora reduced digestibility of all nutrients and energy and metabolizability of digestible energy by approximately 5.4%. All differences were highly significant. On high-crude-fibre diets the decrease was approximately 5.9%. In pigs...

  6. Intake, digestibility, and rumen and metabolic characteristics of cattle fed low-quality tropical forage and supplemented with nitrogen and different levels of starch.

    Science.gov (United States)

    de Oliveira Franco, Marcia; Detmann, Edenio; de Campos Valadares Filho, Sebastião; Batista, Erick Darlisson; de Almeida Rufino, Luana Marta; Barbosa, Marcília Medrado; Lopes, Alexandre Ribeiro

    2017-06-01

    Effects of nitrogen supplementation associated with different levels of starch on voluntary intake, digestibility, and rumen and metabolic characteristics of cattle fed low-quality tropical forage ( Brachiaria decumbens hay, 7.4% crude protein, CP) were evaluated using ruminal and abomasal cannulated steers. Five European×Zebu young bulls (186 kg body weight, BW) were distributed according to a 5×5 Latin square. The following treatments were evaluated: control, supplementation with 300 g CP/d (0:1), supplementation with 300 g starch/d and 300 g CP/d (1:1), supplementation with 600 g starch/d and 300 g CP/d (2:1), and supplementation with 900 g starch/d and 300 g CP/d (3:1). A mixture of nitrogenous compounds provided 1/3 from true protein (casein) and 2/3 from non-protein nitrogen (mixture of urea and ammonium sulphate, 9:1) was used as the nitrogen supplement. In order to supply energy a unique source of corn starch was used. Supplements increased (p0.05) forage intake. There was a cubic effect (pdigestibility, but did not affect (p>0.05) neutral detergent fibre corrected for ash and protein (NDFap) digestibility. There was a positive linear effect (pdigestibility. Total NDFap digestibility was not affected (p>0.05) by the amount of supplemental starch. Ruminal ammonia nitrogen concentrations were higher (p<0.05) in supplemented animals, however, a negative linear effect (p<0.05) of amount of starch was observed. Supplements increased (p<0.05) the nitrogen balance (NB) and efficiency of nitrogen utilization. These effects were attributed to increased body anabolism, supported by higher (p<0.05) serum concentration of insulin-like growth factor 1. Increasing the amount of starch tended (p<0.06) to linearly increase the NB. In spite of this, there was a highest NB value for the 2:1 starch:CP ratio amongst the treatments with supplementation. Nitrogen supplementation in cattle fed low-quality tropical forage increases nitrogen retention in the animal's body. An

  7. Effect of replacing ground corn and soybean meal with licuri cake on the performance, digestibility, nitrogen metabolism and ingestive behavior in lactating dairy cows.

    Science.gov (United States)

    Ferreira, A C; Vieira, J F; Barbosa, A M; Silva, T M; Bezerra, L R; Nascimento, N G; de Freitas, J E; Jaeger, S M P L; Oliveira, P de A; Oliveira, R L

    2017-11-01

    Licuri (Syagrus coronate) cake is a biodiesel by-product used in ruminant feed as a beneficial energy source for supplementation in managed pastures. The objective was to evaluate the performance, digestibility, nitrogen balance, blood metabolites, ingestive behavior and diet profitability of eight crossbred Holstein (3/4)×Gyr (5/8) multiparous cows (480±25 kg BW and 100 days milking) grazing and supplemented with licuri cake partially replacing ground corn and soybean meal in concentrate (0, 200, 400 and 600 g/kg in dry matter (DM)), distributed in an experimental duplicated 4×4 Latin square design. Licuri cake partially replacing ground corn and soybean meal increased (Pdairy cows with average productions of 10 kg/day at levels up to 400 g/kg in the concentrate supplement because it provides an additional profit of US$0.07/animal per day and increased milk and Minas frescal cheese fat without negative effects on productive parameters.

  8. Effects of varying ruminally undegradable protein supplementation on forage digestion, nitrogen metabolism, and urea kinetics in Nellore cattle fed low-quality tropical forage.

    Science.gov (United States)

    Batista, E D; Detmann, E; Titgemeyer, E C; Valadares Filho, S C; Valadares, R F D; Prates, L L; Rennó, L N; Paulino, M F

    2016-01-01

    Effects of supplemental RDP and RUP on nutrient digestion, N metabolism, urea kinetics, and muscle protein degradation were evaluated in Nellore heifers () consuming low-quality signal grass hay (5% CP and 80% NDF, DM basis). Five ruminally and abomasally cannulated Nellore heifers (248 ± 9 kg) were used in a 5 × 5 Latin square. Treatments were the control (no supplement) and RDP supplementation to meet 100% of the RDP requirement plus RUP provision to supply 0, 50, 100, or 150% of the RUP requirement. Supplemental RDP (casein plus NPN) was ruminally dosed twice daily, and RUP supply (casein) was continuously infused abomasally. Jugular infusion of [NN]-urea with measurement of enrichment in urine was used to evaluate urea kinetics. The ratio of urinary 3-methylhistidine to creatinine was used to estimate skeletal muscle protein degradation. Forage NDF intake (2.48 kg/d) was not affected ( ≥ 0.37) by supplementation, but supplementation did increase ruminal NDF digestion ( Urea entry rate and gastrointestinal entry rate of urea were increased by supplementation ( urea entry rate and tended ( = 0.07) to linearly increase gastrointestinal entry rate of urea. Urea use for anabolic purposes tended ( = 0.07) to be increased by supplementation, and RUP provision also tended ( = 0.08) to linearly increase the amount of urea used for anabolism. The fraction of recycled urea N incorporated into microbial N was greater ( urea from the renal tubule than did supplemented heifers. Overall, unsupplemented heifers had greater mobilization of AA from myofibrillar protein, which provided N for urea synthesis and subsequent recycling. Supplemental RUP, when RDP was supplied, not only increased N retention but also supported increased urea N recycling and increased ruminal microbial protein synthesis.

  9. Effect of the Ratio of Non-fibrous Carbohydrates to Neutral Detergent Fiber and Protein Structure on Intake, Digestibility, Rumen Fermentation, and Nitrogen Metabolism in Lambs.

    Science.gov (United States)

    Ma, T; Tu, Y; Zhang, N F; Deng, K D; Diao, Q Y

    2015-10-01

    This study aimed to investigate the effect of the ratio of non-fibrous carbohydrates to neutral detergent fibre (NFC/NDF) and undegraded dietary protein (UDP) on rumen fermentation and nitrogen metabolism in lambs. Four Dorper×thin-tailed Han crossbred lambs, averaging 62.3±1.9 kg of body weight and 10 mo of age, were randomly assigned to four dietary treatments of combinations of two levels of NFC/NDF (1.0 and 1.7) and two levels of UDP (35% and 50% of crude protein [CP]). Duodenal nutrient flows were measured with dual markers of Yb and Co, and microbial N (MN) synthesis was estimated using (15)N. High UDP decreased organic matter (OM) intake (p = 0.002) and CP intake (p = 0.005). Ruminal pH (p<0.001), ammonia nitrogen (NH3-N; p = 0.008), and total volatile fatty acids (p<0.001) were affected by dietary NFC/NDF. The ruminal concentration of NH3-N was also affected by UDP (p<0.001). The duodenal flow of total MN (p = 0.007) was greater for lambs fed the high NFC/NDF diet. The amount of metabolisable N increased with increasing dietary NFC:NDF (p = 0.02) or UDP (p = 0.04). In conclusion, the diets with high NFC/NDF (1.7) and UDP (50% of CP) improved metabolisable N supply to lambs.

  10. Effect of the Ratio of Non-fibrous Carbohydrates to Neutral Detergent Fiber and Protein Structure on Intake, Digestibility, Rumen Fermentation, and Nitrogen Metabolism in Lambs

    Directory of Open Access Journals (Sweden)

    T. Ma

    2015-10-01

    Full Text Available This study aimed to investigate the effect of the ratio of non-fibrous carbohydrates to neutral detergent fibre (NFC/NDF and undegraded dietary protein (UDP on rumen fermentation and nitrogen metabolism in lambs. Four Dorper×thin-tailed Han crossbred lambs, averaging 62.3±1.9 kg of body weight and 10 mo of age, were randomly assigned to four dietary treatments of combinations of two levels of NFC/NDF (1.0 and 1.7 and two levels of UDP (35% and 50% of crude protein [CP]. Duodenal nutrient flows were measured with dual markers of Yb and Co, and microbial N (MN synthesis was estimated using 15N. High UDP decreased organic matter (OM intake (p = 0.002 and CP intake (p = 0.005. Ruminal pH (p<0.001, ammonia nitrogen (NH3-N; p = 0.008, and total volatile fatty acids (p<0.001 were affected by dietary NFC/NDF. The ruminal concentration of NH3-N was also affected by UDP (p<0.001. The duodenal flow of total MN (p = 0.007 was greater for lambs fed the high NFC/NDF diet. The amount of metabolisable N increased with increasing dietary NFC:NDF (p = 0.02 or UDP (p = 0.04. In conclusion, the diets with high NFC/NDF (1.7 and UDP (50% of CP improved metabolisable N supply to lambs.

  11. Digestion and metabolism of carbohydrates in fish

    OpenAIRE

    Abro, Rani

    2014-01-01

    This thesis deals with the digestion and metabolism of carbohydrates in Arctic charr, Eurasian perch and tilapia. Two sources of carbohydrates, native starch (wheat) and chitin (zygomycete biomass), were evaluated. Gut tissue of Arctic charr displayed significant chitinase activity, of both endo- and exo-chitinase forms. Moreover, the distribution pattern along the gastrointestinal tract of Arctic charr differed between endo-chitinase and exo-chitinase. The endo-chitinase activity in sto...

  12. Effects of dietary fermented spent coffee ground on nutrient digestibility and nitrogen utilization in sheep.

    Science.gov (United States)

    Choi, Yongjun; Rim, Jong-Su; Na, Youngjun; Lee, Sang Rak

    2018-03-01

    The objective of the study was to determine the effect of fermented spent coffee ground (FSCG) on nutrient digestibility and nitrogen utilization in sheep. Fermentation of spent coffee ground (SCG) was conducted using Lactobacillus plantrum . Fermentation was performed at moisture content of 70% and temperature of 39°C with anaerobic air tension for 48 h. Four adult rams (initial body weight = 56.8±0.4 kg) were housed in a respiration-metabolism chamber and the treatments were: i) control (Basal diet; 0% SCG or FSCG), ii) 10% level of SCG, iii) 10% level of FSCG, and iv) 20% level of FSCG in 4×4 Latin square design. Each dietary experiment period lasted for 18-d with a 14-d of adaptation period and a 4-d of sample collection period. In SCG fermentation experimental result, acid detergent insoluble nitrogen (ADIN) concentration of FSCG (64.5% of total N) was lower than that of non-fermented SCG (78.8% of total N). Digestibility of dry matter and organic matter was similar among treatment groups. Although crude protein (CP) digestibility of the control was greater than FSCG groups (pdigestibility and nitrogen retention than non-fermented 10% SCG group (pdigestibility, thereby increasing CP digestibility and nitrogen utilization in sheep. Fermentation using microorganisms in feed ingredients with low digestibility could have a positive effect on improving the quality of raw feed.

  13. Nitrogen metabolism in the ruminant

    International Nuclear Information System (INIS)

    Buttery, P.J.; Lewis, D.

    1976-01-01

    Selected aspects of nitrogen metabolism in the ruminant are discussed. Particular attention is paid to the effect of rumen ammonia concentration on protein synthesis in the rumen. In order to judge the suitability of microbial protein as a source of protein for the ruminant, it is necessary to be able to assess the amino-acid requirements of the ruminant accurately. Several methods of doing this are discussed. Available data would indicate that under many conditions methionine is the first limiting amino acid. Possible ways of increasing the supply of methionine at the duodenum are discussed. When the amino-acid requirements are fully met, it is to be expected that protein synthesis in the tissues will proceed at its maximal rate. Ways of determining the extent of tissue protein synthesis in vivo are briefly discussed. (author)

  14. Voluntary intake, nitrogen metabolism and rumen fermentation ...

    African Journals Online (AJOL)

    Voluntary intake, nitrogen metabolism and rumen fermentation patterns in sheep given cowpea, silverleaf desmodium and fine-stem stylo legume hays as ... utilisation, the negative nitrogen retentions might indicate the inadequacy of the specific legume hays used as nitrogen supplementary feeds to sheep fed a basal diet

  15. Exchange of nitrogenous substances between the body pool and the digestive tract in ruminants

    International Nuclear Information System (INIS)

    Boda, K.; Varady, J.; Havassy, I.; Kosta, K.; Fejes, J.; Kowalczyk, J.

    1976-01-01

    For a period of three months the only source of nitrogen in a group of sheep fed on a synthetic protein-free diet was perorally administered urea, and for a further period of three months intravenously administered urea. It was found that there was practically no variation in the weight of the animals and in the nitrogen balance. The total content of nitrogen and amino-nitrogen in the rumen with intravenous nitrogenous feeding showed that the rumen is adequately supplied with endogenous nitrogen. A clear-cut increase - by a factor of 2 - was observed in the endogenous metabolism as a whole. In experiments on sheep with a fistula of the rumen, duodenum or ileum, it was found that nitrogenous matter (total and microbic), synthesized from the 15 N of intravenously administered urea, is transported by the digestive apparatus with the common nitrogenous substances. In the rumen-duodenum part these substances are mainly secreted and in the intestinal part reabsorbed. Of the 15 N that passed through the duodenum, 73-84% was reabsorbed. Of the administered material, 4.8-5.7% was eliminated in the faeces. In experiments on sheep with an isolated intestine, it was observed that the secretion of blood urea, mainly in the forward part of the jejunum, is relatively high (3.4-3.9mg/h, whereas the rate of NH 3 production due to hydrolysis is relatively low (0.28-0.35mg/h). Of the 15 N-urea introduced via the fistula into the forward part of the jejunum, the average amount of 15 N remaining in the organism is 63%. Equal amounts of 15 N were eliminated in the urine, altogether 37%. It is assumed that the exchange of nitrogen between the digestive apparatus and the body pool is an important link in the nitrogen metabolism of ruminants. The blood urea and synthesized nitrogenous substances are important sources of nitrogen for digestive processes and for protein synthesis. The entire digestive apparatus participates in the utilization of ureal nitrogen. (author)

  16. Comparative study on intake, digestibility and nitrogen balance of ...

    African Journals Online (AJOL)

    Four Red Sokoto bucks of average weight 15±2kg were fed different legumes hay in a mixed diet to evaluate their feed intake, digestibility and nitrogen balance. Using 4×4 Latin Square arrangement. The four test diets contained Maize offal, Rice husk, Salt, Bone meal and Cotton seed cake.while,20% of Soybean, ...

  17. Nitrogen utilisation and nitrient digestibility of west African dwarf ...

    African Journals Online (AJOL)

    An experiment to evaluate and compare the nitrogen utilization and nutrient digestibility of goat fed a pasture species (Cynodon nlemfuensis) or browse plant leaves (Spondias mombin or Gmelina arborea) based diets was conducted with fifteen (15) growing male West African Dwarf goats aged 7 – 7.5 months and ...

  18. Performance, Digestibility and Nitrogen Balance of West African ...

    African Journals Online (AJOL)

    The effect of dietary inclusions of ground tree leaves (Azadirachta indica, Newbouldia laevis and Spondias mombin) on performance, digestibility and nitrogen balance of West African dwarf goats was studied for a ten week period. Twenty four (24) bucks were (10.8±0.6 kg) distributed into four treatments (tree leaves and a ...

  19. Digestibility And Nitrogen Balance Studies In West African Dwarf ...

    African Journals Online (AJOL)

    Four West African Dwarf (WAD) rams averaging 10.5 kg of body weight and aged 16 months were used in a metabolism study to determine the intake and nutrient digestibility of potato chips fortified cassava peel poultry waste diets. Four experimental diets were formulated. They include diets A the control made up of 100% ...

  20. Nitrogen in the Process of Waste Activated Sludge Anaerobic Digestion

    Directory of Open Access Journals (Sweden)

    Suschka Jan

    2014-07-01

    Full Text Available Primary or secondary sewage sludge in medium and large WWTP are most often processed by anaerobic digestion, as a method of conditioning, sludge quantity minimization and biogas production. With the aim to achieve the best results of sludge processing several modifications of technologies were suggested, investigated and introduced in the full technical scale. Various sludge pretreatment technologies before anaerobic treatment have been widely investigated and partially introduced. Obviously, there are always some limitations and some negative side effects. Selected aspects have been presented and discussed. The problem of nitrogen has been highlighted on the basis of the carried out investigations. The single and two step - mesophilic and thermophilic - anaerobic waste activated sludge digestion processes, preceded by preliminary hydrolysis were investigated. The aim of lab-scale experiments was pre-treatment of the sludge by means of low intensive alkaline and hydrodynamic disintegration. Depending on the pretreatment technologies and the digestion temperature large ammonia concentrations, up to 1800 mg NH4/dm3 have been measured. Return of the sludge liquor to the main sewage treatment line means additional nitrogen removal costs. Possible solutions are discussed.

  1. Integration of metabolism and digestion in the hyrax | Fairall | South ...

    African Journals Online (AJOL)

    Metabolic adaptations and digestive ability were integrated to explain the ecological efficiency of the hyrax (Procavia capensis). Metabolic rate was shown to decrease linearly with a drop in ambient temperature, but at a lower rate than an animal of equivalent size, the guinea-pig (Cavia porcel/us). This is achieved by ...

  2. Digestible and indigestible carbohydrates: interactions with postprandial lipid metabolism.

    Science.gov (United States)

    Lairon, Denis; Play, Barbara; Jourdheuil-Rahmani, Dominique

    2007-04-01

    The balance between fats and carbohydrates in the human diet is still a matter of very active debate. Indeed, the processing of ordinary mixed meals involves complex processes within the lumen of the upper digestive tract for digestion, in the small intestine mucosa for absorption and resecretion, and in peripheral tissues and in the circulation for final handling. The purpose of this review is to focus on available knowledge on the interactions of digestible or indigestible carbohydrates with lipid and lipoprotein metabolism in the postprandial state. The observations made in humans after test meals are reported and interpreted in the light of recent findings on the cellular and molecular levels regarding possible interplays between carbohydrates and lipid moieties in some metabolic pathways. Digestible carbohydrates, especially readily digestible starches or fructose, have been shown to exacerbate and/or delay postprandial lipemia, whereas some fiber sources can lower it. While interactions between dietary fibers and the process of lipid digestion and absorption have been studied mainly in the last decades, recent studies have shown that dietary carbohydrate moieties (e.g., glucose) can stimulate the intestinal uptake of cholesterol and lipid resecretion. In addition to the well-known glucose/fructose transporters, a number of transport proteins have recently been involved in intestinal lipid processing, whose implications in such interactions are discussed. The potential importance of postprandial insulinemia in these processes is also evaluated in the light of recent findings. The interactions of carbohydrates and lipid moieties in the postprandial state may result from both acute and chronic effects, both at transcriptional and posttranscriptional levels.

  3. ASSOCIATIVE EFFECT OF MOLASSES-UREA BLOCK AND FORAGE QUALITY ON NUTRIENT DIGESTION AND NITROGEN RETENTION IN SHEEP

    Directory of Open Access Journals (Sweden)

    lqbal Saeed. M. M. Siddiqui and G. I. Habib

    2002-01-01

    Full Text Available A study was conducted in a 4x4 Latin square design involving four adult crossbred (Kaghani x Rambouillet weather kept in individual metabolic crates and four experimental diets viz: maize stovers (Diet A, maize stovers with 150 g/d molasses-urea block (Diet B, lucerne hay (Diet Cand lucerne hay with 150 g/d molasses-urea block (Diet D. The forage intake was restricted to 2% of body weight. Each experimental period consisted 10 days of adaptation followed by five days of data collection. Total dry matter intake on molasses-urea block (MUB supplemented diets was higher (p<0.05 than unsupplemented diets. The daily quantity of total dry matter and water consumed by weathers was higher (p < 0.001 on MUB supplemented diets. Water consumption was positively co-related to nitrogen intake (r2 0.66: p< 0.00 I and varied due to diets (p < 0.00 I. in vivo dry matter digestibility (DMD and organic matter digestibility (OMD of lucerne hay-based diets were greater (P< 005 than those containing maize stovers. Supplementation of MUB did not affect the DMD or OMD of the diets. The interaction of MUB and forage (P = 0.06 revealed that MUB was effective in increasing (P< 0.05 the nitrogen digestibility of maize stovers from 30,59% on diet A to 51.33% on diet B but did not affect the nitrogen digestibility in animals fed lucerne hay. The wethers receiving lucerne hay-based diets retained more nitrogen (p< 0.001 than those given maize stovers (8.50 's 3,12 g/d. Molasses-urea block supplementation on both forages increased (p < 0.05 the nitrogen retention. Mean nitrogen retention was I 82. 4.41, 7 .19 and 9.82 gld in wethers receiving diets A. B. C and D. respectively. Mean rumen ammonia concentration (mg N/lOO ml in wethers receiving maize stovers. was 10.52. which increased (p< 0,05 to 17.87 in response to MUB supplementation. On lucerne hay. the rumen ammonia concentrations did not change due to MUB and the mean values on diets C and D were 24,24 and 29.88 mg N/100

  4. Nitrogen Removal from Digested Black Water by One-stage Partial Nitritation and Anammox

    DEFF Research Database (Denmark)

    Vlaeminck, S.E.; Terada, Akihiko; Smets, Barth F.

    2009-01-01

    This study assessed the technical feasibility to treat digested black water from vacuum toilets (> 1000 mg NH4+-N L-1) in a lab-scale oxygen-limited autotrophic nitrification/denitrification (OLAND) rotating biological contactor. After an adaptation period of 2.5 months, a stable. nitrogen removal...... conversion was very low, in contrast to the high specific AnAOB activity. DGGE analysis showed that the dominant AerAOB and AnAOB species were resistant to the transition from synthetic medium to digested black water. This study demonstrates high-rate nitrogen removal from digested black water by one...

  5. Metabolic routes along digestive system of licorice: multicomponent sequential metabolism method in rat.

    Science.gov (United States)

    Zhang, Lei; Zhao, Haiyu; Liu, Yang; Dong, Honghuan; Lv, Beiran; Fang, Min; Zhao, Huihui

    2016-06-01

    This study was conducted to establish the multicomponent sequential metabolism (MSM) method based on comparative analysis along the digestive system following oral administration of licorice (Glycyrrhiza uralensis Fisch., leguminosae), a traditional Chinese medicine widely used for harmonizing other ingredients in a formulae. The licorice water extract (LWE) dissolved in Krebs-Ringer buffer solution (1 g/mL) was used to carry out the experiments and the comparative analysis was performed using HPLC and LC-MS/MS methods. In vitro incubation, in situ closed-loop and in vivo blood sampling were used to measure the LWE metabolic profile along the digestive system. The incubation experiment showed that the LWE was basically stable in digestive juice. A comparative analysis presented the metabolic profile of each prototype and its corresponding metabolites then. Liver was the major metabolic organ for LWE, and the metabolism by the intestinal flora and gut wall was also an important part of the process. The MSM method was practical and could be a potential method to describe the metabolic routes of multiple components before absorption into the systemic blood stream. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  6. Metatranscriptomic and metagenomic description of the bacterial nitrogen metabolism in waste water wet oxidation effluents

    Directory of Open Access Journals (Sweden)

    Julien Crovadore

    2017-10-01

    Full Text Available Anaerobic digestion is a common method for reducing the amount of sludge solids in used waters and enabling biogas production. The wet oxidation process (WOX improves anaerobic digestion by converting carbon into methane through oxidation of organic compounds. WOX produces effluents rich in ammonia, which must be removed to maintain the activity of methanogens. Ammonia removal from WOX could be biologically operated by aerobic granules. To this end, granulation experiments were conducted in 2 bioreactors containing an activated sludge (AS. For the first time, the dynamics of the microbial community structure and the expression levels of 7 enzymes of the nitrogen metabolism in such active microbial communities were followed in regard to time by metagenomics and metatranscriptomics. It was shown that bacterial communities adapt to the wet oxidation effluent by increasing the expression level of the nitrogen metabolism, suggesting that these biological activities could be a less costly alternative for the elimination of ammonia, resulting in a reduction of the use of chemicals and energy consumption in sewage plants. This study reached a strong sequencing depth (from 4.4 to 7.6 Gb and enlightened a yet unknown diversity of the microorganisms involved in the nitrogen pathway. Moreover, this approach revealed the abundance and expression levels of specialised enzymes involved in nitrification, denitrification, ammonification, dissimilatory nitrate reduction to ammonium (DNRA and nitrogen fixation processes in AS. Keywords: Applied sciences, Biological sciences, Environmental science, Genetics, Microbiology

  7. Effects of Dietary Nitrogen Level on Ruminal Fermentation, Digestibility and Metabolism of Nutrients in Yaks%饲粮氮水平对牦牛瘤胃发酵及营养物质消化代谢特征的影响

    Institute of Scientific and Technical Information of China (English)

    张莹; 郭旭生; 龙瑞军; 周建伟; 朱玉环; 米见对

    2011-01-01

    The experiment was conducted to investigate the effects of dietary nitrogen level on ruminal fermentation, digestibility and metabolism of nutrients in yaks. Four 3-year-old castrated yaks with a similar body weight of ( 148.5 ±9.2) kg were used in a 4 ×4 Latin square design. The experiment included four periods,and four different diets [crude protein (CP) levels on dry matter (DM) basis were 8.98%, 12.36%,15.32% and 18.12%, respectively]were fed to the animals for 21 days in each period. The results showed that changes of ruminal pH at different time were similar to a "V" shape after feeding in all of the four dietary groups. The lowest pH was observed in the 12.36% CP diet four hours after feeding (08:00 in the morning).With the increase of dietary nitrogen level, contents of acetate, propionate, isobutyrate, isovalerate and valerate were increased correspondingly ( P < 0.05), but no differences were observed in butyrate content and the ratio of acetate to propionate ( P > 0.05 ). Dietary nitrogen level did not affect the digestibility of DM, organic matter ( OM), nonfibrous carbohydrate ( NFC ), neutral detergent fiber (NDF) and acid detergent fiber (ADF) ( P < 0.05). Dietary nitrogen level had no influence on the amount of N excreted in the feces ( P >0.05 ). In contrast, the amount of N excreted in the urine was increased remarkably with the elevation of dietary nitrogen level (P <0.05). When the yaks were fed the 12.36% CP diet with the ratio of NFC to NDF at 0.38, the proportion of urinary nitrogen to digestible crude protein (DCP) was the lowest (52.88%), and the ratio of nitrogen retention to DCP was the highest (47.36%) among the four groups. Meanwhile, the highest microbial protein production was also obtained when yaks were fed the 12.36% CP diet. All these results suggest that the most efficiency in nitrogen utilization was obtained in yaks fed the 12.36% CP diet with the ratio of NFC to DCP at 1.36. [Chinese Journal of

  8. Metabolizable energy, nitrogen balance, and ileal digestibility of amino acids in quality protein maize for pigs

    Science.gov (United States)

    2014-01-01

    Background To compare the nutritional value and digestibility of five quality protein maize (QPM) hybrids to that of white and yellow maize, two experiments were carried out in growing pigs. In experiment 1, the energy metabolizability and the nitrogen balance of growing pigs fed one of five QPM hybrid diets were compared against those of pigs fed white or yellow maize. In experiment 2, the apparent and standardized ileal digestibility (AID and SID, respectively) of proteins and amino acids from the five QPM hybrids were compared against those obtained from pigs fed white and yellow maize. In both experiments, the comparisons were conducted using contrasts. Results The dry matter and nitrogen intakes were higher in the pigs fed the QPM hybrids (P digestibility (P digestible lysine than normal maize. PMID:25045520

  9. Rapid startup and high rate nitrogen removal from anaerobic sludge digester liquor using a SNAP process.

    Science.gov (United States)

    Qiao, Sen; Nishiyama, Takashi; Fujii, Tatsuo; Bhatti, Zafar; Furukawa, Kenji

    2012-02-01

    In this study, a single-stage autotrophic nitrogen removal reactor, packed with a novel acrylic fiber biomass carrier material (Biofix), was applied for nitrogen removal from sludge digester liquor. For rapid start-up, conventional activated sludge was added to the reactor soon after the attachment of anammox biomass on the Biofix carriers, which allowed conventional activated sludge to form a protective layer of biofilm around the anammox biomass. The Nitrogen removal efficiency reached 75% within 1 week at a nitrogen loading rate of 0.46 kg-N/m(3)/day for synthetic wastewater treatment. By the end of the synthetic wastewater treatment period, the maximum nitrogen removal rate had increased to 0.92 kg-N/m(3)/day at a nitrogen loading rate of 1.0 kg-N/m(3)/day. High nitrogen removal rate was also achieved during the actual raw digester liquor treatment with the highest nitrogen removal rate being 0.83 kg-N/m(3)/day at a nitrogen loading rate of 0.93 kg-N/m(3)/day. The thick biofilm on Biofix carriers allowed anammox bacteria to survive under high DO concentration of 5-6 mg/l resulting in stable and high nitrogen removal performance. FISH and CLSM analysis demonstrated that anammox bacteria coexisted and surrounded by ammonium oxidizing bacteria.

  10. Parameterization of a ruminant model of phosphorus digestion and metabolism.

    Science.gov (United States)

    Feng, X; Knowlton, K F; Hanigan, M D

    2015-10-01

    The objective of the current work was to parameterize the digestive elements of the model of Hill et al. (2008) using data collected from animals that were ruminally, duodenally, and ileally cannulated, thereby providing a better understanding of the digestion and metabolism of P fractions in growing and lactating cattle. The model of Hill et al. (2008) was fitted and evaluated for adequacy using the data from 6 animal studies. We hypothesized that sufficient data would be available to estimate P digestion and metabolism parameters and that these parameters would be sufficient to derive P bioavailabilities of a range of feed ingredients. Inputs to the model were dry matter intake; total feed P concentration (fPtFd); phytate (Pp), organic (Po), and inorganic (Pi) P as fractions of total P (fPpPt, fPoPt, fPiPt); microbial growth; amount of Pi and Pp infused into the omasum or ileum; milk yield; and BW. The available data were sufficient to derive all model parameters of interest. The final model predicted that given 75 g/d of total P input, the total-tract digestibility of P was 40.8%, Pp digestibility in the rumen was 92.4%, and in the total-tract was 94.7%. Blood P recycling to the rumen was a major source of Pi flow into the small intestine, and the primary route of excretion. A large proportion of Pi flowing to the small intestine was absorbed; however, additional Pi was absorbed from the large intestine (3.15%). Absorption of Pi from the small intestine was regulated, and given the large flux of salivary P recycling, the effective fractional small intestine absorption of available P derived from the diet was 41.6% at requirements. Milk synthesis used 16% of total absorbed P, and less than 1% was excreted in urine. The resulting model could be used to derive P bioavailabilities of commonly used feedstuffs in cattle production. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  11. Nitrogen removal from digested slurries using a simplified ammonia stripping technique.

    Science.gov (United States)

    Provolo, Giorgio; Perazzolo, Francesca; Mattachini, Gabriele; Finzi, Alberto; Naldi, Ezio; Riva, Elisabetta

    2017-11-01

    This study assessed a novel technique for removing nitrogen from digested organic waste based on a slow release of ammonia that was promoted by continuous mixing of the digestate and delivering a continuous air stream across the surface of the liquid. Three 10-day experiments were conducted using two 50-L reactors. In the first two, nitrogen removal efficiencies were evaluated from identical digestates maintained at different temperatures (30°C and 40°C). At the start of the first experiment, the digestates were adjusted to pH 9 using sodium hydroxide, while in the second experiment pH was not adjusted. The highest ammonia removal efficiency (87%) was obtained at 40°C with pH adjustment. However at 40°C without pH adjustment, removal efficiencies of 69% for ammonia and 47% for total nitrogen were obtained. In the third experiment two different digestates were tested at 50°C without pH adjustment. Although the initial chemical characteristics of the digestates were different in this experiment, the ammonia removal efficiencies were very similar (approximately 85%). Despite ammonia removal, the pH increased in all experiments, most likely due to carbon dioxide stripping that was promoted by temperature and mixing. The technique proved to be suitable for removing nitrogen following anaerobic digestion of livestock manure because effective removal was obtained at natural pH (≈8) and 40°C, common operating conditions at typical biogas plants that process manure. Furthermore, the electrical energy requirement to operate the process is limited (estimated to be 3.8kWhm -3 digestate). Further improvements may increase the efficiency and reduce the processing time of this treatment technique. Even without these advances slow-rate air stripping of ammonia is a viable option for reducing the environmental impact associated with animal manure management. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Intake, digestibility, and nitrogen balance of rations containing different levels of murumuru meal in sheep diets

    Directory of Open Access Journals (Sweden)

    Bruno Peres de Menezes

    2016-02-01

    Full Text Available This study aimed to assess the potential use of increasing levels of murumuru cake Astrocaryum murumuru var. murumuru, M art. (MC in sheep diets as a replacement for Mombasa grass (Panicum maximum Jacq. Metabolic tests were performed with 20 castrated male sheep at Embrapa Amazônia Oriental, Belém, Pará, during 26 days. The experiment was arranged in a completely randomized design, with five diets and four replications. MC0: 100% grass; MC10: 10% MC and 90% grass; MC20: 20% MC and 80% grass; MC40: 40% MC and 60% grass; and MC60: 60% MC and 40% grass. The intake and the coefficient of apparent digestibility of dry matter (DMI and CDDM, organic matter (OMI and CDOM, crude protein (CPI and CDCP, neutral detergent fiber (NDFI and CDNDF, acid detergent fiber (ADFI and CDADF, ether extract (EEI and CDEE, cellulose (CELI and CDCEL, hemicellulose (HEMI and CDHEM, and nitrogen balance (NB of experimental diets were determined. The intake of mineral material (MMI and lignin (LIGI were also determined. The DMI, OMI, MMI, CPI, NDFI, and ADFI displayed a decreasing linear effect with the replacement of Mombasa grass by MC in the diet. The EEI and the LIGI presented quadratic effects according to the replacement levels of MC in the diet. The CDDM, CDOM, and CDHEM displayed increasing linear effects, between MC0 and MC60. The CDEE, CDNDF, CDADF, and CDCEL displayed a quadratic effect, with optimum replacement levels of 56.65%, 41%, 31.33%, and 27.46%, respectively. The nitrogen balance presented a negative linear effect in the range of 0% to 60% of murumuru cake. One can conclude that murumuru cake is an alternative to the dietary supplementation of ruminants in replacing the Mombasa grass because it provides an increase in the digestibility of nutrients for sheep. However, a limited replacement level must be implemented, considering that from 27.46%, 31.33%, 41%, and 56.65% replacement, a decline occurs in the CDCEL, CDADF, CDNDF, and CDEE, respectively

  13. Exogenous trehalose improves growth under limiting nitrogen through upregulation of nitrogen metabolism.

    Science.gov (United States)

    Lin, Yingchao; Zhang, Jie; Gao, Weichang; Chen, Yi; Li, Hongxun; Lawlor, David W; Paul, Matthew J; Pan, Wenjie

    2017-12-19

    The trehalose (Tre) pathway has strong effects on growth and development in plants through regulation of carbon metabolism. Altering either Tre or trehalose 6-phosphate (T6P) can improve growth and productivity of plants as observed under different water availability. As yet, there are no reports of the effects of modification of Tre orT6P on plant performance under limiting nutrition. Here we report that nitrogen (N) metabolism is positively affected by exogenous application of Tre in nitrogen-deficient growing conditions. Spraying foliage of tobacco (Nicotiana tabacum) with trehalose partially alleviated symptoms of nitrogen deficiency through upregulation of nitrate and ammonia assimilation and increasing activities of nitrate reductase (NR), glycolate oxidase (GO), glutamine synthetase (GS) and glutamine oxoglutarate aminotransferase (GOGAT) with concomitant changes in ammonium (NH 4 + ) and nitrate (NO 3 - ) concentrations, glutamine and amino acids. Chlorophyll and total nitrogen content of leaves and rates of photosynthesis were increased compared to nitrogen-deficient plants without applied Tre. Total plant biomass accumulation was also higher in Tre -fed nitrogen-deficient plants, with a smaller proportion of dry weight partitioned to roots, compared to nitrogen-deficient plants without applied Tre. Consistent with higher nitrogen assimilation and growth, Tre application reduced foliar starch. Minimal effects of Tre feeding were observed on nitrogen-sufficient plants. The data show, for the first time, significant stimulatory effects of exogenous Tre on nitrogen metabolism and growth in plants growing under deficient nitrogen. Under such adverse conditions metabolism is regulated for survival rather than productivity. Application of Tre can alter this regulation towards maintenance of productive functions under low nitrogen. This has implications for considering approaches to modifying the Tre pathway for to improve crop nitrogen-use efficiency and

  14. Studies on growth, nitrogen and energy metabolism in rats

    DEFF Research Database (Denmark)

    Thorbek, G; Chwalibog, André; Eggum, B O

    1982-01-01

    Feed intake, growth, nitrogen retention and energy metabolism were measured in 12 male Wistar rats fed ad lib. for 14 weeks with non-purified diets. The feed intake increased rapidly in 4 weeks time from 16 g/d to 25 g/d, and then it was constant in the following 10 weeks. In relation to metabolic...

  15. Digestibility and nitrogen balance of diets containing non conventional vegetable proteins fed to pigs of genetic strains suitable for outdoor systems

    OpenAIRE

    L. Sardi; M. Simioli; R. Paganelli; G. Martelli; L. Rizzi

    2010-01-01

    The study was carried out to evaluate on growing pigs kept in metabolism crates, either belonging to a “traditional” cross-breed (Duroc x Large White – DLW) or a local breed (Cinta Senese – CS), the digestibility and the nitrogen balance of non-conventional vegetable protein sources (field beans, pea and sunflower cake) when compared to soybean meal. The four diets were formulated so as to supply the same crude protein amount. CS pigs showed lower apparent digestibilit...

  16. Drying characteristics and nitrogen loss of biogas digestate during drying process

    Energy Technology Data Exchange (ETDEWEB)

    Maurer, C.; Muller, J. [Hohenheim Univ., Stuttgart (Germany). Inst. of Agricultural Engineering, Tropical and Subtropical Group

    2010-07-01

    The cost of transporting biogas digestate can be decreased by reducing its water content. However, the digestate emits volatile compounds during drying. This study investigated the drying behaviour and the change of digestate composition. Drying took place in a hybrid solar/waste-heat dryer that used solar energy as well as waste heat from a combined heat and power unit (CHP) and the exhaust air of a microturbine. The experiment involved the use of 60 t of liquid digestate. Climatic conditions were measured inside and outside the drying hall. Dry matter (DM) and organic dry matter (ODM) were also measured on a daily basis. In addition, the energy consumption of waste and solar heat were recorded and related to the quantity of dried feedstock. The total nitrogen, ammonium, phosphate, potassium oxide, magnesium oxide and calcium oxide in the digestate were subjected to chemical analysis before and after the drying process. Losses of nitrogen were calculated. Specific energy consumption depended on the climatic condition. Most of the energy consumption was covered by the waste heat of the CHP. A considerable amount of nitrogen was lost during the drying process.

  17. Digestibility and nitrogen balance of diets containing non conventional vegetable proteins fed to pigs of genetic strains suitable for outdoor systems

    Directory of Open Access Journals (Sweden)

    L. Sardi

    2010-04-01

    Full Text Available The study was carried out to evaluate on growing pigs kept in metabolism crates, either belonging to a “traditional” cross-breed (Duroc x Large White – DLW or a local breed (Cinta Senese – CS, the digestibility and the nitrogen balance of non-conventional vegetable protein sources (field beans, pea and sunflower cake when compared to soybean meal. The four diets were formulated so as to supply the same crude protein amount. CS pigs showed lower apparent digestibility coefficients (ADCs for crude protein (81,38% vs 82,65% and crude fibre (35,97% vs 40,65%. Nitrogen balance was more favourable in DLW pigs (32,12% vs 19,67% which showed a higher nitrogen retention (+69%.With respect to the protein source, no differences were observed for nitrogen balance. Sunflower diet showed the higher ADC for ether extract (+20% compared with soybean diet. Crude fibre digestibility was lowered in sunflower (-33% and field beans (-13% diets. Sunflower and field beans diets showed the lowest gross energy digestibility coefficients. Field pea diet had the highest ADC for crude fibre (+ 12% leading to ADCs for organic matter and gross energy comparable to those of soybean meal. It is concluded that field bean, sunflower cake and field pea could be considered as valuable non-conventional protein sources in swine nutrition.

  18. Consumo, digestibilidade e excreção de uréia e derivados de purinas em vacas de diferentes níveis de produção de leite Intake, digestibility and nitrogen metabolism in Holstein cows with different milk production levels

    Directory of Open Access Journals (Sweden)

    Mário Luiz Chizzotti

    2007-02-01

    Full Text Available Objetivou-se avaliar o efeito do nível de produção de leite sobre o consumo e a digestibilidade dos nutrientes (MS, MO, EE, PB, FDNcp e CNF corrigidos, o consumo de NDT, a produção de proteína microbiana e a excreção de compostos nitrogenados na urina. Foram avaliadas as concentrações de N uréico no soro (NUS e no leite (NUL de animais de diferentes níveis de produção de leite. Foram comparadas as metodologias de coletas de urina spot e total para quantificação do fluxo de N microbiano. Quinze vacas holandesas foram alocadas em delineamento inteiramente casualizado, com três tratamentos, de acordo com a produção de leite: 5,88 (baixa; 18,54 (média e 32,6 kg de leite/dia (alta. A dieta foi constituída de silagem de milho fornecida à vontade e 1 kg de concentrado para cada 3 kg de leite produzido. Os consumos de todos os nutrientes, exceto FDNcp, foram maiores nos animais mais produtivos. As digestibilidades de MS e MO e o teor de NDT não diferiram entre os tratamentos, mas as digestibilidades da PB e da FDNcp foram influenciadas pelo nível de produção, sendo maior e menor, respectivamente, nos animais de alta produção. Os teores de NUS e NUL e a excreção de compostos nitrogenados na urina foram altamente correlacionados e superiores nos animais mais produtivos, indicando que a concentração ótima varia com o nível de produção de leite. A produção microbiana não diferiu entre as metodologias de coleta spot e total de urina, sendo inferior nos animais menos produtivos. Assim, a coleta de urina spot pode ser utilizada para estimar a excreção de compostos nitrogenados na urina e a produção de proteína microbiana no rúmen.The objective of this trial was to evaluate the effect of milk production level on intake, digestibility of nutrients, microbial protein synthesis, and nitrogen (N metabolism in Holstein cows. It was also of particular interest to compare spot urine sampling and total urine collection as

  19. Characterizing the transformation and transfer of nitrogen during the aerobic treatment of organic wastes and digestates

    Energy Technology Data Exchange (ETDEWEB)

    Zeng Yang, E-mail: yang.zeng@irstea.fr [Irstea, UR GERE, 17 avenue de Cucille, CS 64427, F-35044 Rennes Cedex (France); Universite Europeenne de Bretagne, F-35000 Rennes (France); Guardia, Amaury de; Daumoin, Mylene; Benoist, Jean-Claude [Irstea, UR GERE, 17 avenue de Cucille, CS 64427, F-35044 Rennes Cedex (France)

    2012-12-15

    Highlights: Black-Right-Pointing-Pointer Ammonia emissions varied depending on the nature of wastes and the treatment conditions. Black-Right-Pointing-Pointer Nitrogen losses resulted from ammonia emissions and nitrification-denitrification. Black-Right-Pointing-Pointer Ammonification can be estimated from biodegradable carbon and carbon/nitrogen ratio. Black-Right-Pointing-Pointer Ammonification was the main process contributing to N losses. Black-Right-Pointing-Pointer Nitrification rate was negatively correlated to stripping rate of ammonia nitrogen. - Abstract: The transformation and transfer of nitrogen during the aerobic treatment of seven wastes were studied in ventilated air-tight 10-L reactors at 35 Degree-Sign C. Studied wastes included distinct types of organic wastes and their digestates. Ammonia emissions varied depending on the kind of waste and treatment conditions. These emissions accounted for 2-43% of the initial nitrogen. Total nitrogen losses, which resulted mainly from ammonia emissions and nitrification-denitrification, accounted for 1-76% of the initial nitrogen. Ammonification was the main process responsible for nitrogen losses. An equation which allows estimating the ammonification flow of each type of waste according to its biodegradable carbon and carbon/nitrogen ratio was proposed. As a consequence of the lower contribution of storage and leachate rates, stripping and nitrification rates of ammonia nitrogen were negatively correlated. This observation suggests the possibility of promotingnitrification in order to reduce ammonia emissions.

  20. Removal of nitrogen from anaerobically digested swine wastewater ...

    African Journals Online (AJOL)

    This result indicates that the sulfur-packed biofilter would be used as an efficient option for denitrification by autotrophic denitrifiers during swine wastewater treatment. Key words: Biological nitrogen removal, nitrification, denitrification, chemical oxygen demand (COD), intermittent aeration, sulfur-packed bed reactor, swine ...

  1. Potential for chlorate interference in ion chromatographic determination of total nitrogen in natural waters following alkaline persulfate digestion.

    Science.gov (United States)

    Halstead, J A; Edwards, J; Soracco, R J; Armstrong, R W

    1999-10-01

    Determination of total nitrogen in aqueous samples after thermal potassium peroxydisulfate (persulfate) digestion is a commonly used alternative to the tedious Kjeldahl procedure. When ion chromatography is used to quantify the nitrate formed during digestion, there is a potential for interference from a chlorate peak if the digested sample initially contained chloride in concentrations close to or greater than the concentration of nitrogen. It was determined that this interference can be avoided either by using chromatographic conditions which cleanly resolve the nitrate and chlorate peaks (e.g., the Dionex AG9-HG column) or by using digestion reagent concentrations chosen to maintain a high pH throughout the digestion. The second alternative is not a viable option for investigators using a single digestion for both total nitrogen (TN) and total phosphorus (TP) analysis.

  2. Anaerobic co-digestion of perennials: Methane potential and digestate nitrogen fertilizer value

    DEFF Research Database (Denmark)

    Muller-Stover, Dorette Sophie; Sun, Guotao; Kroff, Pablo

    2016-01-01

    Co-digestion of crop biomass improves the traditional manure-based biogas yield due to an increased content of easily degradable carbon compounds. In this study, the methane potential of three perennials (grass, legumes, and grass+legume) was determined using various amounts together with animal ...

  3. Understanding Plant Nitrogen Metabolism through Metabolomics and Computational Approaches

    Directory of Open Access Journals (Sweden)

    Perrin H. Beatty

    2016-10-01

    Full Text Available A comprehensive understanding of plant metabolism could provide a direct mechanism for improving nitrogen use efficiency (NUE in crops. One of the major barriers to achieving this outcome is our poor understanding of the complex metabolic networks, physiological factors, and signaling mechanisms that affect NUE in agricultural settings. However, an exciting collection of computational and experimental approaches has begun to elucidate whole-plant nitrogen usage and provides an avenue for connecting nitrogen-related phenotypes to genes. Herein, we describe how metabolomics, computational models of metabolism, and flux balance analysis have been harnessed to advance our understanding of plant nitrogen metabolism. We introduce a model describing the complex flow of nitrogen through crops in a real-world agricultural setting and describe how experimental metabolomics data, such as isotope labeling rates and analyses of nutrient uptake, can be used to refine these models. In summary, the metabolomics/computational approach offers an exciting mechanism for understanding NUE that may ultimately lead to more effective crop management and engineered plants with higher yields.

  4. Emiliania Huxleyi (Prymnesiophyceae): Nitrogen-metabolism genes and their expression in response to external nitrogen souces

    DEFF Research Database (Denmark)

    Bruhn, Annette; LaRoche, Julie; Richardson, Katherine

    2010-01-01

    The availability and composition of dissolved nitrogen in ocean waters are factors that influence species composition in natural phytoplankton communities. The same factors affect the ratio of organic to inorganic carbon incorporation in calcifying species, such as the coccolithophore Emiliania...... huxleyi (Lohman) W. W. Hay et H. Mohler. E. huxleyi has been shown to thrive on various nitrogen sources, including dissolved organic nitrogen. Nevertheless, assimilation of dissolved nitrogen under nitrogen-replete and -limited conditions is not well understood in this ecologically important species....... In this study, the complete amino acid sequences for three functional genes involved in nitrogen metabolism in E. huxleyi were identified: a putative formamidase, a glutamine synthetase (GSII family), and assimilatory nitrate reductase. Expression patterns of the three enzymes in cells grown on inorganic...

  5. Digestate application in landfill bioreactors to remove nitrogen of old landfill leachate.

    Science.gov (United States)

    Peng, Wei; Pivato, Alberto; Lavagnolo, Maria Cristina; Raga, Roberto

    2018-04-01

    Anaerobic digestion of organics is one of the most used solution to gain renewable energy from waste and the final product, the digestate, still rich in putrescible components and nutrients, is mainly considered for reutilization (in land use) as a bio-fertilizer or a compost after its treatment. Alternative approaches are recommended in situations where conventional digestate management practices are not suitable. Aim of this study was to develop an alternative option to use digestate to enhance nitrified leachate treatment through a digestate layer in a landfill bioreactor. Two identical landfill columns (Ra and Rb) filled with the same solid digestate were set and nitrified leachate was used as influent. Ra ceased after 75 day's operation to get solid samples and calculate the C/N mass balance while Rb was operated for 132 days. Every two or three days, effluent from the columns were discarded and the columns were refilled with nitrified leachate (average N-NO 3 - concentration = 1,438 mg-N/L). N-NO 3 - removal efficiency of 94.7% and N-NO 3 - removal capacity of 19.2 mg N-NO 3 - /gTS-digestate were achieved after 75 days operation in Ra. Prolonging the operation to 132 days in Rb, N-NO 3 - removal efficiency and N-NO 3 - removal capacity were 72.5% and 33.1 mg N-NO 3 - /gTS-digestate, respectively. The experimental analysis of the process suggested that 85.4% of nitrate removal could be attributed to denitrification while the contribution percentage of adsorption was 14.6%. These results suggest that those solid digestates not for agricultural or land use, could be used in landfill bioreactors to remove the nitrogen from old landfill leachate. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Determination of nitrogen absorption and endogenous nitrogen secretion in the digestive tract of pigs fed with nitrogen-15-labelled dried whey

    International Nuclear Information System (INIS)

    Gebhardt, G.; Souffrant, W.; Koehler, R.; Zebrowska, T.

    1977-01-01

    Two fistulated pigs weighing between 15kg and 54kg were given experimental diets containing 15 N-labelled dried whey. The labelled experimental diets were given once only. Samples of the digesta were taken from the duodenum and terminal ileum at various intervals of time up to 48h after feeding the labelled protein feed. The digesta were separated into the four following fractions: Residue on centrifugation, proteins, peptides and free amino acids. The secretion of endogenous nitrogen in the duodenum was 12.5g/24h in pigs having a live weight of 50kg. The endogenous nitrogen was found to be relatively uniformly distributed among the four fractions. The rate of secretion of endogenous nitrogen showed a continuous decrease during 24h. The secretion of endogenous nitrogen in the terminal ileum was 54 to 60mg of nitrogen per kilogram live weight. After passage through the small intestine the greater part of the free amino acids in digesta was of exogenous origin. In the protein fraction most came from endogenous proteins. A true absorption of 17% of nitrogen was determined in the duodenum. The amount of nitrogen absorbed in the terminal part of the small intestine was, on average, 90% relative to the nitrogen intake. The true digestibility calculated with the amount of 15 N in food and faeces was 98%. (author)

  7. Characterisation of a major enzyme of bovine nitrogen metabolism

    CSIR Research Space (South Africa)

    Mathomu, LM

    2010-09-01

    Full Text Available of cellular protein metabolism (Curthoys & Watford, 1995; Meister, 1974). Glutamine functions as a major inter-organ transport form of nitrogen, carbon and serves as a source of energy between tissues such as brain, liver, kidney and even muscles...

  8. Nitrogen, carbon, and sulfur metabolism in natural Thioploca samples

    DEFF Research Database (Denmark)

    Otte, S.; Kuenen, JG; Nielsen, LP

    1999-01-01

    Filamentous sulfur bacteria of the genus Thioploca occur as dense mats on the continental shelf off the coast of Chile and Peru. Since little is known about their nitrogen, sulfur, and carbon metabolism, this study was undertaken to investigate their (eco)physiology. Thioploca is able to store...

  9. Nitrogen metabolism and microbial production of dairy cows fed sugarcane and nitrogen compounds

    OpenAIRE

    Gonçalves,Geógenes da Silva; Pedreira,Marcio dos Santos; Pereira,Mara Lúcia Albuquerque; Santos,Dimas Oliveira; Souza,Dicastro Dias de; Porto Junior,Antonio Ferraz

    2014-01-01

    The aim of this study was to evaluate the effect of dairy cow diets containing two different sources of urea on nitrogen metabolism and microbial synthesis. Eight crossbred cows were confined and distributed in two 4x4 Latin: FS - soybean meal (control), conventional urea (UC) 100%; ULL 44 UC = 56% / 44% ULL, ULL 88 UC = 12% / 88% ULL. Diets were offered to animals during 21 days with 14 days of adaptation. The N intake, retained nitrogen balance, nitrogen excretion in milk, urine, feces and ...

  10. Influence of different fibre sources on digestibility and nitrogen and energy balances in growing pigs

    DEFF Research Database (Denmark)

    Hansen, Michael Jørgen; Chwalibog, André; Tauson, Anne-Helene

    2006-01-01

    The present study was undertaken to investigate how three different fibre sources, sugar beet pulp, soya bean hulls and pectin residue, constituting 15% of diets for growing pigs, influenced daily body gain, feed conversion, apparent faecal digestibility and nitrogen and energy balances. Eight......) and energy were significantly lower for the fibre diets (OM: 0.81-0.85; energy: 0.78-0.83) compared to the control diet (OM: 0.88; energy: 0.86). The apparent faecal digestibility of crude protein (CP) was lower for the fibre diets (0.71-0.78) compared to the control diet (0.83), although it was only...... significantly lower for the sugar beet pulp and pectin residue diets. The pectin residue diet, which contained the highest amount of dietary fibre, lignin and insoluble non-starch polysaccharides, had the lowest digestibility of OM, CP and energy. There was a tendency (p = 0.07) for a diet effect on retained...

  11. The effect of zilpaterol hydrochloride supplementation on energy metabolism and nitrogen and carbon retention of steers fed at maintenance and fasting intake levels

    Science.gov (United States)

    An indirect calorimetry trial examined energy metabolism, apparent nutrient digestibility (appND), carbon retention (CR) and nitrogen retention (NR) of cattle supplemented with zilpaterol hydrochloride (Z). Beef steers (n=20; 463 ± 14 kg) blocked (n=5) by weight and source were individually fed and ...

  12. Effect of feeding a by-product feed-based silage on nutrients intake, apparent digestibility, and nitrogen balance in sheep.

    Science.gov (United States)

    Seok, J S; Kim, Y I; Lee, Y H; Choi, D Y; Kwak, W S

    2016-01-01

    Literature is lacking on the effects of feeding by-product feed (BF)-based silage on rumen fermentation parameters, nutrient digestion and nitrogen (N) retention in sheep. Therefore, this study was conducted to determine the effect of replacing rye straw with BF-based silage as a roughage source on ruminal parameters, total-tract apparent nutrient digestibility, and N balance in sheep. The by-product feed silage was composed of spent mushroom substrate (SMS) (45 %), recycled poultry bedding (RPB) (21 %), rye straw (11 %), rice bran (10.8 %), corn taffy residue (10 %), protected fat (1.0 %), bentonite (0.6 %), and mixed microbial additive (0.6 %). Six sheep were assigned randomly to either the control (concentrate mix + rye straw) or a treatment diet (concentrate mix + BF-based silage). Compared with the control diet, feeding a BF-based silage diet resulted in similar ruminal characteristics (pH, acetate, propionate, and butyrate concentrations, and acetate: propionate ratio), higher (p < 0.05) ruminal NH3-N, higher (p < 0.05) ether extract digestibility, similar crude protein digestibility, lower (p < 0.05) dry matter, fiber, and crude ash digestibilities, and higher (p < 0.05) N retention (g/d). The BF-based silage showed similar energy value, higher protein metabolism and utilization, and lower fiber digestion in sheep compared to the control diet containing rye straw.

  13. Mesquite pod meal in sheep diet: intake, apparent digestibility of nutrients and nitrogen balance

    Directory of Open Access Journals (Sweden)

    Edileusa de Jesus do Santos

    2015-02-01

    Full Text Available Eight Santa Ines sheep were assigned to two 4 x 4 Latin squares, to evaluate the effects of replacing elephant grass silage with different levels of mesquite pod meal (MDM (15, 30 and 45% DM on intake, apparent digestibility of dry matter (DM, organic matter (OM, crude protein (CP, ether extract (EE, acid detergent fiber (ADF, neutral detergent fiber (NDF, total carbohydrates (TC and non-fiber carbohydrates (NFC and the nitrogen balance. There was a linear increase (p < 0.05 in the intake of DM, OM, CP, ADF, NDF, NFC and TC according to the addition of MPM to the diet. The digestibility of DM, OM and CP increased (p < 0.05 with the addition of MDM. We observed a positive linear effect (p < 0.05 for the nitrogen intake. The addition of mesquite pod meal up to 45% increased the intake of DM, NDF, ADF, CP, OM, NFC and TC but reduced the digestibility of EE and NDF. MPM at 30 and 45% propitiated a positive nitrogen balance.

  14. Effect of nitrogen fertilisation on the amino acid digestibility of different triticale genotypes in caecectomised laying hens.

    Science.gov (United States)

    Siegert, Wolfgang; Boguhn, Jeannette; Maurer, Hans Peter; Weiss, Jochen; Zuber, Tobias; Möhring, Jens; Rodehutscord, Markus

    2017-01-01

    The influence of nitrogen fertilisation and genotype on the amino acid (AA) digestibility of triticale grain was investigated in caecectomised laying hens. Three genotypes, Grenado, EAW6002 and Lasko, were cultivated with and without nitrogen fertilisation at the end of the heading stage. The six triticale variants as well as a basal diet were each used to feed seven laying hens in a 7 × 7 Latin square design. Nitrogen fertilisation influenced the digestibility of Cys, Glu, Phe and Ser in some triticale genotypes and reduced Ala, Ile, Lys, Met and Val digestibility in all genotypes (P digestible AAs in the grains was increased for most AAs upon nitrogen fertilisation. Overall, Lys had the lowest digestibility, whereas that of Glu and Pro was the highest. For the triticale genotypes, the level of AA digestibility was highest for EAW6002 followed by Lasko and Grenado, with significant differences (P digestible AA supply for hen feeding might benefit from considering fertilisation and genotype-specific digestibility data in feed formulation. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  15. Effects of solid-liquid separation on recovering residual methane and nitrogen from digested dairy cow manure

    DEFF Research Database (Denmark)

    Kaparaju, Prasad Laxmi-Narasimha; Rintala, J.A.

    2008-01-01

    The feasibility of optimizing methane and nitrogen recovery of samples obtained from farm biogas digester (35 degrees C) and post-storage tank (where digested material is stored for 9-12 months) was studied by separating the materials into different fractions using 2, 1, 0.5 and 0.25 mm sieves...

  16. Patterns of nutrient utilization. Implications for nitrogen metabolism

    International Nuclear Information System (INIS)

    Oldham, J.D.

    1983-01-01

    Nutrients react within both the rumen and the ruminant body, and the patterns of availability of different nutrients greatly influence their net utilization. In the rumen, microbial capture of N substrates, especially ammonia, depends on the degree of synchronization between rates of production of N substrates and of ATP to drive microbial protein synthesis. The form of dietary carbohydrate and of dietary N and the frequency of feeding can all affect the efficiency of microbial growth and digestion. The pattern of supply of nutrients to the body will also influence nutrient utilization. Disparities between diurnal patterns of supply of volatile fatty acids from the rumen and amino acids from the intestines will result in changes in balance of metabolic pathways. The balance between supply of glucogenic and lipogenic nutrients will influence efficiency of fattening. A major factor determining the pattern of utilization/metabolism of amino acids is the metabolic demand for protein synthesis, which varies with physiological state. (author)

  17. Bakery waste in sheep diets: intake, digestibility, nitrogen balance and ruminal parameters

    Directory of Open Access Journals (Sweden)

    Almira Biazon França

    2012-01-01

    Full Text Available The objective of the study was to evaluate the effects of bakery waste inclusion (0; 25; 50; 75 and 100%, DM basis in proportion to corn meal in the energetic mixture of the concentrate on intake, digestibility, nitrogen balance and ruminal parameters in sheep. Five male lambs with body weight of 30 kg were used in a 5 × 5 Latin square design. Experimental diets were composed of concentrate and Tifton 85 (Cynodon spp. hay in a 60:40 forage:concentrate ratio. The concentrate rations were composed of corn meal, soybean meal and bakery waste. The bakery waste:corn meal ratio corresponded to the inclusion of, approximately, 0, 7, 14, 22 and 30% (DM basis of bakery waste in the diet. There was no effect of bakery waste inclusion on the intake and digestibility of nutrients, nor on nitrogen balance, pH values or concentrations of volatile fatty acids. However, the ammonia nitrogen concentration showed negative linear response in relation to the level of inclusion, in which each increase of 1% bakery waste promoted reduction of 0.11 mg/dL in the concentration of ammonia nitrogen. This fact may be related to the increase in ruminal availability of energy, which allows greater use of ammonia for microbial growth. Bakery waste can replace corn meal in concentrate rations for sheep.

  18. - Invited Review - Calcium Digestibility and Metabolism in Pigs*

    Science.gov (United States)

    González-Vega, J. C.; Stein, H. H.

    2014-01-01

    Calcium (Ca) and phosphorus (P) are minerals that have important physiological functions in the body. For formulation of diets for pigs, it is necessary to consider an appropriate Ca:P ratio for an adequate absorption and utilization of both minerals. Although both minerals are important, much more research has been conducted on P digestibility than on Ca digestibility. Therefore, this review focuses on aspects that are important for the digestibility of Ca. Only values for apparent total tract digestibility (ATTD) of Ca have been reported in pigs, whereas values for both ATTD and standardized total tract digestibility (STTD) of P in feed ingredients have been reported. To be able to determine STTD values for Ca it is necessary to determine basal endogenous losses of Ca. Although most Ca is absorbed in the small intestine, there are indications that Ca may also be absorbed in the colon under some circumstances, but more research to verify the extent of Ca absorption in different parts of the intestinal tract is needed. Most P in plant ingredients is usually bound to phytate. Therefore, plant ingredients have low digestibility of P due to a lack of phytase secretion by pigs. During the last 2 decades, inclusion of microbial phytase in swine diets has improved P digestibility. However, it has been reported that a high inclusion of Ca reduces the efficacy of microbial phytase. It is possible that formation of insoluble calcium-phytate complexes, or Ca-P complexes, not only may affect the efficacy of phytase, but also the digestibility of P and Ca. Therefore, Ca, P, phytate, and phytase interactions are aspects that need to be considered in Ca digestibility studies. PMID:25049919

  19. Struvite Crystallization of Anaerobic Digestive Fluid of Swine Manure Containing Highly Concentrated Nitrogen

    Directory of Open Access Journals (Sweden)

    Eun Young Lee

    2015-07-01

    Full Text Available In this study, the optimal operation factors for struvite crystallization for removing and recovering nitrogen and phosphorus from anaerobic digestive fluid of swine manure containing highly concentrated nitrogen was determined. Every experiment for the struvite crystallization reaction was conducted by placing 1,000 mL of digestion fluid in a 2,000 mL Erlenmeyer flask at various temperatures, pH, and mixing speed. Except for special circumstances, the digestion fluid was centrifuged (10,000 rpm, 10 min and then the supernatant was used for the experiment at room temperature and 100 rpm. The optimal mole ratio of PO43−:Mg2+ was 1:1.5, and the pH effect ranging from 9 to 11 was similar, when mixed for 1 hour. Under this condition, the removal efficiency of NH4+-N and PO43−-P was 40% and 88.6%, respectively. X-shaped crystal was observed by light and scanning electron microscopy. In addition, struvite crystal structure was confirmed through X-ray diffraction analysis.

  20. Nitrogen metabolism in the tissues of the ruminant

    International Nuclear Information System (INIS)

    Buttery, P.J.

    1986-01-01

    Protein metabolism in animals is in a constant state of flux, the processes of protein synthesis and protein breakdown acting against each other, and the balance between the two processes causing changes in the mass of protein in a tissue. Reduction in the diet reduces both protein synthesis and protein degradation unless the dietary depletion is severe and prolonged, when there is a marked increase in protein catabolism. The synthesis and degradation of protein can be manipulated by anabolic agents, thus increasing the efficiency of animals. While the use of these agents has met with success in many countries, it remains to be seen whether they will be useful in harsh environments. Lactation and pregnancy put an extra demand on the nitrogen economy of animals. Evidence indicates that the extra amino acids needed for milk production do not come from muscle protein breakdown. Many animals in harsh environments are infected with parasites; intestinal parasites reduce food intake and cause blood loss into the intestines. Associated with this is a general disruption of protein metabolism. In all these studies, isotopic techniques have played a vital role. Few studies have been conducted on nitrogen metabolism in the tissue of ruminants exposed to harsh environments (with one notable exception: rumen function studies, some of which are described elsewhere in the Proceedings of this Seminar). This lack of work on nitrogen metabolism of animals from the harsher environments has often made it necessary to extrapolate data obtained from animals found and maintained in the temperate zones to quite different environments and to animals maintained on quite different dietary regimens. Several examples of the use of isotopes in metabolic studies with animals to yield information of direct or potential relevance to the harsh environments are presented. (author)

  1. Synthesis of microbial nitrogen compounds in the rumen and their digestion in the small intestine

    International Nuclear Information System (INIS)

    Smith, R.H.; Salter, D.N.; McAllan, A.B.; Williams, A.P.

    1976-01-01

    Pathways and efficiency of NPN utilization were studied after introducing isonitrogenous feeds containing urea labelled with 15 N with or without groundnut protein into the rumen of the young steer. The 15 N abundance in rumen ammonia decreased from 1 h after the dose whereas that in suspended bacteria (only a small part of the total population but regarded, with reservation, as representative) increased to a peak value at 3-5 h. Patterns of incorporation into different nitrogen constituents of the bacteria indicated that part of the 15 N first moved rapidly into a labile pool, which included amide nitrogen, and then moved from this pool into other amino acids. Different amino acids were labelled to different extents (lowest for proline and arginine, highest for aspartic acid and alanine), presumably as different amounts of pre-formed amino acids were used in protein synthesis. Differences largely disappeared when the diet with urea as the only nitrogen source was given. Estimates of microbial 15 N recovery at the duodenum confirmed earlier findings that overall incorporation was least when the latter diet was given, and no improvement was seen when the urea was given in three doses over 4 h instead of in a single dose. Lactosyl, like glucosyl, ureide was degraded fairly slowly in the rumen and is being studied as a possible NPN source likely to yield simultaneous ammonia and energy for microbial growth. Studies on the origin and composition of nitrogen compounds entering the duodenum showed that the RNA of rumen bacteria (labelled with 32 P) contributed 82-109% of the RNA entering the duodenum of the steer. It was also shown that protecting dietary casein with formaldehyde reduced its degradability in the rumen to such an extent that a deficiency of fermentable nitrogen in that organ ensued. In other experiments with two calves receiving flaked maize and hay, net digestibility of nitrogen compounds between duodenum and ileum was about 60%. True digestibility

  2. Nitrogen losses to the environment following food-based digestate and compost applications to agricultural land.

    Science.gov (United States)

    Nicholson, Fiona; Bhogal, Anne; Cardenas, Laura; Chadwick, Dave; Misselbrook, Tom; Rollett, Alison; Taylor, Matt; Thorman, Rachel; Williams, John

    2017-09-01

    The anaerobic digestion of food waste for energy recovery produces a nutrient-rich digestate which is a valuable source of crop available nitrogen (N). As with any 'new' material being recycled to agricultural land it is important to develop best management practices that maximise crop available N supply, whilst minimising emissions to the environment. In this study, ammonia (NH 3 ) and nitrous oxide (N 2 O) emissions to air and nitrate (NO 3 - ) leaching losses to water following digestate, compost and livestock manure applications to agricultural land were measured at 3 sites in England and Wales. Ammonia emissions were greater from applications of food-based digestate (c.40% of total N applied) than from livestock slurry (c.30% of total N applied) due to its higher ammonium-N content (mean 5.6 kg/t compared with 1-2 kg/t for slurry) and elevated pH (mean 8.3 compared with 7.7 for slurry). Whilst bandspreading was effective at reducing NH 3 emissions from slurry compared with surface broadcasting it was not found to be an effective mitigation option for food-based digestate in this study. The majority of the NH 3 losses occurred within 6 h of spreading highlighting the importance of rapid soil incorporation as a method for reducing NH 3 emissions. Nitrous oxide losses from food-based digestates were low, with emission factors all less than the IPCC default value of 1% (mean 0.45 ± 0.15%). Overwinter NO 3 - leaching losses from food-based digestate were similar to those from pig slurry, but much greater than from pig farmyard manure or compost. Both gaseous N losses and NO 3 - leaching from green and green/food composts were low, indicating that, in these terms, compost can be considered as an 'environmentally benign' material. These findings have been used in the development of best practice guidelines which provide a framework for the responsible use of digestates and composts in agriculture. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Effect of N,N-dimethylglycine supplementation in parturition feed for sows on metabolism, nutrient digestibility and reproductive performance.

    Science.gov (United States)

    Cools, A; Maes, D; Buyse, J; Kalmar, I D; Vandermeiren, J-A; Janssens, G P J

    2010-12-01

    The current pilot study assessed the influence of N,N-dimethylglycine (DMG) on insulin sensitivity, glucose and fat metabolism, nutrient digestibility and reproductive performance of sows in the peripartal period. At day 105 of gestation, 25 sows were randomly assigned to the control (n = 13) or the DMG group (n = 12). Sows from the DMG group were supplemented with 1 g DMG/kg feed until day 3 of lactation. After an overnight fast 1 day after farrowing, a blood sample of each sow was drawn. The plasma was analyzed for insulin, glucose, fructosamine, leptin, thiobarbituric acid reactive substances (TBARS), ferric reducing ability of plasma (FRAP), non-esterified fatty acids (NEFA) and triglycerides (TG) and an oral glucose tolerance test was performed. A rectal feces sample was collected and the apparent fecal digestibility (AFD) of crude fat (CFAT), crude protein (CP) and nitrogen-free extract (NFE) was calculated after proximate analyses. Finally, a colostrum sample was collected from each sow and analyzed for the presence of DMG. Reproductive performance parameters were recorded. The results showed an improvement in the AFD of CFAT, CP and NFE when DMG was supplemented. This beneficial effect confirms the hypothesis that DMG acts as an emulsifying agent. The improvement in digestibility in the DMG group was accompanied by a numerical increase in plasma TG (P = 0.067). Plasma NEFA concentrations were not different between treatment groups. DMG supplementation neither affected glucose clearance nor influenced plasma insulin, glucose, fructosamine or leptin levels. TBARS and FRAP also remained unaffected, despite previously reported anti-oxidative properties of DMG. Furthermore, no significant impact on reproductive performance could be recorded. In conclusion, DMG supplementation significantly improved nutrient digestibility. Possible beneficial effects on energy metabolism and reproductive performance of sows should be tested when DMG is supplemented for a longer

  4. Ethylene production in relation to nitrogen metabolism in Saccharomyces cerevisiae.

    Science.gov (United States)

    Johansson, Nina; Persson, Karl O; Quehl, Paul; Norbeck, Joakim; Larsson, Christer

    2014-11-01

    We have previously shown that ethylene production in Saccharomyces cerevisiae expressing the ethylene-forming enzyme (EFE) from Pseudomonas syringae is strongly influenced by variations in the mode of cultivation as well as the choice of nitrogen source. Here, we have studied the influence of nitrogen metabolism on the production of ethylene further. Using ammonium, glutamate, glutamate/arginine, and arginine as nitrogen sources, it was found that glutamate (with or without arginine) correlates with a high ethylene production, most likely linked to an observed increase in 2-oxoglutarate levels. Arginine as a sole nitrogen source caused a reduced ethylene production. A reduction of arginine levels, accomplished using an arginine auxotrophic ARG4-deletion strain in the presence of limiting amounts of arginine or through CAR1 overexpression, did however not correlate with an increased ethylene production. As expected, arginine was necessary for ethylene production as ethylene production in the ARG4-deletion strain ceased at the time when arginine was depleted. In conclusion, our data suggest that high levels of 2-oxoglutarate and a limited amount of arginine are required for successful ethylene production in yeast. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  5. Digestion, Excretion and Metabolism, Science (Experimental): 5346.03.

    Science.gov (United States)

    Weiss, Alan; And Others

    This unit of instruction deals with a study of human physiology with emphasis on the process of digestion. The urinary system and urinary disorders are also discussed. The course is for the interested student and requires credit or background in previous biology programs. It is, in part, a second course in biology, but it is well within the range…

  6. Comparison based on environmental effects of nitrogen management techniques in a manure digestate case study.

    Science.gov (United States)

    Paccanelli, Nicola; Teli, Aronne; Scaglione, Davide; Insabato, Gabriele; Casula, Alessandro

    2015-01-01

    Due to climate issues and favourable energy market, biogas is spreading as a manure management technique. Digestate is rich in nutrient and has to be handled in order to respect the 'nitrate directive' that limits nitrogen field application in areas defined as vulnerable. In this study, we compared different nitrogen management scenarios: a non-treatment option, a biological short-cut nitrification, a complete autotrophic process (anammox) and ammonia stripping from membrane filtration concentrate. The environmental effect comparison was obtained with 'Cross media effects analysis' and life cycle assessment (LCA). The results were different in some aspects, especially the impacts on eutrophication. According to cross media, the best process is DENO 2, while LCA shows similar impacts for all techniques and the best solution would be the no-treatment option. The main reason to adopt a digestate treatment technique is the lack of area for a correct disposal. If LCA eutrophication results are multiplied with the hectares necessary for each technology, a result similar to that of cross media is obtained.

  7. Global changes in transcription orchestrate metabolic differentiation during symbiotic nitrogen fixation in Lotus japonicus

    DEFF Research Database (Denmark)

    Colebatch, Gillian; Desbrosses, Guilhem; Ott, Thomas

    2004-01-01

    Research on legume nodule metabolism has contributed greatly to our knowledge of primary carbon and nitrogen metabolism in plants in general, and in symbiotic nitrogen fixation in particular. However, most previous studies focused on one or a few genes/enzymes involved in selected metabolic...

  8. A holistic view of dietary carbohydrate utilization in lobster: digestion, postprandial nutrient flux, and metabolism.

    Science.gov (United States)

    Rodríguez-Viera, Leandro; Perera, Erick; Casuso, Antonio; Perdomo-Morales, Rolando; Gutierrez, Odilia; Scull, Idania; Carrillo, Olimpia; Martos-Sitcha, Juan A; García-Galano, Tsai; Mancera, Juan Miguel

    2014-01-01

    Crustaceans exhibit a remarkable variation in their feeding habits and food type, but most knowledge on carbohydrate digestion and utilization in this group has come from research on few species. The aim of this study was to make an integrative analysis of dietary carbohydrate utilization in the spiny lobster Panulirus argus. We used complementary methodologies such as different assessments of digestibility, activity measurements of digestive and metabolic enzymes, and post-feeding flux of nutrients and metabolites. Several carbohydrates were well digested by the lobster, but maize starch was less digestible than all other starches studied, and its inclusion in diet affected protein digestibility. Most intense hydrolysis of carbohydrates in the gastric chamber of lobster occurred between 2-6 h after ingestion and afterwards free glucose increased in hemolymph. The inclusion of wheat in diet produced a slow clearance of glucose from the gastric fluid and a gradual increase in hemolymph glucose. More intense hydrolysis of protein in the gastric chamber occurred 6-12 h after ingestion and then amino acids tended to increase in hemolymph. Triglyceride concentration in hemolymph rose earlier in wheat-fed lobsters than in lobsters fed other carbohydrates, but it decreased the most 24 h later. Analyses of metabolite levels and activities of different metabolic enzymes revealed that intermolt lobsters had a low capacity to store and use glycogen, although it was slightly higher in wheat-fed lobsters. Lobsters fed maize and rice diets increased amino acid catabolism, while wheat-fed lobsters exhibited higher utilization of fatty acids. Multivariate analysis confirmed that the type of carbohydrate ingested had a profound effect on overall metabolism. Although we found no evidence of a protein-sparing effect of dietary carbohydrate, differences in the kinetics of their digestion and absorption impacted lobster metabolism determining the fate of other nutrients.

  9. A holistic view of dietary carbohydrate utilization in lobster: digestion, postprandial nutrient flux, and metabolism.

