The process of protein digestion is a critical step for successful protein identification in the bottom-up proteomic analysis. To substitute the present practice of in-solution protein digestion, which is long, tedious, and difficult to automate, a lot of efforts have been dedicated for the development of a rapid, recyclable and automated digestion system. Recent advances of nanobiocatalytic approaches have improved the performance of protein digestion by using various nanomaterials such as nanoporous materials, magnetic nanoparticles, and polymer nanofibers. Especially, the unprecedented success of trypsin stabilization in the form of trypsin-coated nanofibers, showing no activity decrease under repeated uses for one year and retaining good resistance to proteolysis, has demonstrated its great potential to be employed in the development of automated, high-throughput, and on-line digestion systems. This review discusses recent developments of nanobiocatalytic approaches for the improved performance of protein digestion in speed, detection sensitivity, recyclability, and trypsin stability. In addition, we also introduce the protein digestions under unconventional energy inputs for protein denaturation and the development of microfluidic enzyme reactors that can benefit from recent successes of these nanobiocatalytic approaches.

For mass spectroscopy (MS)-based protein structural analyses, effective digestion by proteases is one of the key steps. In this study, we developed a protein digestion method using immobilized enzyme and a microscale vibration unit. Phospholipase A2 was applied as a model substrate to evaluate the new procedure due to its rigid structure and resistance to protease digestion. Digested substrates were analyzed by MS, and cleavage at all expected recognition sites was evaluated. In relation to conventional liquid-phase digestion, the number of matched peptides and sequence coverage improved significantly from 6 to 9, and 41% to 69%, respectively. These results support the efficacy of our novel method in proteomics applications, including protein structural and post-translational modification analyses.   

Crude glycerol derived from biodiesel production is characterized by its high concentration of organic carbon and its solubility in water; properties that make it a suitable co-substrate to improve the efficiency of a manure digester. An increase of about 400% in biogas production was obtained under mesophilic conditions when pig manure was co-digested with 4% of glycerol, on a wet-basis, compared to mono-digestion. The increase in biogas production was mainly a consequence of the increase in organic loading rate. However, the differences could also be related to the synergy between both substrates and the carbon-to-nitrogen ratio. Moreover, the analysis of the macro-compounds, protein, lipids, carbohydrates and fibers, showed lower removal efficiencies in the co-digester as the microorganisms obtained nutrients from the soluble carbohydrates provided by the glycerol. The digestate stability, evaluated through a respirometric assay, showed that co-substrate addition does not exert a negative impact on digestate quality. PMID:22341889

Phytic acid, polyphenols, protein and starch digestibility (in vitro) in two varieties, namely CS-46 and CS-88, of soaked, dehulled and germinated cowpeas were determined. Soaking for 12 hours, dehulling of soaked seeds and germination for different time periods (24, 36 and 48 h) contributed significantly in reducing the phytic acid and polyphenol content of cowpeas. Removal of seed coat (dehulling) of soaked cowpeas reduced the polyphenols by 70-71%. Soaking (12 h) brought about an improvement in protein and starch digestibility which further increased after dehulling. Progressive increase in digestibility (protein and starch) was noticed, with an increase in germination period. Dehulling of soaked seeds was most effective in reducing the polyphenolic content, and germination in enhancing protein and starch digestibility. PMID:10904935

Abstract The expression of peptides and proteins as fusions to the B1 domain of streptococcal protein G (GB1) is very popular since GB1 often improves the solubility of the target protein and because the first purification step using IgG affinity chromatography is simple and efficient. However, the following protease digest is not always complete or can result in a digest of the target protein. In addition, a further purification step such as RP-HPLC has to be used to get rid of the GB1 tag and undigested fusion protein. Because the protease digest and the following purification step are not only time-consuming but generally also expensive, we tested if GB1 fusion proteins can directly be used for NMR interaction studies using lipids or membrane-mimetics. Based on NMR binding studies using...

Plasma biomarkers studies are based on the differential expression of proteins between different treatment groups or between diseased and control populations. Most mass spectrometry-based methods of protein quantitation, however, are based on the detection and quantitation of peptides, not intact proteins. For peptide-based protein quantitation to be accurate, the digestion protocols used in proteomic analyses must be both efficient and reproducible. There have been very few studies, however, where plasma denaturation/digestion protocols have been compared using absolute quantitation methods. In this paper, 14 combinations of heat, solvent [acetonitrile, methanol, trifluoroethanol], chaotropic agents [guanidine hydrochloride, urea], and surfactants [sodium dodecyl sulfate (SDS) and sodium deoxycholate (DOC)] were compared with respect to their effectiveness in improving subsequent tryptic digestion. These digestion protocols were evaluated by quantitating the production of proteotypic tryptic peptides from 45 moderate- to high-abundance plasma proteins, using tandem mass spectrometry in multiple reaction monitoring mode, with a mixture of stable-isotope labeled analogues of these proteotypic peptides as internal standards. When the digestion efficiencies of these 14 methods were compared, we found that both of the surfactants (SDS and DOC) produced an increase in the overall yield of tryptic peptides from these 45 proteins, when compared to the more commonly used urea protocol. SDS, however, can be a serious interference for subsequent mass spectrometry. DOC, on the other hand, can be easily removed from the samples by acid precipitation. Examining the results of a reproducibility study, done with 5 replicate digestions, DOC and SDS with a 9 h digestion time produced the highest average digestion efficiencies (~80%), with the highest average reproducibility (<5% error, defined as the relative deviation from the mean value). However, because of potential interferences resulting from the use of SDS, we recommend DOC with a 9 h digestion procedure as the optimum protocol. PMID:15898154

Rice prolamin, constituting type-I protein body (PB-I), is indigestible and causes deterioration of rice protein nutritional quality. In this study, the in vivo digestibility of rice protein isolates was investigated by tracing their intraluminal transit in the gastrointestinal (GI) tract of rats by western blotting and by observing the structures excreted in the feces by electron microscopy. Two types of rice protein isolates, produced by alkali extraction (AE-RP) and by starch degradation (SD-RP), were compared. The protein patterns in the isolates were similar, but their digestion in the GI-tract showed striking differences. In the AE-RP group, 13-kDa prolamin (13P) quickly disappeared in the lower GI tract and was not excreted in the feces. By contrast, in the SD-RP group, 13P accumulated massively and nearly intact PB-Is were excreted. These results indicate that the in vivo digestibility of prolamin can be improved by alkali extraction through structural changes to it.   

An indigenously developed food mixture which contained huskless barley flour, green gram dhal flour, skimmed milk powder and tomato pulp ("BGMT" mixture) was autoclaved, cooled and fermented with L. acidophilus at 37 degrees C for 24 h at a dosage of 100,000 cells/ml. This process markedly reduced the phytic acid and polyphenol content and significantly improved the in vitro digestibility of starch and protein. Starch digestibility almost doubled in the fermented mixture. A significant negative relationship was obtained between the contents of antinutrients and digestibility. PMID:9131698

In this work, a novel kind of N-vinyl-2-pyrrolidinone (NVP) modified poly acrylic ester microspheres was prepared, followed by trypsin immobilization to prepare a hydrophilic immobilized enzyme reactor (IMER), to achieve highly efficient protein digestion with low peptide residue. The nonspecific adsorption of peptides on such an IMER was evaluated by the in sequence digestion of bovine serum albumin (BSA) and myoglobin. Without NVP modification, both proteins could be identified after digestion by a 5cm-length IMER, but 18 peptides of BSA were found in the digests of myoglobin caused by the nonspecific adsorption of the matrix. With NVP modification, the hydrophilicity of IMER was greatly improved, resulting in not only the sequence coverage of myoglobin increased from 63% to 73%, but als...

Gross energy, digestible energy, crude protein, and digestible crude protein were estimated for two leporids and five rodents that were the primary prey of coyotes (Canis latrans) in southeastern Idaho. Digestible protein estimates differed (38%-54%) more than digestible energy (3.5-4.4 kcal), in the prey examined. 15 references, 1 table.

Enzyme additives are believed to improve septic tank performance by increasing the hydrolysis and digestion rates and maintaining a healthy microbial population. Previous studies reported mixed results on the effectiveness of enzymes on mesophilic and thermophilic digestion, and it is not clear whether enzymes would be effective under septic tank conditions where there is no heating or mixing, quantities of enzymes added are small, and they can be washed out quickly. In this study, batch reactors and continuous-flow reactors designed and operated as septic tanks were used to evaluate whether enzymatic treatment would increase the hydrolysis and digestion rates in primary sludge. Total solids, volatile solids, total suspended solids, total and soluble chemical oxygen demand, concentrations of protein, carbohydrate, ammonia and volatile acids in sludge and effluent samples were measured to determine the differences in digestion rates in the presence and absence of enzymes. Overall, no significant improvement was observed in enzyme-treated reactors compared with the control reactors. PMID:22618603

The aspartic protease pepsin is less specific than other endoproteinases. Because aspartic proteases like pepsin are active at low pH, they are utilized in hydrogen deuterium exchange mass spectrometry (HDX MS) experiments for digestion under hydrogen exchange quench conditions. We investigated the reproducibility, both qualitatively and quantitatively, of online and offline pepsin digestion to understand the compliment of reproducible pepsin fragments that can be expected during a typical pepsin digestion. The collection of reproducible peptides was identified from >30 replicate digestions of the same protein and it was found that the number of reproducible peptides produced during pepsin digestion becomes constant above 5-6 replicate digestions. We also investigated a new aspartic protease from the stomach of the rice field eel (Monopterus albus Zuiew) and compared digestion efficiency and specificity to porcine pepsin and aspergillopepsin. Unique cleavage specificity was found for rice field eel pepsin at arginine, asparagine, and glycine. Different peptides produced by the various proteases can enhance protein sequence coverage and improve the spatial resolution of HDX MS data. This article is part of a Special Issue entitled: Mass spectrometry in structural biology. PMID:23063535

Protein malnutrition is a problem in Africa where sorghum is a staple foodstuff. Improvement in the protein quality of traditional African sorghum (Sorghum bicolor L. Moench) foods through the addition of cowpea (Vigna unguiculata L. Walp), an indigenous African legume, was investigated. Two sorghum cultivars, a red, tannin-type (NS 5511) and a white tan-plant, non-tannin type (Orbit) were complemented with cowpea (70:30 ratio). Ugali (thick porridge), uji (fermented thin porridge) and injera (fermented flatbread) were prepared. The protein lysine scores of cowpea-complemented foods were about double the levels of sorghum-only foods. The in vitro protein digestibility of the foods increased by 13-62%. The increase in lysine and protein digestibility improvement resulted in three- and two-f...

The effects of dry heat (roasting) and moist heat (boiling) on in vitro protein digestibility, protein fractions and other chemical properties of African breadfruit (Treculia africana Decne) seed that affect their utilization as a source of human food were investigated. Chemical analyses showed that the crude protein and fat contents of the unprocessed (raw) seeds were 20. 1% and 13.7%, respectively. The level of phytic acid in the raw seed (1.19 mg/g) was lower than the levels found in some commonly consumed pulses in Nigeria. Albumin and globulin protein fractions were found to be the major seed proteins of African breadfruit seed, constituting 67.8% of the total protein of the raw seed. There were no significant (p > 0.05) differences between crude protein, ash and fat contents of the raw and heat processed samples. Boiling proved more effective than roasting for improving protein digestibility and for reducing the levels of trypsin inhibitor, phytic acid and polyphenols of the samples. The complete removal of these antinutrients, however, would require a more severe heat treatment of the seed, which in turn would profoundly reduce the nutritional value and availability of proteins, as demonstrated by the low values obtained for in vitro protein digestibility, protein fractions and protein extractability. PMID:11318500

The digestion efficiency of the conventional anaerobic digestion treatment of sewage sludges is as low as 30% in organic substance decomposition rate. In order to improve the digestion efficiency, the effect of the digestion temperature, digestion period and stirring on the digestion efficiency has been examined. The digestion tests have been performed under various digestion conditions by varying the digestion period (5, 10, 20, 30 days), stirring cycle (2, 6, 12, 24 hr/day) and digestion temperature (35, 40 degrees C). The results of the experiments are provided.

Hyriopsis (Hyriopsis) bialatus has been cultured during the mussel life cycle from glochidia to the adult stage with a low total survival of 6% up to 130-day-old juveniles. The main digestive enzymes (amylase and proteinases) were not detectable in one-day-old juveniles, and increased during development. The stomach, including digestive glands, was the major digestive organ for both carbohydrate and protein. The optimum conditions for amylase activity were 40?C and pH 7; for acidic proteinases they were 60?C and pH 5. Two main alkaline proteinases were found in the intestine, with optimum conditions of 30?C and pH 8 and 60?C and pH 8. To improve mussel survival by finding suitable phytoplankton species and age as food for juveniles and adults, an in-vitro digestibility test was performed o...

Large differences exist in the degree to which different starch containing foods affect the blood glucose levels of both normal volunteers and diabetics. These differences appear to relate to the digestibility of the starch and the factors determining this, including: the interaction of starch with fiber, antinutrients (eg, phytate) and protein in the food, together with the nature of the starch itself and its physical form (eg, raw or cooked, ground or whole). In this respect legumes exemplify a class of foods, high in fiber, protein and antinutrients, with a starch which is digested slowly in vitro. They also produce relatively small blood glucose rises after consumption by both normals and diabetics and in the longterm result in improved diabetic control. Identification of more such foods and further understanding of factors determining starch digestibility will allow greater therapeutic use of diet in the management of diabetics and disorders of carbohydrate metabolism. PMID:6310984

The expression of peptides and proteins as fusions to the B1 domain of streptococcal protein G (GB1) is very popular since GB1 often improves the solubility of the target protein and because the first purification step using IgG affinity chromatography is simple and efficient. However, the following protease digest is not always complete or can result in a digest of the target protein. In addition, a further purification step such as RP-HPLC has to be used to get rid of the GB1 tag and undigested fusion protein. Because the protease digest and the following purification step are not only time-consuming but generally also expensive, we tested if GB1 fusion proteins can directly be used for NMR interaction studies using lipids or membrane-mimetics. Based on NMR binding studies using only the GB1 part, this fusion tag does not significantly interact with different membrane-mimetics such as micelles, bicelles, or liposomes. Thus spectral changes observed using GB1-fusion proteins indicate lipid- and membrane interactions of the target protein. The method was initially established to probe membrane interactions of a large number of mutants of the FATC domain of the ser/thr kinase TOR. To demonstrate the usefulness of the approach, we show NMR binding data for the wild type protein and a leucine to alanine mutant. PMID:22825779

Context: Coated whey protein micro-beads may improve probiotic protection and provide delayed cell-release mechanisms. Objective: Lactobacillus rhamnosus GG was encapsulated in whey protein micro-beads by droplet extrusion with coating via electrostatic deposition: primary-polysaccharide and secondary-whey protein. Materials and methods: Storage studies were performed in cranberry and pomegranate juice (pH 2.4; 28 days; 4 and 25degreeC) followed by simulated ex vivo porcine gastric (pH 1.6) and intestinal (pH 6.6) digestion. Results and discussion: After storage and simulated gastro-intestinal digestion, free cells, cells suspended in protein and cells encapsulated in alginate micro-beads, illustrated complete probiotic mortality, while coated micro-beads enhanced probiotic viability after...

The experiment was conducted to study the effects of fermentation of barley, using two different strains of lactic acid bacteria, a Lactobacillus plantarum/pentosus strain isolated from spontaneously fermented rye sourdough (AD2) and a starch-degrading Lactobacillus plantarum (AM4), on contents of mixed-linked (1 --> 3) (1 --> 4)-beta-glucans, alpha-amylase inhibitor activity, inositol phosphates, and apparent digestibility of macronutrients in mink. Effects of fermentation were compared with effects of gamma irradiation (gamma-irradiation: 60Co gamma-rays at 25 kGy). The diets were fed to mink with and without a supplementary enzyme preparation. Both lactic acid fermentation and gamma-irradiation followed by soaking and incubation, reduced concentrations of soluble beta-glucans, phytate and alpha-amylase inhibitor activity. Dietary enzyme supplementation increased significantly digestibility of crude protein, fat, starch and crude carbohydrate (CHO). Fermentation of the barley increased digestibility of starch and CHO. Fermentation with lactic acid bacteria AD2 resulted in higher starch and CHO digestibility than strain AM4, and had greater effect than gamma-irradiation, soaking and incubation. The highest digestibility of starch and CHO was obtained after AD2 fermentation followed by enzyme supplementation. It is concluded that both lactic acid fermentation of barley and enzyme supplementation have positive nutritional implications in the mink by limiting the effects of antinutrients and improving digestibility and energy utilization. PMID:17578263

Metabolic mechanisms underlying the divergent response of rainbow trout (Oncorhynchus mykiss) and Nile tilapia (Oreochromis niloticus) to changes in dietary macronutrient composition were assessed. Fish were fed one of four isoenergetic diets having a digestible protein-to-digestible energy (DP:DE) ratio above or below the optimal DP:DE ratio for both species. At each DP:DE ratio, fat was substituted by an isoenergetic amount of digestible starch as the non-protein energy source (NPE). Dietary DP:DE ratio did not affect growth and only slightly lowered protein gains in tilapia. In rainbow trout fed diets with low DP:DE ratios, particularly with starch as the major NPE source, growth and protein utilisation were highly reduced, underlining the importance of NPE source in this species. We also observed species-specific responses of enzymes involved in amino acid catabolism, lipogenesis and gluconeogenesis to dietary factors. Amino acid transdeamination enzyme activities were reduced by a low dietary DP:DE ratio in both species and in tilapia also by the substitution of fat by starch as the NPE source. Such decreased amino acid catabolism at high starch intakes, however, did not lead to improved protein retention. Our data further suggest that a combination of increased lipogenic and decreased gluconeogenic enzyme activities accounts for the better use of carbohydrates and to the improved glycaemia control in tilapia compared with rainbow tront fed starch-enriched diets with low DP:DE ratio. PMID:23168215

A biomass energy utilization project (Corn stalk->Cattle->Cattle dung->Biogas digester->Biogas/Digester residues->Soil) was conducted in a typical temperate agro-village of China from 2005 to 2010. The present study focused on two key approaches of the ecological loop: (1) increasing corn stalk use efficiency by improving anaerobic fermentation technology; and (2) enhancing biogas productivity by optimizing fermentation conditions. Our results showed that crude protein and fat of corn stalks significantly increased, while crude fiber content and pH decreased considerably during anaerobic fermentation. The cattle digestion rate, forage consumption and increases in cattle weight were higher in cattle fed fermented corn stalks than in those fed non-fermented corn stalks. The rate of biogas pr...

To more fully utilize defatted soybeans (DSB) as a food, various defatted soybean ontjoms (DSB ontjoms, fermented DSB with Neurospora intermedia) were prepared. The taste of DSB ontjoms was remarkably improved by adding 10% peanuts or 20% glandless cottonseeds (GLCS) to DSB. In the 20% GLCS-DSB ontjom, gossypol, the toxin of cotton seed, was not detected. The 10% peanut-DSB ontjom and the 20% GLCS-DSB ontjom contained about 50% crude proteins, about 25% soluble proteins, and a limited amount of undigesitible oligosaccharides related to flatulence. These DSB ontjoms to which oilseeds are added are expected to become popular as a digestible protein-rich wholesome and healty food.   

The use of soya and flaxseed flours fermented with Pediococcus acidilactici for wheat sourdough bread production was investigated. The protein digestibility, biogenic amine contents of soya and flaxseed sourdoughs, texture and sensory features of bread were studied. The fermentation with P. acidilactici significantly improved soya and flaxseed protein extraction and increased protein digestibility on an average by 13.5%. The concentrations of histamine (3.8 +- 2.3 and 4.0 +- 0.2 mg/kg), tyramine (4.6 +- 0.7 and 19.3 +- 1.8 mg/kg) and putrescine (66.4 +- 1.3 and 11.3 +- 3.0 mg/kg) do not present a health risk for consumers due to their relatively low levels in fermented plant products. The flaxseed sourdoughs influenced a 17.5% higher specific volume and a 4.6% lower crumb hardness of bread...

The carnivorous plant Dionaea muscipula (Venus’s flytrap) secretes proteinases into the digestive fluid to digest prey proteins. In this study, we obtained evidence that the digestive fluid contains a cysteine endopeptidase, presumably belonging to the papain family, through inhibitor studies and partial amino acid sequencing of the major SDS–PAGE band protein. The name “dionain” is proposed for the enzyme.   

