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Essential Amino Acids (essential + amino_acids)
Selected AbstractsEssential amino acids, from LUCA to LUCYCOMPLEXITY, Issue 4 2008Vijayasarathy Srinivasan No abstract is available for this article. [source] Gel growth and characterization of , -DL-methionineCRYSTAL RESEARCH AND TECHNOLOGY, Issue 4 2006E. Ramachandran Abstract DL-Methionine [C5H11NO2S] is one of the essential amino acids in humans. It has two crystalline forms, viz., ,- and ,- methionine. In the present study, , - form is crystallized in silica gel; under suitable pH conditions by single diffusion method. The grown crystals were characterized by density measurement and single crystal X-ray diffraction. Fourier transform infrared (FTIR) spectroscopic studies, thermal analysis and scanning electron microscopic (SEM) studies were also made as part of the structural studies. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Separation of twenty underivatized essential amino acids by capillary zone electrophoresis with contactless conductivity detectionELECTROPHORESIS, Issue 4 2003Pavel Coufal Abstract Twenty underivatized essential amino acids were separated using capillary zone electrophoresis and consequently detected with contactless conductivity detection (CCD). A simple acidic background electrolyte (BGE) containing 2.3 M acetic acid and 0.1% w/w hydroxyethylcellulose (HEC) allowed the electrophoretic separation and sensitive detection of all 20 essential amino acids in their underivatized cationic form. The addition of HEC to the BGE suppressed both, electroosmotic flow and analyte adsorption on the capillary surface resulting in an excellent migration time reproducibility and a very good analyte peak symmetry. Additionally, the HEC addition significantly reduced the noise and long-term fluctuations of the CCD baseline. The optimized electrophoretic separation method together with the CCD was proved to be a powerful technique for determination of amino acid profiles in various natural samples, like beer, yeast, urine, saliva, and herb extracts. [source] Use of the oligochaete, Lumbriculus variegatus, as a prey organism for toxicant exposure of fish through the dietENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2006David R. Mount Abstract The oligochaete, Lumbriculus variegatus, has several characteristics that make it desirable as a prey organism for conducting dietary exposure studies with fish. We conducted 21- and 30-d experiments with young fathead minnows (Pimephales promelas) and rainbow trout (Oncorhynchus mykiss), respectively, to determine whether a diet consisting solely of L. variegatus would support normal growth and to compare performance with standard diets (Artemia nauplii, frozen brine shrimp, or trout chow). All diets were readily accepted, and fish survived and grew well. Food conversion in both fathead minnows and rainbow trout was as high as or higher for the oligochaete diet compared with others, although this comparison is influenced by differences in ration, ingestion rate, or both. The oligochaete diet had gross nutritional analysis similar to the other diets, and meets fish nutrition guidelines for protein and essential amino acids. Methodologies and practical considerations for successfully using oligochaetes as an experimental diet are discussed. Considering their ready acceptance by fish, their apparent nutritional sufficiency, the ease of culturing large numbers, and the ease with which they can be loaded with exogenous chemicals, we believe that L. variegatus represents an excellent choice of exposure vector for exposing fish to toxicants via the diet. [source] THE ROLE OF BACTERIAL SYMBIONTS IN AMINO ACID COMPOSITION OF BLACK BEAN APHIDSINSECT SCIENCE, Issue 3 2003Xue-xia Miao Abstract To evaluate the role of bacterial symbionts (Buchnera spp.) in the black bean aphids (Aphis craccivora Koch), the aphids were treated with the antibiotic, rifampicin, to eliminate their intracellular symbiotic bacteria. Analysis of protein and amino acid concentration in 7-day-old of aposymbiotic aphids showed that the total protein content per mg fresh weight was significantly reduced by 29%, but free amino acid titers were increased by 17%. The ratio of the essential amino acids was in general only around 20% essential amino acids in phloem sap of broad bean, whereas it was 44% and 37% in symbiotic and aposymbiotic aphids, respectively, suggesting that the composition of the free amino acids was unbalanced. For example, the essential amino acid, threonine represented 21.6% of essential amino acids in symbiotic aphids, but it was only 16.7% in aposymbiotic aphids. Likewise, two nonessential amino acids, tyrosine and serine, represented 8.9% and 5.6% of total amino acids in symbiontic aphids, respectively, but they enhanced to 21.1% and 13.6% in aposymbiotic aphids. It seems likely that the elevated free amino acid concentration in aposymbiotic aphids was caused by the limited protein anabolism as the result of the unbalanced amino acid composition. [source] Chemical composition and toxic trace element composition of some Nigerian edible wild mushroomsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2008Olumuyiwa S. Falade Summary Two essential amino acids (methionine and tryptophan); anti-nutritional factors (tannin and trypsin inhibitor) and toxic elements (Pb, Cd, Ni, As, Hg and Cr) were determined spectrophotometrically from five edible wild mushrooms. The tryptophan content was between 1.00 and 1.82 g (100 g),1 but methionine was low at 0.26,1.38 g (100 g),1. Tannin content was high (30.3,40.0 mg g,1) but trypsin inhibitor was low (22.0,39.5 TIU