    Directory of Open Access Journals (Sweden)

    Leandro Rodríguez-Viera

    Full Text Available Crustaceans exhibit a remarkable variation in their feeding habits and food type, but most knowledge on carbohydrate digestion and utilization in this group has come from research on few species. The aim of this study was to make an integrative analysis of dietary carbohydrate utilization in the spiny lobster Panulirus argus. We used complementary methodologies such as different assessments of digestibility, activity measurements of digestive and metabolic enzymes, and post-feeding flux of nutrients and metabolites. Several carbohydrates were well digested by the lobster, but maize starch was less digestible than all other starches studied, and its inclusion in diet affected protein digestibility. Most intense hydrolysis of carbohydrates in the gastric chamber of lobster occurred between 2-6 h after ingestion and afterwards free glucose increased in hemolymph. The inclusion of wheat in diet produced a slow clearance of glucose from the gastric fluid and a gradual increase in hemolymph glucose. More intense hydrolysis of protein in the gastric chamber occurred 6-12 h after ingestion and then amino acids tended to increase in hemolymph. Triglyceride concentration in hemolymph rose earlier in wheat-fed lobsters than in lobsters fed other carbohydrates, but it decreased the most 24 h later. Analyses of metabolite levels and activities of different metabolic enzymes revealed that intermolt lobsters had a low capacity to store and use glycogen, although it was slightly higher in wheat-fed lobsters. Lobsters fed maize and rice diets increased amino acid catabolism, while wheat-fed lobsters exhibited higher utilization of fatty acids. Multivariate analysis confirmed that the type of carbohydrate ingested had a profound effect on overall metabolism. Although we found no evidence of a protein-sparing effect of dietary carbohydrate, differences in the kinetics of their digestion and absorption impacted lobster metabolism determining the fate of other

  10. Níveis de proteína em suplementos para terminação de bovinos em pastejo durante o período de transição Seca/Águas: digestibilidade aparente e parâmetros do metabolismo ruminal e dos compostos nitrogenados Effects of feeding different protein levels of supplements to finishing cattle in pasture during the dry to rainy transition season on apparent digestibility and metabolism of ruminal and nitrogenous compounds

    Directory of Open Access Journals (Sweden)

    Edenio Detmann

    2005-08-01

    Full Text Available Avaliaram-se aspectos das digestibilidades aparente total e parcial e parâmetros do metabolismo ruminal e dos compostos nitrogenados em novilhos mestiços suplementados durante a fase de transição entre os períodos seco e chuvoso. Foram utilizados cinco novilhos mestiços holandês x zebu com idade e peso médios iniciais de 24 meses e 304 kg, manejados em cinco piquetes de B. decumbens (0,34 ha. Foram fornecidos suplementos (4 kg/animal/dia constituídos por fubá de milho, grão de soja integral, uréia, sulfato de amônia e mistura mineral, sendo formulados para apresentarem níveis de 12; 16; 20 e 24% de proteína bruta (PB, com base na matéria natural. O experimento foi conduzido em quatro períodos experimentais de 21 dias, sendo analisado por delineamento em quadrado latino 4x4. O quinto animal foi mantido sem suplementação e utilizado como medida de comparação descritiva (SAL. Não foram observados efeitos da composição dos suplementos sobre a digestibilidade total e parcial da matéria seca, matéria orgânica (MO e fibra em detergente neutro e sobre os fluxos abomasais de nitrogênio (N total, amoniacal e microbiano (NMIC. Os níveis de N amoniacal ruminal foram incrementados linearmente pela elevação dos níveis de PB dos suplementos. A eficiência de síntese microbiana apresentou valor médio de 17,5 g NMIC/kg MO fermentada no rúmen (MOFR para os suplementos, sendo superior a SAL (10,6 g NMIC/kg MOFR. A elevação dos níveisThe objective of this trial was to evaluate ruminal, intestinal, and total tract apparent digestibilities of nutrients as well as metabolism of ruminal and nitrogenous compounds in supplemented finishing cattle during the drought to rainy transition season. Five Holstein x Zebu steers averaging 304 kg of live weight and 24 months of age located in five paddocks (0.34 ha each of Brachiaria decumbens were used in this trial. The supplements fed (4 kg/animal/day contained ground corn, whole soybean

  11. Carbohydrates digestion and metabolism in the spiny lobster (Panulirus argus): biochemical indication for limited carbohydrate utilization.

    Science.gov (United States)

    Rodríguez-Viera, Leandro; Perera, Erick; Montero-Alejo, Vivian; Perdomo-Morales, Rolando; García-Galano, Tsai; Martínez-Rodríguez, Gonzalo; Mancera, Juan M

    2017-01-01

    As other spiny lobsters, Panulirus argus is supposed to use preferentially proteins and lipids in energy metabolism, while carbohydrates are well digested but poorly utilized. The aim of this study was to evaluate the effect of dietary carbohydrate level on digestion and metabolism in the spiny lobster P. argus . We used complementary methodologies such as post-feeding flux of nutrients and metabolites, as well as measurements of α-amylase expression and activity in the digestive tract. Lobsters readily digested and absorbed carbohydrates with a time-course that is dependent on their content in diet. Lobster showed higher levels of free glucose and stored glycogen in different tissues as the inclusion of wheat flour increased. Modifications in intermediary metabolism revealed a decrease in amino acids catabolism coupled with a higher use of free glucose as carbohydrates rise up to 20%. However, this effect seems to be limited by the metabolic capacity of lobsters to use more than 20% of carbohydrates in diets. Lobsters were not able to tightly regulate α-amylase expression according to dietary carbohydrate level but exhibited a marked difference in secretion of this enzyme into the gut. Results are discussed to highlight the limitations to increasing carbohydrate utilization by lobsters. Further growout trials are needed to link the presented metabolic profiles with phenotypic outcomes.

  12. Carbohydrates digestion and metabolism in the spiny lobster (Panulirus argus: biochemical indication for limited carbohydrate utilization

    Directory of Open Access Journals (Sweden)

    Leandro Rodríguez-Viera

    2017-11-01

    Full Text Available As other spiny lobsters, Panulirus argus is supposed to use preferentially proteins and lipids in energy metabolism, while carbohydrates are well digested but poorly utilized. The aim of this study was to evaluate the effect of dietary carbohydrate level on digestion and metabolism in the spiny lobster P. argus. We used complementary methodologies such as post-feeding flux of nutrients and metabolites, as well as measurements of α-amylase expression and activity in the digestive tract. Lobsters readily digested and absorbed carbohydrates with a time-course that is dependent on their content in diet. Lobster showed higher levels of free glucose and stored glycogen in different tissues as the inclusion of wheat flour increased. Modifications in intermediary metabolism revealed a decrease in amino acids catabolism coupled with a higher use of free glucose as carbohydrates rise up to 20%. However, this effect seems to be limited by the metabolic capacity of lobsters to use more than 20% of carbohydrates in diets. Lobsters were not able to tightly regulate α-amylase expression according to dietary carbohydrate level but exhibited a marked difference in secretion of this enzyme into the gut. Results are discussed to highlight the limitations to increasing carbohydrate utilization by lobsters. Further growout trials are needed to link the presented metabolic profiles with phenotypic outcomes.

  13. Digestibility and behavior of dogs housed in kennels or metabolic cages

    Directory of Open Access Journals (Sweden)

    Tabyta Tamara Sabchuk

    2012-01-01

    Full Text Available The objective of the present study was to compare the apparent digestibility coefficients of a commercial dog food, fecal consistency and behavior of dogs housed in kennels and metabolic cages. Six adult Beagle dogs were distributed in cross-over experimental design, with six replicates per treatment. Dogs were housed in two environments: metabolic cages and in masonry kennels with solarium. Dogs were fed for a five-day adaptation period, and the five following days were used for total feces collection. Dogs behavior was recorded during a 48-h period, with 10-min intervals. Apparent digestibility coefficients were not different between treatments. However, dogs housed in metabolic cages produced lower weight and more consistent feces as compared with dogs housed in kennels. Dogs spent most of the time sleeping in both housing systems; however, dogs housed in the metabolic cages slept more than those in kennels. Stress-related behaviors (barking, whimpering, stereotypies, etc were observed for no longer than 15 minutes per day, and were not different between dogs in kennels or in cages. There is no difference in food digestibility evaluated in dogs housed in metabolic cages or kennels; however, dogs kept in metabolic cages eliminate drier feces and spend more time inactive than those kept in kennels.

  14. Replacing lactose from calf milk replacers : effects on digestion and post-absorptive metabolism

    NARCIS (Netherlands)

    Gilbert, M.S.

    2015-01-01

    Summary PhD thesis Myrthe S. Gilbert

    Replacing lactose from calf milk replacers – Effects on digestion and post-absorptive metabolism

    Veal calves are fed milk replacer (MR) and solid feed. The largest part of the energy provided to veal calves

  15. Nitrogen availability and indirect measurements of greenhouse gas emissions from aerobic and anaerobic biowaste digestates applied to agricultural soils

    Energy Technology Data Exchange (ETDEWEB)

    Rigby, H.; Smith, S.R., E-mail: s.r.smith@imperial.ac.uk

    2013-12-15

    Highlights: • Nitrogen release in digestate-amended soil depends on the digestate type. • Overall N release is modulated by digestate mineral and mineralisable N contents. • Microbial immobilisation does not influence overall release of digestate N in soil. • Digestate physical properties and soil type interact to affect overall N recovery. • High labile C inputs in digestate may promote denitrification in fine-textured soil. - Abstract: Recycling biowaste digestates on agricultural land diverts biodegradable waste from landfill disposal and represents a sustainable source of nutrients and organic matter (OM) to improve soil for crop production. However, the dynamics of nitrogen (N) release from these organic N sources must be determined to optimise their fertiliser value and management. This laboratory incubation experiment examined the effects of digestate type (aerobic and anaerobic), waste type (industrial, agricultural and municipal solid waste or sewage sludge) and soil type (sandy loam, sandy silt loam and silty clay) on N availability in digestate-amended soils and also quantified the extent and significance of the immobilisation of N within the soil microbial biomass, as a possible regulatory mechanism of N release. The digestate types examined included: dewatered, anaerobically digested biosolids (DMAD); dewatered, anaerobic mesophilic digestate from the organic fraction of municipal solid waste (DMADMSW); liquid, anaerobic co-digestate of food and animal slurry (LcoMAD) and liquid, thermophilic aerobic digestate of food waste (LTAD). Ammonium chloride (NH{sub 4}Cl) was included as a reference treatment for mineral N. After 48 days, the final, maximum net recoveries of mineral N relative to the total N (TN) addition in the different digestates and unamended control treatments were in the decreasing order: LcoMAD, 68%; LTAD, 37%, DMAD, 20%; and DMADMSW, 11%. A transient increase in microbial biomass N (MBN) was observed with LTAD application

  16. Nitrogen availability and indirect measurements of greenhouse gas emissions from aerobic and anaerobic biowaste digestates applied to agricultural soils

    International Nuclear Information System (INIS)

    Rigby, H.; Smith, S.R.

    2013-01-01

    Highlights: • Nitrogen release in digestate-amended soil depends on the digestate type. • Overall N release is modulated by digestate mineral and mineralisable N contents. • Microbial immobilisation does not influence overall release of digestate N in soil. • Digestate physical properties and soil type interact to affect overall N recovery. • High labile C inputs in digestate may promote denitrification in fine-textured soil. - Abstract: Recycling biowaste digestates on agricultural land diverts biodegradable waste from landfill disposal and represents a sustainable source of nutrients and organic matter (OM) to improve soil for crop production. However, the dynamics of nitrogen (N) release from these organic N sources must be determined to optimise their fertiliser value and management. This laboratory incubation experiment examined the effects of digestate type (aerobic and anaerobic), waste type (industrial, agricultural and municipal solid waste or sewage sludge) and soil type (sandy loam, sandy silt loam and silty clay) on N availability in digestate-amended soils and also quantified the extent and significance of the immobilisation of N within the soil microbial biomass, as a possible regulatory mechanism of N release. The digestate types examined included: dewatered, anaerobically digested biosolids (DMAD); dewatered, anaerobic mesophilic digestate from the organic fraction of municipal solid waste (DMADMSW); liquid, anaerobic co-digestate of food and animal slurry (LcoMAD) and liquid, thermophilic aerobic digestate of food waste (LTAD). Ammonium chloride (NH 4 Cl) was included as a reference treatment for mineral N. After 48 days, the final, maximum net recoveries of mineral N relative to the total N (TN) addition in the different digestates and unamended control treatments were in the decreasing order: LcoMAD, 68%; LTAD, 37%, DMAD, 20%; and DMADMSW, 11%. A transient increase in microbial biomass N (MBN) was observed with LTAD application

  17. Nitrogen mineralization from anaerobically digested centrifuge cake and aged air-dried biosolids.

    Science.gov (United States)

    Kumar, Kuldip; Hundal, Lakhwinder S; Cox, Albert E; Granato, Thomas

    2014-09-01

    This study was conducted to estimate nitrogen (N) mineralization of anaerobically digested centrifuge cake from the Stickney Water Reclamation Plant (SWRP) and Calumet Water Reclamation Plant (CWRP), lagoon-aged air-dried biosolids from the CWRP, and Milorganite at three rates of application (0, 12.5 and 25 Mg ha(-1)). The N mineralized varied among biosolids as follows: Milorganite (44%) > SWRP centrifuge cake (35%) > CWRP centrifuge cake (31%) > aged air-dried (13%). The N mineralized in the SWRP cake (32%) and CWRP aged air-dried biosolids (12%) determined from the 15N study were in agreement with the first study. The N mineralization value for centrifuge cake biosolids observed in our study is higher than the value given in the Part 503 rule and Illinois Part 391 guidelines. These results will be used to fine-tune biosolids application rate to match crop N demand without compromising yield while minimizing any adverse effect on the environment.

  18. Factors affecting levels of some phenolic compounds, digestibility, and nitrogen content of the mature leaves ofBarteria fistulosa (Passifloraceae).

    Science.gov (United States)

    Waterman, P G; Ross, J A; McKey, D B

    1984-03-01

    Levels of total phenolics, condensed tannins, acid detergent fiber, pepsin/cellulase digestibility, and nitrogen in mature leaves of 26 individuals of the ant-plant,Barteria fistulosa, have been determined. Analysis of the results in terms of the presence or absence of ants and the position of the branch from which the leaves were collected showed no relationship with concentrations of phenolics or fiber and only a weak relationship with digestibility and nitrogen. By contrast, light intensity strongly influenced levels of phenolics, notably condensed tannins, so that mature leaves of individuals growing in direct sunlight were less digestible and appeared to be of lower quality as food for herbivores than did mature leaves of individuals in shaded positions. Possible reasons for the variation in condensed tannin levels are discussed.

  19. Bromatological composition and dry matter digestibility of millet cultivars subjected to nitrogen doses

    Directory of Open Access Journals (Sweden)

    W.H.D. Buso

    2014-06-01

    Full Text Available The bromatological composition and in vitro dry matter digestibility of millet cultivars were assessed for different nitrogen doses and two sowing seasons in the Ceres municipality of Goiás state, Brazil. The treatments consisted of three millet cultivars (ADR-7010, ADR-500 and BRS-1501, four nitrogen (N doses (0, 50, 100 and 200kg ha-1 of N and two sowing seasons. Three replicates and a randomised block design with a 3 x 4 x 2 factorial scheme were used. Two cuttings were performed in each season when plants reached an average height of 0.70 cm. No significant interactions were observed between or among cultivars for N doses and dry matter (DM, crude protein (CP, neutral detergent fibre (NDF and acid detergent fibre (ADF contents. The DM, CP, NDF and ADF contents were significantly different between N doses. The DM and CP contents increased as the N dose increased to 100kg ha-1. The maximum DM and CP contents were 11.14 and 22.53%, respectively. The NDF and ADF contents were higher in the control treatment (60.11 and 30.01%, respectively. In addition, the lowest ADF and NDF concentrations occurred at an N dose of 50kg ha-1 (56.33 and 30.23%, respectively. The DM contents were higher for the February sowing, with an average of 10.59%. The highest CP and ADF contents were found for the December sowing (22.46 and 31.58%, respectively. No significant differences were found for millet cultivars, N doses or sowing seasons. A significant interaction was found between sowing season and millet cultivar. The BRS-1501 cultivar had a higher in vitro dry matter digestibility in the December/2010 sowing (73.88%.

  20. Dynamic optimal metabolic control theory: a cybernetic approach for modelling of the central nitrogen metabolism of S. cerevisiae

    NARCIS (Netherlands)

    Riel, van N.A.W.; Giuseppin, M.L.F.; Verrips, C.T.

    2000-01-01

    The theory of dynamic optimal metabolic control (DOMC), as developed by Giuseppin and Van Riel (Metab. Eng., 2000), is applied to model the central nitrogen metabolism (CNM) in Saccharomyces cerevisiae. The CNM represents a typical system encountered in advanced metabolic engineering. The CNM is the

  1. [Rehabilitation for digestive and metabolic diseases. Quo vadis?].

    Science.gov (United States)

    Stockbrugger, R; Rosemeyer, D; Armbrecht, U

    2010-10-01

    The position of rehabilitation in gastroenterology, hepatology and metabolic diseases has changed little in the last 25 years. Initial improvements in quality are oriented more to the content of rehabilitative measures and less to organizational basic conditions. Nevertheless, there is an urgent need for action if rehabilitation medicine is to achieve an equivalent and recognized position in the interaction between primary care and other medical specialties. In this article suggestions for expedient prerequisites and utilization options of rehabilitation in the fields of hepatogastroenterology and metabolism will be presented, which are also oriented to the exemplary implemented concepts from Sweden and The Netherlands.

  2. Respiration and nitrogen assimilation: targeting mitochondria-associated metabolism as a means to enhance nitrogen use efficiency.

    Science.gov (United States)

    Foyer, Christine H; Noctor, Graham; Hodges, Michael

    2011-02-01

    Considerable advances in our understanding of the control of mitochondrial metabolism and its interactions with nitrogen metabolism and associated carbon/nitrogen interactions have occurred in recent years, particularly highlighting important roles in cellular redox homeostasis. The tricarboxylic acid (TCA) cycle is a central metabolic hub for the interacting pathways of respiration, nitrogen assimilation, and photorespiration, with components that show considerable flexibility in relation to adaptations to the different functions of mitochondria in photosynthetic and non-photosynthetic cells. By comparison, the operation of the oxidative pentose phosphate pathway appears to represent a significant limitation to nitrogen assimilation in non-photosynthetic tissues. Valuable new insights have been gained concerning the roles of the different enzymes involved in the production of 2-oxoglutarate (2-OG) for ammonia assimilation, yielding an improved understanding of the crucial role of cellular energy balance as a broker of co-ordinate regulation. Taken together with new information on the mechanisms that co-ordinate the expression of genes involved in organellar functions, including energy metabolism, and the potential for exploiting the existing flexibility for NAD(P)H utilization in the respiratory electron transport chain to drive nitrogen assimilation, the evidence that mitochondrial metabolism and machinery are potential novel targets for the enhancement of nitrogen use efficiency (NUE) is explored.

  3. Influence of nitrogen deficiency on the metabolism of photoassimilated 14C in sunflower

    International Nuclear Information System (INIS)

    Stanev, V.; Angelov, M.; Popov, G.

    1981-01-01

    In experiments carried out on sunflower the specific changes in the metabolism of photoassimilated 14 C caused by nitrogen deficiency are investigated. The data presented show that nitrogen deficiency in sunflower inhibits the metabolism of photoassimilated 14 C through phosphoglyceric acid and phosphoenolpyruvate and directs it to a great extent through hexo-monophosphates towards the hydrocarbons-sucrose and starch. (authors)

  4. Microbiological Diversity Demonstrates the Potential which Collaboratively Metabolize Nitrogen Oxides ( NOx) under Smog Environmental Stress

    Science.gov (United States)

    Chen, X. Z.; Zhao, X. H.; Chen, X. P.

    2018-03-01

    Recently, smoggy weather has become a daily in large part of China because of rapidly economic growth and accelerative urbanization. Stressed on the smoggy situation and economic growth, the green and environment-friendly technology is necessary to reduce or eliminate the smog and promote the sustainable development of economy. Previous studies had confirmed that nitrogen oxides ( NOx ) is one of crucial factors which forms smog. Microorganisms have the advantages of quickly growth and reproduction and metabolic diversity which can collaboratively Metabolize various NOx. This study will design a kind of bacteria & algae cultivation system which can metabolize collaboratively nitrogen oxides in air and intervene in the local nitrogen cycle. Furthermore, the nitrogen oxides can be transformed into nitrogen gas or assembled in protein in microorganism cell by regulating the microorganism types and quantities and metabolic pathways in the system. Finally, the smog will be alleviated or eliminated because of reduction of nitrogen oxides emission. This study will produce the green developmental methodology.

  5. Food composition influences metabolism, heart rate and organ growth during digestion in Python regius.

    Science.gov (United States)

    Henriksen, Poul Secher; Enok, Sanne; Overgaard, Johannes; Wang, Tobias

    2015-05-01

    Digestion in pythons is associated with a large increase in oxygen consumption (SDA), increased cardiac output and growth in visceral organs assisting in digestion. The processes leading to the large postprandial rise in metabolism in snakes is subject to opposing views. Gastric work, protein synthesis and organ growth have each been speculated to be major contributors to the SDA. To investigate the role of food composition on SDA, heart rate (HR) and organ growth, 48 ball pythons (Python regius) were fed meals of either fat, glucose, protein or protein combined with carbonate. Our study shows that protein, in the absence or presence of carbonate causes a large SDA response, while glucose caused a significantly smaller SDA response and digestion of fat failed to affect metabolism. Addition of carbonate to the diet to stimulate gastric acid secretion did not increase the SDA response. These results support protein synthesis as a major contributor to the SDA response and show that increased gastric acid secretion occurs at a low metabolic cost. The increase in metabolism was supported by tachycardia caused by altered autonomic regulation as well as an increased non-adrenergic, non-cholinergic (NANC) tone in response to all diets, except for the lipid meal. Organ growth only occurred in the small intestine and liver in snakes fed on a high protein diet. Copyright © 2014 Elsevier Inc. All rights reserved.

  6. Nitrogen removal from sludge digester liquids by nitrification/denitrification or partial nitritation/anammox: environmental and economical considerations.

    Science.gov (United States)

    Fux, C; Siegrist, H

    2004-01-01

    In wastewater treatment plants with anaerobic sludge digestion, 15-20% of the nitrogen load is recirculated to the main stream with the return liquors from dewatering. Separate treatment of this ammonium-rich digester supernatant significantly reduces the nitrogen load of the activated sludge system. Two biological applications are considered for nitrogen elimination: (i) classical autotrophic nitrification/heterotrophic denitrification and (ii) partial nitritation/autotrophic anaerobic ammonium oxidation (anammox). With both applications 85-90% nitrogen removal can be achieved, but there are considerable differences in terms of sustainability and costs. The final gaseous products for heterotrophic denitrification are generally not measured and are assumed to be nitrogen gas (N2). However, significant nitrous oxide (N2O) production can occur at elevated nitrite concentrations in the reactor. Denitrification via nitrite instead of nitrate has been promoted in recent years in order to reduce the oxygen and the organic carbon requirements. Obviously this "achievement" turns out to be rather disadvantageous from an overall environmental point of view. On the other hand no unfavorable intermediates are emitted during anaerobic ammonium oxidation. A cost estimate for both applications demonstrates that partial nitritation/anammox is also more economical than classical nitrification/denitrification. Therefore autotrophic nitrogen elimination should be used in future to treat ammonium-rich sludge liquors.

  7. Studies with nitrogen-15-labelled amino acids for a quantitative description of nitrogen metabolism in man

    International Nuclear Information System (INIS)

    Hartig, W.; Faust, H.; Czarnetzki, H.D.; Winkler, E.; Akademie der Wissenschaften der DDR, Leipzig. Zentralinstitut fuer Isotopen- und Strahlenforschung)

    1977-01-01

    The utilization of glycine in healthy and stressed persons has been studied by continuous infusion or oral administration. The results of our studies show that (1) Breakdown of protein is increased in stress conditions; (2) Amino acids are also synthesized to protein in stress, the percentage of amino acids used for synthesis being smaller in stress conditions; (3) The urea synthesis during stress is increased and accelerated; (4) In the isotopic steady state 23% of the 15 N-glycine administered by infusion to healthy persons and 41% of the amount administered to patients after cholecystectomy is eliminated (urea 16%/26%; ammonia 4%/5%); using a single oral dose 24% is eliminated as total N after 24h (19% as 15 N-urea and 4% as 15 N-ammonia); (5) Depending on the method of gastric surgery the absorption and elimination rate of glycine-N varied; the more rapid intestinal absorption of glycine in comparison with healthy persons leads to a higher 15 N elimination via urine, and causes a disturbance of the nitrogen metabolism and nitrogen balance. (author)

  8. Effect of formaldehyde-treated urea on rumen fermentation, ration digestibility and nitrogen utilization

    Directory of Open Access Journals (Sweden)

    Jouko Setälä

    1982-01-01

    Full Text Available The study comprises two experiments in which young Finn-sheep were used as test animals. The experimental rations consisted of equal parts of NaOH-treated wheat (Exp. 1 or barley (Exp. 2 straw and a concentrate mixture of barley-molassed beet pulp (Exp. 1 or barley-oats-molassed beet pulp (Exp.2. Feeding was performed twice a day. In addition 20 grams of urea/animal/day was mixed into the concentrates just before feeding. The urea was treated with the following percentages of formaldehyde, on a weight basis: 0 (F0, 1.0 (F1.0, 3.0(F3.0 and 5.0(F5.0 in Exp. 1 and 0, 1.0 and 1.5(F1.5 in Exp. 2. The digestibility of the total ration decreased, when F3.0 and F5.0 urea was used, but the decrease was significant (P< 0.05 only when the apparent digestibility of crude protein was compared between the F0 and F5.0 diets. The amount of rumen bacteria was decreased (P< 0.05 and the amount of protozoa increased (P< 0.01 by formaldehyde treatment levels above F1.0 and F3.0, respectively. The concentration of the total VFA in the rumen tended to decrease with treatment levels higher than F3.0. No significant differences were found in the composition of the VFA. When treated urea was used, the excretion of nitrogen in the faeces increased but its excretion in the urine decreased. The percentage retention of the nitrogen ingested by the animals on diets F0, F1.0, F3.0, and F5.0 in Exp. 1 was 15.0, 10.8, 13.2 and 12.2 and on diets F0, F1.0 and F1.5 in Exp. 2 it was 20.5, 20.2 and 21.2, respectively.

  9. Urea and Ammonia Metabolism and the Control of Renal Nitrogen Excretion

    Science.gov (United States)

    Mitch, William E.; Sands, Jeff M.

    2015-01-01

    Renal nitrogen metabolism primarily involves urea and ammonia metabolism, and is essential to normal health. Urea is the largest circulating pool of nitrogen, excluding nitrogen in circulating proteins, and its production changes in parallel to the degradation of dietary and endogenous proteins. In addition to serving as a way to excrete nitrogen, urea transport, mediated through specific urea transport proteins, mediates a central role in the urine concentrating mechanism. Renal ammonia excretion, although often considered only in the context of acid-base homeostasis, accounts for approximately 10% of total renal nitrogen excretion under basal conditions, but can increase substantially in a variety of clinical conditions. Because renal ammonia metabolism requires intrarenal ammoniagenesis from glutamine, changes in factors regulating renal ammonia metabolism can have important effects on glutamine in addition to nitrogen balance. This review covers aspects of protein metabolism and the control of the two major molecules involved in renal nitrogen excretion: urea and ammonia. Both urea and ammonia transport can be altered by glucocorticoids and hypokalemia, two conditions that also affect protein metabolism. Clinical conditions associated with altered urine concentrating ability or water homeostasis can result in changes in urea excretion and urea transporters. Clinical conditions associated with altered ammonia excretion can have important effects on nitrogen balance. PMID:25078422

  10. Nitrogen Metabolism in Adaptation of Photosynthesis to Water Stress in Rice Grown under Different Nitrogen Levels

    Directory of Open Access Journals (Sweden)

    Chu Zhong

    2017-06-01

    Full Text Available To investigate the role of nitrogen (N metabolism in the adaptation of photosynthesis to water stress in rice, a hydroponic experiment supplying with low N (0.72 mM, moderate N (2.86 mM, and high N (7.15 mM followed by 150 g⋅L-1 PEG-6000 induced water stress was conducted in a rainout shelter. Water stress induced stomatal limitation to photosynthesis at low N, but no significant effect was observed at moderate and high N. Non-photochemical quenching was higher at moderate and high N. In contrast, relative excessive energy at PSII level (EXC was declined with increasing N level. Malondialdehyde and hydrogen peroxide (H2O2 contents were in parallel with EXC. Water stress decreased catalase and ascorbate peroxidase activities at low N, resulting in increased H2O2 content and severer membrane lipid peroxidation; whereas the activities of antioxidative enzymes were increased at high N. In accordance with photosynthetic rate and antioxidative enzymes, water stress decreased the activities of key enzymes involving in N metabolism such as glutamate synthase and glutamate dehydrogenase, and photorespiratory key enzyme glycolate oxidase at low N. Concurrently, water stress increased nitrate content significantly at low N, but decreased nitrate content at moderate and high N. Contrary to nitrate, water stress increased proline content at moderate and high N. Our results suggest that N metabolism appears to be associated with the tolerance of photosynthesis to water stress in rice via affecting CO2 diffusion, antioxidant capacity, and osmotic adjustment.

  11. Fertilizer performance of liquid fraction of digestate as synthetic nitrogen substitute in silage maize cultivation for three consecutive years.

    Science.gov (United States)

    Sigurnjak, I; Vaneeckhaute, C; Michels, E; Ryckaert, B; Ghekiere, G; Tack, F M G; Meers, E

    2017-12-01

    Following changes over recent years in fertilizer legislative framework throughout Europe, phosphorus (P) is taking over the role of being the limiting factor in fertilizer application rate of animal manure. This results in less placement area for spreading animal manure. As a consequence, more expensive and energy demanding synthetic fertilizers are required to meet crop nutrient requirements despite existing manure surpluses. Anaerobic digestion followed by mechanical separation of raw digestate, results in liquid fraction (LF) of digestate, a product poor in P but rich in nitrogen (N) and potassium (K). A 3-year field experiment was conducted to evaluate the impact of using the LF of digestate as a (partial) substitute for synthetic N fertilizer. Two different fertilization strategies, the LF of digestate in combination with respectively animal manure and digestate, were compared to the conventional fertilization regime of raw animal manure with synthetic fertilizers. Results from the 3-year trial indicate that the LF of digestate may substitute synthetic N fertilizers without crop yield losses. Through fertilizer use efficiency assessment it was observed that under-fertilization of soils with a high P status could reduce P availability and consequently the potential for P leaching. Under conditions of lower K application, more sodium was taken up by the crop. In arid regions, this effect might reduce the potential risk of salt accumulation that is associated with organic fertilizer application. Finally, economic and ecological benefits were found to be higher when LF of digestate was used as a synthetic N substitute. Future perspectives indicate that nutrient variability in bio-based fertilizers will be one of the greatest challenges to address in the future utilization of these products. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Digestibility and nitrogen balance of lambs fed sugarcane hydrolyzed under different conditions as roughage in the diet

    Directory of Open Access Journals (Sweden)

    Viviane Endo

    2015-02-01

    Full Text Available This study aimed to evaluate the digestibility and nitrogen balance (NB of lambs fed sugarcane hydrolyzed under different conditions. Fifteen Ile de France lambs at, on average, 23.5kg of body weight were evaluated. Treatments were: in natura sugarcane (IN, sugarcane hydrolyzed using 0.6% calcium oxide (CaO under aerobic condition (AER, and sugarcane hydrolyzed using 0.6% CaO under anaerobic condition (ANA. Therefore, a completely randomized design was constituted with five replicates per treatment. Treatments were supplied to animals along with concentrate. Both hydrolysis conditions aimed to alter the sugarcane fermentation pattern, therefore improving fiber digestibility. Lambs were housed in individual pens and fed with diet allowing 10% of refusals. Refusals, feces and urine were sampled daily during five days. They were collected to determine the digestibility and NB. A higher digestibility of neutral detergent fiber corrected for ash and protein (57.05%, organic matter (85.39%, hemicellulose (72.09%, NB (29.46g day-1 and 2.78g kg-0.75 day-1 and rate of nitrogen absorbed (3.00g kg-0.75 day-1 were observed for lambs fed with ANA than for those fed IN (41.17%, 73.76%, 53.80%, 21.39g day-1, 2.00g kg-0.75 day-1 and 2.22g kg-0.75 day-1, respectively. As roughage, ANA in the lamb diet, optimizes the nitrogen balance and is more efficient to improve the digestibility of some nutrients compared to IN. Whereas AER was as efficient as ANA and IN

  13. The nutritional quality of herbaceous legumes on goats: Intake, digestibility and nitrogen balances

    Directory of Open Access Journals (Sweden)

    Simon P Ginting

    2005-12-01

    Full Text Available The availability of forages is a critical factor that determine the sustainability of the animal-plantation production system. In this typical production system, cover crops could be an important sources of forages to support the animal production. The study is aimed to evaluate the nutritional quality (chemical compositions, intake, digestibility and N balances of herbaceous legumes namely Arachis pintoi and Arachis glabrata having potential for used as alternative cover crops in plantation. Centerocema pubescens, a conventional cover crops used in plantation, was used as control. Twenty-one mature male goats (16-18 kg were used in this experiment. The animals were put in individual metabolism cages, divided into three groups (7 animal per group based on the body weight, and were randomly allocated into one of the three forages. The experiment was run in a Completely Randomized Design. The animals were allocated to an adaptation period for 14 days, followed by intake measurement for 5 days and fecal and urine collection for the next 7 days. During the fecal and urine collection forages were offered at 90% of the maximum intake. Chemical analyses showed that the DM and OM contents were relatively equal among the forages, but the crude protein content of C. pubescens (23.56% are relatively higher than those of A. pintoi (16.94% or of A. glabrata (15.19% The fiber (NDF content was also relatively higher in C. pubescens (59.37% than in A. pintoi (16.94% or A. glabrata (41.50%. The forage intake was highest (P0.05 between goats fed A. pintoi (466 g/d or A. glabrata (453 g/d. A similar trend was seen when intake was expressed as % BW (3.80, 3.50 and 3.40, respectively or as g/kg BW0.75 (42.4, 39.5 and 38.4, respectively. The digestion coeficient of DM (81.3% or OM (83.5% were highest (P0.05 between A. glabrata (71.9 and 73.2%, respectively and C. pubescens (73.7 and 74.2%, respectively. The trends were the same with the digestion coeficient of ADF

  14. Nitrogen metabolism and protozoa production rate in cattle fed on diet containing protected protein

    International Nuclear Information System (INIS)

    Singh, G.P.; Gupta, B.N.

    1992-01-01

    Nitrogen metabolism and protozoa production rate using 14 C-choline as marker were studied on 9 adult male crossbred (Tharparker x Brown Swiss) rumen fistulated animals divided into 3 groups (A, B and C). All the animals were fed concentrate mixture and wheatstraw. However, groundnut cake (GNC) in concentrate mixture was untreated in group A, 50 per cent formaldehyde treated in group B and 100 per cent formaldehyde treated in group C. Although, DM intake was similar in these groups but water intake was significantly (P<0.05) higher in control group. Total-N, ammonia-N and blood urea were significantly lower in group B and C as compared to group A. Apparent CP digestibility was not affected by addition of formaldehyde treated GNC at 50 and 100 per cent levels. However, N balances increased significantly (P<0.05) due to addition of protected protein in diet. Protozoal pool as well as production rate were significantly (P<0.01) decreased due to formaldehyde treatment of GNC protein. Thus addition of formaldehyde treated GNC in diets decreased ammonia and protozoa production but increased N retention in groups B and C. (author). 27 refs., 3 tabs., 2 figs

  15. Effect of non-protein nitrogen and fodder legumes on the intake, digestibility and growth parameters of buffaloes

    International Nuclear Information System (INIS)

    Premaratne, S.

    1990-01-01

    Two in vivo digestibility studies and three nylon bag studies were conducted using four rumen fistulated male buffaloes to investigate the role of supplements of tree legumes and non-protein nitrogen on the feed intake, rumen function and growth of buffaloes given a basal diet of rice straw. Straw dry matter (DM) intake and digestibility were increased by urea treatment compared with urea supplementation. Inclusion of legume tree leaves in the diet increased the in vivo DM digestibility of both untreated and treated straw, but the increment was much higher for untreated straw. A supplementation of legumes also increased the in vivo nitrogen (N) digestibility of the diet of buffaloes. A trend towards an increase in straw intake with legume supplementation was also observed. Of the tree fodder legumes tested, Erythrina lithosperma had the highest potential for providing protein. Inclusion of legumes in the diet increased the DM and N degradation rates of feedstuff. In a growth trial of grazing female buffalo calves, the inclusion of fodder legumes increased the weight gain when compared with grazing alone. (author). 6 refs, 5 tabs

  16. Studies on nitrogen metabolism of soybean plants, (4)

    International Nuclear Information System (INIS)

    Kato, Yasumasa; Kitada, Subaru

    1979-01-01

    Nitrogen that came from cotyledons and nitrogen ( 15 N) pulse-fed at 5 different times during the growth of young soybean plants were studied for 33-days after germination. Cotyledons furnished nitrogen to primary leaves, stems, and roots for the first 8 days, but thereafter principally to 1 st and 2 nd trifoliate leaves. Redistribution of the cotyledon-derived nitrogen from primary leaves commenced from the 14 th day after germination when their total nitrogen was still increasing. At the end of the experiment, the cotyledon-derived nitrogen was distributed approximately uniformly among 6 expanded leaves, and very small amount was found in 3 immature leaves. It was shown that soybean leaves took up 15 N (via roots) throughout the entire period of their life, and from their near-mature stage onwards, uptake and redistribution of nitrogen were observed simultaneously. Thus, the nitrogen in mature leaves was partially being renewed constantly. Considering this fact, the nitrogen supplying capacity of soybean leaves was estimated to be about two times as large as that estimated conventionally from the net loss of nitrogen during their senescence. The turnover of leaf nitrogen was closely related to the turnover of leaf protein. Influx of nitrogen was invariably accompanied by the simultaneous synthesis of leaf protein, and conversely, efflux by the simultaneous breakdown of leaf protein. Sink removal (topping treatment) prevented the breakdown of leaf protein (as measured from the rate of release of label after the pulse feeding) as well as the export of nitrogen from the leaves. The nitrogen supplying function of soybean leaves was discussed in relation to the nitrogen and protein turnover of leaves. (Kaihara, S.)

  17. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory : evaluation of alkaline persulfate digestion as an alternative to Kjeldahl digestion for determination of total and dissolved nitrogen and phosphorus in water

    Science.gov (United States)

    Patton, Charles J.; Kryskalla, Jennifer R.

    2003-01-01

    Alkaline persulfate digestion was evaluated and validated as a more sensitive, accurate, and less toxic alternative to Kjeldahl digestion for routine determination of nitrogen and phosphorus in surface- and ground-water samples in a large-scale and geographically diverse study conducted by U.S. Geological Survey (USGS) between October 1, 2001, and September 30, 2002. Data for this study were obtained from about 2,100 surface- and ground-water samples that were analyzed for Kjeldahl nitrogen and Kjeldahl phosphorus in the course of routine operations at the USGS National Water Quality Laboratory (NWQL). These samples were analyzed independently for total nitrogen and total phosphorus using an alkaline persulfate digestion method developed by the NWQL Methods Research and Development Program. About half of these samples were collected during nominally high-flow (April-June) conditions and the other half were collected during nominally low-flow (August-September) conditions. The number of filtered and whole-water samples analyzed from each flow regime was about equal.By operational definition, Kjeldahl nitrogen (ammonium + organic nitrogen) and alkaline persulfate digestion total nitrogen (ammonium + nitrite + nitrate + organic nitrogen) are not equivalent. It was necessary, therefore, to reconcile this operational difference by subtracting nitrate + nitrite concentra-tions from alkaline persulfate dissolved and total nitrogen concentrations prior to graphical and statistical comparisons with dissolved and total Kjeldahl nitrogen concentrations. On the basis of two-population paired t-test statistics, the means of all nitrate-corrected alkaline persulfate nitrogen and Kjeldahl nitrogen concentrations (2,066 paired results) were significantly different from zero at the p = 0.05 level. Statistically, the means of Kjeldahl nitrogen concentrations were greater than those of nitrate-corrected alkaline persulfate nitrogen concentrations. Experimental evidence strongly

  18. Comparison of grass haylage digestibility and metabolic plasma profile in Icelandic and Standardbred horses.

    Science.gov (United States)

    Ragnarsson, S; Jansson, A

    2011-06-01

    The aim of the present study was to compare digestibility and metabolic response in Icelandic and Standardbred horses fed two grass haylages harvested at different stages of maturity. Six horses of each breed were used in a 24-day change-over design. A total collection of faeces was made on days 15-17 and 22-24. Blood samples were collected on day 24 of each period and analysed for total plasma protein (TPP), plasma urea, non-esterified fatty acids, cortisol and insulin concentration. There were no differences in digestibility coefficients of crude protein, neutral detergent fibre or energy between breeds but organic matter digestibility was higher in the Standardbred horses. On both haylages, the Icelandic horses gained weight whereas the Standardbred horses lost weight. The Icelandic horses had higher TPP, plasma insulin and lower plasma urea concentrations. Our results indicate that the Icelandic horse may be more prone to maintain positive energy balance in relation to the Standardbred horse, but there were no indication of a better digestive capacity in the Icelandic horses. © 2010 Blackwell Verlag GmbH.

  19. Simulating antler growth and energy, nitrogen, calcium and phosphorus metabolism in caribou

    Directory of Open Access Journals (Sweden)

    Ron Moen

    1998-03-01

    Full Text Available We added antler growth and mineral metabolism modules to a previously developed energetics model for ruminants to simulate energy and mineral balance of male and female caribou throughout an annual cycle. Body watet, fat, protein, and ash are monitored on a daily time step, and energy costs associated with reproduction and body mass changes are simulated. In order to simulate antler growth, we had to predict calcium and phosphorus metabolism as it is affected by antler growth, gestation, and lactation. We used data on dietary digestibility, protein, calcium and phosphorus content, and seasonal patterns in body mass to predict the energy, nitrogen, calcium, and phosphorus balances of a "generic" male and female caribou. Antler growth in males increased energy requirements during antler growth by 8 to 16%, depending on the efficiency with which energy was used for antler growth. Female energy requirements for antler growth were proportionately much smaller because of the smaller size of female antlers. Protein requirements for antler growth in both males and females were met by forage intake. Calcium and phosphorus must be resorbed from bone during peak antler growth in males, when > 25 g/day of calcium and > 12 g/day of phosphorus are being deposited in antlers. Females are capable of meeting calcium needs during antler growth without bone resorption, but phosphorus was resorbed from bone during the final stages of antler mineralization. After energy, phosphorus was most likely to limit growth of antlers for both males and females in our simulations. Input parameters can be easily changed to represent caribou from specific geographic regions in which dietary nutrient content or body mass patterns differ from those in our "generic" caribou. The model can be used to quantitatively analyze the evolutionary basis for development of antlers in female caribou, and the relationship between body mass and antler size in the Cervidae.

  20. INTAKE, DIGESTIBILITY, RUMEN METABOLISM AND GROWTH PERFORMANCE OF GOAT KIDS RAISED UNDER DIFFERENT PRODUCTION SYSTEMS

    Directory of Open Access Journals (Sweden)

    Sandra G. Solaiman

    2009-06-01

    Full Text Available Forty-five wether goat kids (BW of 21.76 + 0.76 were randomly assigned to one of three production systems for 14 weeks to evaluate intake, digestibility and goat performance. Production systems were: 1 feedlot (FL, housed in individual pens and fed 40% protein pellets, 40% soybean hulls and 20% bermudagrass hay; 2 grazing continuously on 1 hectare bahiagrass pasture (BP supplemented daily with 150 g of protein pellets/hd; and 3 browsing rotationally on 4, 0.5 hectare mimosa (MB supplemented daily with 100 g cracked corn/hd. Body weights were recorded every two weeks. Feed intake and digestibility were measured on eight goats from each treatment groups. Goats were fitted with canvas fecal collection bags, allowed for 3 days of adjustments followed by 5 days of fecal collection. Feces, feed offered, pasture and browse samples were analyzed for acid insoluble ash to determine digestibility and predict intake. Rumen fluid and blood samples were collected to measure volatile fatty acids and blood urea nitrogen (BUN. Total feed and medication costs also were recorded. Goats on FL system gained faster (P 0.10 in butyrate and valerate. However, acetate: propionate was lower (P 0.10 BUN. Numerically, browse system was most cost effective and bahaigrass pasture was most expensive in terms of animal production.

  1. Niche differentiation in nitrogen metabolism among methanotrophs within an operational taxonomic unit.

    Science.gov (United States)

    Hoefman, Sven; van der Ha, David; Boon, Nico; Vandamme, Peter; De Vos, Paul; Heylen, Kim

    2014-04-04

    The currently accepted thesis on nitrogenous fertilizer additions on methane oxidation activity assumes niche partitioning among methanotrophic species, with activity responses to changes in nitrogen content being dependent on the in situ methanotrophic community structure Unfortunately, widely applied tools for microbial community assessment only have a limited phylogenetic resolution mostly restricted to genus level diversity, and not to species level as often mistakenly assumed. As a consequence, intragenus or intraspecies metabolic versatility in nitrogen metabolism was never evaluated nor considered among methanotrophic bacteria as a source of differential responses of methane oxidation to nitrogen amendments. We demonstrated that fourteen genotypically different Methylomonas strains, thus distinct below the level at which most techniques assign operational taxonomic units (OTU), show a versatile physiology in their nitrogen metabolism. Differential responses, even among strains with identical 16S rRNA or pmoA gene sequences, were observed for production of nitrite and nitrous oxide from nitrate or ammonium, nitrogen fixation and tolerance to high levels of ammonium, nitrate, and hydroxylamine. Overall, reduction of nitrate to nitrite, nitrogen fixation, higher tolerance to ammonium than nitrate and tolerance and assimilation of nitrite were general features. Differential responses among closely related methanotrophic strains to overcome inhibition and toxicity from high nitrogen loads and assimilation of various nitrogen sources yield competitive fitness advantages to individual methane-oxidizing bacteria. Our observations proved that community structure at the deepest phylogenetic resolution potentially influences in situ functioning.

  2. Nitrogen and energy metabolism of sows during several reproductive cycles in relation to nitrogen intake

    NARCIS (Netherlands)

    Everts, H.

    1994-01-01

    By feeding the same diet during pregnancy and lactation sows are fed above the nitrogen requirement during pregnancy due to the relatively high nitrogen requirement during lactation. For feeding closer to the requirements at least two diets are needed: one diet with a low nitrogen content

  3. Comparison of different liquid anaerobic digestion effluents as inocula and nitrogen sources for solid-state batch anaerobic digestion of corn stover

    International Nuclear Information System (INIS)

    Xu Fuqing; Shi Jian; Lv Wen; Yu Zhongtang; Li Yebo

    2013-01-01

    Highlights: ► Compared methane production of solid AD inoculated with different effluents. ► Food waste effluent (FWE) had the largest population of acetoclastic methanogens. ► Solid AD inoculated with FWE produced the highest methane yield at F/E ratio of 4. ► Dairy waste effluent (DWE) was rich of cellulolytic and xylanolytic bacteria. ► Solid AD inoculated with DWE produced the highest methane yield at F/E ratio of 2. - Abstract: Effluents from three liquid anaerobic digesters, fed with municipal sewage sludge, food waste, or dairy waste, were evaluated as inocula and nitrogen sources for solid-state batch anaerobic digestion of corn stover in mesophilic reactors. Three feedstock-to-effluent (F/E) ratios (i.e., 2, 4, and 6) were tested for each effluent. At an F/E ratio of 2, the reactor inoculated by dairy waste effluent achieved the highest methane yield of 238.5 L/kgVS feed , while at an F/E ratio of 4, the reactor inoculated by food waste effluent achieved the highest methane yield of 199.6 L/kgVS feed . The microbial population and chemical composition of the three effluents were substantially different. Food waste effluent had the largest population of acetoclastic methanogens, while dairy waste effluent had the largest populations of cellulolytic and xylanolytic bacteria. Dairy waste also had the highest C/N ratio of 8.5 and the highest alkalinity of 19.3 g CaCO 3 /kg. The performance of solid-state batch anaerobic digestion reactors was closely related to the microbial status in the liquid anaerobic digestion effluents.

  4. Comparison of different liquid anaerobic digestion effluents as inocula and nitrogen sources for solid-state batch anaerobic digestion of corn stover

    Energy Technology Data Exchange (ETDEWEB)

    Xu Fuqing; Shi Jian [Department of Food, Agricultural and Biological Engineering, Ohio State University, Ohio Agricultural Research and Development Center, 1680 Madison Ave., Wooster, OH 44691 (United States); Lv Wen; Yu Zhongtang [Department of Animal Sciences, Ohio State University, Columbus, OH 43210 (United States); Li Yebo, E-mail: li.851@osu.edu [Department of Food, Agricultural and Biological Engineering, Ohio State University, Ohio Agricultural Research and Development Center, 1680 Madison Ave., Wooster, OH 44691 (United States)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Compared methane production of solid AD inoculated with different effluents. Black-Right-Pointing-Pointer Food waste effluent (FWE) had the largest population of acetoclastic methanogens. Black-Right-Pointing-Pointer Solid AD inoculated with FWE produced the highest methane yield at F/E ratio of 4. Black-Right-Pointing-Pointer Dairy waste effluent (DWE) was rich of cellulolytic and xylanolytic bacteria. Black-Right-Pointing-Pointer Solid AD inoculated with DWE produced the highest methane yield at F/E ratio of 2. - Abstract: Effluents from three liquid anaerobic digesters, fed with municipal sewage sludge, food waste, or dairy waste, were evaluated as inocula and nitrogen sources for solid-state batch anaerobic digestion of corn stover in mesophilic reactors. Three feedstock-to-effluent (F/E) ratios (i.e., 2, 4, and 6) were tested for each effluent. At an F/E ratio of 2, the reactor inoculated by dairy waste effluent achieved the highest methane yield of 238.5 L/kgVS{sub feed}, while at an F/E ratio of 4, the reactor inoculated by food waste effluent achieved the highest methane yield of 199.6 L/kgVS{sub feed}. The microbial population and chemical composition of the three effluents were substantially different. Food waste effluent had the largest population of acetoclastic methanogens, while dairy waste effluent had the largest populations of cellulolytic and xylanolytic bacteria. Dairy waste also had the highest C/N ratio of 8.5 and the highest alkalinity of 19.3 g CaCO{sub 3}/kg. The performance of solid-state batch anaerobic digestion reactors was closely related to the microbial status in the liquid anaerobic digestion effluents.

  5. NITROGEN CONTENT AND DRY-MATTER DIGESTIBILITY OF GUINEA AND SABI GRASSES AS INFLUENCED BY TREE LEGUME CANOPY

    Directory of Open Access Journals (Sweden)

    Andi Lagaligo Amar

    2012-08-01

    Full Text Available A research study was undertaken to study the grass layer across a mini landscape dominated by tree legume Albizia lebbeck to explore the nutritional differences of two introduced grasses, guinea grass (Panicum maximum and sabi grass (Urochloa mosambicensis, paying particular attention to the presence or absence of tree legume canopy of Albizia lebbeck. The two grass species showed a tendency to replace the native spear grass (Heteropogon contortus; their dominance was more or less complete under tree canopies but was increasing in open areas between trees. Nutritional differences were examined by nitrogen concentration and dry matter digestibility. For comparison, Heteropogon contortus, a native species only found in the open, was included in the nutritional determination using the same methods as the guinea and sabi grasses. The quality parameters of the pasture species were statistically compared (LSD, P=0.05. The quality of herbage was different between the species. Urochloa mosambicensis was better than Panicum maximum. In the open, sabi grass has higher N content (0.62% than guinea grass (0.55%, but they were similar when grown under the canopy (0.69% and 0.72%, respectively. Sabi grass has consistently higher dry matter digestibility (41.39% and 36.83%, respectively under the canopy and in the open, than guinea grass (27.78% and 24.77%. These two species are much higher in both N concentration and dry matter digestibility than the native spear grass. The native species has contained 0.28% N, and 17.65% digestible dry matter. The feeding values of herbage were influenced by the canopy factor. Both guinea and sabi grasses have better quality when grown under the tree canopies than in between canopies. Nitrogen concentration and dry matter digestibility of the guinea grass under canopy were, 0.72% and 27.78%, respectively, significantly higher than those from the open area, 0.55% and 24.77%. Similarly, herbage of sabi grass under canopy has 0

  6. Quantitative Metaproteomics Highlight the Metabolic Contributions of Uncultured Phylotypes in a Thermophilic Anaerobic Digester.

    Science.gov (United States)

    Hagen, Live H; Frank, Jeremy A; Zamanzadeh, Mirzaman; Eijsink, Vincent G H; Pope, Phillip B; Horn, Svein J; Arntzen, Magnus Ø

    2017-01-15

    In this study, we used multiple meta-omic approaches to characterize the microbial community and the active metabolic pathways of a stable industrial biogas reactor with food waste as the dominant feedstock, operating at thermophilic temperatures (60°C) and elevated levels of free ammonia (367 mg/liter NH 3 -N). The microbial community was strongly dominated (76% of all 16S rRNA amplicon sequences) by populations closely related to the proteolytic bacterium Coprothermobacter proteolyticus. Multiple Coprothermobacter-affiliated strains were detected, introducing an additional level of complexity seldom explored in biogas studies. Genome reconstructions provided metabolic insight into the microbes that performed biomass deconstruction and fermentation, including the deeply branching phyla Dictyoglomi and Planctomycetes and the candidate phylum "Atribacteria" These biomass degraders were complemented by a synergistic network of microorganisms that convert key fermentation intermediates (fatty acids) via syntrophic interactions with hydrogenotrophic methanogens to ultimately produce methane. Interpretation of the proteomics data also suggested activity of a Methanosaeta phylotype acclimatized to high ammonia levels. In particular, we report multiple novel phylotypes proposed as syntrophic acetate oxidizers, which also exert expression of enzymes needed for both the Wood-Ljungdahl pathway and β-oxidation of fatty acids to acetyl coenzyme A. Such an arrangement differs from known syntrophic oxidizing bacteria and presents an interesting hypothesis for future studies. Collectively, these findings provide increased insight into active metabolic roles of uncultured phylotypes and presents new synergistic relationships, both of which may contribute to the stability of the biogas reactor. Biogas production through anaerobic digestion of organic waste provides an attractive source of renewable energy and a sustainable waste management strategy. A comprehensive understanding

  7. Effect of feeding tamarind kernel powder extract residue on digestibility, nitrogen availability and ruminal fermentation in wethers.

    Science.gov (United States)

    Wang, Lin; Nakanishi, Takashi; Sato, Yoshiaki; Oishi, Kazato; Hirooka, Hiroyuki; Takahashi, Kei; Kumagai, Hajime

    2017-03-01

    This study was to examine in vivo digestibility, nitrogen balance and ruminal fermentation of tamarind ( Tamarind indica ) kernel powder extract residue (TKPER) compared to soybean products and by-products in wethers. Four wethers with initial body weight (BW) of 51.6±5.5 kg were assigned in a 4×4 Latin square design to investigate nutritional characteristics of TKPER, dry heat soybean (SB), dry soybean curd residue (SBCR) and soybean meal (SBM) feeding with ryegrass straw (R) at a ratio of 1:1 at 2% of BW in dry matter (DM) on a daily basis. The digestibility of DM, crude protein, and ether extract (EE) of TKPER-R diet were 57.0%, 87.0%, and 86.0%, respectively. Higher non-fiber carbohydrates digestibility was observed in TKPER-R diet (83.2%) than in SB-R diet (73.9%, pruminal ammonia nitrogen (NH 3 -N) contents at 4 h after feeding than those fed the SBM-R diet (pcontent, as well as lower acetate to propionate ratio (C2:C3) in rumen fluid than SBM feeding at 4 h after feeding (pruminants.

  8. [Research advance in nitrogen metabolism of plant and its environmental regulation].

    Science.gov (United States)

    Xu, Zhenzhu; Zhou, Guangsheng

    2004-03-01

    Nitrogen metabolism is not only one of the basic processes of plant physiology, but also one of the important parts of global chemical cycle. Plant nitrogen assimilation directly takes part in the synthesis and conversion of amino acid through the reduction of nitrate. During this stage, some key enzymes, e.g., nitrate reductase (NR), glutamine synthetase (GS), glutamate dehydrogenase (GDH), glutamine synthase (GOGAT), aspargine synthetase (AS), and asparate aminotransferase (AspAT) participate these processes. The protein is assimilated in plant cell through amino acid, and becomes a part of plant organism through modifying, classifying, transporting and storing processes, etc. The nitrogen metabolism is associated with carbonic metabolism through key enzyme regulations and the conversion of products, which consists of basic life process. Among these amino acids in plant cell, glutamic acid (Glu), glutamine (Gln), aspartic acid (Asp) and asparagines (Asn), etc., play a key role, which regulates their conversion each other and their contents in the plant cell through regulating formation and activity of those key enzymes. Environmental factors also affect the conversion and recycle of the key amino acids through regulating gene expression of the key enzymes and their activities. Nitrate and light intensity positively regulate the gene transcription of NR, but ammonium ions and Glu, Gln do the negative way. Water deficit is a very serious constraint on N2 fixation rate and soybean (Glycine max Merr.) grain yield, in which, ureide accumulation and degradation under water deficit appear to be the key issues of feedback mechanism on nitrogen fixation. Water stress decreases NR activity, but increases proteinase activity, and thus, they regulate plant nitrogen metabolism, although there are some different effects among species and cultivars. Water stress also decreases plant tissue protein content, ratio of protein and amino acid, and reduces the absorption of amino

  9. Voluntary intake, digestibility and nitrogen utilization by sheep fed ensiled grass clover mixture harvested at three stages of maturity

    Directory of Open Access Journals (Sweden)

    Marina Vranić

    2008-12-01

    Full Text Available The objective of this experiment was to study the effects of grass maturity at harvest on silage ad libitum intake, in vivo digestibility and N retention in wether sheep. The sward was harvested at the stem elongation, tasseling and flowering growth stages of orchardgrass (Dactylis glomerata. Three silages were offered to four Charolais wether sheep in an incomplete change over design with four periods. As the crop matured, there was an increase (P<0.001 in dry matter (DM, organic matter (OM and acid detergent fiber (ADF concentration and a decrease in crude protein (CP concentration (P<0.001. Increasing maturity of grass ensiled showed a linear decrease (P<0.01 in voluntary silage intake of DM, OM, neutral detergent fiber (NDF, a linear decrease (P<0.01 in digestibility of silage DM, OM, NDF, ADF, CP, and a linear decrease in nitrogen balance (P<0.01. No quadratic response was recorded in silage intake, digestibility or N balance. The results suggest that grass maturity at harvest influences the nutritive value of grass silage, in terms of ad libitum intake, in vivo digestibility and N retention in sheep, as a result of changes in chemical composition.

  10. Effects of lactone, ketone, and phenolic compounds on methane production and metabolic intermediates during anaerobic digestion.

    Science.gov (United States)

    Wikandari, Rachma; Sari, Noor Kartika; A'yun, Qurrotul; Millati, Ria; Cahyanto, Muhammad Nur; Niklasson, Claes; Taherzadeh, Mohammad J

    2015-02-01

    Fruit waste is a potential feedstock for biogas production. However, the presence of fruit flavors that have antimicrobial activity is a challenge for biogas production. Lactones, ketones, and phenolic compounds are among the several groups of fruit flavors that are present in many fruits. This work aimed to investigate the effects of two lactones, i.e., γ-hexalactone and γ-decalactone; two ketones, i.e., furaneol and mesifurane; and two phenolic compounds, i.e., quercetin and epicatechin on anaerobic digestion with a focus on methane production, biogas composition, and metabolic intermediates. Anaerobic digestion was performed in a batch glass digester incubated at 55 °C for 30 days. The flavor compounds were added at concentrations of 0.05, 0.5, and 5 g/L. The results show that the addition of γ-decalactone, quercetin, and epicathechin in the range of 0.5-5 g/L reduced the methane production by 50 % (MIC50). Methane content was reduced by 90 % with the addition of 5 g/L of γ-decalactone, quercetin, and epicathechin. Accumulation of acetic acid, together with an increase in carbon dioxide production, was observed. On the contrary, γ-hexalactone, furaneol, and mesifurane increased the methane production by 83-132 % at a concentration of 5 g/L.

  11. Nitrogen metabolism in a grapevine in vitro system

    Directory of Open Access Journals (Sweden)

    Nuria Llorens

    2002-09-01

    Full Text Available Ammonium, nitrate, nitrite, protein and individual and total amino acid contents were determined in grapevine (cv Sauvignon cultured in vitro. The enzyme activities of nitrate and nitrite reductases, glutamine synthetase, glutamate synthetase and dehydrogenase were also determined. The nitrogen taken up by the plants was 70% of the total nitrogen in the medium after 75 days of in vitro culture. Most of the nitrogen taken up was recovered in the leaves, yet only ammonia and amino acid concentrations were significantly higher in leaves. In roots, glutamine was the most abundant amino acid. In leaves, the most abundant amino acids were aspartate, glutamate, glutamine, alanine, arginine and g-aminobutirate. All enzyme activities were higher in roots than in leaves. These results suggest that both roots and leaves incorporate inorganic nitrogen into organic forms.

  12. Computational modeling to predict nitrogen balance during acute metabolic decompensation in patients with urea cycle disorders.

    Science.gov (United States)

    MacLeod, Erin L; Hall, Kevin D; McGuire, Peter J

    2016-01-01

    Nutritional management of acute metabolic decompensation in amino acid inborn errors of metabolism (AA IEM) aims to restore nitrogen balance. While nutritional recommendations have been published, they have never been rigorously evaluated. Furthermore, despite these recommendations, there is a wide variation in the nutritional strategies employed amongst providers, particularly regarding the inclusion of parenteral lipids for protein-free caloric support. Since randomized clinical trials during acute metabolic decompensation are difficult and potentially dangerous, mathematical modeling of metabolism can serve as a surrogate for the preclinical evaluation of nutritional interventions aimed at restoring nitrogen balance during acute decompensation in AA IEM. A validated computational model of human macronutrient metabolism was adapted to predict nitrogen balance in response to various nutritional interventions in a simulated patient with a urea cycle disorder (UCD) during acute metabolic decompensation due to dietary non-adherence or infection. The nutritional interventions were constructed from published recommendations as well as clinical anecdotes. Overall, dextrose alone (DEX) was predicted to be better at restoring nitrogen balance and limiting nitrogen excretion during dietary non-adherence and infection scenarios, suggesting that the published recommended nutritional strategy involving dextrose and parenteral lipids (ISO) may be suboptimal. The implications for patients with AA IEM are that the medical course during acute metabolic decompensation may be influenced by the choice of protein-free caloric support. These results are also applicable to intensive care patients undergoing catabolism (postoperative phase or sepsis), where parenteral nutritional support aimed at restoring nitrogen balance may be more tailored regarding metabolic fuel selection.

  13. Effect of ammoniacal nitrogen on one-stage and two-stage anaerobic digestion of food waste

    Energy Technology Data Exchange (ETDEWEB)

    Ariunbaatar, Javkhlan, E-mail: jaka@unicas.it [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio 43, 03043 Cassino, FR (Italy); UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft (Netherlands); Scotto Di Perta, Ester [Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio 21, 80125 Naples (Italy); Panico, Antonio [Telematic University PEGASO, Piazza Trieste e Trento, 48, 80132 Naples (Italy); Frunzo, Luigi [Department of Mathematics and Applications Renato Caccioppoli, University of Naples Federico II, Via Claudio, 21, 80125 Naples (Italy); Esposito, Giovanni [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Via Di Biasio 43, 03043 Cassino, FR (Italy); Lens, Piet N.L. [UNESCO-IHE Institute for Water Education, Westvest 7, 2611 AX Delft (Netherlands); Pirozzi, Francesco [Department of Civil, Architectural and Environmental Engineering, University of Naples Federico II, Via Claudio 21, 80125 Naples (Italy)

    2015-04-15

    Highlights: • Almost 100% of the biomethane potential of food waste was recovered during AD in a two-stage CSTR. • Recirculation of the liquid fraction of the digestate provided the necessary buffer in the AD reactors. • A higher OLR (0.9 gVS/L·d) led to higher accumulation of TAN, which caused more toxicity. • A two-stage reactor is more sensitive to elevated concentrations of ammonia. • The IC{sub 50} of TAN for the AD of food waste amounts to 3.8 g/L. - Abstract: This research compares the operation of one-stage and two-stage anaerobic continuously stirred tank reactor (CSTR) systems fed semi-continuously with food waste. The main purpose was to investigate the effects of ammoniacal nitrogen on the anaerobic digestion process. The two-stage system gave more reliable operation compared to one-stage due to: (i) a better pH self-adjusting capacity; (ii) a higher resistance to organic loading shocks; and (iii) a higher conversion rate of organic substrate to biomethane. Also a small amount of biohydrogen was detected from the first stage of the two-stage reactor making this system attractive for biohythane production. As the digestate contains ammoniacal nitrogen, re-circulating it provided the necessary alkalinity in the systems, thus preventing an eventual failure by volatile fatty acids (VFA) accumulation. However, re-circulation also resulted in an ammonium accumulation, yielding a lower biomethane production. Based on the batch experimental results the 50% inhibitory concentration of total ammoniacal nitrogen on the methanogenic activities was calculated as 3.8 g/L, corresponding to 146 mg/L free ammonia for the inoculum used for this research. The two-stage system was affected by the inhibition more than the one-stage system, as it requires less alkalinity and the physically separated methanogens are more sensitive to inhibitory factors, such as ammonium and propionic acid.

  14. Effect of ammoniacal nitrogen on one-stage and two-stage anaerobic digestion of food waste

    International Nuclear Information System (INIS)

    Ariunbaatar, Javkhlan; Scotto Di Perta, Ester; Panico, Antonio; Frunzo, Luigi; Esposito, Giovanni; Lens, Piet N.L.; Pirozzi, Francesco

    2015-01-01

    Highlights: • Almost 100% of the biomethane potential of food waste was recovered during AD in a two-stage CSTR. • Recirculation of the liquid fraction of the digestate provided the necessary buffer in the AD reactors. • A higher OLR (0.9 gVS/L·d) led to higher accumulation of TAN, which caused more toxicity. • A two-stage reactor is more sensitive to elevated concentrations of ammonia. • The IC 50 of TAN for the AD of food waste amounts to 3.8 g/L. - Abstract: This research compares the operation of one-stage and two-stage anaerobic continuously stirred tank reactor (CSTR) systems fed semi-continuously with food waste. The main purpose was to investigate the effects of ammoniacal nitrogen on the anaerobic digestion process. The two-stage system gave more reliable operation compared to one-stage due to: (i) a better pH self-adjusting capacity; (ii) a higher resistance to organic loading shocks; and (iii) a higher conversion rate of organic substrate to biomethane. Also a small amount of biohydrogen was detected from the first stage of the two-stage reactor making this system attractive for biohythane production. As the digestate contains ammoniacal nitrogen, re-circulating it provided the necessary alkalinity in the systems, thus preventing an eventual failure by volatile fatty acids (VFA) accumulation. However, re-circulation also resulted in an ammonium accumulation, yielding a lower biomethane production. Based on the batch experimental results the 50% inhibitory concentration of total ammoniacal nitrogen on the methanogenic activities was calculated as 3.8 g/L, corresponding to 146 mg/L free ammonia for the inoculum used for this research. The two-stage system was affected by the inhibition more than the one-stage system, as it requires less alkalinity and the physically separated methanogens are more sensitive to inhibitory factors, such as ammonium and propionic acid

  15. Dietary structured lipids for post-weaning piglets: fat digestibility, nitrogen retention and fatty acid profiles of tissues

    DEFF Research Database (Denmark)

    Straarup, Ellen Marie; Danielsen, V.; Høy, Carl-Erik

    2006-01-01

    In four groups of post-weaning piglets the effects of triacylglycerol structure and fatty acid profiles of four dietary fats on apparent faecal nutrient digestibility, nitrogen retention and fatty acid profiles of platelet and erythrocyte membranes, liver, adipose tissue and skeletal muscle were...... examined. Dietary fats included as 10% (w/w) of the diets were two structured fats of rapeseed oil interesterified with tridecanoin (R1) or coconut oil (R2), respectively, one mixture of rapeseed oil and coconut oil (R3) and rapeseed oil as control (R4). Faeces and urine from piglets weaned at 28 days...

  16. Effects of Mg on C and N Metabolism of Soybean at Different Nitrogen Supplying Levels

    Institute of Scientific and Technical Information of China (English)

    LANG Man; LIU Yuanying; PENG Xianlong; ZHANG Wenzhao

    2006-01-01

    A pot experiment was conducted to study the effects of magnesium on carbon and nitrogen metabolism of soybean at different nitrogen supplying levels. The results showed that the effects of magnesium at low nitrogen rate on N content, soluble protein, soluble sugar contents were not alike at different growth stage, although nodule dry weights raised, the yield and protein content of seeds decreased, however, the oil content was improved.The application of magnesium at medium and high nitrogen supplying levels promoted the uptake of N effectively,increased the soluble protein and soluble sugar contents, but the nodule dry weights of application magnesium at medium nitrogen supplying level decreased and the yield increased only a little despite the improved quality.Application of magnesium at high nitrogen supplying level raised nodule dry weights and soybean yield significantly, the quality of seeds was also improved.

  17. Genome-centric resolution of microbial diversity, metabolism and interactions in anaerobic digestion.

    Science.gov (United States)

    Vanwonterghem, Inka; Jensen, Paul D; Rabaey, Korneel; Tyson, Gene W

    2016-09-01

    Our understanding of the complex interconnected processes performed by microbial communities is hindered by our inability to culture the vast majority of microorganisms. Metagenomics provides a way to bypass this cultivation bottleneck and recent advances in this field now allow us to recover a growing number of genomes representing previously uncultured populations from increasingly complex environments. In this study, a temporal genome-centric metagenomic analysis was performed of lab-scale anaerobic digesters that host complex microbial communities fulfilling a series of interlinked metabolic processes to enable the conversion of cellulose to methane. In total, 101 population genomes that were moderate to near-complete were recovered based primarily on differential coverage binning. These populations span 19 phyla, represent mostly novel species and expand the genomic coverage of several rare phyla. Classification into functional guilds based on their metabolic potential revealed metabolic networks with a high level of functional redundancy as well as niche specialization, and allowed us to identify potential roles such as hydrolytic specialists for several rare, uncultured populations. Genome-centric analyses of complex microbial communities across diverse environments provide the key to understanding the phylogenetic and metabolic diversity of these interactive communities. © 2016 Society for Applied Microbiology and John Wiley & Sons Ltd.

  18. Enhanced photosynthetic capacity increases nitrogen metabolism through the coordinated regulation of carbon and nitrogen assimilation in Arabidopsis thaliana.

    Science.gov (United States)

    Otori, Kumi; Tanabe, Noriaki; Maruyama, Toshiki; Sato, Shigeru; Yanagisawa, Shuichi; Tamoi, Masahiro; Shigeoka, Shigeru

    2017-09-01

    Plant growth and productivity depend on interactions between the metabolism of carbon and nitrogen. The sensing ability of internal carbon and nitrogen metabolites (the C/N balance) enables plants to regulate metabolism and development. In order to investigate the effects of an enhanced photosynthetic capacity on the metabolism of carbon and nitrogen in photosynthetically active tissus (source leaves), we herein generated transgenic Arabidopsis thaliana plants (ApFS) that expressed cyanobacterial fructose-1,6-/sedoheptulose-1,7-bisphosphatase in their chloroplasts. The phenotype of ApFS plants was indistinguishable from that of wild-type plants at the immature stage. However, as plants matured, the growth of ApFS plants was superior to that of wild-type plants. Starch levels were higher in ApFS plants than in wild-type plants at 2 and 5 weeks. Sucrose levels were also higher in ApFS plants than in wild-type plants, but only at 5 weeks. On the other hand, the contents of various free amino acids were lower in ApFS plants than in wild-type plants at 2 weeks, but were similar at 5 weeks. The total C/N ratio was the same in ApFS plants and wild-type plants, whereas nitrite levels increased in parallel with elevations in nitrate reductase activity at 5 weeks in ApFS plants. These results suggest that increases in the contents of photosynthetic intermediates at the early growth stage caused a temporary imbalance in the free-C/free-N ratio and, thus, the feedback inhibition of the expression of genes involved in the Calvin cycle and induction of the expression of those involved in nitrogen metabolism due to supply deficient free amino acids for maintenance of the C/N balance in source leaves of ApFS plants.

  19. The use of acid detergent insoluble nitrogen to predict digestibility of ...

    African Journals Online (AJOL)

    Animal Nutrition and Animal Products Institute, Private Bag. X2, lrene, 1675 ... predict digestibility of rumen undegradable protein (UDP-D) of heat processed ..... of soybean meal and sunflower seeds for dairy cattle in early lactation. J. Dairy ...

  20. Nitrogen metabolism of the eutrophic Delaware River ecosystem

    International Nuclear Information System (INIS)

    Anon.

    1986-01-01

    A comprehensive investigation of the nitrogen cycle in the Delaware River was carried out using 13 N tracers to measure rates for important transformations of nitrogen. Daily, depth-averaged 15 N rates for the principal inorganic nitrogen species were consistent with rates derived from longitudinal profiles of concentration in the river. The data indicated that nitrification was a rapid, irreversible sink for NH 4 + , with export of the product NO 3 - from the study area. Utilization of NO 3 - by primary producers was negligible, owing to low irradiance levels and to high NH 4 + concentrations. The oxygen sag near Philadelphia was found to result from oxygen demand in the water column, with only minor benthic influence. Reaeration provided the major oxygen input. Nitrification accounted for about 1% of the net oxygen demand near Philadelphia but as much as 25% farther downstream

  1. Differences in nitrogen and urea metabolism between goats bred for ...

    African Journals Online (AJOL)

    This experiment was conducted to determine whether selection for fleece weight is accompanied by changes in the efficiency of nitrogen utilization, using Angora and Boer goats as models of animals bred for fleece or meat production respectively. A diet, containing a protein: energy ratio of 12 g CP/ MJ ME, was fed at ...

  2. Comparative studies of the nitrogen metabolism of phytoplankton and periphyton in oligotrophic lakes

    International Nuclear Information System (INIS)

    Axler, R.P.; Goldman, C.R.; Reuter, J.E.; Loeb, S.L.; Priscu, J.C.; Carlton, R.G.

    1983-01-01

    This report presents the preliminary data of limnological research at the meso-oligotrophic Castle Lake, CA and at the ultratrophic Lake Tahoe, CA-NEV, USA, during 1980 to 1981. The areas of study were effects of nutrients enrichment and deficiency on primary producers; nitrogen cycling and nitrogen metabolism of benthic and planktonic algae and whole-epilimnion enrichment with ammonium nitrate. Tracer techniques using 14 C- and 15 N-labelled compounds were employed in the study

  3. Ostertagia ostertagi in calves: growth, nitrogen balance and digestibility studies conducted during winter feeding following different fenbendazole therapy programmes.

    Science.gov (United States)

    Parkins, J J; Bairden, K; Armour, J

    1982-01-01

    Observations of growth, nitrogen (N) balance and digestibility were made during the first winter housing period upon three groups of calves which had previously been naturally infected with Ostertagia ostertagi and which were left either untreated (A) or treated with fenbendazole on three occasions (B) or every two weeks during the entire grazing season (C). The diet given contained sufficient metabolisable energy but only about 60 per cent of the recommended crude protein to sustain a daily growth rate of 0.5 kg. Growth rates were only 50 per cent of that expected on a basis of metabolisable energy input with untreated calves A being poorest. Water intake and output was greatest in group A. There were no significant differences in digestibility between groups although group A had the lowest apparent crude protein digestibility. N balance was always lowest in group A and highest in group C but group B demonstrated a marked increase in N retention with time after housing. Differences in N retention were mainly accounted for by increased urinary N excretion. It is concluded that, under conditions of suboptimal protein intake, nematode infection in the growing calf can markedly affect production even after efficient anthelmintic treatment.

  4. Novel Metabolic Attributes of the Genus Cyanothece, Comprising a Group of Unicellular Nitrogen-Fixing Cyanobacteria

    Science.gov (United States)

    Bandyopadhyay, Anindita; Elvitigala, Thanura; Welsh, Eric; Stöckel, Jana; Liberton, Michelle; Min, Hongtao; Sherman, Louis A.; Pakrasi, Himadri B.

    2011-01-01

    ABSTRACT The genus Cyanothece comprises unicellular cyanobacteria that are morphologically diverse and ecologically versatile. Studies over the last decade have established members of this genus to be important components of the marine ecosystem, contributing significantly to the nitrogen and carbon cycle. System-level studies of Cyanothece sp. ATCC 51142, a prototypic member of this group, revealed many interesting metabolic attributes. To identify the metabolic traits that define this class of cyanobacteria, five additional Cyanothece strains were sequenced to completion. The presence of a large, contiguous nitrogenase gene cluster and the ability to carry out aerobic nitrogen fixation distinguish Cyanothece as a genus of unicellular, aerobic nitrogen-fixing cyanobacteria. Cyanothece cells can create an anoxic intracellular environment at night, allowing oxygen-sensitive processes to take place in these oxygenic organisms. Large carbohydrate reserves accumulate in the cells during the day, ensuring sufficient energy for the processes that require the anoxic phase of the cells. Our study indicates that this genus maintains a plastic genome, incorporating new metabolic capabilities while simultaneously retaining archaic metabolic traits, a unique combination which provides the flexibility to adapt to various ecological and environmental conditions. Rearrangement of the nitrogenase cluster in Cyanothece sp. strain 7425 and the concomitant loss of its aerobic nitrogen-fixing ability suggest that a similar mechanism might have been at play in cyanobacterial strains that eventually lost their nitrogen-fixing ability. PMID:21972240

  5. Effects of additive application upon ad libitum intake, in vivo digestibility and nitrogen balance of alfalfa haylage

    Directory of Open Access Journals (Sweden)

    Mladen Knežević

    2009-09-01

    Full Text Available The research objective was to determine the effect of the additive Sill-All application on ad libitum intake, in vivo digestibility and nitrogen balance of alfalfa haylage. About 40 % alfalfa plants was ensiled at the phonological flowering stage into plastic foil-wrapped bales without or with additive (2 L t-1 plant mass. No statistically significant differences were found between alfalfa ensiled without additive and alfalfa ensiled with additive for the content of dry matter (DM (632 g and 631 g DM kg-1 fresh sample, respectively. Alfalfa ensiled without additive contained 921 g organic matter (OM kg-1 DM, which was significantly higher (P<0.001 compared to alfalfa ensiled with additive (902 g OM kg-1 DM. Alfalfa ensiled without additive contained 141 g crude proteins (CP kg-1 DM, which was significantly higher (P<0.001 compared to alfalfa ensiled with additive (139 g CP kg-1 DM. Alfalfa ensiled with additive contained significantly less acid detergent fibers (ADF (P<0.001 compared to alfalfa ensiled without additive (445 g kg-1 DM and 456 g kg-1 DM, respectively and had a lower pH value (P<0.001 (5.29 and 5.56, respectively. No statistically significant differences were found between the studied feeding treatments for ad libitum intake of fresh ration and DM ration, for the measured parameters of digestibility and N balance. It was concluded that addition of the additive to alfalfa haylage led to significant changes in chemical composition; however, changes in chemical composition had no impact on measured biological parameters (ad libitum intake, in vivo digestibility and nitrogen balance.

  6. Effects of Added Lipids on Digestibility and Nitrogen Balance in Oiled Common Murres ( Uria aalge ) and Western Grebes ( Aechmophorus occidentalis ) Fed Four Formulations of a Critical Care Diet.