The usefulness of carbohydrases in corn/soy-based diets for poultry is still unclear and all the more so when phytase is present in the feed. Though there are many interacting factors involved in dictating the measured response to an exogenous enzyme the most influential is the nutritional value of the diet to which it is added. The inherent ileal digestibility of starch, protein and lipid in a corn/soy-based diet varies from around 70% to over 95% and this variance explains up to 90% of the variance in enzyme response. An appreciation for the concentration of undigested starch, protein and lipid in any given diet is an important starting point for the prediction of the effect of the enzyme on digestible energy and amino acids. Instructively, around 15-25% of this undigested fraction can be rendered digestible with the addition of xylanase and so the magnitude of the response is largely explained by the quantity of this undigested portion. As phytase improves the digestibility of the diet, effectively reducing the concentration of undigested amino acids and energy it can be predicted that xylanase will deliver less value in a diet which has already been improved with phytase. It is the purpose of the current paper to describe these effects and the implications for the strategic selection of enzymes for corn/soy-based poultry diets.   

Abstract in portuguese Este estudo foi realizado para determinar a melhor relação lisina digestível:proteína digestível em rações para juvenis de tilápia-do-nilo. As tilápias (11,0 ± 0,43 g) foram distribuídas em 36 aquários (250 litros) numa densidade de seis peixes/aquário. Foram formuladas 12 rações com 22,0; 26,0 ou 30,0% de proteína digestível, com base na composição em aminoácidos digestíveis, e 4,5; 6,0; 7,5 ou 9,0% de lisina, em relação à proteína digestí (more) vel, fornecidas à vontade durante 60 dias. Houve interação significativa dos fatores lisina digestível/proteína digestível para o ganho de peso, uma vez que o aumento dos níveis de lisina em rações com 26,0 e 30,0% de proteína digestível promoveu aumento linear desse parâmetro. Os melhores valores de conversão alimentar foram obtidos com os níveis de 26,0 e 30,0% proteína digestível, que determinaram aumento do consumo diário de proteína digestível. O nível de lisina promoveu redução linear da conversão alimentar e aumento linear da taxa de eficiência proteica. O nível de 26,0% de proteína digestível pode ser utilizado em rações para juvenis de tilápiado-nilo, entretanto essas rações devem ser formuladas com aminoácidos digestíveis e relação lisina digestível/proteína digestível de 6,0%. Quando utilizados níveis superiores a 26,0% de proteína digestível, o nível máximo de 7,5% de lisina digestível em relação à proteína digestível melhora o ganho de peso na espécie. Abstract in english This study was carried out to determine the best digestible protein/digestible lysine ratio that should be present in feed fed to Nile tilapias. Two hundred and sixteen tilapias (11.0 ± 0.43g) were distributed in 36 fish tanks (205 L) at a density of 6 fish/tank. Twelve feeds were formulated with three different digestible protein (DP) levels 22.0; 26.0 and 30.0% (based on digestible amino acids) and four different lysine percentages of 4.5; 6.0; 7.5 or 9.0% in rel (more) ation to digestible protein. The fish were fed ad libtum during a 60-day period. There was significant effect of the digestible protein and digestible lysine ratio on weight gain, because the increase in lysine levels in feeds with 26 and 30% DP promoted linear increase in this parameter. The best values for feed conversion were obtained at the levels 26 and 30% DP that increased the daily consumption of digestible protein. The lysine level caused a linear reduction in feed conversion and linear increase in the protein efficiency rate. The results suggested that the 26% DP level might be used in ration to feed Nile tilapia juveniles; however, these should contain digestible amino acids and the digestible lysine/digestible protein ratio should be 6.0%. However, for levels higher than 26% DP, a maximum digestible lysine level of 7.5% DP improved weight gain for the species.

IGT's new biomass gasification process provides improved anaerobic digestion, particularly for organics of low biodegradability such as the cellulosics. In this improved anaerobic digestion of organic biomass, cells of microorganisms present in a digested biomass or untreated biomass fraction undergoing digestion are ruptured to obtain a treated biomass fraction having liberated indigenous enzymes in place. This treated biomass fraction is contacted with an untreated biomass fraction so the combined fractions undergo improved anaerobic digestion. The cells in the untreated biomass portion are ruptured by conventional means, such as sonication. Approximately equal volumes of the fractions are preferably combined under conditions of conventional anaerobic digestion.

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 vitro method that mimics digestive processes in the gastrointestinal tract of broiler chickens. An experiment was designed to use this method for predicting site, rate and extent of starch digestion in broiler chickens. In vitro starch digestion was studied in 12 experimental diets differing in starch sources. These diets were also used in a digestibility trial with broiler chickens. Correlations between in vitro and in vivo starch digestion were calculated. Starch digestion after 2 h incubation correlated well with in vivo starch digestion in the first half of the small intestine (r = 0.94). A 4-h incubation period resulted in a good correlation between in vitro starch digestion and ileal starch digestion (r = 0.96). In vitro starch digestion rate (h(-1)) correlated well with in vivo starch digestion rate (r = 0.87). In vitro starch digestion of individual starch sources was additive. It appeared that legume seeds and waxy corn contained two starch fractions, which were digested at different rates. We conclude that starch digestion rate in broiler chickens is well predicted by the in vitro method. PMID:11533276

An experiment was conducted to evaluate the effects of cereal carbohydrate form (isolated v. cereal matrix) and level, especially mixed-linked ?-glucan (hereafter referred to as ?-glucan) and starch amylase/amylopectin ratio on nutrient digestibility and fermentation parameters in the intestines of weaned pigs. Four hulless barley cultivars containing varying ?-glucan levels (41 to 84 g/kg) were compared with hulled barley, supplemented or not with a ?-glucan concentrate (BBG; 270 g/kg ?-glucan) and two oat cultivars for digestibility and fermentation metabolites. Seventy-two weaned piglets (BW = 12.8 ± 1.9 kg) were assigned to one of nine diets composed of 815 g/kg cereal, 60 g/kg whey, 90 g/kg soy protein isolate and 35 g/kg minerals. After 15 days, the pigs were killed, and digesta collected from ileum and colon were analyzed for proximate nutrients, short-chain fatty acids (SCFAs), lactic acid (LA) and ammonia. Ileal and total tract digestibility of proximate nutrients and non-starch polysaccharides (NSPs) were determined using HCl-insoluble ash as a marker. Organic matter (OM) ileal digestibility was greater (P digestibility, varying from 90% ± 0.3% for hulless barley to 67% ± 0.4% for oat, on average. NSP digestibility differed (P 0.05) was found for SCFA concentration in ileal contents, whereas in colonic contents, SCFA was lower in pigs fed oat (P pigs fed hulless barley than in pigs fed hulled barley and oat. Expressed per kg carbohydrate (NSP + starch) fermented, the ammonia concentration at the colon was lowest for hulled barley diets (supplemented with ?-glucan) and the highest for oat diets. In conclusion, the interaction of both form and level of ?-glucan impacted nutrient digestibility and fermentation. Hulless barleys with high soluble NSP such as ?-glucan and resistant starch yielded, in general higher SCFA and LA and lower ammonia. Hulless barleys may, therefore, have potential for use in feeding strategies designed to improve gut health in pigs. PMID:22444125

Dairy cattle selected for negative residual feed intake (n-RFI; efficient) should maintain production while reducing dry matter intake over a lactation because of improvements in feed digestion and efficient use of nutrients. The objective of this study was to measure nitrogen (N) digestibility and rumen microbial community composition over a short period during early lactation in lactating Holstein-Friesian cows selected previously for divergent RFI. It was proposed that n-RFI cows would have greater apparent digestibility of N than the positive RFI (p-RFI; inefficient) animals, to compensate for the lower dry matter intake determined during selection for divergence. Sixteen 3-yr-old rumen-cannulated, lactating cows (56 ± 10d in milk) selected for n-RFI (n = 8) and p-RFI (n = 8) were housed in metabolism stalls and fed fresh vegetative ryegrass (Lolium perenne L.) pasture ad libitum as a sole diet during an 8-d digestibility study. Intake of nutrients and outputs of milk, feces, and urine were determined. Rumen parameters were determined by removing, weighing, and sampling digesta, and by cobalt-EDTA dilution. Intakes of N, dry matter, organic matter, or its components did not differ with RFI. Compared with p-RFI cows, n-RFI cows had a greater apparent N digestibility (77.2 vs. 75.5%), and a tendency toward greater dry matter and organic matter digestibilities. The n-RFI cows had a lower fecal N output (126 vs. 138 g/d) and a lower partition of feed N to fecal N (23.1 vs. 24.7%) compared with p-RFI animals. We found no differences between phenotypes in the partition of N to urinary N or milk crude protein but did observe a trend for n-RFI cows to partition less N to milk casein (16.8 vs. 17.9%). Rumen digesta mass was similar for both groups, despite differences in calculated fractional liquid outflow rates, and most bacterial, archaeal, protozoal, and fungal communities were similar for both phenotype groups. In conclusion, dry matter intake and rumen function were similar for both phenotypes when the animals were fed highly digestible fresh ryegrass, but apparent digestibility of dietary N was higher in the efficient (n-RFI) cows. Future research should measure digestion parameters in cows with divergent RFI when fed diets differing in chemical composition (e.g., divergent crude protein contents). PMID:22916906

Inadequate nutrition is the main cause of low productivity by ruminants in sub-Saharan Africa. The primary feed resources in the region include natural pasture and crop residues that have tough texture, poor digestibility and are deficient in nutrients. These deficiencies can be corrected by supplementation with high-density feeds such as oilseed cakes and proteins of animal origin. However, protein sources such as oilseed cakes are beyond the economic reach of most farmers, while the incidence of bovine spongiform encephalopathy in Western intensive animal production may be thought to argue against the use of animal proteins. Local tree legumes have been investigated as potential supplements for ruminants because of their beneficial effect of increasing metabolizable energy intake, N intake and feed efficiency, and improving animal performance. However, our work has suggested that some plant materials may have a nutritional value beyond simply their nutrient content, i.e. as rumen-manipulating agents. The foliage of some tree legumes has been shown to be selectively toxic to rumen protozoa. Rumen protozoa ingest and digest bacteria and fungi, degrading their cellular protein to NH3. Microbial protein turnover due to protozoal predation in the rumen may result in the net microbial protein outflow being less than half the total protein synthesized. Results from in vivo experiments have clearly shown that duodenal flow of both undegraded dietary and bacterial protein is generally increased by defaunation. However, no practical method has been developed to date to eliminate protozoa. Anti-protozoal plants may be promising, safe, natural defaunating agents. PMID:10946789

1. A 35 d feeding trial with 480 d-old male broiler chickens (Cobb) was conducted to evaluate the effects of graded levels of inulin (0, 5, 10, 15 and 20 g/kg diet) in a maize-soybean meal based diet on growth performance, AMEN and apparent ileal digestibility (AID) of crude protein, amino acids, starch, crude fat and fatty acids. A commercial product (Inulina 95®) containing 914?0 g/kg of inulin and a degree of polymerisation (DP) ranging from DP 1-10 to DP 51-60 was used. 2. The performance of birds (feed intake, BW gain and feed to gain ratio) was not affected by the different dietary inclusions of inulin. 3. Dietary inulin significantly improved the AID coefficient of crude protein and crude fat. Also, there was a significant effect of inulin on the digestibility of most am...

For the purpose of developing an infant food of improved dispersibility characteristics and high nutritive quality, different treatments and technologies were applied to chickpea (Cicer arietinum). Samples were germinated for two and four days at room temperature (25 - 27 degrees C). One portion of each germinated chickpea sample was boiled for 40 min and the other portion was autoclaved at 15 psi for 15 min. These processed samples were then compared with the corresponding value of raw germinated and ungerminated samples as well as with the ungerminated processed ones for the following characteristics: chemical composition, contents of antiphysiological factors, solubility of proteins, lysine availability, net protein ratio (NPR), and digestibility of proteins. Germination caused an increase in the protein content of the seeds. No appreciable changes were observed in the trypsin inhibitor and tannin contents during germination. Availability of lysine was found slightly lower in the germinated seeds. The solubility of the nitrogenous constituents was markedly increased during germination. Along with processing, germination had no beneficial effect in improving protein quality, although digestibility of the proteins was increased. Boiling was more advantageous in the case of germinated seeds than autoclaving, whereas the reverse was true in the case of ungerminated seeds. PMID:3836608

The effects of various processing techniques on nutrient composition and anti-nutritional factors in baobab seeds (Adansonia digitata L.) and locust beans (Parkia filicoidea L.) were investigated. The methods used for processing include boiling in water, acid or alkali and fermentation. Using the water treated samples as controls, there were slight decreases in protein and carbohydrate contents of the fermented and alkali-treated meals. However, an increase in extractable oil content was observed in acid, alkali and fermented samples. The alkali treatment appeared to be the most effective method for reducing trypsin inhibitor and tannin contents and has the additional advantage of improving the protein digestibility. PMID:8837869

Bovine serum albumin (BSA) was chemically treated in the presence or absence of L-cysteine (Cys) after the cleavage of hydrogen bonds by urea and reduction of disulfide linkages by sodium tetrahydroborate. The reduced BSA was re-oxidized with hydrogen peroxide and Cys treated- or non-Cys treated- BSA was obtained (C-BSA or NC-BSA). The percentage of thiol groups modified in C-BSA was 73.6%. The peptic digestibility of BSA was markedly improved by chemical treatment in the presence of Cys. The pancreatic and tryptic digestibility of BSA was higher in the order of C-BSA>NC-BSA>native BSA. SDS-PAGE confirmed that chemical treatment with Cys improved the digestibility of BSA and facilitated protein fragmentation into small molecular weight peptides by protease. Further, enzyme-linked immunosorbent assay showed that the antigenicity of the tryptic digests of BSA was reduced about one-tenth by the chemical treatment with Cys. This result indicated that the change in conformation of BSA decreased the antigenicity through enhancement of protease susceptibility.   

The chemical composition and the protein quality of three samples of Lupinus mutabilis (a raw, semi-sweet variety; cooked, water-extracted seeds; and alcohol-extracted oil cake) were studied. The protein content varied from 47.7% dry weight (raw seeds) to 65.3% (oil-cake). Compared to the FAO reference pattern sulfur- containing amino acids are first limiting. The water-extracted sample contained 26.9% oil and the polyunsaturated/saturated fatty acid ratio of 30 seed samples was 5.3. Alkaloid content of raw seed was high (3.3%), but could be reduced or nearly eliminated by water-and-alcohol extraction or plant breeding. Other anti-nutritive substances were present only in trace quantities. Protein quality measured as protein efficiency ratio (PER) gave low values for the non-supplemented lupin proteins (1.34 semi-sweet variety; 1.53 water-extracted seeds; 1.19 oil-cake; 3.09 casein), but the PER's were improved by the addition of 0.2% DL-methionine to the diets (3.05, 2.69, 2,81, respectively). Raw as well as processed lupin protein showed an excellent apparent digestibility (80.0-85.8%, casein 87.1%). Studies of net protein utilization (NPU) and biological value (BV) confirmed the importance of methionine supplementation, The true digestibility of 92% was equivalent to that of casein. PMID:6275056

A review of past literature revealed inconsistencies in recommended feed particle size for optimal growth and productive performance of rabbits. Changing diet formulation and subsequent processing conditions may improve pellet texture and potentially affect rabbit performance. In the current study, two isoenergetic and isonitrogenous pelleted diets were formulated, which varied in the particle size of the concentrates (2 and 8 mm, respectively). The objective was to evaluate the effect of different particle sizes of compound diets on performance, nutrient utilisation, gut morphology, and carcass characteristics of fattening Italian White breed rabbits. The finely ground diet led to a significant improvement in feed efficiency and apparent digestibility of crude protein, ether extract,...

Abstract in portuguese Um experimento foi realizado para avaliar a soja integral (SI) processada a vácuo (SIvac) ou a vapor (SIvap) por meio da digestibilidade e do metabolismo em suínos. O delineamento experimental utilizado foi o inteiramente casualizado, com cinco tratamentos (dieta controle; dieta com SIvac; dieta com SIvap; 40% SIvac + 60% dieta controle; 40% SIvap + 60% dieta controle) e quatro repetições cada um, considerando o animal a unidade experimental. Os coeficientes de digest (more) ibilidade da energia bruta foram 4 e 3% inferiores para as dietas com substituição do farelo de soja por SIvac ou SIvap, respectivamente. A substituição do farelo de soja por SIvac ou SIvap não alterou a digestão e o metabolismo do nitrogênio em suínos. Para a SI, os teores digestíveis de proteína e energia foram 10,4 e 4,0% superiores com o processamento a vácuo. A digestibilidade das dietas e o metabolismo da energia são similares em suínos alimentados com dietas contendo SIvac ou SIvap. Em suínos alimentados com dietas com SIvac ou SIvap, a digestibilidade das dietas e o metabolismo do nitrogênio não são diferentes. O processamento a vácuo melhora os teores digestíveis de proteína e energia da soja integral. Abstract in english An experiment was carried out to evaluate the full-fat soybean (FFS) processed by vacuum (FFSvac) or by steam (FFSstm), by means of digestibility and metabolism of pigs. A completely randomized experimental design was used, with five treatments (control diet, diet with FFSvac, diet with FFSstm, 40% FFSvac + 60% control diet, 40% FFSstm + 60% control diet) and four replications each, being the animal the experimental unit. The digestibility coefficients of gross energy wer (more) e 4% and 3% lower for the diets with replacement of soybean meal by FFSvac or FFSstm, respectively. The replacement of soybean meal by FFSvac or FFSstm did not influence the digestion and the metabolism of nitrogen of the pigs. For FFS, the content of digestible protein and energy were 10.4 and 4.0% higher with vacuum processing. The diet digestibility and energy metabolism are similar in pigs fed with diets containing FFSvac or FFSstm. For pigs fed with diets containing FFSvac or FFSstm, the diet digestibility and nitrogen metabolism are not different. The vacuum processing improves the digestible contents of protein and energy of full-fat soybean.

Barley thioredoxin h isoforms HvTrxh1 and HvTrxh2 differ in temporal and spatial distribution and in kinetic properties. Target proteins of HvTrxh1 and HvTrxh2 were identified in mature seeds and in seeds after 72 h of germination. Improvement of the established method for identification of thioredoxin-targeted proteins based on two-dimensional electrophoresis and fluorescence labelling of thiol groups was achieved by application of a highly sensitive Cy5 maleimide dye and large-format two-dimensional gels, resulting in a 10-fold increase in the observed number of labelled protein spots. The technique also provided information about accessible thiol groups in the proteins identified in the barley seed proteome. In total, 16 different putative target proteins were identified from 26 spots using tryptic in-gel digestion, matrix-assisted laser-desorption ionization-time-of-flight MS and database search. HvTrxh1 and HvTrxh2 were shown to have similar target specificity. Barley alpha-amylase/subtilisin inhibitor, previously demonstrated to be reduced by both HvTrxh1 and HvTrxh2, was among the identified target proteins, confirming the suitability of the method. Several alpha-amylase/trypsin inhibitors, some of which are already known as target proteins of thioredoxin h, and cyclophilin known as a target protein of m-type thioredoxin were also identified. Lipid transfer protein, embryo-specific protein, three chitinase isoenzymes, a single-domain glyoxalase-like protein and superoxide dismutase were novel identifications of putative target proteins, suggesting new physiological roles of thioredoxin It in barley seeds

Three legumes [field peas (P), chickpeas (CP) and faba beans (B)] were evaluated at two inclusion levels; 170 (L) and 350?g kg?1 (H) in a 14-week experiment with triplicate groups of 97.9?6.1?g European seabass. A control diet included wheat meal, fish meal (FM) and a mixture of plant ingredients as protein sources. Diets, processed in a twin-screw extruder, were isonitrogenous and isoenergetic. All experimental diets improved growth compared to the control. Weight gain, feed intake, FCR and SGR were improved for fish fed diet CPL, while fish fed diet CPH gave higher FCR. Protein and starch digestibility were highest for the control diet, while fish fed diets CPL and PL showed significantly lower protein ADCs and lower starch ADC (P?0.05) for diet PH. Among H diets, significantly better fi...

Abstract in english This study was conducted with the objective of evaluating the effect of concentrate supplementation, formulated with different ingredients (Mesquite pod meal, sorghum meal or wheat meal and mineral supplementation) on performance, intake and digestibility of nutrients in Santa Inês lambs grazing on urochloa grass during the dry season. Twenty-four uncastrated weaned Santa Inês sheep, with average body weight (BW) 20±2 kg with an average of 120 days of age were used in (more) the assay. The experiment lasted 75 days. The animals grazing deferred Urochloa grass (Urochloa mosambicensis (Hack) Daudy) were distributed into four treatments consisting of mineral supplementation provided ad libitum and concentrated supplements containing mesquite pod meal, sorghum meal or wheat meal, supplied 10 g /kg BW on dry matter basis. The intakes of dry matter (DM) and crude protein (CP) were affected by the intake of concentrate supplement, regardless of the ingredients used in the supplements, compared with the mineral supplementation treatment, since the consumption of forage was reduced in 30% with mesquite pod meal supplement, and neutral detergent fiber (NDF) intake was not affected in relation to treatments. The digestibility of DM and CP were higher for treatments with supplements, and NDF digestibility did not differ between treatments. A significant difference was observed in the values of average daily gain for the treatments with concentrate supplementation compared with the one of mineral supplementation. The supplementation with concentrate in grazing enables improvement of performance, intake and digestibility of nutrients regardless of the ingredient used in the supplement.