g,1). Trace elements analysis reviled Pb (0.34,5.06 mg kg,1) to be the highest of all the trace elements. Cd was (0.06,1.70 mg kg,1), Ni (0.26,2.08 mg kg,1), As (0.17,0.92 mg kg,1), Hg (0.01,0.05 mg kg,1) and Cr (0.04,0.22 mg kg,1). These mushrooms are nutritious but must be well processed to eliminate or at least reduce the levels of tannin and Pb to improve their nutritional values. [source] Impact of dietary crude protein and amino acids status on performance and some excreta characteristics of broiler chicks during 10,28 days of ageJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3 2010N. F. Namroud Summary A study was conducted in a completely randomised design to evaluate the effects of providing almost all important essential amino acids (EAA) in low-crude protein (CP) diets equal to that of higher CP diets in broiler chickens. Also the effects of additional mixture of glycine (Gly) and glutamic acid (Glu) or supplementation of excess EAA to low-CP diets on the live performance and excreta characteristics including pH, moisture, nitrogen, uric acid and ammonia concentration were measured to ascertain the optimum CP concentration for the maximum performance and reduced excreta ammonia concentration. Male, broiler chickens growing from 10 to 28 days of age were fed eight experimental diets. Reducing dietary CP below 19% negatively affected performance. Adding the Gly and Glu mixtures to 17% CP diets improved live performance. Reducing CP to 19% with a normal amino acids status declined N, ammonia, uric acid, moisture and pH of excreta significantly. These findings suggest that diminishing dietary CP from 23% to 19% while maintaining adequate EAA levels during 10,28 days of age results in not only a significant decline in N emission, but also a probable reduction in the NH3 volatilisation because of reduction in pH and moisture. Contrary to expectations, reduction of dietary CP below the minimum level (19%) resulted in more ammonia. All these factors may improve on litter and air quality within the housing facility and reduce the ventilation rate required to emit the elevated ammonia gas concentrations. [source] Effects of rumen-protected methionine in a low protein ration on metabolic traits and performance of early lactating cows as opposed to rations with elevated crude protein contentJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 5 2000T. F. Kröber Summary A 5-week experiment with 24 multiparous early lactating Brown Swiss cows was conducted to investigate the effects of supplementary rumen-protected methionine in conjunction with dietary protein reduction on metabolism and performance after 1 week of control measurement. Three rations containing 175, 150 and 125 g of crude protein/kg feed dry matter were supplemented with methionine. The fourth ration, also only containing 125 g of crude protein/kg dry matter, remained unsupplemented. The four treatment groups had a similar metabolic supply of other essential amino acids, protein and energy, as calculated by various approaches. The two low protein rations were, however, slightly deficient in ruminally degraded protein. Treatment effects remained low on feed intake, forage meal pattern, milk yield and fat as well as lactose content. In contrast, the content and yield of milk protein significantly declined only in the unsupplemented low protein ration relative to the initial value. Compared with this ration, the decline in milk protein yield was clearly delayed in the supplemented low protein ration. Blood plasma methionine tended to be reduced without supplementation and to be increased with additional methionine. Supplementation of methionine reduced other plasma amino acids. Plasma insulin, glucose, lactate, ketone bodies and aspartate amino transferase activity indicated a certain liver stress and a somewhat elevated energy requirement with high and particularly with low protein content (when unsupplemented). Methionine improved metabolic protein utilization, followed by the lowest plasma, urine and milk urea levels in the supplemented low protein diet. In conclusion, no major adverse effects were assessed under the conditions tested. Supplementation of methionine may nevertheless be useful in rations with particularly low protein content fed to early lactating cows in order to prevent negative long-term effects which were only visible here as trends. Zusammenfassung Auswirkungen von pansengeschütztem Methionin in einer Niedrigproteinration im Vergleich zu Rationen mit erhöhtem Rohproteingehalt auf Stoffwechselmerkmale und Leistung von frischlaktierenden Milchkühen In einem fünfwöchigen Experiment mit 24 frischlaktierenden Braunviehkühen wurden die Auswirkungen einer Ergänzung mit pansengeschütztem Methionin bei gleichzeitiger Reduktion der Proteinzufuhr nach einer einwöchigen Kontrollphase geprüft. Drei Rationen mit 175, 150 und 125 g Rohprotein/kg T wurden mit Methionin ergänzt. Eine weitere Variante, ebenfalls nur mit 125 g Rohprotein/kg T, wurde nicht supplementiert. Die vier Varianten stellten gemäß verschiedener Futterbewertungsysteme eine vergleichbare metabolische Versorgung mit den übrigen essentiellen Aminosäuren, Protein und Energie sicher. Die Niedrigproteinvarianten enthielten allerdings etwas zu wenig pansenabbaubares Protein. Futteraufnahme, Muster des Grundfutterverzehrs, Milchleistung sowie Fett-und Laktosegehalt der Milch zeigten nur geringe Reaktion auf die Behandlungen. Milchproteingehalt und -menge waren nur in der nicht ergänzten Niedrigproteinvariante relativ zum Ausgangswert signifikant verringert. Im Vergleich zur unsupplementierten Niedrigproteinration war dagegen der Abfall mit Ergänzung deutlich