    Science.gov (United States)

    Duerr, Rebecca S; Klasing, Kirk C

    2017-06-01

    Nutritional support is a primary therapy administered to oiled animals during responses to oil spills, but data informing nutritional decision-making during events are limited. In this study, 44 common murres ( Uria aalge ) and 6 Western grebes ( Aechmophorus occidentalis ), naturally oiled by oceanic seeps off the coast of Ventura and Santa Barbara Counties, CA, USA, were assigned to 1 of 4 groups fed diets with varying levels (6.8% [no added oil], 11%, and 20%) and types (salmon, corn) of oil added to a partially purified basal diet. Birds used in the study ranged from extremely emaciated to thin body condition (62%-80% wild bird mean body mass). Acid-insoluble ash was used as an indigestible dietary marker to quantify nitrogen retention, apparent nitrogen digestibility, nitrogen-corrected apparent metabolizable energy, energy digestibility, fat retention, fat digestibility, and estimated fat excretion. Fat excretion is important in these species because once birds have been cleaned they are at risk of plumage recontamination from excreted fat during care. Lower fat diets resulted in lower fat excretion but higher nitrogen retention, higher apparent nitrogen digestibility, and higher apparent metabolizable energy. Decreases in nitrogen retention were significantly related to increases in fat excretion. Regardless of diet, energy digestibility significantly declined with declines in body mass, suggesting severity of emaciation reduced a birds' ability to extract energy from food. Energy digestibility was highest in the 11% (low) salmon oil diet; hence, this diet had the highest effective energy content despite a lower gross kcal/kg diet. Diets fed during oil spills historically have had high fat concentrations to provide maximum caloric support. Results of this study suggest that lower fat diets may be more efficacious for nutritionally depleted seabirds. This study provides valuable data to guide clinical decision making regarding nutritional support during oil

  7. Effects of Dietary Electrolyte Balance on Growth Performance, Nitrogen Metabolism and Some Blood Biochemical Parameters of Growing Rabbits

    Directory of Open Access Journals (Sweden)

    J. W. Li

    2013-12-01

    Full Text Available The effects of different dietary electrolyte balance (DEB on growth performance, nitrogen (N metabolism and some blood biochemical parameters were investigated in 2 to 3 months old growing rabbits. A total of 150 growing rabbits of 2 months age were randomly divided into five groups according to average body weight, with 30 rabbits in each group. The DEB levels of the five experimental diets were −154, −3.16, +201, +347, and +500 meq/kg of dry matter (DM, respectively. There was a 7-d adaptation period and a 23-d experimental period. The results showed that the DEB levels had a quadratic affect on the average daily feed intake (ADFI (p<0.001. The greatest ADFI was achieved when the DEB level was +201 meq/kg DM. Fecal N (FN content linearly decreased (0.047, while digestible N (DN, retained N (RN, efficiency of intake N converted into digestible N (DN/IN and the efficiency of intake N converted into retained N (RN/IN linearly increased with the DEB increase (0.020, 0.004, 0.021, and 0.049, respectively. Serum phosphorus (P ion content linearly increased with the DEB increase (p = 0.036. The DEB had a quadratic relationship with serum anion gap (AG (p = 0.002 and serum parathyroid hormone (PTH content (p = 0.016. The DEB levels quadratically affected base excess (BE in the plasma (p<0.001. In conclusion, the DEB unaffected growth performance but affected feed intake, N metabolism and some blood biochemical parameters of growing rabbits.

  8. Carbon and nitrogen metabolism in arbuscular mycorrhizal maize plants under low-temperature stress

    DEFF Research Database (Denmark)

    Zhu, Xian-Can; Song, Feng-Bin; Liu, Fulai

    2015-01-01

    Effects of the arbuscular mycorrhizal (AM) fungus Glomus tortuosum on carbon (C) and nitrogen (N) metabolism of Zea mays L. grown under low-temperature stress was investigated. Maize plants inoculated or not inoculated with AM fungus were grown in a growth chamber at 258C for 4 weeks...... temperature regimes. AM symbiosis modulated C metabolic enzymes, thereby inducing an accumulation of soluble sugars, which may have contributed to an increased tolerance to low temperature, and therefore higher Pn in maize plants....

  9. Influence of Vitamin B Auxotrophy on Nitrogen Metabolism in Eukaryotic Phytoplankton

    Directory of Open Access Journals (Sweden)

    Erin M Bertrand

    2012-10-01

    Full Text Available While nitrogen availability is known to limit primary production in large parts of the ocean, vitamin starvation amongst eukaryotic phytoplankton is becoming increasingly recognized as an oceanographically relevant phenomenon. Cobalamin (B12 and thiamine (B1 auxotrophy are widespread throughout eukaryotic phytoplankton, with over 50% of cultured isolates requiring B12 and 20% requiring B1. The frequency of vitamin auxotrophy in harmful algal bloom species is even higher. Instances of colimitation between nitrogen and B vitamins have been observed in marine environments, and interactions between these nutrients have been shown to impact phytoplankton species composition. This review evaluates the potential for interactive effects of nitrogen and vitamin B12 and B1 starvation in eukaryotic phytoplankton. B12 plays essential roles in amino acid and one-carbon metabolism, while B1 is important for primary carbohydrate and amino acid metabolism and likely useful as an anti-oxidant. Here we will focus on three potential metabolic interconnections between vitamin, nitrogen and sulfur metabolism that may have ramifications for the role of vitamin and nitrogen scarcities in driving ocean productivity and species composition. These include: (1 B12, B1, and N starvation impacts on osmolyte and antioxidant production, (2 B12 and B1 starvation impacts on polyamine biosynthesis, and (3 influence of B12 and B1 starvation on the diatom urea cycle and amino acid recycling through impacts on the citric acid cycle. We evaluate evidence for these interconnections and identify oceanographic contexts in which each may impact rates of primary production and phytoplankton community composition. Major implications include that B12 and B1 deprivation may impair the ability of phytoplankton to recover from nitrogen starvation and that changes in vitamin and nitrogen availability may synergistically impact harmful algal bloom formation.

  10. A Natural Light/Dark Cycle Regulation of Carbon-Nitrogen Metabolism and Gene Expression in Rice Shoots.

    Science.gov (United States)

    Li, Haixing; Liang, Zhijun; Ding, Guangda; Shi, Lei; Xu, Fangsen; Cai, Hongmei

    2016-01-01

    Light and temperature are two particularly important environmental cues for plant survival. Carbon and nitrogen are two essential macronutrients required for plant growth and development, and cellular carbon and nitrogen metabolism must be tightly coordinated. In order to understand how the natural light/dark cycle regulates carbon and nitrogen metabolism in rice plants, we analyzed the photosynthesis, key carbon-nitrogen metabolites, and enzyme activities, and differentially expressed genes and miRNAs involved in the carbon and nitrogen metabolic pathway in rice shoots at the following times: 2:00, 6:00, 10:00, 14:00, 18:00, and 22:00. Our results indicated that more CO2 was fixed into carbohydrates by a high net photosynthetic rate, respiratory rate, and stomatal conductance in the daytime. Although high levels of the nitrate reductase activity, free ammonium and carbohydrates were exhibited in the daytime, the protein synthesis was not significantly facilitated by the light and temperature. In mRNA sequencing, the carbon and nitrogen metabolism-related differentially expressed genes were obtained, which could be divided into eight groups: photosynthesis, TCA cycle, sugar transport, sugar metabolism, nitrogen transport, nitrogen reduction, amino acid metabolism, and nitrogen regulation. Additionally, a total of 78,306 alternative splicing events have been identified, which primarily belong to alternative 5' donor sites, alternative 3' acceptor sites, intron retention, and exon skipping. In sRNA sequencing, four carbon and nitrogen metabolism-related miRNAs (osa-miR1440b, osa-miR2876-5p, osa-miR1877 and osa-miR5799) were determined to be regulated by natural light/dark cycle. The expression level analysis showed that the four carbon and nitrogen metabolism-related miRNAs negatively regulated their target genes. These results may provide a good strategy to study how natural light/dark cycle regulates carbon and nitrogen metabolism to ensure plant growth and

  11. Growth and nitrogen metabolism changes in NaCl-stressed tobacco ...

    African Journals Online (AJOL)

    Growth and nitrogen metabolism changes in NaCl-stressed tobacco (Nicotiana rustica L. var. Souffi) seedlings. Chokri Zaghdoud, Houda Maâroufi-Dguimi, Youssef Ouni, Mokhtar Guerfel, Houda Gouia, Kamel-Eddine Negaz, Ali Ferchichi, Mohamed Debouba ...

  12. Nitrogenous metabolism in Thoroughbred and Arabian foals from birth to five months of age

    OpenAIRE

    Piccione,G.; Costa,A.; Fazio,F.; Grasso,F.; Caola,G.

    2006-01-01

    The maturation of nitrogen metabolism was studied in six Thoroughbred and six Arabian foals. Rectal temperature, heart and respiratory rates and serum concentration of several hematochemical parameters (total protein, urea, uric acid, creatinine, and albumine) were monitored from birth to 5 months of age. In both breeds, all the parameters except albumine showed significant differences over time (P

  13. Passage and absorption of dietary and endogenous nitrogen in different regions of the digestive tract of rats given a single meal of 15N-labelled barley

    International Nuclear Information System (INIS)

    Partridge, I.G.; Simon, O.; Bergner, H.

    1985-01-01

    Young male Wistar rats (86.9 +- 0.96 g) were fasted for 24 hours and then offered a single meal (intake of 1 to 2.5 g) of 15 N-labelled barley (5.34 atom% 15 N excess). The test meal also contained Cr 2 O 3 (20 mg/g). Groups of five animals were killed 0.5; 1; 1.5; 2; 2.5; 4; 6 and 8 hours after removal of food. The contents of different regions of the digestive tract (stomach, proximal, middle and distal third of small intestine, large intestine) and feces were analyzed for Cr 2 O 3 and for N and 15 N abundance in both a TCA soluble and a TCA precipitable fraction. The distribution patterns of Cr 2 O 3 and 15 N along the digestive tract were very similar. If the disappearance of 15 N from the contents of the small and of the large intestines was expressed as a proportion of the gastric outflow of 15 N, a disappearance rate of 90% was found. On the basis of isotopic dilution the proportion of dietary nitrogen in digesta was calculated. The results illustrated the intensive dilution of dietary nitrogen by endogenous secretions in all regions of the digestive tract. In the distal small intestine endogenous nitrogen accounted for 70% of total nitrogen. 17 mg endogenous N were produced by the stomach within 8 hours after the single meal. The results show the value of the method in determining the true digestibility of nitrogen in 15 N-labelled feedstuffs more accurately than with classical methods and in providing an insight into the dynamics of nitrogen absorption and secretion in the digestive tract. (author)

  14. GlnR-mediated regulation of nitrogen metabolism in the actinomycete Saccharopolyspora erythraea.

    Science.gov (United States)

    Yao, Li-Li; Liao, Cheng-Heng; Huang, Gang; Zhou, Ying; Rigali, Sebastien; Zhang, Buchang; Ye, Bang-Ce

    2014-09-01

    Nitrogen source sensing, uptake, and assimilation are central for growth and development of microorganisms which requires the participation of a global control of nitrogen metabolism-associated genes at the transcriptional level. In soil-dwelling antibiotic-producing actinomycetes, this role is played by GlnR, an OmpR family regulator. In this work, we demonstrate that SACE_7101 is the ortholog of actinomycetes' GlnR global regulators in the erythromycin producer Saccharopolyspora erythraea. Indeed, the chromosomal deletion of SACE_7101 severely affects the viability of S. erythraea when inoculated in minimal media supplemented with NaNO3, NaNO2, NH4Cl, glutamine, or glutamate as sole nitrogen source. Combination of in silico prediction of cis-acting elements, subsequent in vitro (through gel shift assays) and in vivo (real-time reverse transcription polymerase chain reaction) validations of the predicted target genes revealed a very large GlnR regulon aimed at adapting the nitrogen metabolism of S. erythraea. Indeed, enzymes/proteins involved in (i) uptake and assimilation of ammonium, (ii) transport and utilization of urea, (iii) nitrite/nitrate, (iv) glutamate/glutamine, (v) arginine metabolism, (vi) nitric oxide biosynthesis, and (vii) signal transduction associated with the nitrogen source supplied have at least one paralog gene which expression is controlled by GlnR. Our work highlights a GlnR-binding site consensus sequence (t/gna/cAC-n6-GaAAc) which is similar although not identical to the consensus sequences proposed for other actinomycetes. Finally, we discuss the distinct and common features of the GlnR-mediated transcriptional control of nitrogen metabolism between S. erythraea and the model organism Streptomyces coelicolor.

  15. [Influence of an elevation of the temperature of water on the digestibility of dry matter, nitrogen and energy of food distributed to the rainbow trout (Salmo gairdneri Rich)].

    Science.gov (United States)

    Choubert, G; Fauconneau, B; Luquet, P

    1982-01-01

    Rainbow trout adapted to a water temperature of 10 degrees C were subjected to an abrupt rise in temperature (from 10 to 18 degrees C) in a 24-h period. Fish maintained in recirculated water were fed to satiation twice a day and their feed intakes were recorded. Changes in dry matter, nitrogen and energy digestibility were measured each day at 10 degrees C and during the course of acclimatation to 18 degrees C. Low water temperature (10 degrees C) was characterized by a feed intake of 1.84 g (DM)/fish/day; digestibility values were as follows: dry matter 62.15 p. 100, nitrogen 86.91 p. 100, energy 70.60 p. 100. High water temperature (18 degrees C) was characterized by a feed intake of 3.75 g (DM)/fish/day; digestibility values were as follows: dry matter 66.08 p. 100, nitrogen 89.57 p. 100, energy 73.52 p. 100. The daily patterns in digestibility were affected by the rise in temperature. The digestibility values were stabilized by day 7 after the positive thermal shock.

  16. Deletion of Type I glutamine synthetase deregulates nitrogen metabolism and increases ethanol production in Clostridium thermocellum

    Energy Technology Data Exchange (ETDEWEB)

    Rydzak, Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Garcia, David [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Stevenson, David M. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Bacteriology; Sladek, Margaret [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Klingeman, Dawn M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Holwerda, Evert K. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division; Dartmouth College, Hanover, NH (United States). Thayer School of Engineering; Amador-Noguez, Daniel [Univ. of Wisconsin, Madison, WI (United States). Dept. of Bacteriology; Brown, Steven D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center; Guss, Adam M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Biosciences Division, BioEnergy Science Center

    2017-05-01

    Clostridium thermocellum rapidly deconstructs cellulose and ferments resulting hydrolysis products into ethanol and other products, and is thus a promising platform organism for the development of cellulosic biofuel production via consolidated bioprocessing. And while recent metabolic engineering strategies have targeted eliminating canonical fermentation products (acetate, lactate, formate, and H2), C. thermocellum also secretes amino acids, which has limited ethanol yields in engineered strains to approximately 70% of the theoretical maximum. To decrease amino acid secretion, we attempted to reduce ammonium assimilation by deleting the Type I glutamine synthetase (glnA) in C. thermocellum. Deletion of glnA reduced levels of secreted valine and total amino acids by 53% and 44% respectively, and increased ethanol yields by 53%. RNA-seq analysis revealed that genes encoding the RNF-complex were more highly expressed in ΔglnA and may have a role in improving NADH-availability for ethanol production. While a significant up-regulation of genes involved in nitrogen assimilation and urea uptake suggested that deletion of glnA induces a nitrogen starvation response, metabolomic analysis showed an increase in intracellular glutamine and α-ketoglutarate levels indicative of nitrogen-rich conditions. Here, we propose that deletion of glnA causes deregulation of nitrogen metabolism, leading to overexpression of nitrogen metabolism genes and, in turn, elevated glutamine/α-ketoglutarate levels. Here we demonstrate that perturbation of nitrogen assimilation is a promising strategy to redirect flux from the production of nitrogenous compounds toward biofuels in C. thermocellum.

  17. Deletion of Type I glutamine synthetase deregulates nitrogen metabolism and increases ethanol production in Clostridium thermocellum.

    Science.gov (United States)

    Rydzak, Thomas; Garcia, David; Stevenson, David M; Sladek, Margaret; Klingeman, Dawn M; Holwerda, Evert K; Amador-Noguez, Daniel; Brown, Steven D; Guss, Adam M

    2017-05-01

    Clostridium thermocellum rapidly deconstructs cellulose and ferments resulting hydrolysis products into ethanol and other products, and is thus a promising platform organism for the development of cellulosic biofuel production via consolidated bioprocessing. While recent metabolic engineering strategies have targeted eliminating canonical fermentation products (acetate, lactate, formate, and H 2 ), C. thermocellum also secretes amino acids, which has limited ethanol yields in engineered strains to approximately 70% of the theoretical maximum. To investigate approaches to decrease amino acid secretion, we attempted to reduce ammonium assimilation by deleting the Type I glutamine synthetase (glnA) in an essentially wild type strain of C. thermocellum. Deletion of glnA reduced levels of secreted valine and total amino acids by 53% and 44% respectively, and increased ethanol yields by 53%. RNA-seq analysis revealed that genes encoding the RNF-complex were more highly expressed in ΔglnA and may have a role in improving NADH-availability for ethanol production. While a significant up-regulation of genes involved in nitrogen assimilation and urea uptake suggested that deletion of glnA induces a nitrogen starvation response, metabolomic analysis showed an increase in intracellular glutamine levels indicative of nitrogen-rich conditions. We propose that deletion of glnA causes deregulation of nitrogen metabolism, leading to overexpression of nitrogen metabolism genes and, in turn, elevated glutamine levels. Here we demonstrate that perturbation of nitrogen assimilation is a promising strategy to redirect flux from the production of nitrogenous compounds toward biofuels in C. thermocellum. Copyright © 2017. Published by Elsevier Inc.

  18. Effects of feeding polyphenol-rich winery wastes on digestibility, nitrogen utilization, ruminal fermentation, antioxidant status and oxidative stress in wethers.

    Science.gov (United States)

    Ishida, Kyohei; Kishi, Yosuke; Oishi, Kazato; Hirooka, Hiroyuki; Kumagai, Hajime

    2015-03-01

    Four wethers were used in a 4 × 4 Latin square design experiment to evaluate the availability of two types of winery wastes, winery sediment and grape pomace, as ruminant feeds possessing antioxidant activities. Each wether was assigned to one of the following four treatments: (i) 75 g/kg winery sediment (WS) on a dry matter (DM) basis; (ii) 166 g/kg DM winery grape pomace (WP); (iii) control diet (CD; 17 g/kg DM soybean meal);and (iv) only tall fescue hay (TFH; no additive). Winery sediment and grape pomace had high levels of polyphenols and of radical scavenging activities. Feeding with winery sediment and grape pomace did not negatively affect the intake, but it depressed crude protein (CP) digestibility compared with CD (P = 0.052 and P winery wastes decreased ruminal ammonia production (P = 0.089 and P winery sediment and grape pomace decreased urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG; an index of oxidative damages) excretion per day (P winery sediment and grape pomace could alter nitrogen metabolism and/or act as new antioxidants for ruminants. © 2014 Japanese Society of Animal Science.

  19. Studies on nitrogen metabolism in crop plants, 20

    International Nuclear Information System (INIS)

    Oritani, Takashi

    1984-01-01

    Experiment was conducted to examine the translocation rate of three sources of nitrogen supplied as basal-dressing, topdressing 1 (at the spikelet initiation stage) and 2 (at the flowering stage). Most of the 15 N from topdressing 1 was distributed in the upper leaf blades and ears as sink, whereas the distribution of 15 N from basal-dressing was found in the lower leaf blades and leaf sheath + culms. 15 N topdressed at the flowering stage was continuously translocated into sink during the ripening period. The transport into sink of 15 N-labelled ammonium top-dressed at the flowering stage was more rapid than basal-dressed 15 N. Most of the 15 N derived from topdressing at the flowering stage was directly translocated into sink via culms from the roots. (Mori, K.)

  20. Some aspects of nitrogen metabolism in the bovine rumen

    International Nuclear Information System (INIS)

    Nikolic, J.A.

    1976-01-01

    Studies on the use of urea as a source of nitrogen for microbial protein synthesis showed that utilization was more efficient when the protein-N content of the diet was low. However, when the total nitrogen of the dietary dry matter was reduced below 1.9%, there was a drop in the protein-N content of rumen dry matter and a reduction in the daily flow of protein through the duodenum. The mean post-prandial rumen ammonia concentrations were below 5mg NH 3 -N/100ml. In vitro work with 15 N-labelled urea and ammonia salts showed that the overall utilization rate of ammonia was not significantly affected by mean concentrations between 1.6 and 16.7mg/ml, but that net utilization was lower below 5.8mg/100ml. It is suggested that increased lysis of susceptible micro-organisms or increased proteolysis of feed proteins may account for these findings. The concentrations of ammonia-N, protein-N and volatile fatty acids in the rumen were not affected by increases in the amount of calcium, phosphorus, potassium or sulphur in the diet, although the concentrations of these elements were significantly increased in the rumen. A wide dietary Ca/P ratio (3.26) tended to reduce the stability of rumen contents leading to a low pH and foaming. Increases in mean sulphide concentration from 3.6 to 8.0mg/l had no effect on overall protein synthesis rate as indicated by the 35 S incorporation rate. (author)

  1. Effects of weaning age on growth, nutrient digestibility and metabolism, and serum parameters in Hu lambs

    Directory of Open Access Journals (Sweden)

    Jianmin Chai

    2015-12-01

    Full Text Available This study was conducted to investigate the effect of weaning age on growth performance, nutrient digestion and metabolism, and serological indicators, and to obtain an optimal weaning age in Hu lambs. Forty-eight newborn Hu lambs (birth weight, 2.53 ± 0.14 kg were randomly divided into 4 groups. The lambs in control group (ER suckled their dams. The lambs in other three experimental groups were weaned on milk replacer at 10, 20, and 30 days of age (EW10, EW20, and EW30 groups, respectively. The results were as follows: 1 lambs in EW10 and EW30 groups had a lower (P  0.05 among groups; however, the apparent digestibility and deposition of calcium in early weaned lambs were lower (P < 0.05 than those in ewe-reared lambs. 4 The albumin content in EW30 group was lower (P < 0.05 than that in ER group; the globulin content in EW30 group was higher (P < 0.05 than that in other groups; the content of serum insulin-like growth factor-Ⅰ in weaned lambs tended to increase compared with lambs in ER group. Finally, the growth rate of lambs decreased within 10 days post-weaning, but early weaning boosted creep feed intake, leading to better growth and health later in life. The Hu lambs can be weaned on milk replacer and creep feed at 10 days of age.

  2. Impact of feed carbohydrates and nitrogen source on the production of soluble microbial products (SMPs) in anaerobic digestion.

    Science.gov (United States)

    Le, Chencheng; Stuckey, David C

    2017-10-01

    Six stirred fill-and-draw batch reactors with a range of carbohydrate feeds (glucose, fructose and sucrose), and nitrogen sources (NH 4 Cl, urea) at various concentrations were used to investigate the effect of feed composition on the production of soluble microbial products (SMPs) during anaerobic digestion (AD). To gain greater insights into the SMPs produced, the composition of various fractions was analyzed, while the low molecular weight (MW) SMPs generated with different feeds and nutrients were collected and chemically analyzed using GC-MS. Other organic solutes such as free amino acids were determined using HPLC, and this level of chemical analysis has never been carried out in past work because of analytical limitations. It was found that the presence of ammonium salts rather than urea at 200 mg/L stimulated the production of not only volatile fatty acids, but also SMPs of different MW fractions, and reduced the production of biogas significantly. The study also revealed that the type of SMP that dominates in a particular system depends on the chemical characteristics of the feed, and this insight has implications on the composition of the effluent from anaerobic digesters (and their potential chlorination by-products), and membrane fouling in membrane bioreactors. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Novel metabolic attributes of the genus cyanothece, comprising a group of unicellular nitrogen-fixing Cyanothece.

    Science.gov (United States)

    Bandyopadhyay, Anindita; Elvitigala, Thanura; Welsh, Eric; Stöckel, Jana; Liberton, Michelle; Min, Hongtao; Sherman, Louis A; Pakrasi, Himadri B

    2011-01-01

    The genus Cyanothece comprises unicellular cyanobacteria that are morphologically diverse and ecologically versatile. Studies over the last decade have established members of this genus to be important components of the marine ecosystem, contributing significantly to the nitrogen and carbon cycle. System-level studies of Cyanothece sp. ATCC 51142, a prototypic member of this group, revealed many interesting metabolic attributes. To identify the metabolic traits that define this class of cyanobacteria, five additional Cyanothece strains were sequenced to completion. The presence of a large, contiguous nitrogenase gene cluster and the ability to carry out aerobic nitrogen fixation distinguish Cyanothece as a genus of unicellular, aerobic nitrogen-fixing cyanobacteria. Cyanothece cells can create an anoxic intracellular environment at night, allowing oxygen-sensitive processes to take place in these oxygenic organisms. Large carbohydrate reserves accumulate in the cells during the day, ensuring sufficient energy for the processes that require the anoxic phase of the cells. Our study indicates that this genus maintains a plastic genome, incorporating new metabolic capabilities while simultaneously retaining archaic metabolic traits, a unique combination which provides the flexibility to adapt to various ecological and environmental conditions. Rearrangement of the nitrogenase cluster in Cyanothece sp. strain 7425 and the concomitant loss of its aerobic nitrogen-fixing ability suggest that a similar mechanism might have been at play in cyanobacterial strains that eventually lost their nitrogen-fixing ability. The unicellular cyanobacterial genus Cyanothece has significant roles in the nitrogen cycle in aquatic and terrestrial environments. Cyanothece sp. ATCC 51142 was extensively studied over the last decade and has emerged as an important model photosynthetic microbe for bioenergy production. To expand our understanding of the distinctive metabolic capabilities of

  4. Nitrogen metabolism and kinetics of ammonia-oxidizing archaea.

    Science.gov (United States)

    Martens-Habbena, Willm; Stahl, David A

    2011-01-01

    The discovery of ammonia-oxidizing mesophilic and thermophilic Group I archaea changed the century-old paradigm that aerobic ammonia oxidation is solely mediated by two small clades of Beta- and Gammaproteobacteria. Group I archaea are extremely diverse and ubiquitous in marine and terrestrial environments, accounting for 20-30% of the microbial plankton in the global oceans. Recent studies indicated that many of these organisms carry putative ammonia monooxygenase genes and are more abundant than ammonia-oxidizing bacteria in most natural environments suggesting a potentially significant role in the nitrogen cycle. The isolation of Nitrosopumilus maritimus strain SCM1 provided the first direct evidence that Group I archaea indeed gain energy from ammonia oxidation. To characterize the physiology of this archaeal nitrifier, we developed a respirometry setup particularly suited for activity measurements in dilute microbial cultures with extremely low oxygen uptake rates. Here, we describe the setup and review the kinetic experiments conducted with N. maritimus and other nitrifying microorganisms. These experiments demonstrated that N. maritimus is adapted to grow on ammonia concentrations found in oligotrophic open ocean environments, far below the survival threshold of ammonia-oxidizing bacteria. The described setup and experimental procedures should facilitate physiological studies on other nitrifying archaea and oligotrophic microorganisms in general. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Response of nitrogen metabolism to boron toxicity in tomato plants.

    Science.gov (United States)

    Cervilla, L M; Blasco, B; Ríos, J J; Rosales, M A; Rubio-Wilhelmi, M M; Sánchez-Rodríguez, E; Romero, L; Ruiz, J M

    2009-09-01

    Boron (B) toxicity has become important in areas close to the Mediterranean Sea where intensive agriculture has been developed. The objective of this research was to study the effects of B toxicity (0.5 mM and 2.0 mM B) on nitrogen (N) assimilation of two tomato cultivars that are often used in these areas. Leaf biomass, relative leaf growth rate (RGR(L)), concentration of B, nitrate (NO(3) (-)), ammonium (NH(4) (+)), organic N, amino acids and soluble proteins, as well as nitrate reductase (NR), nitrite reductase (NiR), glutamine synthase (GS), glutamate synthetase (GOGAT) and glutamate dehydrogenase (GDH) activities were analysed in leaves. Boron toxicity significantly decreased leaf biomass, RGR(L), organic N, soluble proteins, and NR and NiR activities. The lowest NO(3) (-) and NH(4) (+) concentration in leaves was recorded when plants were supplied with 2.0 mM B in the root medium. Total B, amino acids, activities of GS, GOGAT and GDH increased under B toxicity. Data from the present study prove that B toxicity causes inhibition of NO(3) (-) reduction and increases NH(4) (+) assimilation in tomato plants.

  6. Synthetic control of a fitness tradeoff in yeast nitrogen metabolism

    Directory of Open Access Journals (Sweden)

    Lee Jack J

    2009-01-01

    Full Text Available Abstract Background Microbial communities are involved in many processes relevant to industrial and medical biotechnology, such as the formation of biofilms, lignocellulosic degradation, and hydrogen production. The manipulation of synthetic and natural microbial communities and their underlying ecological parameters, such as fitness, evolvability, and variation, is an increasingly important area of research for synthetic biology. Results Here, we explored how synthetic control of an endogenous circuit can be used to regulate a tradeoff between fitness in resource abundant and resource limited environments in a population of Saccharomyces cerevisiae. We found that noise in the expression of a key enzyme in ammonia assimilation, Gdh1p, mediated a tradeoff between growth in low nitrogen environments and stress resistance in high ammonia environments. We implemented synthetic control of an endogenous Gdh1p regulatory network to construct an engineered strain in which the fitness of the population was tunable in response to an exogenously-added small molecule across a range of ammonia environments. Conclusion The ability to tune fitness and biological tradeoffs will be important components of future efforts to engineer microbial communities.

  7. Fatty Acid Metabolism in the Digestive Tract of Lactating Cows Fed Tallow in Increasing Amounts at Two Feed Levels

    DEFF Research Database (Denmark)

    Weisbjerg, Martin Riis; Børsting, Christian Friis; Hvelplund, Torben

    1992-01-01

    Long-chain fatty acid metabolism in the digestive tract was studied in lactating cows fed at two levels of dry matter intake (L, 8.6 kg DM and H, 12.6 kg DM), with 0, 4 and 6% added tallow at low feed level (L0, L4 and L6), and 0, 2, 4 and 6% fat at high feed level (H0, H2, H4 and H6). Mean fatty...... in the diet. As a mean 68% of the unsaturated C18 fatty acids were hydrogenated in the rumen. Fatty acid and crude fat true digestibilities decreased with increasing fat intakes owing to a decrease in stearic acid (C18:0) digestibility....

  8. Integration of Carbon, Nitrogen, and Oxygen Metabolism in Escherichia coli

    Science.gov (United States)

    2012-10-22

    optimally, balancing effectively the conversion of carbon into energy versus biomass . To investigate the link between the metabolism of different nutrients...diverse nutrient conditions, E. coli  grows nearly optimally, balancing effectively the  conversion  of carbon  into energy versus  biomass . Here we  show... enzymatic  connections, with kinetic parameters taken from the  literature or computationally  inferred  based on  the data  from Aim 1. As proposed  initially

  9. Consumo e digestibilidade de feno de baixa qualidade suplementado com nitrogênio não protéico em bovinos Intake and digestibility of low-quality hay with nonprotein nitrogen supplementation in cattle

    Directory of Open Access Journals (Sweden)

    Giovanni Mateus Mallmann

    2006-02-01

    detergent fiber. Digestibility of organic matter, organic matter of forage, neutral detergent fiber, cellulose and hemicellulose were not affected by nonprotein nitrogen level; total intake of these components showed a quadratic response to nonprotein nitrogen supplementation. Organic matter metabolic fecal excretion was not affected by supplementation, suggesting a simultaneous increase in both passage (intake increase and digestion rates (stable digestibility. The digestible organic matter intake showed a quadratic response with the increase of urea supplementation levels. The relationship between rumen degradable protein intake and digestible organic matter intake showed a maximization point, when rumen degradable protein intake was equivalent to 8.1% of digestible organic matter intake.

  10. Effect of shrimp ( Litopenaeus vannamei) farming waste on the growth, digestion, ammonium-nitrogen excretion of sea cucumber ( Stichopus monotuberculatus)

    Science.gov (United States)

    Chen, Yanfeng; Luo, Peng; Hu, Chaoqun; Ren, Chunhua

    2015-06-01

    In this study, specific growth rate (SGR), ingestion rate (IR), food conversion ratio (FCR), apparent digestion ratio (ADR) and ammonium-nitrogen excretion were determined for sea cucumber ( Stichopus monotuberculatus) reared in plastic containers (70 L; 4 containers each diet treatment). Sea cucumbers were fed with five diets containing different amounts of farming waste from shrimp ( Litopenaeus vannamei) (100%, 75%, 50%, 25% and 0) and a formulated compound (20% sea mud and 80% powdered algae). Sea cucumbers grew faster when they were fed with diet D (25% shrimp waste and 75% formulated compound) than those fed with other diets. Although IR value of sea cucumber fed with diet A (shrimp waste) was higher than those fed with other diets, both the lowest SGR and the highest FCR occurred in this diet group. The highest and the lowest ADR occurred in diet E (formulated compound) and diet A group, respectively, and the same to ammonium-nitrogen excretion. The contents of crude protein, crude lipid and total organic matter (TOM) in feces decreased in comparison with corresponding diets. In the feces from different diet treatments, the contents of crude protein and TOM increased gradually as the contents of crude protein and TOM in diets increased, while crude lipid content decreased gradually as the crude lipid content in diets increased.

  11. Arsenic induces structural and compositional colonic microbiome change and promotes host nitrogen and amino acid metabolism

    International Nuclear Information System (INIS)

    Dheer, Rishu; Patterson, Jena; Dudash, Mark; Stachler, Elyse N.; Bibby, Kyle J.; Stolz, Donna B.; Shiva, Sruti; Wang, Zeneng; Hazen, Stanley L.; Barchowsky, Aaron; Stolz, John F.

    2015-01-01

    Chronic exposure to arsenic in drinking water causes cancer and non-cancer diseases. However, mechanisms for chronic arsenic-induced pathogenesis, especially in response to lower exposure levels, are unclear. In addition, the importance of health impacts from xeniobiotic-promoted microbiome changes is just being realized and effects of arsenic on the microbiome with relation to disease promotion are unknown. To investigate impact of arsenic exposure on both microbiome and host metabolism, the stucture and composition of colonic microbiota, their metabolic phenotype, and host tissue and plasma metabolite levels were compared in mice exposed for 2, 5, or 10 weeks to 0, 10 (low) or 250 (high) ppb arsenite (As(III)). Genotyping of colonic bacteria revealed time and arsenic concentration dependent shifts in community composition, particularly the Bacteroidetes and Firmicutes, relative to those seen in the time-matched controls. Arsenic-induced erosion of bacterial biofilms adjacent to the mucosal lining and changes in the diversity and abundance of morphologically distinct species indicated changes in microbial community structure. Bacterical spores increased in abundance and intracellular inclusions decreased with high dose arsenic. Interestingly, expression of arsenate reductase (arsA) and the As(III) exporter arsB, remained unchanged, while the dissimilatory nitrite reductase (nrfA) gene expression increased. In keeping with the change in nitrogen metabolism, colonic and liver nitrite and nitrate levels and ratios changed with time. In addition, there was a concomitant increase in pathogenic arginine metabolites in the mouse circulation. These data suggest that arsenic exposure impacts the microbiome and microbiome/host nitrogen metabolism to support disease enhancing pathogenic phenotypes. - Highlights: • Arsenic exposure induces changes in host and host nitrogen metabolism that cause progresive change in the microbiome. • A polyphasic approach reveals changes

  12. Evolutionary convergence and nitrogen metabolism in Blattabacterium strain Bge, primary endosymbiont of the cockroach Blattella germanica.

    Directory of Open Access Journals (Sweden)

    Maria J López-Sánchez

    2009-11-01

    Full Text Available Bacterial endosymbionts of insects play a central role in upgrading the diet of their hosts. In certain cases, such as aphids and tsetse flies, endosymbionts complement the metabolic capacity of hosts living on nutrient-deficient diets, while the bacteria harbored by omnivorous carpenter ants are involved in nitrogen recycling. In this study, we describe the genome sequence and inferred metabolism of Blattabacterium strain Bge, the primary Flavobacteria endosymbiont of the omnivorous German cockroach Blattella germanica. Through comparative genomics with other insect endosymbionts and free-living Flavobacteria we reveal that Blattabacterium strain Bge shares the same distribution of functional gene categories only with Blochmannia strains, the primary Gamma-Proteobacteria endosymbiont of carpenter ants. This is a remarkable example of evolutionary convergence during the symbiotic process, involving very distant phylogenetic bacterial taxa within hosts feeding on similar diets. Despite this similarity, different nitrogen economy strategies have emerged in each case. Both bacterial endosymbionts code for urease but display different metabolic functions: Blochmannia strains produce ammonia from dietary urea and then use it as a source of nitrogen, whereas Blattabacterium strain Bge codes for the complete urea cycle that, in combination with urease, produces ammonia as an end product. Not only does the cockroach endosymbiont play an essential role in nutrient supply to the host, but also in the catabolic use of amino acids and nitrogen excretion, as strongly suggested by the stoichiometric analysis of the inferred metabolic network. Here, we explain the metabolic reasons underlying the enigmatic return of cockroaches to the ancestral ammonotelic state.

  13. Evolutionary Convergence and Nitrogen Metabolism in Blattabacterium strain Bge, Primary Endosymbiont of the Cockroach Blattella germanica

    Science.gov (United States)

    López-Sánchez, Maria J.; Neef, Alexander; Peretó, Juli; Patiño-Navarrete, Rafael; Pignatelli, Miguel; Latorre, Amparo; Moya, Andrés

    2009-01-01

    Bacterial endosymbionts of insects play a central role in upgrading the diet of their hosts. In certain cases, such as aphids and tsetse flies, endosymbionts complement the metabolic capacity of hosts living on nutrient-deficient diets, while the bacteria harbored by omnivorous carpenter ants are involved in nitrogen recycling. In this study, we describe the genome sequence and inferred metabolism of Blattabacterium strain Bge, the primary Flavobacteria endosymbiont of the omnivorous German cockroach Blattella germanica. Through comparative genomics with other insect endosymbionts and free-living Flavobacteria we reveal that Blattabacterium strain Bge shares the same distribution of functional gene categories only with Blochmannia strains, the primary Gamma-Proteobacteria endosymbiont of carpenter ants. This is a remarkable example of evolutionary convergence during the symbiotic process, involving very distant phylogenetic bacterial taxa within hosts feeding on similar diets. Despite this similarity, different nitrogen economy strategies have emerged in each case. Both bacterial endosymbionts code for urease but display different metabolic functions: Blochmannia strains produce ammonia from dietary urea and then use it as a source of nitrogen, whereas Blattabacterium strain Bge codes for the complete urea cycle that, in combination with urease, produces ammonia as an end product. Not only does the cockroach endosymbiont play an essential role in nutrient supply to the host, but also in the catabolic use of amino acids and nitrogen excretion, as strongly suggested by the stoichiometric analysis of the inferred metabolic network. Here, we explain the metabolic reasons underlying the enigmatic return of cockroaches to the ancestral ammonotelic state. PMID:19911043

  14. Arsenic induces structural and compositional colonic microbiome change and promotes host nitrogen and amino acid metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Dheer, Rishu; Patterson, Jena; Dudash, Mark [Department of Biological Sciences, Duquesne University, Pittsburgh, PA 15282 (United States); Stachler, Elyse N.; Bibby, Kyle J. [Department of Civil and Environmental Engineering, University of Pittsburgh Swanson School of Engineering, Pittsburgh, PA 15261 (United States); Stolz, Donna B. [Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261 (United States); Shiva, Sruti [Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh 15261 (United States); Vascular Medicine Institute, University of Pittsburgh, Pittsburgh 15261 (United States); Wang, Zeneng; Hazen, Stanley L. [Department of Cellular and Molecular Medicine, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195 (United States); Barchowsky, Aaron, E-mail: aab20@pitt.edu [Department of Pharmacology and Chemical Biology, University of Pittsburgh, Pittsburgh 15261 (United States); Vascular Medicine Institute, University of Pittsburgh, Pittsburgh 15261 (United States); Department of Environmental and Occupational Health, University of Pittsburgh Graduate School of Public Health, Pittsburgh, PA 15219 (United States); Stolz, John F. [Department of Biological Sciences, Duquesne University, Pittsburgh, PA 15282 (United States)

    2015-12-15

    Chronic exposure to arsenic in drinking water causes cancer and non-cancer diseases. However, mechanisms for chronic arsenic-induced pathogenesis, especially in response to lower exposure levels, are unclear. In addition, the importance of health impacts from xeniobiotic-promoted microbiome changes is just being realized and effects of arsenic on the microbiome with relation to disease promotion are unknown. To investigate impact of arsenic exposure on both microbiome and host metabolism, the stucture and composition of colonic microbiota, their metabolic phenotype, and host tissue and plasma metabolite levels were compared in mice exposed for 2, 5, or 10 weeks to 0, 10 (low) or 250 (high) ppb arsenite (As(III)). Genotyping of colonic bacteria revealed time and arsenic concentration dependent shifts in community composition, particularly the Bacteroidetes and Firmicutes, relative to those seen in the time-matched controls. Arsenic-induced erosion of bacterial biofilms adjacent to the mucosal lining and changes in the diversity and abundance of morphologically distinct species indicated changes in microbial community structure. Bacterical spores increased in abundance and intracellular inclusions decreased with high dose arsenic. Interestingly, expression of arsenate reductase (arsA) and the As(III) exporter arsB, remained unchanged, while the dissimilatory nitrite reductase (nrfA) gene expression increased. In keeping with the change in nitrogen metabolism, colonic and liver nitrite and nitrate levels and ratios changed with time. In addition, there was a concomitant increase in pathogenic arginine metabolites in the mouse circulation. These data suggest that arsenic exposure impacts the microbiome and microbiome/host nitrogen metabolism to support disease enhancing pathogenic phenotypes. - Highlights: • Arsenic exposure induces changes in host and host nitrogen metabolism that cause progresive change in the microbiome. • A polyphasic approach reveals changes

  15. Water intake and digestive metabolism of broilers fed all-vegetable diets containing acidulated soybean soapstock

    Directory of Open Access Journals (Sweden)

    SL Vieira

    2006-09-01

    Full Text Available A study was conducted to compare live performance and digestive metabolism of broiler chickens fed all-vegetable diets (All-Veg compared to a regular diet including animal by-products. Three feeds were formulated and provided to broilers according to the feeding program: pre-starter from 1 to 10 days, starter from 11 to 21 days, and grower from 21 to 35 days. All feeds had corn and soybean meal as major ingredients; however, two of them were all-vegetable diets having either Degummed Soybean Oil (DSO or Acidulated Soybean Soapstock (ASS as fat sources. The third diet included poultry by-product and poultry fat. A total number of 360 day-old broiler chicks were allocated to 1m² battery cages, 10 chicks in each, and 12 replicates per treatment. Live performance was similar between groups of birds receiving the different diets with the exception of weight gain, which was increased for birds fed the All-Veg diet with ASS. Birds fed All-Veg diets had increased water intake and produced more excreta with a concurrent reduced feed metabolizability at both ages, regardless of fat source. Metabolizable Energy was not different for the three diets.

  16. Effect of dietary fiber, genetic strain and age on the digestive metabolism of broiler chickens

    Directory of Open Access Journals (Sweden)

    RV Krás

    2013-06-01

    Full Text Available In this study, 360 male broilers, out of which 240 of a fast-growing strain (Cobb500, and 120 of a slow-growing strain (Label Rouge, were used to evaluate the effect of dietary fiber on digesta transit time and digestive metabolism during the period of 1 to 42 days of age. A completely randomized experimental design with a 3x2 factorial arrangement was applied, consisting of three groups of birds (slow-growing - SG; fast-growing fed ad libitum - FGAL; and fast-growing pair-fed with SG broilers - FGPF and two iso-protein diets (a 3100 kcal ME/kg low-fiber diet - LFD- and a 2800 kcal ME/kg high-fiber diet - HFD- with 14% wheat bran and 4% oat hulls. HFD-fed birds presented lower ME retention (p < 0.001 and lower dry matter metabolizability (DMM (p < 0.001, which is possibly related to the shorter digesta transit time observed in these birds (p < 0.001. DMM was reduced with age, whereas metabolizable energy remained almost constant (p < 0.001 independently of strain. This may be related to the increase in feed intake as birds age. The slow-growing strain did not present better utilization of the high-fiber diet as compared to the fast-growing strain in none of the analyzed ages, even though showing a significant better use of fiber and dietary energy from 31 days of age.

  17. Nitrogen Metabolite Repression of Metabolism and Virulence in the Human Fungal Pathogen Cryptococcus neoformans

    Science.gov (United States)

    Lee, I. Russel; Chow, Eve W. L.; Morrow, Carl A.; Djordjevic, Julianne T.; Fraser, James A.

    2011-01-01

    Proper regulation of metabolism is essential to maximizing fitness of organisms in their chosen environmental niche. Nitrogen metabolite repression is an example of a regulatory mechanism in fungi that enables preferential utilization of easily assimilated nitrogen sources, such as ammonium, to conserve resources. Here we provide genetic, transcriptional, and phenotypic evidence of nitrogen metabolite repression in the human pathogen Cryptococcus neoformans. In addition to loss of transcriptional activation of catabolic enzyme-encoding genes of the uric acid and proline assimilation pathways in the presence of ammonium, nitrogen metabolite repression also regulates the production of the virulence determinants capsule and melanin. Since GATA transcription factors are known to play a key role in nitrogen metabolite repression, bioinformatic analyses of the C. neoformans genome were undertaken and seven predicted GATA-type genes were identified. A screen of these deletion mutants revealed GAT1, encoding the only global transcription factor essential for utilization of a wide range of nitrogen sources, including uric acid, urea, and creatinine—three predominant nitrogen constituents found in the C. neoformans ecological niche. In addition to its evolutionarily conserved role in mediating nitrogen metabolite repression and controlling the expression of catabolic enzyme and permease-encoding genes, Gat1 also negatively regulates virulence traits, including infectious basidiospore production, melanin formation, and growth at high body temperature (39°–40°). Conversely, Gat1 positively regulates capsule production. A murine inhalation model of cryptococcosis revealed that the gat1Δ mutant is slightly more virulent than wild type, indicating that Gat1 plays a complex regulatory role during infection. PMID:21441208

  18. Nitrogen mineralization from sheep faeces can be predicted from the apparent digestibility of the feed

    DEFF Research Database (Denmark)

    Kyvsgaard, P.; Sørensen, P.; Møller, E.

    2000-01-01

    It is difficult to predict plant availability of N in faeces because most faecal N is bound in organic form. In this study the influence of diet and faeces composition on mineralization of sheep faeces in soil were investigated. Net mineralization of C and N from 16 different samples of sheep...... faeces originating from sheep fed different known diets was studied after incubation in a sandy soil. After 4 weeks net mineralization of N ranged from -41 to 9% of faeces N and after 12 weeks -28 to 43% was net mineralized. Mineralization was related to different feed and faeces characteristics...... of the mineralization of sheep faeces N in soil based on chemical analyses of the feed. However, when using a biological measure of the feed quality (apparent digestibility) a robust prediction of faeces N mineralization was possible....

  19. Redução do tempo de digestão na determinação de nitrogênio em solos Reduction of digestion time in the determination of total nitrogen in soils

    Directory of Open Access Journals (Sweden)

    Flávio Verlengia

    1968-01-01

    Full Text Available Foi estudada a redução do tempo de digestão na determinação do nitrogênio total em solos, assim como a perda dêsse nutriente durante a sua determinação. Procurou-se comparar o efeito de alguns catalisadores, como sulfato de cobre, óxido de mercúrio e selênio. Diversos tempos de ataques foram estudados, desde 10 até 960 minutos (16 horas. Verificou-se que as maiores reduções de tempo foram obtidas com o selênio, utilizado como catalisador, em presença de óxido de mercúrio, particularmente em solos onde o ataque se mostrou mais difícil. O catalisador tradicional - sulfato de cobre - foi o menos eficiente. A utilização do selênio, não provocou perda de nitrogênio durante a digestão.By using the Kjeldahl method in the determination of total nitrogen in soils, the effect of various catalysts related with digestion time and with possible nitrogen losses was studied. The experiment was carried out by using the catalysts CuSO4.5H2O; HgO and Se in six treatments. Results indicated that a pronounced reduction on digestion time was obtained by using selenium as catalyst. Best results, however, were obtained by using a mixture of selenium and mercury oxide, principally for soils of very difficult digestion (organic soil and "terra roxa" soil. In all treatments CuSO4.5H2O was the less efficient. Use of selenium did not cause loss of nitrogen.

  20. Urease Activity Represents an Alternative Pathway for Mycobacterium tuberculosis Nitrogen Metabolism

    Science.gov (United States)

    Lin, Wenwei; Mathys, Vanessa; Ang, Emily Lei Yin; Koh, Vanessa Hui Qi; Martínez Gómez, Julia María; Ang, Michelle Lay Teng; Zainul Rahim, Siti Zarina; Tan, Mai Ping; Pethe, Kevin

    2012-01-01

    Urease represents a critical virulence factor for some bacterial species through its alkalizing effect, which helps neutralize the acidic microenvironment of the pathogen. In addition, urease serves as a nitrogen source provider for bacterial growth. Pathogenic mycobacteria express a functional urease, but its role during infection has yet to be characterized. In this study, we constructed a urease-deficient Mycobacterium tuberculosis strain and confirmed the alkalizing effect of the urease activity within the mycobacterium-containing vacuole in resting macrophages but not in the more acidic phagolysosomal compartment of activated macrophages. However, the urease-mediated alkalizing effect did not confer any growth advantage on M. tuberculosis in macrophages, as evidenced by comparable growth profiles for the mutant, wild-type (WT), and complemented strains. In contrast, the urease-deficient mutant exhibited impaired in vitro growth compared to the WT and complemented strains when urea was the sole source of nitrogen. Substantial amounts of ammonia were produced by the WT and complemented strains, but not with the urease-deficient mutant, which represents the actual nitrogen source for mycobacterial growth. However, the urease-deficient mutant displayed parental colonization profiles in the lungs, spleen, and liver in mice. Together, our data demonstrate a role for the urease activity in M. tuberculosis nitrogen metabolism that could be crucial for the pathogen's survival in nutrient-limited microenvironments where urea is the sole nitrogen source. Our work supports the notion that M. tuberculosis virulence correlates with its unique metabolic versatility and ability to utilize virtually any carbon and nitrogen sources available in its environment. PMID:22645285

  1. Emersion induces nitrogen release and alteration of nitrogen metabolism in the intertidal genus Porphyra.

    Directory of Open Access Journals (Sweden)

    Jang K Kim

    Full Text Available We investigated emersion-induced nitrogen (N release from Porphyra umbilicalis Kütz. Thallus N concentration decreased during 4 h of emersion. Tissue N and soluble protein contents of P. umbilicalis were positively correlated and decreased during emersion. Growth of P. umbilicalis did not simply dilute the pre-emersion tissue N concentration. Rather, N was lost from tissues during emersion. We hypothesize that emersion-induced N release occurs when proteins are catabolized. While the δ(15N value of tissues exposed to emersion was higher than that of continuously submerged tissues, further discrimination of stable N isotopes did not occur during the 4 h emersion. We conclude that N release from Porphyra during emersion did not result from bacterial denitrification, but possibly as a consequence of photorespiration. The release of N by P. umbilicalis into the environment during emersion suggests a novel role of intertidal seaweeds in the global N cycle. Emersion also altered the physiological function (nitrate uptake, nitrate reductase and glutamine synthetase activity, growth rate of P. umbilicalis and the co-occurring upper intertidal species P. linearis Grev., though in a seasonally influenced manner. Individuals of the year round perennial species P. umbilicalis were more tolerant of emersion than ephemeral, cold temperate P. linearis in early winter. However, the mid-winter populations of both P. linearis and P. umbilicalis, had similar temporal physiological patterns during emersion.

  2. Specific effects of certain salts on nitrogen metabolism of young corn seedlings

    Directory of Open Access Journals (Sweden)

    Mohammad Hatata

    2014-01-01

    Full Text Available The effect of sodium and magnesium chlorides and sulphates on nitrogen metabolism of corn seedlings and their constituent parts have been studied. Treatment with all salts led to a decrease in the nitrogen content of the seedling as a whole, and the decrease became more pronounced with the increase of salt concentration, though these concentrations were too low to induce any osmotic action. The same trend of changes was noticed as regards nonprotein-N, whereas the opposite was recorded in reference to the changes; of protein-N. Higher concentrations of the salt solutions led to leaching out of more nonprotein-N than did lower concentrations. The study of the distribution of nitrogenous constituents among the different organs of the seedling showed that while the total-N content of the whole seedling decreased with the increase of salt concentration, the total-N content of the roots decreased markedly, and the total-N content of the tops decreased also but less whereas, the total-N content of the grains increased with the increase of salt concentration as compared with that in the control. As a result of disturbances of nitrogen metabolism under salinization, more ammonia and amides were accumulated in all seedling organs.

  3. Coupled effects of light and nitrogen source on the urea cycle and nitrogen metabolism over a diel cycle in the marine diatom Thalassiosira pseudonana.

    Science.gov (United States)

    Bender, Sara J; Parker, Micaela S; Armbrust, E Virginia

    2012-03-01

    Diatoms are photoautotrophic organisms capable of growing on a variety of inorganic and organic nitrogen sources. Discovery of a complete urea cycle in diatoms was surprising, as this pathway commonly functions in heterotrophic organisms to rid cells of waste nitrogen. To determine how the urea cycle is integrated into cellular nitrogen metabolism and energy management, the centric diatom Thalassiosira pseudonana was maintained in semi-continuous batch cultures on nitrate, ammonium, or urea as the sole nitrogen source, under a 16: 8 light: dark cycle and at light intensities that were low, saturating, or high for growth. Steady-state transcript levels were determined for genes encoding enzymes linked to the urea cycle, urea hydrolysis, glutamine synthesis, pyrimidine synthesis, photorespiration, and energy storage. Transcript abundances were significantly affected by nitrogen source, light intensity and a diel cycle. The impact of N source on differential transcript accumulation was most apparent under the highest light intensity. Models of cellular metabolism under high light were developed based on changes in transcript abundance and predicted enzyme localizations. We hypothesize that the urea cycle is integrated into nitrogen metabolism through its connection to glutamine and in the eventual production of urea. These findings have important implications for nitrogen flow in the cell over diel cycles at surface ocean irradiances. Copyright © 2011 Elsevier GmbH. All rights reserved.

  4. In Vivo Analysis of NH4+ Transport and Central Nitrogen Metabolism in Saccharomyces cerevisiae during Aerobic Nitrogen-Limited Growth

    Science.gov (United States)

    Maleki Seifar, R.; ten Pierick, A.; van Helmond, W.; Pieterse, M. M.; Heijnen, J. J.

    2016-01-01

    ABSTRACT Ammonium is the most common N source for yeast fermentations. Although its transport and assimilation mechanisms are well documented, there have been only a few attempts to measure the in vivo intracellular concentration of ammonium and assess its impact on gene expression. Using an isotope dilution mass spectrometry (IDMS)-based method, we were able to measure the intracellular ammonium concentration in N-limited aerobic chemostat cultivations using three different N sources (ammonium, urea, and glutamate) at the same growth rate (0.05 h−1). The experimental results suggest that, at this growth rate, a similar concentration of intracellular (IC) ammonium, about 3.6 mmol NH4+/literIC, is required to supply the reactions in the central N metabolism, independent of the N source. Based on the experimental results and different assumptions, the vacuolar and cytosolic ammonium concentrations were estimated. Furthermore, we identified a futile cycle caused by NH3 leakage into the extracellular space, which can cost up to 30% of the ATP production of the cell under N-limited conditions, and a futile redox cycle between Gdh1 and Gdh2 reactions. Finally, using shotgun proteomics with protein expression determined relative to a labeled reference, differences between the various environmental conditions were identified and correlated with previously identified N compound-sensing mechanisms. IMPORTANCE In our work, we studied central N metabolism using quantitative approaches. First, intracellular ammonium was measured under different N sources. The results suggest that Saccharomyces cerevisiae cells maintain a constant NH4+ concentration (around 3 mmol NH4+/literIC), independent of the applied nitrogen source. We hypothesize that this amount of intracellular ammonium is required to obtain sufficient thermodynamic driving force. Furthermore, our calculations based on thermodynamic analysis of the transport mechanisms of ammonium suggest that ammonium is not equally

  5. Optimizing feeding composition and carbon-nitrogen ratios for improved methane yield during anaerobic co-digestion of dairy, chicken manure and wheat straw.

    Science.gov (United States)

    Wang, Xiaojiao; Yang, Gaihe; Feng, Yongzhong; Ren, Guangxin; Han, Xinhui

    2012-09-01

    This study investigated the possibilities of improving methane yield from anaerobic digestion of multi-component substrates, using a mixture of dairy manure (DM), chicken manure (CM) and wheat straw (WS), based on optimized feeding composition and the C/N ratio. Co-digestion of DM, CM and WS performed better in methane potential than individual digestion. A larger synergetic effect in co-digestion of DM, CM and WS was found than in mixtures of single manures with WS. As the C/N ratio increased, methane potential initially increased and then declined. C/N ratios of 25:1 and 30:1 had better digestion performance with stable pH and low concentrations of total ammonium nitrogen and free NH(3). Maximum methane potential was achieved with DM/CM of 40.3:59.7 and a C/N ratio of 27.2:1 after optimization using response surface methodology. The results suggested that better performance of anaerobic co-digestion can be fulfilled by optimizing feeding composition and the C/N ratio. Copyright © 2012 Elsevier Ltd. All rights reserved.

  6. Redistribution of metabolic fluxes in Chlorella protothecoides by variation of media nitrogen concentration

    Directory of Open Access Journals (Sweden)

    Saratram Gopalakrishnan

    2015-12-01

    Full Text Available In this study, the Elementary Metabolite Unit (EMU algorithm was employed to calculate intracellular fluxes for Chlorella protothecoides using previously generated growth and mass spec data. While the flux through glycolysis remained relatively constant, the pentose phosphate pathway (PPP flux increased from 3% to 20% of the glucose uptake during nitrogen-limited growth. The TCA cycle flux decreased from 94% to 38% during nitrogen-limited growth while the flux of acetyl-CoA into lipids increased from 58% to 109% of the glucose uptake, increasing total lipid accumulation. Phosphoenolpyruvate carboxylase (PEPCase activity was higher during nitrogen-sufficient growth. The glyoxylate shunt was found to be partially active in both cases, indicating the nutrient nature has an impact on flux distribution. It was found that the total NADPH supply within the cell remained almost constant under both conditions. In summary, algal cells substantially reorganize their metabolism during the switch from carbon-limited (nitrogen-sufficient to nitrogen-limited (carbon-sufficient growth. Keywords: Microalgae, Biofuels, Chlorella, MFA, EMU algorithm

  7. Enhancement options for the utilisation of nitrogen rich animal by-products in anaerobic digestion.

    Science.gov (United States)

    Resch, Christoph; Wörl, Alexander; Waltenberger, Reinhold; Braun, Rudolf; Kirchmayr, Roland

    2011-02-01

    This study focuses on the enhancement of an Austrian anaerobic digestion plant at a slaughterhouse site which exclusively uses animal by-products as substrate. High ammonia concentrations from protein degradation cause severe inhibitions of anaerobic microorganisms. For improving the current situation the COD:TKN ratio is widened by (a) ammonia stripping directly out of the process and (b) addition of a C source to the substrate. Different OLR and HRT were tested in continuous experiments to simulate new operating conditions. The results show that the addition of carbon cannot improve fermentation capacity. The reduction of ammonia boosts the degradation: After reduction of TKN from 7.5 to 4.0 g kg(-1) the initially high VFA concentration decreased and the COD degradation was improved by 55.5%. Hence, the implementation of the new N reduction process facilitates either the increase of the OLR by 61% or the reduction of the HRT by 25%. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Effects of lanthanum(III) on nitrogen metabolism of soybean seedlings under elevated UV-B radiation.

    Science.gov (United States)

    Cao, Rui; Huang, Xiao-hua; Zhou, Qing; Cheng, Xiao-ying

    2007-01-01

    The hydroponic culture experiments of soybean bean seedlings were conducted to investigate the effect of lanthanum (La) on nitrogen metabolism under two different levels of elevated UV-B radiation (UV-B, 280-320 nm). The whole process of nitrogen metabolism involves uptake and transport of nitrate, nitrate assimilation, ammonium assimilation, amino acid biosynthesis, and protein synthesis. Compared with the control, UV-B radiation with the intensity of low level 0.15 W/m2 and high level 0.45 W/m2 significantly affected the whole nitrogen metabolism in soybean seedlings (p nitrogen-metabolism-related enzymes, such as: nitrate reductase (NR) to the nitrate reduction, glutamine systhetase (GS) and glutamine synthase (GOGAT) to the ammonia assimilation, while it increased the content of free amino acids and decreased that of soluble protein as well. The damage effect of high level of UV-B radiation on nitrogen metabolism was greater than that of low level. And UV-B radiation promoted the activity of the anti-adversity enzyme glutamate dehydrogenase (GDH), which reduced the toxicity of excess ammonia in plant. After pretreatment with the optimum concentration of La (20 mg/L), La could increase the activity of NR, GS, GOGAT, and GDH, and ammonia assimilation, but decrease nitrate and ammonia accumulation. In conclusion, La could relieve the damage effect of UV-B radiation on plant by regulating nitrogen metabolism process, and its alleviating effect under low level was better than that under the high one.

  9. A natural light/dark cycle regulation of carbon-nitrogen metabolism and gene expression in rice shoots

    Directory of Open Access Journals (Sweden)

    Haixing Li

    2016-08-01

    Full Text Available Light and temperature are two particularly important environmental cues for plant survival. Carbon and nitrogen are two essential macronutrients required for plant growth and development, and cellular carbon and nitrogen metabolism must be tightly coordinated. In order to understand how the natural light/dark cycle regulates carbon and nitrogen metabolism in rice plants, we analyzed the photosynthesis, key carbon-nitrogen metabolites and enzyme activities, and differentially expressed genes and miRNAs involved in the carbon and nitrogen metabolic pathway in rice shoots at the following times: 2:00, 6:00, 10:00, 14:00, 18:00 and 22:00. Our results indicated that more CO2 was fixed into carbohydrates by a high net photosynthetic rate, respiratory rate and stomatal conductance in the daytime. Although high levels of the nitrate reductase activity, free ammonium and carbohydrates were exhibited in the daytime, the protein synthesis was not significantly facilitated by the light and temperature. In mRNA sequencing, the carbon and nitrogen metabolism-related differentially expressed genes were obtained, which could be divided into eight groups: photosynthesis, TCA cycle, sugar transport, sugar metabolism, nitrogen transport, nitrogen reduction, amino acid metabolism and nitrogen regulation. Additionally, a total of 78,306 alternative splicing events have been identified, which primarily belong to alternative 5' donor sites, alternative 3' acceptor sites, intron retention and exon skipping. In sRNA sequencing, four carbon and nitrogen metabolism-related miRNAs (osa-miR1440b, osa-miR2876-5p, osa-miR1877 and osa-miR5799 were determined to be regulated by natural light/dark cycle. The expression level analysis showed that the four carbon and nitrogen metabolism-related miRNAs negatively regulated their target genes. These results may provide a good strategy to study how natural light/dark cycle regulates carbon and nitrogen metabolism to ensure plant

  10. Nitrogen

    Science.gov (United States)

    Apodaca, Lori E.

    2013-01-01

    The article presents an overview of the nitrogen chemical market as of July 2013, including the production of ammonia compounds. Industrial uses for ammonia include fertilizers, explosives, and plastics. Other topics include industrial capacity of U.S. ammonia producers CF Industries Holdings Inc., Koch Nitrogen Co., PCS Nitrogen, Inc., and Agrium Inc., the impact of natural gas prices on the nitrogen industry, and demand for corn crops for ethanol production.

  11. Anaerobic digestion of nitrogen rich poultry manure: Impact of thermophilic biogas process on metal release and microbial resistances.

    Science.gov (United States)

    Anjum, Reshma; Grohmann, Elisabeth; Krakat, Niclas

    2017-02-01

    Poultry manure is a nitrogen rich fertilizer, which is usually recycled and spread on agricultural fields. Due to its high nutrient content, chicken manure is considered to be one of the most valuable animal wastes as organic fertilizer. However, when chicken litter is applied in its native form, concerns are raised as such fertilizers also include high amounts of antibiotic resistant pathogenic Bacteria and heavy metals. We studied the impact of an anaerobic thermophilic digestion process on poultry manure. Particularly, microbial antibiotic resistance profiles, mobile genetic elements promoting the resistance dissemination in the environment as well as the presence of heavy metals were focused in this study. The initiated heat treatment fostered a community shift from pathogenic to less pathogenic bacterial groups. Phenotypic and molecular studies demonstrated a clear reduction of multiple resistant pathogens and self-transmissible plasmids in the heat treated manure. That treatment also induced a higher release of metals and macroelements. Especially, Zn and Cu exceeded toxic thresholds. Although the concentrations of a few metals reached toxic levels after the anaerobic thermophilic treatment, the quality of poultry manure as organic fertilizer may raise significantly due to the elimination of antibiotic resistance genes (ARG) and self-transmissible plasmids. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Scenedesmus-based treatment of nitrogen and phosphorus from effluent of anaerobic digester and bio-oil production.

    Science.gov (United States)

    Kim, Ga-Yeong; Yun, Yeo-Myeong; Shin, Hang-Sik; Kim, Hee-Sik; Han, Jong-In

    2015-11-01

    In this study, a microalgae-based technology was employed to treat wastewater and produce biodiesel at the same time. A local isolate Scenedesmus sp. was found to be a well suited species, particularly for an effluent from anaerobic digester (AD) containing low carbon but high nutrients (NH3-N=273mgL(-1), total P=58.75mgL(-1)). This algae-based treatment was quite effective: nutrient removal efficiencies were over 99.19% for nitrogen and 98.01% for phosphorus. Regarding the biodiesel production, FAME contents of Scenedesmus sp. were found to be relatively low (8.74% (w/w)), but overall FAME productivity was comparatively high (0.03gL(-1)d(-1)) due to its high biomass productivity (0.37gL(-1)d(-1)). FAMEs were satisfactory to the several standards for the biodiesel quality. The Scenedesmus-based technology may serve as a promising option for the treatment of nutrient-rich wastewater and especially so for the AD effluent. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Glutamine supplementation of parenteral nutrition does not improve intestinal permeability, nitrogen balance, or outcome in newborns and infants undergoing digestive-tract surgery: results from a double-blind, randomized, controlled trial

    NARCIS (Netherlands)

    E.W. Steyerberg (Ewout); F.W.J. Hazebroek (Frans); M. Mourik; G.J.J.M. Borsboom (Gerard); T. Rietveld (Trinet); J.G.M. Huijmans (Jan); D. Tibboel (Dick); M.J.I.J. Albers (Marcel)

    2005-01-01

    textabstractOBJECTIVE: To assess the effect of isocaloric isonitrogenous parenteral glutamine supplementation on intestinal permeability and nitrogen loss in newborns and infants after major digestive-tract surgery. SUMMARY BACKGROUND DATA: Glutamine supplementation in critically

  14. Nitrogen Addition Exacerbates the Negative Effects of Low Temperature Stress on Carbon and Nitrogen Metabolism in Moss

    Directory of Open Access Journals (Sweden)

    Bin-Yang Liu

    2017-08-01

    Full Text Available Global environmental changes are leading to an increase in localized abnormally low temperatures and increasing nitrogen (N deposition is a phenomenon recognized worldwide. Both low temperature stress (LTS and excess N induce oxidative stress in plants, and excess N also reduces their resistance to LTS. Mosses are primitive plants that are generally more sensitive to alterations in environmental factors than vascular species. To study the combined effects of N deposition and LTS on carbon (C and N metabolism in moss, two moss species, Pogonatum cirratum subsp. fuscatum, and Hypnum plumaeforme, exposed to various concentrations of nitrate (KNO3 or ammonium (NH4Cl, were treated with or without LTS. C/N metabolism indices were then monitored, both immediately after the stress and after a short recovery period (10 days. LTS decreased the photosystem II (PSII performance index and inhibited non-cyclic photophosphorylation, ribulose-1,5-bisphosphate carboxylase, and glutamine synthetase activities, indicating damage to PSII and reductions in C/N assimilation in these mosses. LTS did not affect cyclic photophosphorylation, sucrose synthase, sucrose-phosphate synthase, and NADP-isocitrate dehydrogenase activities, suggesting a certain level of energy and C skeleton generation were maintained in the mosses to combat LTS; however, LTS inhibited the activity of glycolate oxidase. As predicted, N supply increased the sensitivity of the mosses to LTS, resulting in greater damage to PSII and a sharper decrease in C/N assimilation. After the recovery period, the performance of PSII and C/N metabolism, which were inhibited by LTS increased significantly, and were generally higher than those of control samples not exposed to LTS, suggesting overcompensation effects; however, N application reduced the extent of compensation effects. Both C and N metabolism exhibited stronger compensation effects in H. plumaeforme than in P. cirratum subsp. fuscatum. The

  15. Characterizing bacterial gene expression in nitrogen cycle metabolism with RT-qPCR.

    Science.gov (United States)

    Graham, James E; Wantland, Nicholas B; Campbell, Mark; Klotz, Martin G

    2011-01-01

    Recent advances in DNA sequencing have greatly accelerated our ability to obtain the raw information needed to recognize both known and potential novel modular microbial genomic capacity for nitrogen metabolism. With PCR-based approaches to quantifying microbial mRNA expression now mainstream in most laboratories, researchers can now more efficiently propose and test hypotheses on the contributions of individual microbes to the biological accessibility of nitrogen upon which all other life depends. We review known microbial roles in these key nitrogen transformations, and describe the necessary steps in carrying out relevant gene expression studies. An example experimental design is then provided characterizing Nitrosococcus oceani mRNA expression in cultures responding to ammonia. The approach described, that of assessing microbial genome inventory and testing putative modular gene expression by mRNA quantification, is likely to remain an important tool in understanding individual microbial contributions within microbial community activities that maintain the Earth's nitrogen balance. Copyright © 2011 Elsevier Inc. All rights reserved.

  16. Metabolism of nitrogen-13 labelled ammonia in different conditions in dogs, human volunteers and transplant patients

    International Nuclear Information System (INIS)

    Bormans, G.; Maes, A.; Langendries, W.; Nuyts, J.; Vrolix, M.; Vanhaecke, J.; Schiepers, C.; Roo, M. de; Mortelmans, L.; Verbruggen, A.

    1995-01-01

    To investigate the rate of metabolism of nitrogen-13 labelled ammonia ( 13 NH 3 ) in different conditions, we have determined the relative amount of unchanged 13 NH 3 in the blood of dogs, volunteers and transplant patients at different times following injection. In dogs, the determinations were made under basal conditions, during adenosine administration and after coronary occlusion. The results show that adenosine administration increases the metabolic rate whereas coronary occlusion does not affect 13 NH 3 metabolism. For both human volunteers and transplant patients the metabolic rate of 13 NH 3 was assessed under basal conditions and during adenosine administration. 13 NH 3 metabolism proceeds faster in transplant patients than in volunteers under both conditions. Adenosine administration causes a faster 13 NH 3 turnover in volunteers but not in transplant patients. Application of individual metabolite correction resulted in a 16% decrease in the calculated blood flow compared to uncorrected values. A smaller difference (5%) was observed between correction with mean metabolite values and individually acquired metabolite values. (orig.)

  17. Regulation of Nitrogen Metabolism by GATA Zinc Finger Transcription Factors in Yarrowia lipolytica

    Energy Technology Data Exchange (ETDEWEB)

    Pomraning, Kyle R.; Bredeweg, Erin L.; Baker, Scott E.

    2017-02-15

    ABSTRACT

    Fungi accumulate lipids in a manner dependent on the quantity and quality of the nitrogen source on which they are growing. In the oleaginous yeastYarrowia lipolytica, growth on a complex source of nitrogen enables rapid growth and limited accumulation of neutral lipids, while growth on a simple nitrogen source promotes lipid accumulation in large lipid droplets. Here we examined the roles of nitrogen catabolite repression and its regulation by GATA zinc finger transcription factors on lipid metabolism inY. lipolytica. Deletion of the GATA transcription factor genesgzf3andgzf2resulted in nitrogen source-specific growth defects and greater accumulation of lipids when the cells were growing on a simple nitrogen source. Deletion ofgzf1, which is most similar to activators of genes repressed by nitrogen catabolite repression in filamentous ascomycetes, did not affect growth on the nitrogen sources tested. We examined gene expression of wild-type and GATA transcription factor mutants on simple and complex nitrogen sources and found that expression of enzymes involved in malate metabolism, beta-oxidation, and ammonia utilization are strongly upregulated on a simple nitrogen source. Deletion ofgzf3results in overexpression of genes with GATAA sites in their promoters, suggesting that it acts as a repressor, whilegzf2is required for expression of ammonia utilization genes but does not grossly affect the transcription level of genes predicted to be controlled by nitrogen catabolite repression. Both GATA transcription factor mutants exhibit decreased expression of genes controlled by carbon catabolite repression via the repressormig1, including genes for beta-oxidation, highlighting the complex interplay between regulation of carbon, nitrogen, and lipid metabolism.

    IMPORTANCENitrogen source is

  18. The Metabolic Conversion of Arginine in the Rumen Wall and its Importance in Ruminant Nitrogen Metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Harmeyer, J.; Kurelec, B.; Hill, H. [Department of Physiology, School of Veterinary Medicine, Hanover, Federal Republic of Germany (Germany)

    1968-07-01

    The functions of arginase and urease of the rumen wall were investigated in vitro and in vivo. Surviving ruminal mucosae of cattle were incubated for four hours. {sup 14}C-arginine-HCl, uniformly labelled, was added to the serosal side at a concentration of 10 pmol/mi. About 25% of the added arginine was used during the incubation by the ruminal tissue. In comparison with controls an increased amount of {sup 14}C-omithine, urea, and ammonia were formed in the mucosa and appeared on both sides. The increase was due to arginase and urease functions. It was estimated that about 50% of the urea formed by arginine breakdown were present at the mucosa side, mainly in the form of ammonia. Of the omithine simultaneously formed, 85% remained on the serosa side. Remarkable individual variations of omithine and urea formation were found from animal to animal. The in-vivo experiments were performed using goats with catheters placed in the right ruminal artery and vein. We injected 90 {mu}Ci of {sup 14}C-arginine into the ruminal artery. When 80 g of soluble starch were added to the rumen the activity and concentration of ornithine increased in the ruminal venous blood showing an arterial-venous difference. The radioactivity of urea in blood taken from the ruminal vein and the carotid artery did not show any difference. When starch was omitted from the rumen a comparable difference of omithine concentration was not found. It is assumed that the enzymes arginase and urease of the rumen wall are involved in nitrogen recycling processes. Blood arginine may be hydrolysed in the rumen wall forming urea and ornithine. Urea formed by arginine breakdown may be split to CO{sub 2} and ammonia. The experiments produced evidence that the ammonia formed preferably enters the rumen content. The nitrogen transfer through the rumen wall may be affected by varying activities of arginase. (author)

  19. Metabolic Remodeling of Membrane Glycerolipids in the Microalga Nannochloropsis oceanica under Nitrogen Deprivation

    Directory of Open Access Journals (Sweden)

    Danxiang Han

    2017-08-01

    Full Text Available HIGHLIGHTSAn electrospray ionization mass spectrometry-based lipidomics method was developed and integrated with transcriptomics to elucidate metabolic remodeling and turnover of microalgal membrane lipids by using Nannochloropsis oceanica as a model.The lack of lipidome analytical tools has limited our ability to gain new knowledge about lipid metabolism in microalgae, especially for membrane glycerolipids. An electrospray ionization mass spectrometry-based lipidomics method was developed for Nannochloropsis oceanica IMET1, which resolved 41 membrane glycerolipids molecular species belonging to eight classes. Changes in membrane glycerolipids under nitrogen deprivation and high-light (HL conditions were uncovered. The results showed that the amount of plastidial membrane lipids including monogalactosyldiacylglycerol, phosphatidylglycerol, and the extraplastidic lipids diacylglyceryl-O-4′-(N, N, N,-trimethyl homoserine and phosphatidylcholine decreased drastically under HL and nitrogen deprivation stresses. Algal cells accumulated considerably more digalactosyldiacylglycerol and sulfoquinovosyldiacylglycerols under stresses. The genes encoding enzymes responsible for biosynthesis, modification and degradation of glycerolipids were identified by mining a time-course global RNA-seq data set. It suggested that reduction in lipid contents under nitrogen deprivation is not attributable to the retarded biosynthesis processes, at least at the gene expression level, as most genes involved in their biosynthesis were unaffected by nitrogen supply, yet several genes were significantly up-regulated. Additionally, a conceptual eicosapentaenoic acid (EPA biosynthesis network is proposed based on the lipidomic and transcriptomic data, which underlined import of EPA from cytosolic glycerolipids to the plastid for synthesizing EPA-containing chloroplast membrane lipids.

  20. Key role of lipid management in nitrogen and aroma metabolism in an evolved wine yeast strain.

    Science.gov (United States)

    Rollero, Stéphanie; Mouret, Jean-Roch; Sanchez, Isabelle; Camarasa, Carole; Ortiz-Julien, Anne; Sablayrolles, Jean-Marie; Dequin, Sylvie

    2016-02-09

    Fermentative aromas play a key role in the organoleptic profile of young wines. Their production depends both on yeast strain and fermentation conditions. A present-day trend in the wine industry consists in developing new strains with aromatic properties using adaptive evolution approaches. An evolved strain, Affinity™ ECA5, overproducing esters, was recently obtained. In this study, dynamics of nitrogen consumption and of the fermentative aroma synthesis of the evolved and its ancestral strains were compared and coupled with a transcriptomic analysis approach to better understand the metabolic reshaping of Affinity™ ECA5. Nitrogen assimilation was different between the two strains, particularly amino acids transported by carriers regulated by nitrogen catabolite repression. We also observed differences in the kinetics of fermentative aroma production, especially in the bioconversion of higher alcohols into acetate esters. Finally, transcriptomic data showed that the enhanced bioconversion into acetate esters by the evolved strain was associated with the repression of genes involved in sterol biosynthesis rather than an enhanced expression of ATF1 and ATF2 (genes coding for the enzymes responsible for the synthesis of acetate esters from higher alcohols). An integrated approach to yeast metabolism-combining transcriptomic analyses and online monitoring data-showed differences between the two strains at different levels. Differences in nitrogen source consumption were observed suggesting modifications of NCR in the evolved strain. Moreover, the evolved strain showed a different way of managing the lipid source, which notably affected the production of acetate esters, likely because of a greater availability of acetyl-CoA for the evolved strain.

  1. IDMS of FeO(OH) extracted from blood digests for studies of iron metabolism in humans

    International Nuclear Information System (INIS)

    Vieira, N.E.; Yergey

    1996-01-01

    The following isolation procedures were used for the determination of iron in water and digested whole blood matrices in connection with isotope dilution mass spectrometry (IDMS) of iron in blood for metabolic studies: precipitation as hydroxide, ion exchange chromatography using membrane filters, and evaporation of the untreated matrix followed by extraction of the residue with dilute acid. Although recovery is better with the cation exchange techniques, overall precision of IDMS analysis favours direct precipitation, which is also simpler and quicker. 3 refs., 3 tabs

  2. Long-term trends of changes in pine and oak foliar nitrogen metabolism in response to chronic nitrogen amendments at Harvard Forest, MA

    Science.gov (United States)

    Rakesh Minocha; Swathi A. Turlapati; Stephanie Long; William H. McDowell; Subhash C. Minocha

    2015-01-01

    We evaluated the long-term (1995-2008) trends in foliar and sapwood metabolism, soil solution chemistry and tree mortality rates in response to chronic nitrogen (N) additions to pine and hardwood stands at the Harvard Forest Long Term Ecological Research (LTER) site. Common stress-related metabolites like polyamines (PAs), free amino acids (AAs) and inorganic elements...