Food allergy is a major health problem in the Western countries, affecting 3-8% of the population. What makes a dietary protein a food allergen has not yet been established, though several characteristics have been proposed to be shared by the food allergens. One of the features believed to be a general characteristic is resistance to digestion. This is based on studies showing that allergenic dietary proteins in general were more resistant to digestion than dietary proteins with no proven allergenicity, leading to the conclusion, that a correlation between stability to digestion and allergenic potential exist. Resistance to digestion is therefore a test parameter included in the safety assessment of the allergenic potential of novel proteins in genetically modified foods. In recent years, the association between resistance to digestion and allergenic potential has been challenged. When reviewing existing data from digestibility studies on known food allergens, it becomes evident that food allergens do not necessarily resist digestion. However, the choice of assay conditions, the method used for detection of residual intact protein as well as fragments hereof greatly influences the outcome. Studies assessing the allergenicity of digestion products, by either IgE-binding, elicitation or sensitising capacity, shows that digestion may abolish, decrease, have no effect, or even increase the allergenicity of food allergens. However, this dependents on the given allergen. In conclusion, reviewing existing digestibility data shows that no absolute correlation between resistance to digestion and allergenic potential exist. Therefore stability to digestion may not necessarily be a good parameter for assessing the allergenic potential of novel proteins. Even very small peptides from food allergens may retain both IgE-binding, eliciting and sensitising capacity. As a consequence immunological studies should be performed when evaluating the digestibility of protein allergens.

Effect of phytase produced by thermo-protective coating technology (coated phytase) on performance and nutrient utilization of broiler chicks fed a corn-soybean meal-based pelleted diet was investigated. A total of 144-one-day-old male broiler (Ross) chicks were divided in 24 groups and fed 4 diets (6 groups per diet) for 21 days. The diets included a mash or pelleted basal diet without or with the coated phytase at 500FTU/kg in a 2×2 factorial arrangement. Calcium and non-phytate P values in the basal diet were 22 and 51% lower compared with NRC (1994) recommended values, respectively. All the diets contained titanium oxide as an indigestible marker. There was no interaction (P>0.05) between diet form and phytase on any of response criteria measured in this study except body weight gain and feed intake such that phytase supplementation improved (P<0.05) these 2 response criteria, but improvements were greater for pelleted diet than mash diet. Phytase supplementation increased (P<0.05) tibia ash and ileal P digestibility, by 10.5 and 38.1%, respectively. Phytase supplementation did not, however, affect (P>0.05) the ileal digestibilities of Ca, crude protein and amino acids. In conclusion, coated phytase supplementation to corn-soybean meal-based diet for broilers resulted in improved growth performance, bone mineralization and P digestibility regardless of diet type (mash versus pellet). These findings suggest that the efficacy of the coated phytase used in the current study was not influenced by the pelleting process.   

We describe a solid phase microextraction (SPME), multistep elution, transient isotachophoresis (tITP) capillary electrophoresis-tandem mass spectrometry (CE-MS/MS) procedure which employs a high sensitivity porous electrospray ionization (ESI) sprayer for the proteomic analysis of a moderately complex protein mixture. In order to improve comprehensiveness and sensitivity over a previously reported proteomic application of the ESI sprayer, we evaluated preconcentration with SPME and multistep elution prior to tITP stacking and CE separation. To maximize separation efficiency, we primarily employed electrokinetic methods for elution and separation after loading the sample by application of pressure. Conditions were developed for optimum simultaneous electrokinetic elution and sample stacking using a tryptic digest of 16 proteins to maximize peptide identifications and minimize band broadening. We performed comparative proteomic analysis of a dilution series using CE and nanoflow liquid chromatography (nLC). We found complementary peptide and protein identifications with larger quantities (100 ng) of a Pyrococcus furiosus tryptic digest, but with mass-limited amounts (5 ng) CE was 3 times more effective at identifying proteins. We attribute these gains in sensitivity to lower noise levels with the porous CE sprayer, illustrated by better signal-to-noise ratios of peptide precursor ions and associated higher XCorr values of identified peptides when compared directly to nLC. From comparative analysis of SPME-tITP-CE with direct injection CE, the SPME-tITP process improved comprehensiveness and sensitivity. PMID:23004022

Antibody-binding fragments (Fab) are generated from whole antibodies by treatment with papain and can be separated from the Fc component using Protein-A affinity chromatography. Commercial kits are available, which facilitate the production and purification of Fab fragments; however, the manufacturer fails to report that this method is inefficient for antibodies with V(H)3 domains as a result of the intrinsic variable region affinity for Protein-A. A commercially available, modified Protein-A resin (MabSelect SuRe) has been engineered for greater stability. Here, we report that an additional consequence of the modified resin is the ability to purify V(H)3 family Fab fragments, which cannot be separated effectively from other components of the papain digest by traditional Protein-A resin. This improvement of a commonly used procedure is of significance, as increasingly, therapeutic antibodies are being derived from human origin, where V(H)3 is the most abundantly used variable region family. PMID:21738436

Abstract in portuguese Para melhorar a alimentação do pacu (Piaracatus mesopotamicus), é necessário conhecer o nível de aproveitamento dos ingredientes utilizados em suas dietas. Neste trabalho, inicialmente, foram analisados quatro métodos de coleta de fezes, em função da precisão e da versatilidade (dissecação, extrusão, Guelph e Guelph modificado), e o tempo entre as coletas de fezes nos sistemas de Guelph, por intermédio do coeficiente de digestibilidade da proteína bruta de u (more) ma dieta-referência para o pacu. Não houve diferença entre os métodos de coleta de fezes; já os intervalos de tempo das coletas apresentaram diferenças, podendo interferir nos resultados de digestibilidade da proteína. Em uma segunda etapa, para determinação dos coeficientes de digestibilidade da proteína e da energia de cinco concentrados protéicos de origem animal, cinco de origem vegetal e quatro energéticos, foram utilizadas rações elaboradas com 69,5% de uma dieta-referência, 30% do ingrediente teste e 0,5% de Cr2O3, utilizando o método de extrusão manual para a coleta de fezes. Os valores de digestibilidade da proteína da maioria dos alimentos apresentaram-se altos e não variaram estatisticamente, de 93,89 a 75,73% para o farelo de trigo e a farinha de penas, respectivamente. Entretanto, a farinha de sangue e a levedura apresentaram valores de digestibilidade da fração protéica significativamente inferiores (57,72 e 68,86%, respectivamente). Os coeficientes de digestibilidade da energia dos alimentos variaram consideravelmente, apresentando altos valores (acima de 90%) para o sorgo, o farelo de arroz e as sojas crua e tostada, e baixos valores (menores que 70%) para as farinhas de vísceras e de sangue, os farelos de soja e de algodão e a levedura. Quanto aos métodos de coleta de fezes, conclui-se que qualquer um pode ser adotado para a determinação de digestibilidade, desde que sejam rigorosamente aplicados. De maneira geral, a maioria dos concentrados protéicos pode ser utilizada como ótimas fontes de proteína, com exceção da farinha de sangue e a levedura, enquanto os alimentos energéticos confirmaram-se como excelentes fontes de energia em dietas para o pacu. Abstract in english To improve the pacu (Piaracatus mesopotamicus) feeding in the growth phase, it's necessary to know the digestibility of the ingredients used in his diets. Initially, four fecal collection methods were analyzed (dissection, stripping, Guelph and modified Guelph), based on precision and versatility and also the most efficient time among fecal collection of the Guelph sedimentation systems, through crude protein digestibility coefficient of pacu basic diet. There was no diff (more) erence among the fecal collection methods while the intervals of time among the collections were significantly different, which may interfere in the protein digestibility results. In a second stage, five proteins concentrated of animal origin, five of vegetable origin and four energetic were studied for estimating protein and energy digestibility coefficients using the stripping method. The rations contained 69.5% of a reference diet, 30.0% of the ingredient test and 0.5% of Cr2O3. In a general way, crude protein digestibility coefficients were high and did not differ from the wheat meal (93.89%) and feather flour (75.73%), respectively. However, blood and yeast showed lower crude protein digestibility (57.72% and 68.86%), respectively. Gross energy digestibility coefficients varied considerably among the feedstuffs, showing high values (above 90%) for the sorghum, rice meal and raw and toasted soy and lower values (smaller than 70%) for poultry by-product and blood meal, soybean meal, cotton and yeast. However, with regard to the fecal collection methods, the results showed that anyone can be adopted with safety for digestibility determination, if used accurately. In a general way, most of protein concentrate can be used as a very good protein source, except for blood meal and the yeast. The energy concentrate revealed to be a source of energy in pacu diets.

Data-dependent selective external ion ejection with improved resolution is demonstrated with a 3.5 tesla FTICR instrument employing DREAMS (Dynamic Range Enhancement Applied to Mass Spectrometry) technology. To correct for the fringing rf-field aberrations each rod of the selection quadrupole has been segmented into three sections, so that ion excitation and ejection was performed by applying auxiliary rf-only waveforms in the region of the middle segments. Two different modes of external ion trapping and ejection were studied with the mixtures of model peptides and a tryptic digest of bovine serum albumin. A mass resolution of about 100 had been attained for rf-only dipolar ejection in a quadrupole operating at a Mathieu parameter q of ~0.45. LC-ESI-DREAMS-FTICR analysis of a 0.1 mg/mL solution of bovine serum albumin digest resulted in detection of 82 unique tryptic peptides with mass measurement errors lower than 5 ppm, providing 100 % sequence coverage of the protein.

Summary 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 ni...

Abstract in portuguese Avaliou-se a qualidade da silagem de grãos úmidos de milho com adição de soja crua, por meio de medidas de digestibilidade parcial e total em bovinos. Foram utilizados três animais mestiços Nelore x Red Angus, implantados com cânulas ruminal e duodenal. O delineamento experimental foi o quadrado latino 3x3, com os seguintes tratamentos: SGM66= 60% de volumoso, 26,6% de silagem de grãos de milho e 13,4% de farelo de soja e milho moído; SGM33= 60% de volumoso, 13,4 (more) % de silagem de grãos de milho e 26,6% de farelo de soja e milho moído, e GMS= 60% de volumoso e 40% de farelo de soja e milho moído. A digestão e a digestibilidade da matéria seca não foram influenciadas pela inclusão de SGM na dieta. A dieta SGM66 aumentou a digestibilidade de matéria seca no intestino em relação à dieta GMS. Não houve efeito da inclusão da silagem de grãos na digestão e na digestibilidade das frações fibra em detergente ácido e fibra em detergente neutro da ração, bem como no fluxo ruminal e intestinal do amido. A SGM66 melhorou a digestibilidade total da proteína bruta, mas não mostrou efeito sobre a digestibilidade total da matéria seca, da fibra e do amido e sobre o ambiente ruminal no que se refere à acidez e à concentração de amônia. Abstract in english The quality of high moisture corn grain silage with addition of raw soybean grains was evaluated by measures of partial and total digestibilities in cattle. Three crossbred Nelore x Red Angus steers averaging 305kg of live weigth and fitted with ruminal and duodenal cannulas were used. The experimental design was a 3x3 Latin square, and the steers received the following treatments: HMGS66 = 60% roughage, 26.6% high moisture grain silage, and 13.4% soybean meal and ground (more) corn; HMGS33 = 60% roughage, 13.4% high moisture grain silage, and 26.6% soybean meal and ground corn; and GC = 60% roughage and 40% soybean meal and ground corn. The digestion and digestibility of dry matter was not influenced by the inclusion of HMGS in the diet. HMGS66 increased intestinal dry matter digestibility in relation to GC. The inclusion of high moisture corn grain silage did not affect acid detergent fiber and neutral detergent fiber digestions and digestibilities. The diet did not affect total intake of starch, as well ruminal and intestinal flow of starch. HMGS66 improved total digestibility of crude protein, but did not show effect on total digestibilities of dry matter, fiber, starch, and pH and ammonia concentration in the rumen.

Abstract in portuguese Avaliou-se a digestibilidade aparente de cinco rações isoproteicas e isoenergéticas contendo 0; 0,1; 0,2; 0,3 e 0,4g do complexo enzimático Bioenzimaplus (lipase, protease e carboidrase)/kg de ração na alimentação da tilápia-do-nilo. Foram utilizados 100 peixes distribuídos em cinco aquários de alimentação e cinco aquários de coleta de fezes. Os cinco tratamentos foram arranjados em delineamento inteiramente ao acaso com cinco repetições. Houve efeito line (more) ar de tratamento sobre a digestibilidade aparente (CDa) para proteína bruta e extrato etéreo. O CDa da proteína bruta e do extrato etéreo variaram de 81,60% a 84,93% e de 74,19% a 82,69%, respectivamente. Para carboidrato e energia bruta, o maior nível de suplementação resultou em maior CDa, 57,85% e 63,78%, respectivamente( P Abstract in english Apparent digestibility (ADC) of five isoproteic and isoenergetic diets containing 0, 0.1, 0.2, 0.3, and 0.4g/kg of enzymatic complex Bioenzimaplus (lipase, protease, and carbohydrase) for Nile tilapia was evaluated. A hundred fish were randomly assigned in five feeding aquaria, and five collecting feces ones. Treatments were composed by five enzymatic complex levels arranged in a completely randomized design in five repetitions. Significant differences (P(more) ved with the inclusion of enzymatic complex in the diets for ADC of crude protein and fat (linear effect). ADC of crude protein and fat varied from 81.60% to 84.94% and 74.19% to 85.69%, respectively. The highest enzyme supplementation level showed better digestibility values for carbohydrate and gross energy (57.85% and 63.78%, respectively). No difference was observed for ADC of dry matter showing values between 49.47% and 58.55%. The use of enzymes in Nile tilapia diets improved the digestibilities of protein, fat, carbohydrate, and gross energy digestibility.

The spotted rose snapper (Lutjanus guttatus) and bullseye puffer (Sphoeroides annulatus) are fish species from the tropical Eastern Pacific for which controlled production of larvae and juveniles has been accomplished in recent years. Diverse topics relating to their biology and aquaculture production are currently under study, in particular the nutrition and feeding aspects required to formulate practical feeds and rearing protocols. Improvements in larval growth and survival are possible by feeding live food organisms with natural or enhanced essential fatty acids content and highly digestible artificial microdiets. The ontogeny of the digestive tract and the expression and activity of digestive enzymes have been described for S. annulatus larvae. The effect of various protein and lipid levels on growth and feed utilization has been studied in juvenile and on-growing fish. Both species have carnivorous feeding habits and require high levels of protein in their diets, from 40% to 45% (dry weight) in spotted rose snapper and above 50% in bullseye puffer, with the younger stages requiring the highest protein levels. Encouraging results have been obtained in feeding experiments with different sources of dietary protein from animal and plant origin to evaluate their suitability as feed ingredients in practical diets. Optimization of fish culture practices through feeding management has also been investigated. Trials with various fish densities and feeding frequencies in intensive culture systems are providing information to improve feed utilization and growth in on-growing fish. Further research is underway to evaluate factors in broodstock nutrition which have an impact on egg and larval quality, and into the use of various commercially available oil sources in on-growing diets. In this paper, the results on nutrition and feeding research with both species are reviewed and research needs to support their commercial production in the region are discussed. PMID:19189236

The effects of palm kernel cake (PKC) as a protein source in a concentrate diet (comprising 35 % crushed maize, 30 % rice bran, 32 % PKC, 2 % vitamin mineral premix and 1 % salt) were examined on intake, live weight (LW) gain and digestibility in female goats (average LW of 12.4?±?2.6 kg). Four goats were randomly allocated to each of the four treatment diets: (a) Napier grass (Pennisetum purpureum) offered ad libitum (T1), (b) T1 + concentrate at 0.5 % of LW (T2), (c) T1 + concentrate at 1.0 % of LW (T3) and (d) T1 + concentrate at 2.0 % of LW (T4). A 7-day digestibility trial and an 82-day growth experiment were conducted. No differences were observed among diets for intakes of roughage dry matter (DM), total DM, organic matter (OM) and neutral detergent fibre (NDF). The crude protein (CP) intake increased (P??0.05) among treatments. The digestibility of dietary NDF decreased (P??0.05) difference between T2 and T3 diets. Supplementing a basal diet of Napier grass with PKC-based concentrate improved CP intake and LW gain. The PKC-based concentrate diet can therefore be exploited for the use of local feed resources for goat production; however, further research is required to achieve the best growth response. PMID:23096766

A rapid and reproducible system that couples capillary isoelectric focusing to a high-resolution mass spectrometer was developed for on-line analysis and identification of protein digests. Magnetic microsphere-based immobilized trypsin was used for protein digestion to reduce the digestion time to 10min, with a total analysis time of 4h. A three-protein-mixture (myoglobin, BSA, cytochrome c) with a molarity ratio of 1:10:50 was successfully digested and identified. This system was also used to analyze host cell protein impurities in a recombinant humanized monoclonal antibody product in which the sample was product-depleted using affinity capture on protein A/protein L columns prior to analysis. A database search identified 37 host cell proteins with peptide and protein identity probabilit...

protein tolerance of man, studies of carbohydrate requirements, and further work on ... in mice of digestibility and physiologically available energy. Quality of the protein of H. ...... namely, the pig-tailed monkey, Macaca nemestrina. of Southeast ...

Summary Response surface methodology was used to investigate the effects of extrusion conditions - namely moisture content (12.3-23.7-g 100-g-1) and temperature (150-178-C) - on physicochemical, antinutritional compounds, functional and pasting properties of extruded bean cotyledons. Results indicated that extrusion cooking did not change the chemical composition of bean flours, but completely eliminated the activity of the trypsin and -amylase inhibitors and haemagglutinins. The extrusion significantly improved starch and protein digestibility, water solubility and absorption of bean cotyledon. In addition, extrusion conditions significantly affected pasting properties, resulting in extrudate flours with different peaks and final viscosity values. From the results obtained in this work, i...

Mesophilic and thermophilic digestion of primary and activated sludge was investigated in lab scale reactors. Mixed primary and activated sludge was digested in one experiment and activated sludge was digested alone in another. The same gas yield, COD and dry solids reduction was obtained with both mesophilic and thermophilic digestion. However, more dissolved COD was found after thermophilic digestion. A gas yield of 370 and 225 l/kg dry solids was found for mixed sludge and activated sludge respectively. The filterability of the sludge decreased after thermophilic digestion, but a pre-treatment with addition of ferric chloride or elutriation with water prior to addition of polymer provided an acceptable filterability. Thermal hydrolysis at 180 deg C was tested as a pre-treatment prior to the digestion. This increased the gas yield by 22 % for mixed sludge and 24 % for activated sludge. Thermal hydrolysis further seemed to improve the dewaterability of the sludge after digestion 5 refs, 6 figs

Abstract in portuguese Avaliou-se o efeito do processamento do feno de alfafa (Medicago sativa L.) e da adição de óleo de soja em dietas sobre a digestibilidade total de matéria seca, matéria orgânica, proteína bruta, extrato etéreo, fibra em detergente neutro e fibra em detergente ácido em eqüinos. Utilizaram-se quatro potros machos, sem raça definida, com aproximadamente 14 meses de idade e 197,25 kg, em delineamento quadrado latino (4 × 4) e em arranjo fatorial (2 × 2), (more) composto de duas formas de fenação da alfafa (em cubos ou em ramas) e da adição ou não de óleo de soja em dietas contendo concentrado comercial na forma de péletes. A digestibilidade dos nutrientes foi determinada pelo método de coleta total de fezes durante três dias. A adição de óleo de soja refinado aumentou a digestibilidade total de matéria seca, matéria orgânica, extrato de etéreo e fibra em detergente neutro. A fenação da alfafa em cubos aumentou a digestibilidade total da proteína bruta, fibra em detergente neutro e da fibra em detergente ácido. A adição de óleo de soja nas dietas avaliadas foi um modo prático e seguro de aumentar a densidade calórica sem reduzir a digestibilidade dos macronutrientes orgânicos. O processamento da alfafa na forma de cubos melhorou a digestibilidade total da proteína bruta, fibra em detergente e fibra em detergente ácido da dieta em eqüinos. Abstract in english The effect of alfalfa hay processing (Medicago sativa L.) and the addition of soybean oil in diets on the total dry matter digestibility, organic matter, crude protein, ether extract, neutral detergent fiber and acid detergent in horses was evaluated. Four crossbred male foals with approximately 14 months of age and 197.25 kg were used and assigned in a (4 × 4) Latin square design with a factorial arrangement (2 × 2) composed of two alfalfa haying forms (cubes o (more) r branches) and the addition or absence of soybean oil in commercial diets containing concentrated in the form of pellets. The nutrients digestibility was determined by the total feces collection method for three days. The addition of refined soybean oil increased the total digestibility of dry matter, organic matter, ether extract and neutral detergent fiber. The alfalfa processing in the form of cubes increased the total digestibility of crude protein, neutral detergent fiber and acid detergent fiber. The addition of soybean oil in the assessed diets was a practical and safe way to increase the caloric density without reducing the digestibility of organic nutrients. The alfalfa processing in the form of cubes improved the total digestibility of crude protein, detergent fiber and acid detergent fiber in the diet of horses.

