MRM validation of targeted nonglycosylated peptides from N-glycoprotein biomarkers using direct trypsin digestion of undepleted human plasma.

PubMed

Lee, Ju Yeon; Kim, Jin Young; Cheon, Mi Hee; Park, Gun Wook; Ahn, Yeong Hee; Moon, Myeong Hee; Yoo, Jong Shin

2014-02-26

A rapid, simple, and reproducible MRM-based validation method for serological glycoprotein biomarkers in clinical use was developed by targeting the nonglycosylated tryptic peptides adjacent to N-glycosylation sites. Since changes in protein glycosylation are known to be associated with a variety of diseases, glycoproteins have been major targets in biomarker discovery. We previously found that nonglycosylated tryptic peptides adjacent to N-glycosylation sites differed in concentration between normal and hepatocellular carcinoma (HCC) plasma due to differences in steric hindrance of the glycan moiety in N-glycoproteins to tryptic digestion (Lee et al., 2011). To increase the feasibility and applicability of clinical validation of biomarker candidates (nonglycosylated tryptic peptides), we developed a method to effectively monitor nonglycosylated tryptic peptides from a large number of plasma samples and to reduce the total analysis time with maximizing the effect of steric hindrance by the glycans during digestion of glycoproteins. The AUC values of targeted nonglycosylated tryptic peptides were excellent (0.955 for GQYCYELDEK, 0.880 for FEDGVLDPDYPR and 0.907 for TEDTIFLR), indicating that these could be effective biomarkers for hepatocellular carcinoma. This method provides the necessary throughput required to validate glycoprotein biomarkers, as well as quantitative accuracy for human plasma analysis, and should be amenable to clinical use. Difficulties in verifying and validating putative protein biomarkers are often caused by complex sample preparation procedures required to determine their concentrations in a large number of plasma samples. To solve the difficulties, we developed MRM-based protein biomarker assays that greatly reduce complex, time-consuming, and less reproducible sample pretreatment steps in plasma for clinical implementation. First, we used undepleted human plasma samples without any enrichment procedures. Using nanoLC/MS/MS, we targeted

Digestibility of Glyoxal-Glycated β-Casein and β-Lactoglobulin and Distribution of Peptide-Bound Advanced Glycation End Products in Gastrointestinal Digests.

PubMed

Zhao, Di; Li, Lin; Le, Thao T; Larsen, Lotte Bach; Su, Guoying; Liang, Yi; Li, Bing

2017-07-19

This work reports the influence of glyoxal (GO)-derived glycation on the gastrointestinal enzymatic hydrolysis of β-lactoglobulin and β-casein. Reduced digestibility of glycated proteins was found in both gastric and intestinal stage. Distribution of Maillard reaction products in digests with different molecular weight ranges was investigated subsequently. The colorless and brown MRPs largely presented in the digests smaller than 20 kDa. However, the resistance of fluorescent advanced glycation end products (AGEs) to enzymatic hydrolysis gradually increased during glycation, rendering fluorescent AGEs largely present in the digests larger than 20 kDa. No free N (ε)-carboxymethyllysine (CML) was detected in digests. The relative amount of CML in digests larger than 1 kDa was higher than that of Lys, demonstrating the hindrance of CML to enzymatic hydrolysis. This study highlights the resistance of GO-derived AGEs to digestive proteases via blockage of tryptic cleavage sites or steric hindrance, which is a barrier to the absorption of dietary AGEs.

Can electromagnetic fields influence the structure and enzymatic digest of proteins? A critical evaluation of microwave-assisted proteomics protocols

PubMed Central

Damm, Markus; Nusshold, Christoph; Cantillo, David; Rechberger, Gerald N.; Gruber, Karl; Sattler, Wolfgang; Kappe, C. Oliver