verzögert. Gegenüber dem Ausgangswert war die Methioninkonzentration im Blutplasma ohne Ergänzung tendenziell erniedrigt, mit Ergänzung erhöht. Es erfolgte eine Verringerung der Plasmakonzentration anderer Aminosäuren durch die Methioninergänzung der Niedrigproteinration. Die Plasmaniveaus von Insulin, Glucose, Laktat, Ketonkörpern und Aspartataminotransferase-Aktivität lassen auf eine gewisse Leberbelastung und einen etwas höheren Energiebedarf mit hohem und besonders mit niedrigem Proteingehalt (unsupplementiert) schließen. Die Zulage an Methionin verbesserte die metabolische Proteinverwertung, so dass die Harnstoffgehalte in Blut, Milch und Harn in dieser Niedrigproteinvariante am niedrigsten waren. Insgesamt ergaben sich keine grösseren ungünstigen Effekte unter den getesteten Bedingungen. Dennoch könnte die Ergänzung von Rationen mit besonders niedrigem Rohproteingehalt mit Methionin beim Einsatz an frischlaktierende Kühe hilfreich sein, um negative Langzeitwirkungen zu verhindern, die sich hier lediglich andeuteten. [source] Negative effects of the amino acids Lys, His, and Thr on S6K1 phosphorylation in mammary epithelial cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 4 2008Rotem Ladovsky Prizant Abstract The role of essential amino acids (AA) on protein synthesis via the mTOR pathway was studied in murine mammary epithelial cells cultured under lactogenic conditions. Leu, Ile, and Val increased S6K1 phosphorylation compared to that measured in AA-deprived cells. Trp, Phe, and Met had no effect. Surprisingly, Lys, His, and Thr inhibited S6K1 phosphorylation in both murine and bovine mammary cells. Thr exhibited the most potent inhibition, being the only amino acid that competed with Leu's positive role. In non-deprived cells, there was no observable effect of Lys, His, or Thr on S6K1 phosphorylation at concentrations up to five times those in the medium. However, their addition as a mix revealed a synergistic negative effect. Supplementation of Lys, His, and Thr abrogated mTOR Ser 2448 phosphorylation, with no effect on Akt Ser 473,an mTORC2 target. This confirms specific mTORC1 regulation of S6K1 phosphorylation. The individual supplementation of Lys, His, and Thr maintained a low level of IRS-1 phosphorylation, which was dose-dependently increased by their combined addition. Thus, in parallel to inhibiting S6K1 activity, these AA may act synergistically to activate an additional kinase, phosphorylating IRS-1 via an S6K1-independent pathway. In cultures supplemented by Lys, His, and Thr, cellular protein synthesis decreased by up to 65%. A more pronounced effect was observed on ,-casein synthesis. These findings indicate that positive and negative signaling from AA to the mTOR pathway, combined with modulation of insulin sensitization, mediate the synthesis rates of total and specific milk proteins in mammary epithelial cells. J. Cell. Biochem. 105: 1038,1047, 2008. © 2008 Wiley-Liss, Inc. [source] Chitin production by Lactobacillus fermentation of shrimp biowaste in a drum reactor and its chemical conversion to chitosanJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 9 2005Mukku Shrinivas Rao Abstract Chitin was produced by fermenting shrimp heads and shells with Lactobacillus plantarum 541 in a drum reactor with an internal volume of 3 dm3. The crude chitin yield from heads and shells was 4.5 and 13% respectively, comparable to the values obtained by the chemical method. For shrimp heads 83% deproteination and 88% demineralisation and for shrimp shells 66% deproteination and 63% demineralisation were achieved. The liquor obtained in both cases was of good sensory quality with a high content of essential amino acids and therefore with potential to produce protein powder for human consumption. The crude chitin was refined and converted to chitosan using 12.5 M NaOH. The chitosan obtained had a residual ash and protein content below 1%, a solubility of more than 98%, a viscosity in the range 50,400 cP and a degree of deacetylation of 81,84%. The molecular weight was in the range (0.8,1.4) × 106 Da. IR analysis indicated that the chitosan obtained through fermentation was similar to that obtained by the chemical method. Copyright © 2005 Society of Chemical Industry [source] AMINO ACID COMPOSITION OF SOME BRAZILIAN SEAWEED SPECIESJOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2000MÁRCIO VIANA RAMOS Fourteen common seaweed species from northeastern Brazil were examined for protein content and amino acid composition. Protein content varied greatly among the species, ranging from 2.30% (dry weight basis) in Corallina offlcinalis to 25.60%, in Amansia multifida. The species Amansia multifida, Caulerpa sertularioides. Enantiocladia dupcrreyi, Solieria filiformis and Vidalia obtusiloba had protein levels comparable to those of many edible legume seeds, above 18%. They showed high levels of acidic amino acids and reasonable levels of essential amino acids, with methionine being the first limiting amino acid for most of the species. The exceptions were Sargassum vulgare that had a very high content of methionine and Caulerpa sertularioides in which lysine is the first limiting amino acid and methionine the second limiting one. All species are rich in phenylalanine/tyrosine and threonine, and six are very good sources of lysine. The potential use of these species as food and/or feed is discussed. [source] THE POTENTIAL OF TERMINALIA CATAPPA (TROPICAL ALMOND) SEED AS A SOURCE OF DIETARY PROTEINJOURNAL OF FOOD QUALITY, Issue 3 2004C.A. EZEOKONKWO ABSTRACT The nutritional value of Terminalia catappa seed as a source of dietary protein was investigated. The crude protein content of the