The hypothesis is that cereal proteases in liquid feed degrade and convert water insoluble storage protein into water soluble protein, which may improve the digestibility of protein in pigs compared with dry feeding. Protein utilization is increased by matching the amino acid (AAs) content of the diet as close as possible to the pigs’ requirement. By improving the availability of isoleucine, leucine, histidine and phenylalanine, which are limiting and commercial unavailable, the amount of crude protein in the pig feed can be reduced, resulting in a decreased excretion of nitrogen. The aim was to evaluate the effect of soaking on the amount of water soluble protein and AAs from different winter barley (Hordeum vulgare) cultivars. In this experiment, grains from 9 different barley cultivars were soaked and samples were collected at 15 minutes, 2, 4, 6, 8, 24, 48 and 72 hours. The protein concentration was analysed in the supernatant after centrifugation. After 15 min., app. 16% of the total protein was soluble and until 8 hours an increase of 5% units was observed. However, from 8 to 48 hours it increased with 10% units for some cultivars. Based on these analyses, cultivars were selected for amino acid analysis of water soluble protein at 4, 6 and 48 hours. The amount of glutamic acid after 48 hours indicated that the solubilised protein originated from the prolamin fraction in the grain. Comparison of the amount of isoleucine, leucine, phenylalanine and histidine in relation to the amount of glutamic acid revealed differences between the cultivars and the solubilised protein at all three times. These preliminary results may indicate that improvements of the nitrogen utilization in pigs fed soaked winter barley depends on the choice of cultivar and soaking time, and may serve as a new selection criterion for barley to be used in feeding.

Dehydration-responsive element-binding (DREB) proteins are important transcription factors in plant responses and signal transduction. The DREB proteins can improve the drought and salt tolerance of plants, which provides an excellent opportunity to develop stress-tolerant genetically modified crops in the future. In the present study, a novel TaDREB4 gene (GenBank Accession No: AY781355.1) from Triticum aestivum was amplified by PCR (polymerase chain reaction), and the recombinant plasmid pET 30a(+)/TaDREB4 was successfully constructed. The fusion protein was induced by IPTG (isopropyl ?-d-1-thiogalactopyranoside) and purified by the HisPrep™ FF 16/10 Column. The purity of the final purified TaDREB4 protein was 93.0%.Bioinformatic analysis and digestive stability tests were conducted to assess the allergenicity of the TaDREB4 protein, and acute toxicity tests were conducted in mice by oral administration of the TaDREB4 protein (5000mg/kg BW). The results indicated that there was almost no similarity between the TaDREB4 protein and known allergens, and the protein was immediately degraded in simulated gastric and intestinal fluid within 15 s. In addition, no observed adverse effects were found in mice after 14days. The results preliminary revealed that the protein is safe for human based on the current experiment. PMID:22735501

Switchgrass (Panicum virgatum L.) has been developed into a dedicated herbaceous bioenergy crop. Biomass yield is a major target trait for genetic improvement of switchgrass. microRNAs have emerged as a prominent class of gene regulatory factors that has the potential to improve complex traits such as biomass yield. A miR156b precursor was overexpressed in switchgrass. The effects of miR156 overexpression on SQUAMOSA PROMOTER BINDING PROTEIN LIKE (SPL) genes were revealed by microarray and quantitative RT-PCR analyses. Morphological alterations, biomass yield, saccharification efficiency and forage digestibility of the transgenic plants were characterized. miR156 controls apical dominance and floral transition in switchgrass by suppressing its target SPL genes. Relatively low levels of miR156 overexpression were sufficient to increase biomass yield while producing plants with normal flowering time. Moderate levels of miR156 led to improved biomass but the plants were non-flowering. These two groups of plants produced 58%–101% more biomass yield compared with the control. However, high miR156 levels resulted in severely stunted growth. The degree of morphological alterations of the transgenic switchgrass depends on miR156 level. Compared with floral transition, a lower miR156 level is required to disrupt apical dominance. The improvement in biomass yield was mainly because of the increase in tiller number. Targeted overexpression of miR156 also improved solubilized sugar yield and forage digestibility, and offered an effective approach for transgene containment.

Abstract in english Caseins are a family of milk proteins that exist in several molecular forms and are the main proteins present in the bovine milk. Genetic variants of these proteins have been associated with the quality and quantity of cheese derived from milk. Genotypes of 278 Frisón Negro Chileno cows were determined for k-casein by restriction fragment length polymorphism analysis of amplified DNA. A 350 bp fragment of the genomic bovine k(more) ONT>-casein gene was amplified by PCR. Two HINF I sites were found in the amplified fragment of allele A, one at position 134 and one at position 266; only the latter site is present in allele B. Thus, digests of alleles A yielded 84 bp and 132/134 bp bands and digests of alleles B resulted in 84 bp and 266 bp bands. These bands, and thus genotypes AA, AB and BB, were recognised by agarose gel electrophoresis and ethidium-bromide staining. This technique was used to determine the k-casein allelic frequency in a Frisón Negro dairy herd. The distribution of genotypes was slightly different, and the gene frequencies similar to those reported in the literature. This molecular genetic technique based on molecular markers allows direct genotyping for milk k-casein with certainty and accuracy in bulls and females to be used in programs of dairy cattle improvement. Therefore, an early and precise identification of milk protein genotypes should have a direct impact on dairy cattle breeding strategies

Lysine epsilon -amino group reacts with citraconic anhydride forming a derivative, which is stable on terms for trypsin cleavage. This modification changes the spectrum of peptides formed by the trypsin action; as the number of trypsin-sensitive sites is reduced, the peptides with higher molecular mass can survive in the digest. The various studies of proteins by MALDI-TOF mass spectrometry are often complicated by the low sequence coverage of the peptide chain. This paper demonstrates that the modification of proteins by citraconylation before trypsin cleavage represents a simple experimental technique, which allows a significant increase of sequence coverage in MALDI-TOF mass spectrometry. This improvement is caused both by change of trypsin fragmentation pattern and by disturbance of the protein's native tertiary structure. PMID:12767943

A novel experimental and computational technique based on multiple enzymatic digestion of a protein or protein mixture that reconstructs protein sequences from sequences of overlapping peptides is described in this SAND report. This approach, analogous to shotgun sequencing of DNA, is to be used to sequence alternative spliced proteins, to identify post-translational modifications, and to sequence genetically engineered proteins.

The effects of temperature during the ripening period on digestible protein contents of the rice grains of a seed-protein mutant rice cultivar LGCsoft were examined. The plants were grown under a natural condition until the booting stage, and then in temperature-controlled greenhouses set at 24.0ºC, 28.0ºC, and 30.6ºC (mean temperature). The protein compositions and the protein contents of the rice grains were analyzed quantitatively. The protein compositions in the LGCsoft grains varied with the temperature condition. The ratio of the digestible to total protein was higher in high-temperature conditions, and that of difficult-to-digest proteins, especially 13 kDa prolamin was lower in high-temperature conditions. The protein compositions in a normal-type cultivar Nihonmasari, which was the original cultivar of LGCsoft also varied with the temperature. However, the effect of temperature on the ratio of the digestible to total protein was larger in LGCsoft than in Nihonmasari. The ratios of the digestible protein in the grains under 24.0ºC and 30.6ºC conditions were 74.3% and 81.3%, respectively, in Nihonmasari. On the other hand, they were 52.0% and 63.1%, respectively, in LGCsoft. In LGCsoft, the total protein content of grains was 70.6-72.5 mg g-1, and it was affected only slightly by temperature during the ripening period. Therefore, the digestible protein content of grains under 24.0ºC and 30.6ºC conditions was 36.7 mg g-1 and 45.7 mg g-1, respectively, in LGC soft. It was clarified that the digestible protein content was higher at elevated temperatures because of the increased ratio of digestible to total protein.   

Mass spectrometry and peptide-centric approaches are powerful techniques for the identification of differentially expressed proteins. Despite enormous improvements in MS technologies, sample preparation and efficient fractionation of target analytes are still major bottlenecks in MS-based protein analysis. The complexity of tryptically digested whole proteomes needs to be considerably reduced before low abundance proteins can be effectively analyzed using MS/MS. Sample preparation strategies that use peptide-specific antibodies are able to reduce the complexity of tryptic digests and lead to a substantial increase in throughput and sensitivity; however, the number of peptide-specific capture reagents is low, and consequently immunoaffinity-based approaches are only capable of detecting small sets of protein-derived peptides. In this proof-of-principle study, special anti-peptide antibodies were used to enrich peptides from a complex mixture. These antibodies recognize short amino acid sequences that are found directly at the termini of the peptides. The recognized epitopes consist of three or four amino acids only and include the terminally charged group of the peptide. Because of its limited length, antibodies recognizing the epitope will enrich not only one peptide but a whole class of peptides that share this terminal epitope. In this study, ?-catenin-derived peptides were used to demonstrate that it is possible (i) to effectively generate antibodies that recognize short C-terminal peptide epitopes and (ii) to enrich and identify peptide classes from a complex mixture using these antibodies in an immunoaffinity MS approach. The expected ?-catenin peptides and a set of 38 epitope-containing peptides were identified from trypsin-digested cell lysates. This might be a first step in the development of proteomics applications that are based on the use of peptide class-specific antibodies. PMID:20962300

This research aimed at assessing the properties of guinea pig manure digestate from low-cost tubular digesters for crops fertilization in rural Andean communities. To this end, field trials were carried out to evaluate the effect of the digestate on two common Andean crops: potato (Solanum tuberosum) and forage (Lolium multiflorum and Trifolium pratense L.). The potato yield (20-25 tha(-1)) increased by 27.5% with digestate, by 15.1% with pre-compost and by 10.3% with the mixture, compared to the control. The forage yield (20-21 tha(-1)) increased by 1.4% with digestate - 50% dose, and by 8.8% with digestate - 100% dose and digestate - 150% dose, compared to the control. The results suggest that the digestate is an appropriate substitute of manure pre-compost for potato fertilization. The results with forage indicate that it can be applied in a range of doses, according to the amount produced by the digester. Currently, manure is either used for cooking or as fertilizer. With low-cost tubular digesters implementation, it could be used to feed the digester, using the digestate for crops fertilization and biogas for cooking; improving household living conditions and protecting the environment. Since soil properties in rural Andean communities differ from experimental layouts, the effect of fertilizers should be re-evaluated in-situ in future research studies. PMID:21903373

A series of exploratory anaerobic digestion experiments was performed with a mixed biomass-waste feed to search for digestion configurations that provide improved performance over that of conventional high-rate digestion. The techniques studied were pretreatment of the feed with caustic soda, product gas recycling to the digester, recycling of aerobically treated digester effluent to the digester, two-phase digestion with complete mix acid- and methane-phase reactors, and packed-bed, methane-phase digestion of the effluent from an acid-phase reactor. Ambient-temperature pretreatment of the feed blend with dilute caustic and recycling of the product gas each afforded higher methane yields and volatile solids reduction efficiencies than high-rate digestion alone. It was found that spent caustic could be recycled for fresh feed pretreatment and that neutralization was not necessary before feeding to the digester. Two-phase digestion in the complete-mix reactors gave methane yields and reduction efficiencies about the same as those of high-rate digestion but at much higher loadings and reduced detention times thereby offering significant reductions in equipment size for the same throughputs. The use of a packed-bed anaerobic filter as a methane-phase reactor also showed considerable promise for operation at reduction detection times when the filter effluent was recycled to the filter inlet. Analysis of the data from the experiments conducted to study each advanced digestion technique indicates that an integrated series of unit processes consisting of dilute caustic pretreatment, thermophilic acid-phase digestion, mesophilic complete-mix and packed-bed methane-phase digestion, and limited-aeration aerobic treatment of the methane-phase effluents coupled with recycling should exhibit digestion efficiencies and methane yields near the upper practical limits.

Urinary exosomes have received considerable attention as a potential biomarker source for the diagnosis of renal diseases. Notwithstanding, their use in protein biomarker research is hampered by the lack of efficient methods for vesicle isolation, lysis, and protein quantification. Here we report an improved ultracentrifugation-based method that facilitates the solubilization and removal of major impurities associated with urinary exosomes. A double-cushion sucrose/D(2)O centrifugation step was used after a two-step differential centrifugation to separate exosomes from the heavier vesicles. After the removal of uromodulin, 378 and 79 unique proteins were identified, respectively, in low- and high-density fractions. Comparison of our data with two previously published data sets helped to define proteins commonly found in urinary exosomes. Lysis, protein extraction, and in-solution digestion of exosomes were then optimized for MudPIT application. More than a hundred exosomal proteins were quantified by four-plex iTRAQ analysis of single and pooled samples from two different age groups. For healthy men, six proteins (TSN1, PODXL, IDHC, PPAP, ACBP, and ANXA5) showed significant expression differences between exosome pools of those aged 25-50 and 50-70 years old. Thus, exosomes isolated by our method provide the basis for the development of robust quantitative methods for protein biomarker research. PMID:22418980

When massively expressed in bacteria, recombinant proteins often tend to misfold and accumulate as soluble and insoluble nonfunctional aggregates. A general strategy to improve the native folding of recombinant proteins is to increase the cellular concentration of viscous organic compounds, termed osmolytes, or of molecular chaperones that can prevent aggregation and can actively scavenge and convert aggregates into natively refoldable species. In this study, metal affinity purification (immobilized metal ion affinity chromatography [IMAC]), confirmed by resistance to trypsin digestion, was used to distinguish soluble aggregates from soluble nativelike proteins. Salt-induced accumulation of osmolytes during induced protein synthesis significantly improved IMAC yields of folding-recalcitrant proteins. Yet, the highest yields were obtained with cells coexpressing plasmid-encoded molecular chaperones DnaK-DnaJ-GrpE, ClpB, GroEL-GroES, and IbpA/B. Addition of the membrane fluidizer heat shock-inducer benzyl alcohol (BA) to the bacterial medium resulted in similar high yields as with plasmid-mediated chaperone coexpression. Our results suggest that simple BA-mediated induction of endogenous chaperones can substitute for the more demanding approach of chaperone coexpression. Combined strategies of osmolyte-induced native folding with heat-, BA-, or plasmid-induced chaperone coexpression can be thought to optimize yields of natively folded recombinant proteins in bacteria, for research and biotechnological purposes. PMID:16333986

The present study was conducted to investigate the effects of varying dietary protein levels on amino acid digestibility at different sites of fistulized chicken intestines. Chickens were fistulized to either the middle part of the jejunum (MJ), the distal end of the jejunum, the middle part of the ileum, the distal end of the ileum or the distal end of the rectum (DR). Intestinal digesta were collected from each site of the intestine, and contents of amino acids were measured. The true digestibilities of all amino acids in intestinal digesta at MJ were significantly lower than those at DR in the 10% protein group. In the 15% protein group, the true digestibilities of Asp, Thr, Glu, Pro, Gly, Val, Met and Ile in intestinal digesta at MJ were significantly lower than those at DR. The true digestibility of Ser in intestinal digesta at MJ was significantly lower than that at DR in the 20% protein group. In the 30% protein group, there was no significant difference in the true digestibilities of amino acids in intestinal digesta between the sites of the intestine. The true digestibilities of all amino acids in intestinal digesta at MJ in the 10% protein group were significantly lower than those in other groups. These results clearly demonstrated that dietary protein levels influence amino acid digestibility at MJ in chickens.   

Digestion gas produced through the anaerobic digestion of sewage sludges contains 60 to 70% methane, 40 to 30% carbon dioxide and small quantities of nitrogen and hydrogen sulfide. This paper describes the quantity of digestion gas available at the present for power generation, the present state and the future subjects of digestion gas power generation and the background and the summary of the Methatopia Project, a project planned to investigate the possibility of digestion gas power generation, to develop systems and apparatus for digestion gas power generation and to test and improve the digestion gas power generating systems and apparatus through the operation of an actual-scale demonstration facility, in terms of the purpose, annual scenario, the site and management, the constitution of the system and the quantity of electric power generated by the system.

Bacterial proteins represent a potential future nutrient source for monogastric animal production because they can be grown rapidly on substrates with minimum dependence on soil, water, and climate conditions. This review summarises the current knowledge on methane-utilising bacteria as feed ingredients for animals. We present results from earlier work and recent findings concerning bacterial protein, including the production process, chemical composition, effects on nutrient digestibility, metabolism, and growth performance in several monogastric species, including pigs, broiler chickens, mink (Mustela vison), fox (Alopex lagopus), Atlantic salmon (Salmo salar), rainbow trout (Oncorhynchus mykiss), and Atlantic halibut (Hippoglossus hippoglossus). It is concluded that bacterial meal (BM) derived from natural gas fermentation, utilising a bacteria culture containing mainly the methanotroph Methylococcus capsulatus (Bath), is a promising source of protein based on criteria such as amino acid composition, digestibility, and animal performance and health. Future research challenges include modified downstream processing to produce value-added products, and improved understanding of factors contributing to nutrient availability and animal performance. PMID:20578647

Digesta viscosity, ileal transit time of digesta, apparent ileal protein digestibility and apparent metabolisable energy (AME(N)) of diets based on wheat and dehulled barley (WB), oats (O) or a mixture of these (WBO) fed as such or with enzyme supplementation in three- and six-week old turkeys and broilers were investigated. In addition, differences between ileal digestibility and AME(N) calculated by using titanium dioxide (TiO2), chromic oxide (Cr2O3) or acid insoluble ash (AIA) as indigestible markers were compared. Digesta viscosities were generally moderate reaching from 2.5 mPa x s to 7.3 mPa x s. The highest viscosities were observed in WBO diets. Viscosities were reduced with age in broilers, and were generally higher in turkeys than in broilers, especially at six weeks of age. Digesta retention time in ileum was elongated with age of the birds, pronouncedly in broilers. Oat inclusion to the diets decreased retention time especially in broilers at six weeks of age. Apparent ileal digestibility of protein ranged from 0.64-0.83, was lower at six weeks of age than at three weeks of age and generally lowest in O diets, especially in turkeys. AME(N) of the diets ranged from 11.2-13.4 MJ/kg being higher at six weeks of age than at three weeks of age. AME(N) of Diets O was the lowest but AME(N) of WBO diets was higher than that of WB diets indicating a synergistic interaction of cereals, this trend being more pronounced in broilers. Enzyme supplementation decreased viscosity and improved AME(N) in most diets, but did not affect ileal protein digestibility. Differences between ileal digestibility estimates obtained with TiO2 or Cr2O3 were small and mainly not significantly different from 0. AME(N) estimates were generally higher when calculated with Cr2O3 than with TiO2. AIA gave remarkably lower AME(N) values than TiO2 (the significant differences ranging from 0.24-0.94 MJ/kg). In addition, effects of markers on AME(N) estimates interacted with age of the birds and dietary treatments. PMID:20578651

A comprehensive approach to protein identification and determination of sites of posttranslational modifications (PTMs) in heavily modified proteins was tested. In this approach, termed "reconstructed molecular mass analysis" (REMMA), the molecular mass distribution of the intact protein is measured first, which reveals the extent and heterogeneity of modifications. Then the protein is digested with one or several enzymes, with peptides separated by reversed-phase HPLC, and analyzed by Fourier transform mass spectrometry (FTMS). Vibrational excitation (collisional or infrared) or electron capture dissociation (ECD) of peptide ions provides protein identification. When a measured peptide molecular mass indicates the possibility of a PTM, vibrational excitation is applied to determine via characteristic losses the type and eventually the structure of the modification, while ECD determines the PTM site. Chromatographic peak analysis continues until full sequence coverage is obtained, after which the molecular mass is reconstructed and compared with the measured value. An agreement indicates that the PTM characterization was complete. This procedure applied to the bovine milk PP3 protein containing 25% modifications by weight yielded all known modifications (five phosphorylations, two O- and one N-glycosylation) as well as the previously unreported NeuNAc-Hex-[NeuNAc]HexNAc group O-linked to Ser60. With the FTMS performance improved, REMMA can serve as the basis for high-throughput, high-sensitivity PTM characterization of biological important proteins, which should speed up the proteomics research.