2012-01-01

This study reevaluates the putative advantages of microwave-assisted tryptic digests compared to conventionally heated protocols performed at the same temperature. An initial investigation of enzyme stability in a temperature range of 37–80 °C demonstrated that trypsin activity declines sharply at temperatures above 60 °C, regardless if microwave dielectric heating or conventional heating is employed. Tryptic digests of three proteins of different size (bovine serum albumin, cytochrome c and β-casein) were thus performed at 37 °C and 50 °C using both microwave and conventional heating applying accurate internal fiber-optic probe reaction temperature measurements. The impact of the heating method on protein degradation and peptide fragment generation was analyzed by SDS-PAGE and MALDI-TOF-MS. Time-dependent tryptic digestion of the three proteins and subsequent analysis of the corresponding cleavage products by MALDI-TOF provided virtually identical results for both microwave and conventional heating. In addition, the impact of electromagnetic field strength on the tertiary structure of trypsin and BSA was evaluated by molecular mechanics calculations. These simulations revealed that the applied field in a typical laboratory microwave reactor is 3–4 orders of magnitude too low to induce conformational changes in proteins or enzymes. PMID:22889711

Characterization of on-target generated tryptic peptides from Giberella zeae conidia spore proteins by means of matrix-assisted laser desorption/ionization mass spectrometry.

PubMed

Dong, Hongjuan; Marchetti-Deschmann, Martina; Allmaier, Günter

2014-01-01

Traditionally characterization of microbial proteins is performed by a complex sequence of steps with the final step to be either Edman sequencing or mass spectrometry, which generally takes several weeks or months to be complete. In this work, we proposed a strategy for the characterization of tryptic peptides derived from Giberella zeae (anamorph: Fusarium graminearum) proteins in parallel to intact cell mass spectrometry (ICMS) in which no complicated and time-consuming steps were needed. Experimentally, after a simple washing treatment of the spores, the aliquots of the intact G. zeae macro conidia spores solution, were deposited two times onto one MALDI (matrix-assisted laser desorption ionization) mass spectrometry (MS) target (two spots). One spot was used for ICMS and the second spot was subject to a brief on-target digestion with bead-immobilized or non-immobilized trypsin. Subsequently, one spot was analyzed immediately by MALDI MS in the linear mode (ICMS) whereas the second spot containing the digested material was investigated by MALDI MS in the reflectron mode ("peptide mass fingerprint") followed by protonated peptide selection for MS/MS (post source decay (PSD) fragment ion) analysis. Based on the formed fragment ions of selected tryptic peptides a complete or partial amino acid sequence was generated by manual de novo sequencing. These sequence data were used for homology search for protein identification. Finally four different peptides of varying abundances have been identified successfully allowing the verification that our desorbed/ionized surface compounds were indeed derived from proteins. The presence of three different proteins could be found unambiguously. Interestingly, one of these proteins is belonging to the ribosomal superfamily which indicates that not only surface-associated proteins were digested. This strategy minimized the amount of time and labor required for obtaining deeper information on spore preparations within the

Preparation of open tubular capillary columns by in situ ring-opening polymerization and their applications in cLC-MS/MS analysis of tryptic digest.

PubMed

Wang, Hongwei; Yao, Yating; Li, Ya; Ma, Shujuan; Peng, Xiaojun; Ou, Junjie; Ye, Mingliang

2017-08-01

An open tubular (OT) column (25 μm i.d.) was prepared by in situ ring-opening polymerization of octaglycidyldimethylsilyl polyhedral oligomeric silsesquioxanes (POSS-epoxy) with 4-aminophenyl disulfide (APDS) in a binary porogenic system of ethanol/H 2 O. It was found that porogenic composition played an important role in the formation of OT stationary phases. The ratio of ethanol/H 2 O at 6/1 (v/v) would lead to the fabrication of hybrid monoliths, while the ratio of ethanol/H 2 O at 13/1 (v/v) would result in the synthesis of OT phases. In addition, the effects of precursor content and reaction duration on the thickness of OT stationary phases were investigated. Either lower precursor content or shorter reaction duration would produce thinner layer of OT column. The repeatability of OT columns was evaluated through relative standard deviation (RSD%) with benzene as the analyte. The run-to-run, column-to-column and batch-to-batch repeatabilities were 1.7%, 4.8% and 5.6%, respectively, exhibiting satisfactory repeatability of the OT column. Then tryptic digest of mouse liver proteins was used to evaluate the performance of the resulting OT columns (25 μm i.d. × 2.5 m in length) by cLC-MS/MS analysis, demonstrating their potential in proteome analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

The NISTmAb tryptic peptide spectral library for monoclonal antibody characterization.