  3. Effects of ruminally degradable starch levels on performance, nitrogen balance, and nutrient digestibility in dairy cows fed low corn-based starch diets

    Directory of Open Access Journals (Sweden)

    Guobin Luo

    2017-05-01

    Full Text Available Objective This trial was performed to examine the effects of ruminally degradable starch (RDS levels in total mixed ration (TMR with low corn-based starch on the milk production, whole-tract nutrient digestibility and nitrogen balance in dairy cows. Methods Eight multiparous Holstein cows (body weight [BW]: 717±63 kg; days in milk [DIM]: 169±29 were assigned to a crossover design with two dietary treatments: a diet containing 62.3% ruminally degradable starch (% of total starch, low RDS or 72.1% ruminally degradable starch (% of total starch, high RDS. Changes to the ruminally degradable levels were conducted by using either finely ground corn or steam-flaked corn as the starch component. Results The results showed that dry matter intake, milk yield and composition in dairy cows were not affected by dietary treatments. The concentration of milk urea nitrogen was lower for cows fed high RDS TMR than low RDS TMR. The whole-tract apparent digestibility of neutral detergent fiber, acid detergent fiber and crude protein decreased, and that of starch increased for cows fed high RDS TMR over those fed low RDS TMR, with no dietary effect on the whole-tract apparent digestibility of dry matter and organic matter. The proportion of urinary N excretion in N intake was lower and that of fecal N excretion in N intake was higher for cows fed high RDS TMR than those fed low RDS TMR. The N secretion in milk and the retention of N were not influenced by the dietary treatments. Total purine derivative was similar in cows fed high RDS TMR and low RDS TMR. Consequently, estimated microbial N flow to the duodenum was similar in cows fed high RDS TMR and low RDS TMR. Conclusion Results of this study show that ruminally degradable starch levels can influence whole-tract nutrient digestibility and nitrogen balance in dairy cows fed low corn-based starch diets, with no influence on performance.

  4. Maize source leaf adaptation to nitrogen deficiency affects not only nitrogen and carbon metabolism but also control of phosphate homeostasis.

    Science.gov (United States)

    Schlüter, Urte; Mascher, Martin; Colmsee, Christian; Scholz, Uwe; Bräutigam, Andrea; Fahnenstich, Holger; Sonnewald, Uwe

    2012-11-01

    Crop plant development is strongly dependent on the availability of nitrogen (N) in the soil and the efficiency of N utilization for biomass production and yield. However, knowledge about molecular responses to N deprivation derives mainly from the study of model species. In this article, the metabolic adaptation of source leaves to low N was analyzed in maize (Zea mays) seedlings by parallel measurements of transcriptome and metabolome profiling. Inbred lines A188 and B73 were cultivated under sufficient (15 mM) or limiting (0.15 mM) nitrate supply for up to 30 d. Limited availability of N caused strong shifts in the metabolite profile of leaves. The transcriptome was less affected by the N stress but showed strong genotype- and age-dependent patterns. N starvation initiated the selective down-regulation of processes involved in nitrate reduction and amino acid assimilation; ammonium assimilation-related transcripts, on the other hand, were not influenced. Carbon assimilation-related transcripts were characterized by high transcriptional coordination and general down-regulation under low-N conditions. N deprivation caused a slight accumulation of starch but also directed increased amounts of carbohydrates into the cell wall and secondary metabolites. The decrease in N availability also resulted in accumulation of phosphate and strong down-regulation of genes usually involved in phosphate starvation response, underlining the great importance of phosphate homeostasis control under stress conditions.

  5. Hemicellulose conversion by anaerobic digestion

    Energy Technology Data Exchange (ETDEWEB)

    Ghosh, S; Honry, M P; Christopher, R W

    1985-01-01

    This research was undertaken to study the digestibility of the hemicellulose fractions of an aquatic biomass, a land-based biomass and a biomass-waste blend under various fermentation conditions. The conversion of hemicellulose was higher than those of cellulose and protein under the mesophilic condition. Hemicellulose was converted at a much lower efficency than cellulose during thermophilic digestion. In contrast, cellulose conversion was about the same under mesophilic and thermophilic conditions. Cellulose was utilized in preference to hemicellulose during mesophilic fermentation of nitrogen-supplemented Bermuda grass. It was speculated that Bermuda grass cellulose was converted at a higher efficiency than hemicellulose in the pressure of external nitrogen because the metabolism of the breakdown product (glucose) of cellulose required the least investment of enzymes and energy. 4 references.

  6. METABOLIC ENGINEERING TO DEVELOP A PATHWAY FOR THE SELECTIVE CLEAVAGE OF CARBON-NITROGEN BONDS

    Energy Technology Data Exchange (ETDEWEB)

    John J. Kilbane II

    2004-10-01

    The objective of the project is to develop biochemical pathways for the selective cleavage of C-N bonds in molecules found in petroleum. The initial phase of the project was focused on the isolation or development of an enzyme capable of cleaving the C-N bond in aromatic amides, specifically 2-aminobiphenyl. The objective of the second phase of the research will be to construct a biochemical pathway for the selective removal of nitrogen from carbazole by combining the carA genes from Sphingomonas sp. GTIN11 with the gene(s) encoding an appropriate deaminase. The objective of the final phase of the project will be to develop derivative C-N bond cleaving enzymes that have broader substrate ranges and to demonstrate the use of such strains to selectively remove nitrogen from petroleum. During the first year of the project (October, 2002-September, 2003) enrichment culture experiments resulted in the isolation of microbial cultures that utilize aromatic amides as sole nitrogen sources, several amidase genes were cloned and were included in directed evolution experiments to obtain derivatives that can cleave C-N bonds in aromatic amides, and the carA genes from Sphingomonas sp. GTIN11, and Pseudomonas resinovorans CA10 were cloned in vectors capable of replicating in Escherichia coli. During the second year of the project (October, 2003-September, 2004) enrichment culture experiments succeeded in isolating a mixed bacterial culture that can utilize 2-aminobiphenyl as a sole nitrogen source, directed evolution experiments were focused on the aniline dioxygenase enzyme that is capable of deaminating aniline, and expression vectors were constructed to enable the expression of genes encoding C-N bond cleaving enzymes in Rhodococcus hosts. The construction of a new metabolic pathway to selectively remove nitrogen from carbazole and other molecules typically found in petroleum should lead to the development of a process to improve oil refinery efficiency by reducing the

  7. Stability and metabolism of Arbutus unedo bioactive compounds (phenolics and antioxidants) under in vitro digestion and colonic fermentation.

    Science.gov (United States)

    Mosele, Juana I; Macià, Alba; Romero, Mari-Paz; Motilva, María-José

    2016-06-15

    The natural antioxidants of Arbutus unedo highlight the importance of this fruit as natural source of bioactive compounds. In the present study, to evaluate the stability of phenolic compounds, ascorbic acid and fat-soluble antioxidants (α-tocopherol, β-carotene and lutein), in vitro gastrointestinal digestion was applied to A. unedo fruit. After that, the non-absorbable fraction was anaerobically incubated with human faeces and the metabolic pathway for gallotannins, ellagitannins, flavan-3-ols and anthocyanins from A. unedo fruit was proposed. The results showed that the presence of pectin from the fruit hampered the solubilization of the phenolic compounds (with exception of gallic and ellagic acids) and fat-soluble vitamins during gastric digestion. Degradation of pectin-gel during the duodenal digestion favored the release of the phenolic compounds and fat-soluble antioxidants to the media. The catabolic activity of human microbiota led to the generation of a wide range of simple phenols, such as p-hydroxybenzoic acid and catechol, derived from the catabolism of gallotannins, ellagitannins, flavan-3-ols and anthocyanins. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Effects of dietary amylose/amylopectin ratio on growth performance, feed utilization, digestive enzymes, and postprandial metabolic responses in juvenile obscure puffer Takifugu obscurus.

    Science.gov (United States)

    Liu, Xiang-he; Ye, Chao-xia; Ye, Ji-dan; Shen, Bi-duan; Wang, Chun-yan; Wang, An-li

    2014-10-01

    The effect of dietary amylose/amylopectin (AM/AP) ratio on growth, feed utilization, digestive enzyme activities, plasma parameters, and postprandial blood glucose responses was evaluated in juvenile obscure puffer, Takifugu obscurus. Five isonitrogenous (430 g kg(-1) crude protein) and isolipidic (90 g kg(-1) crude lipid) diets containing an equal starch level (250 g kg(-1) starch) with different AM/AP ratio diets of 0/25, 3/22, 6/19, 9/16 and 12/13 were formulated. Each experimental diet was fed to triplicate groups (25 fish per tank), twice daily during a period of 60 days. After the growth trial, a postprandial blood response test was carried out. Fish fed diet 6/19 showed best growth, feed efficiency and protein efficiency ratio. Hepatosomatic index, plasma total cholesterol concentration, liver glycogen and lipid content, and gluconokinase, pyruvate kinase and fructose-1,6-bisphosphatase activities were lower in fish fed highest AM/AP diet (12/13) than in fish fed the low-amylose diets. Activities of liver and intestinal trypsin in fish fed diet 3/22 and diet 6/19 were higher than in fish fed diet 9/16 and diet 12/13. Activities of liver and intestinal amylase and intestinal lipase, and starch digestibility were negatively correlated with dietary AM/AP ratio. Fish fed diet 3/22 and diet 6/19 showed higher plasma total amino acid concentration than fish fed the other diets, while plasma urea nitrogen concentration and activities of alanine aminotransferase and aspartate aminotransferase showed the opposite trend. Equal values were found for viscerosomatic index and condition factor, whole body and muscle composition, plasma high-density and low-density lipoprotein cholesterol concentrations, and activities of lipase and hexokinase and glucose-6-phosphatase in liver. Postprandial plasma glucose and triglyceride peak value of fish fed diet 12/13 were lower than in fish fed the low-amylose diets, and the peak time of plasma glucose was later than in fish fed the

  9. Expressed sequence tags related to nitrogen metabolism in maize inoculated with Azospirillum brasilense.

    Science.gov (United States)

    Pereira-Defilippi, L; Pereira, E M; Silva, F M; Moro, G V

    2017-05-31

    The relative quantitative real-time expression of two expressed sequence tags (ESTs) codifying for key enzymes in nitrogen metabolism in maize, nitrate reductase (ZmNR), and glutamine synthetase (ZmGln1-3) was performed for genotypes inoculated with Azospirillum brasilense. Two commercial single-cross hybrids (AG7098 and 2B707) and two experimental synthetic varieties (V2 and V4) were raised under controlled greenhouse conditions, in six treatment groups corresponding to different forms of inoculation and different levels of nitrogen application by top-dressing. The genotypes presented distinct responses to inoculation with A. brasilense. Increases in the expression of ZmNR were observed for the hybrids, while V4 only displayed a greater level of expression when the plants received nitrogenous fertilization by top-dressing and there was no inoculation. The expression of the ZmGln1-3EST was induced by A. brasilense in the hybrids and the variety V4. In contrast, the variety V2 did not respond to inoculation.

  10. Growth versus metabolic tissue replacement in mouse tissues determined by stable carbon and nitrogen isotope analysis

    Science.gov (United States)

    Macavoy, S. E.; Jamil, T.; Macko, S. A.; Arneson, L. S.

    2003-12-01

    Stable isotope analysis is becoming an extensively used tool in animal ecology. The isotopes most commonly used for analysis in terrestrial systems are those of carbon and nitrogen, due to differential carbon fractionation in C3 and C4 plants, and the approximately 3‰ enrichment in 15N per trophic level. Although isotope signatures in animal tissues presumably reflect the local food web, analysis is often complicated by differential nutrient routing and fractionation by tissues, and by the possibility that large organisms are not in isotopic equilibrium with the foods available in their immediate environment. Additionally, the rate at which organisms incorporate the isotope signature of a food through both growth and metabolic tissue replacement is largely unknown. In this study we have assessed the rate of carbon and nitrogen isotopic turnover in liver, muscle and blood in mice following a diet change. By determining growth rates, we were able to determine the proportion of tissue turnover caused by growth versus that caused by metabolic tissue replacement. Growth was found to account for approximately 10% of observed tissue turnover in sexually mature mice (Mus musculus). Blood carbon was found to have the shortest half-life (16.9 days), followed by muscle (24.7 days). Liver carbon turnover was not as well described by the exponential decay equations as other tissues. However, substantial liver carbon turnover was observed by the 28th day after diet switch. Surprisingly, these tissues primarily reflect the carbon signature of the protein, rather than carbohydrate, source in their diet. The nitrogen signature in all tissues was enriched by 3 - 5‰ over their dietary protein source, depending on tissue type, and the isotopic turnover rates were comparable to those observed in carbon.

  11. Evaluation of between-cow variation in milk urea and rumen ammonia nitrogen concentrations and the association with nitrogen utilization and diet digestibility in lactating cows.

    Science.gov (United States)

    Huhtanen, P; Cabezas-Garcia, E H; Krizsan, S J; Shingfield, K J

    2015-05-01

    Concentrations of milk urea N (MUN) are influenced by dietary crude protein concentration and intake and could therefore be used as a biomarker of the efficiency of N utilization for milk production (milk N/N intake; MNE) in lactating cows. In the present investigation, data from milk-production trials (production data set; n=1,804 cow/period observations from 21 change-over studies) and metabolic studies involving measurements of nutrient flow at the omasum in lactating cows (flow data set; n=450 cow/period observations from 29 studies) were used to evaluate the influence of between-cow variation on the relationship of MUN with MNE, urinary N (UN) output, and diet digestibility. All measurements were made on cows fed diets based on grass silage supplemented with a range of protein supplements. Data were analyzed by mixed-model regression analysis with diet within experiment and period within experiment as random effects, allowing the effect of diet and period to be excluded. Between-cow coefficient of variation in MUN concentration and MNE was 0.13 and 0.07 in the production data set and 0.11 and 0.08 in the flow data set, respectively. Based on residual variance, the best model for predicting MNE developed from the production data set was MNE (g/kg)=238 + 7.0 × milk yield (MY; kg/d) - 0.064 × MY(2) - 2.7 × MUN (mg/dL) - 0.10 body weight (kg). For the flow data set, including both MUN and rumen ammonia N concentration with MY in the model accounted for more variation in MNE than when either term was used with MY alone. The best model for predicting UN excretion developed from the production data set (n=443) was UN (g/d)=-29 + 4.3 × dry matter intake (kg/d) + 4.3 × MUN + 0.14 × body weight. Between-cow variation had a smaller influence on the association of MUN with MNE and UN output than published estimates of these relationships based on treatment means, in which differences in MUN generally arise from variation in dietary crude protein concentration. For

  12. Effects of dietary combination of corn and rice as whole crop silage and grain sources on carbohydrate digestion and nitrogen use in steers.

    Science.gov (United States)

    Li, Zongfu; Sugino, Toshihisa; Obitsu, Taketo; Taniguchi, Kohzo

    2014-02-01

    Four Holstein steers were used to evaluate the combination effects of whole crop corn (Cs) or rice (Rs) silage with steam-flaked corn (Cg) or rice (Rg) grain (four dietary treatments) on ruminal carbohydrate digestion, duodenal nitrogen (N) flow and plasma essential amino acid (EAA) concentration. The ruminal digestibility of starch and nonfiber carbohydrate (NFC) for Rs and Rg diets compared with Cs and Cg diets was greater, but that of neutral detergent fiber (aNDFom) was less. Because the ruminal disappearance of NFC plus aNDFom was similar across four dietary treatments, microbial N flow was not affected by the diets. There was an interaction of methionine (Met) flow by silage and grain sources: greatest for CsRg and least for RsRg diet, and blood plasma concentration of Met after feeding was lower for Rg than Cg diets. Postprandial reduction degree of plasma EAA varied with the diets and individual EAA. The Cs diets compared with the Rs diets tended to be greater in N retention because of greater digestible organic matter (OM) intake. These results suggest that silage source combined with corn or rice grain affects N use in steers through the digestible OM intake, and the kinds of limiting AA may differ among the combination of silage and grain sources. © 2013 Japanese Society of Animal Science.

  13. Studies on the nitrogen metabolism of the large intestine of ruminants. 2

    International Nuclear Information System (INIS)

    Sommer, A.; Ceresnakova, Z.; Szakacs, J.; Chrastinova, L.; Bergner, H.; Simon, O.

    1986-01-01

    3 bulls with body weights of 201, 168 and 190 kg, were equipped with a ileo-cecal re-entrant cannula and with catheters in the jugular veins on both sides. The pelleted ration was composed of straw 70-72%, cereals 10%, molasses 12-41% ammoniumhydrogencarbonate 3%, urea 2% and mineral mixture 1%. During a preliminary period ileal digesta were collected, deep-freezed and stored. During the main experiment 15 N-urea was infused intravenously for 24 hours. In this period and during the following 6 hours outflowing ileal digesta were collected quantitatively. At the same time precollected, unlabelled digesta together with a supplement of partly hydrolyzed straw meal were reintroduced into the cecal part of the cannula. Plasma urea N, urinary N as well as several N fractions of feces and digesta were analyzed for 15 N abundance. A urea flux rate of 27.9 +- 3.4 μmol per minute per kg/sup 0.75/ was estimated. It was calculated that 52% of this amount of urea was transfered into the digestive tract. In both, digesta and feces NH 3 nitrogen was highest 15 N-labelled indicating a direct urea entry and degradation in both segments of the digestive tract. The amounts of 15 N excess found during the period of digesta replacement were in feces 0.25 and in ileal digesta 4.02% of the infused 15 N. Although the microbial utilization of endogenous urea N was generally low in the large intestine there was a clear stimulation of this process due to the additional supply of the large intestine with a fermentable source. (author)

  14. Studies on supplementary desalted mother liquor on digestibility of nutrients, ruminal fermentation, and energy and nitrogen balance in Thai native cattle.

    Science.gov (United States)

    Sakai, Takashi; Angthong, Wanna; Takeda, Motoharu; Oishi, Kazato; Hirooka, Hiroyuki; Kumagai, Hajime

    2017-09-01

    Four Thai native steers were used to determine the adequate levels of supplementary desalted mother liquor (DML) for energy and nitrogen balances and ruminal fermentation. The crude protein and sodium chloride contents of DML were 25.5% and 60.3% on a dry matter (DM) basis, respectively. A 4 × 4 Latin square design experiment was conducted by adding different amounts of DML to three experimental diets (T1: 1.1%, T2: 2.2%, T3: 3.4% sodium chloride concentration with supplementary DML on a DM basis) and comparing their effects with those of a control diet (C) containing 1.0% commercial salt on a DM basis. The animals were given the experimental diets and rice straw daily at 1.2% and 0.8% of body weight, respectively, on a DM basis. No significant differences in the apparent digestibility of nutrients were observed among treatments. T3 achieved the lowest nitrogen retention (P < 0.05), followed by C, T2 and T1. The ratios of energy retention to gross energy were higher in T1 and T3 than T2, and that in C was lowest (P < 0.05). Supplementary NaCl concentration at 1% and 2% can be replaced with DML without an adverse effect on the digestibility of nutrients or on the nitrogen and energy retention. © 2017 Japanese Society of Animal Science.

  15. Effects of CO2 enrichment on photosynthesis, growth, and nitrogen metabolism of the seagrass Zostera noltii

    Science.gov (United States)

    Alexandre, Ana; Silva, João; Buapet, Pimchanok; Björk, Mats; Santos, Rui

    2012-01-01

    Seagrass ecosystems are expected to benefit from the global increase in CO2 in the ocean because the photosynthetic rate of these plants may be Ci-limited at the current CO2 level. As well, it is expected that lower external pH will facilitate the nitrate uptake of seagrasses if nitrate is cotransported with H+ across the membrane as in terrestrial plants. Here, we investigate the effects of CO2 enrichment on both carbon and nitrogen metabolism of the seagrass Zostera noltii in a mesocosm experiment where plants were exposed for 5 months to two experimental CO2 concentrations (360 and 700 ppm). Both the maximum photosynthetic rate (Pm) and photosynthetic efficiency (α) were higher (1.3- and 4.1-fold, respectively) in plants exposed to CO2-enriched conditions. On the other hand, no significant effects of CO2 enrichment on leaf growth rates were observed, probably due to nitrogen limitation as revealed by the low nitrogen content of leaves. The leaf ammonium uptake rate and glutamine synthetase activity were not significantly affected by increased CO2 concentrations. On the other hand, the leaf nitrate uptake rate of plants exposed to CO2-enriched conditions was fourfold lower than the uptake of plants exposed to current CO2 level, suggesting that in the seagrass Z. noltii nitrate is not cotransported with H+ as in terrestrial plants. In contrast, the activity of nitrate reductase was threefold higher in plant leaves grown at high-CO2 concentrations. Our results suggest that the global effects of CO2 on seagrass production may be spatially heterogeneous and depend on the specific nitrogen availability of each system. Under a CO2 increase scenario, the natural levels of nutrients will probably become limiting for Z. noltii. This potential limitation becomes more relevant because the expected positive effect of CO2 increase on nitrate uptake rate was not confirmed. PMID:23145346

  16. Effects of CO(2) enrichment on photosynthesis, growth, and nitrogen metabolism of the seagrass Zostera noltii.

    Science.gov (United States)

    Alexandre, Ana; Silva, João; Buapet, Pimchanok; Björk, Mats; Santos, Rui

    2012-10-01

    Seagrass ecosystems are expected to benefit from the global increase in CO(2) in the ocean because the photosynthetic rate of these plants may be C(i)-limited at the current CO(2) level. As well, it is expected that lower external pH will facilitate the nitrate uptake of seagrasses if nitrate is cotransported with H(+) across the membrane as in terrestrial plants. Here, we investigate the effects of CO(2) enrichment on both carbon and nitrogen metabolism of the seagrass Zostera noltii in a mesocosm experiment where plants were exposed for 5 months to two experimental CO(2) concentrations (360 and 700 ppm). Both the maximum photosynthetic rate (P(m)) and photosynthetic efficiency (α) were higher (1.3- and 4.1-fold, respectively) in plants exposed to CO(2)-enriched conditions. On the other hand, no significant effects of CO(2) enrichment on leaf growth rates were observed, probably due to nitrogen limitation as revealed by the low nitrogen content of leaves. The leaf ammonium uptake rate and glutamine synthetase activity were not significantly affected by increased CO(2) concentrations. On the other hand, the leaf nitrate uptake rate of plants exposed to CO(2)-enriched conditions was fourfold lower than the uptake of plants exposed to current CO(2) level, suggesting that in the seagrass Z. noltii nitrate is not cotransported with H(+) as in terrestrial plants. In contrast, the activity of nitrate reductase was threefold higher in plant leaves grown at high-CO(2) concentrations. Our results suggest that the global effects of CO(2) on seagrass production may be spatially heterogeneous and depend on the specific nitrogen availability of each system. Under a CO(2) increase scenario, the natural levels of nutrients will probably become limiting for Z. noltii. This potential limitation becomes more relevant because the expected positive effect of CO(2) increase on nitrate uptake rate was not confirmed.

  17. EFFECTIVENESS OF NITROGEN-CONTAINING BISPHOSPHONATES IN THE REGULATION OF MINERAL METABOLISM DISTURBANCES ASSOCIATED WITH ALIMENTARY OSTEOPOROSIS IN RATS

    OpenAIRE

    Komisarenko S. V.; Volochnyuk D. M.; Shymanskyy I. O.; Ivonin S. P.; Veliky M. M.1

    2015-01-01

    The aim of the study was to investigate the effectiveness of nitrogen-containing bisphosphonates synthesized as promising substances for correction of mineral metabolism in osteoporosis. The study was carried out on a model of alimentary osteoporosis that was characterized by hypocalcaemia, hypophosphatemia, decreased 25-Hydroxyvitamin D3 content in blood serum and severe bone tissue demineralization (reduced ash content and mineral components). It was found that synthesized novel nitrogen bi...

  18. Volatile fatty acids (VFAs) production from swine manure through short-term dry anaerobic digestion and its separation from nitrogen and phosphorus resources in the digestate.

    Science.gov (United States)

    Huang, Weiwei; Huang, Wenli; Yuan, Tian; Zhao, Ziwen; Cai, Wei; Zhang, Zhenya; Lei, Zhongfang; Feng, Chuanping

    2016-03-01

    The sustainability of an agricultural system depends highly upon the recycling of all useful substances from agricultural wastes. This study explored the feasibility of comprehensive utilization of C, N and P resources in swine manure (SM) through short-term dry anaerobic digestion (AD) followed by dry ammonia stripping, aiming at achieving (1) effective total volatile fatty acids (VFAs) production and separation; (2) ammonia recovery from the digestate; and (3) preservation of high P bioavailability in the solid residue for further applications. Specifically, two ammonia stripping strategies were applied and compared in this work: (I) ammonia stripping was directly performed with the digestate from dry AD of SM (i.e. dry ammonia stripping); and (II) wet ammonia stripping was conducted by using the resultant filtrate from solid-liquid separation of the mixture of digestate and added water. Results showed that dry AD of the tested SM at 55 °C, 20% TS and unadjusted initial pH (8.6) for 8 days produced relatively high concentrations of total VFAs (94.4 mg-COD/g-VS) and ammonia-N (20.0 mg/g-VS) with high potentially bioavailable P (10.6 mg/g-TS) remained in the digestate, which was considered optimal in this study. In addition, high ammonia removal efficiencies of 96.2% and 99.7% were achieved through 3 h' dry and wet stripping (at 55 °C and initial pH 11.0), respectively, while the total VFAs concentration in the digestate/filtrate remained favorably unchanged. All experimental data from the two stripping processes well fitted to the pseudo first-order kinetic model (R(2) = 0.9916-0.9997) with comparable theoretical maximum ammonia removal efficiencies (Aeq, >90%) being obtained under the tested dry and wet stripping conditions, implying that the former was more advantageous due to its much higher volumetric total ammonia-N removal rate thus much smaller reactor volume, less energy/chemicals consumption and no foaming problems. After 8 days' dry AD and 3

  19. Metatranscriptomics reveal differences in in situ energy and nitrogen metabolism among hydrothermal vent snail symbionts.

    Science.gov (United States)

    Sanders, J G; Beinart, R A; Stewart, F J; Delong, E F; Girguis, P R

    2013-08-01

    Despite the ubiquity of chemoautotrophic symbioses at hydrothermal vents, our understanding of the influence of environmental chemistry on symbiont metabolism is limited. Transcriptomic analyses are useful for linking physiological poise to environmental conditions, but recovering samples from the deep sea is challenging, as the long recovery times can change expression profiles before preservation. Here, we present a novel, in situ RNA sampling and preservation device, which we used to compare the symbiont metatranscriptomes associated with Alviniconcha, a genus of vent snail, in which specific host-symbiont combinations are predictably distributed across a regional geochemical gradient. Metatranscriptomes of these symbionts reveal key differences in energy and nitrogen metabolism relating to both environmental chemistry (that is, the relative expression of genes) and symbiont phylogeny (that is, the specific pathways employed). Unexpectedly, dramatic differences in expression of transposases and flagellar genes suggest that different symbiont types may also have distinct life histories. These data further our understanding of these symbionts' metabolic capabilities and their expression in situ, and suggest an important role for symbionts in mediating their hosts' interaction with regional-scale differences in geochemistry.

  20. Effect of Simulated Heat Stress on Digestibility, Methane Emission and Metabolic Adaptability in Crossbred Cattle

    Directory of Open Access Journals (Sweden)

    Brijesh Yadav

    2016-11-01

    Full Text Available The present experiment was conducted to evaluate the effect of simulated heat stress on digestibility and methane (CH4 emission. Four non-lactating crossbred cattle were exposed to 25°C, 30°C, 35°C, and 40°C temperature with a relative humidity of 40% to 50% in a climatic chamber from 10:00 hours to 15:00 hours every day for 27 days. The physiological responses were recorded at 15:00 hours every day. The blood samples were collected at 15:00 hours on 1st, 6th, 11th, 16th, and 21st days and serum was collected for biochemical analysis. After 21 days, fecal and feed samples were collected continuously for six days for the estimation of digestibility. In the last 48 hours gas samples were collected continuously to estimate CH4 emission. Heat stress in experimental animals at 35°C and 40°C was evident from an alteration (p<0.05 in rectal temperature, respiratory rate, pulse rate, water intake and serum thyroxin levels. The serum lactate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase activity and protein, urea, creatinine and triglyceride concentration changed (p<0.05, and body weight of the animals decreased (p<0.05 after temperature exposure at 40°C. The dry matter intake (DMI was lower (p<0.05 at 40°C exposure. The dry matter and neutral detergent fibre digestibilities were higher (p<0.05 at 35°C compared to 25°C and 30°C exposure whereas, organic matter (OM and acid detergent fibre digestibilities were higher (p<0.05 at 35°C than 40°C thermal exposure. The CH4 emission/kg DMI and organic matter intake (OMI declined (p<0.05 with increase in exposure temperature and reached its lowest levels at 40°C. It can be concluded from the present study that the digestibility and CH4 emission were affected by intensity of heat stress. Further studies are necessary with respect to ruminal microbial changes to justify the variation in the digestibility and CH4 emission during differential heat stress.

  1. Fuels derived from starch digestion have different effects on energy intake and metabolic responses of cows in the postpartum period.

    Science.gov (United States)

    Gualdrón-Duarte, Laura B; Allen, Michael S

    2018-03-07

    Absorbed fuels from the digestion of starch include propionic acid (PA) produced by ruminal fermentation and glucose (GLU) from intestinal digestion, which may be partially metabolized to lactic acid (LA) by intestinal tissues. Our objective was to evaluate the effects of these fuels on dry matter intake (DMI) and feeding behavior of cows in the postpartum period. We hypothesized that these fuels affect feed intake differently and that their effects are related to differences in their hepatic metabolism. Glucose was expected to have little effect on feed intake because little or no GLU is extracted from the blood by the liver. Whereas both LA and PA are anaplerotic and can stimulate oxidation of acetyl CoA in hepatocytes, hepatic extraction of PA is greater than LA, which depends on cytosolic redox state. Continuous isoenergetic infusions (150 kcal of ME/h) of PA, LA, or GLU or no infusion were administered abomasally to 8 ruminally cannulated multiparous Holstein cows (12.4 ± 6.2 d postpartum) in a duplicate 4 × 4 Latin square design experiment, with four 1-d infusion periods, balanced for carry-over effects. Treatment sequences were assigned to cows randomly, and treatments included control (CON, no infusion), PA (0.41 mol/h), LA (0.46 mol/h), and GLU (0.22 mol/h). Solutions containing treatments were infused at 500 mL/h for 22 h/d and provided ~3.3 Mcal/d. Feeding behavior was recorded by a computerized data acquisition system. Gross energy digestibility of the diet was determined for each cow and used to calculate metabolizable energy intake (MEI) from the diet. Total MEI was calculated as the sum of MEI from the diet plus energy from infusions. Data were analyzed statistically with a mixed model including the fixed effect of treatment and random effects of block and cow within block. Each treatment was compared with CON by contrasts. Compared with CON, PA decreased DMI by 24% (14.3 vs. 18.9 kg/d) and total MEI by 13% (34.8 vs. 40.2 Mcal/d) with a tendency to

  2. Improvement of nitrogen accumulation and metabolism in rice (Oryza sativa L.) by the endophyte Phomopsis liquidambari.

    Science.gov (United States)

    Yang, Bo; Ma, Hai-Yan; Wang, Xiao-Mi; Jia, Yong; Hu, Jing; Li, Xia; Dai, Chuan-Chao

    2014-09-01

    The fungal endophyte Phomopsis liquidambari can enhance nitrogen (N) uptake and metabolism of rice plants under hydroponic conditions. To investigate the effects of P. liquidambari on N accumulation and metabolism in rice (Oryza sativa L.) under field conditions during the entire growing season (S1, the seedling stage; S2, the tillering stage; S3, the heading stage; S4, the ripening stage), we utilized pot experiments to examine metabolic and physiological levels in both shoot and root tissues of rice, with endophyte (E+) and without endophyte (E-), in response to three different N levels. We found that under low-N treatment, P. liquidambari symbiosis increased the rice yield and N use efficiency by 12% and by 11.59%, respectively; that the total N contents in E+ rice plants at the four growth stages were separately increased by 29.05%, 14.65%, 21.06% and 18.38%, respectively; and that the activities of nitrate reductase and glutamine synthetase in E+ rice roots and shoots were significantly increased by fungal infection during the S1 to S3 stages. Moreover, P. liquidambari significantly increased the free NH4(+), NO3(-), amino acid and soluble protein contents in infected rice tissues under low-N treatment during the S1 to S3 stages. The obtained results offer novel data concerning the systemic changes induced by P. liquidambari in rice during the entire growth period and confirm the hypothesis that the rice-P. liquidambari interaction improved the N accumulation and metabolism of rice plants, consequently increasing rice N utilization in nutrient-limited soil. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  3. Modeling the role of covalent enzyme modification in Escherichia coli nitrogen metabolism

    International Nuclear Information System (INIS)

    Kidd, Philip B; Wingreen, Ned S

    2010-01-01

    In the bacterium Escherichia coli, the enzyme glutamine synthetase (GS) converts ammonium into the amino acid glutamine. GS is principally active when the cell is experiencing nitrogen limitation, and its activity is regulated by a bicyclic covalent modification cascade. The advantages of this bicyclic-cascade architecture are poorly understood. We analyze a simple model of the GS cascade in comparison to other regulatory schemes and conclude that the bicyclic cascade is suboptimal for maintaining metabolic homeostasis of the free glutamine pool. Instead, we argue that the lag inherent in the covalent modification of GS slows the response to an ammonium shock and thereby allows GS to transiently detoxify the cell, while maintaining homeostasis over longer times

  4. Effects of UV-B and heavy metals on nitrogen and phosphorus metabolism in three cyanobacteria.

    Science.gov (United States)

    Yadav, Shivam; Prajapati, Rajesh; Atri, Neelam

    2016-01-01

    Cyanobacteria sp. (diazotrophic and planktonic) hold a major position in ecosystem, former one due to their intrinsic capability of N2-fixation and later because of mineralization of organic matter. Unfortunately, their exposure to variety of abiotic stresses is unavoidable. Comparative analysis of interactive effect of UV-B and heavy metals (Cd/Zn) on nitrogen and phosphorus metabolism of three cyanobacteria (Anabaena, Microcystis, Nostoc) revealed additive inhibition (χ(2) significant p cyanobacteria suggests UV-B-induced structural change(s) in the enzyme/carriers. Metals seem to compete for the binding sites of the enzymes and carriers; as noticed for Anabaena and Microcystis showing change in Km while no change in the Km value of Nostoc suggests non-competitive nutrient uptake. Higher accumulation and more adverse effect on Na(+) and K(+) efflux proposes Cd as more toxic compared to Zn. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Disruption of the nitrogen regulatory gene AcareA in Acremonium chrysogenum leads to reduction of cephalosporin production and repression of nitrogen metabolism.

    Science.gov (United States)

    Li, Jinyang; Pan, Yuanyuan; Liu, Gang

    2013-12-01

    AcareA, encoding a homologue of the fungal nitrogen regulatory GATA zinc-finger proteins, was cloned from Acremonium chrysogenum. Gene disruption and genetic complementation revealed that AcareA was required for nitrogen metabolism and cephalosporin production. Disruption of AcareA resulted in growth defect in the medium using nitrate, uric acid and low concentration of ammonium, glutamine or urea as sole nitrogen source. Transcriptional analysis showed that the transcription of niaD/niiA was increased drastically when induced with nitrate in the wild-type and AcareA complemented strains but not in AcareA disruption mutant. Consistent with the reduction of cephalosporin production, the transcription of pcbAB, cefD2, cefEF and cefG encoding the enzymes for cephalosporin production was reduced in AcareA disruption mutant. Band shift assays showed that AcAREA bound to the promoter regions of niaD, niiA and the bidirectional promoter region of pcbAB-pcbC. Sequence analysis showed that all the AcAREA binding sites contain the consensus GATA elements. These results indicated that AcAREA plays an important role both in the regulation of nitrogen metabolism and cephalosporin production in A. chrysogenum. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Repeated inoculation of cattle rumen with bison rumen contents alters the rumen microbiome and improves nitrogen digestibility in cattle

    OpenAIRE

    Ribeiro, Gabriel O.; Oss, Daniela B.; He, Zhixiong; Gruninger, Robert J.; Elekwachi, Chijioke; Forster, Robert J.; Yang, WenZhu; Beauchemin, Karen A.; McAllister, Tim A.

    2017-01-01

    Future growth in demand for meat and milk, and the socioeconomic and environmental challenges that farmers face, represent a ?grand challenge for humanity?. Improving the digestibility of crop residues such as straw could enhance the sustainability of ruminant production systems. Here, we investigated if transfer of rumen contents from bison to cattle could alter the rumen microbiome and enhance total tract digestibility of a barley straw-based diet. Beef heifers were adapted to the diet for ...

  7. Static magnetic field treatment of seeds improves carbon and nitrogen metabolism under salinity stress in soybean.

    Science.gov (United States)

    Baghel, Lokesh; Kataria, Sunita; Guruprasad, Kadur Narayan

    2016-10-01

    The effectiveness of magnetopriming was assessed for alleviation of salt-induced adverse effects on soybean growth. Soybean seeds were pre-treated with static magnetic field (SMF) of 200 mT for 1 h to evaluate the effect of magnetopriming on growth, carbon and nitrogen metabolism, and yield of soybean plants under different salinity levels (0, 25, and 50 mM NaCl). The adverse effect of NaCl-induced salt stress was found on growth, yield, and various physiological attributes of soybeans. Results indicate that SMF pre-treatment significantly increased plant growth attributes, number of root nodules, nodules, fresh weight, biomass accumulation, and photosynthetic performance under both non-saline and saline conditions as compared to untreated seeds. Polyphasic chlorophyll a fluorescence (OJIP) transients from magnetically treated plants gave a higher fluorescence yield at J-I-P phase. Nitrate reductase activity, PIABS , photosynthetic pigments, and net rate of photosynthesis were also higher in plants that emerged from SMF pre-treated seeds as compared to untreated seeds. Leghemoglobin content and hemechrome content in root nodules were also increased by SMF pre-treatment. Thus pre-sowing exposure of seeds to SMF enhanced carbon and nitrogen metabolism and improved the yield of soybeans in terms of number of pods, number of seeds, and seed weight under saline as well as non-saline conditions. Consequently, SMF pre-treatment effectively mitigated adverse effects of NaCl on soybeans. It indicates that magnetopriming of dry soybean seeds can be effectively used as a pre-sowing treatment for alleviating salinity stress. Bioelectromagnetics. 37:455-470, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  8. Effects of dietary supplementation with green tea waste on growth, digestive enzyme and lipid metabolism of juvenile hybrid tilapia, Oreochromis niloticus × O. aureus.

    Science.gov (United States)

    Zheng, Qingmei; Han, Chunyan; Zhong, Yanmei; Wen, Rushu; Zhong, Ming

    2017-04-01

    An 8-week feeding trial was conducted to evaluate the effects of dietary supplementation with green tea waste (GTW) on growth, digestive enzyme and lipid metabolism of juvenile hybrid tilapia, Oreochromis niloticus × O. aureus. The fish (initial mean body weight, 12.63 ± 0.75 g) were fed five experimental diets that included 0 (control), 0.8, 1.6, 3.2 or 6.4 % of GTW in triplicate aquaria, twice daily. Growth performance, plasma metabolites content and liver and intestine digestive enzyme activities were determined. Fish accepted well all experimental diets during the trial, and no mortality was observed. The weight gain increased (P tilapia to improve growth performance, digestion efficacy and fat metabolism.

  9. A review on the bioenergetics of anaerobic microbial metabolism close to the thermodynamic limits and its implications for digestion applications.

    Science.gov (United States)

    Leng, Ling; Yang, Peixian; Singh, Shubham; Zhuang, Huichuan; Xu, Linji; Chen, Wen-Hsing; Dolfing, Jan; Li, Dong; Zhang, Yan; Zeng, Huiping; Chu, Wei; Lee, Po-Heng

    2018-01-01

    The exploration of the energetics of anaerobic digestion systems can reveal how microorganisms cooperate efficiently for cell growth and methane production, especially under low-substrate conditions. The establishment of a thermodynamically interdependent partnership, called anaerobic syntrophy, allows unfavorable reactions to proceed. Interspecies electron transfer and the concentrations of electron carriers are crucial for maintaining this mutualistic activity. This critical review summarizes the functional microorganisms and syntroph partners, particularly in the metabolic pathways and energy conservation of syntrophs. The kinetics and thermodynamics of propionate degradation to methane, reversibility of the acetate oxidation process, and estimation of microbial growth are summarized. The various routes of interspecies electron transfer, reverse electron transfer, and Poly-β-hydroxyalkanoate formation in the syntrophic community are also reviewed. Finally, promising and critical directions of future research are proposed. Fundamental insight in the activities and interactions involved in AD systems could serve as a guidance for engineered systems optimization and upgrade. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Arsenic Metabolism by Human Gut Microbiota upon In Vitro Digestion of Contaminated Soils

    Science.gov (United States)

    Background: Speciation analysis is essential when evaluating risks from arsenic (As) exposure. In an oral exposure scenario, the importance of presystemic metabolism by gut microorganisms has been evidenced with in vivo animal models and in vitro experiments with ...

  11. Nitrogen-corrected True Metabolizable Energy and Amino Acid Digestibility of Chinese Corn Distillers Dried Grains with Solubles in Adult Cecectomized Roosters

    Directory of Open Access Journals (Sweden)

    F. Li

    2013-06-01

    Full Text Available This study was conducted to evaluate chemical composition, nitrogen-corrected true metabolizable energy (TMEn and true amino acids digestibility of corn distillers dried grains with solubles (DDGS produced in China. Twenty five sources of corn DDGS was collected from 8 provinces of China. A precision-fed rooster assay was used to determine TMEn and amino acids digestibility with 35 adult cecectomized roosters, in which each DDGS sample was tube fed (30 g. The average content of ash, crude protein, total amino acid, ether extract, crude fiber and neutral detergent fiber were 4.81, 27.91, 22.51, 15.22, 6.35 and 37.58%, respectively. TMEn of DDGS ranged from 1,779 to 3,071 kcal/kg and averaged 2,517 kcal/kg. Coefficient of variation for non-amino acid crude protein, ether extract, crude fiber and TMEn were 55.0, 15.7, 15.9 and 17.1%, respectively. The average true amino acid digestibility was 77.32%. Stepwise regression analysis obtained the following equation: TMEn, kcal/kg = −2,995.6+0.88×gross energy+49.63×a* (BIC = 248.8; RMSE = 190.8; p0.05. These results suggest that corn DDGS produced in China has a large variation in chemical composition, and gross energy and a* value can be used to generate TMEn predict equation.

  12. Consumo e digestibilidade aparente da matéria seca, proteína e energia bruta, e balanço de nitrogênio das silagens de cinco genótipos de milho Consumption and apparent digestibility of dry matter, crude protein and crude energy, and balance of nitrogen of silages of five maize genotypes

    Directory of Open Access Journals (Sweden)

    G.A.R. Freitas

    2003-08-01

    Full Text Available Quantificaram-se o consumo voluntário e a digestibilidade aparente da matéria seca, proteína bruta, energia bruta e balanço de nitrogênio das silagens de cinco genótipos de milho (HT01, HT47C, HT129, AG 5011 e BR 3123. Foram utilizados 15 carneiros alojados em gaiolas metabólicas para coleta total de fezes e urina. O delineamento experimental foi o inteiramente ao acaso com cinco tratamentos e seis repetições. Não foram observadas diferenças entre os genótipos quanto ao consumo e digestibilidade da MS, da EB e da PB (P>0,05. Os consumos de MS, EB e PB digestíveis e energia metabolizável também não foram diferentes entre os híbridos (P>0,05. Quanto às relações consumo de energia digestível/consumo de MS e consumo de energia metabolizável/consumo de MS, o genótipo AG5011 foi semelhante ao HT01 (P>0,05 e superior aos demais (P0,05. Todos os genótipos produziram silagens de bom valor nutritivo, entretanto o genótipo AG5011 apresentou maior eficiência na utilização da energia (PThe voluntary intake and the apparent digestibility of dry matter, crude protein and crude energy and the nitrogen balance, of silages of five maize genotypes (HT01, HT47C, HT129, AG5011 and BR3123 were quantified. Fifteen sheep were stored in metabolic cages for total collection of feces and urine. A complete randomized design, with five treatments and six repetitions was used. The intake and digestibility of dry matter, crude protein and crude energy did not differ (P>0.05 among treatments. The intake of digestible dry matter, crude protein, crude energy and metabolic energy did not differ (P>0.05 among the genotypes. The ratios of digestible energy intake/dry matter intake and metabolic energy intake/dry matter intake of the genotype AG5011 silage was similar (P>0.05 to HT01, and higher than the other genotypes (P<0.05. All genotypes showed similar and positive nitrogen balance, and all of them produced silages of good nutritional value

  13. METABOLIC ENGINEERING TO DEVELOP A PATHWAY FOR THE SELECTIVE CLEAVAGE OF CARBON-NITROGEN BONDS

    Energy Technology Data Exchange (ETDEWEB)

    John J. Kilbane III

    2003-12-01

    pathway. The construction of a new metabolic pathway to selectively remove nitrogen from carbazole and other molecules typically found in petroleum should lead to the development of a process to improve oil refinery efficiency by reducing the poisoning, by nitrogen, of catalysts used in the hydrotreating and catalytic cracking of petroleum.

  14. Studies on the nitrogen metabolism of the large intestine of ruminants. 3

    International Nuclear Information System (INIS)

    Kijora, C.; Simon, O.; Bergner, H.; Goersch, R.; Jacobi, U.; Rossow, N.

    1986-01-01

    Two experiments were performed on sheep, receiving on maintenance level a pelleted straw ration high in crude fibre (straw 70.5%; dried sugar beet pulp 12%; cereals 10%; urea 2%; ammonium hydrogen carbonate 3%; minerals 2.5%). The animals were fitted with ileo-cecal re-entrant cannulas. The effects of the introduction of partly hydrolyzed straw meal into the digesta of the large intestine on the digestion processes in that segment were studied. Under these conditions the metabolism of 14 C and 15 N-labelled urea, which was given into the cecum, was estimated. In experiment 1 (E1; 2 animals) unlabelled, precollected digesta were hourly reintroduced together with 14 C and 15 N-labelled urea via the cecal cannula. In experiment 2 (E2; 3 animals) the digesta were supplemented with partly hydrolyzed straw meal (10% of the mean daily dry matter intake with the ration). The supplement of partly hydrolyzed straw meal caused an increase of the 15 N excretion with feces from 13.4% (E1) to 19.8% (E2) of the dose. The 15 N was mainly incorporated in the bacterial fraction (98% E1; 96% E2). As a reason for the increased 15 N incorporation into the bacterial fraction of 106.4 mg 15 N' in E2 vs. 67.3 mg 15 N' in the experiment without straw meal supplement the higher supply of energy as fermentable carbohydrates was assumed. (author)

  15. Microbial metabolic potential for carbon degradation and nutrient (nitrogen and phosphorus) acquisition in an ombrotrophic peatland.

    Science.gov (United States)

    Lin, Xueju; Tfaily, Malak M; Green, Stefan J; Steinweg, J Megan; Chanton, Patrick; Imvittaya, Aopeau; Chanton, Jeffrey P; Cooper, William; Schadt, Christopher; Kostka, Joel E

    2014-06-01

    This study integrated metagenomic and nuclear magnetic resonance (NMR) spectroscopic approaches to investigate microbial metabolic potential for organic matter decomposition and nitrogen (N) and phosphorus (P) acquisition in soils of an ombrotrophic peatland in the Marcell Experimental Forest (MEF), Minnesota, USA. This analysis revealed vertical stratification in key enzymatic pathways and taxa containing these pathways. Metagenomic analyses revealed that genes encoding laccases and dioxygenases, involved in aromatic compound degradation, declined in relative abundance with depth, while the relative abundance of genes encoding metabolism of amino sugars and all four saccharide groups increased with depth in parallel with a 50% reduction in carbohydrate content. Most Cu-oxidases were closely related to genes from Proteobacteria and Acidobacteria, and type 4 laccase-like Cu-oxidase genes were >8 times more abundant than type 3 genes, suggesting an important and overlooked role for type 4 Cu-oxidase in phenolic compound degradation. Genes associated with sulfate reduction and methanogenesis were the most abundant anaerobic respiration genes in these systems, with low levels of detection observed for genes of denitrification and Fe(III) reduction. Fermentation genes increased in relative abundance with depth and were largely affiliated with Syntrophobacter. Methylocystaceae-like small-subunit (SSU) rRNA genes, pmoA, and mmoX genes were more abundant among methanotrophs. Genes encoding N2 fixation, P uptake, and P regulons were significantly enriched in the surface peat and in comparison to other ecosystems, indicating N and P limitation. Persistence of inorganic orthophosphate throughout the peat profile in this P-limiting environment indicates that P may be bound to recalcitrant organic compounds, thus limiting P bioavailability in the subsurface. Comparative metagenomic analysis revealed a high metabolic potential for P transport and starvation, N2 fixation, and

  16. Nitrogen

    Science.gov (United States)

    Apodaca, L.E.

    2010-01-01

    Ammonia was produced by 13 companies at 23 plants in 16 states during 2009. Sixty percent of all U.S. ammonia production capacity was centered in Louisiana. Oklahoma and Texas because of those states' large reserves of natural gas, the dominant domestic feedstock. In 2009, U.S. producers operated at about 83 percent of their rated capacity (excluding plants that were idle for the entire year). Five companies — Koch Nitrogen Co.; Terra Industries Inc.; CF Industries Inc.; PCS Nitrogen Inc. and Agrium Inc., in descending order — accounted for 80 percent of the total U.S. ammonia production capacity. U.S. production was estimated to be 7.7 Mt (8.5 million st) of nitrogen (N) content in 2009 compared with 7.85 Mt (8.65 million st) of N content in 2008. Apparent consumption was estimated to have decreased to 12.1 Mt (13.3 million st) of N, a 10-percent decrease from 2008. The United States was the world's fourth-ranked ammonia producer and consumer following China, India and Russia. Urea, ammonium nitrate, ammonium phosphates, nitric acid and ammonium sulfate were the major derivatives of ammonia in the United States, in descending order of importance.

  17. Inorganic Carbon Turnover caused by Digestion of Carbonate Sands and Metabolic Activity of Holothurians

    Energy Technology Data Exchange (ETDEWEB)

    Schneider, Kenneth; Silverman, Jacob; Kravitz, Benjamin S.; Rivlin, Tanya; Schneider-Mor, Aya; Barbosa, Sergio; Byrne, Maria; Caldeira, Ken

    2013-11-20

    Recent measurements have shown that holothurians (sea cucumbers) play an important role in the cycling of CaCO3 in tropical coral reef systems through ingestion and processing of carbonate sediment. In this study inorganic additional aspects of carbon turnover were determined in laboratory incubations of Holothuria atra, H. leucospilota and Stichopus herrmanni from One Tree Reef, Great Barrier Reef. The pH values of the gut lumen ranged from 6.1 to 6.7 in animals with empty digestive tracts as opposed to 7.0 to 7.6 when digestive tracts were filled with sediment. Empty gut volume estimates for H. atra and S. herrmanni were 36 ± 4 mL and 151 ± 14 mL, respectively. Based on these measurements it is estimated that these species process 19 ± 2kg and 80 ± 7kg CaCO3 sand yr-1 per individual, respectively. The annual dissolution rates of H. atra and S. herrmanni of 6.5±1.9g and 9.6±1.4g, respectively, suggest that 0.05±0.02% and 0.1±0.02% of the CaCO3 processed through their gut annually is dissolved. During the incubations the CaCO3 dissolution was 0.07±0.01%, 0.04±0.01% and 0.21±0.05% of the fecal casts for H. atra, H. leucospilota and S. herrmanni, respectively. The CaCO3 saturation state for both aragonite and calcite minerals during laboratory incubations decreased markedly due to a greater increase in dissolved inorganic carbon (DIC) relative to total alkalinity (AT) as a result of respiration by the animals. Our results support the hypothesis that deposit feeders such as sea cucumbers play an important ecological role in the coral reef CaCO3 cycle.

  18. Inorganic carbon turnover caused by digestion of carbonate sands and metabolic activity of holothurians

    Science.gov (United States)

    Schneider, Kenneth; Silverman, Jacob; Kravitz, Ben; Rivlin, Tanya; Schneider-Mor, Aya; Barbosa, Sergio; Byrne, Maria; Caldeira, Ken

    2013-11-01

    Recent measurements have shown that holothurians (sea cucumbers) may play an important role in the cycling of CaCO3 in tropical coral reef systems through ingestion and processing of carbonate sediment. In this report, we present estimates of inorganic carbon turnover rates determined from laboratory incubations of Holothuria atra, Holothuria leucospilota and Stichopus herrmanni. The pH values of the gut lumen ranged from 7.0 to 7.6 when digestive tracts were filled with sediment compared with 6.1-6.7 in animals with empty digestive tracts. Empty gut volume estimates for H. atra and S. herrmanni were 36 ± 4 mL and 151 ± 14 mL, respectively. Based on these measurements and the density and porosity of carbonate sediments of coral reefs, it is estimated that these species process 19 ± 2 kg and 80 ± 7 kg CaCO3 sand yr-1 per individual, respectively. The annual CaCO3 dissolution rates per H. atra and S. herrmanni individual are estimated to be 6.5 ± 1.9 g and 9.6 ± 1.4 g, respectively, suggesting that 0.05 ± 0.02% and 0.1 ± 0.02% of the CaCO3 processed through their gut annually is dissolved. During incubations the CaCO3 dissolution of the fecal casts was 0.07 ± 0.01%, 0.04 ± 0.01% and 0.21 ± 0.05% for H. atra, H. leucospilota and S. herrmanni, respectively. The CaCO3 saturation state in the incubation seawater decreased markedly due to a greater increase in dissolved inorganic carbon (DIC) relative to total alkalinity (AT) as a result of respiration by the animals. Our results support the hypothesis that deposit feeders such as sea cucumbers play an important ecological role in the coral reef CaCO3 cycle.

  19. Title: Potassium application regulates nitrogen metabolism and osmotic adjustment in cotton (Gossypium hirsutum L.) functional leaf under drought stress.

    Science.gov (United States)

    Zahoor, Rizwan; Zhao, Wenqing; Abid, Muhammad; Dong, Haoran; Zhou, Zhiguo

    2017-08-01

    To evaluate the role of potassium (K) in maintaining nitrogen metabolism and osmotic adjustment development of cotton functional leaves to sustain growth under soil drought and rewatering conditions, the plants of two cotton cultivars Siza 3 (low-K sensitive) and Simian 3 (low-K tolerant), were grown under three different K rates (K0, K1, and K2; 0, 150, and 300kgK 2 Oha -1 , respectively) and exposed to drought stress with 40±5% soil relative water content (SRWC). The drought stress was applied at flowering stage by withholding water for eight days followed by rewatering to a well-watered level (75±5% SRWC). The results showed that drought-stressed plants of both cultivars showed a decrease in leaf relative water content (RWC) and osmotic potential in the functional leaves and developed osmotic adjustment with an increase in the contents of free amino acids, soluble sugars, inorganic K, and nitrate as compared to well-watered plants. In drought-stressed plants, nitrogen-metabolizing enzyme activities of nitrogen reductase (NR), glutamine synthetase (GS), and glutamate synthase (GOGAT) were diminished significantly (P≤0.05) along with decreased chlorophyll content and soluble proteins. However, drought-stressed plants under K application not only exhibited higher osmotic adjustment with greater accumulation of osmolytes but also regulated nitrogen metabolism by maintaining higher enzyme activities, soluble proteins, and chlorophyll content in functional leaves as compared to the plants without K application. Siza 3 showed better stability in enzyme activities and resulted in 89% higher seed cotton yield under K2 as compared to K0 in drought-stressed plants, whereas this increase was 53% in the case of Simian 3. The results of the study suggested that K application enhances cotton plants' potential for sustaining high nitrogen-metabolizing enzyme activities and related components to supplement osmotic adjustment under soil drought conditions. Copyright © 2017

  20. Dissimilatory metabolism of nitrogen oxides in bacteria: comparative reconstruction of transcriptional networks.

    Directory of Open Access Journals (Sweden)

    2005-10-01

    Full Text Available Bacterial response to nitric oxide (NO is of major importance since NO is an obligatory intermediate of the nitrogen cycle. Transcriptional regulation of the dissimilatory nitric oxides metabolism in bacteria is diverse and involves FNR-like transcription factors HcpR, DNR, and NnrR; two-component systems NarXL and NarQP; NO-responsive activator NorR; and nitrite-sensitive repressor NsrR. Using comparative genomics approaches, we predict DNA-binding motifs for these transcriptional factors and describe corresponding regulons in available bacterial genomes. Within the FNR family of regulators, we observed a correlation of two specificity-determining amino acids and contacting bases in corresponding DNA recognition motif. Highly conserved regulon HcpR for the hybrid cluster protein and some other redox enzymes is present in diverse anaerobic bacteria, including Clostridia, Thermotogales, and delta-proteobacteria. NnrR and DNR control denitrification in alpha- and beta-proteobacteria, respectively. Sigma-54-dependent NorR regulon found in some gamma- and beta-proteobacteria contains various enzymes involved in the NO detoxification. Repressor NsrR, which was previously known to control only nitrite reductase operon in Nitrosomonas spp., appears to be the master regulator of the nitric oxides' metabolism, not only in most gamma- and beta-proteobacteria (including well-studied species such as Escherichia coli, but also in Gram-positive Bacillus and Streptomyces species. Positional analysis and comparison of regulatory regions of NO detoxification genes allows us to propose the candidate NsrR-binding motif. The most conserved member of the predicted NsrR regulon is the NO-detoxifying flavohemoglobin Hmp. In enterobacteria, the regulon also includes two nitrite-responsive loci, nipAB (hcp-hcr and nipC (dnrN, thus confirming the identity of the effector, i.e. nitrite. The proposed NsrR regulons in Neisseria and some other species are extended to include

  1. Dissimilatory Metabolism of Nitrogen Oxides in Bacteria:Comparative Reconstruction of Transcriptional Networks

    Energy Technology Data Exchange (ETDEWEB)

    Rodionov, Dmitry A.; Dubchak, Inna L.; Arkin, Adam P.; Alm, EricJ.; Gelfand, Mikhail S.

    2005-09-01

    Bacterial response to nitric oxide (NO) is of major importance since NO is an obligatory intermediate of the nitrogen cycle. Transcriptional regulation of the dissimilatory nitric oxides metabolism in bacteria is diverse and involves FNR-like transcription factors HcpR, DNR and NnrR, two-component systems NarXL and NarQP, NO-responsive activator NorR, and nitrite sensitive repressor NsrR. Using comparative genomics approaches we predict DNA-binding signals for these transcriptional factors and describe corresponding regulons in available bacterial genomes. Within the FNR family of regulators, we observed a correlation of two specificity-determining amino acids and contacting bases in corresponding DNA signal. Highly conserved regulon HcpR for the hybrid cluster protein and some other redox enzymes is present in diverse anaerobic bacteria including Clostridia, Thermotogales and delta-proteobacteria. NnrR and DNR control denitrification in alpha- and beta-proteobacteria, respectively. Sigma-54-dependent NorR regulon found in some gamma- and beta-proteobacteria contains various enzymes involved in the NO detoxification. Repressor NsrR, which was previously known to control only nitrite reductase operon in Nitrosomonas spp., appears to be the master regulator of the nitric oxides metabolism not only in most gamma- and beta-proteobacteria (including well-studied species like Escherichia coli), but also in Gram-positive Bacillus and Streptomyces species. Positional analysis and comparison of regulatory regions of NO detoxification genes allows us to propose the candidate NsrR-binding signal. The most conserved member of the predicted NsrR regulon is the NO-detoxifying flavohemoglobin Hmp. In enterobacteria, the regulon includes also two nitrite-responsive loci, nipAB (hcp-hcr) and nipC(dnrN), thus confirming the identity of the effector, i.e., nitrite. The proposed NsrR regulons in Neisseria and some other species are extended to include denitrification genes. As the

  2. [Effects of nitrogen application rate on faba bean fusarium wilt and rhizospheric microbial metabolic functional diversity].

    Science.gov (United States)

    Dong, Yan; Yang, Zhi-xian; Dong, Kun; Tang, Li; Zheng, Yi; Hu, Guo-bin

    2013-04-01

    A field plot experiment was conducted to study the effects of different nitrogen (N) application rates on the microbial functional diversity in faba bean rhizosphere and the relationships between the microbial functional diversity and the occurrence of faba bean fusarium wilt. Four nitrogen application rates were installed, i. e. , N0(0 kg hm-2 , N1 (56. 25 kg hm-2) , N2(112. 5 kg hm-2), and N3 (168.75 kg hm-2), and Biolog microbial analysis system was applied to study the damage of faba bean fusarium wilt and the rhizospheric microbial metabolic functional diversity. Applying N (N1 N2, and N3) decreased the disease index of faba bean fusarium wilt and the quantity of Fusarium oxysporum significantly, and increased the quantities of bacteria and actinomyces and the ratios of bacteria/fungi and actinomyces/fungi significantly, with the peak values of bacteria and actinomyces, bacteria/fungi, and actinomyces/fungi, and the lowest disease index and F. oxysporum density in N2. As compared with N0, applying N increased the AWCD value significantly, but the effects of different N application rates on the ability of rhizospheric microbes in utilizing six types of carbon sources had definite differences. Under the application of N, the utilization rates of carbohydrates, carboxylic acids, and amino acids by the rhizospheric microbes were higher. Principal component analysis demonstrated that applying N changed the rhizospheric microbial community composition obviously, and the carbohydrates, carboxylic acids, and amino acids were the sensitive carbon sources differentiating the changes of the microbial community induced by N application. Applying N inhibited the utilization of carbohydrates and carboxylic acids but improved the utilization of amino acids and phenolic acids by the rhizospheric microbes, which could be one of the main reasons of applying N being able to reduce the harm of faba bean fusarium wilt. It was suggested that rationally applying N could increase the

  3. Long-term monitoring reveals carbon-nitrogen metabolism key to microcystin production in eutrophic lakes

    Directory of Open Access Journals (Sweden)

    Lucas J Beversdorf

    2015-05-01

    Full Text Available The environmental drivers contributing to cyanobacterial dominance in aquatic systems have been extensively studied. However, understanding of toxic versus non-toxic cyanobacterial population dynamics and the mechanisms regulating cyanotoxin production remain elusive, both physiologically and ecologically. One reason is the disconnect between laboratory and field-based studies. Here, we combined three years of temporal data, including microcystin (MC concentrations, 16 years of long-term ecological research, and 10 years of molecular data to investigate the potential factors leading to the selection of toxic Microcystis and MC production. Our analysis revealed that nitrogen (N speciation and inorganic carbon (C availability might be important drivers of Microcystis population dynamics and that an imbalance in cellular C: N ratios may trigger MC production. More specifically, precipitous declines in ammonium concentrations lead to a transitional period of N stress, even in the presence of high nitrate concentrations, that we call the toxic phase. Following the toxic phase, temperature and cyanobacterial abundance remained elevated but MC concentrations drastically declined. Increases in ammonium due to lake turnover may have led to down regulation of MC synthesis or a shift in the community from toxic to non-toxic species. While total phosphorus (P to total N ratios were relatively low over the time-series, MC concentrations were highest when total N to total P ratios were also highest. Similarly, high C: N ratios were also strongly correlated to the toxic phase. We propose a metabolic model that corroborates molecular studies and reflects our ecological observations that C and N metabolism may regulate MC production physiologically and ecologically. In particular, we hypothesize that an imbalance between 2-oxoglutarate and ammonium in the cell regulates MC synthesis in the environment.

  4. Studies on the nitrogen metabolism of the large intestine of ruminants. 4

    International Nuclear Information System (INIS)

    Bergner, H.; Kijora, C.; Simon, O.; Goersch, R.

    1986-01-01

    Two experiments were performed with wethers (body weight 34 to 44 kg) receiving a ration rich in crude fiber at maintenance level. The animals were fitted with ileo-cecal cannulas into which 14 C-, 15 N-labelled urea together with digesta was introduced hourly for a 24 hours period (V 1 ; 2 animals). In experiment two (V 2 ; 3 animals) in addition HCl-partly hydrolyzed straw meal was introduced. After ureolytic degradation the intracecal applied urea entered mainly the intermediary metabolism. The resulting ammonia was resynthesized to urea without any time lag. The rate constant for the increase in 15 N labelling of urea was 3.2 d -1 in both experiments. Urea leaves the plasma with half-lives of 10.6 (V 1 ) and 5.2 (V 2 ) hours. More than 60% of the applied urea were excreted with urine. Formed 14 CO 2 appeared at proportions of 66% (V 2 ) and 71% (V 1 ) in the respiration gases. Both, the decline of the 14 C activity in blood plasma and the specific 14 C activity of CO 2 in the respiration gases after the end of the labelling period do not follow a kinetic of first order. The 15 N labelling of the NH 3 nitrogen in ileal digesta was very high and reached plateau values similar with those of plasma urea (2.54 vs. 2.56 atom-% 15 N excess). A direct entry of plasma urea into the small intestine was concluded. (author)

  5. Adjustment of growth and central metabolism to a mild but sustained nitrogen-limitation in Arabidopsis.

    Science.gov (United States)

    Tschoep, Hendrik; Gibon, Yves; Carillo, Petronia; Armengaud, Patrick; Szecowka, Marek; Nunes-Nesi, Adriano; Fernie, Alisdair R; Koehl, Karin; Stitt, Mark

    2009-03-01

    We have established a simple soil-based experimental system that allows a small and sustained restriction of growth of Arabidopsis by low nitrogen (N). Plants were grown in a large volume of a peat-vermiculite mix that contained very low levels of inorganic N. As a control, inorganic N was added in solid form to the peat-vermiculite mix, or plants were grown in conventional nutrient-rich solids. The low N growth regime led to a sustained 20% decrease of the relative growth rate over a period of 2 weeks, resulting in a two- to threefold decrease in biomass in 35- to 40-day-old plants. Plants in the low N regime contained lower levels of nitrate, lower nitrate reductase activity, lower levels of malate, fumarate and other organic acids and slightly higher levels of starch, as expected from published studies of N-limited plants. However, their rosette protein content was unaltered, and total and many individual amino acid levels increased compared with N-replete plants. This metabolic phenotype reveals that Arabidopsis responds adaptively to low N by decreasing the rate of growth, while maintaining the overall protein content, and maintaining or even increasing the levels of many amino acids.

  6. Pulmonary arachidonic acid metabolism following acute exposures to ozone and nitrogen dioxide

    International Nuclear Information System (INIS)

    Schlesinger, R.B.; Driscoll, K.E.; Gunnison, A.F.; Zelikoff, J.T.

    1990-01-01

    Ozone (O 3 ) and nitrogen dioxide (NO 2 ) are common air pollutants, and exposure to these gases has been shown to affect pulmonary physiology, biochemistry, and structure. This study examined their ability to modulate arachidonic acid metabolites (eicosanoids) in the lungs. Rabbits were exposed for 2 h to O 3 at 0.1, 0.3, or 1 ppm; NO 2 at 1, 3, or 10 ppm; or to a mixture of 0.3 ppm O 3 and 3 ppm NO 2 . Groups of animals sacrificed either immediately or 24 h after each exposure underwent broncho-pulmonary lavage. Selected eicosanoids were assessed in lavage fluid by radioimmunoassay. Increases in prostaglandins E2 (PGE2) and F2 alpha (PGF2 alpha) were found immediately after exposure to 1 ppm O 3 . Exposure to 10 ppm NO 2 resulted in a depression of 6-keto-PGF1 alpha, while thromboxane B2 (TxB2) was elevated after exposure to 1 ppm NO 2 and depressed following 3 and 10 ppm. The O 3 /NO 2 mixture resulted in synergistic increases in PGE2 and PGF2 alpha, with the response appearing to be driven by O 3 . This study has demonstrated that acute exposure to either O 3 or NO 2 can alter pulmonary arachidonic acid metabolism and that the responses to these oxidants differ, both quantitatively and qualitatively

  7. Metabolic Engineering to Develop a Pathway for the Selective Cleavage of Carbon-Nitrogen Bonds

    Energy Technology Data Exchange (ETDEWEB)

    John J. Kilbane II

    2005-10-01

    The objective of the project is to develop a biochemical pathway for the selective cleavage of C-N bonds in molecules found in petroleum. Specifically a novel biochemical pathway will be developed for the selective cleavage of C-N bonds in carbazole. The cleavage of the first C-N bond in carbazole is accomplished by the enzyme carbazole dioxygenase, that catalyzes the conversion of carbazole to 2-aminobiphenyl-2,3-diol. The genes encoding carbazole dioxygenase were cloned from Sphingomonas sp. GTIN11 and from Pseudomonas resinovorans CA10. The selective cleavage of the second C-N bond has been challenging, and efforts to overcome that challenge have been the focus of recent research in this project. Enrichment culture experiments succeeded in isolating bacterial cultures that can metabolize 2-aminobiphenyl, but no enzyme capable of selectively cleaving the C-N bond in 2-aminobiphenyl has been identified. Aniline is very similar to the structure of 2-aminobiphenyl and aniline dioxygenase catalyzes the conversion of aniline to catechol and ammonia. For the remainder of the project the emphasis of research will be to simultaneously express the genes for carbazole dioxygenase and for aniline dioxygenase in the same bacterial host and then to select for derivative cultures capable of using carbazole as the sole source of nitrogen.

  8. Effect of Chromium(VI Toxicity on Enzymes of Nitrogen Metabolism in Clusterbean (Cyamopsis tetragonoloba L.

    Directory of Open Access Journals (Sweden)

    Punesh Sangwan

    2014-01-01

    Full Text Available Heavy metals are the intrinsic component of the environment with both essential and nonessential types. Their excessive levels pose a threat to plant growth and yield. Also, some heavy metals are toxic to plants even at very low concentrations. The present investigation (a pot experiment was conducted to determine the affects of varying chromium(VI levels (0.0, 0.5, 1.0, 2.0, and 4.0 mg chromium(VI kg−1 soil in the form of potassium dichromate on the key enzymes of nitrogen metabolism in clusterbean. Chromium treatment adversely affect nitrogenase, nitrate reductase, nitrite reductase, glutamine synthetase, and glutamate dehydrogenase in various plant organs at different growth stages as specific enzyme activity of these enzymes decreased with an increase in chromium(VI levels from 0 to 2.0 mg chromium(VI kg−1 soil and 4.0 mg chromium(VI kg−1 soil was found to be lethal to clusterbean plants. In general, the enzyme activity increased with advancement of growth to reach maximum at flowering stage and thereafter decreased at grain filling stage.

  9. Effects of plane of nutrition on growth, feed intake, digestibility and nitrogen balance in Murrah graded male buffalo (Bubalus bubalis) calves in Nepal.

    Science.gov (United States)

    Kumagai, Hajime; Baral, Bodh R; Shiino, Tatsu; Devkota, Naba R; Oishi, Kazato; Hirooka, Hiroyuki; Kolachhapati, Mana R; Tiwari, Ishwor C P

    2012-01-01

    An experiment was conducted using 17 male buffalo calves to assess the effects of plane of nutrition on dry matter intake (DMI), daily gain (DG), body size measurement, apparent digestibility and nitrogen (N) balance. To attain 250kg BW, the calves were allocated into three groups: H, L-H and L, receiving the concentrate at 1.50% of BW, 0.75% of BW until 190kg BW and 1.50% thereafter and 0.75% of BW, respectively. The animals had ad libitum access to urea-treated rice straw (UTRS). The DMI of UTRS through the experiment was higher in L and L-H than H, showing 3.52, 2.90 and 2.62kg/day, respectively (Pcalves in Nepal. © 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.

  10. Evaluation of some feedstuffs with special emphasis on the effect of nitrate and other non-protein nitrogen fractions on ruminal microbial metabolism

    International Nuclear Information System (INIS)

    Nikolic, J.A.

    1988-01-01

    Green herbage grown under widely different conditions was examined for nitrate content. The mean value was 0.14% (range 0.01-0.32%) NO 3 -N in the dry matter (DM). It was concluded that the cut green fodder would induce high levels of blood methaemoglobin when fed to ruminants in mixed diets. Nevertheless, experiments in vitro indicated that relatively small amounts of dietary nitrate induced considerable microbial nitrate reducing activity in rumen contents. Moreover, nitrate reduction to ammonia was accompanied by alterations in microbial sulphur and energy metabolism. A technique for determining organic matter digestibility (OMD) in vitro was standardized and used to evaluate the potential nutritive value of some fruit wastes. Studies on apple pomace silage indicated that added urea did not significantly increase the silage protein content but remained as a potential source of non-protein nitrogen for rumen microorganisms. Apple pomace ensiled alone or preferably with other ingredients was acceptable to sheep and cattle, particularly as a supplement to their winter rations. (author). 27 refs, 2 figs, 5 tabs

  11. Regulation of Nitrogen Metabolism by GATA Zinc Finger Transcription Factors in Yarrowia lipolytica

    OpenAIRE

    Pomraning, Kyle R.; Bredeweg, Erin L.; Baker, Scott E.

    2017-01-01

    ABSTRACT Fungi accumulate lipids in a manner dependent on the quantity and quality of the nitrogen source on which they are growing. In the oleaginous yeast Yarrowia lipolytica, growth on a complex source of nitrogen enables rapid growth and limited accumulation of neutral lipids, while growth on a simple nitrogen source promotes lipid accumulation in large lipid droplets. Here we examined the roles of nitrogen catabolite repression and its regulation by GATA zinc finger transcription factors...

  12. Protein digestion in ruminants

    African Journals Online (AJOL)

    a balance between synthesis and hydrolysis. Aside from .... be used to follow the synthesis of this protein fraction. (Clarke, 1977a) .... form of digestive enzymes, urea and ammonia (Egan, ..... decreasing urine-nitrogen excretion (Thornton, Bird,.

  13. Plant available nitrogen from anaerobically digested sludge and septic tank sludge applied to crops grown in the tropics.

    Science.gov (United States)

    Sripanomtanakorn, S; Polprasert, C

    2002-04-01

    Agricultural land is an attractive alternative for the disposal of biosolids since it utilises the recyclable nutrients in the production of crops. In Thailand and other tropical regions, limited field-study information exists on the effect of biosolids management strategies on crop N utilisation and plant available N (PAN) of biosolids. A field study was conducted to quantify the PAN of the applied biosolids, and to evaluate the N uptake rates of some tropical crops. Sunflower (Helianthus annuus) and tomato (Lycopersicon esculentum) were chosen in this study. Two types of biosolids used were: anaerobically digested sludge and septic tank sludge. The soil is acid sulfate and is classified as Sulfic Tropaquepts with heavy clay in texture. The anaerobically digested sludge applied rates were: 0, 156 and 312 kg N ha(-1) for the sunflower plots, and 0, 586, and 1172 kg N ha(-1) for the tomato plots. The septic tank sludge applied rates were: 0, 95 and 190 kg N ha(-1) for the sunflower plots, and 0, 354 and 708 kg N ha(-1) for the tomato plots, respectively. The results indicated the feasibility of applying biosolids to grow tropical crops. The applications of the anaerobically digested sludge and the septic tank sludge resulted in the yields of sunflower seeds and tomato fruits and the plant N uptakes comparable or better than that applied with only the chemical fertiliser. The estimated PAN of the anaerobically digested sludge was about 27-42% of the sludge organic N during the growing season. For the septic tank sludge, the PAN was about 15-58% of the sludge organic N. It is interesting to observe that an increase of the rate of septic tank sludge incorporated into this heavy clay soil under the cropping system resulted in the decrease of N mineralisation rate. This situation could cause the reduction of yield and N uptake of crops.

  14. The effect of aerobic exercise training on growth performance, digestive enzyme activities and postprandial metabolic response in juvenile qingbo (Spinibarbus sinensis).

    Science.gov (United States)

    Li, Xiu-Ming; Yu, Li-Juan; Wang, Chuan; Zeng, Ling-Qing; Cao, Zhen-Dong; Fu, Shi-Jian; Zhang, Yao-Guang

    2013-09-01

    Continual swimming exercise usually promotes growth in fish at a moderate water velocity. We hypothesized that the improvement in growth in exercise-trained fish may be accompanied by increases in digestive enzyme activity, respiratory capacity and, hence, postprandial metabolism. Juvenile qingbo fish (Spinibarbus sinensis) were subjected to aerobic training for 8weeks at a water velocity of control (3cms(-1)), 1, 2 and 4 body length (bl)s(-1) at a constant temperature of 25°C. The feed intake (FI), food conversion rate (FCR), specific growth rate (SGR), whole-body composition, trypsin and lipase activities, maximal oxygen consumption (M˙O2max) and postprandial M˙O2 response were measured at the end of the training period. Aerobic exercise training induced a significant increase in FI compared with the control group, while the FCR of the 4bls(-1) group was significantly lower than for the other three groups (PFI after long-term training; (3) and aerobic exercise training boosted the activity of digestive enzymes and maximum digestive metabolism, which could favor fast digestion and growth in juvenile S. sinensis. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Structure of nitrogen-converting communities induced by hydraulic retention time and COD/N ratio in constantly aerated granular sludge reactors treating digester supernatant.

    Science.gov (United States)

    Cydzik-Kwiatkowska, Agnieszka; Rusanowska, Paulina; Zielińska, Magdalena; Bernat, Katarzyna; Wojnowska-Baryła, Irena

    2014-02-01

    This study investigated how hydraulic retention time (HRT) and COD/N ratio affect nitrogen-converting consortia in constantly aerated granules treating high-ammonium digester supernatant. Three HRTs (10, 13, 19 h) were tested at COD/N ratios of 4.5 and 2.3. Denaturing gradient gel electrophoresis and relative real-time PCR were used to characterize the microbial communities. When changes in HRT and COD/N increased nitrogen loading, the ratio of the relative abundance of aerobic to anaerobic ammonium-oxidizers decreased. The COD/N ratio determined the species composition of the denitrifiers; however, Thiobacillus denitrificans, Pseudomonas denitrificans and Azoarcus sp. showed a high tolerance to the environmental conditions and occurred in the granules from all reactors. Denitrifier genera that support granule formation were identified, such as Pseudomonas, Shinella, and Flavobacterium. In aerated granules, nirK-possessing bacteria were more diverse than nirS-possessing bacteria. At a low COD/N ratio, N2O-reducer diversity increased because of the presence of bacteria known as aerobic denitrifiers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Nitrogen utilization and digestibility of amino acids by lambs fed a high-concentrate diet with limestone or magnesium oxide.