seed was high (25.81%). The amino acid analysis showed a good pattern of the essential amino acids (EAA) (in g/16 g N) - leucine (7.32), isoleucine (3.58), valine (2.74), phenylalanine (3.04), tryptophan (0.9), methionine (1.48), lysine (3.39), threonine (2.94), histidine (2.96). Tyrosine (2.12) is the limiting amino acid. The protein quality of the seed was evaluated by in vivo bioassays using weanling male Sprague Dawley rats (50,60 g). The indices of protein quality measured include PER, BV, NPU and TD. There were positive correlation between PER and BV (r = 0.7105), PER and body weight gain (r = 0.9157), PER and nitrogen intake (r = 0.7428). The results showed that T. catappa seed protein has a good pattern of the EAA, is highly digestible, can support growth and positive nitrogen balance and thus has a high dietary protein quality. [source] Amino Acid and Mineral Composition of Protein and Other Components and Their Recovery Yields from Whole Antarctic Krill (Euphausia superba) Using Isoelectric Solubilization/PrecipitationJOURNAL OF FOOD SCIENCE, Issue 2 2009Y.-C. Chen ABSTRACT:, Proteins and insolubles were recovered from whole Antarctic krill via novel isoelectric solubilization/precipitation using different pH treatments. The protein recovery yield was 45% to 50% (dry basis). The recovered proteins had higher (P < 0.05) content of essential amino acids (EAAs) and non-EAAs as well as higher (P < 0.05) ratio of total EAA/total AA than whole krill. The EAAs constituted almost 50% of total AAs. The least extreme pH treatments (pHs 3 and 12) yielded highest (P < 0.05) content of EAAs. The quality of recovered proteins was high based on EAAs meeting FAO/WHO/UNU recommendations for adults and infants. The basic pH yielded proteins with the lowest (P < 0.05) amount of minerals and the highest (P < 0.05) amount of Ca, P, and Mg in the insolubles when compared to the acidic treatments. However, both basic and acidic treatments effectively removed minerals from recovered proteins without the removal of the exoskeleton before processing. Therefore, besides high-quality proteins, the insolubles may provide a mineral supplement in the animal diet. [source] Amino Acid, Fatty Acid, and Mineral Profiles of Materials Recovered from Rainbow Trout (Oncorhynchus mykiss) Processing By-Products Using Isoelectric Solubilization/PrecipitationJOURNAL OF FOOD SCIENCE, Issue 9 2007Y.-C. Chen ABSTRACT:, Protein, lipid, and insolubles (bones, skin, scales, fins, insoluble protein, and more) were recovered from rainbow trout processing by-products by means of isoelectric solubilization/precipitation at basic pH and acidic pH. Isoelectric solubilization/precipitation of the trout processing by-products resulted in the recovery of protein that was higher (P < 0.05) in essential amino acids (EAAs), non-EAAs, and total EAA/total AA ratio when compared to the processing by-products. Basic pH treatments yielded a higher (P < 0.05) content of EAAs than the acidic pH treatments. Nutritional quality of the recovered protein was high based on EAAs meeting the FAO/WHO/UNU recommendations for adults. The presence of omega-3 and omega-6 fatty acids (,-3, ,-6 FAs) and the ,-3/,-6 ratio in the recovered lipids were similar to the trout processing by-products, indicating that the pH treatments had no effect on these FAs. Ca and P contents of the processing by-products exceeded the recommended dietary allowances (RDA), but Fe and Mg did not. Basic pH treatments yielded protein with the lowest (P < 0.05) amount of minerals and the highest (P < 0.05) amount of Ca, P, and Mg in the insolubles when compared to acidic pH. The isoelectric solubilization/precipitation of the processing by-products effectively removed minerals from the recovered protein without removal of the bones, skin, scales, fins, and so on, prior to processing. The results indicated that isoelectric solubilization/precipitation, particularly at basic pH, permitted recovery of high-quality protein and lipids from fish processing by-products for human food uses; also, the recovered insolubles may be used in animal feeds as a source of minerals. [source] Identification of single amino acid residues essential for the binding of lipopolysaccharide (LPS) to LPS binding protein (LBP) residues 86,99 by using an Ala-scanning libraryJOURNAL OF PEPTIDE SCIENCE, Issue 4 2002Dr O. Reyes Abstract Lipopolysaccharide binding protein (LBP) is a 60 kDa acute phase glycoprotein capable of binding to LPS of Gram-negative bacteria and facilitating its interaction with cellular receptors. This process is thought to be of great importance in systemic inflammatory reactions such as septic shock. A peptide corresponding to residues 86,99 of human LBP (LBP86,99) has been reported to bind specifically with high affinity the lipid A moiety of LPS and to inhibit the interaction of LPS with LBP. We identified essential amino acids in LBP86,99 for binding to LPS by using a peptide library corresponding to the Ala-scanning of human LBP residues 86,99. Amino acids Trp91 and Lys92 were indispensable for peptide,LPS interaction and inhibition of LBP,LPS binding. In addition, several alanine-substituted synthetic LBP-derived peptides inhibited LPS,LBP interaction. Substitution of amino acids Arg94, Lys95 and Phe98 by Ala increased the inhibitory effect. The mutant Lys95 was the most active in blocking LPS binding to LBP. These findings emphasize the importance of single amino acids in the LPS binding capacity of small peptides and may contribute to the development of new drugs for use in the treatment of Gram-negative bacterial sepsis. Copyright © 2002 European Peptide Society and John Wiley & Sons, Ltd. [source] Estimating Amino Acid Requirement of Brazilian Freshwater Fish from Muscle Amino Acid ProfileJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 6 2009ÁLvaro José De Almeida Bicudo Information on nutritional requirement of some Brazilian farmed fish species, especially essential amino acids (EAA) requirements, is scarce. The estimation of amino acids requirements based on amino acid composition of fish is a fast and reliable alternative. Matrinxa, Brycon amazonicus, and curimbata, Prochilodus lineatus, are two important Brazilian fish with potential for aquaculture. The objective of the present study was to estimate amino acid requirements of these species and analyze similarities among amino acid composition of different fish species by cluster analysis. To estimate amino acid requirement, the following formula was used: amino acid requirement = [(amount of an individual amino acid in fish muscle tissue) × (average totalEAA requirement among channel catfish, Ictalurus punctatus, Nile tilapia, Oreochromis niloticus, and common carp, Cyprinus carpio)]/(average fish muscle totalEAA). Most values found lie within the range of requirements determined for other omnivorous fish species, in exception of leucine requirement estimated for both species, and arginine requirement estimated for matrinxa alone. Rather than writing off the need for regular dose,response assays under the ideal protein concept to determine EAA requirements of curimbata and matrinxa, results set solid base for the study of tropical species dietary amino acids requirements. [source] Tail Muscle Free Amino Acid Concentration of Pacific White Shrimp, Litopenaeus vannamei, Fed Diets Containing Protein-bound versus Crystalline Amino AcidsJOURNAL OF THE WORLD AQUACULTURE SOCIETY, Issue 2 2009Joe M. Fox Tail muscle tissue free amino acids (FAA) concentration is reported for subadult (4.3 g) Litopenaeus vannamei fed diets containing only protein-bound amino acids, crystalline lysine as a supplement to protein-bound lysine, and only crystalline amino acids (CAA). FAA were determined in shrimp at 0.00, 0.25, 0.5, 1, 2, 4, and 8 h postfeeding. Highest total tissue concentrations of essential amino acids and individual amino acids were typically observed 4 h postfeeding for shrimp fed intact and crystalline lysine-supplemented feeds. Those shrimp offered diets containing only CAA showed no tissue maxima. Similar uptake patterns for lysine shown by shrimp fed the intact and crystalline lysine-supplemented diet indicate the potential use of small amounts of crystalline lysine in shrimp feeds. [source] Assessment of protein nutritional quality and effects of traditional processes: A comparison between Ethiopian quality protein maize and five Ethiopian adapted normal maize cultivarsMOLECULAR NUTRITION & FOOD RESEARCH (FORMERLY NAHRUNG/FOOD), Issue 4 2003Habtamu Fufa Abstract The present study was designed to quantitatively measure and compare the levels and variations of total protein, individual amino acids, and computed protein efficiency ratio (C-PER) in raw and traditionally processed products of one recently released quality protein maize (QPM BH542) with four high-yield maize hybrids, namely flint BH660, semi-dent BH140, Pioneer 30H83, and Pioneer 30G97, as well as one local maize cultivar. The total protein content was variable among the cultivars ranging from 7% for BH660 to 8.6% for Pioneer 30H83, 8.9% for BH140, 9.8% for QPM BH542, 10.1% for local maize cultivar, and 11.8% for Pioneer 30G97, respectively. However, the QPM BH542 maize protein proved to be higher in nutritional quality than common maize proteins because it contained 30% to 82% more lysine, higher levels of arginine, tryptophan, histidine, threonine, cysteine, and valine. As a result, the QPM BH542 amino acid profile gives a good balance of total essential amino acids, limited only in lysine, and has a C-PER ratio of 2.2 compared to 1.14, 1.2, 1.4, 1.66, and 1.67 for Pioneer 30G97, local, BH-140, BH660, and Pioneer 30H83, respectively. The various traditional processes of maize have no significant effect on the protein nutritional quality of the new quality protein maize. Hence, the widely dissemination of it in agricultural cultivation as well as consumption by the general population is recommended. [source] Molecular physiology of adventitious root formation in Petunia hybrida cuttings: involvement of wound response and primary metabolismNEW PHYTOLOGIST, Issue 3 2009Amir H. Ahkami Summary ,,Adventitious root formation (ARF) in the model plant Petunia hybrida cv. Mitchell has been analysed in terms of anatomy, gene expression, enzymatic activities and levels of metabolites. This study focuses on the involvement of wound response and primary metabolism. ,,Microscopic techniques were complemented with targeted transcript, enzyme and metabolite profiling using real time polymerase chain reaction (PCR), Northern blot, enzymatic assays, chromatography and mass spectrometry. ,,Three days after severance from the stock plants, first meristematic cells appeared which further developed into root primordia and finally adventitious roots. Excision of cuttings led to a fast and transient increase in the wound-hormone jasmonic acid, followed by the expression of jasmonate-regulated genes such as cell wall invertase. Analysis of soluble and insoluble carbohydrates showed a continuous accumulation during ARF. A broad metabolite profiling revealed a strong increase in organic acids and resynthesis of essential amino acids. ,,Substantial changes in enzyme activities and metabolite levels indicate that specific enzymes and metabolites might play a crucial role during ARF. Three