PubMed

Dong, Qian; Liang, Yuxue; Yan, Xinjian; Markey, Sanford P; Mirokhin, Yuri A; Tchekhovskoi, Dmitrii V; Bukhari, Tallat H; Stein, Stephen E

2018-04-01

We describe the creation of a mass spectral library composed of all identifiable spectra derived from the tryptic digest of the NISTmAb IgG1κ. The library is a unique reference spectral collection developed from over six million peptide-spectrum matches acquired by liquid chromatography-mass spectrometry (LC-MS) over a wide range of collision energy. Conventional one-dimensional (1D) LC-MS was used for various digestion conditions and 20- and 24-fraction two-dimensional (2D) LC-MS studies permitted in-depth analyses of single digests. Computer methods were developed for automated analysis of LC-MS isotopic clusters to determine the attributes for all ions detected in the 1D and 2D studies. The library contains a selection of over 12,600 high-quality tandem spectra of more than 3,300 peptide ions identified and validated by accurate mass, differential elution pattern, and expected peptide classes in peptide map experiments. These include a variety of biologically modified peptide spectra involving glycosylated, oxidized, deamidated, glycated, and N/C-terminal modified peptides, as well as artifacts. A complete glycation profile was obtained for the NISTmAb with spectra for 58% and 100% of all possible glycation sites in the heavy and light chains, respectively. The site-specific quantification of methionine oxidation in the protein is described. The utility of this reference library is demonstrated by the analysis of a commercial monoclonal antibody (adalimumab, Humira®), where 691 peptide ion spectra are identifiable in the constant regions, accounting for 60% coverage for both heavy and light chains. The NIST reference library platform may be used as a tool for facile identification of the primary sequence and post-translational modifications, as well as the recognition of LC-MS method-induced artifacts for human and recombinant IgG antibodies. Its development also provides a general method for creating comprehensive peptide libraries of individual proteins.

The NISTmAb tryptic peptide spectral library for monoclonal antibody characterization

PubMed Central

Dong, Qian; Liang, Yuxue; Yan, Xinjian; Markey, Sanford P.; Mirokhin, Yuri A.; Tchekhovskoi, Dmitrii V.; Bukhari, Tallat H.; Stein, Stephen E.

2018-01-01

ABSTRACT We describe the creation of a mass spectral library composed of all identifiable spectra derived from the tryptic digest of the NISTmAb IgG1κ. The library is a unique reference spectral collection developed from over six million peptide-spectrum matches acquired by liquid chromatography-mass spectrometry (LC-MS) over a wide range of collision energy. Conventional one-dimensional (1D) LC-MS was used for various digestion conditions and 20- and 24-fraction two-dimensional (2D) LC-MS studies permitted in-depth analyses of single digests. Computer methods were developed for automated analysis of LC-MS isotopic clusters to determine the attributes for all ions detected in the 1D and 2D studies. The library contains a selection of over 12,600 high-quality tandem spectra of more than 3,300 peptide ions identified and validated by accurate mass, differential elution pattern, and expected peptide classes in peptide map experiments. These include a variety of biologically modified peptide spectra involving glycosylated, oxidized, deamidated, glycated, and N/C-terminal modified peptides, as well as artifacts. A complete glycation profile was obtained for the NISTmAb with spectra for 58% and 100% of all possible glycation sites in the heavy and light chains, respectively. The site-specific quantification of methionine oxidation in the protein is described. The utility of this reference library is demonstrated by the analysis of a commercial monoclonal antibody (adalimumab, Humira®), where 691 peptide ion spectra are identifiable in the constant regions, accounting for 60% coverage for both heavy and light chains. The NIST reference library platform may be used as a tool for facile identification of the primary sequence and post-translational modifications, as well as the recognition of LC-MS method-induced artifacts for human and recombinant IgG antibodies. Its development also provides a general method for creating comprehensive peptide libraries of individual

Biphasic microreactor for efficient membrane protein pretreatment with a combination of formic acid assisted solubilization, on-column pH adjustment, reduction, alkylation, and tryptic digestion.