    Science.gov (United States)

    Christiansen, M L; Webb, K E

    1990-07-01

    Effects were evaluated of high dietary levels of magnesium oxide (MgO) or limestone on DM, OM and CP digestibility, N balance and intestinal absorption of amino acids by lambs fed a high concentrate diet. Twelve wether lambs equipped with abomasal and ileal cannulas were blocked by weight and breeding and allotted to treatments in a randomized block design in two consecutive trials. Diets were control (800 g), control plus 1.5% MgO (812 g), control plus 1.5% limestone (812 g) and control plus 3.0% limestone (824 g) fed in two equal portions at 12-h intervals. Ruminal fluid pH differences were small. The pH of ileal digesta was greater (P less than .05) with MgO than with limestone (8.23 vs 7.73). Fecal pH was higher (P less than .01) for lambs fed all mineral treatments (avg 8.75) than for lambs fed the control (7.61) and was higher (P less than .01) when MgO (9.53) rather than limestone (8.36) was fed. Ruminal NH3N was lower (P less than .01) when lambs were fed MgO (11.9 mg/dl) compared with limestone (avg 31.2 mg/dl). Preintestinal DM digestibility was greatest (P less than .10) with limestone (avg 49.5%) feeding compared with feeding MgO (31.2%) or the control (35.4%). About 41.5% more essential (P less than .05) and 48% more nonessential (P less than .03) amino acids reached the small intestine when MgO was fed than when limestone was fed. Partial digestibility of amino acids in the small intestine was reduced (P less than .03) an average of 5 percentage units when MgO or limestone was fed. Feeding high levels of MgO or limestone to lambs did not improve the overall digestibility of DM, OM or CP. In fact, feeding high levels of MgO or limestone appeared to be detrimental, reducing intestinal absorption of amino acids.

  17. Effect of UV-B on enzymes of nitrogen metabolism in the cyanobacterium Nostoc calcicola

    International Nuclear Information System (INIS)

    Kumar, A.; Sinha, R.P.; Häder, D. P.

    1996-01-01

    The effects of ultraviolet-B (UV-B; 280–315 nm) irradiation on nitrogenase and nitrate reductase (NR) activity have been studied in the filamentous and heterocystous N 2 -fixing cyanobacterium Nostoc calcicola. Exposure of cultures to UV-B (5W/m 2 ) for as little as 30 min caused complete inactivation of nitrogenase activity whereas nitrate reductase activity was stimulated twofold in comparison to one exposed to fluorescent white light. GS activity was also inhibited by UV-B treatment, but there was no total loss of activity even after 4 h. NR activity showed a gradual stimulation up to 4 h and thereafter it became constant. Stimulation was also obtained in reductant deficient cultures (12 h incubation in the dark) suggesting independence of NR of PS-II under UV-B. NR activity was also unaffected in the presence of DCMU, a known inhibitor of PS-II. However, both O 2 evolution and 14 CO 2 uptake were completely abolished following 30 min of UV-B treatment. Addition of the protein synthesis inhibitor chloramphenicol (25 μg/mL) to cultures did not show any inhibitory effect on NR activity. SDS-PAGE analysis of UV-B treated cultures elicited gradual loss of protein bands with increasing duration of exposure. Our findings suggest that UV-B irradiance has differential effects on the enzymes of the nitrogen metabolism in the cyanobacterium Nostoc calcicola. Further studies are needed to reveal the exact mechanism involved in the stimulation of NR activity by UV-B. Whether UV-B has a direct effect on NO 2 − accumulation in the cells needs detailed investigation. (author)

  18. The Assimilation of Diazotroph-Derived Nitrogen by Scleractinian Corals Depends on Their Metabolic Status

    Directory of Open Access Journals (Sweden)

    Vanessa N. Bednarz

    2017-01-01

    Full Text Available Tropical corals are associated with a diverse community of dinitrogen (N2-fixing prokaryotes (diazotrophs providing the coral an additional source of bioavailable nitrogen (N in oligotrophic waters. The overall activity of these diazotrophs changes depending on the current environmental conditions, but to what extent it affects the assimilation of diazotroph-derived N (DDN by corals is still unknown. Here, in a series of 15N2 tracer experiments, we directly quantified DDN assimilation by scleractinian corals from the Red Sea exposed to different environmental conditions. We show that DDN assimilation strongly varied with the corals’ metabolic status or with phosphate availability in the water. The very autotrophic shallow-water (~5 m corals showed low or no DDN assimilation, which significantly increased under elevated phosphate availability (3 µM. Corals that depended more on heterotrophy (i.e., bleached and deep-water [~45 m] corals assimilated significantly more DDN, which contributed up to 15% of the corals’ N demand (compared to 1% in shallow corals. Furthermore, we demonstrate that a substantial part of the DDN assimilated by deep corals was likely obtained from heterotrophic feeding on fixed N compounds and/or diazotrophic cells in the mucus. Conversely, in shallow corals, the net release of mucus, rich in organic carbon compounds, likely enhanced diazotroph abundance and activity and thereby the release of fixed N to the pelagic and benthic reef community. Overall, our results suggest that DDN assimilation by corals varies according to the environmental conditions and is likely linked to the capacity of the coral to acquire nutrients from seawater.

  19. Quantifying ruminal nitrogen metabolism using the omasal sampling technique in cattle--a meta-analysis.

    Science.gov (United States)

    Broderick, G A; Huhtanen, P; Ahvenjärvi, S; Reynal, S M; Shingfield, K J

    2010-07-01

    Mixed model analysis of data from 32 studies (122 diets) was used to evaluate the precision and accuracy of the omasal sampling technique for quantifying ruminal-N metabolism and to assess the relationships between nonammonia-N flow at the omasal canal and milk protein yield. Data were derived from experiments in cattle fed North American diets (n=36) based on alfalfa silage, corn silage, and corn grain and Northern European diets (n=86) composed of grass silage and barley-based concentrates. In all studies, digesta flow was quantified using a triple-marker approach. Linear regressions were used to predict microbial-N flow to the omasum from intake of dry matter (DM), organic matter (OM), or total digestible nutrients. Efficiency of microbial-N synthesis increased with DM intake and there were trends for increased efficiency with elevated dietary concentrations of crude protein (CP) and rumen-degraded protein (RDP) but these effects were small. Regression of omasal rumen-undegraded protein (RUP) flow on CP intake indicated that an average 32% of dietary CP escaped and 68% was degraded in the rumen. The slope from regression of observed omasal flows of RUP on flows predicted by the National Research Council (2001) model indicated that NRC predicted greater RUP supply. Measured microbial-N flow was, on average, 26% greater than that predicted by the NRC model. Zero ruminal N-balance (omasal CP flow=CP intake) was obtained at dietary CP and RDP concentrations of 147 and 106 g/kg of DM, corresponding to ruminal ammonia-N and milk urea N concentrations of 7.1 and 8.3mg/100mL, respectively. Milk protein yield was positively related to the efficiency of microbial-N synthesis and measured RUP concentration. Improved efficiency of microbial-N synthesis and reduced ruminal CP degradability were positively associated with efficiency of capture of dietary N as milk N. In conclusion, the results of this study indicate that the omasal sampling technique yields valuable estimates

  20. Dynamic optimal control of homeostasis: an integrative system approach for modeling of the central nitrogen metabolism in Saccharomyces cerevisiae.

    Science.gov (United States)

    van Riel, N A; Giuseppin, M L; Verrips, C T

    2000-01-01

    The theory of dynamic optimal metabolic control (DOMC), as developed by Giuseppin and Van Riel (Metab. Eng., 2000), is applied to model the central nitrogen metabolism (CNM) in Saccharomyces cerevisiae. The CNM represents a typical system encountered in advanced metabolic engineering. The CNM is the source of the cellular amino acids and proteins, including flavors and potentially valuable biomolecules; therefore, it is also of industrial interest. In the DOMC approach the cell is regarded as an optimally controlled system. Given the metabolic genotype, the cell faces a control problem to maintain an optimal flux distribution in a changing environment. The regulation is based on strategies and balances feedback control of homeostasis and feedforward regulation for adaptation. The DOMC approach is an integrative, holistic approach, not based on mechanistic descriptions and (therefore) not biased by the variation present in biochemical and molecular biological data. It is an effective tool to structure the rapidly increasing amount of data on the function of genes and pathways. The DOMC model is used successfully to predict the responses of pulses of ammonia and glutamine to nitrogen-limited continuous cultures of a wild-type strain and a glutamine synthetase-negative mutant. The simulation results are validated with experimental data.

  1. Comparative genome analysis of central nitrogen metabolism and its control by GlnR in the class Bacilli

    Directory of Open Access Journals (Sweden)

    Kormelink Tom

    2012-05-01

    Full Text Available Abstract Background The assimilation of nitrogen in bacteria is achieved through only a few metabolic conversions between alpha-ketoglutarate, glutamate and glutamine. The enzymes that catalyze these conversions are glutamine synthetase, glutaminase, glutamate dehydrogenase and glutamine alpha-ketoglutarate aminotransferase. In low-GC Gram-positive bacteria the transcriptional control over the levels of the related enzymes is mediated by four regulators: GlnR, TnrA, GltC and CodY. We have analyzed the genomes of all species belonging to the taxonomic families Bacillaceae, Listeriaceae, Staphylococcaceae, Lactobacillaceae, Leuconostocaceae and Streptococcaceae to determine the diversity in central nitrogen metabolism and reconstructed the regulation by GlnR. Results Although we observed a substantial difference in the extent of central nitrogen metabolism in the various species, the basic GlnR regulon was remarkably constant and appeared not affected by the presence or absence of the other three main regulators. We found a conserved regulatory association of GlnR with glutamine synthetase (glnRA operon, and the transport of ammonium (amtB-glnK and glutamine/glutamate (i.e. via glnQHMP, glnPHQ, gltT, alsT. In addition less-conserved associations were found with, for instance, glutamate dehydrogenase in Streptococcaceae, purine catabolism and the reduction of nitrite in Bacillaceae, and aspartate/asparagine deamination in Lactobacillaceae. Conclusions Our analyses imply GlnR-mediated regulation in constraining the import of ammonia/amino-containing compounds and the production of intracellular ammonia under conditions of high nitrogen availability. Such a role fits with the intrinsic need for tight control of ammonia levels to limit futile cycling.

  2. Fasting or fear: disentangling the roles of predation risk and food deprivation in the nitrogen metabolism of consumers.

    Science.gov (United States)

    Dalton, Christopher M; Tracy, Karen E; Hairston, Nelson G; Flecker, Alexander S

    2018-03-01

    Predators can alter nutrient cycles simply by inducing stress in prey. This stress accelerates prey's protein catabolism, nitrogen waste production, and nitrogen cycling. Yet predators also reduce the feeding rates of their prey, inducing food deprivation that is expected to slow protein catabolism and nitrogen cycling. The physiology of prey under predation risk thus balances the influences of predation risk and food deprivation, and this balance is central to understanding the role of predators in nutrient cycles. We explored the separate and combined effects of predation risk and food deprivation on prey physiology and nutrient cycling by exposing guppies (Poecilia reticulata) to predation risk and food deprivation in a 2 × 2 design. We simulated predation risk using chemical cues from a natural predator of guppies, and we created food deprivation by rationing food availability. We measured guppy response as food consumption, growth, tissue energy density, tissue carbon:nitrogen, and nitrogen (N) excretion and assimilation. We found that N-linked physiological processes (N consumption, assimilation, excretion) were strongly affected by predation risk, independent of food consumption. Guppies excreted substantially less under predation risk than they did under food deprivation or control conditions. These results suggest that predation risk, per se, triggers physiological changes in guppies that increase N retention and decrease N excretion. We suggest that slower N metabolism under predation risk is an adaptive response that minimizes protein loss in the face of predictable, predator-induced food restriction. Notably, N metabolism shares common hormonal control with food seeking behavior, and we speculate that increased N retention is a direct and immediate result of reduced food seeking under predation risk. Contrary to predation-stress-based hypotheses for how predators affect nutrient cycling by prey, our result indicates that even short-term exposure to

  3. Metabolic features involved in drought stress tolerance mechanisms in peanut nodules and their contribution to biological nitrogen fixation.

    Science.gov (United States)

    Furlan, Ana Laura; Bianucci, Eliana; Castro, Stella; Dietz, Karl-Josef

    2017-10-01

    Legumes belong to the most important crops worldwide. They increase soil fertility due their ability to establish symbiotic associations with soil microorganisms, known as rhizobia, capable of fixing nitrogen from the atmosphere. However, they are frequently exposed to abiotic stress conditions in particular drought. Such adverse conditions impair the biological nitrogen fixation (BNF) and depend largely on the legume. Therefore, two peanut cultivars with contrasting tolerance to drought, namely the more tolerant EC-98 and the sensitive Granoleico, were investigated to elucidate the relative contribution of BNF to the tolerance to drought. The tolerant cultivar EC-98 sustained growth and BNF similar to the control condition despite the reduced water potential and photosynthesis, suggesting the functioning of distinct metabolic pathways that contributed to enhance the tolerance. The biochemical and metabolomics approaches revealed that nodules from the tolerant cultivar accumulated trehalose, proline and gamma-aminobutyric acid (GABA), metabolites with known function in protecting against drought stress. The amide metabolism was severely affected in nodules from the sensitive cultivar Granoleico as revealed by the low content of asparagine and glutamine in the drought stressed plants. The sensitive cultivar upon rehydration was unable to re-establish a metabolism similar to well-watered plants. This was evidenced by the low level of metabolites and, transcripts and specific activities of enzymes from the carbon (sucrose synthase) and nitrogen (glutamine synthetase) metabolism which decreased below the values of control plants. Therefore, the increased content of metabolites with protective functions under drought stress likely is crucial for the full restoration upon rehydration. Smaller changes of drought stress-related metabolites in nodule are another trait that contributes to the effective control of BNF in the tolerant peanut cultivar (EC-98). Copyright © 2017

  4. Rumen Degradability and Post-ruminal Digestion of Dry Matter, Nitrogen and Amino Acids of Three Protein Supplements

    Directory of Open Access Journals (Sweden)

    Wei Gao

    2015-04-01

    Full Text Available This study evaluated the in situ ruminal degradability, and subsequent small intestinal digestibility (SID of dry matter, crude protein (CP, and amino acids (AA of cottonseed meal (CSM, sunflower seed meal (SFSM and distillers dried grains with solubles (DDGS by using the modified three-step in vitro procedure. The ruminal degradability and subsequent SID of AA in rumen-undegradable protein (RUP-AA varied among three protein supplements. The result show that the effective degradability of DM for SFSM, CSM, and DDGS was 60.8%, 56.4%, and 41.0% and their ruminal fermentable organic matter was 60.0%, 55.9%, and 39.9%, respectively. The ruminal degradable protein (RDP content in CP for SFSM, CSM, and DDGS was 68.3%, 39.0%, and 32.9%, respectively, at the ruminal solid passage rate of 1.84%/h. The SFSM is a good source of RDP for rumen micro-organisms; however, the SID of RUP of SFSM was lower. The DDGS and CSM are good sources of RUP for lambs to digest in the small intestine to complement ruminal microbial AA of growing lambs. Individual RUP-AA from each protein source was selectively removed by the rumen micro-organisms, especially for Trp, Arg, His, and Lys (p<0.01. The SID of individual RUP-AA was different within specific RUP origin (p<0.01. Limiting amino acid was Leu for RUP of CSM and Lys for both RUP of SFSM and DDGS, respectively. Therefore, different protein supplements with specific limitations should be selected and combined carefully in growing lambs ration to optimize AA balance.

  5. Rumen Degradability and Post-ruminal Digestion of Dry Matter, Nitrogen and Amino Acids of Three Protein Supplements.

    Science.gov (United States)

    Gao, Wei; Chen, Aodong; Zhang, Bowen; Kong, Ping; Liu, Chenli; Zhao, Jie

    2015-04-01

    This study evaluated the in situ ruminal degradability, and subsequent small intestinal digestibility (SID) of dry matter, crude protein (CP), and amino acids (AA) of cottonseed meal (CSM), sunflower seed meal (SFSM) and distillers dried grains with solubles (DDGS) by using the modified three-step in vitro procedure. The ruminal degradability and subsequent SID of AA in rumen-undegradable protein (RUP-AA) varied among three protein supplements. The result show that the effective degradability of DM for SFSM, CSM, and DDGS was 60.8%, 56.4%, and 41.0% and their ruminal fermentable organic matter was 60.0%, 55.9%, and 39.9%, respectively. The ruminal degradable protein (RDP) content in CP for SFSM, CSM, and DDGS was 68.3%, 39.0%, and 32.9%, respectively, at the ruminal solid passage rate of 1.84%/h. The SFSM is a good source of RDP for rumen micro-organisms; however, the SID of RUP of SFSM was lower. The DDGS and CSM are good sources of RUP for lambs to digest in the small intestine to complement ruminal microbial AA of growing lambs. Individual RUP-AA from each protein source was selectively removed by the rumen micro-organisms, especially for Trp, Arg, His, and Lys (p<0.01). The SID of individual RUP-AA was different within specific RUP origin (p<0.01). Limiting amino acid was Leu for RUP of CSM and Lys for both RUP of SFSM and DDGS, respectively. Therefore, different protein supplements with specific limitations should be selected and combined carefully in growing lambs ration to optimize AA balance.

  6. Metabolism of poly-β-hydroxybutyric acid in bacteroids of Rhizobium lupini in connection with nitrogen fixation and photosynthesis

    International Nuclear Information System (INIS)

    Romanov, V.I.; Fedulova, N.G.; Tchermenskaya, I.E.; Shramko, V.I.; Molchanov, M.I.; Kretovich, W.L.

    1980-01-01

    The darkening of lupin plants grown in a sand culture on a nitrogen-free medium at a stage of initial flowering led to a sharply decreased nitrogen fixation intensity which eventually ceased. Decreased intensity of nitrogen fixation in bacteroids was accompanied by an accumulation of poly-β-hydroxybutyric acid (PHB): in the course of 10-20 h (depending upon temperature) its content increased by 2.5-3.0 times. If, following darkening, the plants were once again exposed to light, an abrupt increase of nitrogen fixation intensity was observed and a simultaneous decrease of PHB content. It has been shown that lupin's exposure to light in 14 CO 2 atmosphere lasting 19 h resulted in the latter's incorporation into PHB, bacteroids and into the entire nodule; these processes developed almost in parallel. During the early period of vegetation growth prior to flowering, the PHB content of bacteroids decreased from 13 14 to 3.4% of dry weight, whereas the intensity of nitrogen fixation was raised. Concurrently increase of the activity of some enzymes connected with the PHB metabolism (aceto-acetyl-CoA-reductase, acetyl-CoA acetyl transferase PHB-depolymerase, (CoA-transferase, of 3-ketoacids) occured. The plants' subsequent ageing and reduction of nitrogen fixation intensity led to a noticeable increase of PHB content and a decrease of the above mentioned enzymes' activity. The specific activity of β-hydroxybutyric dehydrogenase involved with PHB catabolism was high and was maintained at a constant level throughout the entire vegetative period. (orig.)

  7. Effect of gamma radiation on the nitrogen metabolism of Paecilomyces Violacea

    International Nuclear Information System (INIS)

    Salama, A.H.; Nadia, M.; Elzawahry, Y.A.; Abo Elkhair, I.A.

    1989-01-01

    Quantitative variabilities could be noticed in the nitrogen utilization and mycelial content of mats arising from gamma irradiated and non-irradiated Inocula of P.Violacea. The two lowest doses, 0.1 and 0.25 KGy, showed an increase in nitrate uptake and nitrogen utilization more than control by 7.43 and 15.61% for nitrate uptake and 8.33 and 14.89 for nitrogen utilization respectively, while the higher doses (0.5 up to 3.0 KGy) were inhibitory to the above parameters and also to protein synthesis. The chemical changes in the composition of fungal mats reveal that the peptide-N was the highest in amount as compared with the other nitrogen fractions. The protein-N was second in rank of quantity followed by the amino-N, while the nitrate-N was the least in amount compared to other nitrogen fractions at all radiation treatments

  8. Nitrogen and carbon source balance determines longevity, independently of fermentative or respiratory metabolism in the yeast Saccharomyces cerevisiae.

    Science.gov (United States)

    Santos, Júlia; Leitão-Correia, Fernanda; Sousa, Maria João; Leão, Cecília

    2016-04-26

    Dietary regimens have proven to delay aging and age-associated diseases in several eukaryotic model organisms but the input of nutritional balance to longevity regulation is still poorly understood. Here, we present data on the role of single carbon and nitrogen sources and their interplay in yeast longevity. Data demonstrate that ammonium, a rich nitrogen source, decreases chronological life span (CLS) of the prototrophic Saccharomyces cerevisiae strain PYCC 4072 in a concentration-dependent manner and, accordingly, that CLS can be extended through ammonium restriction, even in conditions of initial glucose abundance. We further show that CLS extension depends on initial ammonium and glucose concentrations in the growth medium, as long as other nutrients are not limiting. Glutamine, another rich nitrogen source, induced CLS shortening similarly to ammonium, but this effect was not observed with the poor nitrogen source urea. Ammonium decreased yeast CLS independently of the metabolic process activated during aging, either respiration or fermentation, and induced replication stress inhibiting a proper cell cycle arrest in G0/G1 phase. The present results shade new light on the nutritional equilibrium as a key factor on cell longevity and may contribute for the definition of interventions to promote life span and healthy aging.

  9. Visualizing Single Cell Biology: Nanosims Studies of Carbon and Nitrogen Metabolism in Diazotrophic Cyanobacteria

    Science.gov (United States)

    Pett-Ridge, J.; Finzi, J. A.; Capone, D. G.; Popa, R.; Nealson, K. H.; Ng, W.; Spormann, A. M.; Hutcheon, I. D.; Weber, P. K.

    2007-12-01

    Filamentous nitrogen fixing (diazotrophic) cyanobacteria are key players in global nutrient cycling, but the relationship between CO2- and N2-fixation and intercellular exchange of these elements remains poorly understood in many genera. These bacteria are faced with the challenge of isolating regions of N-fixation (O2 inhibited) and photosynthetic (O2 producing) activity. We used isotope labeling in conjunction with a high-resolution isotope and elemental mapping technique (NanoSIMS) to quantitatively describe 13C and 15N uptake and transport in two aquatic cyanobacteria grown on NaH13CO3 and 15N2. The technical challenges of tracing isotopes within individual bacteria can be overcome with high resolution Secondary Ion Mass Spectrometry (NanoSIMS). In NanoSIMS analysis, samples are sputtered with an energetic primary beam (Cs+, O-) liberating secondary ions that are separated by the mass spectrometer and detected in a suite of electron multipliers. Five isotopic species may be analyzed concurrently with spatial resolution as fine as 50nm. A high sensitivity isotope ratio 'map' can then be generated for the analyzed area. Using sequentially harvested cyanobacteria in conjunction with enriched H13CO3 and 15N2 incubations, we measured temporal enrichment patterns that evolve over the course of a day's growth and suggest tightly regulated changes in fixation kinetics. With a combination of TEM, SEM and NanoSIMS analyses, we also mapped the distribution of C, N and Mo (a critical nitrogenase co-factor) isotopes in intact cells. Our results suggest that NanoSIMS mapping of metal enzyme co-factors may be a powerful method of identifying physiological and morphological characteristics within individual bacterial cells, and could be used to provide a 3-dimensional context for more traditional analyses such as immunogold labeling. Finally, we resolved patterns of isotope enrichment at multiple spatial scales: sub-cellular variation, cell-cell differences along filaments

  10. A continuous-flow system for measuring in vitro oxygen and nitrogen metabolism in separated stream communities

    DEFF Research Database (Denmark)

    Prahl, C.; Jeppesen, E.; Sand-Jensen, Kaj

    1991-01-01

    on the stream bank, consists of several macrophyte and sediment chambers equipped with a double-flow system that ensures an internal water velocity close to that in the stream and which, by continuously renewing the water, mimics diel fluctuation in stream temperature and water chemistry. Water temperature...... production and dark respiration occurred at similar rates (6-7g O2 m-2 day-1), net balance being about zero. Inorganic nitrogen was consumed both by the sediment and to a greater extent by the macrophytes, the diel average consumption being 1g N m-2 day-1. 3. The sum of the activity in the macrophyte...... and sediment chambers corresponded to the overall activity of the stream section as determined by upstream/downstream mass balance. This indicates that the results obtained with the continuous-flow chambers realistically describe the oxygen and the nitrogen metabolism of the stream....

  11. The Nitrogen Moieties of Dietary Nonessential Amino Acids Are Distinctively Metabolized in the Gut and Distributed to the Circulation in Rats.

    Science.gov (United States)

    Nakamura, Hidehiro; Kawamata, Yasuko; Kuwahara, Tomomi; Sakai, Ryosei

    2017-08-01

    Background: Although previous growth studies in rodents have indicated the importance of dietary nonessential amino acids (NEAAs) as nitrogen sources, individual NEAAs have different growth-promoting activities. This phenomenon might be attributable to differences in the nitrogen metabolism of individual NEAAs. Objective: The aim of this study was to compare nitrogen metabolism across dietary NEAAs with the use of their 15 N isotopologues. Methods: Male Fischer rats (8 wk old) were given 1.0 g amino acid-defined diets containing either 15 N-labeled glutamate, glutamine (amino or amide), aspartate, alanine, proline, glycine, or serine hourly for 5-6 h. Then, steady-state amino acid concentrations and their 15 N enrichments in the gut and in portal and arterial plasma were measured by an amino acid analyzer and LC tandem mass spectrometry, respectively. Results: The intestinal 15 N distribution and portal-arterial balance of 15 N metabolites indicated that most dietary glutamate nitrogen (>90% of dietary input) was incorporated into various amino acids, including alanine, proline, and citrulline, in the gut. Dietary aspartate nitrogen, alanine nitrogen, and amino nitrogen of glutamine were distributed similarly to other amino acids both in the gut and in the circulation. In contrast, incorporation of the nitrogen moieties of dietary proline, serine, and glycine into other amino acids was less than that of other NEAAs, although interconversion between serine and glycine was very active. Cluster analysis of 15 N enrichment data also indicated that dietary glutamate nitrogen, aspartate nitrogen, alanine nitrogen, and the amino nitrogen of glutamine were distributed similarly to intestinal and circulating amino acids. Further, the analysis revealed close relations between intestinal and arterial 15 N enrichment for each amino acid. The steady-state 15 N enrichment of arterial amino acids indicated that substantial amounts of circulating amino acid nitrogen are derived

  12. Nitrification-driven forms of nitrogen metabolism in microbial mat communities thriving along an ammonium-enriched subsurface geothermal stream

    Science.gov (United States)

    Nishizawa, Manabu; Koba, Keisuke; Makabe, Akiko; Yoshida, Naohiro; Kaneko, Masanori; Hirao, Shingo; Ishibashi, Jun-ichiro; Yamanaka, Toshiro; Shibuya, Takazo; Kikuchi, Tohru; Hirai, Miho; Miyazaki, Junichi; Nunoura, Takuro; Takai, Ken

    2013-07-01

    We report here the concurrence and interaction among forms of nitrogen metabolism in thermophilic microbial mat communities that developed in an ammonium-abundant subsurface geothermal stream. First, the physical and chemical conditions of the stream water at several representative microbial mat habitats (including upper, middle and downstream sites) were characterized. A thermodynamic calculation using these physical and chemical conditions predicted that nitrification consisting of ammonia and nitrite oxidations would provide one of the largest energy yields of chemolithotrophic metabolisms. Second, near-complete prokaryotic 16S rRNA gene clone analysis was conducted for representative microbial mat communities at the upper, middle and downstream sites. The results indicated a dynamic shift in the 16S rRNA gene phylotype composition through physical and chemical variations of the stream water. The predominant prokaryotic components varied from phylotypes related to hydrogeno (H2)- and thio (S)-trophic Aquificales, thermophilic methanotrophs and putative ammonia-oxidizing Archaea (AOA) located upstream (72 °C) to the phylotypes affiliated with putative AOA and nitrite-oxidizing bacteria (NOB) located at the middle and downstream sites (65 and 57 °C, respectively). In addition, the potential in situ metabolic activities of different forms of nitrogen metabolism were estimated through laboratory experiments using bulk microbial mat communities. Finally, the compositional and isotopic variation in nitrogen compounds was investigated in the stream water flowing over the microbial mats and in the interstitial water inside the mats. Although the stream water was characterized by a gradual decrease in the total ammonia concentration (ΣNH3: the sum of ammonia and ammonium concentrations) and a gradual increase in the total concentration of nitrite and nitrate (NO2- + NO3-), the total inorganic nitrogen concentration (TIN: the sum of ΣNH3, NO2- and NO3- concentrations

  13. Volatile sulphur compounds in wines related to yeast metabolism and nitrogen composition of grape musts

    OpenAIRE

    Moreira, N.; Mendesa, F.; Pereira, O.; Pinho, P. Guedes de

    2002-01-01

    The influence of nitrogen compounds in grape musts on the content of sulphur compounds of wines was studied. Different vinifications were performed with the addition of methionine (20 mg l−1) and/or cysteine (40 mg l−1) to grape musts before alcoholic fermentation. Six grape musts, with different nitrogen composition, from cultivars of the ‘Vinhos Verdes’ Region, in Portugal, were used. Addition of methionine to grape musts enhanced the content of wines in 3-(methylthio)-1-propanol, ...

  14. Effect of Chernobyl radionuclides accumulation on the photosynthetic processes and nitrogen metabolism of Lupines Luteus L

    International Nuclear Information System (INIS)

    Zabolotnyj, A.I.; Goncharova, N.V.; Domash, V.I.; Sheverdov, V.V.; Akadehmiya Navuk Belarusi, Minsk

    1995-01-01

    The 134 Cs, 137 Cs and chlorophyll content activity of photochemical reaction in chloroplasts and symbiotic nitrogen fixation in root modules, activity of neutral protease, BAPAse and trypsin inhibitors were investigated for seeds to yellow lupine (Lupines luteus L). The level of radioactive contamination induced a tendency to change the activity of photosynthetic reaction and nitrogen fixation, significant changes in a set of trypsin inhibitors were found in nature lupine seeds

  15. Roostocks/Scion/Nitrogen Interactions Affect Secondary Metabolism in the Grape Berry

    OpenAIRE

    Habran, Aude; Commisso, Mauro; Helwi, Pierre; Hilbert, Ghislaine; Negri, Stefano; Ollat, Nathalie; Gom?s, Eric; van Leeuwen, Cornelis; Guzzo, Flavia; Delrot, Serge

    2016-01-01

    ABSTRACT : The present work investigates the interactions between soil content, rootstock and scion by focusing on the effects of roostocks and nitrogen supply on grape berry content. Scions of Cabernet Sauvignon (CS) and Pinot Noir (PN) varieties were grafted either on Riparia Gloire de Montpellier (RGM) or 110 Richter (110R) rootstock. The 4 rooststock/scion combinations were fertilized with 3 different levels of nitrogen after fruit set. Both in 2013 and 2014, N supply increased N uptake ...

  16. Methanosarcina Play an Important Role in Anaerobic Co-Digestion of the Seaweed Ulva lactuca: Taxonomy and Predicted Metabolism of Functional Microbial Communities.

    Directory of Open Access Journals (Sweden)

    Jamie A FitzGerald

    Full Text Available Macro-algae represent an ideal resource of third generation biofuels, but their use necessitates a refinement of commonly used anaerobic digestion processes. In a previous study, contrasting mixes of dairy slurry and the macro-alga Ulva lactuca were anaerobically digested in mesophilic continuously stirred tank reactors for 40 weeks. Higher proportions of U. lactuca in the feedstock led to inhibited digestion and rapid accumulation of volatile fatty acids, requiring a reduced organic loading rate. In this study, 16S pyrosequencing was employed to characterise the microbial communities of both the weakest (R1 and strongest (R6 performing reactors from the previous work as they developed over a 39 and 27-week period respectively. Comparing the reactor communities revealed clear differences in taxonomy, predicted metabolic orientation and mechanisms of inhibition, while constrained canonical analysis (CCA showed ammonia and biogas yield to be the strongest factors differentiating the two reactor communities. Significant biomarker taxa and predicted metabolic activities were identified for viable and failing anaerobic digestion of U. lactuca. Acetoclastic methanogens were inhibited early in R1 operation, followed by a gradual decline of hydrogenotrophic methanogens. Near-total loss of methanogens led to an accumulation of acetic acid that reduced performance of R1, while a slow decline in biogas yield in R6 could be attributed to inhibition of acetogenic rather than methanogenic activity. The improved performance of R6 is likely to have been as a result of the large Methanosarcina population, which enabled rapid removal of acetic acid, providing favourable conditions for substrate degradation.

  17. Methanosarcina Play an Important Role in Anaerobic Co-Digestion of the Seaweed Ulva lactuca: Taxonomy and Predicted Metabolism of Functional Microbial Communities.

    Science.gov (United States)

    FitzGerald, Jamie A; Allen, Eoin; Wall, David M; Jackson, Stephen A; Murphy, Jerry D; Dobson, Alan D W

    2015-01-01

    Macro-algae represent an ideal resource of third generation biofuels, but their use necessitates a refinement of commonly used anaerobic digestion processes. In a previous study, contrasting mixes of dairy slurry and the macro-alga Ulva lactuca were anaerobically digested in mesophilic continuously stirred tank reactors for 40 weeks. Higher proportions of U. lactuca in the feedstock led to inhibited digestion and rapid accumulation of volatile fatty acids, requiring a reduced organic loading rate. In this study, 16S pyrosequencing was employed to characterise the microbial communities of both the weakest (R1) and strongest (R6) performing reactors from the previous work as they developed over a 39 and 27-week period respectively. Comparing the reactor communities revealed clear differences in taxonomy, predicted metabolic orientation and mechanisms of inhibition, while constrained canonical analysis (CCA) showed ammonia and biogas yield to be the strongest factors differentiating the two reactor communities. Significant biomarker taxa and predicted metabolic activities were identified for viable and failing anaerobic digestion of U. lactuca. Acetoclastic methanogens were inhibited early in R1 operation, followed by a gradual decline of hydrogenotrophic methanogens. Near-total loss of methanogens led to an accumulation of acetic acid that reduced performance of R1, while a slow decline in biogas yield in R6 could be attributed to inhibition of acetogenic rather than methanogenic activity. The improved performance of R6 is likely to have been as a result of the large Methanosarcina population, which enabled rapid removal of acetic acid, providing favourable conditions for substrate degradation.

  18. Nitrogen Metabolism in Lactating Goats Fed with Diets Containing Different Protein Sources

    Directory of Open Access Journals (Sweden)

    A. B. Santos

    2014-05-01

    Full Text Available This study aimed to evaluate urea excretion, nitrogen balance and microbial protein synthesis in lactating goats fed with diets containing different protein sources in the concentrate (soybean meal, cottonseed meal, aerial part of cassava hay and leucaena hay. Four Alpine goats whose mean body weight was 42.6±6.1 kg at the beginning of the experiment, a mean lactation period of 94.0±9.0 days and a production of 1.7±0.4 kg of milk were distributed in a 4×4 Latin square with four periods of 15 days. Diets were formulated to be isonitrogenous, containing 103.0 g/kg of CP, 400 g/kg of Tifton 85 hay and 600 g/kg of concentrate. Diet containing cottonseed meal provided (p<0.05 increased excretion of urea and urea nitrogen in the urine (g/d and mg/kg of BW when compared with leucaena hay. The diets affected the concentrations of urea nitrogen in plasma (p<0.05 and excretion of urea nitrogen in milk, being that soybean meal and cottonseed meal showed (p<0.05 higher than the average aerial part of the cassava hay. The use of diets with cottonseed meal as protein source in the concentrate in feeding of lactating goats provides greater nitrogen excretion in urine and negative nitrogen balance, while the concentrate with leucaena hay as a source of protein, provides greater ruminal microbial protein synthesis.

  19. Effect of pectin extracted from citrus pulp on digesta characteristics and nutrient digestibility in broilers chickens

    Directory of Open Access Journals (Sweden)

    Vanessa Karla Silva

    2013-08-01

    Full Text Available The experiment was carried out to evaluate the effects of continuous ingestion of pectin on intestinal viscosity, intestinal transit time, excreta moisture content, nutrient digestibility and energy metabolism of broilers at starter and growth phases. We used 240 one-day-old Cobb male broiler chicks, distributed in a completely randomized experimental design. Treatments consisted of four concentrations of pectin (0, 10, 30 and 50 g kg-1 with six replicates of 10 birds each. The ingestion of pectin supplied in the feed by broilers at the starter phase increased intestinal viscosity and intestinal transit time, reduced excreta moisture, improved the use of apparent metabolizable energy, nitrogen-corrected apparent metabolizable energy, coefficient of apparent metabolizability, coefficient of nitrogen-corrected apparent metabolizability, apparent digestibility coefficient of crude protein and organic matter; worsened calcium utilization and coefficients of apparent digestibility of dry matter; and did not influence the coefficients of apparent digestibility of crude fat, ash and phosphorus. Pectin ingestion during the growth phase increased intestinal viscosity and apparent digestibility coefficients of ash and organic matter, but decreased the dry matter, crude fat, crude protein and calcium. Intestinal transit time, energy metabolism and apparent digestibility coefficient of crude protein showed quadratic behavior according to pectin levels in the feed. Therefore, pectin ingestion by broilers at the starter phase increases intestinal viscosity and intestinal transit time, reduces excreta moisture and improves energy utilization, whereas at the growth phase nutrient digestibility is decreased.

  20. Effects of dietary coarsely ground corn and litter type on broiler live performance, litter characteristics, gastrointestinal tract development, apparent ileal digestibility of energy and nitrogen, and intestinal morphology.

    Science.gov (United States)

    Xu, Y; Stark, C R; Ferket, P R; Williams, C M; Auttawong, S; Brake, J

    2015-03-01

    The objectives of this study were to evaluate the effects of the dietary inclusion of 2 coarsely ground corn (CC) levels (0 or 50%) in diets of broilers reared on 2 litter types (new wood shavings or used litter) on live performance, litter characteristics, gastrointestinal tract (GIT) development, apparent ileal digestibility (AID) of energy and nitrogen (N), and intestinal morphology. No interaction effects between CC level and litter type were observed on live performance. No litter effect was observed on live performance. Dietary inclusion of 50% CC increased BW at 35 d (Plitter treatment (litter N) increased absolute and relative proventriculus weight (Plitter type was observed for litter N, where the 50% CC treatment reduced litter N regardless of litter type (Plitter N was reduced by new litter only among birds fed 0% CC (Plitter pH (Plitter increased jejunum villi and ileum villi height (PLitter type affected some GIT traits and functions but did not affect live performance. © 2015 Poultry Science Association Inc.

  1. Effects of increasing dietary concentrations of specific structured triacylglycerides on performance and nitrogen and energy metabolism in broiler chickens

    DEFF Research Database (Denmark)

    Zheng, C.T.; Jørgensen, Henning; Høy, Carl-Erik

    2006-01-01

    treatments as two series of 40 chicks: a basal diet with graded levels of STG of 0, 20, 40, 60 and 80 g/kg diet at the expense of rapeseed oil were fed to the chickens in groups of four. At 12d of age the chickens were placed pair-wise in metabolism cages. The grower period (d 13-36) was divided into four...... effect on digestibility of STG. Weight of small intestine and colon decreased with increasing inclusion of STG. 4. Utilisation of dietary protein relative to intake increased while that of retained fat tended to decrease resulting in a decreased utilisation of metabolisable energy (RE/ME) in birds...

  2. Processing of soybean meal and 00-rapeseed meal reduces protein digestibility and pig growth performance but does not affect nitrogen solubilization along the small intestine.

    Science.gov (United States)

    Hulshof, T G; van der Poel, A F B; Hendriks, W H; Bikker, P

    2016-06-01

    An experiment was conducted to determine the effects of processing of soybean meal (SBM) and 00-rapeseed meal (RSM) on N solubilization in chyme, CP digestibility along the small intestine, metabolic load as determined by organ weight, body composition, and growth performance in growing pigs. The SBM and RSM were processed by secondary toasting (at 95°C for 30 min) in the presence of lignosulfonate, resulting in processed SBM (pSBM) and processed RSM (pRSM) as a model for overprocessed protein sources. Fifty-four growing pigs were each fed 1 of the 6 experimental diets. Four of the diets contained SBM, pSBM, RSM, or pRSM as the sole protein source. The remaining 2 experimental diets contained pSBM or pRSM and were supplemented with crystalline AA to the same standardized ileal digestible AA levels as the SBM or RSM diet. Pigs were slaughtered at 40 kg, and organ weights were recorded. The organs plus blood and empty carcass were analyzed for CP content. The small intestine was divided into 3 segments, and chyme samples were taken from the last meter of each segment. Chyme of the SBM, pSBM, RSM, and pRSM diets was centrifuged to separate the soluble and insoluble fractions, and N content was determined in the latter. The amount of insoluble N as a fraction of N in chyme at each small intestinal segment was not affected by processing. Diet type, comprising effects of processing and supplementing crystalline AA, affected ( < 0.05) the G:F and standardized ileal digestibility (SID) of CP. Processing reduced G:F from 0.56 to 0.38 for SBM and 0.49 to 0.40 for RSM, whereas supplementing crystalline AA increased G:F to the level of the SBM and RSM diets. Processing reduced the SID of CP from 87.2% to 69.2% for SBM and 71.0% to 52.2% for RSM. Diet type affected ( < 0.05) the CP content in the empty body, with processing reducing this content from 170 to 144 g/kg empty BW for SBM and 157 to 149 g/kg empty BW for RSM and supplementing crystalline AA restoring this content

  3. Nitrogen metabolism correlates with the acclimation of photosynthesis to short-term water stress in rice (Oryza sativa L.).

    Science.gov (United States)

    Zhong, Chu; Cao, Xiaochuang; Bai, Zhigang; Zhang, Junhua; Zhu, Lianfeng; Huang, Jianliang; Jin, Qianyu

    2018-04-01

    Nitrogen metabolism is as sensitive to water stress as photosynthesis, but its role in plant under soil drying is not well understood. We hypothesized that the alterations in N metabolism could be related to the acclimation of photosynthesis to water stress. The features of photosynthesis and N metabolism in a japonica rice 'Jiayou 5' and an indica rice 'Zhongzheyou 1' were investigated under mild and moderate soil drying with a pot experiment. Soil drying increased non-photochemical quenching (NPQ) and reduced photon quantum efficiency of PSII and CO 2 fixation in 'Zhongzheyou 1', whereas the effect was much slighter in 'Jiayou 5'. Nevertheless, the photosynthetic rate of the two cultivars showed no significant difference between control and water stress. Soil drying increased nitrate reducing in leaves of 'Zhongzheyou 1', characterized by enhanced nitrate reductase (NR) activity and lowered nitrate content; whereas glutamate dehydrogenase (GDH), glutamic-oxaloacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) were relative slightly affected. 'Jiayou 5' plants increased the accumulation of nitrate under soil drying, although its NR activity was increased. In addition, the activities of GDH, GOT and GPT were typically increased under soil drying. Besides, amino acids and soluble sugar were significantly increased under mild and moderate soil drying, respectively. The accumulation of nitrate, amino acid and sugar could serve as osmotica in 'Jiayou 5'. The results reveal that N metabolism plays diverse roles in the photosynthetic acclimation of rice plants to soil drying. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  4. Linking carbon and nitrogen metabolism to depth distribution of submersed macrophytes using high ammonium dosing tests and a lake survey.

    Science.gov (United States)

    Yuan, Guixiang; Cao, Te; Fu, Hui; Ni, Leyi; Zhang, Xiaolin; Li, Wei; Song, Xin; Xie, Ping; Jeppesen, Erik

    2013-12-01

    Strategies of carbon (C) and nitrogen (N) utilisation are among the factors determining plant distribution. It has been argued that submersed macrophytes adapted to lower light environments are more efficient in maintaining C metabolic homeostasis due to their conservative C strategy and ability to balance C shortage. We studied how depth distributions of 12 submersed macrophytes in Lake Erhai, China, were linked to their C-N metabolic strategies when facing acute [Formula: see text] dosing.[Formula: see text] dosing changed C-N metabolism significantly by decreasing the soluble carbohydrate (SC) content and increasing the [Formula: see text]-N and free amino acid (FAA) content of plant tissues.The proportional changes in SC contents in the leaves and FAA contents in the stems induced by [Formula: see text] dosing were closely correlated (positive for SC and negative for FAA) with the colonising water depths of the plants in Lake Erhai, the plants adapted to lower light regimes being more efficient in maintaining SC and FAA homeostasis.These results indicate that conservative carbohydrate metabolism of submersed macrophytes allowed the plants to colonise greater water depths in eutrophic lakes, where low light availability in the water column diminishes carbohydrate production by the plants.

  5. In vitro starch digestion correlates well with rate and extent of starch digestion in broiler chickens

    NARCIS (Netherlands)

    Weurding, R.E.; Veldman, R.; Veen, W.A.G.; Aar, van der P.J.; Verstegen, M.W.A.

    2001-01-01

    Current feed evaluation systems for poultry are based on digested components (fat, protein and nitrogen-free extracts). Digestible starch is the most important energy source in broiler chicken feeds and is part of the nitrogen-free extract fraction. Digestible starch may be predicted using an in

  6. Digestive Diseases

    Science.gov (United States)

    ... cells and provide energy. This process is called digestion. Your digestive system is a series of hollow organs joined ... are also involved. They produce juices to help digestion. There are many types of digestive disorders. The ...

  7. Photoperiod length paces the temporal orchestration of cell cycle and carbon-nitrogen metabolism in Crocosphaera watsonii.

    Science.gov (United States)

    Dron, Anthony; Rabouille, Sophie; Claquin, Pascal; Talec, Amélie; Raimbault, Virginie; Sciandra, Antoine

    2013-12-01

    We analysed the effect of photoperiod length (PPL) (16:8 and 8:16 h of light-dark regime, named long and short PPL, respectively) on the temporal orchestration of the two antagonistic, carbon and nitrogen acquisitions in the unicellular, diazotrophic cyanobacterium Crocosphaera watsonii strain WH8501 growing diazotrophically. Carbon and nitrogen metabolism were monitored at high frequency, and their patterns were compared with the cell cycle progression. The oxygen-sensitive N2 fixation process occurred mainly during the dark period, where photosynthesis cannot take place, inducing a light-dark cycle of cellular C : N ratio. Examination of circadian patterns in the cell cycle revealed that cell division occurred during the midlight period, (8 h and 4 h into the light in the long and short PPL conditions, respectively), thus timely separated from the energy-intensive diazotrophic process. Results consistently show a nearly 5 h time lag between the end of cell division and the onset of N2 fixation. Shorter PPLs affected DNA compaction of C. watsonii cells and also led to a decrease in the cell division rate. Therefore, PPL paces the growth of C. watsonii: a long PPL enhances cell division while a short PPL favours somatic growth (biomass production) with higher carbon and nitrogen cell contents. © 2013 Society for Applied Microbiology and John Wiley & Sons Ltd.

  8. Ileal and faecal protein digestibility measurement in humans and other non-ruminants - a comparative species view

    NARCIS (Netherlands)

    Hendriks, W.H.; Baal, van J.; Bosch, G.

    2012-01-01

    A comparative non-ruminant species view of the contribution of the large intestinal metabolism to inaccuracies in nitrogen and amino acid absorption measurements is provided to assess potential implications for the determination of crude protein/amino acid digestibility in adult humans consuming

  9. Identification of metabolically active methanogens in anaerobic digester by DNA Stable-Isotope Probing using 13C-acetate

    Directory of Open Access Journals (Sweden)

    V. Gowdaman

    2015-04-01

    Full Text Available Anaerobic digestion is gaining enormous attention due to the ability to covert organic wastes into biogas, an alternative sustainable energy. Methanogenic community plays a significant role in biogas production and also for proficient functioning of the anaerobic digester. Therefore, this study was carried out to investigate the methanogen diversity of a food waste anaerobic digester. After endogenous respiration, the digester samples were supplemented with isotopes of acetate to enrich methanogen population, and were analyzed using DNA-SIP (Stable-Isotope Probing. Following separation and fractionation of heavy (13C and light (12C DNA, PCR amplification was carried out using archaeal 16S rRNA gene followed by DGGE analysis. Sequencing of the prominent DGGE bands revealed the dominance of Methanocorpusculum labreanum species belonging to hydrogenotrophic Methanomicrobiales, which can produce methane in the presence of H2/CO2 and requires acetate for its growth. This is the first instance where Methanocorpusculum labreanum is being reported as a dominant species in an anaerobic digester operative on food waste.

  10. [Effect of NH4(+) -N/NO3(-)-N ratio in applied supplementary fertilizer on nitrogen metabolism and main chemical composition of Pinellia ternata].

    Science.gov (United States)

    Hu, Long-Jiao; Wang, Kang-Cai; Li, Can-Wen

    2013-07-01

    To study the effect of nitrogen forms on nitrogen metabolism and main chemical composition of Pinellia ternate. Through the soilless cultivation experiment and based at the same nitrogen level and different NH4(+) -N/NO3(-) -N ratios, nitrate reductase (NR) activity, glutamine synthetase (GS) activity, the content of nitrate nitrogen and ammonium nitrogen in different parts of P. ternate were determined. The contents of total alkaloid, free total organic acids and guanosine in the tuber were determined. The yield of bulbil and tuber was calculated. The test results showed that, with the NH4(+) -N/NO3(-) -N ratio increasing, the activity of nitrate reductase decreased, the content of nitrate nitrogen in the leaves, petioles and tuber increasing initially, then decreased, and the content of nitrate nitrogen in the root decreased. Meanwhile, with the NH4(+) -N/NO3(-) -N ratio increasing, the activity of glutamine synthetase in the leaves, petioles and root increased, the activity of glutamine synthetase in the tuber increasing initially, then decreased. The contents of ammonium nitrogen in the leaves, tuber and root increased initially, then decreased, and the contents of ammonium nitrogen in the petioles increased with the NH4(+)(-N/NO3(-)-N ratio increasing. The yield of bulbil and tuber were the highest at the NH4(+)-N/NO3(-) -N ratio of 75: 25. The content of total alkaloid and guanosine in the tuber were the highest at the NH4(+)-N/NO3(-) -N ratio of 0: 100, and the contents were 0.245% and 0.0197% respectively. With the NH4(+)-N/NO3(-) -N ratio of 50: 50, the content of free total organic acids was the highest, it reached 0.7%, however, the content of free total organic acids was the lowest at the NH4(+) -N/NO3(-) -N ratio of 0: 100. Nitrogen fertilization significant influences the nitrogen metabolism, the yield and main chemical composition of P. ternate.

  11. Effects of ruminal protein degradability and frequency of supplementation on nitrogen retention, apparent digestibility, and nutrient flux across visceral tissues in lambs fed low-quality forage.

    Science.gov (United States)

    Atkinson, R L; Toone, C D; Robinson, T J; Harmon, D L; Ludden, P A

    2010-02-01

    Two experiments were conducted to determine the effect of ruminal protein degradability and supplementation frequency on intake, apparent digestibility, N retention, and nutrient flux across visceral tissues of lambs fed a low-quality forage diet. In both experiments, wethers were fed a basal diet of mature crested wheatgrass hay (4.2% CP) for ad libitum consumption plus 1 of 4 supplements: 1) a high RDP supplement provided daily (RDP-D), 2) the high RDP supplement provided on alternate days (RDP-A), 3) a high RUP provided on alternate days (RUP-A), or 4) a 50:50 mixture of the RDP and RUP supplements provided on alternate days. In Exp. 1, 12 lambs (29.9 +/- 2.7 kg initial BW) were used. Forage OM, NDF, and ADF intake were not affected by treatment. Total tract digestibilities (OM, NDF, ADF, and N) were unaffected (P >or= 0.15) by treatment. Neither protein degradability nor supplementation frequency had an effect (P >or= 0.52) on N retention. In Exp. 2, 15 lambs (34 +/- 4 kg initial BW) fitted with indwelling catheters in a hepatic vein, the hepatic portal vein, a mesenteric vein, and a mesenteric artery were used. Release of ammonia N by the portal-drained viscera (PDV) was reduced (P = 0.004) in alternate-day-supplemented lambs compared with RDP-D. Consequently, hepatic uptake of ammonia N was least (P = 0.003) in all alternate-day lambs. Alpha-amino nitrogen (AAN) release by the PDV and hepatic uptake of AAN were not affected by treatment or supplementation frequency. Additionally, hepatic output and PDV uptake of urea N were not affected by treatment. Hepatic N uptake (ammonia N + AAN) accounted for urea synthesized by the liver in all treatments; however, hepatic urea synthesis was approximately 4.5-fold less for RUP-A lambs. This suggests that the provision of AA as RUP may provide a delay in ureagenesis, thus altering the timing of N recycling.

  12. Biochar from swine manure solids: influence on carbon sequestration and Olsen phosphorus and mineral nitrogen dynamics in soil with and without digestate incorporation

    Directory of Open Access Journals (Sweden)

    Rosa Marchetti

    2012-05-01

    Full Text Available Interest in biochar (BC has grown dramatically in recent years, due mainly to the fact that its incorporation into soil reportedly enhances carbon sequestration and fertility. Currently, BC types most under investigation are those obtained from organic matter (OM of plant origin. As great amounts of manure solids are expected to become available in the near future, thanks to the development of technologies for the separation of the solid fraction of animal effluents, processing of manure solids for BC production seems an interesting possibility for the recycling of OM of high nutrient value. The aim of this study was to investigate carbon (C sequestration and nutrient dynamics in soil amended with BC from dried swine manure solids. The experiment was carried out in laboratory microcosms on a silty clay soil. The effect on nutrient dynamics of interaction between BC and fresh digestate obtained from a biogas plant was also investigated to test the hypothesis that BC can retain nutrients. A comparison was made of the following treatments: soil amended with swine manure solids (LC, soil amended with charred swine manure solids (LT, soil amended with wood chip (CC, soil amended with charred wood chip (CT, soil with no amendment as control (Cs, each one of them with and without incorporation of digestate (D for a total of 10 treatments. Biochar was obtained by treating OM (wood chip or swine manure with moisture content of less than 10% at 420°C in anoxic conditions. The CO2-C release and organic C, available phosphorus (P (Olsen P, POls and inorganic (ammonium+nitrate nitrogen (N (Nmin contents at the start and three months after the start of the experiment were measured in the amended and control soils. After three months of incubation at 30°C, the CO2-C emissions from soil with BC (CT and LT, ±D were the same as those in the control soil (Cs and were lower than those in the soils with untreated amendments (CC and LC, ±D. The organic C content

  13. Polyol synthesis in Aspergillus niger : influence of oxygen availability, carbon and nitrogen sources on the metabolism

    DEFF Research Database (Denmark)

    Diano, Audrey; Bekker-Jensen, S; Dynesen, Jens Østergaard

    2006-01-01

    Polyol production has been studied in Aspergillus niger under different conditions. Fermentations have been run using high concentration of glucose or xylose as carbon source and ammonium or nitrate as nitrogen source. The growth of biomass, as freely dispersed hyphae, led to an increase of medium...

  14. Role of ureolytic activity in Bacillus cereus nitrogen metabolism and acid survival

    NARCIS (Netherlands)

    Mols, J.M.; Abee, T.

    2008-01-01

    The presence and activities of urease genes were investigated in 49 clinical, food, and environmental Bacillus cereus isolates. Ten strains were shown to have urease genes, with eight of these strains showing growth on urea as the sole nitrogen source. Two of the urease-positive strains, including

  15. Ammonia stress on nitrogen metabolism in tolerant aquatic plant-Myriophyllum aquaticum.

    Science.gov (United States)

    Zhou, Qingyang; Gao, Jingqing; Zhang, Ruimin; Zhang, Ruiqin

    2017-09-01

    Ammonia has been a major reason of macrophyte decline in the water environment, and ammonium ion toxicity should be seen as universal, even in species frequently labeled as "NH 4 + specialists". To study the effects of high NH 4 + -N stress of ammonium ion nitrogen on tolerant submerged macrophytes and investigate the pathways of nitrogen assimilation in different organisms, Myriophyllum aquaticum was selected and treated with various concentrations of ammonium ions at different times. Increasing of ammonium concentration leads to an overall increase in incipient ammonia content in leaves and stems of plants. In middle and later stages, high concentrations of NH 4 + ion nitrogen taken up by M. aquaticum decreased, whereas the content of NO 3 - ion nitrogen increased. Moreover, in M. aquaticum, the activities of the enzymes nitrate reductase, glutamine synthetase and asparagine synthetase changed remarkably in the process of alleviating NH 4 + toxicity and deficiency. The results of the present study may support the studies on detoxification of high ammonium ion content in NH 4 + -tolerant submerged macrophytes and exploration of tissue-specific expression systems. Copyright © 2017. Published by Elsevier Inc.

  16. Carbon and nitrogen metabolism of free-living Frankia spp. and of Frankia-alnus symbioses

    NARCIS (Netherlands)

    Blom, J.

    1982-01-01

    The research reported in this thesis deals with the symbiosis of Frankia spp. and Alnus glutinosa. Frankia spp. are actinomycetes giving rise to the formation of nitrogen-fixing nodules on the roots of a number of non-leguminous plants. In these nodules

  17. EFFECTIVENESS OF NITROGEN-CONTAINING BISPHOSPHONATES IN THE REGULATION OF MINERAL METABOLISM DISTURBANCES ASSOCIATED WITH ALIMENTARY OSTEOPOROSIS IN RATS

    Directory of Open Access Journals (Sweden)

    Komisarenko S. V.

    2015-08-01

    Full Text Available The aim of the study was to investigate the effectiveness of nitrogen-containing bisphosphonates synthesized as promising substances for correction of mineral metabolism in osteoporosis. The study was carried out on a model of alimentary osteoporosis that was characterized by hypocalcaemia, hypophosphatemia, decreased 25-Hydroxyvitamin D3 content in blood serum and severe bone tissue demineralization (reduced ash content and mineral components. It was found that synthesized novel nitrogen bisphosphonates (pyrazole-containing analogues, like reference drugs — metylene bisphosphonate (disodium salt of metylene bisphosphonic acid and alendronate (4-amino-1-hidroxybutyliden bisphosphonate, inhibit with the different efficiency demineralization of the bone tissue and increase the mineral metabolism in rats with alimentary (nutritional osteoporosis that was assessed by the marker parameters of bone formation. In particular, drug administration (bisphosphonates І-12, І-40, І-42 resulted in elevation of calcium and phosphate levels and decreased the total activity of alkaline phosphatase and its isoenzymes in blood serum. The ash content and the levels of calcium and phosphorus in the ash of tibia and femur bones were shown to be markedly elevated. Bisphosphonate І-12 has shown more profound antiresorbtive activity and ability to correct mineral metabolism in alimentary osteoporosis, including such of reference drugs. It was found a significant decrease of 25-Hydroxyvitamin D3 content in the serum that is considered as a profound vitamin D3 deficiency associated with nutritional osteoporosis. As it was not compensated by bisphosphonates, we suggest that further investigations should be directed to the combined use of both: bisphosphonates as inhibitors of osteoclast activity that diminish bone resorption and vitamin D3 as a key regulator of bone remodeling process and osteosynthesis activator.

  18. Comparison of ion balance and nitrogen metabolism in old and young leaves of alkali-stressed rice plants.

    Science.gov (United States)

    Wang, Huan; Wu, Zhihai; Han, Jiayu; Zheng, Wei; Yang, Chunwu

    2012-01-01

    Alkali stress is an important agricultural contaminant and has complex effects on plant metabolism. The aim of this study was to investigate whether the alkali stress has different effects on the growth, ion balance, and nitrogen metabolism in old and young leaves of rice plants, and to compare functions of both organs in alkali tolerance. The results showed that alkali stress only produced a small effect on the growth of young leaves, whereas strongly damaged old leaves. Rice protected young leaves from ion harm via the large accumulation of Na(+) and Cl(-) in old leaves. The up-regulation of OsHKT1;1, OsAKT1, OsHAK1, OsHAK7, OsHAK10 and OsHAK16 may contribute to the larger accumulation of Na(+) in old leaves under alkali stress. Alkali stress mightily reduced the NO(3)(-) contents in both organs. As old leaf cells have larger vacuole, under alkali stress these scarce NO(3)(-) was principally stored in old leaves. Accordingly, the expression of OsNRT1;1 and OsNRT1;2 in old leaves was up-regulated by alkali stress, revealing that the two genes might contribute to the accumulation of NO(3)(-) in old leaves. NO(3)(-) deficiency in young leaves under alkali stress might induce the reduction in OsNR1 expression and the subsequent lacking of NH(4)(+), which might be main reason for the larger down-regulation of OsFd-GOGAT and OsGS2 in young leaves. Our results strongly indicated that, during adaptation of rice to alkali stress, young and old leaves have distinct mechanisms of ion balance and nitrogen metabolism regulation. We propose that the comparative studies of young and old tissues may be important for abiotic stress tolerance research.

  19. Roostocks/scion/ nitrogen interactions affect secondary metabolism in the grape berry

    Directory of Open Access Journals (Sweden)

    Aude Habran

    2016-08-01

    Full Text Available ABSTRACT : The present work investigates the interactions between soil content, rootstock and scion by focusing on the effects of roostocks and nitrogen supply on grape berry content. Scions of Cabernet Sauvignon (CS and Pinot Noir (PN varieties were grafted either on Riparia Gloire de Montpellier (RGM or 110 Richter (110R rootstock. The 4 rooststock/scion combinations were fertilized with 3 different levels of nitrogen after fruit set. Both in 2013 and 2014, N supply increased N uptake by the plants, and N content both in vegetative and reproductory organs. Rootstock, variety and year affected berry weight at harvest, while nitrogen did not affect significantly this parameter. Grafting on RGM consistently increased berry weight compared to 110R. PN consistently produced bigger berries than CS. CS berries were heavier in 2014 than in 2013, but the year effect was less marked for PN berries. The berries were collected between veraison and maturity, separated in skin and pulp, and their content was analyzed by conventional analytical procedures and untargeted metabolomics. For anthocyanins, the relative quantitation was fairly comparable with both LC-MS determination and HPLC-DAD, which is a fully quantitative technique. The data show complex responses of the metabolite content (sugars, organic acids, amino acids, anthocyanins, flavonols, flavan-3-ols/procyanidins, stilbenes, hydroxycinnamic and hydroxybenzoic acids. that depend on the rootstock, the scion, the vintage, the nitrogen level, the berry compartment. This opens a wide range of possibilities to adjust the content of these compounds through the choice of the roostock, variety and nitrogen fertilization.

  20. Roostocks/Scion/Nitrogen Interactions Affect Secondary Metabolism in the Grape Berry.

    Science.gov (United States)

    Habran, Aude; Commisso, Mauro; Helwi, Pierre; Hilbert, Ghislaine; Negri, Stefano; Ollat, Nathalie; Gomès, Eric; van Leeuwen, Cornelis; Guzzo, Flavia; Delrot, Serge

    2016-01-01

    The present work investigates the interactions between soil content, rootstock, and scion by focusing on the effects of roostocks and nitrogen supply on grape berry content. Scions of Cabernet Sauvignon (CS) and Pinot Noir (PN) varieties were grafted either on Riparia Gloire de Montpellier (RGM) or 110 Richter (110R) rootstock. The 4 rooststock/scion combinations were fertilized with 3 different levels of nitrogen after fruit set. Both in 2013 and 2014, N supply increased N uptake by the plants, and N content both in vegetative and reproductory organs. Rootstock, variety and year affected berry weight at harvest, while nitrogen did not affect significantly this parameter. Grafting on RGM consistently increased berry weight compared to 110R. PN consistently produced bigger berries than CS. CS berries were heavier in 2014 than in 2013, but the year effect was less marked for PN berries. The berries were collected between veraison and maturity, separated in skin and pulp, and their content was analyzed by conventional analytical procedures and untargeted metabolomics. For anthocyanins, the relative quantitation was fairly comparable with both LC-MS determination and HPLC-DAD, which is a fully quantitative technique. The data show complex responses of the metabolite content (sugars, organic acids, amino acids, anthocyanins, flavonols, flavan-3-ols/procyanidins, stilbenes, hydroxycinnamic, and hydroxybenzoic acids) that depend on the rootstock, the scion, the vintage, the nitrogen level, the berry compartment. This opens a wide range of possibilities to adjust the content of these compounds through the choice of the roostock, variety and nitrogen fertilization.

  1. Importance of molybdenum in the nitrogen metabolism of microorganisms and higher plants

    Energy Technology Data Exchange (ETDEWEB)

    Mulder, E G

    1948-01-01

    The effect of molybdenum on the growth of microorganisms and higher plants and on some well-defined biochemical reactions was investigated. Results indicate that Aspergillus niger requires small amounts of molybdenum when growing in a culture solution supplied with nitrate nitrogen. With ammonium sulfate as a source of nitrogen, the response of the fungus to molybdenum was much smaller. It was shown that this different response of Aspergillus to molybdenum was not brought about by a difference in purity of both nitrogen compounds used, nor by a difference in absorption of the molybdenum impurity, but by a considerably higher requirement of molybdenum in a medium with nitrate nitrogen. The growth-rate curve and the increasing sporulation of Aspergillus niger with increasing amounts of molybdenum were used in estimating very small amounts of this element in various materials. In culture solution experiments with tomato, barley and oat plants the effect of traces of molybdenum on the growth of these plants was investigated. In good agreement with the results of the experiments with Aspergillus and denitrifying bacteria it could be shown that in the green plant as in these microorganisms molybdenum is acting as a catalyst in nitrate reduction. In experiments with Azotobacter chroococcum and leguminous plants the effect of molybdenum on the fixation of gaseous N/sub 2/ was studied. In culture solutions with pea plants the effect of molybdenum on the nitrogen fixation of the nodules was investigated. In the absence of molybdenum as well as in a complete nutrient medium many nodules were formed. 30 references, 6 figures, 16 tables.

  2. Evidence for increasing digestive and metabolic efficiency of energy utilization with age of dairy cattle as determined in two feeding regimes.

    Science.gov (United States)

    Grandl, F; Zeitz, J O; Clauss, M; Furger, M; Kreuzer, M; Schwarm, A

    2018-03-01

    The changes taking place with age in energy turnover of dairy cattle are largely unknown. It is unclear whether the efficiency of energy utilization in digestion (characterized by faecal and methane energy losses) and in metabolism (characterized by urine and heat energy losses) is altered with age. In the present study, energy balance data were obtained from 30 lactating Brown Swiss dairy cows aged between 2 and 10 years, and 12 heifers from 0.5 to 2 years of age. In order to evaluate a possible dependence of age effects on diet type, half of the cattle each originated from two herds kept at the same farm, which were fed either on a forage-only diet or on the same forage diet but complemented with 5 kg/day of concentrate since their first calving. During 2 days, the gaseous exchange of the animals was quantified in open-circuit respiration chambers, followed by an 8-day period of feed, faeces, urine and milk collection. Daily amounts and energy contents were used to calculate complete energy balances. Age and feeding regime effects were analysed by parametric regression analysis where BW, milk yield and hay proportion in forage as consumed were considered as covariates. Relative to intake of gross energy, the availability of metabolizable energy (ME) increased with age. This was not the result of an increasing energy digestibility, but of proportionately lower energy losses with methane (following a curvilinear relationship with the greatest losses in middle-aged cows) and urine (continuously declining). The efficiency of utilization of ME for milk production (k l) increased with age. Potential reasons include an increase in the propionate-to-acetate ratio in the rumen because of a shift away from fibre degradation and methane formation as well as lower urine energy losses. The greater k l allowed older cows to accrete more energy reserves in the body. As expected, offering concentrate enhanced digestibility, metabolizability and metabolic utilization of energy

  3. Magnitude Differences in Bioactive Compounds, Chemical Functional Groups, Fatty Acid Profiles, Nutrient Degradation and Digestion, Molecular Structure, and Metabolic Characteristics of Protein in Newly Developed Yellow-Seeded and Black-Seeded Canola Lines.

    Science.gov (United States)

    Theodoridou, Katerina; Zhang, Xuewei; Vail, Sally; Yu, Peiqiang

    2015-06-10

    Recently, new lines of yellow-seeded (CS-Y) and black-seeded canola (CS-B) have been developed with chemical and structural alteration through modern breeding technology. However, no systematic study was found on the bioactive compounds, chemical functional groups, fatty acid profiles, inherent structure, nutrient degradation and absorption, or metabolic characteristics between the newly developed yellow- and black-seeded canola lines. This study aimed to systematically characterize chemical, structural, and nutritional features in these canola lines. The parameters accessed include bioactive compounds and antinutrition factors, chemical functional groups, detailed chemical and nutrient profiles, energy value, nutrient fractions, protein structure, degradation kinetics, intestinal digestion, true intestinal protein supply, and feed milk value. The results showed that the CS-Y line was lower (P ≤ 0.05) in neutral detergent fiber (122 vs 154 g/kg DM), acid detergent fiber (61 vs 99 g/kg DM), lignin (58 vs 77 g/kg DM), nonprotein nitrogen (56 vs 68 g/kg DM), and acid detergent insoluble protein (11 vs 35 g/kg DM) than the CS-B line. There was no difference in fatty acid profiles except C20:1 eicosenoic acid content (omega-9) which was in lower in the CS-Y line (P structure spectral profile, there were no significant differences in functional groups of amides I and II, α helix, and β-sheet structure as well as their ratio between the two new lines, indicating no difference in protein structure makeup and conformation between the two lines. In terms of energy values, there were significant differences in total digestible nutrient (TDN; 149 vs 133 g/kg DM), metabolizable energy (ME; 58 vs 52 MJ/kg DM), and net energy for lactation (NEL; 42 vs 37 MJ/kg DM) between CS-Y and CS-B lines. For in situ rumen degradation kinetics, the two lines differed in soluble fraction (S; 284 vs 341 g/kg CP), potential degradation fraction (D; 672 vs 590 g/kg CP), and effective degraded

  4. Effects of the Dietary Probiotic Clostridium butyricum on Intestine Digestive and Metabolic Capacities, SCFA Content and Body Composition in Marsupenaeus japonicus

    Science.gov (United States)

    Duan, Yafei; Dong, Hongbiao; Wang, Yun; Zhang, Yue; Zhang, Jiasong

    2018-06-01

    A 56-day feeding trial was performed to evaluate the effects of dietary probiotic Clostridium butyricum (CB) on intestine digestive and metabolic capacities, intestine short-chain fatty acids (SCFA) content and body composition of kuruma shrimp Marsupenaeus japonicus. Shrimps were randomly allocated into 9 tanks, 30 each, and fed with diets containing different levels of C. butyricum (1 × 109 cfu g-1): 0 mg g-1 feed (Control), 100 mg g-1 feed (CB-100), 200 mg g-1 feed (CB-200), while each level was triplicated. The results indicated that compared with the control group, the intestine pepsin (Pep) activity and 5-hydroxytryptamine (5-HT) concentration of two C. butyricum groups were both increased. Amylase (AMY) and lipase (LPS) activities were only induced in CB-200 group. Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities of two C. butyricum groups showed no significant change. The α-amylase (AMY) gene expression was induced in CB-200 group, and trypsin gene expression of two C. butyricum treated groups were both induced. Intestine SCFA content and body composition analysis showed that the contents of propionic acid, butyric acid and the crude protein of two C. butyricum groups were all higher than those of control. These results revealed that C. butyricum can modulate intestine digestive and metabolic capacities, improve intestine SCFA content and body crude protein content in M. japonicus.

  5. Macroalgae δ15N values in well-mixed estuaries: Indicator of anthropogenic nitrogen input or macroalgae metabolism?

    Science.gov (United States)

    Raimonet, Mélanie; Guillou, Gaël; Mornet, Françoise; Richard, Pierre

    2013-03-01

    Although nitrogen stable isotope ratio (δ15N) in macroalgae is widely used as a bioindicator of anthropogenic nitrogen inputs to the coastal zone, recent studies suggest the possible role of macroalgae metabolism in δ15N variability. Simultaneous determinations of δ15N of dissolved inorganic nitrogen (DIN) along the land-sea continuum, inter-species variability of δ15N and its sensitivity to environmental factors are necessary to confirm the efficiency of macroalgae δ15N in monitoring nitrogen origin in mixed-use watersheds. In this study, δ15N of annual and perennial macroalgae (Ulva sp., Enteromorpha sp., Fucus vesiculosus and Fucus serratus) are compared to δ15N-DIN along the Charente Estuary, after characterizing δ15N of the three main DIN sources (i.e. cultivated area, pasture, sewage treatment plant outlet). During late winter and spring, when human activities produce high DIN inputs, DIN sources exhibit distinct δ15N signals in nitrate (NO) and ammonium (NH): cultivated area (+6.5 ± 0.6‰ and +9.0 ± 11.0‰), pasture (+9.2 ± 1.8‰ and +12.4‰) and sewage treatment plant discharge (+16.9 ± 8.7‰ and +25.4 ± 5.9‰). While sources show distinct δN- in this multiple source catchment, the overall mixture of NO sources - generally >95% DIN - leads to low variations of δN-NO at the mouth of the estuary (+7.7 to +8.4‰). Even if estuarine δN-NO values are not significantly different from pristine continental and oceanic site (+7.3‰ and +7.4‰), macroalgae δ15N values are generally higher at the mouth of the estuary. This highlights high anthropogenic DIN inputs in the estuary, and enhanced contribution of 15N-depleted NH in oceanic waters. Although seasonal variations in δN-NO are low, the same temporal trends in macroalgae δ15N values at estuarine and oceanic sites, and inter-species differences in δ15N values, suggest that macroalgae δ15N values might be modified by the metabolic response of macroalgae to environmental parameters (e

  6. Root-to-seed transport and metabolism of fixed nitrogen in soybean

    International Nuclear Information System (INIS)

    McClure, P.R.

    1983-01-01

    The great energetic demand of nitrogen fixation to support growth of the exceptionally high-N seeds is certainly a major yield barrier for soybeans. Transport of carbohydrate energy supplies to the root and of fixed nitrogen (N) from the root appear to contribute to the yield barrier, also. N is loaded into the soybean xylem stream principally as allantoin (ALL), and allantonic acid (ALLA), but xylem carries only dilute N and cannot reach the seeds at sufficient rate to support their N needs. Explants consisting of stem and a few leaves and pods were allowed to take up 14 C- and/or 15 N-ALL/ALLA in synthetic xylem sap. The 14 C label was found to become fairly quantitatively immobilized in leaves. The N (and 15 N label) almost certainly is separated from the C( 14 C label) at this time

  7. Effect of carbon/nitrogen ratio on carbohydrate metabolism and light energy dissipation mechanisms in Arabidopsis thaliana.

    Science.gov (United States)

    Huarancca Reyes, Thais; Scartazza, Andrea; Lu, Yu; Yamaguchi, Junji; Guglielminetti, Lorenzo

    2016-08-01

    Carbon (C) and nitrogen (N) nutrient sources are essential elements for metabolism, and their availability must be tightly coordinated for the optimal growth and development in plants. Plants are able to sense and respond to different C/N conditions via specific partitioning of C and N sources and the regulation of a complex cellular metabolic activity. We studied how the interaction between C and N signaling could affect carbohydrate metabolism, soluble sugar levels, photochemical efficiency of photosystem II (PSII) and the ability to drive the excess energy in Arabidopsis seedlings under moderated and disrupted C/N-nutrient conditions. Invertase and sucrose synthase activities were markedly affected by C/N-nutrient status depending on the phosphorylation status, suggesting that these enzymes may necessarily be modulated by their direct phosphorylation or phosphorylation of proteins that form complex with them in response to C/N stress. In addition, the enzymatic activity of these enzymes was also correlated with the amount of sugars, which not only act as substrate but also as signaling compounds. Analysis of chlorophyll fluorescence in plants under disrupted C/N condition suggested a reduction of electron transport rate at PSII level associated with a higher capacity for non-radiative energy dissipation in comparison with plants under moderated C/N condition. In conclusion, the tight coordination between C and N not only affects the carbohydrates metabolism and their concentration within plant tissues, but also the partitioning of the excitation energy at PSII level between radiative (electron transport) and non-radiative (heat) dissipation pathways. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  8. Milk production, nutrient digestibility and nitrogen balance in lactating cows fed total mixed ration silages containing steam-flaked brown rice as substitute for steam-flaked corn, and wet food by-products.

    Science.gov (United States)

    Miyaji, Makoto; Matsuyama, Hiroki; Hosoda, Kenji; Nonaka, Kazuhisa

    2013-06-01

    The objective of this study was to evaluate the effect of substituting brown rice grain for corn grain in total mixed ration (TMR) silage containing food by-products on the milk production, whole-tract nutrient digestibility and nitrogen balance in dairy cows. Six multiparous Holstein cows were used in a crossover design with two dietary treatments: a diet containing 30.9% steam-flaked corn (corn TMR) or 30.9% steam-flaked brown rice (rice TMR) with wet soybean curd residue and wet soy sauce cake. Dietary treatment did not affect the dry matter intake, milk yield and compositions in dairy cows. The dry matter and starch digestibility were higher, and the neutral detergent fiber digestibility was lower for rice TMR than for corn TMR. The urinary nitrogen (N) excretion as a proportion of the N intake was lower for rice TMR than for corn TMR with no dietary effect on N secretion in milk and fecal N excretion. These results indicated that the replacement of corn with brown rice in TMR silage relatively reduced urinary N loss without adverse effects on feed intake and milk production, when food by-products such as soybean curd residue were included in the TMR silage as dietary crude protein sources. © 2013 Japanese Society of Animal Science.

  9. Metabolomics Reveals Cryptic Interactive Effects of Species Interactions and Environmental Stress on Nitrogen and Sulfur Metabolism in Seagrass

    DEFF Research Database (Denmark)

    Hasler-Sheetal, Harald; Castorani, Max C. N.; Glud, Ronnie N.

    2016-01-01

    Eutrophication of estuaries and coastal seas is accelerating, increasing light stress on subtidal marine plants and changing their interactions with other species. To date, we have limited understanding of how such variations in environmental and biological stress modify the impact of interactions...... among foundational species and eventually affect ecosystem health. Here, we used metabolomics to assess the impact of light reductions on interactions between the seagrass Zostera marina, an important habitat-forming marine plant, and the abundant and commercially important blue mussel Mytilus edulis....... Plant performance varied with light availability but was unaffected by the presence of mussels. Metabolomic analysis, on the other hand, revealed an interaction between light availability and presence of M. edulis on seagrass metabolism. Under high light, mussels stimulated seagrass nitrogen and energy...

  10. Interactive effects of UV-B irradiation and triadimefon on nodulation and nitrogen metabolism in Vigna radiata plants

    International Nuclear Information System (INIS)

    Rajendiran, K.; Ramanujam, M.P.