metabolic phases could be defined: (i) sink establishment phase characterized by apoplastic unloading of sucrose and being probably mediated by jasmonates; (ii) recovery phase; and (iii) maintenance phase, in which a symplastic unloading occurs. [source] Nutritional and Physiologic Significance of ,-Lactalbumin in InfantsNUTRITION REVIEWS, Issue 9 2003Bo Lönnerdal PhD ,-Lactalbumin is the major protein in breast milk (20 -25% of total protein) and has been described to have several physiologic functions in the neonatal period. In the mammary gland, it participates in lactose synthesis, thereby creating an osmotic "drag" to facilitate milk production and secretion. ,-Lactalbumin binds divalent cations (Ca, Zn) and may facilitate the absorption of essential minerals, and it provides a well-balanced supply of essential amino acids to the growing infant. During its digestion, peptides appear to be transiently formed that have antibacterial and immunostimulatory properties, thereby possibly aiding in the protection against infection. A novel folding variant ("molten globule state") of multimeric ,-lactalbumin has recently been discovered that has anti-infective activity and enhances apoptosis, thus possibly affecting mucosal cell turnover and proliferation. Cow milk also contains ,-lactalbumin, albeit less than human milk (2-5% of total protein in bovine milk), and protein fractions enriched with ,-lactalbumin may now be added to infant formula to provide some of the benefits of human ,-lactalbumin. [source] Amino acid budgets in three aphid species using the same host plantPHYSIOLOGICAL ENTOMOLOGY, Issue 3 2001J. P. Sandström Abstract. Nutrient provisioning in aphids depends both on the composition of ingested phloem sap and on the biosynthetic capabilities of the aphid and its intracellular symbionts. Amino acid budgets for three aphid species, Rhopalosiphum padi (L.), Schizaphis graminum (Rondani) and Diuraphis noxia (Mordvilko), were compared on a single host plant species, wheat Triticum aestivum L. Ingestion of amino acids from phloem, elimination of amino acids in honeydew, and the content of amino acids in aphids tissue were measured. From these values, ingestion rates were estimated and compared to honeydew and to estimated composition of aphid proteins. Ingestion rate was lowest in D. noxia due to low growth rate and low honeydew production; intermediate in S. graminum due to higher growth rate and intermediate honeydew production; and highest in R. padi, which had the highest rates for both variables. Both D. noxia and S. graminum induced increases in the amino acid content of ingested phloem. These changes in phloem content, combined with differences in ingestion rates, resulted in large differences among aphids in estimated rates of ingestion of individual amino acids. In honeydew, most essential amino acids were found in low amounts compared with the amounts ingested, especially for methionine and lysine. A few amino acids (arginine, cystine, histidine and tryptophan) were more abundant in honeydew of some aphids, suggesting oversupply. Aphid species differed in the composition of free amino acids in tissue but showed very similar composition in protein, implying similar requirements among the aphids. In R. padi and D. noxia, most essential amino acids were ingested in amounts insufficient for growth, implying dependence on symbiont provisioning. In S. graminum, most amino acids were ingested in amounts apparently sufficient for growth. [source] Study on bioactive compounds of in vitro cultured Calculus Suis and natural Calculus Bovis1ANIMAL SCIENCE JOURNAL, Issue 6 2009Tien-Chun WAN ABSTRACT The purpose of the study was to investigate bioactive compounds of in vitro cultured Calculus Suis and natural Calculus Bovis obtained as valuable by-products from animals used for meat production. The results showed that the components of natural Calculus Bovis were rich in bilirubin and biliverdin and had higher content of essential amino acids. The major amino acids of in vitro cultured Calculus Suis were identified as glycine, alanine, glutamic acid and aspartic acid, and those for natural Calculus Bovis were found to be glutamic acid, aspartic acid, proline, and arginine. The methionine and cysteine contents of precursors for glutathione in natural Calculus Bovis were significantly higher than those of in vitro cultured Calculus Suis. The mineral contents of zinc, iron and manganese of natural Calculus Bovis were significantly higher than those of in vitro cultured Calculus Suis. The major bile acids in both products were cholic acid and dehydrocholic acid, respectively. The chenodeoxycholic and ursodeoxycholic acid content of in vitro cultured Calculus Suis was significantly higher than that of natural Calculus Bovis. [source] Digestive proteinases and peptidases in the hepatopancreas of the southern brown shrimp (Farfantepenaeus subtilis) in two sub-adult stagesAQUACULTURE NUTRITION, Issue 4 2010D.S. BUARQUE Abstract The aim of this study was to examine proteinases and peptidases from the hepatopancreas of two sub-adult stages of Farfantepenaeus subtilis: SAS6 (5.93 ± 0.69 g wet weight) and SAS13 (13.26 ± 0.60 g wet weight). Trypsin and chymotrypsin activity was higher in the extract from the SAS6 individuals (P < 0.05). The highest activity among aminoacyl-,-naphthylamide substrates was found using alanine-, arginine-, leucine- and lysine-,-naphthylamide. There was a positive correlation between the recommended concentration of essential amino acids in penaeid shrimp feed and aminopeptidase activity in both sub-adult stages. Proteolytic activity of F. subtilis was strongly inhibited by specific