Background Virus-binding activity is one of the important functions of fibronectin (FN). It has been reported that a high concentration of FN in blood improves the transmission frequency of hepatitis viruses. Therefore, to investigate a protease that hydrolyzes FN rapidly is useful to decrease the FN concentration in blood and HBV infection. So far, however, no specific protease digesting FN in serum has been reported. Methods We employed a purified earthworm protease to digest serum proteins. The rapidly cleaved protein (FN) was identified by MALDI-TOF MS and western blotting. The cleavage sites were determined by N-terminus amino acid residues sequencing. The protease was orally administrated to rats to investigate whether serum FN in vivo became decreased. The serum FN was determined by western blotting and ELISA. In cytological studies, the protease was added to the medium in the culture of HepG2.2.15 cells and then HBsAg and HBeAg were determined by ELISA. Results The protease purified from earthworm Eisenia fetida was found to function as a fibronectinase (FNase). The cleavage sites on FN by the FNase were at R and K, exhibiting a trypsin alkaline serine-like function. The earthworm fibronectinase (EFNase) cleaved FN at four sites, R259, R1005, K1557 and R2039, among which the digested fragments at R259, K1557 and R2039 were related to the virus-binding activity as reported. The serum FN was significantly decreased when the earthworm fibronectinase was orally administrated to rats. The ELISA results showed that the secretion of HBeAg from HepG2.2.15 cells was significantly inhibited in the presence of the FNase. Conclusion The earthworm fibronectinase (EFNase) cleaves FN much faster than the other proteins in serum, showing a potential to inhibit HBV infection through its suppressing the level of HBeAg. This suggests that EFNase is probably used as one of the candidates for the therapeutic agents to treat hepatitis virus infection. PMID:15627336

Administration of the multipotent hematopoietic progenitor cell (HPC) line DKmix improved cardiac function after myocardial infarction and accelerated dermal wound healing due to paracrine mechanisms. The aim of this study was to analyse the secreted proteins of DKmix cells in order to identify the responsible paracrine factors and assess their relevance to the wide spectrum of therapeutic effects. A mass spectrometry (MS)-based approach was used to identify secreted proteins of DKmix cells. Serum free culture supernatants of DKmix-conditioned medium were collected and the proteins present were separated, digested by trypsin and the resulting peptides were then analyzed by matrix-assisted laser desorption/ionization tandem time-of-flight (MALDI-TOF/TOF) MS. Overall 95 different proteins were identified. Among them, secretory proteins galectin-3 and gelsolin were identified. These proteins are known to stimulate cell migration and influence wound healing and cardiac remodelling. The remaining proteins originate from intracellular compartments like cytoplasm (69%), nucleus (12%), mitochondria (4%), and cytoplasmic membrane (3%) indicating permeable or leaky DKmix cells in the conditioned medium. Additionally, a sandwich immunoassay was used to detect and quantify cytokines and chemokines. Interleukin-6 (IL-6), interleukin-13 (IL-13), monocyte-chemoattractant protein-1 (MCP-1), monocyte-chemoattractant protein-3 (MCP-3), monocyte-chemoattractant protein-1alpha (MIP-1alpha) and monocyte-chemoattractant protein-1beta (MIP-1beta) were detected in low concentrations. This study identified a subset of proteins present in the DKmix-conditioned medium that act as paracrine modulators of tissue repair. Moreover, it suggests that DKmix-derived conditioned medium might have therapeutic potency by promoting tissue regeneration. PMID:20127908

The digestion of proteins in steamed rice grains by sake koji enzymes under simulated sake mash conditions was analyzed by comparing the hydrolysis of steamed rice grains and heat-treated protein bodies (PBs) isolated from seven rice samples including four endosperm-storage protein mutants. The disappearance of peptides in the digest of isolated PBs was faster than that of steamed rice grains; however, more insoluble proteins formed in the case of isolated PBs. Not all of the hydrolyzed PB proteins were immediately solubilized in the digestion tests. High-molecular-weight peptides were more abundant in the solubilized digest of steamed rice grains than in that of isolated PBs. Variance in Ile, Ser, Glu, and Gly levels in the digest of steamed rice grains was relatively high among the seven samples, but was not found to be high in digests of isolated PBs. These results indicate that factors that may be derived from the steamed rice grains profoundly affect the digestion of proteins in steamed rice grains by sake koji enzymes.   

The use of high resolution mass spectrometry to detect signature peptides within proteolytic digests of the isolated matrix M1 protein, and whole virus digests, for both human and animal strains of influenza is shown to be able to rapidly and reliably type the virus. Conserved sequences for predicted tryptic peptides were identified through alignments of matrix M1 protein sequences across all human, avian and swine strains of the influenza virus. Peptides with unique masses, when compared with those from the in silico digestion of all influenza antigens and those proteins known to contaminate egg grown strains, were identified using the purpose built FluGest algorithm. Their frequency of occurrence within the matrix M1 protein across all type A and type B strains was established with the FluAlign algorithm. The subsequent detection of the signature peptides of matrix M1 protein within proteolytic digests of type A and type B human and avian strains has been demonstrated. PMID:20117137

Restriction enzyme digestion patterns of the large virulence plasmids of 8 human and 37 foal isolates of virulence-associated protein (VapA)-positive Rhodococcus equi strains from different sources were compared. Foal isolates came from five continents. Digestion with EcoRI divided these plasmids in...

The spectrum of Tenebrio molitor larvae digestive proteinases was studied in the context of spatial organization of protein digestion in the midgut. The pH of midgut contents increased from 5.2–5.6 to 7.8–8.2 from the anterior to the posterior. This pH gradient was reflected in the pH optima of the ...

Studies were performed as part of an ongoing comprehensive research program to develop and optimize the anaerobic digestion process for producing methane from sea kelp (Macrocystis pyrifera). Laboratory-scale studies focused on digester design and operating techniques applicable toward the goal of increasing methane yields and production rates over those observed in previous studies using conventional stirred tank reactors (STR). Two unconventional anaerobic digesters, an upflow solids reactor and a baffle flow reactor, were used to study the anaerobic digestion performance of kelp; both digesters permit solids retention times that are longer than the hydraulic retention times. The performance of the unconventional digesters was compared with that of the STR on the basis of methane yield and process stability. These studies demonstrated that, although digester performance was markedly affected by kelp variability, the methane yield in both unconventional digesters exceeded 70% of the theoretical yield and was substantialy higher than that of the STR. Utilization of simple digester designs that promoted long solids retention times improved the anaerobic digester performance significantly over that observed in conventional anaerobic digestion processes.

The genus Nepenthes comprises carnivorous plants that digest insects in pitcher fluid to supplement their nitrogen uptake. In a recent study, two acid proteinases (nepenthesins I and II) were purified from the pitcher fluid. However, no other enzymes involved in prey digestion have been identified, although several enzyme activities have been reported. To identify all the proteins involved, we performed a proteomic analysis of Nepenthes pitcher fluid. The secreted proteins in pitcher fluid were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and several protein bands were detected by silver staining. The proteins were identified by in-gel tryptic digestion, de novo peptide sequencing, and homology searches against public databases. The proteins included homologues of beta-D-xylosidase, beta-1,3-glucanase, chitinase, and thaumatin-like protein, most of which are designated "pathogenesis-related proteins". These proteins presumably inhibit bacterial growth in the pitcher fluid to ensure sufficient nutrients for Nepenthes growth. PMID:18183948

Micro-aeration, which refers to the addition of very small amounts of air, is a simple technology that can potentially be incorporated in septic tanks to improve the digestion performance. The purpose of this study was to investigate and compare the effects of micro-aeration on anaerobic digestion of primary sludge under septic tank conditions. 1.6 L batch reactor experiments were carried out in duplicate using raw primary sludge, with 4.1 % total solids, and diluted primary sludge, with 2.1 % total solids. Reactors were operated for 5 weeks at room temperature to simulate septic tank conditions. Micro-aeration rate of 0.00156 vvm effectively solubilised chemical oxygen demand (COD) and improved the subsequent degradation of COD. Micro-aeration also increased the generation of ammonia and soluble proteins, but did not improve the reduction in total and volatile solids, or the reduction in carbohydrates. Experiments using diluted sludge samples showed similar trends as the experiments with raw sludge, which suggest that initial solids concentration did not have a significant effect on the degradation of primary sludge under septic tank conditions. PMID:22903593

Summary The influence of natural fermentation (NF) and controlled fermentation (CF) in diminishing the content of antinutrients, a-galactosides and increments in in vitro protein digestibility was investigated. The dry bean (Phaseolus vulgaris) flour was the substrate used in this research study. A decrease in raffinose oligosaccharide, antinutritional components and pH was observed in both types of fermentation. The natural lactic fermentation of ground beans produced significant increase (P a-galactosides content of the flours during fermentation. NF is an inexpensive method by which consumers can obtain good-quality protein. Both types of fermentation diminish antinutrients and improve the nutritional value of the bean flour, and indicate the potential to use bean flour as an ingredient...

Abstract Factors influencing apparent digestibility coefficient (ADC) of nutrients from a plant protein-based diet supplemented with microbial phytase were investigated in a series of experiments with rainbow trout (Oncorhynchus mykiss). The influence of phytase level, water temperature, feed particle size and addition of a protease/non-starch polysaccharidase (PNSP) enzyme cocktail were tested in a phytase-supplemented (2000-FTU-kg-1) diet. Finally, the influence of Ca/P ratio, addition of 1,25-hydroxycholeocalciferol, or inclusion of lactic acid (LA) in diets with and without phytase was evaluated. Addition of microbial phytase improved ADC of dry matter (DM), protein, ash and minerals (P, Ca, Mg, Fe and Zn) (P--0.05). Reducing feed particle size potentiated the effect of phytase on P an...

An algae culture grown on the water from the digested slurry of a biogasification plant serves as a means of removing CO/sub 2/ from the methane stream while purifying the wastewater and providing more biomass for the anaerobic digestion plant. Tested on a sewage-sludge digestion system, the proposed process improved the methane yield by 32% and methane concentration by 53-98 vol % while lowering the concentration of nitrogen and phosphorus in the final water.

The histopathological effects of Zygocotyle lunata, Echinostoma trivolvis, and Ribeiroia ondatrae in naturally infected Helisoma trivolvis were studied in hematoxylin and eosin sections of infected digestive glands fixed in 10% neutral buffered formalin. The larval stages of all three trematodes damaged the snail digestive gland. Most notable histopathology included disrupted digestive gland tubules, lysed cells, compressed tubules, and edematous spaces between tubules. Considerable damage was done by rediae ingesting digestive cells. There was a detectable hemocytic response by H. trivolvis in response to the rediae and cercariae of Z. lunata. Histochemical studies on sectioned material stained with the Ayoub-Shklar method for keratin detected the presence of this protein in the rediae an...

Abstract in portuguese Este trabalho foi conduzido com os objetivos de avaliar a ingestão e a digestibilidade da matéria seca e dos nutrientes e estimar o valor energético de rações com 0; 25; 50; 75 ou 100% de casca do grão de soja em substituição ao milho moído na dieta de cabritos. As rações foram compostas de feno de aveia, milho moído e/ou casca do grão de soja, farelo de soja e suplemento mineral. Foram utilizados cinco cabritos da raça Saanen (32,44 ± 4,00 kg) alojados em (more) gaiolas de digestibilidade em delineamento quadrado latino 5 × 5. Foram realizadas coletas totais de fezes utilizando-se sacolas de lona. Cada período foi composto de 12 dias (sete dias para adaptação à ração e cinco dias para coletas). As ingestões de matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), carboidratos totais (CT) e nutrientes digestíveis totais (NDT) não foram alteradas pela inclusão de casca do grão de soja nas rações. No entanto, para a ingestão de extrato etéreo, FDN e amido, houve efeito linear dos níveis de casca do grão de soja. Para as digestibilidades da MS, MO, PB, CT, FDN, amido e para os NDT, foram observados efeitos quadráticos e a digestibilidade do extrato etéreo não foi alterada. A inclusão de casca do grão de soja em níveis de até 75% nas rações de cabritos melhora a digestibilidade e o valor energético das dietas, mantendo-se a viabilidade econômica. Abstract in english The objective of this study was to evaluate the dry matter and nutrient intake and digestibility and to estimate the energy value of diets with the inclusion of soybean hulls (0, 25, 50, 75 and 100%) replacement of ground corn in the diet of kids goats. The rations consisted of oat hay, ground corn and/or soybean hulls, soybean meal and mineral supplement. Five Saanen kid goats (32.44 ± 4.00 kg), housed in digestibility cages, in a 5 × 5 Latin square design were used. T (more) otal feces were collected with canvas bags. Each period consisted of 12 days, seven days to adapt to the rations and five days for collections. The intake of dry matter (DM), organic matter (OM), crude protein (CP), total carbohydrates (TC) and total digestible nutrients (TDN) were altered by the inclusion of soybean hulls in the rations. However, for the intakes of ether extract, NDF and starch there was a linear effect. Quadratic effects were observed for the digestibility of DM, OM, CP, TC, NDF, starch and the TDN but the ether extract digestibility was not altered. The inclusion of the soybean hulls up to 75% in the rations of kid goats improved digestibility, resulting in higher energy value with economic viability.

Genistein is a powerful antioxidant and plays a role in calcium and bone metabolism. We evaluated the efficacy of dietary supplementation with genistein on the nutrient use and mineral concentrations in tibia and serum of quails reared at high environmental temperature (34°C). Two hundred and forty Japanese quails (10 days old) were randomly assigned to 8 treatment groups consisting of 10 replicates of 3 birds. The birds were kept in a temperature-controlled room at 22°C (Thermoneutral, TN groups) or 34°C (for 8 h/d; 09.00 am-05.00 pm; Heat stress, HS groups). Birds were fed either a basal diet (TN and HS) or the basal diet supplemented with 200, 400 or 800 mg of genistein/kg of diet. Heat exposure decreased apparent nutrient digestibility and bone mineralization when the basal diet was fed (P<0.001). Apparent digestibility of dry matter (DM) (P<0.05), crude protein (CP) (P<0.05) and ash (P<0.01) was significantly improved by genistein supplementation. However, this improvement was not in direct proportion to increased doses of supplement since there was no difference when diets included either 400 or 800 mg genistein/kg of diet (P<0.05) in birds reared under heat stress. The amounts of Ca, P, Mg, Mn, Zn, Fe and Cu in the excreta decreased (P<0.01), while Ca, P, Mg, Mn, Zn and Cu concentrations in tibia ash increased in quails reared under heat stress conditions (P<0.01) with genistein supplementation. Ca and P concentrations in tibia ash were also increased in birds kept under thermoneutral conditions with genistein supplementation. Increased serum alkaline phosphatase activity (P<0.01) was associated with increasing dietary genistein in all groups. In conclusion, genistein supplementation to the basal diet improved digestibility of CP, DM and ash and levels of Ca and P and bone mineralization in quails reared under heat stress conditions.   

1. The objective of this study was to determine the influence of heat-treatment (autoclaving) on the utilisation by chicks of near-isogenic lines of faba beans that were either tannin-free (Winter-white or Spring-white) or had tannins in the seed coat (Winter-coloured or Spring-coloured). The effect of heat treatment on a common tannin-containing cultivar, Diana, was also studied. 2. The nitrogen-corrected apparent metabolisable energy (AMEn) values of diets containing 600 g faba beans/kg diet were affected by tanning content and autoclave treatment of faba beans, with 59% of total variance in AMEn being attributable to the effect of autoclaving. The AMEn values were 9% higher for chicks fed on the autoclaved compared with those fed on diets containing the raw faba beans, 5% higher for the near-isogenic faba beans with no tannins compared with those with tannins, and 4% higher for the Winter compared with the Spring cultivars. 3. The above study was carried out on droppings obtained by total collection. Similar but not identical trends were obtained when AMEn was calculated using the chromic oxide index method (r = 0.91). 4. Both autoclaving and the use of tannin-free faba beans improved the apparent protein digestibility (APD) of the diets by similar amounts (4% as determined by the total collection method and 6% as determined by the chronic oxide index method). 5. The digestibility of most amino acids either alone or together was affected by a cultivar x tannin x processing interaction. The cultivar by tannin interaction demonstrated that autoclaving increased the digestibility of amino acids to a greater degree when the tannin-containing (for example, 9% for lysine) than when the tannin-free faba beans (4% for lysine) were used in the diets. 6. The improvements in AMEn, APD and total amino acid digestibilities of faba beans following heat treatments ranged from 18% to 33%, 5% to 16% and 5% to 11%, respectively. The results demonstrate that the method of analysis can affect the values obtained but that they do not change the overall pattern of results. The results also suggest that, in most cases, more than half of the response to heat treatment is associated with the inactivation of tannins while the balance of the response is attributable to an effect of heat treatment on the non-tannin-containing factors. In summary, heat treatment can improve the utilisation of faba bean by chickens especially when they contain tannins. 7. Chicks, unlike rats, do not seem to adapt to tannins as the excretion of 3 amino acids that are the main constituents of a proline-rich protein were not affected by dietary tannins. PMID:9568305

Abstract in portuguese Subprodutos vegetais têm sido utilizados na dieta com a finalidade de melhorar o estado nutricional de populações desnutridas. Entretanto, os antinutrientes presentes nesses alimentos podem acarretar efeitos indesejáveis. Portanto, os teores de polifenóis, cianeto, saponinas, inibidor de tripsina, atividade hemaglutinante e a porcentagem da digestibilidade proteica in vitro de sementes de abóbora cruas e tratadas termicamente foram investigados com o objetivo de sel (more) ecionar o processamento que acarrete maior redução dos antinutrientes e maior digestibilidade proteica. Sementes da abóbora Cucurbita maxima foram, em quatro repetições, submetidas aos seguintes tratamentos: utilizadas na forma crua; cozidas em água em ebulição (AE) por três tempos: 5, 10 e 15 minutos; e cozidas no vapor por 10 minutos. Posteriormente foram liofilizadas, trituradas e armazenadas em temperatura ambiente até a realização das análises. Não houve diferença significativa, entre os tratamentos, quanto aos níveis de polifenóis. As sementes cruas apresentaram o maior teor de cianeto, o menor nível de inibidor de tripsina e a menor digestibilidade proteica. O cozimento em AE por 10 minutos acarretou o menor nível de saponinas e a maior digestibilidade proteica. Não foi detectada atividade hemaglutinante em nenhuma amostra. Conclui-se que o cozimento em AE por 10 minutos foi o que proporcionou melhores resultados. Abstract in english Vegetable subproducts have been used in diets with the purpose of improving the nutritional quality of undernourished populations. However, the antinutrients present in those foods can cause adverse health effects. Therefore, the contents of polyphenols, cyanide, saponins, trypsin inhibitor, hemaglutinin activity, and the percentage of the in vitro protein digestibility of raw and thermally treated pumpkin seeds were investigated with the objective of selecting the proces (more) sing that results in major antinutrient reduction and greater protein digestibility. Pumpkin seeds (Cucurbita maxima) were submitted to the following treatments, which were carried out in quadruplicate: used raw; boiled for 5, 10, and 15 minutes; and steamed for 10 minutes. Next, the seeds were freeze-dried, grinded, and stored at room temperature until the analyses were completed. There was no significant difference among the treatments as for the levels of polyphenols. The raw seeds showed the highest content of cyanide, smallest level of trypsin inhibitor, and smallest protein digestibility. The 10-minute boiling resulted in the lowest content of saponins and greatest protein digestibility. No Hemaglutinin activity was detected in the samples. It can be concluded that the 10-minute boiling was the treatment that produced better results.

Summary Switchgrass (Panicum virgatum L.) has been developed into a dedicated herbaceous bioenergy crop. Biomass yield is a major target trait for genetic improvement of switchgrass. microRNAs have emerged as a prominent class of gene regulatory factors that has the potential to improve complex traits such as biomass yield. A miR156b precursor was overexpressed in switchgrass. The effects of miR156 overexpression on SQUAMOSA PROMOTER BINDING PROTEIN LIKE (SPL) genes were revealed by microarray and quantitative RT-PCR analyses. Morphological alterations, biomass yield, saccharification efficiency and forage digestibility of the transgenic plants were characterized. miR156 controls apical dominance and floral transition in switchgrass by suppressing its target SPL genes. Relatively low level...

Whey proteins have been recognized as a source of nutrients for decades and recent advances in analytical and biochemical techniques have helped characterize their bioactive potentials. Several bioactive peptides are released by proteolysis during gastrointestinal digestion or fermentation by proteo...

Cystic fibrosis (CF) is a potentially life-threatening disease that causes thick, sticky mucus to build up in the lungs and digestive tract. Persons with cystic fibrosis need to eat high calorie and high protein ...

The amino acid profiles, modified essential amino acid (MEAA) indexes, and in vitro pepsin digestibilities were determined for single-cell protein (SCP) from certain industrially important lactobacilli. For the three parameters examined, substantial differences were seen between different Lactobacil...

Abstract Our study investigates biomarker responses and survival of Macoma nasuta exposed to sediments collected from six locations in northern San Francisco Bay. Biomarkers analyzed were stress proteins (hsp70) in gill, mantle and digestive gland, lysosomal mem...