    2006-01-01

    Supply of aqueous solution of triadimefon (20 mg/cubic dm) to unstressed green gram plants increased the contents of soluble proteins, amino acids, nitrate and nitrite, and the activity of nitrate reductase in the leaves and nitrate reductase in nodules. The nitrogenase activity in nodules and roots was also increased. Number and fresh mass of nodules and their nitrate and nitrite contents were also higher than those of the controls. In contrast, the UV-B stress (12.2 kJ/square m/d) suppressed nodulation and nitrogen metabolism in leaves and roots in comparison with plants under natural UV-B (10 kJ/square m/d). Triadimefon-treated plants did not show such severe inhibitions after exposure to elevated UV-B. Thus, triadimefon increased their tolerance to UV-B stress

  11. Responses of nitrogen metabolism and seed nutrition to drought stress in soybean genotypes differing in slow-wilting phenotype

    Directory of Open Access Journals (Sweden)

    Nacer eBellaloui

    2013-12-01

    Full Text Available Recent advances in soybean breeding have resulted in genotypes that express the slow-wilting phenotype (trait under drought stress conditions. The physiological mechanisms of this trait remain unknown due to the complexity of trait × environment interactions. The objective of this research was to investigate nitrogen metabolism and leaf and seed nutrients composition of the slow-wilting soybean genotypes under drought stress conditions. A repeated greenhouse experiment was conducted using check genotypes: NC-Roy (fast wilting, Boggs (intermediate in wilting; and NTCPR94-5157 and N04-9646 (slow-wilting, SLW genotypes. Plants were either well-watered or drought stressed. Results showed that under well-watered conditions, nitrogen fixation (NF, nitrogen assimilation (NA, and leaf and seed composition differed between genotypes. Under drought stress, NF and NA were higher in NTCPR94-5157 and N04-9646 than in NC-Roy and Boggs. Under severe water stress, however, NA was low in all genotypes. Leaf water potential was significantly lower in checks (-2.00 MPa than in the SLW genotypes (-1.68 MPa. Leaf and seed concentrations of K, P, Ca, Cu, Na, B were higher in SLW genotypes than in the checks under drought stress conditions. Seed protein, oleic acid, and sugars were higher in SLW genotypes, and oil, linoleic and linolenic acids were lower in SLW genotypes. This research demonstrated that K, P, Ca, Cu, Na, and B may be involved in SLW trait by maintaining homeostasis and osmotic regulation. Maintaining higher leaf water potential in NTCPR94-5157 and N04-9646 under drought stress could be a possible water conservation mechanism to maintain leaf turgor pressure. The increase in osmoregulators such as minerals, raffinose and stachyose, and oleic acid could be beneficial for soybean breeders in selecting for drought stress tolerance.

  12. Understanding the interplay of carbon and nitrogen supply for ectoines production and metabolic overflow in high density cultures of Chromohalobacter salexigens.

    Science.gov (United States)

    Salar-García, María J; Bernal, Vicente; Pastor, José M; Salvador, Manuel; Argandoña, Montserrat; Nieto, Joaquín J; Vargas, Carmen; Cánovas, Manuel

    2017-02-08

    The halophilic bacterium Chromohalobacter salexigens has been proposed as promising cell factory for the production of the compatible solutes ectoine and hydroxyectoine. This bacterium has evolved metabolic adaptations to efficiently grow under high salt concentrations by accumulating ectoines as compatible solutes. However, metabolic overflow, which is a major drawback for the efficient conversion of biological feedstocks, occurs as a result of metabolic unbalances during growth and ectoines production. Optimal production of ectoines is conditioned by the interplay of carbon and nitrogen metabolisms. In this work, we set out to determine how nitrogen supply affects the production of ectoines. Chromohalobacter salexigens was challenged to grow in media with unbalanced carbon/nitrogen ratio. In C. salexigens, overflow metabolism and ectoines production are a function of medium composition. At low ammonium conditions, the growth rate decreased importantly, up to 80%. Shifts in overflow metabolism were observed when changing the C/N ratio in the culture medium. 13 C-NMR analysis of ectoines labelling revealed a high metabolic rigidity, with almost constant flux ratios in all conditions assayed. Unbalanced C/N ratio led to pyruvate accumulation, especially upon N-limitation. Analysis of an ect - mutant demonstrated the link between metabolic overflow and ectoine biosynthesis. Under non ectoine synthesizing conditions, glucose uptake and metabolic overflow decreased importantly. Finally, in fed-batch cultures, biomass yield was affected by the feeding scheme chosen. High growth (up to 42.4 g L -1 ) and volumetric ectoine yields (up to 4.21 g L -1 ) were obtained by minimizing metabolite overflow and nutrient accumulation in high density cultures in a low nitrogen fed-batch culture. Moreover, the yield coefficient calculated for the transformation of glucose into biomass was 30% higher in fed-batch than in the batch culture, demonstrating that the metabolic

  13. Nitrogen acquisition, transport and metabolism in intact ectomycorrhizal associations studied by 15N stable isotope techniques

    International Nuclear Information System (INIS)

    Ek, H.

    1993-05-01

    The focus of this thesis is on the external mycelium and its role in nitrogen uptake, assimilation and translocation. Tree seedlings in association with ectomycorrhizal fungi were grown in observation chambers. The fungal mycelium were fed with 15-N ammonium or 15-N nitrate or a combination of both. The effects of Collembola on the ectomycorrhizal symbiosis were also studied. The results demonstrates an important role of the external mycelium of Paxillus involutus not only in the uptake but also in the assimilation of ammonium into a variety of different amino acids, primarily glutamine but also glutamic acid, aspartic acid, and alanine, immediately after uptake. The results indicate that ammonium is assimilated by GS and GOGAT or GDH in the mycelium at the uptake site. When nitrate was added to the mycelium as the sole nitrogen source nitrate was reduced in the mycelium and the product assimilated into amino acids. When ammonium nitrate was supplied to the fungal mycelium nitrate was taken up the fungus and transferred to the plant, however, apparently no assimilation of nitrate occurred in the external mycelium. Ammonium or an assimilation product, such as glutamine, probably represses nitrate reductase (NR) but not nitrate uptake and transfer in P. involutus. P. involutus nitrogen uptake and transfer to the associated mycorrhizal pine was up to 76% higher when low numbers of the Collembola Onychiurus armatus were present compared to when they were completely absent. This was probably an indirect effect as P. involutus hyphal growth rate and extramatrical biomass increased at a low Collembola density. At high Collembola densities P. involutus hyphal growth rate was retarded. (74 refs.)

  14. Ruminal nitrogen metabolism in steers as affected by feed intake and dietary urea concentration

    International Nuclear Information System (INIS)

    Firkins, J.L.; Berger, L.L.; Merchen, N.R.; Fahey, G.C. Jr.; Mulvaney, R.L.

    1987-01-01

    Four multiple-cannulated steers (340 kg) were used in a 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments. Steers were fed a diet of 50% ground hay and 50% concentrate at two intakes (1.4 and 2.1% of BW), with urea and 15 N-enriched ammonium sulfate infused continuously into the rumen at .4 or 1.2% of diet DM. Ratios of purines and diaminopimelic acid-N to N in fluid-associated and particulate-associated bacteria and in protozoa were similar among treatments but were lower for protozoa than for bacteria. Diaminopimelic acid-N:N was higher for fluid-associated vs. particulate-associated bacteria. Enrichment of 15 N was similar between bacteria among treatments and was 30% lower for protozoa. Turnover rates of 15 N in bacteria, NH 3 N, and non-HN 3 N pools were faster for steers infused with 1.2 than those infused with .4% urea, indicating less efficient usage of ammonia with higher urea. A method is described to estimate the proportion of duodenal nitrogen comprising bacterial and protozoal nitrogen

  15. Zn-biofortification enhanced nitrogen metabolism and photorespiration process in green leafy vegetable Lactuca sativa L.

    Science.gov (United States)

    Barrameda-Medina, Yurena; Lentini, Marco; Esposito, Sergio; Ruiz, Juan M; Blasco, Begoña

    2017-04-01

    Excessive rates of nitrogen (N) fertilizers may result in elevated concentrations of nitrate (NO 3 - ) in plants. Considering that many programs of biofortification with trace elements are being performed, it has become important to study how the application of these elements affects plant physiology and, particularly, N utilization in leaf crops. The main objective of the present study was to determine whether the NO 3 - accumulation and the nitrogen use efficiency was affected by the application of different doses of Zn in Lactuca sativa plants. Zn doses in the range 80-100 µmol L -1 produced an increase in Zn concentration provoking a decrease of NO 3 - concentration and increase of the nitrate reductase, glutamine synthetase and aspartate aminotransferase activities, as well as the photorespiration processes. As result, we observed an increase in reduced N, total N concentration and N utilization efficiency. Consequently, at a dose of 80 µmol L -1 of Zn, the amino acid concentration increased significantly. Adequate Zn fertilization is an important critical player in lettuce, especially at a dose of 80 µmol L -1 of Zn, because it could result in an increase in the Zn concentration, a reduction of NO 3 - levels and an increase the concentration of essential amino acids, with all of them having beneficial properties for the human diet. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  16. Effect of graded inclusion of dietary soybean meal on nutrient digestibility, health, and metabolic indices of adult dogs.

    Science.gov (United States)

    Menniti, M F; Davenport, G M; Shoveller, A K; Cant, J P; Osborne, V R

    2014-05-01

    Two studies were conducted using adult dogs to evaluate the effect of increasing the inclusion of soybean meal (SBM) in an adult dog food on body composition, hematological and biochemical blood analyses, and total tract nutrient digestibility. Nutritionally complete and balanced diets were formulated with commercial-grade SBM (48% CP) to replace 0, 10, 20, or 30% of the protein provided by dried chicken protein resulting in final SBM inclusion of 0, 6.0, 11.5, and 17.0% (as-fed basis), respectively. In study 1, diets were fed during a 24-wk feeding trial using 36 female (spayed), adult hounds to evaluate food intake, BW, body composition, and blood measurements. There were no diet-related differences in food intake or BW. Body composition responded in a quadratic manner to increased dietary SBM inclusion with the percentage (%) of lean mass responding positively (P dogs. Serum concentrations of C-reactive protein and IGF-1 were similar among diets. In study 2, diets were evaluated in a digestibility study using 12 adult dogs in a 4 × 4 Latin square design. Increased SBM inclusion was associated with linear increases in the digestibility of CP (P dogs.

  17. Long-term trends of changes in pine and oak foliar nitrogen metabolism in response to chronic nitrogen amendments at Harvard Forest, MA.

    Science.gov (United States)

    Minocha, Rakesh; Turlapati, Swathi A; Long, Stephanie; McDowell, William H; Minocha, Subhash C

    2015-08-01

    We evaluated the long-term (1995-2008) trends in foliar and sapwood metabolism, soil solution chemistry and tree mortality rates in response to chronic nitrogen (N) additions to pine and hardwood stands at the Harvard Forest Long Term Ecological Research (LTER) site. Common stress-related metabolites like polyamines (PAs), free amino acids (AAs) and inorganic elements were analyzed for control, low N (LN, 50 kg NH4NO3 ha(-1) year(-1)) and high N (HN, 150 kg NH4NO3 ha(-1) year(-1)) treatments. In the pine stands, partitioning of excess N into foliar PAs and AAs increased with both N treatments until 2002. By 2005, several of these effects on N metabolites disappeared for HN, and by 2008 they were mostly observed for LN plot. A significant decline in foliar Ca and P was observed mostly with HN for a few years until 2005. However, sapwood data actually showed an increase in Ca, Mg and Mn and no change in PAs in the HN plot for 2008, while AAs data revealed trends that were generally similar to foliage for 2008. Concomitant with these changes, mortality data revealed a large number of dead trees in HN pine plots by 2002; the mortality rate started to decline by 2005. Oak trees in the hardwood plot did not exhibit any major changes in PAs, AAs, nutrients and mortality rate with LN treatment, indicating that oak trees were able to tolerate the yearly doses of 50 kg NH4NO3 ha(-1) year(-1). However, HN trees suffered from physiological and nutritional stress along with increased mortality in 2008. In this case also, foliar data were supported by the sapwood data. Overall, both low and high N applications resulted in greater physiological stress to the pine trees than the oaks. In general, the time course of changes in metabolic data are in agreement with the published reports on changes in soil chemistry and microbial community structure, rates of soil carbon sequestration and production of woody biomass for this chronic N study. This correspondence of selected metabolites

  18. Relationship between ammonia stomatal compensation point and nitrogen metabolism in arable crops: Current status of knowledge and potential modelling approaches

    Energy Technology Data Exchange (ETDEWEB)

    Massad, Raia Silvia [Institut National de la Recherche Agronomique (INRA), Environnement et Grandes Cultures, 78850 Thiverval-Grignon (France)], E-mail: massad@grignon.inra.fr; Loubet, Benjamin; Tuzet, Andree; Cellier, Pierre [Institut National de la Recherche Agronomique (INRA), Environnement et Grandes Cultures, 78850 Thiverval-Grignon (France)

    2008-08-15

    The ammonia stomatal compensation point of plants is determined by leaf temperature, ammonium concentration ([NH{sub 4}{sup +}]{sub apo}) and pH of the apoplastic solution. The later two depend on the adjacent cells metabolism and on leaf inputs and outputs through the xylem and phloem. Until now only empirical models have been designed to model the ammonia stomatal compensation point, except the model of Riedo et al. (2002. Coupling soil-plant-atmosphere exchange of ammonia with ecosystem functioning in grasslands. Ecological Modelling 158, 83-110), which represents the exchanges between the plant's nitrogen pools. The first step to model the ammonia stomatal compensation point is to adequately model [NH{sub 4}{sup +}]{sub apo}. This [NH{sub 4}{sup +}]{sub apo} has been studied experimentally, but there are currently no process-based quantitative models describing its relation to plant metabolism and environmental conditions. This study summarizes the processes involved in determining the ammonia stomatal compensation point at the leaf scale and qualitatively evaluates the ability of existing whole plant N and C models to include a model for [NH{sub 4}{sup +}]{sub apo}. - A model for ammonia stomatal compensation point at the leaf level scale was developed.

  19. Relationship between ammonia stomatal compensation point and nitrogen metabolism in arable crops: Current status of knowledge and potential modelling approaches

    International Nuclear Information System (INIS)

    Massad, Raia Silvia; Loubet, Benjamin; Tuzet, Andree; Cellier, Pierre

    2008-01-01

    The ammonia stomatal compensation point of plants is determined by leaf temperature, ammonium concentration ([NH 4 + ] apo ) and pH of the apoplastic solution. The later two depend on the adjacent cells metabolism and on leaf inputs and outputs through the xylem and phloem. Until now only empirical models have been designed to model the ammonia stomatal compensation point, except the model of Riedo et al. (2002. Coupling soil-plant-atmosphere exchange of ammonia with ecosystem functioning in grasslands. Ecological Modelling 158, 83-110), which represents the exchanges between the plant's nitrogen pools. The first step to model the ammonia stomatal compensation point is to adequately model [NH 4 + ] apo . This [NH 4 + ] apo has been studied experimentally, but there are currently no process-based quantitative models describing its relation to plant metabolism and environmental conditions. This study summarizes the processes involved in determining the ammonia stomatal compensation point at the leaf scale and qualitatively evaluates the ability of existing whole plant N and C models to include a model for [NH 4 + ] apo . - A model for ammonia stomatal compensation point at the leaf level scale was developed

  20. The Glycerate and Phosphorylated Pathways of Serine Synthesis in Plants: The Branches of Plant Glycolysis Linking Carbon and Nitrogen Metabolism.

    Science.gov (United States)

    Igamberdiev, Abir U; Kleczkowski, Leszek A

    2018-01-01

    Serine metabolism in plants has been studied mostly in relation to photorespiration where serine is formed from two molecules of glycine. However, two other pathways of serine formation operate in plants and represent the branches of glycolysis diverging at the level of 3-phosphoglyceric acid. One branch (the glycerate - serine pathway) is initiated in the cytosol and involves glycerate formation from 3-phosphoglycerate, while the other (the phosphorylated serine pathway) operates in plastids and forms phosphohydroxypyruvate as an intermediate. Serine formed in these pathways becomes a precursor of glycine, formate and glycolate accumulating in stress conditions. The pathways can be linked to GABA shunt via transamination reactions and via participation of the same reductase for both glyoxylate and succinic semialdehyde. In this review paper we present a hypothesis of the regulation of redox balance in stressed plant cells via participation of the reactions associated with glycerate and phosphorylated serine pathways. We consider these pathways as important processes linking carbon and nitrogen metabolism and maintaining cellular redox and energy levels in stress conditions.

  1. Foliar nitrogen metabolism of adult Douglas-fir trees is affected by soil water availability and varies little among provenances.

    Science.gov (United States)

    Du, Baoguo; Kreuzwieser, Jürgen; Dannenmann, Michael; Junker, Laura Verena; Kleiber, Anita; Hess, Moritz; Jansen, Kirstin; Eiblmeier, Monika; Gessler, Arthur; Kohnle, Ulrich; Ensminger, Ingo; Rennenberg, Heinz; Wildhagen, Henning

    2018-01-01

    The coniferous forest tree Douglas-fir (Pseudotsuga menziesii) is native to the pacific North America, and is increasingly planted in temperate regions worldwide. Nitrogen (N) metabolism is of great importance for growth, resistance and resilience of trees. In the present study, foliar N metabolism of adult trees of three coastal and one interior provenance of Douglas-fir grown at two common gardens in southwestern Germany (Wiesloch, W; Schluchsee, S) were characterized in two subsequent years. Both the native North American habitats of the seed sources and the common garden sites in Germany differ in climate conditions. Total and mineral soil N as well as soil water content were higher in S compared to W. We hypothesized that i) provenances differ constitutively in N pool sizes and composition, ii) N pools are affected by environmental conditions, and iii) that effects of environmental factors on N pools differ among interior and coastal provenances. Soil water content strongly affected the concentrations of total N, soluble protein, total amino acids (TAA), arginine and glutamate. Foliar concentrations of total N, soluble protein, structural N and TAA of trees grown at W were much higher than in trees at S. Provenance effects were small but significant for total N and soluble protein content (interior provenance showed lowest concentrations), as well as arginine, asparagine and glutamate. Our data suggest that needle N status of adult Douglas-fir is independent from soil N availability and that low soil water availability induces a re-allocation of N from structural N to metabolic N pools. Small provenance effects on N pools suggest that local adaptation of Douglas-fir is not dominated by N conditions at the native habitats.

  2. Functions of Glutamine Synthetase Isoforms in the Nitrogen Metabolism of Plants

    DEFF Research Database (Denmark)

    Guan, Miao

    Nitrogen is one of the major plant nutrients limiting crop production worldwide. In many parts of the world the availability of N fertilizers is limited, whereas in other parts of the world too much N fertilizer is applied, leading to serious negative environmental consequences. The use of N...... fertilizers accordingly needs to be optimized in order to make agriculture more sustainable. One pathway to achieve such optimization is to improve plant N use efficiency (NUE) by developing new crop genotypes with improved yield per unit of N fertilizer applied. For this purpose, more and better knowledge...... about bottlenecks in plant N assimilation is needed. Based on a reverse genetics strategy embracing characterization of knockout mutants in the model plant species Arabidopsis, the results obtained in this PhD study have provided new information about the specific roles of two genes Gln1;1 and Gln1...

  3. Effect of dietary coarsely ground corn on broiler live performance, gastrointestinal tract development, apparent ileal digestibility of energy and nitrogen, and digesta particle size distribution and retention time.

    Science.gov (United States)

    Xu, Y; Stark, C R; Ferket, P R; Williams, C M; Pacheco, W J; Brake, J

    2015-01-01

    Dietary structural material has been reported to improve broiler live performance and gastrointestinal tract (GIT) function. In this 50 d cage study, the effects of coarsely ground corn (CC) inclusion on broiler live performance, GIT development, apparent ileal digestibility (AID) of energy and nitrogen (N), and digesta particle size distribution and retention time were investigated. This study included 3 CC inclusions (0, 25, and 50% fine corn [FC] replaced by CC), with 6 replicate cages of 10 birds per treatment. The feed conversion ratio (FCR) at 35 and 42 d was improved (P<0.01) as the dietary inclusion of CC increased without effect on feed intake. The 50% CC diet increased absolute and relative gizzard weight at 42 d of age as compared to diets with 0 and 25% CC (P<0.01). Dietary CC increased absolute proventriculus weight at 28 d of age (P<0.05). A numerically lower gizzard digesta pH (P<0.08) was observed at 28 d but not 42 d of age, and there was no difference in proventriculus, jejunum, or ileum digesta pH at 28 or 42 d of age. The 25 and 50% CC treatments increased the digesta retention time at 30 and 45 d of age (P<0.05 and P<0.01, respectively). The 25 and 50% CC treatments improved AID of energy by 7.1 and 8.2%, respectively, when compared with the 0% CC treatment, and they improved AID of N by 12.2 and 12.4%, respectively (P<0.01). The digesta particles in the jejunum exhibited a similar distribution, with a dgw (geometric mean diameter by mass) of 218, 204, and 181 μm when 0, 25, of 50% CC diets were consumed, respectively. In conclusion, birds fed pelleted and screened diets that contained 25 and 50% CC exhibited increased BW, improved FCR, and increased AID of energy and N, which was probably due to enhanced gizzard development and greater digesta retention time. © The Author 2015. Published by Oxford University Press on behalf of Poultry Science Association.

  4. Effects of high CO2 on growth and metabolism of Arabidopsis seedlings during growth with a constantly limited supply of nitrogen.

    Science.gov (United States)

    Takatani, Nobuyuki; Ito, Takuro; Kiba, Takatoshi; Mori, Marie; Miyamoto, Tetsuro; Maeda, Shin-Ichi; Omata, Tatsuo

    2014-02-01

    Elevated CO2 has been reported to stimulate plant growth under nitrogen-sufficient conditions, but the effects of CO2 on growth in a constantly nitrogen-limited state, which is relevant to most natural habitats of plants, remain unclear. Here, we maintained Arabidopsis seedlings under such conditions by growing a mutant with reduced nitrate uptake activity on a medium containing nitrate as the sole nitrogen source. Under nitrogen-sufficient conditions (i.e. in the presence of ammonium), growth of shoots and roots of both the wild type (WT) and the mutant was increased approximately 2-fold by elevated CO2. Growth stimulation of shoots and roots by elevated CO2 was observed in the WT growing with nitrate as the sole nitrogen source, but in the mutant grown with nitrate, the high-CO2 conditions stimulated only the growth of roots. In the mutant, elevated CO2 caused well-known symptoms of nitrogen-starved plants, including decreased shoot/root ratio, reduced nitrate content and accumulation of anthocyanin, but also had an increased Chl content in the shoot, which was contradictory to the known effect of nitrogen depletion. A high-CO2-responsive change specific to the mutant was not observed in the levels of the major metabolites, although CO2 responses were observed in the WT and the mutant. These results indicated that elevated CO2 causes nitrogen limitation in the seedlings grown with a constantly limited supply of nitrogen, but the Chl content and the root biomass of the plant increase to enhance the activities of both photosynthesis and nitrogen uptake, while maintaining normal metabolism and response to high CO2.

  5. The Effect of a Breakfast Rich in Slowly Digestible Starch on Glucose Metabolism: A Statistical Meta-Analysis of Randomized Controlled Trials.

    Science.gov (United States)

    Vinoy, Sophie; Meynier, Alexandra; Goux, Aurélie; Jourdan-Salloum, Nathalie; Normand, Sylvie; Rabasa-Lhoret, Rémi; Brack, Olivier; Nazare, Julie-Anne; Péronnet, François; Laville, Martine

    2017-03-23

    Starch digestibility may have an effect on the postprandial blood glucose profile. The aim of this meta-analysis was to analyze the relationship between Slowly Digestible Starch (SDS) levels and plasma glucose appearance and disappearance rates, as well as other parameters of glucose metabolism, after healthy subjects consumed cereal products that differed in SDS content. Three randomized controlled clinical trials that included a total of 79 subjects were identified. Using binary classification for the variables (high versus low levels, more than 12 g of SDS per portion, and less than 1 g of SDS per portion, respectively), we found that there was a 15-fold higher chance of having a low rate of appearance of exogenous glucose (RaE) after consumption of a high-SDS product. A high SDS content was also associated with a 12-fold and 4-fold higher chance of having a low rate of disappearance of exogenous glucose (RdE) and rate of disappearance of total plasma glucose (RdT), respectively. The RaE kinetics were further analyzed by modeling the contribution of SDS content to the different phases of the RaE response. We show that the higher the SDS content per portion of cereal product, the higher its contribution to the incremental area under the curve (iAUC) of the RaE response after 165 min. Using the association rule technique, we found that glycemic iAUC and insulinemic iAUC values vary in the same direction. In conclusion, this meta-analysis confirms the effect of the SDS level in cereal products on the metabolic response, and shows for the first time that the degree to which SDS affects the RaE response differs depending on the SDS content of the food product, as well as the phase of the postprandial period.

  6. Lisina digestível e zinco quelado para frangos de corte machos: desempenho e retenção de nitrogênio na fase pré-inicial Digestible lysine and zinc chelate to male broiler: Performance in the pre-initial phase and nitrogen retention

    Directory of Open Access Journals (Sweden)

    Lilian Bernadete Namazu

    2008-09-01

    Full Text Available Em dois ensaios experimentais, avaliaram-se níveis de lisina digestível (0,90; 1,00; 1,10; 1,20 e 1,40% combinados a zinco quelado (43 e 253 ppm para frangos de corte machos. Os períodos considerados foram: 1 a 11 dias de idade (desempenho e 1 a 7 dias de idade (balanço de nitrogênio. O delineamento experimental utilizado foi de blocos ao acaso, em esquema fatorial 5 × 2. No ensaio de desempenho, utilizaram-se 7 repetições e 15 aves por unidade experimental e, no ensaio de digestibilidade, 6 repetições e 6 aves por unidade experimental. As dietas continham 2.960 de EM/kg e 21% de proteína bruta. Na fase de 1 a 11 dias de idade, não houve efeito de interação lisina digestível × zinco quelado no desempenho, mas verificou-se efeito quadrático dos níveis de lisina digestível sobre o peso final, o ganho de peso e o ganho de peso relativo e efeito linear crescente no consumo de ração. A conversão alimentar não diferiu com as variações dos níveis de lisina digestível e zinco na dieta. Nas condições de avaliação do desempenho, o nível ótimo de lisina digestível para frangos de corte machos mantidos em piso de concreto é de 1,19%. Na fase de 1 a 7 dias de idade, não houve influência da relação entre níveis de lisina digestível e zinco quelado no balanço de nitrogênio. A retenção de nitrogênio aumentou de forma linear crescente com o aumento da concentração de lisina digestível na dieta, o que está de acordo com o aumento linear do ganho de peso e da eficiência alimentar. A exigência de lisina digestível para frangos de corte machos de 1 a 7 dias de idade é igual ou superior a 1,40%.Two experiments were carried out to evaluate different levels of digestible lysine (0.90; 1.00; 1.10; 1.20; e 1.40% combined with zinc chelate (43 and 253 ppm to male broiler. The considered periods were: initial phase - performance (1 to 11 days old and nitrogen retention (1 to 7 days old. A randomized block experimental

  7. Seed and Foliar Application of Amino Acids Improve Variables of Nitrogen Metabolism and Productivity in Soybean Crop.

    Science.gov (United States)

    Teixeira, Walquíria F; Fagan, Evandro B; Soares, Luis H; Soares, Jérssica N; Reichardt, Klaus; Neto, Durval D

    2018-01-01

    The application of amino acids in crops has been a common practice in recent years, although most of the time they are associated with products based on algae extracts or on fermented animal or vegetable wastes. However, little is known about the isolated effect of amino acids on the development of crops. Therefore, the objective of this research was to evaluate the effect of the application of isolated amino acids on the in some steps of the soybean nitrogen metabolism and on productivity. Experiments were carried out in a greenhouse and in the field with the application of the amino acids glutamate (Glu), phenylalanine (Phe), cysteine (Cys) and glycine (Gly) and as a set (Glu+Phe+Cys+Gly), as seed treatment (ST), as foliar application (FA) and both (ST+FA), at the V 4 growth stage. Evaluations consisted of nitrate reductase and urease activities, nitrate, ureide, total amino acids and total nitrogen content in leaves, and productivity. The application of Glu to leaves, Cys as ST and a mixture of Glu+Cys+Phe+Gly as ST+FA in the greenhouse experiment increased the total amino acids content. In the field experiment all treatments increased the amino acid content in leaves. At the V 6 stage in the field experiment, all modes of Gly application, Glu as ST and FA, Cys and Phe as ST+FA and Glu+Cys+Phe+Gly as FA increased the nitrate content in leaves. In the greenhouse, application of Cys and Phe as ST increased the production of soybean plants by at least 21%. The isolated application of Cys, Phe, Gly, Glu and the set of these amino acids as ST increased the productivity of soybean plants in the field experiment by at least 22%.

  8. Seed and Foliar Application of Amino Acids Improve Variables of Nitrogen Metabolism and Productivity in Soybean Crop

    Science.gov (United States)

    Teixeira, Walquíria F.; Fagan, Evandro B.; Soares, Luis H.; Soares, Jérssica N.; Reichardt, Klaus; Neto, Durval D.

    2018-01-01

    The application of amino acids in crops has been a common practice in recent years, although most of the time they are associated with products based on algae extracts or on fermented animal or vegetable wastes. However, little is known about the isolated effect of amino acids on the development of crops. Therefore, the objective of this research was to evaluate the effect of the application of isolated amino acids on the in some steps of the soybean nitrogen metabolism and on productivity. Experiments were carried out in a greenhouse and in the field with the application of the amino acids glutamate (Glu), phenylalanine (Phe), cysteine (Cys) and glycine (Gly) and as a set (Glu+Phe+Cys+Gly), as seed treatment (ST), as foliar application (FA) and both (ST+FA), at the V4 growth stage. Evaluations consisted of nitrate reductase and urease activities, nitrate, ureide, total amino acids and total nitrogen content in leaves, and productivity. The application of Glu to leaves, Cys as ST and a mixture of Glu+Cys+Phe+Gly as ST+FA in the greenhouse experiment increased the total amino acids content. In the field experiment all treatments increased the amino acid content in leaves. At the V6 stage in the field experiment, all modes of Gly application, Glu as ST and FA, Cys and Phe as ST+FA and Glu+Cys+Phe+Gly as FA increased the nitrate content in leaves. In the greenhouse, application of Cys and Phe as ST increased the production of soybean plants by at least 21%. The isolated application of Cys, Phe, Gly, Glu and the set of these amino acids as ST increased the productivity of soybean plants in the field experiment by at least 22%. PMID:29643860

  9. Alterations in sulfur and nitrogen metabolism in rats with portacaval shunts

    International Nuclear Information System (INIS)

    Benjamin, L.E.

    1985-01-01

    The effect of portacaval shunt (PCS) on methionine and cysteine metabolism was investigated. PCS rats excreted more urinary [ 35 S]sulfate and less [ 35 S]taurine than controls after injection of [ 35 S]methionine of [ 35 S]cysteine. Total urinary taurine excretion was unchanged. Under basal conditions PCS rats excreted more taurine than controls. Relative rates of transsulfuration in PCS and control rats were studied, and no difference in flux of 35 S from methionine to cysteine was found. Total hepatic activities of three transsulfuration pathway enzymes were also unchanged after PCS. In contrast, hepatic activities of three cysteine-oxidizing enzymes were depressed after PCS, suggesting that changes in hepatic metabolism after PCS are selective. PCS rats fed a high (60%) casein diet ate less and took longer to recover their preoperative body weight than controls. All PCS rats had higher plasma ammonia and urinary orotic acid levels than controls. Increasing dietary protein elevated plasma ammonia and urinary orotic acid to a greater extent in PCS rats. After injection of [ 35 S]methionine or [ 35 S]cysteine, urinary 35 S and [ 35 S]sulfate excretion increased and [ 35 S]taurine an total taurine excretion decreased in all rats fed 60% casein, but the effect was greater in PCS rats. Changes in cysteine sulfinate decarboxylase activity in rats fed a high protein diet was examined. Activity decreased 95% in rats fed diets containing between 18 and 75% casein. The effect was observed after feeding a 60% casein diet for 2 days and was reversed when rats were refed an 18% casein diet

  10. Digestibilidade total e balanço de nitrogênio em cabritos recebendo rações contendo levedura seca = Total digestibility and nitrogen balance in kid goats receiving diets containing dry yeast

    Directory of Open Access Journals (Sweden)

    Claudete Regina Alcalde

    2011-07-01

    Full Text Available O experimento foi conduzido com o objetivo de avaliar a ingestão,digestibilidade da matéria seca e dos nutrientes, o balanço de nitrogênio e estimar os nutrientes digestíveis totais de rações com a inclusão da levedura seca (0, 25, 50, 75 e 100% da MS em substituição ao farelo de soja nas rações para cabritos. Foram utilizados cinco cabritos SRD alojados em gaiolas metabólicas distribuídos em delineamento quadrado latino 5 x 5. As ingestões de matéria seca e de carboidratos totais não foram alteradas com ainclusão de levedura, no entanto, para a ingestão de matéria orgânica, proteína bruta, extrato etéreo e fibra em detergente neutro foi observado efeito quadrático. A digestibilidade do extrato etéreo apresentou efeito linear decrescente, porém, para digestibilidade da matéria seca, matéria orgânica, proteína bruta, carboidratos totais, fibra em detergente neutro e nutrientes digestíveis totais houve efeito quadrático. O balanço de nitrogênio não foi alterado em função da substituição do farelo de soja. A levedura seca pode ser incluída nas rações de cabritos como fonte proteica sem alterar a ingestão de matéria seca e o balanço de nitrogênio, porém, a inclusão acima de 5,9% de levedura seca nas rações reduz a digestibilidade da matéria seca.The assay was carried out to evaluate feed intake, dry matter andnutrient digestibility, nitrogen balance, and to estimate total digestible nutrients of diets with inclusion of dry yeast (0, 25, 50, 75, 100% of DM replacing soybean meal in diets for kid goats. Five goats were allotted in a 5 x 5 Latin square design and housed in digestibility cages. Dry matter intake and total carbohydrates were unchanged with inclusion of dry yeast; however, for organic matter, crude protein, ether extract and neutral detergent fiber, intake showed a quadratic effect. The digestibility of ether extract showed decreasing linear effect; however, for dry matter, organic matter

  11. Genome analysis coupled with physiological studies reveals a diverse nitrogen metabolism in Methylocystis sp. strain SC2.

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    Bomba Dam

    Full Text Available BACKGROUND: Methylocystis sp. strain SC2 can adapt to a wide range of methane concentrations. This is due to the presence of two isozymes of particulate methane monooxygenase exhibiting different methane oxidation kinetics. To gain insight into the underlying genetic information, its genome was sequenced and found to comprise a 3.77 Mb chromosome and two large plasmids. PRINCIPAL FINDINGS: We report important features of the strain SC2 genome. Its sequence is compared with those of seven other methanotroph genomes, comprising members of the Alphaproteobacteria, Gammaproteobacteria, and Verrucomicrobia. While the pan-genome of all eight methanotroph genomes totals 19,358 CDS, only 154 CDS are shared. The number of core genes increased with phylogenetic relatedness: 328 CDS for proteobacterial methanotrophs and 1,853 CDS for the three alphaproteobacterial Methylocystaceae members, Methylocystis sp. strain SC2 and strain Rockwell, and Methylosinus trichosporium OB3b. The comparative study was coupled with physiological experiments to verify that strain SC2 has diverse nitrogen metabolism capabilities. In correspondence to a full complement of 34 genes involved in N2 fixation, strain SC2 was found to grow with atmospheric N2 as the sole nitrogen source, preferably at low oxygen concentrations. Denitrification-mediated accumulation of 0.7 nmol (30N2/hr/mg dry weight of cells under anoxic conditions was detected by tracer analysis. N2 production is related to the activities of plasmid-borne nitric oxide and nitrous oxide reductases. CONCLUSIONS/PERSPECTIVES: Presence of a complete denitrification pathway in strain SC2, including the plasmid-encoded nosRZDFYX operon, is unique among known methanotrophs. However, the exact ecophysiological role of this pathway still needs to be elucidated. Detoxification of toxic nitrogen compounds and energy conservation under oxygen-limiting conditions are among the possible roles. Relevant features that may stimulate

  12. Constraint-Based Modeling Highlights Cell Energy, Redox Status and α-Ketoglutarate Availability as Metabolic Drivers for Anthocyanin Accumulation in Grape Cells Under Nitrogen Limitation

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    Eric Soubeyrand

    2018-05-01

    Full Text Available Anthocyanin biosynthesis is regulated by environmental factors (such as light, temperature, and water availability and nutrient status (such as carbon, nitrogen, and phosphate nutrition. Previous reports show that low nitrogen availability strongly enhances anthocyanin accumulation in non carbon-limited plant organs or cell suspensions. It has been hypothesized that high carbon-to-nitrogen ratio would lead to an energy excess in plant cells, and that an increase in flavonoid pathway metabolic fluxes would act as an “energy escape valve,” helping plant cells to cope with energy and carbon excess. However, this hypothesis has never been tested directly. To this end, we used the grapevine Vitis vinifera L. cultivar Gamay Teinturier (syn. Gamay Freaux or Freaux Tintorier, VIVC #4382 cell suspension line as a model system to study the regulation of anthocyanin accumulation in response to nitrogen supply. The cells were sub-cultured in the presence of either control (25 mM or low (5 mM nitrate concentration. Targeted metabolomics and enzyme activity determinations were used to parametrize a constraint-based model describing both the central carbon and nitrogen metabolisms and the flavonoid (phenylpropanoid pathway connected by the energy (ATP and reducing power equivalents (NADPH and NADH cofactors. The flux analysis (2 flux maps generated, for control and low nitrogen in culture medium clearly showed that in low nitrogen-fed cells all the metabolic fluxes of central metabolism were decreased, whereas fluxes that consume energy and reducing power, were either increased (upper part of glycolysis, shikimate, and flavonoid pathway or maintained (pentose phosphate pathway. Also, fluxes of flavanone 3β-hydroxylase, flavonol synthase, and anthocyanidin synthase were strongly increased, advocating for a regulation of the flavonoid pathway by alpha-ketoglutarate levels. These results strongly support the hypothesis of anthocyanin biosynthesis acting as

  13. Excretory nitrogen metabolism in the juvenile axolotl Ambystoma mexicanum: differences in aquatic and terrestrial environments.

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    Loong, Ai M; Chew, Shit F; Ip, Yuen K

    2002-01-01

    The fully grown but nonmetamorphosed (juvenile) axolotl Ambystoma mexicanum was ureogenic and primarily ureotelic in water. A complete ornithine-urea cycle (OUC) was present in the liver. Aerial exposure impeded urea (but not ammonia) excretion, leading to a decrease in the percentage of nitrogen excreted as urea in the first 24 h. However, urea and not ammonia accumulated in the muscle, liver, and plasma during aerial exposure. By 48 h, the rate of urea excretion recovered fully, probably due to the greater urea concentration gradient in the kidney. It is generally accepted that an increase in carbamoyl phosphate synthetase activity is especially critical in the developmental transition from ammonotelism to ureotelism in the amphibian. Results from this study indicate that such a transition in A. mexicanum would have occurred before migration to land. Aerial exposure for 72 h exhibited no significant effect on carbamoyl phosphate synthetase-I activity or that of other OUC enzymes (with the exception of ornithine transcarbamoylase) from the liver of the juvenile A. mexicanum. This supports our hypothesis that the capacities of OUC enzymes present in the liver of the aquatic juvenile axolotl were adequate to prepare it for its invasion of the terrestrial environment. The high OUC capacity was further supported by the capability of the juvenile A. mexicanum to survive in 10 mM NH(4)Cl without accumulating amino acids in its body. The majority of the accumulating endogenous and exogenous ammonia was detoxified to urea, which led to a greater than twofold increase in urea levels in the muscle, liver, and plasma and a significant increase in urea excretion by hour 96. Hence, it can be concluded that the juvenile axolotl acquired ureotelism while submerged in water, and its hepatic capacity of urea synthesis was more than adequate to handle the toxicity of endogenous ammonia during migration to land.

  14. Interaction of Sulfate Assimilation with Carbon and Nitrogen Metabolism in Lemna minor1

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    Kopriva, Stanislav; Suter, Marianne; von Ballmoos, Peter; Hesse, Holger; Krähenbühl, Urs; Rennenberg, Heinz; Brunold, Christian

    2002-01-01

    Cysteine synthesis from sulfide and O-acetyl-l-serine (OAS) is a reaction interconnecting sulfate, nitrogen, and carbon assimilation. Using Lemna minor, we analyzed the effects of omission of CO2 from the atmosphere and simultaneous application of alternative carbon sources on adenosine 5′-phosphosulfate reductase (APR) and nitrate reductase (NR), the key enzymes of sulfate and nitrate assimilation, respectively. Incubation in air without CO2 led to severe decrease in APR and NR activities and mRNA levels, but ribulose-1,5-bisphosphate carboxylase/oxygenase was not considerably affected. Simultaneous addition of sucrose (Suc) prevented the reduction in enzyme activities, but not in mRNA levels. OAS, a known regulator of sulfate assimilation, could also attenuate the effect of missing CO2 on APR, but did not affect NR. When the plants were subjected to normal air after a 24-h pretreatment in air without CO2, APR and NR activities and mRNA levels recovered within the next 24 h. The addition of Suc and glucose in air without CO2 also recovered both enzyme activities, with OAS again influenced only APR. 35SO42− feeding showed that treatment in air without CO2 severely inhibited sulfate uptake and the flux through sulfate assimilation. After a resupply of normal air or the addition of Suc, incorporation of 35S into proteins and glutathione greatly increased. OAS treatment resulted in high labeling of cysteine; the incorporation of 35S in proteins and glutathione was much less increased compared with treatment with normal air or Suc. These results corroborate the tight interconnection of sulfate, nitrate, and carbon assimilation. PMID:12428005

  15. Carbohydrate metabolism is essential for the colonization of Streptococcus thermophilus in the digestive tract of gnotobiotic rats.

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    Muriel Thomas

    Full Text Available Streptococcus thermophilus is the archetype of lactose-adapted bacterium and so far, its sugar metabolism has been mainly investigated in vitro. The objective of this work was to study the impact of lactose and lactose permease on S. thermophilus physiology in the gastrointestinal tract (GIT of gnotobiotic rats. We used rats mono-associated with LMD-9 strain and receiving 4.5% lactose. This model allowed the analysis of colonization curves of LMD-9, its metabolic profile, its production of lactate and its interaction with the colon epithelium. Lactose induced a rapid and high level of S. thermophilus in the GIT, where its activity led to 49 mM of intra-luminal L-lactate that was related to the induction of mono-carboxylic transporter mRNAs (SLC16A1 and SLC5A8 and p27(Kip1 cell cycle arrest protein in epithelial cells. In the presence of a continuous lactose supply, S. thermophilus recruited proteins involved in glycolysis and induced the metabolism of alternative sugars as sucrose, galactose, and glycogen. Moreover, inactivation of the lactose transporter, LacS, delayed S. thermophilus colonization. Our results show i/that lactose constitutes a limiting factor for colonization of S. thermophilus, ii/that activation of enzymes involved in carbohydrate metabolism constitutes the metabolic signature of S. thermophilus in the GIT, iii/that the production of lactate settles the dialogue with colon epithelium. We propose a metabolic model of management of carbohydrate resources by S. thermophilus in the GIT. Our results are in accord with the rationale that nutritional allegation via consumption of yogurt alleviates the symptoms of lactose intolerance.

  16. Batch and semi-continuous anaerobic co-digestion of goose manure with alkali solubilized wheat straw: A case of carbon to nitrogen ratio and organic loading rate regression optimization.

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    Hassan, Muhammad; Ding, Weimin; Umar, Muhammad; Rasool, Ghulam

    2017-04-01

    The present study focused on carbon to nitrogen ratio (C/N) and organic loading rate (OLR) optimization of goose manure (GM) and wheat straw (WS). Dealing the anaerobic digestion of poultry manure on industrial scale; the question of optimum C/N (mixing ratio) and OLR (daily feeding concentration) have significant importance still lack in literature. Therefore, Batch and CSTR co-digestion experiments of the GM and WS were carried out at mesophilic condition. The alkali (NaOH) solubilization pretreatment for the WS had greatly enhanced its anaerobic digestibility. The highest methane production was evaluated between the C/N of 20-30 during Batch experimentation while for CSTRs; the second applied OLR of (3g.VS/L.d) was proved as the optimum with maximum methane production capability of 254.65ml/g.VS for reactor B at C/N of 25. The C/N and OLR regression optimization models were developed for their commercial scale usefulness. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Studies of the nitrogen metabolism in the large intestine of ruminants. 5

    International Nuclear Information System (INIS)

    Bergner, H.; Goetz, K.P.; Simon, O.

    1989-01-01

    Six heifers of a live weight of 215, 227 and 238 kg (experiment 1) and 220, 227 and 233 kg resp. (experiment 2) were supplied with ileocaecal re-entrance cannulae, jugular venal catheters and bladder catheters. The ration consisted of 4 kg maize silage and 4 kg wheat straw pellets per animal and day. Up to 3.5 kg of the straw pellets consisting of 73% wheat straw, 10% barley, 12% molasses, NPN salts and a mineral mixture were consumed per animal and day. In a preliminary period 50% of the digesta flow was collected over 12 h/d on 5 consecutive days and stored in a deep-freeze. During the main trial the re-entrance cannula was disrupted and the flowing digesta was quantitatively collected at the end of the ileum; previously collected digesta was supplemented with 15 N-urea and every hour over 24 h infused into the caecal part of the re-entrance cannula. Between the 24th and 30th hours the digesta was infused without 15 N-urea supplement. In trial 2 the digesta was also supplemented with partly hydrolysed straw meal between the 1st and 30th hours. The 15 N labelling decrease of the plasma urea N shows that the half life is 7.9 h in trial 1 and 7.0 h in trial 2. The NH 3 nitrogen in faeces was distinctly higher labelled in trial 2 after the supplement of straw meal than in trial 1. The total N in faeces was also twice as highly labelled as in trial 1. Atom-% 15 N' in urine was significantly higher in trial 2 than in trial 1 between the 6th and 16th hours after the beginning of 15 N-urea supplementation. In the decrease curve of atom-% 15 N' (after the 26th hour of trial) the values in trial 1 were generally higher than in trial 2. The higher bacterial protein synthesis in the large intestine in trial 2 had the effect that 13.6% of the supplemented 15 N' were excreted in faeces by the 30th hour of trial, in contrast to this only 4.7% in group 1. (author)

  18. Efficacy of β-mannanase supplementation to corn-soya bean meal-based diets on growth performance, nutrient digestibility, blood urea nitrogen, faecal coliform and lactic acid bacteria and faecal noxious gas emission in growing pigs.

    Science.gov (United States)

    Upadhaya, Santi Devi; Park, Jae Won; Lee, Jae Hwan; Kim, In Ho

    2016-01-01

    A study was conducted to determine the efficacy of β-mannanase supplementation to a diet based on corn and soya bean meal (SBM) on growth performance, nutrient digestibility, blood urea nitrogen (BUN), faecal coliforms and lactic acid bacteria, and noxious gas emission in growing pigs. A total of 140 pigs [(Landrace × Yorkshire) × Duroc; average body weight 25 ± 3 kg] were randomly allotted to a 2 × 2 factorial arrangement with dietary treatments consisting of hulled or dehulled SBM without or with supplementation of 400 U β-mannanase/kg. During the 6 weeks of experimental feeding, β-mannanase supplementation had no effect on body weight gain, feed intake and gain:feed (G:F) ratio. Compared with dehulled SBM, feeding hulled SBM caused an increased feed intake of pigs in the entire trial (p = 0.05). The G:F ratio was improved in pigs receiving dehulled SBM (p < 0.05). Dietary treatments did not influence the total tract digestibility of dry matter, nitrogen and gross energy. Enzyme supplementation reduced (p < 0.05) the population of faecal coliforms and tended to reduce the NH3 concentration after 24 h of fermentation in a closed box containing faecal slurry. Feeding hulled SBM tended to reduce NH3 emission on days 3 and 5 of fermentation. In conclusion, mannanase supplementation had no influence on growth performance and nutrient digestibility but showed a positive effect on reducing coliform population and tended to reduce NH3 emission. Dehulled SBM increased G:F ratio and hulled SBM tended to reduce NH3 emission.

  19. Utilization of tritiated water dilution technique in determination of nitrogen partitioning in cashmere goats

    International Nuclear Information System (INIS)

    Wang Linfeng; Yang Gaiqing; Liu Ping; Zhang Shijun

    2010-01-01

    In order to investigate nitrogen partitioning in local cashmere goats, six Inner Mogolia White Cashmere goats between 2 to 2.5 years old were used to determine the nitrogen partitioning in cashmere goats. The total retained nitrogen (TN) in body, distribution of body nitrgen and hair nitrogen were measured by general digestive and metabolism method combined with tritiated water dilution technique. Results showed that the combined methods were ideal for determining body nitrgen (BN) and hair nitrogen (fur nitrogen, FN) of Cashmere goats. There were obvious significance between BN and FN in different seasons. In telogen, BN and FN partitioning was 75.7% ± 0.62% and 24.3% ± 0.62%, respectively. Whereas, it changed to 66.6% ± 2.2% and 33.4% ± 2.2% in anagen. BN partitioning decreased when the season changed from telogen to anagen, while FN partitioning increased, which indicated that more nitrogen substance was partitioned to body growth in telogen, and more nitrogen substance was distribute to cashmere growth in anagen. These transformation were related to the changing of photoperiod and some hormones, such as melatonin (MT), prolactin (PRL) and IGF-I. It could be concluded that tritiated water dilution technique can be used to detect body protein content as well as BN, combining general digestive and metabolism experiment, FN partitoning can be determined. BN and FN partitoning varied with the season in cashmere goats because of hormones changing. (authors)

  20. Effects of phosphorus application on photosynthetic carbon and nitrogen metabolism, water use efficiency and growth of dwarf bamboo (Fargesia rufa) subjected to water deficit.

    Science.gov (United States)

    Liu, Chenggang; Wang, Yanjie; Pan, Kaiwen; Jin, Yanqiang; Li, Wei; Zhang, Lin

    2015-11-01

    Dwarf bamboo (Fargesia rufa Yi), one of the staple foods for the endangered giant pandas, is highly susceptible to water deficit due to its shallow roots. In the face of climate change, maintenance and improvement in its productivity is very necessary for the management of the giant pandas' habitats. However, the regulatory mechanisms underlying plant responses to water deficit are poorly known. To investigate the effects of P application on photosynthetic C and N metabolism, water use efficiency (WUE) and growth of dwarf bamboo under water deficit, a completely randomized design with two factors of two watering (well-watered and water-stressed) and two P regimes (with and without P fertilization) was arranged. P application hardly changed growth, net CO2 assimilation rate (P(n)) and WUE in well-watered plants but significantly increased relative growth rate (RGR) and P(n) in water-stressed plants. The effect of P application on RGR under water stress was mostly associated with physiological adjustments rather than with differences in biomass allocation. P application maintained the balance of C metabolism in well-watered plants, but altered the proportion of nitrogenous compounds in N metabolism. By contrast, P application remarkably increased sucrose-metabolizing enzymes activities with an obvious decrease in sucrose content in water-stressed plants, suggesting an accelerated sucrose metabolism. Activation of nitrogen-metabolizing enzymes in water-stressed plants was attenuated after P application, thus slowing nitrate reduction and ammonium assimilation. P application hardly enlarged the phenotypic plasticity of dwarf bamboo in response to water in the short term. Generally, these examined traits of dwarf bamboo displayed weak or negligible responses to water-P interaction. In conclusion, P application could accelerate P(n) and sucrose metabolism and slow N metabolism in water-stressed dwarf bamboo, and as a result improved RGR and alleviated damage from soil

  1. Microplastics have a more profound impact than elevated temperatures on the predatory performance, digestion and energy metabolism of an Amazonian cichlid.

    Science.gov (United States)

    Wen, Bin; Zhang, Nan; Jin, Shi-Rong; Chen, Zai-Zhong; Gao, Jian-Zhong; Liu, Ying; Liu, Han-Peng; Xu, Zhe

    2018-02-01

    Knowledge on the impacts of microplastics (MPs) pollution on freshwater environments and biota remains limited. Meanwhile, freshwater ecosystems have been threatened by elevated temperatures caused by climate change. To date, no information exists on how MPs-especially under elevated temperature conditions-affect predatory performance, digestive processes and metabolic pathways in freshwater organisms. Here, we examined MPs, elevated temperature and their combined effects on juveniles (0+ group) of an Amazonian cichlid, the discus fish (Symphysodon aequifasciatus). For 30 days, fish were exposed to ambient or elevated temperatures (i.e., 28 or 31 °C) in the absence or presence of MPs (i.e., 0 or 200 μg/L). The following metrics were quantified: MPs accumulation; predatory performance; and biomarkers involved in neurotransmission, digestion and energy production. The results showed that survival rate and body length were not affected by MPs, elevated temperatures or their combination. Elevated temperatures resulted in an increase in MP concentrations in fish bodies. Exposure to MPs decreased the post-exposure predatory performance (PEPP) at ambient temperatures but not at elevated temperatures. Elevated temperatures, however, had no effect on the PEPP but antagonistically interacted with MPs, leading to similar predatory performances under present and future conditions. Acetylcholinesterase (AChE) activity was only affected by MPs and decreased in the presence of MPs, indicating adverse effects in nervous and neuromuscular function and, thus, potentially in predatory performance. Trypsin activity was only influenced by MPs and decreased during exposure to MPs. Elevated temperatures or MPs alone increased the amylase activity but interacted antagonistically. Lipase activity was not influenced by either of the two stressors. In contrast, alkaline phosphatase (ALP) activity was affected by MPs or elevated temperatures alone and decreased with both stressors

  2. Nitrogen-Fixing Nodules Are an Important Source of Reduced Sulfur, Which Triggers Global Changes in Sulfur Metabolism in Lotus japonicus.

    Science.gov (United States)

    Kalloniati, Chrysanthi; Krompas, Panagiotis; Karalias, Georgios; Udvardi, Michael K; Rennenberg, Heinz; Herschbach, Cornelia; Flemetakis, Emmanouil

    2015-09-01

    We combined transcriptomic and biochemical approaches to study rhizobial and plant sulfur (S) metabolism in nitrogen (N) fixing nodules (Fix(+)) of Lotus japonicus, as well as the link of S-metabolism to symbiotic nitrogen fixation and the effect of nodules on whole-plant S-partitioning and metabolism. Our data reveal that N-fixing nodules are thiol-rich organs. Their high adenosine 5'-phosphosulfate reductase activity and strong (35)S-flux into cysteine and its metabolites, in combination with the transcriptional upregulation of several rhizobial and plant genes involved in S-assimilation, highlight the function of nodules as an important site of S-assimilation. The higher thiol content observed in nonsymbiotic organs of N-fixing plants in comparison to uninoculated plants could not be attributed to local biosynthesis, indicating that nodules are an important source of reduced S for the plant, which triggers whole-plant reprogramming of S-metabolism. Enhanced thiol biosynthesis in nodules and their impact on the whole-plant S-economy are dampened in plants nodulated by Fix(-) mutant rhizobia, which in most respects metabolically resemble uninoculated plants, indicating a strong interdependency between N-fixation and S-assimilation. © 2015 American Society of Plant Biologists. All rights reserved.

  3. Use of dried cassava root to replace corn in supplementation of Holstein cows grazing and consuming spontaneously, apparent digestibility and energy metabolism

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    Ádler Carvalho da Silva

    2015-07-01

    Full Text Available The development of this experiment intended to evaluate the effect of replacing ground corn for dried and ground cassava roots with the levels of 0%, 25%, 50%, 75% and 100% in the experimental supplements for lactating cows kept on tropical irrigated and fertilized pastures. Ten Holstein cows were divided into two 5x5 Latin squares, with an initial lactation average of 150 days, 22 kg/day of average milk production of lactation and approximate initial average body eight of 603 kg. The animals were kept in pasture constituted by elephant grass (Pennisetum purpureum, SCHUM cv Pioneer, associated with Tifton 85 grass (Cynodon nlemfuensis, irrigated and fertilized with 600 kg of nitrogen per hectare/year. No significant effects on the substitution of ground corn for dried and ground cassava roots in the concentrate (P>0.05 over the spontaneous consumption of the total diet, with estimated average of 20.61 kg/DM/animal/day, apparent digestibility of DM with estimated average of 59.60% and energy balance with estimated average of +6.36 Mcal day-1. The results of this study demonstrate that the cassava root can be used as an energy source of high nutritional value for supplementation of lactating cows grazing on tropical pastures, similar to corn results.

  4. Slowly and rapidly digested fat emulsions are equally satiating but their triglycerides are differentially absorbed and metabolized in humans.

    Science.gov (United States)

    Keogh, Jennifer B; Wooster, Tim J; Golding, Matthew; Day, Li; Otto, Bärbel; Clifton, Peter M

    2011-05-01

    Little is known about the effect of dietary fat emulsion microstructure on plasma TG concentrations, satiety hormones, and food intake. The aim of this study was to structure dietary fat to slow digestion and flatten postprandial plasma TG concentrations but not increase food intake. Emulsions were stabilized by egg lecithin (control), sodium sterol lactylate, or sodium caseinate/monoglyceride (CasMag) with either liquid oil or a liquid oil/solid fat mixture. In a randomized, double-blind, crossover design, 4 emulsions containing 30 g of fat in a 350-mL preload were consumed by 10 men and 10 women (BMI = 25.1 ± 2.8 kg/m(2); age = 58.8 ± 4.8 y). Pre- and postprandial plasma TG, cholecystokinin (CCK), glucagon-like peptide-1 (GLP-1), and peptide YY (PYY) concentrations and food intake were measured. In a second experiment in a subset of the participants (n = 8, 4 men and 4 women), (13)C-labeled mixed TG was incorporated into 2 different emulsions and breath (13)C was measured over 6 h. In the first experiment, the postprandial rise in plasma TG concentrations following the CasMag-stabilized emulsion containing 30% solid fat was lower than all other emulsions at 90 and 120 min (P structured to decrease its effect on plasma TG concentrations without increasing food intake.

  5. Metabolism

    Science.gov (United States)

    ... Are More Common in People With Type 1 Diabetes Metabolic Syndrome Your Child's Weight Healthy Eating Endocrine System Blood Test: Basic Metabolic Panel (BMP) Activity: Endocrine System Growth Disorders Diabetes Center Thyroid Disorders Your Endocrine System Movie: Endocrine ...

  6. New features on the environmental regulation of metabolism revealed by modeling the cellular proteomic adaptations induced by light, carbon and inorganic nitrogen in Chlamydomonas reinhardtii

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    Stéphanie Gérin

    2016-08-01

    Full Text Available Microalgae are currently emerging to be very promising organisms for the production of biofuels and high-added value compounds. Understanding the influence of environmental alterations on their metabolism is a crucial issue. Light, carbon and nitrogen availability have been reported to induce important metabolic adaptations. So far, the influence of these variables has essentially been studied while varying only one or two environmental factors at the same time. The goal of the present work was to model the cellular proteomic adaptations of the green microalga Chlamydomonas reinhardtii upon the simultaneous changes of light intensity, carbon concentrations (CO2 and acetate and inorganic nitrogen concentrations (nitrate and ammonium in the culture medium. Statistical design of experiments (DOE enabled to define 32 culture conditions to be tested experimentally. Relative protein abundance was quantified by two dimensional differential in-gel electrophoresis (2D-DIGE. Additional assays for respiration, photosynthesis, and lipid and pigment concentrations were also carried out. A hierarchical clustering survey enabled to partition biological variables (proteins + assays into eight co-regulated clusters. In most cases, the biological variables partitioned in the same cluster had already been reported to participate to common biological functions (acetate assimilation, bioenergetic processes, light harvesting, Calvin cycle and protein metabolism. The environmental regulation within each cluster was further characterized by a series of multivariate methods including principal component analysis and multiple linear regressions. This metadata analysis enabled to highlight the existence of a clear regulatory pattern for every cluster and to mathematically simulate the effects of light, carbon and nitrogen. The influence of these environmental variables on cellular metabolism is described in details and thoroughly discussed. This work provides an overview

  7. Light-dark (12:12) cycle of carbon and nitrogen metabolism in Crocosphaera watsonii WH8501: relation to the cell cycle.

    Science.gov (United States)

    Dron, Anthony; Rabouille, Sophie; Claquin, Pascal; Le Roy, Bertrand; Talec, Amélie; Sciandra, Antoine

    2012-04-01

    This study provides with original data sets on the physiology of the unicellular diazotrophic cyanobacterium Crocosphaera watsonii WH8501, maintained in continuous culture in conditions of obligate diazotrophy. Cultures were exposed to a 12:12 light-dark regime, representative of what they experience in nature and where growth is expected to be balanced. Nitrogen and carbon metabolism were monitored at high frequency and their dynamics was compared with the cell cycle. Results reveal a daily cycle in the physiological and biochemical parameters, tightly constrained by the timely decoupled processes of N(2) fixation and carbon acquisition. The cell division rate increased concomitantly to carbon accumulation and peaked 6 h into the light. The carbon content reached a maximum at the end of the light phase. N(2) fixation occurred mostly during the dark period and peaked between 9 and 10 h into the night, while DNA synthesis, reflected by DNA fluorescence, increased until the end of the night. Consequently, cells in G1- and S-phases present a marked decrease in their C:N ratio. Nitrogen acquisition through N(2) fixation exceeded 1.3- to 3-fold the nitrogen requirements for growth, suggesting that important amounts of nitrogen are excreted even under conditions supposed to favour balanced, carbon and nitrogen acquisitions. © 2011 Society for Applied Microbiology and Blackwell Publishing Ltd.

  8. Drug-DNA adducts as biomarkers for metabolic activation of the nitro-aromatic nitrogen mustard prodrug PR-104A.

    Science.gov (United States)

    Stornetta, Alessia; Deng, Kai-Cheng Kieren; Danielli, Sara; Liyanage, H D Sarath; Sturla, Shana J; Wilson, William R; Gu, Yongchuan

    2018-04-07

    PR-104A is a clinical-stage nitrogen mustard prodrug that is activated for DNA alkylation by reduction of a nitro group to the corresponding hydroxylamine (PR-104H) or amine (PR-104M). Metabolic reduction is catalysed by flavoreductases such as cytochrome P450 oxidoreductase (POR) under hypoxia, or by aldo-ketoreductase 1C3 (AKR1C3) independently of hypoxia. The unstable reduced metabolites are challenging to measure in biological samples, and biomarkers of the metabolic activation of PR-104A have not been used in the clinical evaluation of PR-104 to date. Here, we employ a selected reaction monitoring mass spectrometry assay for DNA crosslinks to assess the capacity of human cancer cells to bioactivate PR-104A. We also test whether the more abundant DNA monoadducts could be used for the same purpose. DNA monoadducts and crosslinks from PR-104A itself, and from its reduced metabolites, accumulated over 4 h in AKR1C3-expressing TF1 erythroleukaemia cells under hypoxia, whereas intracellular concentrations of unstable PR-104H and PR-104M reached steady state within 1 h. We then varied rates of PR-104A reduction by manipulating hypoxia or reductase expression in a panel of cell lines, in which AKR1C3 and POR were quantified by targeted proteomics. Hypoxia or reductase overexpression induced large increases in PR-104A sensitivity (inhibition of proliferation), DNA damage response (γH2AX formation), steady-state concentrations of PR-104H/M and formation of reduced drug-DNA adducts but not DNA adducts retaining the dinitro groups of PR-104A. The fold-change in the sum of PR-104H and PR-104M correlated with the fold-change in reduced crosslinks or monoadducts (R 2  = 0.87 for both), demonstrating their potential for assessing the capacity of cancer cells to bioactivate PR-104A. Copyright © 2018 Elsevier Inc. All rights reserved.

  9. Effects of experimental nitrogen fertilization on planktonic metabolism and CO2 flux in a hypereutrophic hardwater lake.

    Directory of Open Access Journals (Sweden)

    Matthew J Bogard

    Full Text Available Hardwater lakes are common in human-dominated regions of the world and often experience pollution due to agricultural and urban effluent inputs of inorganic and organic nitrogen (N. Although these lakes are landscape hotspots for CO2 exchange and food web carbon (C cycling, the effect of N enrichment on hardwater lake food web functioning and C cycling patterns remains unclear. Specifically, it is unknown if different eutrophication scenarios (e.g., modest non point vs. extreme point sources yield consistent effects on auto- and heterotrophic C cycling, or how biotic responses interact with the inorganic C system to shape responses of air-water CO2 exchange. To address this uncertainty, we induced large metabolic gradients in the plankton community of a hypereutrophic hardwater Canadian prairie lake by adding N as urea (the most widely applied agricultural fertilizer at loading rates of 0, 1, 3, 8 or 18 mg N L-1 week-1 to 3240-L, in-situ mesocosms. Over three separate 21-day experiments, all treatments of N dramatically increased phytoplankton biomass and gross primary production (GPP two- to six-fold, but the effects of N on autotrophs plateaued at ~3 mg N L-1. Conversely, heterotrophic metabolism increased linearly with N fertilization over the full treatment range. In nearly all cases, N enhanced net planktonic uptake of dissolved inorganic carbon (DIC, and increased the rate of CO2 influx, while planktonic heterotrophy and CO2 production only occurred in the highest N treatments late in each experiment, and even in these cases, enclosures continued to in-gas CO2. Chemical effects on CO2 through calcite precipitation were also observed, but similarly did not change the direction of net CO2 flux. Taken together, these results demonstrate that atmospheric exchange of CO2 in eutrophic hardwater lakes remains sensitive to increasing N loading and eutrophication, and that even modest levels of N pollution are capable of enhancing autotrophy and CO

  10. Ralstonia solanacearum uses inorganic nitrogen metabolism for virulence, ATP production, and detoxification in the oxygen-limited host xylem environment.

    Science.gov (United States)

    Dalsing, Beth L; Truchon, Alicia N; Gonzalez-Orta, Enid T; Milling, Annett S; Allen, Caitilyn

    2015-03-17

    that R. solanacearum rapidly depletes oxygen in host xylem but can then respire using host nitrate as a terminal electron acceptor. The microbe uses its denitrification pathway to detoxify the reactive nitrogen species nitrite (a product of nitrate respiration) and nitric oxide (a plant defense signal). Detoxification may play synergistic roles in bacterial wilt virulence by converting the host's chemical weapon into an energy source. Mutant bacterial strains lacking elements of the denitrification pathway could not grow as well as the wild type in tomato plants, and some mutants were also reduced in virulence. Our results show how a pathogen's metabolic activity can alter the host environment in ways that increase pathogen success. Copyright © 2015 Dalsing et al.

  11. Gene and genome-centric analyses of koala and wombat fecal microbiomes point to metabolic specialization for Eucalyptus digestion

    Directory of Open Access Journals (Sweden)

    Miriam E. Shiffman

    2017-11-01

    Full Text Available The koala has evolved to become a specialist Eucalyptus herbivore since diverging from its closest relative, the wombat, a generalist herbivore. This niche adaptation involves, in part, changes in the gut microbiota. The goal of this study was to compare koala and wombat fecal microbiomes using metagenomics to identify potential differences attributable to dietary specialization. Several populations discriminated between the koala and wombat fecal communities, most notably S24-7 and Synergistaceae in the koala, and Christensenellaceae and RF39 in the wombat. As expected for herbivores, both communities contained the genes necessary for lignocellulose degradation and urea recycling partitioned and redundantly encoded across multiple populations. Secondary metabolism was overrepresented in the koala fecal samples, consistent with the need to process Eucalyptus secondary metabolites. The Synergistaceae population encodes multiple pathways potentially relevant to Eucalyptus compound metabolism, and is predicted to be a key player in detoxification of the koala’s diet. Notably, characterized microbial isolates from the koala gut appear to be minor constituents of this habitat, and the metagenomes provide the opportunity for genome-directed isolation of more representative populations. Metagenomic analysis of other obligate and facultative Eucalyptus folivores will reveal whether putatively detoxifying bacteria identified in the koala are shared across these marsupials.

  12. Nutritive utilization of protein and digestive utilization of fat in two commercial diets designed for clinical enteral nutrition.

    Science.gov (United States)

    Alférez, M J; Campos, M S; Barrionuevo, M; López-Aliaga, I

    1990-01-01

    The digestive and metabolic utilization of protein (50% lactoalbumin + 50% casein) and fat (43.0% butter, 29.5% olive oil, 14.7% soy oil, 9.8% MCT and 3.0% lecithin) provided by two commercial diets used in clinical enteral nutrition (normoproteic, 16.1% protein and 20.8% fat, and hyperproteic, 23.1% protein and 14.9% fat), was studied in adult rats (mean body weight 180 g). The diet containing the greater amount of protein improved the digestive utilization of nitrogen, and although nitrogen retention was optimal, it failed to rise further when the dietary protein supply was increased. The digestive utilization of fat in both diets was excellent.

  13. Complexo enzimático para suínos: digestão, metabolismo, desempenho e impacto ambiental Enzyme complex for swine: nutrient digestion, metabolism, performance and environmental impact

    Directory of Open Access Journals (Sweden)

    Urbano dos Santos Ruiz

    2008-03-01

    energy, protein and amino acids levels. In the Exp 2, growth performance, production and composition of feces in total solids, volatile solids, nitrogen, macro and micro minerals, in relation to growth performance, were measured in barrows from 50 to 151 days of age and 18.34 ± 1.35 kg initial body weight. Three experimental diets were used, one formulated to meet or exceed the nutritional requirements of swine according to NRC (1998 and the others with reduced energy, protein and amino acids levels, with or without the enzyme complex. It was used a complete randomized block design. Dietary enzyme supplementation in feeds based mainly on corn and soybean meal did not improve nutrient digestibilities and growth performance neither reduced nutrient excretion in feces. More research is necessary to test new nutritional matrix and different levels of the enzyme complex.

  14. Increased iron availability resulting from increased CO2 enhances carbon and nitrogen metabolism in the economical marine red macroalga Pyropia haitanensis (Rhodophyta).

    Science.gov (United States)

    Chen, Binbin; Zou, Dinghui; Yang, Yufeng

    2017-04-01

    Ocean acidification caused by rising CO 2 is predicted to increase the concentrations of dissolved species of Fe(II) and Fe(III), leading to the enhanced photosynthetic carbon sequestration in some algal species. In this study, the carbon and nitrogen metabolism in responses to increased iron availability under two CO 2 levels (390 μL L -1 and 1000 μL L -1 ), were investigated in the maricultivated macroalga Pyropia haitanensis (Rhodophyta). The results showed that, elevated CO 2 increased soluble carbonhydrate (SC) contents, resulting from enhanced photosynthesis and photosynthetic pigment synthesis in this algae, but declined its soluble protein (SP) contents, resulting in increased ratio of SC/SP. This enhanced photosynthesis performance and carbon accumulation was more significant under iron enrichment condition in seawater, with higher iron uptake rate at high CO 2 level. As a key essential biogenic element for algae, Fe-replete functionally contributed to P. haitanensis photosynthesis. Increased SC fundamentally provided carbon skeletons for nitrogen assimilation. The significant increase of carbon and nitrogen assimilation finally contributed to enhanced growth in this alga. This was also intuitively reflected by respiration that provided energy for cellular metabolism and algal growth. We propose that, in the predicted scenario of rising atmospheric CO 2 , P. haitanensis is capable to adjust its physiology by increasing its carbon and nitrogen metabolism to acclimate the acidified seawater, at the background of global climate change and simultaneously increased iron concentration due to decreased pH levels. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Digestibilidade dos compostos nitrogenados insolúveis em detergente ácido em bovinos manejados em pastagem de capim-braquiária Digestibility of acid detergent insoluble nitrogen in cattle grazing signalgrass

    Directory of Open Access Journals (Sweden)

    Edenio Detmann

    2006-08-01

    Full Text Available Objetivou-se neste estudo avaliar as digestibilidades total e parcial dos compostos nitrogenados insolúveis em detergente ácido (NIDA em bovinos em pastejo. Foram utilizados cinco novilhos mestiços Holandês x Zebu (24 meses de idade e 304 kg de PV, canulados no esôfago, rúmen e abomaso, manejados em cinco piquetes de Brachiaria decumbens (0,34 ha, recebendo ou não suplementação com concentrado. O experimento foi realizado em quatro períodos experimentais de 21 dias, entre agosto e novembro de 2000. A avaliação da forragem selecionada pelos animais foi feita em amostras de extrusa esofágica e a estimativa do consumo e dos fluxos fecais e abomasais de MS e NIDA, foram estimados por intermédio de indicadores interno e externo. A avaliação estatística da digestibilidade do NIDA foi conduzida por ajustamento de equação de regressão linear, desconsiderando o parâmetro intercepto e utilizando-se como variáveis independente e dependente as estimativas de influxo e efluxo de NIDA, respectivamente. Os desvios do coeficiente de regressão a partir do valor paramétrico 1,0 foram considerados estimativas de digestibilidade. A comparação entre o consumo e os fluxos abomasal e fecal de NIDA indicou haver digestibilidade desta fração em nível total, atribuída exclusivamente a eventos intestinais (30,7%, uma vez que não foi observada digestibilidade no compartimento ruminal. Esse comportamento indica que o teor de NIDA de um alimento é somente indicador, e não preditor, da digestibilidade potencial dos compostos nitrogenados totais.The objective of this trial was to investigate ruminal, intestinal and total tract digestibility of acid detergent insoluble nitrogen (ADIN in grazing cattle. Five Holstein x Zebu steers averaging 304 kg of body weight and 24 months of age and fitted with esophageal, ruminal and abomasal cannulas were used in this study. Animals were maintained in five 0.34-ha paddocks of Brachiaria decumbens with or

  16. Effects of adding food by-products mainly including noodle waste to total mixed ration silage on fermentation quality, feed intake, digestibility, nitrogen utilization and ruminal fermentation in wethers.

    Science.gov (United States)

    Ishida, Kyohei; Yani, Srita; Kitagawa, Masayuki; Oishi, Kazato; Hirooka, Hiroyuki; Kumagai, Hajime

    2012-11-01

    Four wethers were used in a 4 × 4 Latin square design experiment to evaluate the applicability of two types of total mixed ration (TMR) silage with food by-products. Four food by-products (i.e., potato waste, soy sauce cake, soybean curd residue and noodle waste) were obtained and mixed with commercial concentrate (CC) as TMR silage. The two types of TMR silage, T1 and T2, each contained CC, in addition to all by-products for T1 (TRE1), and soy sauce cake and noodle waste for T2 (TRE2) on a dry matter (DM) basis. The silage was well-fermented with low pH values and high lactic acid concentration. As the experimental treatments, T1, T2 and CC (CTL) were fed with a basal diet. The result showed that the digestibility of DM and organic matter (OM) were higher for T1 than for CC (P < 0.05), while crude protein digestibility was not significantly different among T1, T2 and CC. The retained nitrogen was not affected by inclusion of food by-products. Ruminal pH in TRE1 and TRE2 immediately decreased compared to that in CTL. The study suggested that the two types of TMR silage, including food by-products, might be used as a substitute for commercial concentrate. © 2012 The Authors. Animal Science Journal © 2012 Japanese Society of Animal Science.

  17. Nutrient Intake and Digestibility in Merino Sheep Fed Peanut Straw

    Science.gov (United States)

    Hanim, C.; Muhlisin

    2018-02-01

    This study aimed to compare nutrient intake and digestibility between male and female Merino fed peanut straw as sole feed. Four male and five female Merino sheep ages 10 to 12 month with average weight of 40 kg were used in this study. All animals were confined in individual metabolism cages and nylon nets were fitted bellow the cages for faecal collection. This experiment was done with 14 d adaptation period and 7 d collection period. Representative sample of feed, refusal feed, and faeces were analysed proximate including dry matter (DM), organic matter (OM), crude protein (CP), crude fibre (CF), ether extract (EE), and extract-free nitrogen (EFN). Data collected were used to calculate nutrient intake and digestibility. All nutrient intake in male Merino was higher (Pdigestibility of DM, CP, and CF in male Merino sheep were higher (Pdigestibility.

  18. Valor nutritivo do resíduo da indústria processadora de abacaxi (Ananas comosus L. em dietas para ovinos. 1. Consumo, digestibilidade aparente e balanços energético e nitrogenado Nutritive value of pineapple by-product (Ananas comosus L. in diets for sheep. 1. Intake, apparent digestibility, energetic and nitrogenous balance

    Directory of Open Access Journals (Sweden)

    M.C.P. Rogério

    2007-06-01

    Full Text Available O presente estudo foi conduzido para avaliar a influência da inclusão do resíduo do processamento de abacaxi (Ananas comosus L. nas dietas sobre os consumos (por unidade de tamanho metabólico - UTM e coeficientes de digestibilidade da matéria seca (MS, matéria orgânica (MO, proteína bruta (PB, extrato etéreo (EE, fibra detergente neutro (FDN, fibra detergente ácido (FDA, hemiceluloses (HCEL, celulose (CEL e energia de dietas experimentais isofibrosas e isoprotéicas. Avaliaram-se também os balanços nitrogenados e de energia dos animais. Vinte ovinos machos, inteiros receberam rações com quatro níveis de inclusão do resíduo (0; 11%; 16%; 27% em base de matéria seca, em delineamento inteiramente ao acaso, com cinco repetições por tratamento. Maiores consumos de matéria seca foram evidenciados quando as rações continham 11% do resíduo. Maiores consumos de proteína bruta, fibra detergente neutro, fibra detergente ácido e celulose (g/UTM e energia metabolizável (kcal/UTM foram apresentados por animais alimentados com dietas contendo 11% de resíduo em relação ao das dietas com 27% de inclusão (PThe influence of increasing levels of pineapple by-product (Ananas comosus L. on intake (unit metabolic size - UMS and apparent digestibility (% of dry matter (DM, organic matter (OM, crude protein (CP, ether extract (EE, neutral detergent fiber (NDF, acid detergent fiber (ADF, hemicelluloses (HCEL and cellulose (CEL and energy of isofibrous and isoproteic experimental diets of sheep were evaluated. Energetic and nitrogenous balance were also measured. Twenty rams were randomly allotted to four treatments in a completely randomized design with five replications. The treatments were formulated to contain zero; 11, 16 and 27% of pineapple by-product on DM basis. Higher dry matter intake was observed on 11% pineapple by-product diet. CP, NDF, ADF, CEL intake (g/UMS and metabolizable energy intake (kcal/UMS of 11% pineapple by

  19. Dietary carbohydrate deprivation increases 24-hour nitrogen excretion without affecting postabsorptive hepatic or whole body protein metabolism in healthy men

    NARCIS (Netherlands)

    Bisschop, PH; de Sain-van der Velden, MGM; Stellaard, F; Kuipers, F; Meijer, AJ; Sauerwein, HP; Romijn, JA

    Because insulin is an important regulator of protein metabolism, we hypothesized that physiological modulation of insulin secretion, by means of extreme variations in dietary carbohydrate content, affects postabsorptive protein metabolism. Therefore, we studied the effects of three isocaloric diets

  20. Dietary carbohydrate deprivation increases 24-hour nitrogen excretion without affecting postabsorptive hepatic or whole body protein metabolism in healthy men

    NARCIS (Netherlands)

    Bisschop, P. H.; de Sain-van der Velden, M. G. M.; Stellaard, F.; Kuipers, F.; Meijer, A. J.; Sauerwein, H. P.; Romijn, J. A.