PubMed

Zhao, Qun; Liang, Yu; Yuan, Huiming; Sui, Zhigang; Wu, Qi; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

2013-09-17

Combining good dissolving ability of formic acid (FA) for membrane proteins and excellent complementary retention behavior of proteins on strong cation exchange (SCX) and strong anion exchange (SAX) materials, a biphasic microreactor was established to pretreat membrane proteins at microgram and even nanogram levels. With membrane proteins solubilized by FA, all of the proteomics sample processing procedures, including protein preconcentration, pH adjustment, reduction, and alkylation, as well as tryptic digestion, were integrated into an "SCX-SAX" biphasic capillary column. To evaluate the performance of the developed microreactor, a mixture of bovine serum albumin, myoglobin, and cytochrome c was pretreated. Compared with the results obtained by the traditional in-solution process, the peptide recovery (93% vs 83%) and analysis throughput (3.5 vs 14 h) were obviously improved. The microreactor was further applied for the pretreatment of 14 μg of membrane proteins extracted from rat cerebellums, and 416 integral membrane proteins (IMPs) (43% of total protein groups) and 103 transmembrane peptides were identified by two-dimensional nanoliquid chromatography-electrospray ionization tandem mass spectrometry (2D nano-LC-ESI-MS/MS) in triplicate analysis. With the starting sample preparation amount decreased to as low as 50 ng, 64 IMPs and 17 transmembrane peptides were identified confidently, while those obtained by the traditional in-solution method were 10 and 1, respectively. All these results demonstrated that such an "SCX-SAX" based biphasic microreactor could offer a promising tool for the pretreatment of trace membrane proteins with high efficiency and throughput.

Blending protein separation and peptide analysis through real-time proteolytic digestion.

PubMed

Slysz, Gordon W; Schriemer, David C

2005-03-15

Typical liquid- or gel-based protein separations require enzymatic digestion as an important first step in generating protein identifications. Traditional protocols involve long-term proteolytic digestion of the separated protein, often leading to sample loss and reduced sensitivity. Previously, we presented a rapid method of proteolytic digestion that showed excellent digestion of resistant and low concentrations of protein without requiring reduction and alkylation. Here, we demonstrate on-line, real-time tryptic digestion in conjunction with reversed-phase protein separation. The studies were aimed at optimizing pH and ionic strength and the size of the digestion element, to produce maximal protein digestion with minimal effects on chromatographic integrity. Upon establishing optimal conditions, the digestion element was attached downstream from a capillary C4 reversed-phase column. A four-protein mixture was processed through the combined system, and the resulting peptides were analyzed on-line by electrospray mass spectrometry. Extracted ion chromatograms for protein chromatography based on peptide elution were generated. These were shown to emulate ion chromatograms produced in a subsequent run without the digestion element, based on protein elution. The methodology will enable rapid and sensitive analysis of liquid-based protein separations using the power of bottom-up proteomics methodologies.

Tryptic peptides of canine thyroglobulin reactive with sera of patients with canine hypothyroidism caused by autoimmune thyroiditis.

PubMed

Lee, J-Y; Uzuka, Y; Tanabe, S; Takasawa, T; Sarashina, T; Nachreiner, R F

2004-10-01

Canine thyroglobulin (cTg) was treated with trypsin at a ratio of trypsin to cTg of 1:100 (w/w). Tryptic peptides of cTg were analysed by Western immunoblotting for their reactivity to serum thyroglobulin autoantibodies (TgAA) from patients with TgAA-positive hypothyroidism and normal individuals. The sera of patients with TgAA-positive hypothyroidism reacted with several peptides: 43, 32.5 and 31 kDa; the sera of normal individuals did not bind these tryptic peptides. Some of the TgAA-positive sera of patients reacted with 25 kDa peptide in addition to three tryptic peptides above. This experiment was the first report about antigenic epitopes of cTg. These small tryptic peptides recognized by TgAA may be related with the induction of TgAA and may be useful as markers for autoimmune thyroid diseases in dog.

The unique peptidome: Taxon-specific tryptic peptides as biomarkers for targeted metaproteomics.