Performance differences in protein and proteome characterization achieved by data-independent acquisition (DIA) LC/MS(E) and data-dependent acquisition (DDA) LC/MS/MS approaches were investigated. LC/MS(E) is a novel mode of generating product ion data for all coeluting precursors in parallel as opposed to LC/MS/MS where coeluting precursors must be serially fragmented one at a time. During LC/MS(E) analysis, alternating MS scans of "normal" and "elevated" collision energy are collected at regular intervals, providing nearly a 100% duty cycle for precursor detection and fragmentation because all precursors are fragmented across their full chromatographic elution profile. This is in contrast to DDA-based MS/MS where serial selection of precursor ions is biased toward interrogation and detection of the highest abundance sample components by virtue of the intensity-driven interrogation scheme employed. Both modes of acquisition were applied to a simple four-protein standard mixture with a 16-fold dynamic range in concentration, an in-gel digest of the Arabidopsis thaliana protein FLS2 purified by immunoprecipitation, and a solution-digested tomato leaf proteome sample. Dramatic improvement for individual protein sequence coverage was obtained for all three samples analyzed by the DIA approach, particularly for the lowest abundance sample components. In many instances, precursors readily detected and identified during DIA were either interrogated by MS/MS during DDA at inopportune points in their chromatographic elution profiles resulting in poor quality product ion spectra or not interrogated at all. Detailed evaluation of both DDA and DIA raw data and timing of the MS-to-MS/MS switching events clearly revealed the fundamental limitations of serial MS/MS interrogation and the advantages of parallel fragmentation by DIA for more comprehensive protein identification and characterization which holds promise for enhanced isoform and post-translational modification analysis. PMID:20450226

Metal-Coded Affinity Tags (MeCAT) reagents were devised for the absolute quantification of labeled proteins and peptides using inductively coupled plasma mass spectrometry (ICP-MS). After the recent publication of quantification approaches for digested proteins, this work presents a multidimensional strategy for the application of MeCAT to samples which require higher chromatographic resolution. Two-dimensional separations based on strong cation exchange (SCX) and reversed-phase (RP) chromatography, were used for the quantification of lysozyme, bovine serum albumin and transferrin after tryptic digestion. The elution protocols were optimized to improve the resolution of the MeCAT-labeled peptides which led to faster elutions in SCX and longer retention times in RP compared with unlabeled peptides. The optimized method provided enough resolution for the samples analyzed. Peptides losses during the whole procedure were studied. Although recoveries of greater than 90% were found in the RP dimension, important global losses in the two-dimensional offline approach forced us to use specific internal standards, in this case MeCAT-labeled standard peptides. External calibration and label-specific isotope dilution analysis (IDA) were tested and compared as possible quantification techniques. While both techniques showed accurate and precise determinations, the label-specific IDA technique resulted in more straightforward measurements and more affordable external calibrations. Finally, simultaneous quantification of three different samples labeled with different lanthanides was successfully performed demonstrating the potential of MeCAT combined with ICP-MS for multiplexing. Electrospray ionization mass spectrometry techniques provided the structural information needed for the identification of the labeled species. PMID:22707168

A-50 day feeding trial was carried out to determine effects of dietary bamboo charcoal (BC) on growth, nutrient utilization and ammonia nitrogen excretion of tiger puffer fish, Takifugu rubripes. Six levels of BC (0, 0.004, 0.01, 0.1, 1 and 4%) were supplemented to the basal diet and fed to fish (initial BW, 53±2 g) at 3% of body weight. At the end of the trial, body weight gain and specific growth rate of fish fed the diet supplemented with 4% BC were significantly higher than the other groups. Furthermore, 4% BC group showed significantly higher feed intake and feed efficiency and protein efficiency ratios than those of fish fed diet supplemented with 0% BC diet (control) group. In nutrient and dry matter digestibility of fish fed 4% BC diet was significantly higher than those fed 0 and 0.004% BC diets. Moreover, protein digestibilities of fish fed diets including 0.01%-4% BC diets were significantly higher than that of fish fed 0.004% BC and control diets. After termination of the rearing trial, ammonia nitrogen excretion rates were determined with fish of (BW 130±2 g). Fish fed 4% BC diet was significantly lower excretion rate than those fed 0.004% BC and control diets. These results indicated that diet with 4% BC improved the growth and nutrient utilization of juvenile tiger puffer under the conditions employed in this study.   

The aim of this study was to determine the antihypertensive effects of enzymatic hemp seed protein hydrolysate (HPH) and its peptide fractions. Hemp seed protein isolate was digested by the sequential action of pepsin and pancreatin to mimic gastrointestinal digestion in human beings. The resultant HPH was separated by membrane ultrafiltration into peptide fractions with different sizes (<1 and 1?3?kDa). The HPH led to significantly higher (P?P?P?

The objective of BIOVIRTA project is to develop technologies and practices with which digestates, originating from anaerobic digestion of different organic wastes and by-products can be refined to value-added and safe products for various end-uses. It is expected that the operational preconditions for biogas plants will be significantly enhanced when the end-products are proven safe and applicable. Selection of the raw materials for anaerobic co-digestion is the main operational strategy that could influence the nutrient content in the digestate. This has been clearly established in the laboratory and full-scale studies with various digestates originating from different raw materials. The nutrient content in the digestate also affects the opportunities to produce refined digestate products. In this project, the possibilities for several processing technologies, e.g. mechanical separation, stripping, and struvite production have been intensively evaluated for the production of different digestate products. Their mass balances have also been estimated. The feasibility for the use of the digestate products has been assessed based on their chemical and hygienic quality and for various end-uses, including as organic fertiliser and/or soil improver in crop production. The results of these field-experiments showed that the yield of barley fertilised with digestate products was comparable to inorganic fertilisers. (orig.)

Simulation studies for a full-scale anaerobic unit of a wastewater treatment plant (WWTP) were performed using the anaerobic digestion model no. 1 (ADM1). The anaerobic full-scale plant consists of one mesophilic and one thermophilic digester, operated in an anaerobic sequential batch reactor (ASBR) mode, and sludge enrichment reactors (SER) for each digester. The digesters are fed with a mixture of vegetable waste and process wastewater from the food factory. Characteristics such as COD(total), N(total) and NH(4)-N concentrations in the influent and effluent of the digester and SERs were measured and used for input fractionation. Parameters such as level, pH, biogas amount and composition in the digester were measured online and used for calibration. For simulation studies, different temperatures and operation modes with varying chemical oxygen demand (COD) input loads corresponding to feedstocks such as fruits, vegetables and grain were analysed and compared. Higher gas production and digestion efficiency in the thermophilic reactor and in shorter cycles were found and confirmed at full scale. Serial operation mode increased the gas production, but pH inhibition occurred earlier. Feeding only biosolids into digester I and the effluent of digester I together with process water into digester II further improved gas production in serial operation mode. PMID:22258689

Based on 300 scientific papers, the following bibliographical research deals with the fate of micro-pollutants (pathogens, heavy metals, organic pollutants) during anaerobic digestion. Different biological and chemical mechanisms allow organic compounds elimination, except from some Polycyclic Aromatic Hydrocarbons (PAHs) and heavy metals which are fixed to the solid biomass, permitting water contamination risks attenuation. Unlike mesophilic digestion, thermophilic digestion is a 'sanitation' process regarding pathogens elimination. However, mesophilic digestion offers an important reliability compared with competitive or complementary processes. In particular, energy recovery from anaerobic digestion allows temperature control and makes easier further sanitation heat treatments. In general, anaerobic digestion represents a tool which can be included in an organic waste treatment line assuming waste selection and good agricultural practices. Otherwise, sanitation problem is still badly handled by waste operators and constructors which have been consulted. Research orientations seem especially interesting in improving knowledge of real industrial processes performances. (author)

With global climate change, more and more attention has been paid to the development of bio-energy. Biogas fermentation, as a fairly mature technology of bio-matter energy transformation, has received considerable attention and experienced much development. How to improve the efficiency of biogas fermentation and promote its industrialization is a pressing issue. Anaerobic co-digestion is a simple, low-cost, and high-efficiency method for enhancing the efficiency of biogas fermentation, and received increasing attention from related researchers. This paper summarized the characteristics of various fermentation substrates, reviewed the research advances in the co-digestion of animal manure, sewage sludge, and industrial waste, with the focus on the advantages of co-digestion and the factors affecting the rate and efficiency of co-digestion, and prospected the future research of co-digestion and its application, aimed to provide theoretical guidance for the promotion and application of co-digestion techniques. PMID:23173482

The effects of four modified diets (gamma-irradiated, microwave-irradiated, probiotic-supplemented and carbohydrase-supplemented diets) were studied on digestive enzyme specific activities and growth performance quality of juvenile Siamese fighting fish (Betta splendens Regan, 1910) during 2weeks of critical and intensive rearing period. The modified procedures did not change biochemical compositions and gross energy of diets, but generally resulted in relatively higher in vitro digestibilities of protein and carbohydrate and fish survival rate, albeit insignificant. Only gamma irradiation significantly increased in vitro protein digestibility of the diet, and microwave irradiation increased starch gelatinization and water solubility (P<0.05). Fish fed microwave-treated diet showed highest...

System stability and performance of high-solids anaerobic co-digestion of dewatered sludge (DS) and food waste (FW) in comparison with mono digestions were investigated. System stability was improved in co-digestion systems with co-substrate acting as a diluting agent to toxic chemicals like ammonia or Na(+). For high-solids digestion of DS, the addition of FW not only improved system stability but also greatly enhanced volumetric biogas production. For high-solids digestion of FW, the addition of DS could reduce Na(+) concentration and help maintain satisfactory stability during the conversion of FW into biogas. System performances of co-digestion systems were mainly determined by the mixing ratios of DS and FW. Biogas production and volatile solids (VSs) reduction in digestion of the co-mixture of DS and FW increased linearly with higher ratios of FW. A kinetic model, which aimed to forecast the performance of co-digestion and to assist reactor design, was developed from long-term semi-continuous experiments. Maximum VS reduction for DS and FW was estimated to be 44.3% and 90.3%, respectively, and first order constant k was found to be 0.17d(-1) and 0.50d(-1), respectively. Experimental data of co-digestion were in good conformity to the predictions of the model. PMID:23177568

Abstract in portuguese Avaliaram-se os consumos, as digestibilidades ruminal e intestinal e as taxas de passagem e de digestão de nutrientes em bovinos alimentados com dietas constituídas de silagem de milho, cana-de-açúcar triturada e fornecida in natura, cana triturada e ofertada após 72 horas de armazenamento, cana-de-açúcar ensilada com 1 % de cal e sem tratamento e um mesmo concentrado fixado em 1% do peso corporal. Todos os volumosos foram corrigidos com ureia/sulfato de amônio pa (more) ra conterem 10% de proteína bruta. Utilizaram-se cinco bovinos fistulados no rúmen, com peso médio de 240 kg ± 15 kg, distribuídos em um quadrado latino 5 × 5. Foram realizadas coletas totais de fezes, abomasal e dois esvaziamentos pela manhã. Os animais alimentados com dietas à base de silagem de milho apresentaram maiores digestibilidades ruminal da proteína e intestinal do extrato etéreo, taxas de ingestão, passagem e de digestão da matéria seca, justificando os maiores consumos de matéria seca e fibra em detergente neutro corrigida para cinzas e proteína (FDNcp). As maiores taxas de passagem nos animais alimentados com dietas à base de cana-de-açúcar in natura justificam os maiores consumos de matéria seca e FDNcp em relação ao observado com o fornecimento de silagens de cana-de-açúcar. Animais consumindo dietas contendo silagem de milho apresentam maiores taxas de passagem da matéria seca e digestão da FDNcp. Dietas contendo cana-de-açúcar in natura, armazenada ou não, favorecem o consumo e a taxa de passagem da matéria seca, em relação a dietas com cana ensilada. O uso de cal na ensilagem não melhora a digestibilidade dos nutrientes nem a taxa de passagem da dieta. A cana-de-açúcar armazenada por 72 horas possui características digestíveis semelhantes às da cana-de-açúcar in natura. Abstract in english It was evaluated intake, rumen and intestinal digestibility and passage and digestion rates in bovines fed diets constituted of corn silage, crushed sugar cane and given fresh, crushed sugar cane and given after 72 hours of storage, ensiled sugar cane with 1% of calcium oxide and with no treatment and a same concentrate fixed at 1% of body weight. All roughage was corrected to contain 10% of crude protein. It was used five rumen-fistulated bovine with average weight of 24 (more) 0 ± 15 kg, distributed in a 5 × 5 Latin square. Abomasum and total fecal collection and two rumen evacuations were carried out in the morning. Animals fed corn silage based diet presented greater rumen digestibility of the protein and intestinal digestibility of the ether extract, greater intake and passage of dry matter, justifying greater intakes of dry matter and neutral detergent fiber corrected for protein and ash (NDFap). The greatest passage rates in animals fed fresh sugar cane based diet justify greater intakes of dry matter and NDFap in relation to the one observed with sugar cane silage supply. Animal consuming corn silage diets present greater dry matter passage rate and NDFap digestion. Diets with fresh sugar cane, stored or not, favor dry matter passage rate and intake, in relation to ensiled sugar cane. The use of calcium oxide in the ensilage does not improve nutrient digestibility neither passage rate of the diet. Sugar cane stored for 72 hours has digestible traits similar to the ones of fresh sugar cane.

The new regulations for sludge recycling to land in Britain will be implemented during 2003. The Regulations define two classes of bio solids, ''treated sludge'' and ''enhanced treated'' sludge. In the UK, mesophilic anaerobic digestion is predominantly used for treatment of sludge. Studies by UK Water Companies have established that a 1.5 log reduction can be achieved in the digestion process but a further period of secondary digestion Is required to achieve the necessary 2 log reduction and the MAC standard required by the Regulations. This paper describes several approaches by Thames Water to improve pathogen reduction of mesophilic anaerobically digested sludge. At one site with a population equivalent of 1.7 million a refurbishment programme enabled eight of the digesters to be operated at eight different operating regimes, with temperatures up to 38{sup C} and retention times from 12 to 19 days with the same feedstock. This site had no secondary digestion, and to construct secondary digestion for a site that produces 3,000 m3 of digested sludge per day would be extremely expensive. Therefore an exercise to optimise the pathogen reduction was begun to see if the normal 1.5 log reduction could be improved upon. The data collected showed that it was not achievable and an alternative strategy was required. In the UK, sludge digestion is operated in two stages, mesophilic anaerobic digestion (MAD) followed by secondary batch digestion. Mesophilic anaerobic digestion stabilizes sludge by destroying the organic solids and producing biogas whilst during the secondary batch digestion consolidation and further pathogen reduction occurs. An alternative approach was adopted where secondary batch digestion tanks were converted to run in a continuous node of operation. This resulted in reduction In volume required whilst maintaining good pathogen reduction performance. Another approach was to use a pre-treatment process in front of conventional mesophilic anaerobic digestion. Bench scale trials showed that short retention time acid phase digestion (APD), operating at high organic loading resulted in high VFA concentration. This proved to cause effective E.coli reduction. The combined process of APD and MAD produced a treated' product without the need for secondary digestion. Based on the result of this study a full-scale APD has been built and is undergoing commissioning at a 300,000 population equivalent STW.

The distribution of ribosomal protein binding sites on the 16S ribosomal RNA molecule has been analyzed by limited ribonuclease hydrolysis of RNA-protein complexes, as well as by the interaction of individual proteins with RNA fragments purified from partial enzymatic digests. Of the six 30S subunit...

at very high levels, greater than 50% of the total protein, and it is highly .... from pH 3-11, and the protein is stable at low and high salt concentrations. ... Interestingly, the OspA-257 protein is exceptionally resistant to digestion by trypsin and ...

This study was designed to clarify the influence of long-term enteral nutrition (EN) on the pharmacokinetics of digoxin. Rats were fed EN diets (semi-digested, digested, and elemental) for 4 weeks, then digoxin (0.05 mg/kg) was administered orally. The AUC(0-?) and k(a) of digoxin were significantly reduced in the semi-digested diet group versus the control, while the AUC(0-?) was significantly increased in the digested and elemental diet groups. The mRNA level of Slco1a4 was significantly reduced at the upper small intestine in all EN groups. Further, the expression levels of P-glycoprotein (P-gp) protein and Abcb1a mRNA were increased at the same site in all EN groups, and the increases were significant in the elemental diet group. Cyp3a2 protein and mRNA expressions were significantly reduced in the liver in the digested and elemental diet groups. Abcb1a mRNA was also significantly reduced in the kidney in these groups. These results indicate that the absorption kinetics at the small intestine is influenced by semi-digested diet, and the elimination kinetics in the liver and kidney are influenced by digested and elemental diet. Semi-digested diet also altered digoxin pharmacokinetics in humans. Thus, the effect of long-term EN on digoxin pharmacokinetics depended on the dietary components. PMID:22785356

The digestive process transforms nutrients and bioactive compounds contained in food to physiologically active compounds. In vitro digestion systems have proven to be powerful tools for understanding and monitoring the complex transformation processes that take place during digestion. Moreover, the investigation of the physiological effects of certain nutrients demands an in vitro digestive process that is close to human physiology. In this study, human digestion was simulated with a 3-step in vitro process that was validated in depth by choosing pasteurized milk as an example of a complex food matrix. The evolution and decomposition of the macronutrients was followed over the entire digestive process to the level of intestinal enterocyte action, using protein and peptide analysis by SDS-PAGE, reversed-phase HPLC, size exclusion HPLC, and liquid chromatography-MS. The mean peptide size after in vitro digestion of pasteurized milk was 5-6 amino acids (AA). Interestingly, mostly essential AA (93.6%) were released during in vitro milk digestion, a significantly different relative distribution compared to the total essential AA concentration of bovine milk (44.5%). All TG were degraded to FFA and monoacylglycerols. Herein, we present a human in vitro digestion model validated for its ability to degrade the macronutrients of dairy products comparable to physiological ranges. It is suited to be used in combination with a human intestinal cell culture system, allowing ex vivo bioavailability measurements and assessment of the bioactive properties of food components. PMID:22223575

Abstract in portuguese Avaliaram-se os efeitos dos níveis de lisina digestível da ração, com base no conceito de proteína ideal, no desempenho de alevinos de de tilápia-do-nilo (Oreochromis niloticus). Utilizaram-se 432 alevinos revertidos, linhagem tailandesa, com peso inicial de 1,12 ± 0,02 g, em delineamento inteiramente ao acaso, composto de 6 dietas, 6 repetições e 12 peixes por unidade experimental. Como tratamentos, avaliaram-se uma dieta basal com 29,12% de proteína bruta e 3. (more) 000 kcal de energia digestível/kg, suplementada com aminoácidos sintéticos, resultando em dietas com 0,95; 1,10; 1,25; 1,40; 1,55 e 1,70% de lisina digestível e relações mínimas entre metionina + cistina, treonina, triptofano, isoleucina e arginina com a lisina (66, 77, 23, 64 e 85%, respectivamente), com base em valores digestíveis. Os peixes foram mantidos em aquários de 130 litros, dotados de abastecimento de água, temperatura controlada e aeração individual, e alimentados à vontade em seis refeições diárias durante 30 dias. Avaliaram-se os parâmetros de desempenho, a composição corporal, a deposição de proteína e gordura corporais e a eficiência de retenção de nitrogênio dos peixes. A elevação do teor de lisina digestível na ração não influenciou a taxa de sobrevivência e o teor de gordura corporal dos peixes, mas melhorou de forma linear todos os demais parâmetros avaliados, com exceção da eficiência de utilização de lisina e a umidade corporal, que pioraram de forma quadrática e linear, respectivamente. O nível de 1,80% de lisina total (0,600% Mcal de ED) e o de 1,70% de lisina digestível (0,567% Mcal de ED) proporcionam os melhores resultados de desempenho e características de carcaça de alevinos de tilápia-do-nilo quando se utiliza o conceito de proteína ideal na formulação das rações experimentais. Abstract in english The effects of the digestible lysine level were assessed in feeds for Nile tilapia fingerlings (Oreochromis niloticus), based on the ideal protein concept. Four hundred and thirty two reverted fingerlings were used, average weight 1.12 ± 0.02 g, in a randomized complete design, consisting of 6 feeds, six replications and twelve fish per experimental unit. The diets consisted of a basal diet with 29.12% crude protein and 3,000 kcal/kg digestible energy, supplemented with (more) synthetic amino acids, resulting in six diets with 0.95; 1.10; 1.25; 1.40; 1.55 and 1.70% digestible lysine and minimum ratios between methionine plus cystine, threonine, thryptophan, isoleucine, arginine with the lysine (66, 77, 23, 64 and 85%, respectively), based on digestible values. The fish were maintained in 130 liter aquaria equipped with individual water and controlled temperature and aeration. The fish were fed to apparent satiation, six times a day, for 30 days. Growth performance, body composition, body protein and fat deposition and nitrogen retention efficiency of the fish were evaluated. The increase in the dietary digestible lysine did not affect the survival rate and body fat level of the fishes. However, there was linear improvement in all the other parameters assessed, except lysine use efficiency and the body humidity, that showed quadratic and lineardecline, respectively. The levels of 1.80 (0.600% Mcal of DE) total lysine and 1.70% (0.567% Mcal of DE) digestible lysine, respectively, result in the best performance and carcass characteristics of Nile tilapia fingerlings, when the ideal protein concept is used to formulate the experimental diets.