    2003-01-01

    Because insulin is an important regulator of protein metabolism, we hypothesized that physiological modulation of insulin secretion, by means of extreme variations in dietary carbohydrate content, affects postabsorptive protein metabolism. Therefore, we studied the effects of three isocaloric diets

  1. Metabolism

    Science.gov (United States)

    ... lin), which signals cells to increase their anabolic activities. Metabolism is a complicated chemical process, so it's not ... how those enzymes or hormones work. When the metabolism of body chemicals is ... Hyperthyroidism (pronounced: hi-per-THIGH-roy-dih-zum). Hyperthyroidism ...

  2. Intake and total apparent digestibility in lambs fed six maize varieties in the Brazilian Semiarid

    Directory of Open Access Journals (Sweden)

    Rafael Dantas dos Santos

    2011-12-01

    Full Text Available The objective of this study was to evaluate the daily intake and total apparent digestibility of dry matter, organic matter, crude protein, gross energy, ether extract, neutral detergent fiber, acid detergent fiber, total and non-fibrous carbohydrates, total digestible nutrients, energy intake and nitrogen balance of silages of six maize varieties with early or super early cycles recommended to Northeast Brazil. Twenty-four male castrated lambs were lodged in metabolic cages. A completely randomized design with six treatments and four replications was used, with means compared by Tukey test at 5%. There were no differences among varieties for any of the evaluated variables regarding intake and apparent digestibility. Concerning the intake of digestible energy, metabolizable energy and the ratio content of digestible and metabolizable energy, significant differences were observed between varieties and BRS Assum Preto showed highest values of metabolizable energy (2.650,8 kcal/day. All of the treatments presented positive nitrogen balance and did not differ among themselves. The varieties asessed can be an additional option to the semiarid regions in Brazil.

  3. Evaluation of the pepsin digestibility assay for predicting amino acid digestibility of meat and bone meals.

    Science.gov (United States)

    Davis, T M; Parsons, C M; Utterback, P L; Kirstein, D

    2015-05-01

    Sixteen meat and bone meal (MBM) samples were obtained and selected from various company plants to provide a wide range in pepsin nitrogen digestibility values. Pepsin digestibility was determined using either 0.02 or 0.002% pepsin. Amino acid (AA) digestibility of the 16 MBM samples was then determined using a precision-fed cecectomized rooster assay. The 0.02% pepsin digestibility values were numerically higher than the 0.002% pepsin values. The values varied from 77 to 93% for 0.02% pepsin and from 67 to 91% for 0.002% pepsin. The rooster AA digestibility results showed a wide range of values among MBM samples mostly due to the 4 samples having lowest and highest AA digestibility. A precision-fed broiler chick ileal AA digestibility assay confirmed that there were large differences in AA digestibility among the MBM samples having the lowest and highest rooster digestibility values. Correlation analyses between pepsin and AA digestibility values showed that the correlation values (r) were highly significant (P digestibility values were not included in the correlation analyses, the correlation coefficient values (r) were generally very low and not significant (P > 0.05). The results indicated that the pepsin nitrogen digestibility assay is only useful for detecting large differences in AA digestibility among MBM. There also was no advantage for using 0.02 versus 0.002% pepsin. © 2015 Poultry Science Association Inc.

  4. Digestibility, faeces recovery, and related carbon, nitrogen and phosphorus balances of five feed ingredients evaluated as fishmeal alternatives in Nile tilapia, Oreochromis niloticus L.

    NARCIS (Netherlands)

    Schneider, O.; Amirkolaie, A.K.; Vera-Cartas, J.; Eding, E.H.; Schrama, J.W.; Verreth, J.A.J.

    2004-01-01

    This study shows that alternatives for fishmeal in a fish diet affect not only fish growth but also faeces stability and nitrogen (N) and phosphorus (P) waste production. Wheat gluten diet (WGD), soybean meal extract diet (SBE), soybean meal diet (SBM), duckweed diet (DWD) and single-cell protein

  5. Recent Advance in Division of Carbohydrate and Protein Fractions of Ruminant Feed and Their Metabolism in Digestive Tract

    Institute of Scientific and Technical Information of China (English)

    Xiaohua; PAN; Liang; YANG; Hairui; XIN; Benhai; XIONG

    2016-01-01

    Accurate assessment of feed’s Carbohydrate( CHO) and protein nutritional values and rumen metabolism are significant for dairy production. Cornell Net Carbohydrate and Protein System( CNCPS) as an important method to evaluate feedstuff nutritional values,hasn’t been widely used in China. In order to illustrate updates of CNCPS systems deeply,the following sections were reviewed:( i) CHO and protein fractions were updated,CA was subdivided into CA1,CA2,CA3 and CA4 in CNCPS v6. 1,protein was reclassified into PA1,PA2,PB1,PB2 and PC after CNCPS v6. 1. Content of CHO and protein fractions vary in different feedstuff and affected by feed processing;( ii) Degradation rates( Kd) values for the new CA expanded scheme were updated to 0,7,5,40- 60 % h-1respectively,Kd for PA and PB1 decreased to 200 % h-1and 10- 40 % h-1;( iii) Equations for passage rate( Kp) initially includes Kpf( Kp of forages) and Kpc( Kp of concentrates),and adjusted by effective NDF( e NDF),while in CNCPS v5. 0,Kpl( Kp of liquids) equation was added and e NDF was replaced by physically effective NDF( pe NDF). In CNCPS v6. 1,Fp BW and Cp BW were integrated into Kp equations and pe NDF was abandoned.( iv)The relationship and difference among Weende system of proximate analysis,Van Soest fiber analysis[35],NRC( 2001)[28]and CNCPS were analyzed. The first two systems laid the foundation for NRC( 2001) and CNCPS system. The latter two systems are different in CHO and protein division,also NRC( 2001) developed separate Kp equations for wet and dry forages but no equation for Kpl. CNCPS developed a Kp equation that work for wet and dry forages,and Kpl equation was established. In conclusion,the division and development of CHO and protein fractions,the update of Kd and Kp equation were reviewed systematically.

  6. Methods of clinical chemistry and isotopic technique for investigation of the nitrogen metabolism in man using 15N

    International Nuclear Information System (INIS)

    Faust, H.; Bornhak, H.; Hirschberg, K.; Jung, K.; Junghans, P.; Krumbiegel, P.; Reinhardt, R.

    1981-03-01

    The present manual is a catalogue of methods representing theoretical and practical aspects of application of the stable isotope 15 N in medicine as well as a reference book for users of 15 N techniques in life sciences. Special emphasis is given to the planning of 15 N tracer experiments and their interpretation, sources of error and standard values of nitrogen compounds, information on sampling of medical materials, methods of separation and determination of proteins and non-protein nitrogen compounds in serum and urine, and details of the isotopic analysis of nitrogen by emission and mass spectrometry. (author)

  7. Metabolism of organic acids, nitrogen and amino acids in chlorotic leaves of 'Honeycrisp' apple (Malus domestica Borkh) with excessive accumulation of carbohydrates.

    Science.gov (United States)

    Wang, Huicong; Ma, Fangfang; Cheng, Lailiang

    2010-07-01

    Metabolite profiles and activities of key enzymes in the metabolism of organic acids, nitrogen and amino acids were compared between chlorotic leaves and normal leaves of 'Honeycrisp' apple to understand how accumulation of non-structural carbohydrates affects the metabolism of organic acids, nitrogen and amino acids. Excessive accumulation of non-structural carbohydrates and much lower CO(2) assimilation were found in chlorotic leaves than in normal leaves, confirming feedback inhibition of photosynthesis in chlorotic leaves. Dark respiration and activities of several key enzymes in glycolysis and tricarboxylic acid (TCA) cycle, ATP-phosphofructokinase, pyruvate kinase, citrate synthase, aconitase and isocitrate dehydrogenase were significantly higher in chlorotic leaves than in normal leaves. However, concentrations of most organic acids including phosphoenolpyruvate (PEP), pyruvate, oxaloacetate, 2-oxoglutarate, malate and fumarate, and activities of key enzymes involved in the anapleurotic pathway including PEP carboxylase, NAD-malate dehydrogenase and NAD-malic enzyme were significantly lower in chlorotic leaves than in normal leaves. Concentrations of soluble proteins and most free amino acids were significantly lower in chlorotic leaves than in normal leaves. Activities of key enzymes in nitrogen assimilation and amino acid synthesis, including nitrate reductase, glutamine synthetase, ferredoxin and NADH-dependent glutamate synthase, and glutamate pyruvate transaminase were significantly lower in chlorotic leaves than in normal leaves. It was concluded that, in response to excessive accumulation of non-structural carbohydrates, glycolysis and TCA cycle were up-regulated to "consume" the excess carbon available, whereas the anapleurotic pathway, nitrogen assimilation and amino acid synthesis were down-regulated to reduce the overall rate of amino acid and protein synthesis.

  8. Desempenho, digestibilidade e balanço de nitrogênio em cordeiros alimentados com silagem de milho ou cana-de-açúcar e dois níveis de concentrado Performance, digestibility and nitrogen balance of lambs fed corn silage or sugar cane based diets with two levels of concentrate

    Directory of Open Access Journals (Sweden)

    Greicy Mitzi Bezerra Moreno

    2010-04-01

    the daily weight gain and food conversion. Simultaneously, it was carried out digestibility and metabolism trials to determine the nutrient intake and digestibility and nitrogen balance of the experiment diets. The weight gain (294.6 g/day was higher for the lambs fed corn silage, and regarding to roughage:concentrate 40:60 it was 314.3 g/day. The ratio roughage:concentrate only influenced the consume of digestible fiber in neutral detergent (NDF and fiber in acid detergent (FAD in which the highest values, 125.26 and 48.97 g/day obtained with the ratio roughage:concentrate 60:40. The lambs fed corn silage showed a higher intake of all digestible nutrients, except for crude protein (162.00 g/day and non fibrous carbohydrates (471.42 g/day. The highest digestibility of organic matter (80.34% and total carbohydrates (80.71% were obtained with the 40:60 ratio and those of dry matter (78.91%, crude protein (81.30% and gross energy (78.77% were obtained for the lambs fed sugar cane. The highest values for ingested, absorbed and retained nitrogen, 32.6, 20.5 and 13.7 g/day, respectively, were observed in diets with 40% of roughage. The type of roughage influences more the nutrient digestibility than its proportion in the diet.

  9. The effects of added sulphur amino acids, threonine and an ideal amino acid ratio on nitrogen metabolism in mature, overweight dogs.

    Science.gov (United States)

    Bohaty, Robin E; de Godoy, Maria R C; McLeod, Kyle R; Harmon, David L

    2012-02-01

    The objectives of this study were to investigate the effects of added essential amino acids in conjunction with a dietary lysine/MJ of 0.72 on nitrogen (N) metabolism in dogs. Treatments were; a control diet, a diet that provided an ideal amino acid profile (IAA), a diet with added total sulphur amino acids (TSAA), and a diet with added TSAA and threonine (TT). Diets were fed to eight overweight, mature, female hounds using a replicated 4 x 4 Latin Square design. Food intake was similar across treatments, however, food N intake was higher (p dogs formulated to provide a 0.72 g lysine/MJ ME ratio.

  10. Growth, photosynthesis and nitrogen metabolism in soybean varieties after exclusion of the UV-B and UV-A/B components of solar radiation

    OpenAIRE

    Sanjay Singh Baroniya; Sunita Kataria; Govind Prakash Pandey; Kadur N. Guruprasad

    2014-01-01

    A field experiment was conducted to study the impact of the exclusion of the solar UV components on growth, photosynthesis and nitrogen metabolism in soybean (Glycine max) varieties PK-472, Pusa-24, JS 71-05, JS-335, NRC-7 and Kalitur. The plants were grown in specially designed UV exclusion chambers wrapped with filters to exclude UV-B or UV-A/B and transmitted all UV. Exclusion of UV significantly enhanced the growth of the aerial parts as well as the growth of the below ground parts in all...

  11. Early-warning process/control for anaerobic digestion and biological nitrogen transformation processes: Batch, semi-continuous, and/or chemostat experiments. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Hickey, R. [Science Applications International Corp., McLean, VA (United States)

    1992-09-01

    The objective of this project was to develop and test an early-warning/process control model for anaerobic sludge digestion (AD). The approach was to use batch and semi-continuously fed systems and to assemble system parameter data on a real-time basis. Specific goals were to produce a real-time early warning control model and computer code, tested for internal and external validity; to determine the minimum rate of data collection for maximum lag time to predict failure with a prescribed accuracy and confidence in the prediction; and to determine and characterize any trends in the real-time data collected in response to particular perturbations to feedstock quality. Trends in the response of trace gases carbon monoxide and hydrogen in batch experiments, were found to depend on toxicant type. For example, these trace gases respond differently for organic substances vs. heavy metals. In both batch and semi-continuously feed experiments, increased organic loading lead to proportionate increases in gas production rates as well as increases in CO and H{sub 2} concentration. An analysis of variance of gas parameters confirmed that CO was the most sensitive indicator variable by virtue of its relatively larger variance compared to the others. The other parameters evaluated including gas production, methane production, hydrogen, carbon monoxide, carbon dioxide and methane concentration. In addition, a relationship was hypothesized between gaseous CO concentration and acetate concentrations in the digester. The data from semicontinuous feed experiments were supportive.

  12. Improvement of anaerobic digestion performance by continuous nitrogen removal with a membrane contactor treating a substrate rich in ammonia and sulfide.

    Science.gov (United States)

    Lauterböck, B; Nikolausz, M; Lv, Z; Baumgartner, M; Liebhard, G; Fuchs, W

    2014-04-01

    The effect of reduced ammonia levels on anaerobic digestion was investigated. Two reactors were fed with slaughterhouse waste, one with a hollow fiber membrane contractor for ammonia removal and one without. Different organic loading rates (OLR) and free ammonia and sulfide concentrations were investigated. In the reactor with the membrane contactor, the NH4-N concentration was reduced threefold. At a moderate OLR (3.1 kg chemical oxygen demand - COD/m(3)/d), this reactor performed significantly better than the reference reactor. At high OLR (4.2 kg COD/m(3)/d), the reference reactor almost stopped producing methane (0.01 Nl/gCOD). The membrane reactor also showed a stable process with a methane yield of 0.23 Nl/g COD was achieved. Both reactors had predominantly a hydrogenotrophic microbial consortium, however in the membrane reactor the genus Methanosaeta (acetoclastic) was also detected. In general, all relevant parameters and the methanogenic consortium indicated improved anaerobic digestion of the reactor with the membrane. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Aquaporins in Digestive System.

    Science.gov (United States)

    Zhu, Shuai; Ran, Jianhua; Yang, Baoxue; Mei, Zhechuan

    2017-01-01

    In this chapter, we mainly discuss the expression and function of aquaporins (AQPs ) expressed in digestive system . AQPs in gastrointestinal tract include four members of aquaporin subfamily: AQP1, AQP4, AQP5 and AQP8, and a member of aquaglyceroporin subfamily: AQP3. In the digestive glands, especially the liver, we discuss three members of aquaporin subfamily: AQP1, AQP5 and AQP8, a member of aquaglyceroporin subfamily: AQP9. AQP3 is involved in the diarrhea and inflammatory bowel disease; AQP5 is relevant to gastric carcinoma cell proliferation and migration; AQP9 plays considerable role in glycerol metabolism , urea transport and hepatocellular carcinoma. Further investigation is necessary for specific locations and functions of AQPs in digestive system.

  14. Vinasse labelling with sup(15)N: use in mineral plants fertilization studies and the potential of the isotopic technique in studies of fermentative nitrogen metabolism of wine

    International Nuclear Information System (INIS)

    Lara C, W.A.; Trivelin, P.C.O.; Basso, L.C.

    1991-01-01

    A methodology for vinasse sup(15)N enrichment was developed under laboratory conditions through a fermentative process. Direct addition of sup(15)N-(NH sub(4)) sub(2)SO sub(4) 90.39 atoms % to the vintage tub (FESA procedure) was compared to the use of a previously enrichment sup(15)N yeast (FELE procedure) by the addition of the label to the multiplicative medium. The mean metabolic recovery of the tracer from the vinasse after fermentation was 4.2 and 11.1% per cycle and accumulated recovery was 3.4 and 33.3%, respectively for the FESA and FELE procedures. The potential of the use of sup(15)N label in studies of fermentative nitrogen metabolism is illustrated by the quantification of sup(15)N distribution among recycled yeast and wine. (author)

  15. Relationships between dry matter content, ensiling, ammonia-nitrogen, and ruminal in vitro starch digestibility in high-moisture corn samples.

    Science.gov (United States)

    Ferraretto, L F; Taysom, K; Taysom, D M; Shaver, R D; Hoffman, P C

    2014-05-01

    The objectives of the study were (1) to determine relationships between high-moisture corn (HMC) dry matter (DM), ammonia-N [% of crude protein (CP)], and soluble CP concentrations, and pH, with 7-h ruminal in vitro starch digestibility (ivStarchD), and (2) to evaluate the effect of ensiling on pH, ammonia-N, soluble CP, and ivStarchD measurements in HMC. A data set comprising 6,131 HMC samples (55 to 80% DM) obtained from a commercial feed analysis laboratory was used for this study. Month of sample submittal was assumed to be associated with length of the ensiling period. Data for month of sample submittal were analyzed using Proc Mixed in SAS (SAS Institute Inc., Cary, NC) with month as a fixed effect. Regressions to determine linear and quadratic relationships between ivStarchD and ammonia-N, soluble CP, pH, and DM content were performed using Proc Mixed. The ivStarchD increased by 9 percentage units from October to August of the following year. Similar results were observed for ammonia-N and soluble CP with increases from 1.8 to 4.6% of CP and 31.3 to 46.4% of CP, respectively, from October to August of the following year. Ammonia-N was positively related to ivStarchD (R(2)=0.61). The DM content of HMC at silo removal was negatively related (R(2)=0.47) to ivStarchD with a decrease of 1.6 percentage units in ivStarchD per 1-percentage-unit increase in DM content. The pH of HMC was negatively related to ammonia-N (R(2)=0.53), soluble CP (R(2)=0.57), and ivStarchD (R(2)=0.51). Combined, ammonia-N, DM, soluble CP, and pH provided a good prediction of ivStarchD (adjusted R(2)=0.70). Increasing pH, ammonia-N, soluble CP, and ivStarchD values indicate that HMC may need up to 10 mo of ensiling to reach maximum starch digestibility. Ammonia-N, DM content, soluble CP concentration, and pH are good indicators of ruminal in vitro starch digestibility for high-moisture corn. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights

  16. Effect of vermicompost on some physiological attributes involved in carbon and nitrogen metabolism as well as nutrient status in leaves of tobacco (nicotiana tabacum L.)

    International Nuclear Information System (INIS)

    Qin, C.; Zheng, P.; Akram, N.A.

    2016-01-01

    A pot experiment was carried out to examine the influence of vermicompost application on some key enzymes and metabolites involved in carbon (C) and nitrogen (N) metabolism as well as nutrient status in the leaves of tobacco (Nicotiana tabacum L.). Two types of vermicompost with two application rates were used in this study. Regardless of application rate, both types of vermicompost significantly increased total N, phosphorus (P) and potassium (K) contents in the leaves. They also caused enhancements in contents of total soluble carbohydrates, reducing sugars, starch and total organic C as well as amylase and invertase activities involved in C metabolism, contents of soluble protein and nicotine in N metabolism in the leaves. With an increase in application rate, each vermicompost type had an increasing effect on almost all measured parameters except nitrate reductase activity. Regardless of vermicompost type, the high rate (50%) of application showed the best effects compared with controls. The effects of V1 type vermicompost were superior to those of V2 at the same application rate. Therefore, the above effects might appear to be dependent on both type and dose. Vermicompost could be considered as an effective organic matter for attaining improved plant nutrition as well as C and N metabolism. (author)

  17. Effects of supplementary desalted mother liquor as replacement of commercial salt in diet for Thai native cattle on digestibility, energy and nitrogen balance, and rumen conditions.

    Science.gov (United States)

    Sato, Yoshiaki; Angthong, Wanna; Butcha, Patima; Takeda, Motoharu; Oishi, Kazato; Hirooka, Hiroyuki; Kumagai, Hajime

    2018-05-16

    Four Thai native cattle were used in a 4 × 4 Latin square design experiment to evaluate the availability of desalted mother liquor (DML) as replacement of salt in concentrate. Each cattle was assigned to one of the following concentrate feeding treatments: C1, 1% NaCl was added as salt; C2, 2% NaCl was added as salt; D1, 1% NaCl was replaced by DML; D2, 2% NaCl was replaced by DML, on a dry matter (DM) basis. The animals were fed rice straw and experimental concentrates (40:60) at 1.9% of body weight on a DM basis, daily. Acid detergent fiber expressed exclusive of residual ash (ADFom) digestibility in DML treatment was higher than salt treatment (p balance, rumen conditions, blood metabolites and methane emission. © 2018 Japanese Society of Animal Science.

  18. Effects of Different Roughage to Concentrate Ratios on Ruminal Fermentation Characteristics,Hutrients Digestion and Metabolism of Jinnan Cattle%不同精粗比饲粮对晋南牛瘤胃发酵特性和养分消化代谢的影响

    Institute of Scientific and Technical Information of China (English)

    张莹莹; 王聪; 刘强; 白元生; 师周戈; 刘晓妮; 高书文

    2014-01-01

    period. After that,three heads of cattle were randomly selected from each group for a 10-day digestion and metabolism trial. The results showed that average daily gain in test group Ⅲ was significantly higher than that in control group and test group Ⅰ( P<0.05),and dry matter intake and feed∶gain in test group Ⅲ were significantly lower than those in control group and test groupⅠ( P<0.05);the apparent digestibility of organ-ic matter and crude protein in test groups Ⅱ and Ⅲ were significantly higher than those in control group and test groupⅠ( P<0.05),and the apparent digestibility of dry matter in test groups was significantly higher than that in control group( P<0.05);nitrogen intake,digestible nitrogen and nitrogen retention in test groups Ⅱand Ⅲ were significantly higher than those in control group and test groups Ⅰ( P<0.05);nitrogen emission/nitrogen intake,phosphorus emission/phosphorus intake and methane energy emission in test group Ⅲ were significantly lower than those in control group,test groups Ⅰ and Ⅱ( P<0.05);the concentrations of total volatile fatty acid,propionate and butyrate of ruminal fluid in test groups Ⅱ and Ⅲ were significantly higher than those in control group and test groupⅠ( P<0.05),however,pH,acetate concentration,acetate ∶ propi-onate and ammonia nitrogen concentration of ruminal fluid in test groups Ⅱ and Ⅲ were significantly lower than those in control group and test groupⅠ( P<0.05). In conclusion,the optimal roughage to concentrate ra-tio in diet for finishing Jinnan cattle is 70∶30.

  19. Evaluation of Kjeldahl digestion method

    International Nuclear Information System (INIS)

    Amin, M.; Flowers, T.H.

    2004-01-01

    The evaluation of the Kjeldahl digestion method was investigated by comparing measured values of total nitrogen, phosphorus and potassium using three salt and catalyst mixture in Standard Kjeldahl digestion method and Salicyclic acid Modification method with certified values of plant material as well as comparison was made for determination of total nitrogen from steam distillation method verses the Technicon Auto-analyzer, and phosphorus Ascorbic acid/Molybdate method verses Molybdate/ Metavanadate method on the Technicon Auto-Analyzer. The 1 g salt/catalyst mixture recovered less nitrogen than the 2.5 g in the standard Kjeldahl method due to the lower temperature and incomplete digestion in both plant and soil samples. The 2.5 g catalyst mixture partially recovered nitrate in the standard Kjeldahl method and the salicylic acid modification fail to recover all over nitrate in plant material. Use of 2.5 g salt catalyst mixture and selenium appears to promote nitrogen losses in salicylic acid modification method but not in the standard Kjeldahl method of digestion for soil samples. No interference of selenium or copper was observed in Nitrogen and Phosphorus on calorimetric determination. The standard Kjeldahl method with 2.5 g of salt/catalyst mixture of sodium sulphate copper sulphate (10:1) in 5 ml sulfuric acid were found suitable for determination of total Nitrogen, phosphorus and potassium. The steam distillation and the Technicon Auto-Analyzer technique measure similar amounts of ammonium nitrogen. However, the Technicon Auto analyzer technique is easier, rapid, higher degree of reproducibility, precise, accurate, reliable and free from human error. The amount of phosphorus measured by the Ascorbic acid/Molybdate method was more accurate than by the Molybdate/Metavanadate method on Technicon Auto-Analyzer. (author)

  20. Interactions between barley grain processing and source of supplemental dietary fat on nitrogen metabolism and urea-nitrogen recycling in dairy cows.

    Science.gov (United States)

    Gozho, G N; Hobin, M R; Mutsvangwa, T

    2008-01-01

    The objective of this study was to determine the effects of methods of barley grain processing and source of supplemental fat on urea-N transfer to the gastrointestinal tract (GIT) and the utilization of this recycled urea-N in lactating dairy cows. Four ruminally cannulated Holstein cows (656.3 +/- 27.7 kg of BW; 79.8 +/- 12.3 d in milk) were used in a 4 x 4 Latin square design with 28-d periods and a 2 x 2 factorial arrangement of dietary treatments. Experimental diets contained dry-rolled barley or pelleted barley in combination with whole canola or whole flaxseed as supplemental fat sources. Nitrogen balance was measured from d 15 to 19, with concurrent measurements of urea-N kinetics using continuous intrajugular infusions of [15N 15N]-urea. Dry matter intake and N intake were higher in cows fed dry-rolled barley compared with those fed pelleted barley. Nitrogen retention was not affected by diet, but fecal N excretion was higher in cows fed dry-rolled barley than in those fed pelleted barley. Actual and energy-corrected milk yield were not affected by diet. Milk fat content and milk fat yield were higher in cows fed dry-rolled barley compared with those fed pelleted barley. Source of supplemental fat did not affect urea-N kinetics. Urea-N production was higher (442.2 vs. 334.3 g of N/d), and urea-N entering the GIT tended to be higher (272.9 vs. 202.0 g of N/d), in cows fed dry-rolled barley compared with those fed pelleted barley. The amount of urea-N entry into the GIT that was returned to the ornithine cycle was higher (204.1 vs. 159.5 g of N/d) in cows fed dry-rolled barley than in pelleted barley-fed cows. The amount of urea-N recycled to the GIT and used for anabolic purposes, and the amounts lost in the urine or feces were not affected by dietary treatment. Microbial nonammonia N supply, estimated using total urinary excretion of purine derivatives, was not affected by diet. These results show that even though barley grain processing altered urea

  1. Long-term exposure to slightly elevated air temperature alleviates the negative impacts of short term waterlogging stress by altering nitrogen metabolism in cotton leaves.

    Science.gov (United States)

    Wang, Haimiao; Chen, Yinglong; Xu, Bingjie; Hu, Wei; Snider, John L; Meng, Yali; Chen, Binglin; Wang, Youhua; Zhao, Wenqing; Wang, Shanshan; Zhou, Zhiguo

    2018-02-01

    Short-term waterlogging and chronic elevated temperature occur frequently in the Yangtze River Valley, yet the effects of these co-occurring environments on nitrogen metabolism of the subtending leaf (a major source leaf for boll development) have received little attention. In this study, plants were exposed to two temperature regimes (31.6/26.5 °C and 34.1/29.0 °C) and waterlogging events (0 d, 3 d, 6 d) during flowering and boll development. The results showed that the effects of waterlogging stress and elevated temperature in isolation on nitrogen metabolism were quite different. Waterlogging stress not only limited NR (EC 1.6.6.1) and GS (EC 6.3.1.2) activities through the down-regulation of GhNR and GhGS expression for amino acid synthesis, but also promoted protein degradation by enhanced protease activity and peptidase activity, leading to lower organ and total biomass (reduced by 12.01%-27.63%), whereas elevated temperature inhibited protein degradation by limited protease activity and peptidase activity, promoting plant biomass accumulation. Furthermore, 2-3 °C chronic elevated temperature alleviated the negative impacts of a brief (3 d) waterlogging stress on cotton leaves, with the expression of GhNiR up-regulated, the activities of NR, GS and GOGAT (EC 1.4.7.1) increased and the activities of protease and peptidase decreased, leading to higher protein concentration and enhanced leaf biomass for EW 3 relative to AW 3 . The results of the study suggested that exposure to slightly elevated air temperature improves the cotton plants' ability to recover from short-term (3 d) waterlogging stress by sustaining processes associated with nitrogen assimilation. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. The influence of straw meal on the crude protein and amino acid metabolism and the digestibility of crude nutrients in broiler hens. 3

    International Nuclear Information System (INIS)

    Gruhn, K.; Zander, R.

    1987-01-01

    In two experiments with colostomized broiler hens the influence of a straw meal supplement on the apparent digestibility of the amino acids of the ration and the 15 N-labelled basic amino acids in wheat was studied. In experiment 1 the animals received 120 g mixed feed plus 0, 20, 30 and 40 g straw meal per animal and day. The digestibility of the amino acids decreased on average from 86% to 83%, 80% and 79% with the growing straw intake. In contrast to the control variant, 20 g straw meal intake resulted in a singificant decrease of digestibility for lysine, histidine, glycine, tyrosine, phenylanaline, cystine and methionine. 30 and 40 g straw meal reduced significantly the digestibility of all amino acids with the exception of arginine. The amino acid composition of the crude protein in feces changed only very slightly due to the straw supplement. In experiment 2 15 N-labelled wheat was a component of the ration. Of the 15 N-labelled amino acids lysine, histidine and arginine, 88, 90 and 95% were apparently digested. The adaptation of the animals to straw meal intake did not change the digestibility of the amino acids. (author)

  3. Metabolic Adaptation, a Specialized Leaf Organ Structure and Vascular Responses to Diurnal N2 Fixation by Nostoc azollae Sustain the Astonishing Productivity of Azolla Ferns without Nitrogen Fertilizer.

    Science.gov (United States)

    Brouwer, Paul; Bräutigam, Andrea; Buijs, Valerie A; Tazelaar, Anne O E; van der Werf, Adrie; Schlüter, Urte; Reichart, Gert-Jan; Bolger, Anthony; Usadel, Björn; Weber, Andreas P M; Schluepmann, Henriette

    2017-01-01

    Sustainable agriculture demands reduced input of man-made nitrogen (N) fertilizer, yet N 2 fixation limits the productivity of crops with heterotrophic diazotrophic bacterial symbionts. We investigated floating ferns from the genus Azolla that host phototrophic diazotrophic Nostoc azollae in leaf pockets and belong to the fastest growing plants. Experimental production reported here demonstrated N-fertilizer independent production of nitrogen-rich biomass with an annual yield potential per ha of 1200 kg -1 N fixed and 35 t dry biomass. 15 N 2 fixation peaked at noon, reaching 0.4 mg N g -1 dry weight h -1 . Azolla ferns therefore merit consideration as protein crops in spite of the fact that little is known about the fern's physiology to enable domestication. To gain an understanding of their nitrogen physiology, analyses of fern diel transcript profiles under differing nitrogen fertilizer regimes were combined with microscopic observations. Results established that the ferns adapted to the phototrophic N 2 -fixing symbionts N. azollae by (1) adjusting metabolically to nightly absence of N supply using responses ancestral to ferns and seed plants; (2) developing a specialized xylem-rich vasculature surrounding the leaf-pocket organ; (3) responding to N-supply by controlling transcripts of genes mediating nutrient transport, allocation and vasculature development. Unlike other non-seed plants, the Azolla fern clock is shown to contain both the morning and evening loops; the evening loop is known to control rhythmic gene expression in the vasculature of seed plants and therefore may have evolved along with the vasculature in the ancestor of ferns and seed plants.

  4. Influence of ensiling, exogenous protease addition, and bacterial inoculation on fermentation profile, nitrogen fractions, and ruminal in vitro starch digestibility in rehydrated and high-moisture corn.

    Science.gov (United States)

    Ferraretto, L F; Fredin, S M; Shaver, R D

    2015-10-01

    Exogenous protease addition may be an option to increase proteolysis of zein proteins and thus starch digestibility in rehydrated and high-moisture corn (HMC) ensiled for short periods. In addition, microbial inoculation may accelerate fermentation and increase acid production and thus increase solubilization of zein proteins. Four experiments were performed to evaluate the effect on fermentation profile, N fractions, and ruminal in vitro starch digestibility (ivSD) of the following: (1) rehydration and ensiling of dry ground corn; (2) exogenous protease addition to rehydrated un-ensiled and ensiled corn; (3) exogenous protease addition or inoculation in rehydrated ensiled corn; and (4) exogenous protease addition or inoculation in HMC. Experiments 1, 2, and 3 were performed with 7 treatments: dry ground corn (DGC); DGC rehydrated to a targeted dry matter content of 70% (REH); REH treated with exogenous protease (REH+); REH ensiled for 30 d (ENS); ENS treated with exogenous protease (ENS+); ENS treated with a microbial inoculant containing Lactobacillus plantarum, Lactobacillus casei, Enterococcus faecium, and Pediococcus sp. (ENSI); and ENS treated with exogenous protease and microbial inoculant (ENSI+). Experiment 1 compared DGC, REH, and ENS with ivSD being greater for ENS (64.9%) than DGC and REH (51.7% on average). Experiment 2 compared REH and ENS without or with exogenous protease addition (REH+ and ENS+, respectively). Ensiling and exogenous protease addition increased ivSD, but exogenous protease addition was more effective in ENS than REH (6.4 vs. 2.6 percentage unit increase). Experiment 3 compared the effects of exogenous protease addition and inoculation in ENS corn (ENS, ENS+, ENSI, and ENSI+). The addition of protease, but not inoculant, increased ivSD. Inoculation reduced pH and acetate, propionate, and ethanol concentrations, and increased lactate and total acid concentrations. In experiment 4, 8 treatments were a combination of HMC noninoculated

  5. Effects of nitro-treatment on Salmonella, E. coli and nitrogen metabolism during composting of poultry litter

    Science.gov (United States)

    Poultry litter contains appreciable amounts of uric acid which makes it a good crude protein supplement for ruminants whose gut microbes transform the nitrogen in uric acid into high quality microbial protein. However, poultry litter must be treated to kill bacterial pathogens before feeding. Pres...

  6. Microbial protein synthesis and nitrogen metabolism in cows bred on tropical pasture and fed on cassava root and corn

    Directory of Open Access Journals (Sweden)

    Ádler Carvalho da Silva

    2014-05-01

    Full Text Available Current experiment evaluated the effect of replacement of full corn meal by dehydrated ground cassava roots at levels 0%, 25%, 50%, 75% and 100% in experimental supplements for lactating cows grazing on irrigated and fertilized tropical pastures. Ten Holstein cows were divided into two 5 x 5 Latin squares, with average initial 150 days of lactation, milk production 22±3.30 kg day-1 at the beginning of experiment and initial body weight of 603±65 kg. Cows were maintained on pasture consisting of elephant grass (Pennisetum purpureum, Schum cultivar Pioneiro, intercropped with Tifton 85 (Cynodon nlemfuensis, fertilized with 600 kg nitrogen per hectare year-1. There was no significant difference (p > 0.05 between the substitution levels of corn meal by ground and dehydrated cassava root in the concentrate on the synthesis of microbial protein with an estimated average of 1,288.49 g day-1 and efficiency in the synthesis of microbial protein per kilogram of TDN with estimated average of 91.30 g kg-1 TDN. Nitrogen equilibrium showed an estimated average of 218.79 g day-1 of retained nitrogen. The microbial protein synthesis and nitrogen balance were not affected by treatments.

  7. Only 7% of the variation in feed efficiency in veal calves can be predicted from variation in feeding motivation, digestion, metabolism, immunology, and behavioral traits in early life.

    Science.gov (United States)

    Gilbert, M S; van den Borne, J J G C; van Reenen, C G; Gerrits, W J J

    2017-10-01

    High interindividual variation in growth performance is commonly observed in veal calf production and appears to depend on milk replacer (MR) composition. Our first objective was to examine whether variation in growth performance in healthy veal calves can be predicted from early life characterization of these calves. Our second objective was to determine whether these predictions differ between calves that are fed a high- or low-lactose MR in later life. A total of 180 male Holstein-Friesian calves arrived at the facilities at 17 ± 3.4 d of age, and blood samples were collected before the first feeding. Subsequently, calves were characterized in the following 9 wk (period 1) using targeted challenges related to traits within each of 5 categories: feeding motivation, digestion, postabsorptive metabolism, behavior and stress, and immunology. In period 2 (wk 10-26), 130 calves were equally divided over 2 MR treatments: a control MR that contained lactose as the only carbohydrate source and a low-lactose MR in which 51% of the lactose was isocalorically replaced by glucose, fructose, and glycerol (2:1:2 ratio). Relations between early life characteristics and growth performance in later life were assessed in 117 clinically healthy calves. Average daily gain (ADG) in period 2 tended to be greater for control calves (1,292 ± 111 g/d) than for calves receiving the low-lactose MR (1,267 ± 103 g/d). Observations in period 1 were clustered per category using principal component analysis, and the resulting principal components were used to predict performance in period 2 using multiple regression procedures. Variation in observations in period 1 predicted 17% of variation in ADG in period 2. However, this was mainly related to variation in solid feed refusals. When ADG was adjusted to equal solid feed intake, only 7% of the variation in standardized ADG in period 2, in fact reflecting feed efficiency, could be explained by early life measurements. This indicates that >90

  8. Analysis of carbon and nitrogen co-metabolism in yeast by ultrahigh-resolution mass spectrometry applying 13C- and 15N-labeled substrates simultaneously

    International Nuclear Information System (INIS)

    Blank, Lars M.; Desphande, Rahul R.; Schmid, Andreas; Hayen, Heiko

    2012-01-01

    Alternative metabolic pathways inside a cell can be deduced using stable isotopically labeled substrates. One prerequisite is accurate measurement of the labeling pattern of targeted metabolites. Experiments are generally limited to the use of single-element isotopes, mainly 13 C. Here, we demonstrate the application of direct infusion nanospray, ultrahigh-resolution Fourier transform ion cyclotron resonance-mass spectrometry (FTICR-MS) for metabolic studies using differently labeled elemental isotopes simultaneously - i.e., 13 C and 15 N - in amino acids of a total protein hydrolysate. The optimized strategy for the analysis of metabolism by a hybrid linear ion trap-FTICR-MS comprises the collection of multiple adjacent selected ion monitoring scans. By limiting both the width of the mass range and the number of ions entering the ICR cell with automated gain control, sensitive measurements of isotopologue distribution were possible without compromising mass accuracy and isotope intensity mapping. The required mass-resolving power of more than 60,000 is only achievable on a routine basis by FTICR and Orbitrap mass spectrometers. Evaluation of the method was carried out by comparison of the experimental data to the natural isotope abundances of selected amino acids and by comparison to GC/MS results obtained from a labeling experiment with 13 C-labeled glucose. The developed method was used to shed light on the complexity of the yeast Saccharomyces cerevisiae carbon-nitrogen co-metabolism by administering both 13 C-labeled glucose and 15 N-labeled alanine. The results indicate that not only glutamate but also alanine acts as an amino donor during alanine and valine synthesis. Metabolic studies using FTICR-MS can exploit new possibilities by the use of multiple-labeled elemental isotopes. (orig.)

  9. Effect of cadmium toxicity on nitrogen metabolism in leaves of Solanum nigrum L. as a newly found cadmium hyperaccumulator

    International Nuclear Information System (INIS)

    Wang Lin; Zhou Qixing; Ding Lingling; Sun Yuebing

    2008-01-01

    Hyperaccumulators are ideal plant species used for phytoremediation of soils contaminated by heavy metals. A full understanding of metal tolerance mechanisms of hyperaccumulators will facilitate enhancing their phytoremediation efficiency. However, how Cd affects N metabolism and which role plays the response of N metabolism to Cd toxicity in the tolerance of hyperaccumulators are still unknown. To clarify these questions, this study investigated the effects of various soil Cd levels on the concentrations of N forms and the activity of key enzymes involved in N metabolism in leaves of the Cd hyperaccumulator, Solanum nigrum L. The results showed that its growth and all N metabolism indicators were normal at low Cd exposure (≤12 mg kg -1 ). At 24 mg Cd kg -1 soil, nitrate assimilation indicators (nitrate concentration and activity of nitrate reductase) were reduced significantly, whereas most ammonia assimilation indicators (ammonium concentration and activity of glutamine synthetase) remained normal. However, when exposed to a higher Cd level (48 mg kg -1 ), growth and most N metabolism indicators were reduced significantly. Therefore, N metabolism in leaves of S. nigrum could be tolerant of Cd toxicity to a certain extent (soil Cd concentration ≤12 mg kg -1 ), and this might be involved in the Cd-tolerance of this Cd-hyperaccumulator

  10. Digestive diseases

    Science.gov (United States)

    ... prolapse Esophagus problems, such as stricture (narrowing) and achalasia Liver problems, such as hepatitis B or hepatitis ... has received extra training in the diagnosis and treatment of the digestive disorders. Other health care providers ...

  11. Digested disorder

    Science.gov (United States)

    DeForte, Shelly; Reddy, Krishna D; Uversky, Vladimir N

    2013-01-01

    The current literature on intrinsically disordered proteins is overwhelming. To keep interested readers up to speed with this literature, we continue a “Digested Disorder” project and represent a series of reader’s digest type articles objectively representing the research papers and reviews on intrinsically disordered proteins. The only 2 criteria for inclusion in this digest are the publication date (a paper should be published within the covered time frame) and topic (a paper should be dedicated to any aspect of protein intrinsic disorder). The current digest issue covers papers published during the period of April, May, and June of 2013. The papers are grouped hierarchically by topics they cover, and for each of the included paper a short description is given on its major findings. PMID:28516028

  12. Digested disorder

    Science.gov (United States)

    Reddy, Krishna D; DeForte, Shelly; Uversky, Vladimir N

    2014-01-01

    The current literature on intrinsically disordered proteins grows fast. To keep interested readers up to speed with this literature, we continue a “Digested Disorder” project and represent a new issue of reader’s digest of the research papers and reviews on intrinsically disordered proteins. The only 2 criteria for inclusion in this digest are the publication date (a paper should be published within the covered time frame) and topic (a paper should be dedicated to any aspect of protein intrinsic disorder). The current digest issue covers papers published during the third quarter of 2013; i.e., during the period of June, July, and September of 2013. Similar to previous issues, the papers are grouped hierarchically by topics they cover, and for each of the included paper a short description is given on its major findings. PMID:28232877

  13. Intake and digestibility in cattle under grazing supplemented with nitrogenous compounds during dry season Consumo e digestibilidade em bovinos em pastejo durante o período seco recebendo suplementação com compostos nitrogenados

    Directory of Open Access Journals (Sweden)

    Janderson Florencio Figueiras

    2010-06-01

    Full Text Available The objective of this work was to evaluate the effects of supplementation with nitrogenous compounds on intake and digestibility in cattle under grazing during dry season. It was used five Holstein × Zebu steers with average initial live weight of 236 kg, kept in five Brachiaria decumbens Stapf. paddocks (0.34 ha. The experiment was carried out according to a 5 × 5 Latin square design, with five supplementation levels and five experimental periods. The supplementation levels were the following: 0; 0.35; 0.70; 1.05, and 1.40 g of crude protein/kg live weight. A mixture of urea, ammonium sulfate and albumin (4.5:0.5:1.0, respectively was used as nitrogen supplement. The average crude protein levels in the diet were 7.39; 8.92; 10.98; 12.55; and 13.62%, as dry matter basis, for the respective supplementation levels. Linear-response-plateau relationships were observed between intake estimates and diet crude protein levels. The linear-response-plateau pattern showed that intake was increased up to crude protein levels close to 9%, as dry matter basis. The estimates became unchangeable from this level. The total and ruminal digestibility coefficients of dry matter and neutral detergent fiber, and diet level of total digestible nutrients presented a positive linear pattern according to diet crude protein levels. The rumen ammonia nitrogen concentration was linearly increased by diet crude protein levels. This variable assumed the value of 8.00 mg/dL when the intake estimates reached the maximum values. Supplementation with nitrogen compounds in quantities that raise the crude protein content in the diet to levels close to 9% optimizes the use of low-quality forage by cattle under grazing.Objetivou-se avaliar os efeitos da suplementação com compostos nitrogenados sobre o consumo e a digestibilidade em bovinos em pastejo durante o período seco do ano. Foram utilizados cinco novilhos mestiços Holandês × Zebu, com peso vivo (PV médio inicial de

  14. Elucidation of rice rhizosphere metagenome in relation to methane and nitrogen metabolism under elevated carbon dioxide and temperature using whole genome metagenomic approach.

    Science.gov (United States)

    Bhattacharyya, P; Roy, K S; Das, M; Ray, S; Balachandar, D; Karthikeyan, S; Nayak, A K; Mohapatra, T

    2016-01-15

    Carbon (C) and nitrogen (N) mineralization is one of the key processes of biogeochemical cycling in terrestrial ecosystem in general and rice ecology in particular. Rice rhizosphere is a rich niche of microbial diversity influenced by change in atmospheric temperature and concentration of carbon dioxide (CO2). Structural changes in microbial communities in rhizosphere influence the nutrient cycling. In the present study, the bacterial diversity and population dynamics were studied under ambient CO2 (a-CO2) and elevated CO2+temperature (e-CO2T) in lowland rice rhizosphere using whole genome metagenomic approach. The whole genome metagenomic sequence data of lowland rice exhibited the dominance of bacterial communities including Proteobacteria, Firmicutes, Acidobacteria, Actinobacteria and Planctomycetes. Interestingly, four genera related to methane production namely, Methanobacterium, Methanosphaera, Methanothermus and Methanothermococcus were absent in a-CO2 but noticed under e-CO2T. The acetoclastic pathway was found as the predominant pathway for methanogenesis, whereas, the serine pathway was found as the principal metabolic pathway for CH4 oxidation in lowland rice. The abundances of reads of enzymes in the acetoclastic methanogenesis pathway and serine pathways of methanotrophy were much higher in e-CO2T (328 and 182, respectively) as compared with a-CO2 (118 and 98, respectively). Rice rhizosphere showed higher structural diversities and functional activities in relation to N metabolism involving nitrogen fixation, assimilatory and dissimilatory nitrate reduction and denitrification under e-CO2T than that of a-CO2. Among the three pathways of N metabolism, dissimilarity pathways were predominant in lowland rice rhizosphere and more so under e-CO2T. Consequently, under e-CO2T, CH4 emission, microbial biomass nitrogen (MBN) and dehydrogenase activities were 45%, 20% and 35% higher than a-CO2, respectively. Holistically, a high bacterial diversity and

  15. H. guilliermondii impacts growth kinetics and metabolic activity of S. cerevisiae: the role of initial nitrogen concentration.

    Science.gov (United States)

    Lage, Patrícia; Barbosa, Catarina; Mateus, Beatriz; Vasconcelos, Isabel; Mendes-Faia, Arlete; Mendes-Ferreira, Ana

    2014-02-17

    Non-Saccharomyces yeasts include different species which comprise an ecologically and biochemically diverse group capable of altering fermentation dynamics and wine composition and flavour. In this study, single- and mixed-culture of Hanseniaspora guilliermondii and Saccharomyces cerevisiae were used to ferment natural grape-juice, under two nitrogen regimes. In single-culture the strain H. guilliermondii failed to complete total sugar breakdown even though the nitrogen available has not been a limiting factor of its growth or fermentative activity. In mixed-culture, that strain negatively interfered with the growth and fermentative performance of S. cerevisiae, resulting in lower fermentation rate and longer fermentation length, irrespective of the initial nitrogen concentration. The impact of co-inoculation on the volatile compounds profile was more evident in the wines obtained from DAP-supplemented musts, characterised by increased levels of ethyl and acetate esters, associated with fruity and floral character of wines. Moreover, the levels of fatty acids and sulphur compounds which are responsible for unpleasant odours that depreciate wine sensory quality were significantly lower. Accordingly, data obtained suggests that the strain H. guilliermondii has potential to be used as adjunct of S. cerevisiae in wine industry, although possible interactions with S. cerevisiae still need to be elucidated. Copyright © 2013 Elsevier B.V. All rights reserved.

  16. Unraveling the involvement of ABA in the water deficit-induced modulation of nitrogen metabolism in Medicago truncatula seedlings.

    Science.gov (United States)

    Planchet, Elisabeth; Rannou, Olivier; Ricoult, Claudie; Limami, Anis M

    2011-07-01

    Effects of water deficit and/or abscisic acid (ABA) were investigated on early seedling growth of Medicago truncatula, and on glutamate metabolism under dark conditions. Water deficit (simulated by polyethylene glycol, PEG), ABA and their combination resulted in a reduction in growth rate of the embryo axis, and also in a synergistic increase of free amino acid (AA) content. However, the inhibition of water uptake retention induced by water deficit seemed to occur in an ABA-independent manner. Expression of several genes involved in glutamate metabolism was induced during water deficit, whereas ABA, in combination or not with PEG, repressed them. The only exception came from a gene encoding 1-pyrroline-5-carboxylate synthetase (P5CS) which appeared to be induced in an ABA-dependent manner under water deficit. Our results demonstrate clearly the involvement of an ABA-dependent and an ABA-independent regulatory system, governing growth and glutamate metabolism under water deficit.

  17. Amino acid digestibility of different rye genotypes in caecectomised laying hens.

    Science.gov (United States)

    Zuber, Tobias; Miedaner, Thomas; Rosenfelder, Pia; Rodehutscord, Markus

    2016-12-01

    This study investigated the variability of amino acid (AA) digestibility of rye grains in laying hens. Relationships between AA digestibility and physical properties (thousand seed weight, test weight, falling number, and extract viscoelasticity), chemical composition (proximate nutrients, non-starch polysaccharides, AA, minerals, and inositol phosphates), gross energy concentration, and in vitro solubility of nitrogen (N) of the grains were also examined. Twenty rye genotypes were grown under standardised agronomic and environmental conditions as part of a collaborative research project known as "GrainUp". Each genotype was added to a basal diet at 500 g/kg at the expense of maize starch to produce 20 rye diets. The experimental design comprised four Latin Squares (6 × 6) distributed over two runs, resulting in 12 experimental periods. Caecectomised laying hens (LSL-Classic) were individually kept in metabolism cages. Excreta were collected quantitatively for 4 d, and AA digestibility of the rye genotypes was determined using a regression approach. The digestibility of AA was generally low but varied significantly among the 20 rye genotypes, especially for Lys (digestibility range 35-59%), Met (57-75%), Thr (34-54%), and Trp (36-71%). Nevertheless, physical and chemical characteristics as well as the in vitro solubility of N correlated in only a few cases with AA digestibility. Multiple linear regression was used to calculate equations to predict AA digestibility based on the analysed characteristics. However, their explanatory power, as judged by the adjusted R(2), was not sufficiently precise for practical application (below 0.6 for most AA). In conclusion, the AA digestibility of rye grain is generally low and varies significantly between crop genotypes. Equations based on its physical and chemical characteristics are not sufficiently precise to be useful for feed formulation.

  18. The anaerobic digestion process

    Energy Technology Data Exchange (ETDEWEB)

    Rivard, C.J. [National Renewable Energy Lab., Golden, CO (United States); Boone, D.R. [Oregon Graduate Inst., Portland, OR (United States)

    1996-01-01

    The microbial process of converting organic matter into methane and carbon dioxide is so complex that anaerobic digesters have long been treated as {open_quotes}black boxes.{close_quotes} Research into this process during the past few decades has gradually unraveled this complexity, but many questions remain. The major biochemical reactions for forming methane by methanogens are largely understood, and evolutionary studies indicate that these microbes are as different from bacteria as they are from plants and animals. In anaerobic digesters, methanogens are at the terminus of a metabolic web, in which the reactions of myriads of other microbes produce a very limited range of compounds - mainly acetate, hydrogen, and formate - on which the methanogens grow and from which they form methane. {open_quotes}Interspecies hydrogen-transfer{close_quotes} and {open_quotes}interspecies formate-transfer{close_quotes} are major mechanisms by which methanogens obtain their substrates and by which volatile fatty acids are degraded. Present understanding of these reactions and other complex interactions among the bacteria involved in anaerobic digestion is only now to the point where anaerobic digesters need no longer be treated as black boxes.

  19. Regulators of nonsulfur purple phototrophic bacteria and the interactive control of CO2 assimilation, nitrogen fixation, hydrogen metabolism and energy generation.

    Science.gov (United States)

    Dubbs, James M; Tabita, F Robert

    2004-06-01

    For the metabolically diverse nonsulfur purple phototrophic bacteria, maintaining redox homeostasis requires balancing the activities of energy supplying and energy-utilizing pathways, often in the face of drastic changes in environmental conditions. These organisms, members of the class Alphaproteobacteria, primarily use CO2 as an electron sink to achieve redox homeostasis. After noting the consequences of inactivating the capacity for CO2 reduction through the Calvin-Benson-Bassham (CBB) pathway, it was shown that the molecular control of many additional important biological processes catalyzed by nonsulfur purple bacteria is linked to expression of the CBB genes. Several regulator proteins are involved, with the two component Reg/Prr regulatory system playing a major role in maintaining redox poise in these organisms. Reg/Prr was shown to be a global regulator involved in the coordinate control of a number of metabolic processes including CO2 assimilation, nitrogen fixation, hydrogen metabolism and energy-generation pathways. Accumulating evidence suggests that the Reg/Prr system senses the oxidation/reduction state of the cell by monitoring a signal associated with electron transport. The response regulator RegA/PrrA activates or represses gene expression through direct interaction with target gene promoters where it often works in concert with other regulators that can be either global or specific. For the key CO2 reduction pathway, which clearly triggers whether other redox balancing mechanisms are employed, the ability to activate or inactivate the specific regulator CbbR is of paramount importance. From these studies, it is apparent that a detailed understanding of how diverse regulatory elements integrate and control metabolism will eventually be achieved.

  20. Effects of dehydrated lucerne and soya bean meal on milk production and composition, nutrient digestion, and methane and nitrogen losses in dairy cows receiving two different forages.

    Science.gov (United States)

    Doreau, M; Ferlay, A; Rochette, Y; Martin, C

    2014-03-01

    Dehydrated lucerne is used as a protein source in dairy cow rations, but little is known about the effects of lucerne on greenhouse gas production by animals. Eight Holstein dairy cows (average weight: 582 kg) were used in a replicated 4 × 4 Latin square design. They received diets based on either maize silage (M) or grass silage (G) (45% of diet on dry matter (DM) basis), with either soya bean meal (15% of diet DM) completed with beet pulp (15% of diet DM) (SP) or dehydrated lucerne (L) (30% of diet DM) as protein sources; MSP, ML, GSP and GL diets were calculated to meet energy requirements for milk production by dairy cows and degradable protein for rumen microbes. Dry matter intake (DMI) did not differ among diets (18.0 kg/day DMI); milk production was higher with SP diets than with L diets (26.0 v. 24.1 kg/day), but milk production did not vary with forage type. Milk fatty-acid (FA) composition was modified by both forage and protein sources: L and G diets resulted in less saturated FA, less linoleic acid, more trans-monounsaturated FA, and more linolenic acid than SP and M diets, respectively. Enteric methane (CH4) production, measured by the SF6 tracer method, was higher for G diets than for M diets, but did not differ with protein source. The same effects were observed when CH4 was expressed per kg milk. Minor effects of diets on rumen fermentation pattern were observed. Manure CH4 emissions estimated from faecal organic matter were negatively related to diet digestibility and were thus higher for L than SP diets, and higher for M than G diets; the resulting difference in total CH4 production was small. Owing to diet formulation constraints, N intake was higher for SP than for L diets; interaction between forage type and protein source was significant for N intake. The same statistical effects were found for N in milk. Faecal and urinary N losses were determined from total faeces and urine collection. Faecal N output was lower for M than for G diets but

  1. Methane production, ruminal fermentation characteristics, nutrient digestibility, nitrogen excretion, and milk production of dairy cows fed conventional or brown midrib corn silage.

    Science.gov (United States)

    Hassanat, F; Gervais, R; Benchaar, C

    2017-04-01

    The objective of this study was to examine the effect of replacing conventional corn silage (CCS) with brown midrib corn silage (BMCS) in dairy cow diets on enteric CH 4 emission, nutrient intake, digestibility, ruminal fermentation characteristics, milk production, and N excretion. Sixteen rumen-cannulated lactating cows used in a crossover design (35-d periods) were fed (ad libitum) a total mixed ration (forage:concentrate ratio = 65:35, dry matter basis) based (59% dry matter) on either CCS or BMCS. Dry matter intake and milk yield increased when cows were fed BMCS instead of CCS. Of the milk components, only milk fat content slightly decreased when cows were fed the BMCS-based diet compared with when fed the CCS-based diet (3.81 vs. 3.92%). Compared with CCS, feeding BMCS to cows increased yields of milk protein and milk fat. Ruminal pH, protozoa numbers, total VFA concentration, and molar proportions of acetate and propionate were similar between cows fed BMCS and those fed CCS. Daily enteric CH 4 emission (g/d) was unaffected by dietary treatments, but CH 4 production expressed as a proportion of gross energy intake or on milk yield basis was lower for cows fed the BMCS-based diet than for cows fed the CCS-based diet. A decline in manure N excretion and a shift in N excretion from urine to feces were observed when BMCS replaced CCS in the diet, suggesting reduced potential of manure N volatilization. Results from this study show that improving fiber quality of corn silage in dairy cow diets through using brown midrib trait cultivar can reduce enteric CH 4 emissions as well as potential emissions of NH 3 and N 2 O from manure. However, CH 4 emissions during manure storage may increase due to excretion of degradable OM when BMCS diet is fed, which merits further investigation. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  2. Investigation of carbohydrate and protein metabolism in the digestive organs of the rabbit under the combined influence of vibration, acceleration and irradiation

    Science.gov (United States)

    Yuy, R. I.

    1975-01-01

    During spaceflight, the organism is subjected to the influence of various extremal factors such as acceleration, vibration, irradiation, etc. The study of the influence of these factors on metabolism, especially carbohydrate and protein metabolism, in young rabbits is of great significance in simulation experiments. Dynamic factors and irradiation, depending on dose and duration, lead to reduced RNA and protein metabolism.

  3. Urea and short-chain fatty acids metabolism in Holstein cows fed a low-nitrogen grass-based diet

    DEFF Research Database (Denmark)

    Røjen, B A; Lund, P; Kristensen, N B

    2008-01-01

    Three ruminally cannulated and multicatheterised lactating dairy cows were used to investigate the effect of different supplement strategies to fresh clover grass on urea and short-chain fatty acid (SCFA) metabolism in a zero-grazing experiment with 24-h blood and ruminal samplings....

  4. Effects of acute changes in salinity and temperature on routine metabolism and nitrogen excretion in gambusia (Gambusia affinis) and zebrafish (Danio rerio).

    Science.gov (United States)

    Uliano, E; Cataldi, M; Carella, F; Migliaccio, O; Iaccarino, D; Agnisola, C

    2010-11-01

    Acute stress may affect metabolism and nitrogen excretion as part of the adaptive response that allows animals to face adverse environmental changes. In the present paper the acute effects of different salinities and temperatures on routine metabolism, spontaneous activity and excretion of ammonia and urea were studied in two freshwater fish: gambusia, Gambusia affinis and zebrafish, Danio rerio, acclimated to 27 degrees C. The effects on gill morphology were also evaluated. Five salinities (0 per thousand, 10 per thousand, 20 per thousand, 30 per thousand and 35 per thousand) were tested in gambusia, while four salinities were used in zebrafish (0 per thousand, 10 per thousand, 20 per thousand and 25 per thousand). Each salinity acute stress was tested alone or in combination with an acute temperature reduction to 20 degrees C. In gambusia, both salinity and temperature acute stress strongly stimulated urea excretion. Routine oxygen consumption was barely affected by acute salinity or temperature stress, and was reduced by the combined effects of temperature and high salinity. Gills maintained their structural integrity in all stressing conditions; hyperplasia and hypertrophy of mitochondria-rich cells were observed. In zebrafish, temperature and salinity acute changes, both alone and in combination, scarcely affected any parameter tested. The major effect observed was a reduction of nitrogen excretion at 20 degrees C-25 per thousand; under these extreme conditions a significant structural disruption of gills was observed. These results confirm the high tolerance to acute salinity and temperature stress in gambusia, and demonstrate the involvement of urea excretion modulation in the stress response in this species. Copyright 2010 Elsevier Inc. All rights reserved.

  5. [Effects of different NO3--N/NH4+-N ratios on cucumber seedlings growth, nitrogen absorption and metabolism under suboptimal temperature and light intensity].

    Science.gov (United States)

    Zhang, Xiao Cui; Liu, Yu Mei; Bai, Long Qiang; He, Chao Xing; Yu, Xian Chang; Li, Yan Su

    2016-08-01

    Cucumber (cv. Zhongnong 26) was used as material, the effects of NO 3 - -N/NH 4 + -N ratios on growth and physiological characteristics of cucumber seedlings under suboptimal temperature and light intensity (18 ℃/10 ℃,180 ± 20 μmol·m -2 ·s -1 ) were studied. Total nitrogen in the nutrient solution was equal and three NO 3 - -N/NH 4 + -N ratios, 26:2, 21:7 and 14:14, were applied as treatments. The results showed that cucumber treated by NO 3 - -N/NH 4 + -N=21:7 had the longest total root length, the biggest root volume and root surface area, and the maximum number of root tips. H + -ATPase activity and relative expression of genes encoding nitrate transporter (NRT) and ammonium transporter (AMT) in cucumber roots were increased significantly by the treatment of NO 3 - -N/NH 4 + -N=21:7. In addition, nitrate reductase (NR), glutamine synthetase (GS) and glutamate synthase (GOGAT) in cucumber leaves under the treatment of NO 3 - -N/NH 4 + -N=21:7 were higher. As a result, the nitrogen content and biomass of cucumber were significantly increased. Compared with the plants under the treatment of NO 3 - -N/NH 4 + -N=26:2 or 14:14, cucumber seedlings under the treatment of NO 3 - -N/NH 4 + -N=21:7 had the highest biomass and total dry mass (DM) which were increased by 14.0% and 19.3% respectively under suboptimal temperature and light intensity. In conclusion, under suboptimal environmental conditions, NO 3 - -N/NH 4 + -N ratio could be adjusted to increase nitrogen absorption and metabolism of cucumber and alleviate the de-trimental effects caused by suboptimal conditions and promoted the cucumber growth.

  6. Transcriptome Analysis of Two Rice Varieties Contrasting for Nitrogen Use Efficiency under Chronic N Starvation Reveals Differences in Chloroplast and Starch Metabolism-Related Genes

    Directory of Open Access Journals (Sweden)

    Subodh Kumar Sinha

    2018-04-01

    Full Text Available The nitrogen use efficiency (NUE of crop plants is limited and enhancing it in rice, a major cereal crop, would be beneficial for farmers and the environment alike. Here we report the genome-wide transcriptome analysis of two rice genotypes, IR 64 (IR64 and Nagina 22 (N22 under optimal (+N and chronic starvation (-N of nitrogen (N from 15-day-old root and shoot tissues. The two genotypes were found to be contrasting in their response to -N; IR64 root architecture and root dry weight remained almost equivalent to that under +N conditions, while N22 showed high foraging ability but a substantial reduction in biomass under -N. Similarly, the photosynthetic pigments showed a drastic reduction in N22 under low N, while IR64 was more resilient. Nitrate reductase showed significantly low specific activity under -N in both genotypes. Glutamate synthase (GOGAT and citrate synthase CS activity were highly reduced in N22 but not in IR64. Transcriptome analysis of these genotypes revealed nearly double the number of genes to be differentially expressed (DEGs in roots (1016 compared to shoots (571. The response of the two genotypes to N starvation was distinctly different reflecting their morphological/biochemical response with just two and eight common DEGs in the root and shoot tissues. There were a total of 385 nitrogen-responsive DEGs (106 in shoots and 279 in roots between the two genotypes. Fifty-two of the 89 DEGs identified as specific to N22 root tissues were also found to be differentially expressed between the two genotypes under -N. Most of these DEGs belonged to starch and chloroplast metabolism, followed by membrane and signaling proteins. Physical mapping of DEGs revealed 95 DEGs in roots and 76 in shoots to be present in quantitative trait loci (QTL known for NUE.

  7. Metabolic engineering of the regulators in nitrogen catabolite repression to reduce the production of ethyl carbamate in a model rice wine system.

    Science.gov (United States)

    Zhao, Xinrui; Zou, Huijun; Fu, Jianwei; Zhou, Jingwen; Du, Guocheng; Chen, Jian

    2014-01-01

    Rice wine has been one of the most popular traditional alcoholic drinks in China. However, the presence of potentially carcinogenic ethyl carbamate (EC) in rice wine has raised a series of food safety issues. During rice wine production, the key reason for EC formation is urea accumulation, which occurs because of nitrogen catabolite repression (NCR) in Saccharomyces cerevisiae. NCR represses urea utilization by retaining Gln3p in the cytoplasm when preferred nitrogen sources are present. In order to increase the nuclear localization of Gln3p, some possible phosphorylation sites on the nuclear localization signal were mutated and the nuclear localization regulation signal was truncated, and the disruption of URE2 provided an additional method of reducing urea accumulation. By combining these strategies, the genes involved in urea utilization (DUR1,2 and DUR3) could be significantly activated in the presence of glutamine. During shake flask fermentations of the genetically modified strains, very little urea accumulated in the medium. Furthermore, the concentrations of urea and EC were reduced by 63% and 72%, respectively, in a model rice wine system. Examination of the normal nutrients in rice wine indicated that there were few differences in fermentation characteristics between the wild-type strain and the genetically modified strain. These results show that metabolic engineering of the NCR regulators has great potential as a method for eliminating EC during rice wine production.

  8. Metabolic Engineering of the Regulators in Nitrogen Catabolite Repression To Reduce the Production of Ethyl Carbamate in a Model Rice Wine System

    Science.gov (United States)

    Zhao, Xinrui; Zou, Huijun; Fu, Jianwei; Chen, Jian

    2014-01-01

    Rice wine has been one of the most popular traditional alcoholic drinks in China. However, the presence of potentially carcinogenic ethyl carbamate (EC) in rice wine has raised a series of food safety issues. During rice wine production, the key reason for EC formation is urea accumulation, which occurs because of nitrogen catabolite repression (NCR) in Saccharomyces cerevisiae. NCR represses urea utilization by retaining Gln3p in the cytoplasm when preferred nitrogen sources are present. In order to increase the nuclear localization of Gln3p, some possible phosphorylation sites on the nuclear localization signal were mutated and the nuclear localization regulation signal was truncated, and the disruption of URE2 provided an additional method of reducing urea accumulation. By combining these strategies, the genes involved in urea utilization (DUR1,2 and DUR3) could be significantly activated in the presence of glutamine. During shake flask fermentations of the genetically modified strains, very little urea accumulated in the medium. Furthermore, the concentrations of urea and EC were reduced by 63% and 72%, respectively, in a model rice wine system. Examination of the normal nutrients in rice wine indicated that there were few differences in fermentation characteristics between the wild-type strain and the genetically modified strain. These results show that metabolic engineering of the NCR regulators has great potential as a method for eliminating EC during rice wine production. PMID:24185848

  9. Roles of magnetite and granular activated carbon in improvement of anaerobic sludge digestion.

    Science.gov (United States)

    Peng, Hong; Zhang, Yaobin; Tan, Dongmei; Zhao, Zhiqiang; Zhao, Huimin; Quan, Xie

    2018-02-01

    Granular activated carbon (GAC) or magnetite could promote methane production from organic wastes, but their roles in enhancing anaerobic sludge digestion have not been clarified. GAC, magnetite and their combination were complemented into sludge digesters, respectively. Experimental results showed that average methane production increased by 7.3% for magnetite, 13.1% for GAC, and 20% for the combination of magnetite and GAC, and the effluent TCOD of the control, magnetite, GAC and magnetite-GAC digesters on day 56 were 53.2, 49.6, 48.0 and 46.6 g/L, respectively. Scanning electron microscope (SEM), nitrogen adsorption, Fourier transform infrared spectroscopy (FTIR) and microbial analysis indicated that magnetite enriched iron-reducing bacteria responsible for sludge hydrolysis while GAC enhanced syntrophic metabolism between iron-reducing bacteria and methanogens due to its high electrical conductivity and large surface area. Supplementing magnetite and GAC together into an anaerobic digester simultaneously accelerated sludge hydrolysis and methane production, resulting in better sludge digestion performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Effects of nitrogen infiltration into plant tissue on the metabolism of carbon, with special reference to Themeda triandra Forssk

    Energy Technology Data Exchange (ETDEWEB)

    Amory, A M

    1983-01-01

    The infiltration of nitrate and ammonia into Themeda triandra and Zea mays leaf tissue influenced the carbon dioxide gas exchange characteristics: 1) the carbon dioxide compensation point increased, 2) the net photosynthetic rate was increased by the nitrate ion and decreased by the ammonium ion, and 3) dark respiration was unaffected. /sup 14/CO/sub 2/ assimilation and the partitioning of /sup 14/C by Themeda triandra leaves were influenced by the infiltration of both forms of nitrogen; the amino acid fraction changed in both composition and concentration. Nitrogen infiltration increased the activities of the following enzymes: aspartate amino-transferase, PEP carboxylase and RuBP carboxylase. Methionine sulphoximine (inhibitor of glutamate synthetase) increased the carbon dioxide compensation point and formate pool size. Infiltration of nitrate and ammonia enhanced the /sup 14/C uptake from labelled glycolate, glyoxylate and formate into the water soluble fraction of Themeda triandra leaves. The activities of RuBP carboxylase and RuBP oxygenase (to a greater extent) were increased by the addition of nitrate and ammonia in vitro.

  11. Nitrogen utilization, preweaning nutrient digestibility, and growth effects of Holstein dairy calves fed 2 amounts of a moderately high protein or conventional milk replacer.

    Science.gov (United States)

    Chapman, C E; Hill, T M; Elder, D R; Erickson, P S

    2017-01-01

    Studies have shown that calves fed milk replacers (MR) with crude protein (CP) concentrations greater than 20%, as typically found in conventional MR, have higher dry matter intakes (DMI) and greater average daily gains (ADG) but consume less starter, which can lead to stress during weaning and reduced rumen development. The greater amount of CP being fed to preweaned calves may alter their nitrogen (N) balance, and excess N may be excreted in the urine. The objective of this study was to determine N utilization in preweaned calves fed diets varying in the amount of CP and MR fed. This study used 24 newborn dairy heifer calves blocked by birth and randomly assigned to 1 of 3 treatments: (1) 446g dry matter (DM) of a conventional MR (CON; 20% CP, 20% fat), (2) 669g DM of a moderately high protein MR (moderate; MOD; 26% CP, 18% fat), or (3) 892g DM of a moderately high protein MR (aggressive; AGG; 26% CP, 18% fat). All calves had ad libitum access to starter and water. Both MR and starter were medicated with decoquinate. During weaning (d 43-49), the morning MR feeding ceased. On d 50, all MR feedings ended; however, starter and water intakes were continuously recorded until d 56. At 5wk of age, urine was collected using urinary catheters for 3d and chromium oxide was administered by bolus at 2g/d for 7d to estimate N efficiency. Calves fed MOD and AGG had similar starter intakes, feed efficiencies, and ADG, with the combined treatments having reduced starter intakes (258 vs. 537g/d), greater ADG (674 vs. 422g/d), and improved feed efficiency (0.57 vs. 0.45 gain:feed) compared with CON calves preweaning. However, DMI and water intake were similar across all treatments. Results from the N utilization phase showed that MOD and AGG treatments had similar but lower N efficiency compared with CON calves (45.5 vs. 52.7%). This could be due to MOD- and AGG-fed calves having greater urine volume and thereby, greater combined urine N output compared with CON calves (17.6 vs

  12. Digestive tract

    International Nuclear Information System (INIS)

    Rocha, A.F.G. da

    1976-01-01

    Scintiscanning of salivary glands with (sup 99m)Tc is commented. The uses of triolein - and oleic acid labelled with 131 I, 125 I or 82 Br are discussed in the study of fat absorption, as well as 14 C and 191 Y. The use of 57 Co as a radiotracer in the intestinal absorption of vitamin B 12 is analysed. Orientation is given about 51 Cr - albumin clearance in the study of plasmatic protein loss by digestive tract. The radiotracers 131 I, 125 I and 51 Cr are pointed out in the investigation of immunoglobulins. Consideration is given to the quantification of digestive bleedings by the use of 51 Cr [pt

  13. Fluctuation of Dof1/Dof2 expression ratio under the influence of varying nitrogen and light conditions: involvement in differential regulation of nitrogen metabolism in two genotypes of finger millet (Eleusine coracana L.).

    Science.gov (United States)

    Gupta, Supriya; Gupta, Sanjay Mohan; Gupta, Alok Kumar; Gaur, Vikram Singh; Kumar, Anil

    2014-08-10

    In order to gain insights into the mechanism of high nitrogen use efficiency (NUE) of finger millet (FM) the role of Dof2 transcription factor (TF), which is a repressor of genes involved in C/N metabolism was investigated. The partial cDNA fragment of EcDof2 (912-bp; GenBank acc. no. KF261117) was isolated and characterized from finger millet (FM) that showed 63% and 58% homology with Dof2 of Zea mays at nucleotide and protein level, respectively. Its expression studies were carried out along with the activator EcDof1 in two genotypes (GE3885, high protein genotype (HPG); GE1437, low protein genotype (LPG)) of FM differing in grain protein contents (13.8% and 6.2%) showed that EcDof2 is expressed in both shoot and root tissues with significantly (p≤0.05) higher expression in the roots. The diurnal expression of both EcDof1 and EcDof2 in shoots was differential having different time of peak expression indicating a differential response to diurnal condition. Under continuous dark conditions, expression of EcDof1 and EcDof2 oscillated in both the genotypes whereas on illumination, the fold expression of EcDof1 was higher as compared to EcDof2. Under increasing nitrate concentration, EcDof2 expression increases in roots and shoots of LPG while it remains unchanged in HPG. However, the EcDof1 expression was found to increase in both genotypes. Further, time kinetics studies under single nitrate concentration revealed that EcDof2 was repressed in the roots of both genotypes whereas EcDof1 oscillated with time. The EcDof1/EcDof2 ratio measured showed differential response under different light and nitrogen conditions. It was higher in the roots of HPG indicating higher activation of genes involved in N uptake and assimilation resulting in high grain protein accumulation. The results indicate that both light and nitrogen concentration influence Dof1 and Dof2 expression and suggests a complex pattern of regulation of genes influenced by these plant specific TFs. In

  14. Spatial and temporal regulation of the metabolism of reactive oxygen and nitrogen species during the early development of pepper (Capsicum annuum) seedlings.

    Science.gov (United States)

    Airaki, Morad; Leterrier, Marina; Valderrama, Raquel; Chaki, Mounira; Begara-Morales, Juan C; Barroso, Juan B; del Río, Luis A; Palma, José M; Corpas, Francisco J

    2015-09-01

    The development of seedlings involves many morphological, physiological and biochemical processes, which are controlled by many factors. Some reactive oxygen and nitrogen species (ROS and RNS, respectively) are implicated as signal molecules in physiological and phytopathological processes. Pepper (Capsicum annuum) is a very important crop and the goal of this work was to provide a framework of the behaviour of the key elements in the metabolism of ROS and RNS in the main organs of pepper during its development. The main seedling organs (roots, hypocotyls and green cotyledons) of pepper seedlings were analysed 7, 10 and 14 d after germination. Activity and gene expression of the main enzymatic antioxidants (catalase, ascorbate-glutathione cycle enzymes), NADP-generating dehydrogenases and S-nitrosoglutathione reductase were determined. Cellular distribution of nitric oxide ((·)NO), superoxide radical (O2 (·-)) and peroxynitrite (ONOO(-)) was investigated using confocal laser scanning microscopy. The metabolism of ROS and RNS during pepper seedling development was highly regulated and showed significant plasticity, which was co-ordinated among the main seedling organs, resulting in correct development. Catalase showed higher activity in the aerial parts of the seedling (hypocotyls and green cotyledons) whereas roots of 7-d-old seedlings contained higher activity of the enzymatic components of the ascorbate glutathione cycle, NADP-isocitrate dehydrogenase and NADP-malic enzyme. There is differential regulation of the metabolism of ROS, nitric oxide and NADP dehydrogenases in the different plant organs during seedling development in pepper in the absence of stress. The metabolism of ROS and RNS seems to contribute significantly to plant development since their components are involved directly or indirectly in many metabolic pathways. Thus, specific molecules such as H2O2 and NO have implications for signalling, and their temporal and spatial regulation contributes

  15. Integrated operation of the photorespiratory cycle and cytosolic metabolism in the modulation of primary nitrogen assimilation and export of organic N-transport compounds from leaves: a hypothesis.

    Science.gov (United States)

    Misra, Jitendra B

    2014-02-15

    Photorespiration is generally considered to be an essentially dissipative process, although it performs some protective and essential functions. A theoretical appraisal indicates that the loss of freshly assimilated CO2 due to photorespiration in well-watered plants may not be as high as generally believed. Even under moderately adverse conditions, these losses may not exceed 10%. The photorespiratory metabolism of the source leaves of well-watered and well-nourished crop plants ought to be different from that of other leaves because the fluxes of the export of both carbohydrates and organic N-transport compounds in source leaves is quite high. With a heuristic approach that involved the dovetailing of certain metabolic steps with the photorespiratory cycle (PR-cycle), a novel network is proposed to operate in the source-leaves of well-watered and well-nourished plants. This network allows for the diversion of metabolites from their cyclic-routes in sizeable quantities. With the removal of considerable quantities of glycine and serine from the cyclic route, the number of RuBP oxygenation events would be several times those of the formation of hydroxypyruvate. Thus, to an extreme extent, photorespiratory metabolism would become open-ended and involve much less futile recycling of glycine and serine. Conversion of glyoxylate to glycine has been proposed to be a crucial step in the determination of the relative rates of the futile (cyclic) and anabolic (open-ended) routes. Thus, in the source leaves of well-watered and well-nourished plants, the importance of the cyclic route is limited to the salvaging of photorespiratory intermediates for the regeneration of RuBP. The proposed network is resilient enough to coordinate the rates of the assimilation of carbon and nitrogen in accordance with the moisture and N-fertility statuses of the soil. Copyright © 2013 Elsevier GmbH. All rights reserved.

  16. Effects of replacing soybean meal with canola meal or treated canola meal on nitrogen metabolism and total tract digestibility in lactating dairy cows

    Science.gov (United States)

    Dietary canola meal (CM) has been shown to improve N efficiency in dairy cows when compared with soybean meal (SBM). Treating CM may increase amino acid (AA) supply from the rumen undegradable protein fraction and improve absorbable AA in the metabolizable protein. The objective of this study was to...