PubMed

Mesuere, Bart; Van der Jeugt, Felix; Devreese, Bart; Vandamme, Peter; Dawyndt, Peter

2016-09-01

The Unique Peptide Finder (http://unipept.ugent.be/peptidefinder) is an interactive web application to quickly hunt for tryptic peptides that are unique to a particular species, genus, or any other taxon. Biodiversity within the target taxon is represented by a set of proteomes selected from a monthly updated list of complete and nonredundant UniProt proteomes, supplemented with proprietary proteomes loaded into persistent local browser storage. The software computes and visualizes pan and core peptidomes as unions and intersections of tryptic peptides occurring in the selected proteomes. In addition, it also computes and displays unique peptidomes as the set of all tryptic peptides that occur in all selected proteomes but not in any UniProt record not assigned to the target taxon. As a result, the unique peptides can serve as robust biomarkers for the target taxon, for example, in targeted metaproteomics studies. Computations are extremely fast since they are underpinned by the Unipept database, the lowest common ancestor algorithm implemented in Unipept and modern web technologies that facilitate in-browser data storage and parallel processing. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Identification of Alternative Splice Variants Using Unique Tryptic Peptide Sequences for Database Searches.

PubMed

Tran, Trung T; Bollineni, Ravi C; Strozynski, Margarita; Koehler, Christian J; Thiede, Bernd

2017-07-07

Alternative splicing is a mechanism in eukaryotes by which different forms of mRNAs are generated from the same gene. Identification of alternative splice variants requires the identification of peptides specific for alternative splice forms. For this purpose, we generated a human database that contains only unique tryptic peptides specific for alternative splice forms from Swiss-Prot entries. Using this database allows an easy access to splice variant-specific peptide sequences that match to MS data. Furthermore, we combined this database without alternative splice variant-1-specific peptides with human Swiss-Prot. This combined database can be used as a general database for searching of LC-MS data. LC-MS data derived from in-solution digests of two different cell lines (LNCaP, HeLa) and phosphoproteomics studies were analyzed using these two databases. Several nonalternative splice variant-1-specific peptides were found in both cell lines, and some of them seemed to be cell-line-specific. Control and apoptotic phosphoproteomes from Jurkat T cells revealed several nonalternative splice variant-1-specific peptides, and some of them showed clear quantitative differences between the two states.

Short communication: Tryptic β-casein hydrolysate modulates enteric nervous system development in primary culture.

PubMed

Cossais, F; Clawin-Rädecker, I; Lorenzen, P C; Klempt, M

2017-05-01

The intestinal tract of the newborn is particularly sensitive to gastrointestinal disorders, such as infantile diarrhea or necrotizing colitis. Perinatal development of the gut also encompasses the maturation of the enteric nervous system (ENS), a main regulator of intestinal motility and barrier functions. It was recently shown that ENS maturation can be enhanced by nutritional factors to improve intestinal maturation. Bioactivity of milk proteins is often latent, requiring the release of bioactive peptides from inactive native proteins. Several casein-derived hydrolysates presenting immunomodulatory properties have been described recently. Furthermore, accumulating data indicate that milk-derived hydrolysate can enhance gut maturation and enrichment of milk formula with such hydrolysates has recently been proposed. However, the capability of milk-derived bioactive hydrolysate to target ENS maturation has not been analyzed so far. We, therefore, investigated the potential of a recently described tryptic β-casein hydrolysate to modulate ENS growth parameters in an in vitro model of rat primary culture of ENS. Rat primary cultures of ENS were incubated with a bioactive tryptic β-casein hydrolysate and compared with untreated controls or to cultures treated with native β-casein or a Prolyve β-casein hydrolysate (Lyven, Colombelles, France). Differentiation of enteric neurons and enteric glial cells, and establishment of enteric neural network were analyzed using immunohistochemistry and quantitative PCR. Effect of tryptic β-casein hydrolysate on bone morphogenetic proteins (BMP)/Smad pathway, an essential regulator of ENS development, was further assessed using quantitative PCR and immunochemistry. Tryptic β-casein hydrolysate stimulated neurite outgrowth and simultaneously modulated the formation of enteric ganglia-like structures, whereas native β-casein or Prolyve β-casein hydrolysate did not. Additionally, treatment with tryptic bioactive �

NEW SCX PEPTIDE ELUTION SCORE FOR PH/SALT-GRADIENT SCX CHROMATOGRAPHY IN 2D-NANO-LC/MSMS ANALYSIS OF PROTEIN DIGESTS

EPA Science Inventory

A new automated 2D-(SCX/RP)-nano-LC/MSMS method was developed. Separation of the peptides in the first LC dimension was the main focus of this work, and it was optimized using human serum albumin (HSA) and human lung cell lysate tryptic digests. Samples were reduced and alkylated...