The purpose of this study was to increase the efficiency of anaerobic digestion of waste activated sludge (WAS). Either thermochemical or biological hydrolysis was used as a pretreatment and the effects of both were investigated and compared. Two different three-stage digestion systems showed improved performance, although thermochemical hydrolysis showed better results than biological hydrolysis in a bench-scale operation. After anaerobic digestion with thermochemical pretreatment, the total chemical oxygen demand (tCOD) reduction, volatile solid (VS) reduction, methane yield and methane biogas content were 88.9%, 77.5%, 0.52 m3/kg VS and 79.5%, respectively. These results should help in determining the best hydrolysis pretreatment process for anaerobic digestion and in improving the design and operation of the large-scale treatment of WAS by anaerobic digestion with hydrolysis systems.   

Background: Milk is a major constituent of small children’s diet. Milk allergy is also one of the most common allergies in small children. Prevention, treatment and general understanding of this allergy are therefore important. Methods: Intact BLG was digested in an in vitro model simulating the human gastro-duodenal digestion process. Four different fractions of BLG-digest was made, based on sizes of peptides or aggregates hereof. Intact BLG and the four fractions of BLG-digesta were characterized by protein chemical analyses. Brown Norway (BN) rats were immunised i.p. three times without the use of adjuvant with either PBS (control), 200 µg of intact BLG, 30 µg of intact BLG, 200 µg of digested BLG (with 30 µg of intact BLG), 200 µg of digested BLG, 200 µg of a fraction of large complexes or 200 µg of a fraction of small complexes (all three without intact BLG). Sera from BN rats were analysed for specific IgG and IgE responses and avidity of specific antibodies was measured. Results: Native BLG is relatively resistant to digestion. However, when first broken down to larger fragments these are rapidly digested to smaller peptides of sizes ? 4.5 kDa. The small peptides did aggregate to complexes of larger sizes. Specific antibody responses revealed that both the high (200 µg) and low (30 µg) amount of intact BLG had both immunogenic and allergenic sensitising capacity, while digested BLG had no sensitizing capacity. In contrast digested BLG and the fraction of large complexes retained their antibody binding capacity. Most importantly, while intact BLG showed a significant sensitising capacity when administered alone, the sensitising capacity of the intact BLG was significantly reduced when co-administered with digested BLG. Conclusion: Co-administration of intact and digested BLG reduced sensitising capacity of intact BLG, indicating induction of tolerance or other protective mechanism by the digested BLG.

Abstract in portuguese O experimento foi conduzido com os objetivos de avaliar o efeito da suplementação de fitase em dietas sobre a energia metabolizável (EMAn) e sobre os coeficientes de digestibilidade ileal aparente de matéria seca, proteína bruta, cálcio e fósforo e determinar a deposição de cinzas, cálcio e fósforo na tíbia de frangos de corte. Foram utilizados 350 frangos de corte machos Ross de 16 a 25 dias de idade, distribuídos num delineamento inteiramente ao acaso, com (more) cinco dietas e dez repetições de sete aves por unidade experimental. As dietas, à base de milho e de farelo de soja, foram formuladas considerando a disponibilidade de energia metabolizável, proteína bruta, lisina, cálcio e fósforo disponível, de acordo com a matriz nutricional da enzima fitase, e suplementadas com 0,5% de oxido crômico. As dietas foram: controle positivo; controle negativo 1; controle negativo 2; controle negativo 1 + 250 uft; controle negativo 2 + 500 uft. A suplementação de enzima fitase nos níveis de 250 e de 500 uft/kg de dieta melhorou os valores energéticos das dietas, que aumentaram, em média, 36 e 54 kcal/kg de MS, respectivamente. A utilização de fitase melhorou os coeficientes de digestibilidade da proteína bruta e do fósforo, cujos maiores valores foram obtidos com a suplementação de 500 uft/kg de ração. A suplementação de fitase melhorou o coeficiente de digestibilidade e a retenção de fósforo, reduzindo o fósforo excretado, e aumentando a composição de fósforo na tíbia das aves, principalmente nos frangos de corte alimentados com a dieta suplementada com fitase (500 uft/kg). A suplementação de fitase (500 uft/kg) melhora o coeficiente de digestibilidade da proteína bruta e do fósforo, melhora a retenção de fósforo e diminui a excreção de fósforo de frangos de corte. Abstract in english The experiment was carried out to evaluate the effect of phytase enzyme supplementation in diets on the metabolizable energy (ME) and on the apparent ileum digestibility coefficients of the dry matter, crude protein, calcium and phosphorous, and to determine the deposition of ashes, calcium and phosphorous on the tibia of broilers. It was used 350 Ross male broilers from 16 to 25 days of age distributed in a complete randomized design with five diets and ten replicates of (more) seven birds per each experimental unit. The diets which were corn and soybean meal based were formulated considering the availability of metabolizable energy, crude protein, lysine, calcium, and available phosphorus according to the nutritional matrix of phytase enzyme, and supplemented with 0.5% of chromium oxide. The diets were the following: positive control; negative control 1; negative control 2; negative control 1 + 250 ftu; negative control 2 + 500 ftu. The phytase enzyme supplementation at levels of 250 and 500 ftu/kg of diet improved the energetic values of the diets by 36 and 54 kcal/kg of dry matter, respectively. The use of phytase improved the digestibility coefficients of crude protein and phosphorus, whose highest values were obtained with supplementation of 500 ftu/kg of diet. The phytase supplementation improved coefficient of digestibility and phosphorous retention reducing excreted phosphorous and increasing composition of phosphorous in the tibia of the birds, mainly for the broilers fed diet supplemented with phytase (500 ftu/kg). The phytase supplementation (500 ftu/kg) improves the digestibility coefficients of crude protein and phosphorous, improves the retention of phosphorus and reduces phosphorus excretion of broilers.

Sep 24, 1991 ... Methods for producing oxygen from metal oxides bear- .... acid. ne ilmenite is digested an improvement upon the existing sulfate route to tita- ... conditions (and at titanium, aluminum and Chromium impurities from the ...

Abstract in portuguese Um ensaio de digestibilidade (experimento 1) foi conduzido para determinar os coeficientes de digestibilidade aparentes da matéria seca (CDMS), proteína bruta (CDPB), amido (CDAM) e energia bruta (CDEB) e o coeficiente de metabolização da energia bruta (CMEB) da silagem de grãos úmidos de milho (SGUM). Foram utilizados 12 suínos mestiços (Landrace, Large-White e Duroc) machos castrados, alojados em gaiolas de metabolismo, distribuídos em um delineamento experimen (more) tal inteiramente casualizado. O método utilizado foi o da coleta total de fezes e urina. Os valores de matéria seca digestível (MSD), proteína digestível (PD), amido digestível (AD), energia digestível (ED) e energia metabolizável (EM), na matéria natural (60,18% de MS), foram, respectivamente, 48,70; 3,77; 42,35%; 2.389 e 2.327 kcal/kg de SGUM. O experimento 2 foi conduzido para avaliar o desempenho de leitões e a viabilidade econômica da utilização das rações com diferentes níveis de substituição do milho seco por SGUM. Foram utilizados 48 suínos mestiços (Landrace, Large White e Duroc), distribuídos em um delineamento inteiramente casualizado, com seis repetições e dois animais por unidade experimental. Os tratamentos consistiram de uma ração à base de milho e farelo de soja e outras três com 33, 66 e 100% de substituição do milho seco por SGUM com base nos valores de energia digestível. Não houve efeito da inclusão de SGUM sobre o ganho de peso e o consumo de ração, porém ocorreu redução linear na conversão alimentar e no custo da ração por quilograma de peso vivo ganho. Os dados indicam que o milho seco pode ser totalmente substituído pela SGUM em rações para leitões em fase de creche, com melhora nos índices produtivos e econômicos. Abstract in english A digestibility assay was carried out to determine the dry matter apparent digestibility coefficients (DMDC), crude protein (CPDC), starch (SDC), gross energy (GEDC) and gross energy metabolization coefficient (GEMC) of high moisture corn silage (HMCS). Twelve crossbred (Landrace x Large-White x Duroc) castrated males were allotted to metabolism cages, in a completely randomized design. The total feces and urine collection method was used. The values of digestible dry mat (more) ter (DDM), digestible protein (DP), digestible starch (DS), digestible energy (DE), and metabolizable energy (ME) of HMCS were 48.70, 3.77, 42.35%, and 2,389 and 3,327 kcal/kg, respectively, based on natural matter (60.18% DM). The experiment 2 was carried out to evaluate piglet performance and economic viability of diets with different substitution levels of dry yellow corn by HMCS. Forty-eight cross-breed (Landrace x Large-White x Duroc) piglets were used. The piglets were divided into four treatments in a completely randomized design, with six experimental units and two piglets per experimental unit. The treatments consisted of a basal corn-soybean meal diet and three diets with increasing dry yellow corn substitution by HMCS levels (33, 66 and 100%), based on the digestible energy content of dry yellow corn and HMCS. There was no effect of increasing levels of HMCS on daily weight gain and daily feed intake. Linear reduction on feed conversion and diet cost per kilogram of weight gain was observed. Data indicate that dry corn can be completely replaced by HMCS on piglets diets, with improvement on performance and economic index.

Watermelon (Citrullus lanatus) seed meal contains significant amount of extractable protein which can be used as nutritional and functional ingredients in food formulations. Alkali (0.1 M) and NaCl (0.5 M) were used to prepare protein isolates and concentrates from the defatted watermelon seed meals. Protein isolates reported protein yield of 35.15?38.27% and protein content (79.05?83.79%) which was significantly (p?0.05) higher than the protein concentrates. SDS-PAGE of protein isolates and concentrates showed major polypeptides in the range of 74.72?110.42 kDa. Also, in vitro pepsin digestibility showed that most of the proteins were readily digested within 30 min of hydrolysis. Amino acids were dominated by arginine, aspartic, and glutamic acid. DSC results indicated that protein concen...

Digestion of blood meal proteins by midgut proteases provides anautogenous mosquitoes with the nutrients required to complete the gonotrophic cycle. Inhibition of protein digestion in the midgut of blood feeding mosquitoes could therefore provide a strategy for population control. Based on recent reports indicating that the mechanism and regulation of protein digestion in blood fed female Aedes aegypti mosquitoes is more complex than previously thought, we used a robust RNAi knockdown method to investigate the role of four highly expressed midgut serine proteases in blood meal metabolism. We show by Western blotting that the early phase trypsin protein (AaET) is maximally expressed at 3 h post-blood meal (PBM), and that AaET is not required for the protein expression of three late phase se...

Accumulation of acids in anaerobic digesters after organic overload can inhibit or stop CH4 production. Therefore, methods to reduce acid concentrations would be helpful. One potential method to improve recovery involves bioaugmentation, addition of specific microorganisms to improve performance. In this study, transiently overloaded digesters were bioaugmented with a propionate-degrading enrichment culture in an effort to decrease recovery time. Biomass samples from 14 different, full-scale anaerobic digesters were screened for specific methanogenic activity (SMA) against propionate; the microbial communities were also compared. SMA values spanned two orders of magnitude. Principal component analysis of denaturing gradient gel electrophoresis (DGGE) banding patterns for a functional gene ...

The biology of Bracon hebetor Say (Hymenoptera: Braconidae) reared on fifth instars of Anagasta kuehniella (Zeller) (Lepidoptera: Pyralidae) (natural diet) and in vitro (artificial diet) was evaluated. Data on the number of instars, development time and food intake were collected, and histochemical tests were conducted to detect proteins and lipids in the parasitoid's digestive tract. The data disclosed differences that can help to improve artificial rearing of B. hebetor. B. hebetor had three instars in both diets, but the developmental time on the artificial diets was prolonged due to the increase in larval and pupal development times. Larvae grew faster on the natural host and required a lower food intake (2.7 microl) as compared to that required by the larvae feeding on the artificial diet (3.8 microl). Analysis of diet protein content and host hemolymph and the observations on the parasitoid larvae gut content indicated altogether the artificial diets requires the addition of others sources of proteins and lipids to improve the overall nutrition quality of the in vitro rearing system for this ectoparasitoid. PMID:17348133

Abstract in english This study aimed to evaluate the nutrient digestibility of roughages in horses with total feces collection and mobile bags. Two trials were carried out simultaneously. The first trial evaluated the digestibility of nutrients of coastcross hay (Cynodon dactylon cv. coastcross) with total feces collection. The second trial assessed the digestibility of nutrients of alfalfa hay (Medicago sativa), peanut (Arachis pintoi) and coastcross hay with mobile bags. This trial was con (more) ducted with gastric insertions of nylon bags every 12 hours, and each bag contained 663 mg of feed samples in a proportion of 17 mg DM/cm². Feces and bags were collected directly from the stall floor immediately after excretion. There was no difference between the digestibility of dry matter, crude protein, carbohydrates and hydrolysable carbohydrates of coastcross hay estimated with feces collection and mobile bags. Forage peanut showed high nutrients digestibility, with values close to those observed with alfalfa, indicating potential for use in diets for horses.

Developing healthy products requires in-depth knowledge of digestion. This study focuses on lipid digestion in relation to emulsion properties typically followed by pH-stat. Although this is a fast and easy method to follow the overall digestion, it provides no details on lipid digestion products. Thus, the aims of the present study were to use gas chromatography (GC) to determine all products present during lipolysis, i.e. monoglycerides (MG), diglycerides (DG) and triglycerides (TG), and to compare this method with the pH-stat method for free fatty acids (FFA). Fine, medium and coarse emulsions stabilized with two different emulsifiers (whey protein isolate (WPI) or gum arabic) were digested under in vitro intestinal conditions. Although the amount of FFA increased for both methods for W...

Summary Background Food allergies are a public health issue of growing concern, with peanuts in particular being associated with severe reactions. The peanut allergen, Ara h 1, belongs to the cupin plant food allergen family, which, unlike other structural families, appears to be broken down rapidly following gastrointestinal digestion. Objective Using Ara h 1 as a model allergen, the ability of digested protein to sensitize has been investigated. Methods Ara h 1 was purified from whole roasted peanuts. Intact Ara h 1 was digested in an in vitro model, simulating the human gastrointestinal digestion process. Digestion products were analysed for peptide sizes and their ability to aggregate. Brown Norway (BN) rats, used as an animal model, were immunized with purified intact Ara h 1 or the g...

This study was carried out to evaluate the effect of gamma irradiation on nutrient digestibility of either soy-based or milk-based diet for specific pathogen-free (SPF) mini-pigs. Gamma irradiation of the diets was done at dosage of 10 kGy with 60Co whereas autoclaving was executed at 121 °C for 20 min. Apparent crude protein digestibilities of gamma irradiated diets were higher (pDigestibilities of dry matter, gross energy and total carbohydrate in the irradiated diet were higher than those of the autoclaved diet. From the results of nutrient digestibility of mini-pig diets in this study, 10 kGy gamma radiation was suggested as a convenient diet radicidation method that can minimize the decrease in nutrient digestibility on feeding to SPF mini-pigs.

1. The effects of field bean tannin-containing hulls (T-hulls), non-tannin hulls (NT-hulls) and tannin extract on starch digestibilities and TMEn of triticale and semipurified starches from triticale and field beans were evaluated with adult cockerels and 3-week-old-chicks. 2. For both cockerels and chicks, the digestibility and TMEn of semipurified starches from triticale were higher than those from beans. Starch digestibilities of triticales (range 99.1 to 97.7%), of semipurified starches from triticales (range 96.5 to 89.9%) and from field beans (range 75.4 to 71.6%) were similar for both cockerels and chicks. 3. The addition of NT-hulls improved, in general, the digestibility of semipurified starches for both chicks and cockerels, which suggests that fibre improves the digestion of semipurified starches. 4. The effects of tannins of T-hulls on semipurified starch from beans and from triticale were different. Tannins always decreased the digestibility and TMEn of semipurified starch from field beans but only decreased the digestibility and TMEn of semipurified starch from triticale when fed to chicks, but not when fed to cockerels. 5. The addition of tannin extract always decreased the digestibility of semipurified starches by a greater amount than T-hulls, which supports the idea that the effect of tannins depends on the quantity of tannin ingested. PMID:8062111

The crude protein hydrolysates from aqueous extract of velvet antler (AEVA) were prepared by simulated gastrointestinal digestion (SGI, pepsin-pancreatin) using pancreatin-pepsin, alcalase and neutrase. The resulting hydrolysates were separated by sequential ultrafiltration into four fractions. The antioxidant activities of peptide fractions were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferric reducing antioxidant power (FRAP), 2,2'-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging and Fe(2+)-chelating assays. Results showed that the hydrolysate prepared by SGI had a low degree of hydrolysis, which was significantly improved with altered proteases, such as pancreatin-pepsin and alcalase. Antioxidant activities of peptide fractions varied with molecular weight (MW) and the enzyme used. Generally, low-MW peptide fractions had higher ABTS radical scavenging activity and Fe(2+)-chelating ability, and high-MW peptide fractions were more effective in DPPH radical scavenging activity and reducing power. PMID:22224289

To investigate the influences of alkaline pretreatment on anaerobic digestion (AD) and sludge dewaterability after AD, waste activated sludge was adjusted to different pH values (8, 9, 10, 11, 12) and placed at ambient temperature for 24 hr. The samples were then adjusted to the initial pH and subjected to 25 days of AD. The results showed that, when compared with the control (pH 6.8), total suspended solids (TSS) and volatile suspended solids (VSS) reduction following pretreatment at pH 9-11 increased by 10.7%-13.1% and 6.5%-12.8%, respectively, while biogas production improved by 7.2%-15.4%. Additionally, significant enhancement of sludge dewaterability after AD occurred when pretreatment at pH 8-9 was conducted. The proteins and carbohydrates transferred from the pellet and tightly boun...

Barley is a major feed source for livestock in the western regions of North America. Feed quality of beef cattle has been neglected as a selection criterion because of lack of understanding of the feed characteristics that could be responsive to selection and would improve feedlot performance. A Steptoe ?? Morex population was planted in irrigated and rain-fed environments, and collected data were used to evaluate the genetic variation in dry matter and starch digestibilities, acid detergent fiber, protein and starch contents, and to map quantitative trait loci controlling the variation in these traits. Transgressive genotypes indicate the wide genetic variation of these traits. High heritability estimates for these traits suggest that early selection for these traits during breeding wou...

In order to improve the efficiency and evaluate the feasibility of anaerobic digestion for treatment of soybean protein wastewater. The stability and performance of the Up-Flow Anaerobic Sludge Blanket (UASB) process was investigated at different organic loading rates (OLRS) and hydraulic retention times over 200 days. When chemical oxygen demand (COD) reached maximum, the loading rate was adjusted in a small way and indicators such as VFA, pH and COD in effluent as well as gas production are observed. These experimental results clearly showed that, the most proper corresponding organic loading rate (OLR) and hydraulic retention time were 6 kg/ (m3.d) (COD = 6000 mg/L) and 24 h respectively. Up to 85% of COD was removed and the CH4 production rate of 3.2 m3/(m3.d) was obtained. The produced biogas contained 72% of CH4. In the mean time, anaerobic sludge multiplies more faster and exiguous particles appeared. Granules with diameter 1-3 mm.

The objective of this study was to evaluate the effects of LaCl3 supplementation on rumen fermentation, urinary excretion of purine derivatives and feed digestibility in the total tract of steers. Eight ruminally cannulated Simmental steers (420+-20kg) were used in a replicated 4x4 Latin square experiment. The treatments were control (without LaCl3); La-low; La-medium and La-high with 450, 900 and 1800mg LaCl3 per steer per day, respectively. Diet consisted of 600g/kg corn stover and 400g/kg concentrate (dry matter [DM] basis). Dry matter intake (averaged 9kg/day) was restricted to a maximum of 90% of ad libitum intake. Ruminal pH (range of 6.59-6.42) was quadratically (PIn situ ruminal neutral detergent fibre (aNDF) degradation of corn stover was improved but the crude protein (CP) degrad...

ABSTRACT: Nutritionally enhanced beans (NEB) with more Fe and Zn than conventional beans (CB) and nutritionally enhanced maize (NEM) with more tryptophan and lysine than conventional maize (CM) were developed as part of a crop-biofortification strategy to improve human nutrition. Proxy measures were used to assess Fe and Zn bioavailability and protein digestibility of a bean recipe (frijol sancochado) and a maize-milk recipe (mazamorra) prepared with enhanced or conventional crops in Colombia. Fe concentration was similar in the cooked NEB and CB and in NEM and CM (P? 0.05); in vitro Fe dialyzability was similar in cooked NEB (9.52%) and CB (9.72%) and greater for NEM (37.01%) than CM (32.24%). Zn concentration was higher in the uncooked and cooked NEB than in the CB (P < 0.05); phytate...