trypsin inhibitors. The optimal temperature for trypsin, chymotrypsin and leucine aminopeptidase activity was between 45 and 55 °C. Six and seven bands were found in caseinolytic zymograms for SAS6 and SAS13 respectively. All bands were inhibited by phenylmethylsulfonyl fluoride in both sub-adult stages. The use of tosyl-lysine-chloromethyl-ketone and benzamidine caused strong inhibition of the proteolytic bands. Trypsin and chymotrypsin activity was the main difference observed between the protease pattern of SAS6 and SAS13F. subtilis. [source] Evaluation of indigenous marine periphytic Amphora, Navicula and Cymbella grown on substrate as feed supplement in Penaeus monodon postlarval hatchery systemAQUACULTURE NUTRITION, Issue 2 2009H. KHATOON Abstract Three isolated marine diatoms (Amphora, Navicula and Cymbella) grown on substrate were evaluated as feed supplement for Penaeus monodon postlarvae (PL) in hatchery system for a period of 19 days without changing water. Specific growth rate (day,1) (0.27 ± 0.0) and survival (%) (56.3 ± 1.8) of PLs were significantly higher (P < 0.05) in treatment tanks when compared with the control (0.20 ± 0.0; 36.0 ± 1.5, respectively). Shrimp PLs reared in substrate-based tanks had significantly higher (P < 0.05) levels of protein, lipid (521.0 ± 7.0; 304.0 ± 2 g kg,1 dry weight, respectively), ecosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) (189.0 ± 2.0; 176.0 ± 2 g kg,1 of total fatty acid, respectively) than the control (435.0 ± 22.0; 258.0 ± 22 g kg,1 dry weight; 172.0 ± 5.0; 152 ± 2 g kg,1 total fatty acid, respectively). The periphytic diatoms contained protein and lipid (430,490; 230,260 g kg,1 dry weight, respectively), EPA (30,150 g kg,1 of total fatty acids), DHA (20,30 g kg,1 of total fatty acids) and nine essential amino acids. The results showed that isolated marine periphytic diatoms grown on substrate could be used as feed supplement in enhancing the growth and survival of P. monodon postlarvae. [source] Amino acid composition of Arctic charr, Salvelinus alpinus (L.) and the prediction of dietary requirements for essential amino acidsAQUACULTURE NUTRITION, Issue 4 2007R. GURURE Abstract Embryo somatic tissues, non-somatic yolk-sac materials, and whole, individual fingerlings (age 0+) of Arctic charr, Salvelinus alpinus (L.), as well as a commercial trout diet, were analysed for a wide spectrum of amino acids. Analytical material consisted of prefeeding swim-up fry that were separated into discrete yolk sac and somatic embryo tissue samples. Amino acid concentrations in fry somatic tissue and whole fingerlings were generally very similar to each other, but were lower than those measured in yolk materials. Higher correlations were observed between the majority of specific amino acid concentrations in the trout diet when compared with fingerling data (r2 = 0.91) and fry somatic tissue data (r2 = 0.89), than when correlated with fry yolk sac material (r2 = 0.76). These results indicate that the essential amino acid profiles of fry somatic tissue and whole fingerlings are closer to that of a commercial feed than they are to the endogenous profiles found in the embryonic yolk sac material itself. The dietary ratios of individual essential amino acids were also compared with the total essential amino acid concentrations (A/E ratios) in whole fingerling tissues, and these ratios could be used to accurately estimate the apparent essential amino acid requirements of Arctic charr. The rationale for using carcass amino acid composition data to estimate the dietary essential amino acid requirements of Arctic charr is discussed. [source] Digestive peptidases and proteinases in the midgut gland of the pink shrimp Farfantepenaeus paulensis (Crustacea, Decapoda, Penaeidae)AQUACULTURE RESEARCH, Issue 7 2009Diego Souza Buarque Abstract Proteases from the midgut gland of the Farfantepenaeus paulensis juveniles were assessed. Enzyme activity was determined using protease substrates and inhibitors. The effect of pH, temperature and calcium on proteolytic activity was assayed. Caseinolytic activity was analysed in substrate-sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Trypsin, chymotrypsin and leucine aminopeptidase activity was detected. Proteolytic activity was strongly inhibited by the specific trypsin inhibitors. Tosyl-phenylalanine chloromethyl ketone inhibited 59.3% of chymotrypsin activity. The greatest trypsin-like activity occurred at pH 8.0 and 45 °C. Chymotrypsin-like activity reached maximal values at alkaline pH (7.2,9.0) and 55 °C. CaCl2 did not increase trypsin-like activity, but rather inhibited it at concentrations of 30 (20%), 50 (30%) and 100 mM (50%). The substrate-SDS-PAGE zymogram revealed eight proteinase bands. Two possibly thermal-resistant (85 °C, 30 min) chymotrypsin isoforms were found, which were inhibited by phenyl-methyl-sulphonyl-fluoride. Aminopeptidase activity of enzyme extracts (Arg, Leu, Lys, Phe and Val) and the recommended concentrations of these essential amino acids in penaeid shrimp diets were positively correlated (P<0.05). Beause protein digestion involves the combined action of different enzymes, adequate knowledge of shrimp digestion and enzyme characteristics is required for the assessment of the digestive potential of different feed sources and development of in vitro digestibility protocols. [source] Nutritional values of Apocyclops dengizicus (Copepoda: Cyclopoida) fed Chaetocerous calcitrans and Tetraselmis tetratheleAQUACULTURE RESEARCH, Issue 1 2008Omidvar Farhadian Abstract The cyclopoid copepod Apocyclops dengizicus was isolated from a marine shrimp pond, Penaeus monodon, Kuala Selangor, Malaysia, and