The primary structure of aspartate aminotransferase from pig heart muscle. Partial sequences determined by digestion with thermolysin and elastase

PubMed Central

Bossa, Francesco; Barra, Donatella; Carloni, Massimo; Fasella, Paolo; Riva, Francesca; Doonan, Shawn; Doonan, Hilary J.; Hanford, Robin; Vernon, Charles A.; Walker, John M.

1973-01-01

Peptides produced by thermolytic digestion of aminoethylated aspartate aminotransferase and of the oxidized enzyme were isolated and their amino acid sequences determined. Digestion by elastase of the carboxymethylated enzyme gave peptides representing approximately 40% of the primary structure. Fragments from these digests overlapped with previously reported sequences of peptides obtained by peptic and tryptic digestion (Doonan et al., 1972), giving ten composite peptides containing 395 amino acid residues. The amino acid composition of these composite peptides agrees well with that of the intact enzyme. Confirmatory results for some of the present data have been deposited as Supplementary Publication 50018 at the National Lending Library for Science and Technology, Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973) 131, 5. PMID:4748834

Examining Troughs in the Mass Distribution of All Theoretically Possible Tryptic Peptides

PubMed Central

Nefedov, Alexey V.; Mitra, Indranil; Brasier, Allan R.; Sadygov, Rovshan G.

2011-01-01

This work describes the mass distribution of all theoretically possibly tryptic peptides made of 20 amino acids, up to the mass of 3 kDa, with resolution of 0.001 Da. We characterize regions between the peaks of the distribution, including gaps (forbidden zones) and low-populated areas (quiet zones). We show how the gaps shrink over the mass range, and when they completely disappear. We demonstrate that peptide compositions in quiet zones are less diverse than those in the peaks of the distribution, and that by eliminating certain types of unrealistic compositions the gaps in the distribution may be increased. The mass distribution is generated using a parallel implementation of a recursive procedure that enumerates all amino acid compositions. It allows us to enumerate all compositions of tryptic peptides below 3 kDa in 48 minutes using a computer cluster with 12 Intel Xeon X5650 CPUs (72 cores). The results of this work can be used to facilitate protein identification and mass defect labeling in mass spectrometry-based proteomics experiments. PMID:21780838

A Straightforward and Highly Efficient Precipitation/On-pellet Digestion Procedure Coupled to a Long Gradient Nano-LC Separation and Orbitrap Mass Spectrometry for Label-free Expression Profiling of the Swine Heart Mitochondrial Proteome

PubMed Central

Duan, Xiaotao; Young, Rebecca; Straubinger, Robert M.; Page, Brian J.; Cao, Jin; Wang, Hao; Yu, Haoying; Canty, John M.; Qu, Jun

2009-01-01

For label-free expression profiling of tissue proteomes, efficient protein extraction, thorough and quantitative sample cleanup and digestion procedures, as well as sufficient and reproducible chromatographic separation, are highly desirable but remain challenging. However, optimal methodology has remained elusive, especially for proteomes that are rich in membrane proteins, such as the mitochondria. Here we describe a straightforward and reproducible sample preparation procedure, coupled with a highly selective and sensitive nano-LC/Orbitrap analysis, which enables reliable and comprehensive expression profiling of tissue mitochondria. The mitochondrial proteome of swine heart was selected as a test system. Efficient protein extraction was accomplished using a strong buffer containing both ionic and non-ionic detergents. Overnight precipitation was used for cleanup of the extract, and the sample was subjected to an optimized 2-step, on-pellet digestion approach. In the first step, the protein pellet was dissolved via a 4 h tryptic digestion under vigorous agitation, which nano-LC/LTQ/ETD showed to produce large and incompletely cleaved tryptic peptides. The mixture was then reduced, alkylated, and digested into its full complement of tryptic peptides with additional trypsin. This solvent precipitation/on-pellet digestion procedure achieved significantly higher and more reproducible peptide recovery of the mitochondrial preparation, than observed using a prevalent alternative procedure for label-free expression profiling, SDS-PAGE/in-gel digestion (87% vs. 54%). Furthermore, uneven peptide losses were lower than observed with SDS-PAGE/in-gel digestion. The resulting peptides were sufficiently resolved by a 5 h gradient using a nano-LC configuration that features a low-void-volume, high chromatographic reproducibility, and an LTQ/Orbitrap analyzer for protein identification and quantification. The developed method was employed for label-free comparison of the

The on-bead digestion of protein corona on nanoparticles by trypsin immobilized on the magnetic nanoparticle.