Integration of metabolic and immune responses during animal development ensures energy balance, permitting both growth and defense. Disturbed homeostasis causes organ failure, growth retardation, and metabolic disorders. Here, we show that the Drosophila melanogaster activating transcription factor 3 (Atf3) safeguards metabolic and immune system homeostasis. Loss of Atf3 results in chronic inflammation and starvation responses mounted primarily by the larval gut epithelium, while the fat body suffers lipid overload, causing energy imbalance and death. Hyperactive proinflammatory and stress signaling through NF-?B/Relish, Jun N-terminal kinase, and FOXO in atf3 mutants deregulates genes important for immune defense, digestion, and lipid metabolism. Reducing the dose of either FOXO or Relish normalizes both lipid metabolism and gene expression in atf3 mutants. The function of Atf3 is conserved, as human ATF3 averts some of the Drosophila mutant phenotypes, improving their survival. The single Drosophila Atf3 may incorporate the diversified roles of two related mammalian proteins. PMID:22851689

In order to obtain an improved understanding of the assembly of the bacterial photosynthetic apparatus, we have conducted a proteomic analysis of pigment-protein complexes isolated from the purple bacterium Rhodobacter sphaeroides undergoing acclimation to reduced incident light intensity. Photoheterotrophically growing cells were shifted from 1,100 to 100?W/m2 and intracytoplasmic membrane (ICM) vesicles isolated over 24-h were subjected to clear native polyacrylamide gel electrophoresis. Bands containing the LH2 and reaction center (RC)-LH1 complexes were excised and subjected to in-gel trypsin digestion followed by liquid chromatography (LC)-mass spectroscopy (MS)/MS. The results revealed that the LH2 band contained distinct levels of the LH2-? and -? polypeptides encoded by the two puc...

Infantile colic, the cause of 10???20% of all early paediatrician visits, can lead to parental exhaustion and stress. A systematic review was conducted to examine whether dietary change provides an effective therapy for infantile colic. Six databases were searched from 1960, and 24 studies selected for inclusion. In breastfed infants, evidence suggests that a hypoallergenic maternal diet may be beneficial for reducing symptoms of colic. In formula-fed infants, colic may improve after changing from a standard cow???s milk formula to either a hydrolysed protein formula or a soy-based formula. Fibre-supplemented formulae had no effect. Removal of poorly digested carbohydrates from the infant???s diet has promise, but additional clinical studies must be conducted before a recommendation can be...

Costelytra zealandica larvae are pests of New Zealand pastures causing damage by feeding on the roots of grasses and clovers. The major larval protein digestive enzymes are serine proteases (SPs), which are targets for disruption in pest control. An expressed sequence tag (EST) library from healthy, third instar larval midgut tissue was constructed and analysed to determine the composition and regulation of proteases in the C. zealandica larval midgut. Gene mining identified three trypsin-like and 11 chymotrypsin-like SPs spread among four major subgroups. Representative SPs were examined by quantitative PCR and enzyme activity assayed across developmental stages. The serine protease genes examined were expressed throughout feeding stages and downregulated in nonfeeding stages. The study will improve targeting of protease inhibitors and bacterial disruptors of SP synthesis. PMID:18477240

The present study was conducted to investigate the effects of varying dietary fat levels (3%-10%) on the digestibilities of crude protein, crude fat (CF), nitrogen-free extract and ash at different sites of fistulized chicken intestines. Chickens were fistulized to either the middle part of the jejunum (MJ), the distal end of the jejunum (DJ), the middle part of the ileum, the distal end of the ileum or the distal end of the rectum. Intestinal digesta were collected from each site of intestine, and contents of crude protein, crude fat, nitrogen-free extract and ash were measured. The true digestibility of crude protein in intestinal digesta at MJ in the 10% CF group was significantly lower than that in other groups. The digestibility of crude fat in intestinal digesta at MJ in the 10% CF group was also significantly lower than that in other groups. The digestibility of nitrogen-free extract at MJ and DJ in the 10% CF group was significantly lower than that in other groups. There were no significant differences in digestibility of ash among groups. These results clearly demonstrate that dietary fat levels influence the digestibility of protein, fat, and carbohydrate at MJ in chicken.   

The effect of halofuginone (Halo) on established fibrosis in older mdx dystrophic muscle was investigated. Mice (8 to 9 mo) treated with Halo (or saline in controls) for 5, 10, or 12 wk were assessed weekly for grip strength and voluntary running. Echocardiography was performed at 0, 5, and 10 wk. Respiratory function and exercise-induced muscle damage were tested. Heart, quadriceps, diaphragm, and tibialis anterior muscles were collected to study fibrosis, collagen I and III expression, collagen content using a novel collagenase-digestion method, and cell proliferation. Hepatocyte growth factor and alpha-smooth muscle actin proteins were assayed in quadriceps. Halo decreased fibrosis (diaphragm and quadriceps), collagen I and III expression, collagen protein, and smooth muscle actin content after 10 wk treatment. Muscle-cell proliferation increased at 5 wk, and hepatocyte growth factor increased by 10 wk treatment. Halo markedly improved both cardiac and respiratory function and reduced damage and improved recovery from exercise. The overall impact of established dystrophy and dysfunction in cardiac and skeletal muscles was reduced by Halo treatment. Marked improvements in vital-organ functions implicate Halo as a strong candidate drug to reduce morbidity and mortality in Duchenne muscular dystrophy. PMID:18263710

Two trials were conducted to test the hypotheses that (i) feeding small amount of a tanniniferous shrub foliage (Acacia cyanophylla Lindl., acacia) increases the proportion of rumen undegradable protein, and consequently benefits growth performance in Barbarine lamb; and (ii) such positive effect depends on the timing of feeding tannin source (i.e. acacia) relative to protein source (soya bean meal, SBM). Total (TT) and condensed tannin (CT) concentrations in air-dried acacia leaves used in this study averaged 29 g tannic acid and 48 g leucocyanidin equivalents per kg dry matter (DM), respectively. In trial 1, rumen fistulated ewes received oaten hay (hay) ad libitum and 200 g SBM (D1), D1 and 100 g acacia fed with the SBM (D2, mixed strategy) or as D2, but the SBM fed 1 h later than acacia when acacia was consumed completely (D3, sequential strategy). Hay intake, diet digestibility, rumen fermentation parameters (pH, ammonia nitrogen (NH{sub 3}-N) and total volatile fatty acids) and in situ degradation of SBM nitrogen were similar between D1 and D2 (P > 0.05). However, the sequential strategy (D3) resulted in efficient use of N as reflected by the decrease of crude protein digestibility (CPD), plasma urea, NH{sub 3}-N concentration and in situ degradation of SBM nitrogen. In trial 2, four groups each of six Barbarine lambs (initial LW 35.3 {+-} 3.7 kg) received for 90 days: hay ad libitum and 200 g SBM (D1), D1 and 20 g polyethylene glycol (PEG, MW 4000) mixed with SBM (D2), D1 and 100 g acacia with the SBM fed 1 h later when acacia was completely consumed (sequential strategy) (D3) or D3 and 20 g PEG fed with the SBM (D4). Polyethylene glycol was here used to deactivate tannins. Hay intake and DM, organic matter and neutral detergent fibre digestibility were similar among dietary treatment (P > 0.05). However, supplementing lambs with SBM and acacia without PEG (D3) resulted in a significant decrease (P < 0.001) of CPD (0.664 versus 0.597, respectively for D1 and D3). Lambs given D1, D2 and D4 had similar growth rates (38.8-48.3 g/day) (P > 0.05). However, those supplemented with acacia without PEG (D3) had highest (P < 0.001) daily gain (66.7 g/day). The results of this study support the hypothesis that acacia could be used advantageously to improve sheep performance provided that appropriate TT to protein ratio is respected and the sequential strategy is adopted. (author)

Twenty nursing Awassi ewes (BW?=?50?±?2.35 kg, age?=?4.5?±?1.2 years) with their lambs were used to evaluate the effects of feeding calcium salts in lactation diets on performance and pre-weaning growth of their lambs. Treatments were 0% calcium salts (CON) or 5% calcium salts (FAT). At the end of the study, a digestibility experiment was performed. Milk yield was greater (P?ewes fed the FAT diet than the CON diet. Milk composition was similar (P?>?0.05) between diets. However, milk energy value (kcal/day) tended to be greater (P?=?0.07) for the FAT diet than the CON diet. Concentrations of milk C18:1c9 and C20:0 were greater (P?ewes fed the FAT diet than the CON diet. However, concentration of trans-10, cis-12 CLA was lower (P?=?0.05) in the FAT diet than in the CON diet. No differences in feed intake and body weight change were detected between diets. Digestibility of dry matter, organic matter, crude protein, ether extract, neutral detergent fiber, and acid detergent fiber were similar (P?>?0.05) for diets. For lambs, weaning weight was not affected by treatments. However, average daily gain and total gain were greater (P?=?0.053) for the FAT diet than the CON diet. Results suggest that supplementing lactating ewes with calcium salts at the beginning of lactation phase improves daily milk yield of ewes and pre-weaning growth of their lambs with no major negative impact on feed intake and digestibility. PMID:21448779

Measurements were made of biogas yields from anaerobic digestion of various crops and organic wastes in 20-litre continuous digesters at 35 degrees C and at various loading rates and retention times. With a loading rate of 2.5 kg TS/cubic m digester/day and a retention time of 20 days, the mean volumes of biogas (in litres) and methane contents (% methane) obtained from each kilogram of TS added to the digester were as follows: banana (fruit plus stem) 938(53), potato waste (peelings plus rejects 820(50), meat processing waste (minced paunch contents, intestines, hearts, and lungs) 603(59), kale (whole plant) 545(53), pasture grass (ryegrass plus clover) 498(56), pressed lucerne (residue after extraction of protein) 487(63), oats 476(54), lucerne 460(56), poultry manure 439(57), maize 406(57), synthetic garbage (minced paper, food scraps, and garden rubbish) 383(48), ground barley straw 285(54), newspaper 243(52), and chopped ryegrass straw 177(62). Biogas yields per kilogram of total solids decreased as the loading rate increased. Continuous digestion was more stable than batch digestion, but biogas yields obtained by both methods were very similar. Highly digestible materials could be continuously digested, whereas they could not be batch digested. The high biogas yields obtained from digestion of banana and potato wastes resulted from almost complete destruction of volatile solids and represented respectively 99% and 95% conversion of the energy in the original material into methane. Biogas yields from continuous digestion were closely related to the proportion of soluble cell contents in the respective materials. 24 references.

There is emerging interest in the impact of food structure on lipid digestion and its relationship to human nutrition. The objective of this study was to investigate the influence of heteroaggregation of lipid droplets on their potential biological fate using a simulated gastrointestinal tract (GIT). At neutral pH, a highly viscous "mixed emulsion" was formed by mixing anionic ?-lactogobulin (?-Lg) coated lipid droplets with cationic lactoferrin (LF) coated lipid droplets due to electrostatic attraction. We compared the behavior of ?-Lg-emulsions, LF-emulsions and mixed emulsions under in vitro oral, gastric, and small intestinal conditions. In the oral stage, the ?-Lg emulsion and mixed emulsion were stable but the LF emulsion aggregated, which was attributed to electrostatic interactions with mucin. In the gastric stage, extensive droplet aggregation occurred in all three emulsions, which was attributed to proteolysis of adsorbed proteins by pepsin, as well as the influence of high acidity and ionic strength on electrostatic interactions. Despite the differences in the initial compositions and microstructures of the three emulsions, we did not observe an appreciable difference in the rate or extent of their lipid digestion in the small intestine. Qualitatively similar results were obtained using a simple GIT model (small intestine only) and the full GIT model (oral, gastric, and small intestine). The knowledge gained from this study will be useful for the creation of functional foods to improve health and well-being. PMID:22790379

The weight-of-evidence, case-by-case approach is considered the most appropriate way of assessing the allergenicity of genetically modified (GM) food and feed. This scientific opinion discusses various aspects to increase the strength and accuracy of this approach, including the latest developments pertaining to clinical aspects of allergic reactions, structural aspects of GM food and feed and in silico approaches, as well as IgE binding studies and cell-based methods, profiling techniques and animal models. In this context, conclusions and recommendations are provided to update and complement current risk assessment strategies for the allergenicity assessment of newly expressed protein(s) and whole GM food and feed. In summary, it is recommended that with regard to the search for sequence homology and structural similarities, the local alignment method with a known allergen with a threshold of 35% sequence identity over a window of at least 80 amino acids is considered a minimal requirement. When IgE bindingtests are considered necessary, e.g. when there is sequence homology and/or structure similarity with known allergens, the use of individual sera from allergic individuals rather than pooled sera is recommended. In addition to the pepsin resistance test, it is recommended that the resistance to digestion of the newly expressed proteins is evaluated using other in vitro digestibility tests mimicking physiological conditions of humans. Finally, when the recipient of the introduced gene is allergenic, in order to compare the allergenicty of the whole GM plant with that of its appropriate comparator(s), it is recommended that relevant characterised endogenous allergens are included in the comparative compositional analysis of the GM plant and its appropriate comparator(s). Proposals for the use of additional testing that may improve the weight-of-evidence approach and suggestions for further evaluation of new promising methods that are as yet in an early phase of development are also addressed.

Abstract in english An experiment was conducted to study ileal digestibility of nutrients and to verify the ability of broilers to select feed in order to meet their requirements for protein and energy. The treatments consisted of six diets: R+S: free-choice feeding with rice bran (energy) and soybean meal (protein); C+G: free-choice feeding with corn (energy) and corn gluten meal (protein); R+G: free-choice feeding with rice bran (energy) and corn gluten meal (protein); C+S: free-choice fee (more) ding with corn (energy) and soybean meal (protein); R+C+G+S: free-choice feeding with rice bran and corn (energy) and corn gluten meal and soybean meal (protein); and BD: basal diet represented by a complete diet composed of 63% corn and 33% soybean meal. The results indicated that the adjustment to nutritional requirements does not depend only on the ability of birds to select feed. It might also depend on intake and ingredient quality, since some ingredients did not provide a balanced amount of nutrients. The birds were able to fulfill their requirements for maintenance, that is, they consumed the minimum amount of amino acids (g per day) for maximum growth. The free-choice group with corn gluten meal as the protein source had the worst performance, which indicated that this feed is not recommended as a primary source of amino acids for broilers. The C+G diet presented the highest digestibility coefficient of dry matter and crude protein, whereas the C+S diet resulted in the highest digestibility coefficient of ether extract and nitrogen-free extract, indicating that diet digestibility was affected by the type of feed used as energy and protein sources. In general, the high digestibility values indicate that broilers are able to efficiently digest and absorb the supplied feed.

Mass spectrometry-based multiple reaction monitoring (MRM) quantitation of proteins can dramatically impact the discovery and quantitation of biomarkers via rapid, targeted, multiplexed protein expression profiling of clinical samples. A mixture of 45 peptide standards, easily adaptable to common plasma proteomics work flows, was created to permit absolute quantitation of 45 endogenous proteins in human plasma trypsin digests. All experiments were performed on simple tryptic digests of human EDTA-plasma without prior affinity depletion or enrichment. Stable isotope-labeled standard peptides were added immediately following tryptic digestion because addition of stable isotope-labeled standard peptides prior to trypsin digestion was found to generate elevated and unpredictable results. Proteotypic tryptic peptides containing isotopically coded amino acids ([13C6]Arg or [13C6]Lys) were synthesized for all 45 proteins. Peptide purity was assessed by capillary zone electrophoresis, and the peptide quantity was determined by amino acid analysis. For maximum sensitivity and specificity, instrumental parameters were empirically determined to generate the most abundant precursor ions and y ion fragments. Concentrations of individual peptide standards in the mixture were optimized to approximate endogenous concentrations of analytes and to ensure the maximum linear dynamic range of the MRM assays. Excellent linear responses (r > 0.99) were obtained for 43 of the 45 proteins with attomole level limits of quantitation (<20% coefficient of variation) for 27 of the 45 proteins. Analytical precision for 44 of the 45 assays varied by <10%. LC-MRM/MS analyses performed on 3 different days on different batches of plasma trypsin digests resulted in coefficients of variation of <20% for 42 of the 45 assays. Concentrations for 39 of the 45 proteins are within a factor of 2 of reported literature values. This mixture of internal standards has many uses and can be applied to the characterization of trypsin digestion kinetics and plasma protein expression profiling because 31 of the 45 proteins are putative biomarkers of cardiovascular disease.

Abstract in portuguese A farinha de folhas de mandioca apresenta baixa digestibilidade, mesmo possuindo um teor relativamente elevado em proteínas, principalmente, devido à presença de substâncias como os polifenóis. Visando melhorar o aproveitamento protéico desta farinha, empregaram-se três solventes (água, etanol 50mL/100mL e hidróxido de amônio 1mol/L) para remover os polifenóis. Folhas maduras de mandioca foram coletadas na fase vegetativa, em três repetições, colocadas em ba (more) ndejas de papel e secas à sombra sobre bancadas de madeira, em recinto fechado e arejado, em temperatura ambiente. Após secagem, retiraram-se os pecíolos e as folhas foram moídas e passadas em peneira de 40mesh. A farinha foi submetida, antes e após a remoção dos polifenóis, às análises de umidade, fibra detergente neutra (FDN), fibra detergente ácida (FDA), açúcares totais, proteína bruta, vitamina C total, beta-caroteno, cianeto, inibidor de tripsina, polifenóis e digestibilidade protéica in vitro. Após remoção dos polifenóis, houve diminuição dos teores de açúcares totais, vitamina C total, inibidor de tripsina e polifenóis e aumento de FDN, FDA, proteína bruta, beta-caroteno e digestibilidade protéica in vitro. Dos solventes empregados para remover polifenóis, o hidróxido de amônio foi o mais eficaz, com índice de remoção de 94%, seguido pelo etanol (83%) e água (65%). A digestibilidade da proteína in vitro aumentou em 74%, quando o solvente empregado na remoção dos polifenóis foi o hidróxido de amônio. Abstract in english Even featuring a relatively high level in proteins, the flour of cassavaleaves presents low digestibility, mainly, due to the presence of such substances as polyphenols. Seeking to improve the protein availability of such flour, three solvents (water, ethanol 50mL/100mL and ammonium hydroxide 1mol/L) were used for the removal of the polyphenols. Mature leaves of cassava were picked in phase of vegetative development, in three repetitions, they were placed in paper trays a (more) nd dried under shadow, on a wood bench, in a shut and airy place, at room temperature. After drying, the petioles were removed and the leaves were ground and sieved using 40-mesh sieve. The flour was submitted, before e after removal of polyphenols, to the analyses of moisture, neutral detergent fiber (NDF), acid detergent fiber (ADF), total sugars, crude protein, vitamin total C, beta-carotene, cyanide, trypsin inhibitor, polyphenols and in vitro protein digestibility. After the removal of the polyphenols, there was a decrease in the levels of total sugars, vitamin total C, trypsin inhibitor and polyphenols and an increase in the levels of NDF, ADF, crude protein, beta-carotene and in vitro protein digestibility. Of the solvents employed in the removal the polyphenols, the ammonium hydroxide was the most effective, with index of removal of 94%, followed by the ethanol (83%) and water (65%). The in vitro protein digestibility increased of 74%, when the solvent employed in the removal of the polyphenols was the ammonium hydroxide.

To compare the nutrient digestibility of soybean meal (SM) and pigeon pea seed meal (PM) as well as morphological intestinal alterations in piglets fed them, three pigs per group were randomly selected at the end of the feeding experiment for ten days. Growth performance was higher in the SM group than in the PM group (p<0.05). The digestibility of crude protein, crude fat and crude fiber was 80.6%, 23.6% and 52.4% in the SM group, while in the PM group, values of 49.8%, 23.6% and 43.2% were observed, respectively. Digestible energy was 3.26 kcal g-1 in SM and 3.17 kcal g-1 in PM. It was concluded that the digestibility of PM was lower than that of SM; almost half of the protein in PM was digested. Dietary treatments had no effect on length of each small intestinal segment and weight of visceral organs (small intestine, liver, heart, spleen, kidney, stomach and lung) except the decreased kidney weight in the PM group (p<0.05). The epithelial cells on the jejunal villi showed a dome-like shape in the SM group, but they were a flat shape in the PM group. The present digestion trial and histological intestinal data suggest that the intestinal digestive and absorptive functions are much more atrophied in the PM group than in the SM group, and demonstrate that histological intestinal alterations might be well related with the intestinal functions.