  17. Whole-body nitrogen and tyrosine metabolism in surgical patients receiving branched-chain amino acid solutions

    International Nuclear Information System (INIS)

    Desai, S.P.; Bistrian, B.R.; Moldawer, L.L.; Blackburn, G.L.

    1985-01-01

    Fifteen patients undergoing gastric bypass surgery for morbid obesity received preoperatively a standard crystalline amino acid solution containing 15.6% branched-chain amino acids. During the first five postoperative days, the patients were randomized to receive one of three amino acid solutions of different branched-chain amino acid content. Whole-body amino acid appearance and oxidation were estimated using a continuous intravenous infusion of L-(U- 14 C)-tyrosine preoperatively and on the third postoperative day. This study suggests that an adequate nitrogen intake of a balanced amino acid mixture, as well as a solution enriched with branched-chain amino acids, maintains protein homeostasis and supports protein synthesis similarly in well-nourished patients following major abdominal surgery. A diet containing only branched-chain amino acids in isomolar ratios was as effective at maintaining protein retention and whole-body protein synthesis and albumin renewal postoperatively when compared with a standard amino acid formula

  18. Nitrogen availability for nitrogen fixing cyanobacteria upon growth ...

    African Journals Online (AJOL)

    The filamentous cyanobacterium Nostoc PCC 7120 is able to convert dinitrogen to ammonia in the absence of combined nitrogen. The expression of 20% of coding sequences from all major metabolic categories was examined in nitrogen fixing and non-nitrogen fixing growth conditions. The expression data were correlated ...

  19. Production of methane from kallar grass grown on saline sodic lands: metabolism of carbohydrates, methylated amines and methane precursors during digestion of kallar grass

    International Nuclear Information System (INIS)

    Tabassum, R.; Rajoka, M.I.; Malik, K.A.

    1991-01-01

    Mesophilic anaerobic digestion of kallar grass on saline sodic land was carried out in batch culture at laboratory scale with enriched culture from biogas plant. Analysis were made to determine biogas volume, gas composition and distribution of volatile fatty acids. The fermentation of kallar grass treated with 2% NaOH showed an increase in digestibility from 20-50% and the conversion efficiency approached 80-95% of theoretical yield which was fold higher than the one obtained from untreated substrates. The contents of methane in bio gas was markedly low during the first day of digestion but increased from 75 to 91% at the end of 20 days retention time. Low pH values (6.2) showed the accumulation of acetic butyric and propionic acids. Addition of carbohydrates, methylated amines and other methane precursors were found to stimulate methanogensis at low concentration (0.1%) carbohydrates, (1mM) methylated amines and methane precursors as compared to their higher concentrations. The phase contrast and fluorescence microscopic examinations showed the diverse microbial population of digestor contents. (author)

  20. Growth, photosynthesis and nitrogen metabolism in soybean varieties after exclusion of the UV-B and UV-A/B components of solar radiation

    Directory of Open Access Journals (Sweden)

    Sanjay Singh Baroniya

    2014-12-01

    Full Text Available A field experiment was conducted to study the impact of the exclusion of the solar UV components on growth, photosynthesis and nitrogen metabolism in soybean (Glycine max varieties PK-472, Pusa-24, JS 71-05, JS-335, NRC-7 and Kalitur. The plants were grown in specially designed UV exclusion chambers wrapped with filters to exclude UV-B or UV-A/B and transmitted all UV. Exclusion of UV significantly enhanced the growth of the aerial parts as well as the growth of the below ground parts in all of the six soybean varieties. Nitrate reductase activity (NRA was significantly reduced, whereas leghemoglobin (Lb content, total soluble protein, net photosynthesis (Pn and α-tocopherol content were enhanced after UV exclusion. The exclusion of solar UV-A/B enhanced all parameters to a larger extent than the exclusion of solar UV-B in four of the six varieties of soybean except for NRC-7 and Kalitur. These two varieties responded more to UV-B exclusion compared to UV-A/B exclusion. A significant inverse correlation between the NRA and the number of nodules per plant was observed. The extent of response in all parameters was greater in PK-472 and JS71-05 than that in Kalitur and JS-335 after UV exclusion. The exclusion of UV augmented the growth of nodules, Lb content and α-tocopherol levels and conferred higher rates of Pn to support better growth of nodules. Control plants (+ UV-A/B seemed to fulfill their N demand through the assimilation of NO3− resulting in lower symbiotic nitrogen fixation and higher NR activity.

  1. Nitrogen Metabolism and Growth Enhancement in Tomato Plants Challenged with Trichoderma harzianum Expressing the Aspergillus nidulans Acetamidase amdS Gene

    Science.gov (United States)

    Domínguez, Sara; Rubio, M. Belén; Cardoza, Rosa E.; Gutiérrez, Santiago; Nicolás, Carlos; Bettiol, Wagner; Hermosa, Rosa; Monte, Enrique

    2016-01-01

    Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake. The amdS gene, encoding an acetamidase of Aspergillus, has been used as a selectable marker for the transformation of filamentous fungi, including Trichoderma spp., but the physiological effects of the introduction of this gene into the genome of these microorganisms still remains unexplored. No evidence of amdS orthologous genes has been detected within the Trichoderma spp. genomes and the amdS heterologous expression in Trichoderma harzianum T34 did not affect the growth of this fungus in media lacking acetamide. However, it did confer the ability for the fungus to use this amide as a nitrogen source. Although a similar antagonistic behavior was observed for T34 and amdS transformants in dual cultures against Rhizoctonia solani, Botrytis cinerea, and Fusarium oxysporum, a significantly higher antifungal activity was detected in amdS transformants against F. oxysporum, compared to that of T34, in membrane assays on media lacking acetamide. In Trichoderma-tomato interaction assays, amdS transformants were able to promote plant growth to a greater extent than the wild-type T34, although compared with this strain the transformants showed similar capability to colonize tomato roots. Gene expression patterns from aerial parts of 3-week-old tomato plants treated with T34 and the amdS transformants have also been investigated using GeneChip Tomato Genome Arrays. The downregulation of defense genes and the upregulation of carbon and nitrogen metabolism genes observed in the microarrays were accompanied by (i) enhanced growth, (ii) increased carbon and nitrogen levels, and (iii) a

  2. Nitrogen metabolism and growth enhancement in tomato plants challenged with Trichoderma harzianum expressing the Aspergillus nidulans acetamidase amdS gene

    Directory of Open Access Journals (Sweden)

    Sara Domínguez

    2016-08-01

    Full Text Available Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake. The amdS gene, encoding an acetamidase of Aspergillus, has been used as a selectable marker for the transformation of filamentous fungi, including Trichoderma spp., but the physiological effects of the introduction of this gene into the genome of these microorganisms still remains unexplored. No evidence of amdS orthologous genes has been detected within the Trichoderma spp. genomes and the amdS heterologous expression in T. harzianum T34 did not affect the growth of this fungus in media lacking acetamide. However, it did confer the ability for the fungus to use this amide as a nitrogen source. Although a similar antagonistic behavior was observed for T34 and amdS transformants in dual cultures against Rhizoctonia solani, Botrytis cinerea and Fusarium oxysporum, a significantly higher antifungal activity was detected in amdS transformants against F. oxysporum, compared to that of T34, in membrane assays on media lacking acetamide. In Trichoderma-tomato interaction assays, amdS transformants were able to promote plant growth to a greater extent than the wild-type T34, although compared with this strain the transformants showed similar capability to colonize tomato roots. Gene expression patterns from aerial parts of 3-week-old tomato plants treated with T34 and the amdS transformants have also been investigated using GeneChip Tomato Genome Arrays. The downregulation of defense genes and the upregulation of carbon and nitrogen metabolism genes observed in the microarrays were accompanied by i enhanced growth, ii increased carbon and nitrogen levels and iii a

  3. Nitrogen Metabolism and Growth Enhancement in Tomato Plants Challenged with Trichoderma harzianum Expressing the Aspergillus nidulans Acetamidase amdS Gene.

    Science.gov (United States)

    Domínguez, Sara; Rubio, M Belén; Cardoza, Rosa E; Gutiérrez, Santiago; Nicolás, Carlos; Bettiol, Wagner; Hermosa, Rosa; Monte, Enrique

    2016-01-01

    Trichoderma is a fungal genus that includes species that are currently being used as biological control agents and/or as biofertilizers. In addition to the direct application of Trichoderma spp. as biocontrol agents in plant protection, recent studies have focused on the beneficial responses exerted on plants, stimulating the growth, activating the defenses, and/or improving nutrient uptake. The amdS gene, encoding an acetamidase of Aspergillus, has been used as a selectable marker for the transformation of filamentous fungi, including Trichoderma spp., but the physiological effects of the introduction of this gene into the genome of these microorganisms still remains unexplored. No evidence of amdS orthologous genes has been detected within the Trichoderma spp. genomes and the amdS heterologous expression in Trichoderma harzianum T34 did not affect the growth of this fungus in media lacking acetamide. However, it did confer the ability for the fungus to use this amide as a nitrogen source. Although a similar antagonistic behavior was observed for T34 and amdS transformants in dual cultures against Rhizoctonia solani, Botrytis cinerea, and Fusarium oxysporum, a significantly higher antifungal activity was detected in amdS transformants against F. oxysporum, compared to that of T34, in membrane assays on media lacking acetamide. In Trichoderma-tomato interaction assays, amdS transformants were able to promote plant growth to a greater extent than the wild-type T34, although compared with this strain the transformants showed similar capability to colonize tomato roots. Gene expression patterns from aerial parts of 3-week-old tomato plants treated with T34 and the amdS transformants have also been investigated using GeneChip Tomato Genome Arrays. The downregulation of defense genes and the upregulation of carbon and nitrogen metabolism genes observed in the microarrays were accompanied by (i) enhanced growth, (ii) increased carbon and nitrogen levels, and (iii) a

  4. Carbon-Water-Nitrogen relationships between lichens and the atmosphere: Tools to understand metabolism and ecosystem change

    Directory of Open Access Journals (Sweden)

    Cristina Máguas

    2013-04-01

    Full Text Available Due to the close linking between the biosphere and atmosphere, there are clear impacts of changes in climate, atmospheric deposition of nutrients/pollutants and land use (Global Changes on the terrestrial biosphere. Lichens, with a direct dependence on atmospheric conditions, are much more affected by their immediate microclimate than by the ecosystem’s prevailing macroclimate. In contrast to higher plants, poikilohydric organisms have different mechanisms of water and CO2 exchange. The application of stable isotopes to the understanding of the mechanisms that are fundamental to lichen gas exchange and water uptake is a promising tool for the evaluation of lichen response to environmental changes. Indeed, lichens have been shown to be influenced by a large number of natural and anthropogenic environmental factors, serving as ecological indicators. Thus, we may use these organisms to model the impact of key global change drivers, such as nitrogen deposition and biodiversity changes, at local scale. Particularly useful is the application of the Lichen Diversity Value (LDV in order to evaluate the impact of global drivers. Moreover, it has been shown that these indices, associated with main photobiont types, green-algae (LDVch or cyanobacteria (LDVcyh, and/or nitrophilous versus oligotrophic species, were good candidates as ecological indicators. Besides mapping with high spatial resolution the effects of climate alterations, lichen functional groups could also be used as an early-warning system in order to detect the first effects of climate change in ecosystems before sudden shifts occur on other components that may be less sensitive. Clearly, lichens possess the adequate traits to be used as powerful indicators of complex interactions between atmosphere and biosphere, and thus can generate potentially interesting models for global change drivers.

  5. Elementary budget of stag beetle larvae associated with selective utilization of nitrogen in decaying wood.

    Science.gov (United States)

    Tanahashi, Masahiko; Ikeda, Hiroshi; Kubota, Kôhei

    2018-05-03

    Wood degradation by insects plays important roles for the forest matter cycling. Since wood is deficient in nitrogen compared to the insect body, wood-feeding insects need to assimilate the nitrogen selectively and discard an excess carbon. Such a stoichiometric imbalance between food and body will cause high metabolic cost; therefore, wood-feeding insects may somehow alleviate the stoichiometric imbalance. Here, we investigated the carbon and nitrogen budgets of the larvae of stag beetle, Dorcus rectus, which feed on decaying wood. Assimilation efficiency of ingested wood was 22%, and those values based on the carbon and nitrogen were 27 and 45%, respectively, suggesting the selective digestion of nitrogen in wood. Element-based gross growth efficiency was much higher for nitrogen (45%) than for carbon (3%). As a result, the larvae released 24% of the ingested carbon as volatile, whereas almost no gaseous exchange was observed for nitrogen. Moreover, solubility-based elementary analysis revealed that the larvae mainly utilized alkaline-soluble-water-insoluble fraction of wood, which is rich in nitrogen. Actually, the midgut of the larvae was highly alkaline (pH 10.3). Stag beetle larvae are known to exhibit coprophagy, and here we also confirmed that alkaline-soluble-water-insoluble nitrogen increased again from fresh feces to old feces in the field. Stable isotope analysis suggested the utilization of aerial nitrogen by larvae; however, its actual contribution is still disputable. Those results suggest that D. rectus larvae selectively utilize alkaline-soluble nitrogenous substrates by using their highly alkaline midgut, and perhaps associate with microbes that enhance the nitrogen recycling in feces.

  6. Elementary budget of stag beetle larvae associated with selective utilization of nitrogen in decaying wood

    Science.gov (United States)

    Tanahashi, Masahiko; Ikeda, Hiroshi; Kubota, Kôhei

    2018-06-01

    Wood degradation by insects plays important roles for the forest matter cycling. Since wood is deficient in nitrogen compared to the insect body, wood-feeding insects need to assimilate the nitrogen selectively and discard an excess carbon. Such a stoichiometric imbalance between food and body will cause high metabolic cost; therefore, wood-feeding insects may somehow alleviate the stoichiometric imbalance. Here, we investigated the carbon and nitrogen budgets of the larvae of stag beetle, Dorcus rectus, which feed on decaying wood. Assimilation efficiency of ingested wood was 22%, and those values based on the carbon and nitrogen were 27 and 45%, respectively, suggesting the selective digestion of nitrogen in wood. Element-based gross growth efficiency was much higher for nitrogen (45%) than for carbon (3%). As a result, the larvae released 24% of the ingested carbon as volatile, whereas almost no gaseous exchange was observed for nitrogen. Moreover, solubility-based elementary analysis revealed that the larvae mainly utilized alkaline-soluble-water-insoluble fraction of wood, which is rich in nitrogen. Actually, the midgut of the larvae was highly alkaline (pH 10.3). Stag beetle larvae are known to exhibit coprophagy, and here we also confirmed that alkaline-soluble-water-insoluble nitrogen increased again from fresh feces to old feces in the field. Stable isotope analysis suggested the utilization of aerial nitrogen by larvae; however, its actual contribution is still disputable. Those results suggest that D. rectus larvae selectively utilize alkaline-soluble nitrogenous substrates by using their highly alkaline midgut, and perhaps associate with microbes that enhance the nitrogen recycling in feces.

  7. Alterations in carbon and nitrogen metabolism induced by water deficit in the stems and leaves of Lupinus albus L.

    Science.gov (United States)

    Pinheiro, C; Chaves, M M; Ricardo, C P

    2001-05-01

    Water deficit (WD) in Lupinus albus L. brings about tissue-specific responses that are dependent on stress intensity. Carbohydrate metabolism is very sensitive to changes in plant water status. Six days from withholding water (DAW), sucrose, glucose and fructose levels of the leaf blade had already increased over 5-fold, and the activities of SS and INV(A) had increased c. 1.5-2 times. From 9 DAW on, when stress intensity was more pronounced, these effects were reversed with fructose and glucose concentrations as well as INV(A) activity dropping in parallel. The stem (specifically the stele) responded to the stress intensification with striking increases in the concentration of sugars, N and S, and in the induction of thaumatin-like-protein and an increase in chitinase and peroxidase. At 13 DAW, the plants lost most of the leaves but on rewatering they fully recovered. Thus, the observed changes appear to contribute to a general mechanism of survival under drought, the stem playing a key role in that process.

  8. Metabolic and transcriptomic response of the wine yeast Saccharomyces cerevisiae strain EC1118 after an oxygen impulse under carbon-sufficient, nitrogen-limited fermentative conditions.

    Science.gov (United States)

    Orellana, Marcelo; Aceituno, Felipe F; Slater, Alex W; Almonacid, Leonardo I; Melo, Francisco; Agosin, Eduardo

    2014-05-01

    During alcoholic fermentation, Saccharomyces cerevisiae is exposed to continuously changing environmental conditions, such as decreasing sugar and increasing ethanol concentrations. Oxygen, a critical nutrient to avoid stuck and sluggish fermentations, is only discretely available throughout the process after pump-over operation. In this work, we studied the physiological response of the wine yeast S. cerevisiae strain EC1118 to a sudden increase in dissolved oxygen, simulating pump-over operation. With this aim, an impulse of dissolved oxygen was added to carbon-sufficient, nitrogen-limited anaerobic continuous cultures. Results showed that genes related to mitochondrial respiration, ergosterol biosynthesis, and oxidative stress, among other metabolic pathways, were induced after the oxygen impulse. On the other hand, mannoprotein coding genes were repressed. The changes in the expression of these genes are coordinated responses that share common elements at the level of transcriptional regulation. Beneficial and detrimental effects of these physiological processes on wine quality highlight the dual role of oxygen in 'making or breaking wines'. These findings will facilitate the development of oxygen addition strategies to optimize yeast performance in industrial fermentations. © 2014 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

  9. Anaerobic digestion of thermal pre-treated emulsified slaughterhouse wastes (TESW): Effect of trace element limitation on process efficiency and sludge metabolic properties.

    Science.gov (United States)

    Eftaxias, Alexandros; Diamantis, Vasileios; Aivasidis, Alexandros

    2018-06-01

    Slaughterhouse solid wastes, characterized by a high lipid content, are considered a valuable resource for energy production by means of anaerobic digestion technologies. Aim of this study was to examine the effect of trace element limitation on the mesophilic anaerobic digestion of thermally pre-treated emulsified slaughterhouse wastes (TESW). Under two distinct experimental periods (Period I - low and Period II - high trace element dosage respectively) a CSTR with sludge recirculation was operated at increasing organic loading rate (OLR) from 1.5 to 10 g L -1  d -1 . Under optimum conditions, COD removal was higher than 96%, biogas yield equal to 0.53 L g -1  COD feed and the biogas methane content 77%. Trace element limitation however, resulted in a dramatic decline in process efficiency, with VFA accumulation and events of extreme sludge flotation, despite that the soluble concentration of Ni, Co and Mo were between 12 and 28 μg L -1 . This is indicative of mass transfer limitations caused by lipids adsorption onto the anaerobic biomass. Copyright © 2018 Elsevier Ltd. All rights reserved.

  10. Short communication: Partial replacement of ground corn with algae meal in a dairy cow diet: Milk yield and composition, nutrient digestibility, and metabolic profile.

    Science.gov (United States)

    da Silva, G G; Ferreira de Jesus, E; Takiya, C S; Del Valle, T A; da Silva, T H; Vendramini, T H A; Yu, Esther J; Rennó, F P

    2016-11-01

    This study was undertaken to evaluate the effects of partially replacing dietary ground corn with a microalgae meal from Prototheca moriformis (composed of deoiled microalgae and soyhulls) on milk yield and composition, nutrient intake, total-tract apparent digestibility, and blood profile of lactating dairy cows. Twenty multiparous Holstein cows (57.7±49.4d in milk, 25.3±5.3 of milk yield, and 590±71kg of live weight at the start of experiment, mean ± standard deviation) were used in a cross-over design experiment, with 21-d periods. Diets were no microalgae meal (CON) or 91.8g/kg of microalgae meal partially replacing dietary ground corn (ALG). Cows showed similar milk yield and composition. The 3.5% fat-corrected milk production was 30.2±1.34kg/d for CON and 31.1±1.42kg/d for ALG. Despite cows having similar dry matter intake, ALG increased neutral detergent fiber and ether extract intake. In addition, cows fed ALG exhibited higher ether extract digestibility. No differences were detected in glucose, urea, amino-aspartate transferase, and gamma-glutamyl transferase blood concentrations. Feeding ALG increased the total cholesterol and high-density lipoprotein in blood compared with CON. The microalgae meal may partially replace ground corn in diets of lactating cows without impairing the animal's performance. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  11. Biological digestion

    International Nuclear Information System (INIS)

    Rosevear, A.

    1988-01-01

    This paper discusses the biological degradation of non-radioactive organic material occurring in radioactive wastes. The biochemical steps are often performed using microbes or isolated enzymes in combination with chemical steps and the aim is to oxidise the carbon, hydrogen, nitrogen and sulphur to their respective oxides. (U.K.)

  12. Brucella, nitrogen and virulence.

    Science.gov (United States)

    Ronneau, Severin; Moussa, Simon; Barbier, Thibault; Conde-Álvarez, Raquel; Zuniga-Ripa, Amaia; Moriyon, Ignacio; Letesson, Jean-Jacques

    2016-08-01

    The brucellae are α-Proteobacteria causing brucellosis, an important zoonosis. Although multiplying in endoplasmic reticulum-derived vacuoles, they cause no cell death, suggesting subtle but efficient use of host resources. Brucellae are amino-acid prototrophs able to grow with ammonium or use glutamate as the sole carbon-nitrogen source in vitro. They contain more than twice amino acid/peptide/polyamine uptake genes than the amino-acid auxotroph Legionella pneumophila, which multiplies in a similar vacuole, suggesting a different nutritional strategy. During these two last decades, many mutants of key actors in nitrogen metabolism (transporters, enzymes, regulators, etc.) have been described to be essential for full virulence of brucellae. Here, we review the genomic and experimental data on Brucella nitrogen metabolism and its connection with virulence. An analysis of various aspects of this metabolism (transport, assimilation, biosynthesis, catabolism, respiration and regulation) has highlighted differences and similarities in nitrogen metabolism with other α-Proteobacteria. Together, these data suggest that, during their intracellular life cycle, the brucellae use various nitrogen sources for biosynthesis, catabolism and respiration following a strategy that requires prototrophy and a tight regulation of nitrogen use.

  13. Intake, nutrient digestibility and nitrogen balance in lactating dairy cows fed diets containing sunflower cakeConsumo, digestibilidade dos nutrientes e balanço de nitrogênio em vacas leiteiras alimentadas com dietas contendo torta de girassol

    Directory of Open Access Journals (Sweden)

    Elzânia Sales Pereira

    2012-12-01

    Full Text Available The objective of this study was to evaluate the effect of different levels of sunflower cake (SC inclusion in the diets of lactating dairy cows on dry matter (DM intake, the apparent digestibility of dietary nutrients and nitrogen balance. Eight Holstein-Zebu cows with a milk yield of 20 ± 2 kg/day were allotted to a 4 × 4 replicated Latin square design, where were tested the effects of four levels of SC inclusion (0, 7, 14 and 21% of DM basis. Tifton-85 (Cynodon dactylon hay was used as roughage in a 60:40 roughage:concentrate ratio. The SC inclusion had no effect on dry matter, crude protein, organic matter (OM or total carbohydrate (TC intake (kg/day. However, a quadratic effect (P O objetivo deste estudo foi avaliar o efeito de diferentes níveis de inclusão de torta de girassol (TG na dieta de vacas em lactação sobre o consumo de matéria seca (MS, digestibilidade aparente dos nutrientes da dieta e balanço de nitrogênio. Oito vacas Girolanda com produção diária de leite de 20 ± 2 kg/dia foram distribuídas em delineamento em quadrado latino duplo 4x4, em que foram testados os efeitos de quatro níveis de inclusão da TG (0, 7, 14 e 21% MS. Foi utilizado o feno de Tifton-85 (Cynodon dactylon como volumoso em uma relação volumoso:concentrado de 60:40. A inclusão de TG não afetou o consumo (kg/dia de MS, proteína bruta, matéria orgânica (OM e carboidratos totais (CT. Entretanto, foi observado efeito quadrático (P < 0,05 no consumo (kg/dia de fibra em detergente neutro e carboidratos não-fibrosos (CNF. Não houve efeito da inclusão de TG na digestibilidade de MO, CT e CNF, assim como para o balanço de nitrogênio. Foi observado efeito linear para o nitrogênio endógeno basal (g/dia. A torta de girassol pode ser recomendada como um ingrediente de rações para vacas em lactação.

  14. Variability in amino acid digestibility and metabolizable energy of corn studied in cecectomized laying hens1.

    Science.gov (United States)

    Zuber, T; Rodehutscord, M

    2017-06-01

    To optimize the use of corn grain in diets for laying hens, differences in amino acid (AA) digestibility and metabolizable energy among different corn samples should be considered in feed formulation. The present study investigated the variability of AA digestibility and AMEn concentration of 20 corn samples in cecectomized laying hens. Corn grains were characterized based on their physical properties (thousand seed weight, test weight, grain density, and extract viscoelasticity), chemical composition (proximate nutrients, AA, minerals, and inositol phosphates), gross energy concentration, and in vitro solubility of nitrogen to study any relationship with AA digestibility or AMEn. The animal study comprised 4 Latin squares (6 × 6) distributed between 2 subsequent runs. Cecectomized LSL-Classic hens were individually housed in metabolism cages and fed either a basal diet containing 500 g/kg cornstarch or one of 20 corn diets, each replacing the cornstarch with one corn batch, for 8 days. During the last 4 d, feed intake was recorded and excreta were collected quantitatively. A linear regression approach was used to calculate AA digestibility of the corn. The digestibility of all AA differed significantly between the 20 corn batches, including Lys (digestibility range 64 to 85%), Met (86 to 94%), Thr (72 to 89%), and Trp (21 to 88%). The AMEn of the corn batches ranged between 15.7 and 17.1 MJ/kg DM. However, consistent correlations between AA digestibility or AMEn and the physical and chemical characteristics of the grains were not detected. Equations to predict AA digestibility or AMEn based on the grain's physical and chemical characteristics were calculated by multiple linear regressions. The explanatory power (adjusted R2;) of prediction equations was below 0.6 for the majority of AA and AMEn, and, thus, was not sufficiently precise for practical use. Possible explanations for the variation in AA digestibility and AMEn beyond the determined characteristics

  15. the chentical composition and in vitro digestibility of forage samples ...

    African Journals Online (AJOL)

    oesophageal fistulated sheep, are presented in Table l. Table I. The average chemicol composition and in vitro digestibility offorage samples selectecl by oesophageal fistuhted sheep duing dffirent months of the yeor on noturol pasture. Month. Acid de- Lignin. Nitrogen tergent fibre. Cellulose In vitro digest- ibility of organ-.

  16. Digestibility Is Similar between Commercial Diets That Provide Ingredients with Different Perceived Glycemic Responses and the Inaccuracy of Using the Modified Atwater Calculation to Calculate Metabolizable Energy

    Science.gov (United States)

    Asaro, Natalie J.; Guevara, Marcial A.; Berendt, Kimberley; Zijlstra, Ruurd; Shoveller, Anna K.

    2017-01-01

    Dietary starch is required for a dry, extruded kibble; the most common diet type for domesticated felines in North America. However, the amount and source of dietary starch may affect digestibility and metabolism of other macronutrients. The objectives of this study were to evaluate the effects of 3 commercial cat diets on in vivo and in vitro energy and macronutrient digestibility, and to analyze the accuracy of the modified Atwater equation. Dietary treatments differed in their perceived glycemic response (PGR) based on ingredient composition and carbohydrate content (34.1, 29.5, and 23.6% nitrogen-free extract for High, Medium, and LowPGR, respectively). A replicated 3 × 3 Latin square design was used, with 3 diets and 3 periods. In vivo apparent protein, fat, and organic matter digestibility differed among diets, while apparent dry matter digestibility did not. Cats were able to efficiently digest and absorb macronutrients from all diets. Furthermore, the modified Atwater equation underestimated measured metabolizable energy by approximately 12%. Thus, the modified Atwater equation does not accurately determine the metabolizable energy of high quality feline diets. Further research should focus on understanding carbohydrate metabolism in cats, and establishing an equation that accurately predicts the metabolizable energy of feline diets. PMID:29117110

  17. Digestibility Is Similar between Commercial Diets That Provide Ingredients with Different Perceived Glycemic Responses and the Inaccuracy of Using the Modified Atwater Calculation to Calculate Metabolizable Energy

    Directory of Open Access Journals (Sweden)

    Natalie J. Asaro

    2017-11-01

    Full Text Available Dietary starch is required for a dry, extruded kibble; the most common diet type for domesticated felines in North America. However, the amount and source of dietary starch may affect digestibility and metabolism of other macronutrients. The objectives of this study were to evaluate the effects of 3 commercial cat diets on in vivo and in vitro energy and macronutrient digestibility, and to analyze the accuracy of the modified Atwater equation. Dietary treatments differed in their perceived glycemic response (PGR based on ingredient composition and carbohydrate content (34.1, 29.5, and 23.6% nitrogen-free extract for High, Medium, and LowPGR, respectively. A replicated 3 × 3 Latin square design was used, with 3 diets and 3 periods. In vivo apparent protein, fat, and organic matter digestibility differed among diets, while apparent dry matter digestibility did not. Cats were able to efficiently digest and absorb macronutrients from all diets. Furthermore, the modified Atwater equation underestimated measured metabolizable energy by approximately 12%. Thus, the modified Atwater equation does not accurately determine the metabolizable energy of high quality feline diets. Further research should focus on understanding carbohydrate metabolism in cats, and establishing an equation that accurately predicts the metabolizable energy of feline diets.

  18. Consumption and utilization of experimentally altered corn by southern armyworm: Iron, nitrogen, and cyclic hydroxamates.

    Science.gov (United States)

    Manuwoto, S; Scriber, J M

    1985-11-01

    The effects of differential leaf water, leaf nitrogen and cyclic hydroxamate (DIMBOA) concentrations in corn seedlings were analyzed for a polyphagous insect, the southern armyworm (Spodoptera eridania Cram.). Six different combinations of nutrients and allelochemicals [DIMBOA = 2,4-dihydroxy-7-methoxy(2H)-benzoxazin-3(4H)-one] were generated using two corn genotypes (WF9 and CI3IA) and three fertility regimes (complete nutrient, Fe-deficient, and N-deficient solutions) in the University Biotron. Poorest larval growth was observed in the low-nitrogen treatments (1.2% and 1.7% leaf N) and was the result of both low consumption rates and high metabolic costs (low efficiency of conversion of digested food, ECD). Fastest growth rates were observed forthe larvae fed leaves from the high-nitrogen treatments (4.6% and 4.4% leaf N). It is noteworthy that these treatments also contained the highest concentration of cyclic hydroxamates, which are generally believed to be the primary defensive chemicals mediating resistance against the European corn borer,Ostrinia nubilalis (Hubner). If these hydroxamates do have any deleterious or costly effects (perhaps accounting for a large portion of metabolic expenditures), the high digestibility of the leaf tissue and the increased consumption rates more than compensate, resulting in rapid growth (growth rate = consumption rate × approximate digestibility × efficiency of conversion of the digested food). These studies illustrate that variation in key nutrients and allelochemicals within a single plant species (Zea mays L.) may have significantly different effects upon various potential leaf-chewing caterpillars, such as these armyworms versus corn borers (which cannot handle the cyclic hydroxamates, even if provided with young nutritious leaf tissues).

  19. Effect of constant digestible protein intake and varying digestible energy levels on energy and protein utilization in Nile tilapia

    NARCIS (Netherlands)

    Haidar, M.N.; Bleeker, S.; Heinsbroek, L.T.N.; Schrama, J.W.

    2018-01-01

    In literature, the variability in the estimated optimal digestible protein to digestible energy ratio (DP/DE) is high. The present study aimed to estimate the optimal DP/DE ratio in Nile tilapia (Oreochromis niloticus) using different criteria (performance, energy and nitrogen balances parameters).

  20. 76 FR 34717 - National Institute of Diabetes and Digestive and Kidney Diseases; Notice of Closed Meetings

    Science.gov (United States)

    2011-06-14

    ... Digestive and Kidney Diseases Special Emphasis Panel, Teen-LABS. Date: July 15, 2011. Time: 2 p.m. to 2 p.m... Nos. 93.847, Diabetes, Endocrinology and Metabolic Research; 93.848, Digestive Diseases and Nutrition...

  1. Low cost of gastric acid secretion during digestion in ball pythons.

    Science.gov (United States)

    Nørgaard, Simon; Andreassen, Kim; Malte, Christian Lind; Enok, Sanne; Wang, Tobias

    2016-04-01

    Due to their large metabolic responses to digestion (specific dynamic action, SDA), snakes represent an interesting animal group to identify the underlying mechanisms for the postprandial rise in metabolism. The SDA response results from the energetic costs of many different processes ranging over prey handling, secretions by the digestive system, synthesis of enzymes, plasticity of most visceral organs, as well as protein synthesis and nitrogen excretion. The contribution of the individual mechanisms, however, remains elusive. Gastric acid secretion has been proposed to account for more than half of the SDA response, while other studies report much lower contributions of the gastric processes. To investigate the energetic cost of gastric acid secretion, ball pythons (Python regius) were fed meals with added amounts of bone meal (up to 25 g bone meal kg(-1) snake) to achieve a five-fold rise in the buffer capacity of the meals. Direct measurements within the stomach lumen showed similar reduction in gastric pH when buffer capacity was increased, but we found no effects on the rise in oxygen consumption over the first three days of digestion. There was, however, a slower return of oxygen consumption to resting baseline. We conclude that gastric acid secretion only contributes modestly to the SDA response and propose that post-absorptive processes, such as increased protein synthesis, are likely to underlie the SDA response. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Dietary N,N-dimethylglycine supplementation improves nutrient digestibility and attenuates pulmonary hypertension syndrome in broilers.

    Science.gov (United States)

    Kalmar, I D; Cools, A; Buyse, J; Roose, P; Janssens, G P J

    2010-12-01

    N,N-dimethylglycine (DMG) is an intermediary metabolite in cellular choline and betaine metabolism. The present trial aimed to evaluate the effect of dietary DMG on nutrient digestibility and development of pulmonary hypertension syndrome in broilers. A total of 64 14-day-old broiler hens (Ross-308) were raised until age 40 days under cold environmental temperature conditions (15 °C) and were fed a high energy feed in order to incite pulmonary hypertension. Birds were randomly assigned to two groups of which each group had eight replicate pens of four birds each. Test diets contained 0 or 167 mg Na-DMG (Taminizer(®) D; Taminco N.V., Ghent, Belgium)/kg feed. N,N-dimethylglycine supplementation resulted in a significant improvement in apparent faecal digestibility of crude protein and nitrogen-free extract. Further, fulminant ascites was numerically lowered by DMG and incidence of pulmonary hypertension decreased significantly from 44.8% in the control group to 14.6% in the DMG group. Finally, fasted plasma level of non-esterified fatty acids (NEFA) was twofold in the control group in relation to the DMG group. In conclusion, these data demonstrate beneficial effects of DMG on digestibility of non-fat fractions, on fat metabolism and on progression towards broiler ascites syndrome. © 2010 Blackwell Verlag GmbH.

  3. Nitrogen balance of healthy Dutch women before and during pregnancy

    NARCIS (Netherlands)

    Mojtahedi, M.; Groot, de C.P.G.M.; Boekholt, H.A.; Raaij, van J.M.A.

    2002-01-01

    Background: Experimental studies including longitudinal nitrogen balance studies could provide insight into protein metabolism in pregnancy. Objective: Our aim was to determine the development of nitrogen balance during pregnancy compared with nitrogen balance before pregnancy in women consuming

  4. Nutrient digestibility parameters as a tool for analysis of the intestinal health of broiler chickens

    Directory of Open Access Journals (Sweden)

    Anderson Mori

    2016-09-01

    Full Text Available The study was performed with the objective of verifying raw soy feed, oxidized oil feed, and a control group. Performance evaluation was done at 7, 14, and 21 days of age. Metabolism assay was carried out between the 17th and 20th days for nutrient digestibility analysis. On the 21st day, two birds per repetition were sent for necropsy and collection of intestine fragments (duodenum and jejunum for histomorphometric analysis. Eight to 14 days after treatment with Salmonella, individuals showed lower feed intake and feed conversion than the control group. Treatment with coccidiosis decreased all performance parameters in the control. Raw soybeans and oxidized oil induce lower weight gain and higher feed conversion compared to the control feed. Unlike after 14 days, at 21 days treatment with salmonella a decrease in weight gain was noted. For the group challenged by coccidiosis feed intake, the feed conversion remained lower than the control group. Undesirable effects on performance in the groups fed raw soybean and oxidized oil remained at up to 21 days. In the evaluation of digestibility, it was observed that raw soy had lower values for digestibility of dry matter, ether extract, and nitrogen balance due to intake. In addition, a lower ratio of villus:crypt measurements was observed. Lower villus height was found in the duodenum of the group challenged by coccidiosis. This group presented a positive correlation between the digestibility of ether extract and the duodenum, indicating that increased villus height implies an increased digestibility of ether extract. The results obtained for the jejunum showed a positive correlation with villus height in groups challenged by coccidiosis, raw soybeans, and oxidized oil; and to crypt depth in the group challenged with oxidized oil. The information obtained in the present study demonstrates that nutrient digestibility parameters can be useful tools for the analysis of the intestinal health of broiler

  5. The effect of zilpaterol hydrochloride supplementation on energy metabolism and nitrogen and carbon retention of steers fed at maintenance and fasting intake levels.

    Science.gov (United States)

    Walter, L J; Cole, N A; Jennings, J S; Hutcheson, J P; Meyer, B E; Schmitz, A N; Reed, D D; Lawrence, T E

    2016-10-01

    An indirect calorimetry trial examined energy metabolism, apparent nutrient digestibility, C retention (CR), and N retention (NR) of cattle supplemented with zilpaterol hydrochloride (ZH). Beef steers ( = 20; 463 ± 14 kg) blocked ( = 5) by weight and source were individually fed and adapted to maintenance energy intake for 21 d before allotment to ZH (90 mg/steer∙d) or no β-adrenergic agonist treatment (control [CONT]) for 20 d (455 ± 14 kg at the start of treatment). Respiration chambers = 4 were used to quantify heat production (HP) during maintenance (d 12 to 16 of the ZH period) and fasting heat production (FHP; d 19 to 20 of ZH period; total 4 d of fast). Steers were harvested after a 6-d ZH withdrawal and carcasses were graded 24 h after harvest. Control cattle lost more BW ( maintenance whereas the BW loss of ZH-treated steers was greater ( maintenance ( = 0.04; 23.6 L/kgBW for ZH-treated and 22.4 L/kg BW for CONT). Digestible energy and ME did not differ ( ≥ 0.19); however, urinary energy was greater ( = 0.05; 0.091 Mcal for CONT and 0.074 Mcal for ZH-treated) in CONT cattle. Steers treated with ZH tended to have greater HP ( = 0.09; 12.44 Mcal for ZH-treated and 11.69 Mcal for CONT), but the effect was reduced on a BW basis ( = 0.12; 0.126 Mcal/kg BW0.75 for ZH-treated and 0.120 Mcal/kg BW0.75 for CONT vs. 0.120 Mcal/kg BW). No treatment difference in FHP was observed ( ≥ 0.32) although CO production (L/steer) increased with ZH treatment ( = 0.04; 1,423 L/steer for ZH-treated and 1,338 L/steer for CONT). Control cattle excreted more ( = 0.05) N in urine (39.8 g/d for CONT and 32.4 g/d for ZH-treated); therefore, NR ( = 0.07; 22.14 g/d for ZH-treated and 14.12 g/d for CONT steers) tended to be greater for ZH-fed steers. Steers treated with ZH lost more C via CO ( = 0.04; 1,036.9 g/d for ZH-treated and 974.3 g/d for CONT) although total CR did not differ ( ≥ 0.23). Empty BW, HCW, and harvest yields (g/kg empty BW) were not different ( ≥ 0

  6. Water balance and N-metabolism in broccoli (Brassica oleracea L. var. Italica) plants depending on nitrogen source under salt stress and elevated CO2.

    Science.gov (United States)

    Zaghdoud, Chokri; Carvajal, Micaela; Ferchichi, Ali; Del Carmen Martínez-Ballesta, María

    2016-11-15

    Elevated [CO2] and salinity in the soils are considered part of the effects of future environmental conditions in arid and semi-arid areas. While it is known that soil salinization decreases plant growth, an increased atmospheric [CO2] may ameliorate the negative effects of salt stress. However, there is a lack of information about the form in which inorganic nitrogen source may influence plant performance under both conditions. Single factor responses and the interactive effects of two [CO2] (380 and 800ppm), three different NO3(-)/NH4(+) ratios in the nutrient solution (100/0, 50/50 and 0/100, with a total N concentration of 3.5mM) and two NaCl concentrations (0 and 80mM) on growth, leaf gas exchange parameters in relation to root hydraulic conductance and N-assimilating enzymes of broccoli (Brassica oleracea L. var. Italica) plants were determined. The results showed that a reduced NO3(-) or co-provision of NO3(-) and NH4(+) could be an optimal source of inorganic N for broccoli plants. In addition, elevated [CO2] ameliorated the effect of salt exposure on the plant growth through an enhanced rate of photosynthesis, even at low N-concentration. However, NO3(-) or NO3(-)/NH4(+) co-provision display differential plant response to salt stress regarding water balance, which was associated to N metabolism. The results may contribute to our understanding of N-fertilization modes under increasing atmospheric [CO2] to cope with salt stress, where variations in N nutrition significantly influenced plant response. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Nitrogen metabolism, acid-base regulation, and molecular responses to ammonia and acid infusions in the spiny dogfish shark (Squalus acanthias).

    Science.gov (United States)

    Nawata, C Michele; Walsh, Patrick J; Wood, Chris M

    2015-07-01

    Although they are ureotelic, marine elasmobranchs express Rh glycoproteins, putative ammonia channels. To address questions raised by a recent study on high environmental ammonia (HEA) exposure, dogfish were intravascularly infused for 24 h at 3 ml kg(-1) h(-1) with isosmotic NaCl (500 mmol l(-1), control), NH4HCO3 (500 mmol l(-1)), NH4Cl (500 mmol l(-1)), or HCl (as 125 mmol l(-1) HCl + 375 mmol l(-1) NaCl). While NaCl had no effect on arterial acid-base status, NH4HCO3 caused mild alkalosis, NH4Cl caused strong acidosis, and HCl caused lesser acidosis, all predominantly metabolic in nature. Total plasma ammonia (T(Amm)) and excretion rates of ammonia (J(Amm)) and urea-N (J(Urea-N)) were unaffected by NaCl or HCl. However, despite equal loading rates, plasma T(Amm) increased to a greater extent with NH4Cl, while J(Amm) increased to a greater extent with NH4HCO3 due to much greater increases in blood-to-water PNH3 gradients. As with HEA, both treatments caused large (90%) elevations of J(Urea-N), indicating that urea-N synthesis by the ornithine-urea cycle (OUC) is driven primarily by ammonia rather than HCO3(-). Branchial mRNA expressions of Rhbg and Rhp2 were unaffected by NH4HCO3 or NH4Cl, but v-type H(+)-ATPase was down-regulated by both treatments, and Rhbg and Na(+)/H(+) exchanger NHE2 were up-regulated by HCl. In the kidney, Rhbg was unresponsive to all treatments, but Rhp2 was up-regulated by HCl, and the urea transporter UT was up-regulated by HCl and NH4Cl. These responses are discussed in the context of current ideas about branchial, renal, and OUC function in this nitrogen-limited predator.

  8. Effects of nonstructural carbohydrates and protein sources on intake, apparent total tract digestibility, and ruminal metabolism in vivo and in vitro with high-concentrate beef cattle diets.

    Science.gov (United States)

    Rotger, A; Ferret, A; Calsamiglia, S; Manteca, X

    2006-05-01

    To investigate the effects of synchronizing nonstructural carbohydrate (NSC) and protein degradation on intake and rumen microbial fermentation, four ruminally fistulated Holstein heifers (BW = 132.3 +/- 1.61 kg) fed high-concentrate diets were assigned to a 4 x 4 Latin square design with a 2 x 2 factorial arrangement of treatments studied in vivo and in vitro with a dual-flow continuous culture system. Two NSC sources (barley and corn) and 2 protein sources [soybean meal (SBM) and sunflower meal (SFM)] differing in their rate and extent of ruminal degradation were combined resulting in a synchronized rapid fermentation diet (barley-SFM), a synchronized slow fermentation diet (corn-SBM), and 2 unsynchronized diets with a rapidly and a slowly fermenting component (barley-SBM, and corn-SFM). In vitro, the fermentation profile was studied at a constant pH of 6.2, and at a variable pH with 12 h at pH 6.4 and 12 h at pH 5.8. Synchronization tended to result in greater true OM digestion (P = 0.072), VFA concentration (P = 0.067), and microbial N flow (P = 0.092) in vitro, but had no effects on in vivo fermentation pattern or on apparent total tract digestibility. The NSC source affected the efficiency of microbial protein synthesis in vitro, tending to be greater (P = 0.07) for barley-based diets, and in vivo, the NSC source tended to affect intake. Dry matter and OM intake tended to be greater (P > or = 0.06) for corn- than barley-based diets. Ammonia N concentration was lower in vitro (P = 0.006) and tended to be lower in vivo (P = 0.07) for corn- than barley-based diets. In vitro, pH could be reduced from 6.4 to 5.8 for 12 h/d without any effect on ruminal fermentation or microbial protein synthesis. In summary, ruminal synchronization seemed to have positive effects on in vitro fermentation, but in vivo recycling of endogenous N or intake differences could compensate for these effects.

  9. INTESTINAL MICROBIOTA IN DIGESTIVE DISEASES

    Directory of Open Access Journals (Sweden)

    Maria do Carmo Friche PASSOS

    2017-07-01

    Full Text Available ABSTRACT BACKGROUND In recent years, especially after the development of sophisticated metagenomic studies, research on the intestinal microbiota has increased, radically transforming our knowledge about the microbiome and its association with health maintenance and disease development in humans. Increasing evidence has shown that a permanent alteration in microbiota composition or function (dysbiosis can alter immune responses, metabolism, intestinal permeability, and digestive motility, thereby promoting a proinflammatory state. Such alterations can mainly impair the host’s immune and metabolic functions, thus favoring the onset of diseases such as diabetes, obesity, digestive, neurological, autoimmune, and neoplastic diseases. This comprehensive review is a compilation of the available literature on the formation of the complex intestinal ecosystem and its impact on the incidence of diseases such as obesity, non-alcoholic steatohepatitis, irritable bowel syndrome, inflammatory bowel disease, celiac disease, and digestive neoplasms. CONCLUSION: Alterations in the composition and function of the gastrointestinal microbiota (dysbiosis have a direct impact on human health and seem to have an important role in the pathogenesis of several gastrointestinal diseases, whether inflammatory, metabolic, or neoplastic ones.

  10. Fontes de carboidratos e ionóforo em dietas contendo óleo vegetal para ovinos: digestibilidade, balanço de nitrogênio e fluxo portal de nutrientes Carbohydrate sources and ionophore in sheep diets with vegetal oil: digestibility, nitrogen balance and portal flux of nutrients

    Directory of Open Access Journals (Sweden)

    Gisele Fernanda Mouro

    2006-10-01

    Full Text Available Os objetivos neste trabalho foram avaliar a utilização de duas fontes de carboidratos (casca de soja e milho, com a utilização ou não de monensina em dietas com alta densidade lipídica, e seus efeitos sobre a digestibilidade dos nutrientes, o balanço de nitrogênio e o fluxo portal de nutrientes em ovinos. Adotou-se o método de coleta total de fezes e urina para determinação da digestibilidade e do balanço de nitrogênio. O fluxo líquido de nutrientes foi calculado pelo princípio de Fick. Foram utilizados quatro ovinos (54 kg de PV da raça Corriedale com três cateteres implantados (veia e artéria mesentérica e veia porta. A ingestão, a excreção fecal, a digestão e a digestibilidade de MS, MO e EE não foram influenciadas pelos tratamentos. A ingestão, a digestão e a digestibilidade da FDN foram maiores para as dietas com casca de soja (757,0; 531,1 g/dia e 70,2% que para aquelas com milho (392,3; 199,9 g/dia e 51,0%, enquanto a dos carboidratos não-fibrosos (CNF, foram maiores para as dietas com milho (474,6, 416,8 g/dia e 87,8% que para aquelas com casca de soja (148,0; 97,8 g/dia e 66,1%. A concentração de energia expressa como NDT foi maior nas dietas com milho (80,2% que naquelas com casca de soja (76,7%. Não houve efeito da utilização da monensina nos parâmetros de digestibilidade e balanço de nitrogênio. A excreção fecal da proteína foi menor e a digestibilidade maior para as dietas com milho. A concentração portal e arterial de nitrogênio alfa amino (N alfa-amino foi menor para as dietas com monensina (3,161 e 2,922 e 3,530 e 3,218 mM, respectivamente. A concentração portal (0,419 vs 0,516 mM, a diferença venosa-arterial (0,230 vs 0,317 mM e o fluxo portal de amônia (26,119 vs 37,041 mM/h foram menores para as dietas com milho.The objectives of this trial were to evaluate the effects of two carbohydrate sources (soybean hulls and corn grain with and without monensin on digestibility, nitrogen

  11. Effects of different digestible carbohydrates on bile acid metabolism and SCFA production by human gut micro-flora grown in an in vitro semi-continuous culture.

    Science.gov (United States)

    Zampa, Andrea; Silvi, Stefania; Fabiani, Roberto; Morozzi, Guido; Orpianesi, Carla; Cresci, Alberto

    2004-02-01

    The main source of carbon in the human large intestine comes from carbohydrates like starches and oligosaccharides which remain unchanged by gastric digestion. These polysaccharides are metabolised in the colon by saccharolytic bacteria whose composition is dependent upon the substrate availability. Among the metabolites produced, the short-chain fatty acids (SCFA) are important for colon function and to prevent diseases. In particular, butyrate affects several cellular functions (proliferation, membrane synthesis, sodium absorption), and it has been shown to be protective against colorectal cancer. In addition, faecal bacteria are responsible for the conversion of primary bile acids (BA) to secondary BA, which are considered tumor promoters. In this study we investigated the in vitro effect of different substrates (CrystaLean starch, xylo-oligosaccharides, corn starch) supplied to human faecal micro-flora, on the SCFA production, on the bowel micro-flora composition and on the primary BA conversion rate. In addition, with corn starch as substrate, we considered the effect of enriching normal human faecal micro-flora with lactobacilli and bifidobacteria, on the above reported parameters.

  12. Desempenho e excreção de nitrogênio de leitões dos 9 aos 25 kg alimentados com dietas com diferentes níveis de lisina digestível e proteína bruta Performance and nitrogen excretion for pigs from 9 to 25 kg submitted to the diets with different levels of digestible lysine and crude protein

    Directory of Open Access Journals (Sweden)

    Márcio Gilberto Zangeronimo

    2007-10-01

    crude protein (CP and digestible lysine (LYSD on the performance and nitrogen (N excretion of piglets in the initial phase. In experiment 1, 80 barrows and females (initial weight of the 9.1 kg ± 1.2 kg and final weight of the 21.5 ± 4.8 kg, crossbred (Landrace x Large White, were distributed to a randomized blocks in factorial scheme 2 x 4 (two levels of CP 16 and 18% - and four levels of LYSD (0.7; 0.9; 1.1 and 1.3% with five replications and two animals per experimental unit, during 35 days. The average daily weight gain (ADG, average daily feed intake (ADFI and feed:gain ratio (F:G were evaluated. In experiment 2, 32 barrows (25.0 ± 1.3 kg, from experiment I, were individually allotted in metabolic cages (experimental unit, during 11 days, to evaluate the ingested N, N in feces and N in urine . The diets were formulated with corn, soybean meal and modified powder milk, supplemented with vitamins and minerals. The amino acids methionine and threonine were corrected in function of the lysine levels, following the ideal protein concept. No interaction LYSD x CP was observed for neither studied variable. Average daily gain and F:G showed a quadratic effect for the LYSD levels and were better in the animals fed diets with levels of 1.04 and 1.09%, respectively. The levels of N in the fezes showed crescent linear effect with the LYSD and CP levels, while the N levels in the urine showed quadratic effect with LYSD levels, with lower excretion for the level of 1.03% in the ration. No influence was observed for LYSD and CP level on ADFI and N in fezes. The level of 1.05% LYSD in diets with 16 and 18% CP provide best performance and lower excretion of de N in dejects of the swine.

  13. Proteins of Bacuri almonds: nutritional value and in vivo digestibility

    Directory of Open Access Journals (Sweden)

    Magalli Costa Barbosa Lima e Silva

    2014-03-01

    Full Text Available Bacuri (Scheelea phalerata Mart. is a type of palm fruit tree widely distributed in the Brazilian Cerrado. The objective of this paper was to study the almonds of bacuri, in their form in natura and processed, focusing on their nutritional value through the profile of amino acids, anti-nutritional factors and in vivo digestibility. Raw and toasted samples of the almond presented a high level of proteins and fiber. Proteins of raw bacuri almond showed no limiting amino acid when compared to the ones recommended by FAO/WHO, and histidine was the most limiting essential amino acid in the toasted almonds. The almond of bacuri does not present anti- nutritional factors. In an assay with rats fed with control (casein, tests (bacuri almond flours and aproteic diets, we verified the quantity of ration ingested and body weight gain, determining the urinary and metabolic nitrogen. Rats treated with the test diets presented inferior values of True Digestibility (DV, (82.9 and 72.3%, respectively for the raw and toasted almonds when compared to the control group (92.3%. The raw bacuri almond presented a superior nutritional value to the one found in the toasted almond.

  14. Engineering Digestion: Multiscale Processes of Food Digestion.

    Science.gov (United States)

    Bornhorst, Gail M; Gouseti, Ourania; Wickham, Martin S J; Bakalis, Serafim

    2016-03-01

    Food digestion is a complex, multiscale process that has recently become of interest to the food industry due to the developing links between food and health or disease. Food digestion can be studied by using either in vitro or in vivo models, each having certain advantages or disadvantages. The recent interest in food digestion has resulted in a large number of studies in this area, yet few have provided an in-depth, quantitative description of digestion processes. To provide a framework to develop these quantitative comparisons, a summary is given here between digestion processes and parallel unit operations in the food and chemical industry. Characterization parameters and phenomena are suggested for each step of digestion. In addition to the quantitative characterization of digestion processes, the multiscale aspect of digestion must also be considered. In both food systems and the gastrointestinal tract, multiple length scales are involved in food breakdown, mixing, absorption. These different length scales influence digestion processes independently as well as through interrelated mechanisms. To facilitate optimized development of functional food products, a multiscale, engineering approach may be taken to describe food digestion processes. A framework for this approach is described in this review, as well as examples that demonstrate the importance of process characterization as well as the multiple, interrelated length scales in the digestion process. © 2016 Institute of Food Technologists®

  15. Methods of ammonia removal in anaerobic digestion: a review.

    Science.gov (United States)

    Krakat, Niclas; Demirel, Burak; Anjum, Reshma; Dietz, Donna

    2017-10-01

    The anaerobic digestion of substrates with high ammonia content has always been a bottleneck in the methanisation process of biomasses. Since microbial communities in anaerobic digesters are sensitive to free ammonia at certain conditions, the digestion of nitrogen-rich substrates such as livestock wastes may result in inhibition/toxicity eventually leading to process failures, unless appropriate engineering precautions are taken. There are many different options reported in literature to remove ammonia from anaerobic digesters to achieve a safe and stable process so that along with high methane yields, a good quality of effluents can also be obtained. Conventional techniques to remove ammonia include physical/chemical methods, immobilization and adaptation of microorganisms, while novel methods include ultrasonication, microwave, hollow fiber membranes and microbial fuel cell applications. This paper discusses conventional and novel methods of ammonia removal from anaerobic digesters using nitrogen-rich substrates, with particular focus on recent literature available about this topic.

  16. INVITRO DIGESTIBILITY OF PROTEIN FROM BARLEY AND OTHER CEREALS

    DEFF Research Database (Denmark)

    Buchmann, N. B.

    1979-01-01

    An in vitro method for measuring barley protein digestibility is presented. Samples were first incubated with pepsin in HCl; pancreatin was then added concomitantly with a bacteriostatic borate buffer. After TCA-precipitation, soluble nitrogen was measured. The digestion was unaffected...... by accumulated free amino acids. There were no free amino acids following pepsin treatment, but the essential ones were well liberated by pancreatin. Results for barley grown in the field or in pots, and for decortified barley fractions agreed with true digestibility values determined with rats. Of these samples...... digestibility depended on the type of enzyme and on the enzyme-to-substrate ratio....

  17. The influence of straw meal on the crude protein and amino acid metabolism and the digestibility of crude nutrients in broiler breeding hens. 1

    International Nuclear Information System (INIS)

    Zander, R.; Gruhn, K.; Hennig, A.

    1987-01-01

    The metabolization of the straw N and the influence of the straw on N excretion in urine were studied in 2 experiments with colostomized broiler hens and with 15 N-labelled wheat straw as well as 15 N-labelled wheat. In experiment 1 the test animals divided up into 4 groups received 0 g, 20 g, 30 g and 40 g straw meal per animal and day in addition to 120 g mixed feed. The daily 15 N excess ( 15 N') intake from the straw was 18.4 mg, 27.5 mg and 36.7 mg. The amount of 15 N' daily consumed with the labelled wheat in experiment 2 was 119.7 mg. 40 g straw meal resulted in a significantly increased amount of urine (p 15 N' of the labelled wheat was not influenced by the straw meal supplement. The productive 15 N' of the straw increased from 3.8 mg/animal and day (20 g straw) to 13.4 mg/animal and day (40 g straw). In contrast to 15 N wheat, straw as a 15 N source resulted in a lower labelling of uric acid N in comparison with urine N. It can be assumed that the changed metabolization of the straw N is influenced by microbial processes in the intestines. (author)

  18. Elevated atmospheric CO2 and increased nitrogen deposition : effects on C and N metabolism and growth of the peat moss Sphagnum recurvum P. Beauv. var. mucronatum (Russ.) Warnst

    NARCIS (Netherlands)

    van der Heijden, E; Verbeek, S.K.; Kuiper, P.J C

    Sphagnum bogs play an important role when considering the impacts of global change on global carbon and nitrogen cycles. Sphagnum recurvum P. Beauv. var. mucronatum (Russ.) was grown at 360 (ambient) and 700 mu L L-1 (elevated) atmospheric [CO2] in combination with different nitrogen deposition

  19. 21 CFR 862.1770 - Urea nitrogen test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urea nitrogen test system. 862.1770 Section 862....1770 Urea nitrogen test system. (a) Identification. A urea nitrogen test system is a device intended to measure urea nitrogen (an end-product of nitrogen metabolism) in whole blood, serum, plasma, and urine...

  20. Effects of Coated Compound Proteases on Apparent Total Tract Digestibility of Nutrients and Apparent Ileal Digestibility of Amino Acids for Pigs.

    Science.gov (United States)

    Pan, L; Zhao, P F; Yang, Z Y; Long, S F; Wang, H L; Tian, Q Y; Xu, Y T; Xu, X; Zhang, Z H; Piao, X S

    2016-12-01

    Two experiments were conducted to evaluate effects of coated compound proteases (CC protease) on apparent total tract digestibility (ATTD) of nitrogen (N) and energy, and apparent ileal digestibility (AID) of amino acids (AA) and nutrients in diets for pigs. In Exp. 1, 12 crossbred barrows (initial body weight: 20.14±1.71 kg) were housed in individual metabolism crates and allotted into 2 treatments with 6 piglets per treatment according to weight in a randomized complete block design. The 2 diets were corn-soybean meal basal diets with (0.2 g/kg) or without CC protease supplementation. The CC protease supplementation increased (pdigestible and metabolizable N and energy values and the digestibility and retention rate of N in the diet. The ATTD of energy and nutrients had been improved (pdigestibility of nutrients was unaffected. Overall, the CC protease improved the ATTD of N and energy and AID of some indispensible AA and nutrients in the corn-soybean meal diet for pigs. Therefore, the CC protease supplement could improve the utilization of protein in the corn-soybean meal diet and thus contribute to lower N excretion to the environment.

  1. Nitrogen retention and water balance in animals fed medium protein ...

    African Journals Online (AJOL)

    amount of nitrogen, in contrast to control animals that lost 2.4% nitrogen via the faeces. Inadequate drinking caused decreased excretion of urea. The improved nitrogen retention coupled with high rates of urea recycling enhances nutrients digestion and consequently the animals' absorptive capabilities. . (Afr. J. Biomed.

  2. Effects of Synchronization of Carbohydrate and Protein Supply in Total Mixed Ration with Korean Rice Wine Residue on Ruminal Fermentation, Nitrogen Metabolism and Microbial Protein Synthesis in Holstein Steers

    Directory of Open Access Journals (Sweden)

    Min Yu Piao

    2012-11-01

    Full Text Available Three Holstein steers in the growing phase, each with a ruminal cannula, were used to test the hypothesis that the synchronization of the hourly rate of carbohydrate and nitrogen (N released in the rumen would increase the amount of retained nitrogen for growth and thus improve the efficiency of microbial protein synthesis (EMPS. In Experiment 1, in situ degradability coefficients of carbohydrate and N in feeds including Korean rice wine residue (RWR were determined. In Experiment 2, three total mixed ration (TMR diets having different rates of carbohydrate and N release in the rumen were formulated using the in situ degradability of the feeds. All diets were made to contain similar contents of crude protein (CP and neutral detergent fiber (NDF but varied in their hourly pattern of nutrient release. The synchrony index of the three TMRs was 0.51 (LS, 0.77 (MS and 0.95 (HS, respectively. The diets were fed at a restricted level (2% of the animal’s body weight in a 3×3 Latin-square design. Synchronizing the hourly supply of energy and N in the rumen did not significantly alter the digestibility of dry matter, organic matter, crude protein, NDF or acid detergent fiber (ADF (p>0.05. The ruminal NH3-N content of the LS group at three hours after feeding was significantly higher (p0.05. In addition, the purine derivative (PD excretion in urine and microbial-N production (MN among the three groups were not significantly different (p>0.05. In conclusion, synchronizing dietary energy and N supply to the rumen did not have a major effect on nutrient digestion or microbial protein synthesis (MPS in Holstein steers.

  3. Digestibility of the cottonseed meal with or without addition of protease and phytase enzymes in swine diet - doi: 10.4025/actascianimsci.v34i3.12360

    Directory of Open Access Journals (Sweden)

    Maria do Carmo Mouhaupt Marques Ludke

    2012-05-01

    Full Text Available This study evaluated the digestibility of cottonseed meal with or without addition of enzymes (phytase and protease for growing pigs. It was used 18 barrows, housed in metabolism cages, distributed in a completely randomized design, standardizing body weight (bw with average of 25.8 ± 3.6 kg, with three treatments and six repetitions. The treatments consisted of a reference diet based on corn and soybean meal, the second treatment with replacement of 30% of the reference diet by cottonseed meal without enzymes, and the third with 30% of the reference diet replaced by cottonseed meal with added enzymes. Was determined the digestible protein, digestible energy, digestibility of dry matter, energy and protein. It was also registered the balance of nitrogen and phosphorus. The use of cottonseed meal with the addition of enzymes in diets for growing pigs has no effect on the digestibility of dry matter, gross energy and crude protein, but improved the absorption of phosphorus, consequently reducing its excretion in the feces. There was no improvement in nitrogen balance in the diets containing cottonseed meal with enzymes.

  4. An update on the use of benzoate, phenylacetate and phenylbutyrate ammonia scavengers for interrogating and modifying liver nitrogen metabolism and its implications in urea cycle disorders and liver disease.

    Science.gov (United States)

    De Las Heras, Javier; Aldámiz-Echevarría, Luis; Martínez-Chantar, María-Luz; Delgado, Teresa C

    2017-04-01

    Ammonia-scavenging drugs, benzoate and phenylacetate (PA)/phenylbutyrate (PB), modulate hepatic nitrogen metabolism mainly by providing alternative pathways for nitrogen disposal. Areas covered: We review the major findings and potential novel applications of ammonia-scavenging drugs, focusing on urea cycle disorders and liver disease. Expert opinion: For over 40 years, ammonia-scavenging drugs have been used in the treatment of urea cycle disorders. Recently, the use of these compounds has been advocated in acute liver failure and cirrhosis for reducing hyperammonemic-induced hepatic encephalopathy. The efficacy and mechanisms underlying the antitumor effects of these ammonia-scavenging drugs in liver cancer are more controversial and are discussed in the review. Overall, as ammonia-scavenging drugs are usually safe and well tolerated among cancer patients, further studies should be instigated to explore the role of these drugs in liver cancer. Considering the relevance of glutamine metabolism to the progression and resolution of liver disease, we propose that ammonia-scavenging drugs might also be used to non-invasively probe liver glutamine metabolism in vivo. Finally, novel derivatives of classical ammonia-scavenging drugs with fewer and less severe adverse effects are currently being developed and used in clinical trials for the treatment of acute liver failure and cirrhosis.

  5. Metabolic profiling of two maize (Zea mays L.) inbred lines inoculated with the nitrogen fixing plant-interacting bacteria Herbaspirillum seropedicae and Azospirillum brasilense

    Science.gov (United States)

    Brusamarello-Santos, Liziane Cristina; Gilard, Françoise; Brulé, Lenaïg; Quilleré, Isabelle; Gourion, Benjamin; Ratet, Pascal; Maltempi de Souza, Emanuel; Lea, Peter J.; Hirel, Bertrand

    2017-01-01

    Maize roots can be colonized by free-living atmospheric nitrogen (N2)-fixing bacteria (diazotrophs). However, the agronomic potential of non-symbiotic N2-fixation in such an economically important species as maize, has still not been fully exploited. A preliminary approach to improve our understanding of the mechanisms controlling the establishment of such N2-fixing associations has been developed, using two maize inbred lines exhibiting different physiological characteristics. The bacterial-plant interaction has been characterized by means of a metabolomic approach. Two established model strains of Nif+ diazotrophic bacteria, Herbaspirillum seropedicae and Azospirillum brasilense and their Nif- couterparts defficient in nitrogenase activity, were used to evaluate the impact of the bacterial inoculation and of N2 fixation on the root and leaf metabolic profiles. The two N2-fixing bacteria have been used to inoculate two genetically distant maize lines (FV252 and FV2), already characterized for their contrasting physiological properties. Using a well-controlled gnotobiotic experimental system that allows inoculation of maize plants with the two diazotrophs in a N-free medium, we demonstrated that both maize lines were efficiently colonized by the two bacterial species. We also showed that in the early stages of plant development, both bacterial strains were able to reduce acetylene, suggesting that they contain functional nitrogenase activity and are able to efficiently fix atmospheric N2 (Fix+). The metabolomic approach allowed the identification of metabolites in the two maize lines that were representative of the N2 fixing plant-bacterial interaction, these included mannitol and to a lesser extend trehalose and isocitrate. Whilst other metabolites such as asparagine, although only exhibiting a small increase in maize roots following bacterial infection, were specific for the two Fix+ bacterial strains, in comparison to their Fix- counterparts. Moreover, a number

  6. Metabolic profiling of two maize (Zea mays L. inbred lines inoculated with the nitrogen fixing plant-interacting bacteria Herbaspirillum seropedicae and Azospirillum brasilense.

    Directory of Open Access Journals (Sweden)

    Liziane Cristina Brusamarello-Santos

    Full Text Available Maize roots can be colonized by free-living atmospheric nitrogen (N2-fixing bacteria (diazotrophs. However, the agronomic potential of non-symbiotic N2-fixation in such an economically important species as maize, has still not been fully exploited. A preliminary approach to improve our understanding of the mechanisms controlling the establishment of such N2-fixing associations has been developed, using two maize inbred lines exhibiting different physiological characteristics. The bacterial-plant interaction has been characterized by means of a metabolomic approach. Two established model strains of Nif+ diazotrophic bacteria, Herbaspirillum seropedicae and Azospirillum brasilense and their Nif- couterparts defficient in nitrogenase activity, were used to evaluate the impact of the bacterial inoculation and of N2 fixation on the root and leaf metabolic profiles. The two N2-fixing bacteria have been used to inoculate two genetically distant maize lines (FV252 and FV2, already characterized for their contrasting physiological properties. Using a well-controlled gnotobiotic experimental system that allows inoculation of maize plants with the two diazotrophs in a N-free medium, we demonstrated that both maize lines were efficiently colonized by the two bacterial species. We also showed that in the early stages of plant development, both bacterial strains were able to reduce acetylene, suggesting that they contain functional nitrogenase activity and are able to efficiently fix atmospheric N2 (Fix+. The metabolomic approach allowed the identification of metabolites in the two maize lines that were representative of the N2 fixing plant-bacterial interaction, these included mannitol and to a lesser extend trehalose and isocitrate. Whilst other metabolites such as asparagine, although only exhibiting a small increase in maize roots following bacterial infection, were specific for the two Fix+ bacterial strains, in comparison to their Fix- counterparts

  7. Metabolic profiling of two maize (Zea mays L.) inbred lines inoculated with the nitrogen fixing plant-interacting bacteria Herbaspirillum seropedicae and Azospirillum brasilense.

    Science.gov (United States)

    Brusamarello-Santos, Liziane Cristina; Gilard, Françoise; Brulé, Lenaïg; Quilleré, Isabelle; Gourion, Benjamin; Ratet, Pascal; Maltempi de Souza, Emanuel; Lea, Peter J; Hirel, Bertrand

    2017-01-01

    Maize roots can be colonized by free-living atmospheric nitrogen (N2)-fixing bacteria (diazotrophs). However, the agronomic potential of non-symbiotic N2-fixation in such an economically important species as maize, has still not been fully exploited. A preliminary approach to improve our understanding of the mechanisms controlling the establishment of such N2-fixing associations has been developed, using two maize inbred lines exhibiting different physiological characteristics. The bacterial-plant interaction has been characterized by means of a metabolomic approach. Two established model strains of Nif+ diazotrophic bacteria, Herbaspirillum seropedicae and Azospirillum brasilense and their Nif- couterparts defficient in nitrogenase activity, were used to evaluate the impact of the bacterial inoculation and of N2 fixation on the root and leaf metabolic profiles. The two N2-fixing bacteria have been used to inoculate two genetically distant maize lines (FV252 and FV2), already characterized for their contrasting physiological properties. Using a well-controlled gnotobiotic experimental system that allows inoculation of maize plants with the two diazotrophs in a N-free medium, we demonstrated that both maize lines were efficiently colonized by the two bacterial species. We also showed that in the early stages of plant development, both bacterial strains were able to reduce acetylene, suggesting that they contain functional nitrogenase activity and are able to efficiently fix atmospheric N2 (Fix+). The metabolomic approach allowed the identification of metabolites in the two maize lines that were representative of the N2 fixing plant-bacterial interaction, these included mannitol and to a lesser extend trehalose and isocitrate. Whilst other metabolites such as asparagine, although only exhibiting a small increase in maize roots following bacterial infection, were specific for the two Fix+ bacterial strains, in comparison to their Fix- counterparts. Moreover, a number

  8. Fontes de lipídeos na dieta de búfalas lactantes: consumo, digestibilidade e N-uréico plasmático Effects of dietary fat sources on intake, nutrient digestibility and plasma urea nitrogen for lactating water buffaloes

    Directory of Open Access Journals (Sweden)

    Ronaldo Lopes Oliveira

    2009-03-01

    Full Text Available Os efeitos da suplementação de fontes lipídicas sobre o consumo, a digestibilidade dos nutrientes e o N-uréico plasmático foram avaliados em 12 búfalas lactantes, em três quadrados latinos simultâneos, cada um com quatro animais, quatro períodos e quatro dietas contendo uma das fontes de lípideo estudadas (sem lipídeo adicional; grão de soja; óleo de soja ou caroço de algodão. O período experimental foi de 84 dias, com quatro períodos de 21 dias, divididos em 14 dias para a adaptação e 7 para coleta. A dieta foi fornecida à vontade, duas vezes ao dia, na forma de mistura completa. Nos dias de coleta de cada período, os alimentos fornecidos e as sobras foram pesados e amostrados para análise bromatológica. Amostras de fezes foram coletadas diretamente no reto dos animais para estimativa da produção de matéria seca fecal, utilizando-se a fibra em detergente neutro indigestível como indicador, e para o cálculo de digestibilidade aparente. Os consumos de matéria seca, proteína bruta, fibra em detergente neutro e fibra em detergente ácido foram semelhantes entre as dietas. Os consumos de extrato etéreo e nutrientes digestíveis totais (NDT foram maiores para a dieta com óleo de soja. Os coeficientes de digestibilidade de matéria seca, proteína bruta e carboidratos não-fibrosos e as concentrações de N-uréico plasmático foram semelhantes entre as dietas. A utilização das fontes de lipídeos nas dietas de búfalas em lactação não influenciou o consumo e coeficiente de digestibilidade da matéria seca. Entretanto, as digestibilidades do extrato etéreo da dieta com grão de soja e das frações fibrosas da dieta com caroço de algodão foram as mais baixas.The effects of fat sources on intake, nutrient digestibility and plasma urea nitrogen were evaluated in lactating water buffalo. Twelve females were randomly distributed into four treatments: without additional lipid, soybean grain, soybean oil and

  9. Microalgal Cultivation in Treating Liquid Digestate from Biogas Systems.

    Science.gov (United States)

    Xia, Ao; Murphy, Jerry D

    2016-04-01

    Biogas production via anaerobic digestion (AD) has rapidly developed in recent years. In addition to biogas, digestate is an important byproduct. Liquid digestate is the major fraction of digestate and may contain high levels of ammonia nitrogen. Traditional processing technologies (such as land application) require significant energy inputs and raise environmental risks (such as eutrophication). Alternatively, microalgae can efficiently remove the nutrients from digestate while producing high-value biomass that can be used for the production of biochemicals and biofuels. Both inorganic and organic carbon sources derived from biogas production can significantly improve microalgal production. Land requirement for microalgal cultivation is estimated as 3% of traditional direct land application of digestate. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Nitrogen metabolism in plants using 15N as tracer. Part of a coordinated programme on the use of isotopes in fertilizer efficiency studies on grain legumes

    International Nuclear Information System (INIS)

    Pate, J.; Atkins, C.

    1978-01-01

    Techniques are described for studying the economy of carbon and nitrogen in annual nodulated legumes. Budgets for utilization of net photosynthate are constructed for cowpea (Vigna unguiculata (L) Walp.) and white lupin (Lupinus albus L.), including expenditure in respiration and dry matter accumulation of plant parts, carbon consumption in growth, respiration and export of fixed nitrogen by nodules, and the provision of recent photosynthate and earlier-fixed carbon to fruits. Sources of nitrogen to fruits are defined, and efficiencies of conversion of net photosynthate to protein of above-ground vegetative parts and of seeds are computed. Consideration is given to the timing of events associated with loss of symbiotic activity after flowering. Literature giving estimates of the respiratory requirements of nitrogen fixation by nodules is reviewed. Rates of respiration of nodules of cowpea, white lupin and pea (Pisum sativum L.) are assessed from a theoretical viewpoint, basing the estimates on ATP requirements for assimilation of N 2 into nitrogenous solutes, and published values for respiration costs in plant tissues. Expressed as CO 2 output per unit of nitrogen assimilated, these estimates greatly exceed the experimentally-observed CO 2 efflux of nodules of the species. This discrepancy is examined in relation to the capacity of nodules to fix CO 2 and the uncertainty of the in vivo requirement of nitrogenase for ATP

  11. Molecular evidence for the coordination of nitrogen and carbon metabolisms, revealed by a study on the transcriptional regulation of the agl3EFG operon that encodes a putative carbohydrate transporter in Streptomyces coelicolor.

    Science.gov (United States)

    Cen, Xu-Feng; Wang, Jing-Zhi; Zhao, Guo-Ping; Wang, Ying; Wang, Jin

    2016-03-18

    In the agl3EFGXYZ operon (SCO7167-SCO7162, abbreviated as agl3 operon) of Streptomyces coelicolor M145, agl3EFG genes encode a putative ABC-type carbohydrate transporter. The transcription of this operon has been proved to be repressed by Agl3R (SCO7168), a neighboring GntR-family regulator, and this repression can be released by growth on poor carbon sources. Here in this study, we prove that the transcription of agl3 operon is also directly repressed by GlnR, a central regulator governing the nitrogen metabolism in S. coelicolor. The electrophoretic mobility shift assay (EMSA) employing the agl3 promoter and mixtures of purified recombinant GlnR and Agl3R indicates that GlnR and Agl3R bind to different DNA sequences within the promoter region of agl3 operon, which is further confirmed by the DNase I footprinting assay. As Agl3R and GlnR have been demonstrated to sense the extracellular carbon and nitrogen supplies, respectively, it is hypothesized that the transcription of agl3 operon is stringently governed by the availabilities of extracellular carbon and nitrogen sources. Consistent with the hypothesis, the agl3 operon is further found to be derepressed only under the condition of poor carbon and rich nitrogen supplies, when both regulators are inactivated. It is believed that activation of the expression of agl3 operon may facilitate the absorption of extracellular carbohydrates to balance the ratio of intracellular carbon to nitrogen. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Uncoupling of silicon compared with carbon and nitrogen metabolisms and the role of the cell cycle in continuous cultures of Thalassiosira pseudonana (Bacillariophyceae) under light, nitrogen and phosphorus control

    NARCIS (Netherlands)

    Claquin, P.; Martin-Jézéquel, V.R.; Kromkamp, J.C.; Veldhuis, M.; Kraay, G.W.

    2002-01-01

    The elemental composition and the cell cycle stages of the marine diatom Thalassiosira pseudonana Hasle and Heimdal were studied in continuous cultures over a range of different light- (E), nitrogen- (N), and phosphorus- (P) limited growth rates. In all growth conditions investigated, the decrease

  13. 76 FR 63313 - National Institute of Diabetes and Digestive and Kidney Diseases; Notice of Closed Meeting

    Science.gov (United States)

    2011-10-12

    ... Diabetes and Digestive and Kidney Diseases Special Emphasis Panel, Liver Cell Membrane Proteins. Date... Diabetes and Digestive and Kidney Diseases; Notice of Closed Meeting Pursuant to section 10(d) of the..., Diabetes, Endocrinology and Metabolic Research; 93.848, Digestive Diseases and Nutrition Research; 93.849...

  14. 77 FR 9671 - National Institute of Diabetes and Digestive and Kidney Diseases; Notice of Closed Meeting

    Science.gov (United States)

    2012-02-17

    ... Diabetes and Digestive and Kidney Diseases Special Emphasis Panel; Liver Tissue and Cell Distribution... Diabetes and Digestive and Kidney Diseases; Notice of Closed Meeting Pursuant to section 10(d) of the... Assistance Program Nos. 93.847, Diabetes, Endocrinology and Metabolic Research; 93.848, Digestive Diseases...

  15. 75 FR 38817 - National Institute of Diabetes and Digestive