reared in the laboratory for 3 months to establish a pure population stock. Amino acids and fatty acids of A. dengizicus were determined when fed Chaetocerous calcitrans (C), Tetraselmis tetrathele (T) and their combination (CT) (1:1 by number). The protein contents in A. dengizicus that received C, T and CT were 46.8%, 60.5% and 55.3% of dry weight respectively. Correspondingly, the lipid was 19.0%, 17.8% and 19.1% of dry weight for C, T and CT respectively. The A. dengizicus cultured on C, T and CT had total essential amino acids without tryptophan measurement of 57.1, 60.3 and 67.8 and total non-essential amino acids of 42.9%, 40.0% and 32.2% of total amino acids. The fatty acid content of A. dengizicus showed that it was able to synthesize docosahexenoic acid (22:6n-3, DHA), eicosapentaenoic acid (20:5n-3, EPA) and arachidonic acid (20: 4n-6, ARA) from examined microalgal diets. The DHA:EPA:ARA ratios of A. dengizicus fed on C, T and CT were 6.8:3.0:1, 14.0:5.8:1 and 11.6:2.6:1 respectively. Apocyclops dengizicus could be suitable live food for larval fish and shrimp rearing because it meets their nutritive requirements. [source] Biochemical and technical observations supporting the use of copepods as live feed organisms in marine larvicultureAQUACULTURE RESEARCH, Issue 8 2006Guillaume Drillet Abstract The use of live prey is still necessary for a large number of raised fish species. Small sized rotifers are usually used as live preys during the first days of feeding in small mouth fish. An alternative to this is the use of copepods as prey for first feeding. In this study, the sizes, weight and biochemical contents of two copepods and one rotifer species raised on similar algal food conditions were compared. Rotifers contained a higher proportion of essential amino acids in the free amino acid (FAA) fraction (43%) than copepods (30,32%). However, rotifers had lower levels of important fatty acids like DHA (7% compared with 23,32% in copepods) and their DHA/EPA ratio was lower than that in copepods (0.54 compared with 1.35,1.63 in copepods). The FAA pattern of the preys tended to be species-specific and its implications from an aquaculture point of view is discussed. In contrast, the-protein bound amino acids tended to be very conservative among the studied organisms. The second part of the work is focused on ,the price' of hatching in Acartia tonsa eggs before or after cold storage at 3°C. The fatty acid contents in A. tonsa tended to decrease with the storage time. It also decreased with hatching of the nauplii, but its proportion compared with the dry weight remained constant. [source] Assessment of requirement values for essential amino acids in the prawn, Marsupenaeus japonicus (Bate)AQUACULTURE RESEARCH, Issue 6 2002S Teshima Abstract The requirements of juvenile prawn, Marsupenaeus japonicus (Bate), 0.79 g initial body weight, for essential amino acids (EAA) were evaluated based on the daily increase of each EAA in the whole body when the prawn was maintained on a diet with a high nutritive value (a casein-squid protein-based diet). The quantities of each EAA needed daily for growth and maintenance of prawn are conceived to correspond to the daily requirements of this prawn species for EAA. Therefore, these requirement values of respective EAA should be supplied from dietary proteins. To determine these values, protein and amino acids of the whole body of the prawn were quantified before and after feeding experiments, and the quantities of respective EAA needed to meet the requirements were estimated based on the EAA profile of the whole body protein of prawn. As a result, the contents of EAA in dietary proteins (%) needed to meet the requirements of the prawn for EAA were assessed to be: threonine (2.3), methionine (1.3), valine (2.4), isoleucine (2.3), leucine (3.4), phenylalanine (2.6), lysine (3.2), histidine (1.1), arginine (2.9) and tryptophan (0.6), respectively, when the prawn are fed 50% protein diet with 90% protein digestibility at a ration size of 2% (% of body weight). [source] Evaluation of processed meat solubles as replacement for fish meal in diet for juvenile grouper Epinephelus coioides (Hamilton)AQUACULTURE RESEARCH, Issue 2001O M Millamena Abstract Feeding experiments were conducted to determine the efficacy of low fish-meal-based diets for juvenile grouper Epinephelus coioides (Hamilton). A diet containing 44% protein was formulated using fish meal as the major protein source. Processed meat solubles, a rendered by-product of slaughterhouses, was tested as a replacement for fish meal at increasing percentages from 0 to 100% in isonitrogenous diets. Eight dietary treatments representing fish-meal replacements were arranged in a completely randomized design with four replicates per treatment. Twenty-five fish were reared in circular fibreglass tanks of capacity 250 L, maintained in a flow-through seawater system and fed at 5,6% of total biomass, provided daily at 08:00 and 16:00 for 60 days. Results indicate that processed meat solubles can replace 40% of fish-meal protein with no adverse effects on weight gain, survival and or feed conversion ratio of E. coioides juveniles. Higher inclusion levels resulted in a significant decline in growth performance and inefficient feed conversion ratios, which may partly result from the lack of essential nutrients such as essential amino acids in meat solubles. This study has shown that the use of processed meat solubles substantially lowers the level of fish meal required in juvenile grouper diet and can be an efficient means of turning byproducts from slaughterhouses into a useful feed resource. [source] | |||||||||||||||||||