PubMed

Hu, Zhengyan; Zhao, Liang; Zhang, Hongyan; Zhang, Yi; Wu, Ren'an; Zou, Hanfa

2014-03-21

Proteins interacting with nanoparticles would form the protein coronas on the surface of nanoparticles in biological systems, which would critically impact the biological identities of nanoparticles and/or result in the physiological and pathological consequences. The enzymatic digestion of protein corona was the primary step to achieve the identification of protein components of the protein corona for the bottom-up proteomic approaches. In this study, the investigation on the tryptic digestion of protein corona by the immobilized trypsin on a magnetic nanoparticle was carried out for the first time. As a comparison with the usual overnight long-time digestion and the severe self-digestion of free trypsin, the on-bead digestion of protein corona by the immobilized trypsin could be accomplished within 1h, along with the significantly reduced self-digestion of trypsin and the improved reproducibility on the identification of proteins by the mass spectrometry-based proteomic approach. It showed that the number of identified bovine serum (BS) proteins on the commercial Fe3O4 nanoparticles was increased by 13% for the immobilized trypsin with 1h digestion as compared to that of using free trypsin with even overnight digestion. In addition, the on-bead digestion of using the immobilized trypsin was further applied on the identification of human plasma protein corona on the commercial Fe3O4 nanoparticles, which leads the efficient digestion of the human plasma proteins and the identification of 149 human plasma proteins corresponding to putative critical pathways and biological processes. Copyright © 2014 Elsevier B.V. All rights reserved.

Highly Efficient Proteolysis Accelerated by Electromagnetic Waves for Peptide Mapping

PubMed Central

Chen, Qiwen; Liu, Ting; Chen, Gang

2011-01-01

Proteomics will contribute greatly to the understanding of gene functions in the post-genomic era. In proteome research, protein digestion is a key procedure prior to mass spectrometry identification. During the past decade, a variety of electromagnetic waves have been employed to accelerate proteolysis. This review focuses on the recent advances and the key strategies of these novel proteolysis approaches for digesting and identifying proteins. The subjects covered include microwave-accelerated protein digestion, infrared-assisted proteolysis, ultraviolet-enhanced protein digestion, laser-assisted proteolysis, and future prospects. It is expected that these novel proteolysis strategies accelerated by various electromagnetic waves will become powerful tools in proteome research and will find wide applications in high throughput protein digestion and identification. PMID:22379392

Accelerated digestion of nucleic acids by pepsin from the stomach of chicken.

PubMed

Liu, Y; Zhang, Y; Guo, H; Wu, W; Dong, P; Liang, X

2016-10-01

Nucleic acids have become an important nutritional supplement in poultry feed; however, the digestion of nucleic acids in poultry is unclear. The objective of this study was to investigate the digestion of nucleic acids by chicken pepsin in vitro. The extracted pepsinogen from the stomach of the chicken was purified to homogeneity. Upon activation at pH 2.0, chicken pepsinogen was converted to its active form. Nucleic acids, including λ-DNA, salmon sperm DNA and single-strand DNA (ssDNA), can be used as substrates and digested into short-chain oligonucleotides by pepsin. Interestingly, the digestion of the nucleic acids was inhibited when pepsin was treated by alkaline solution (pH 8.0) or pepstatin A. Also, the digestion of the nucleic acids was not affected by the addition of haemoglobin or bovine serum albumin. The results suggested that nucleic acids could be digested by chicken pepsin. Thus pepsin may have a role in digesting nucleic acids in vivo. Nucleic acids added to poultry fed may be digested, starting from the stomach.

Peptides derived from tryptic hydrolysate of Bacillus subtilis culture suppress fungal spoilage of table grapes.

PubMed

Zhang, Bo; Wang, Jingnan; Ning, Shuqing; Yuan, Quan; Chen, Xiangning; Zhang, Yanyan; Fan, Junfeng

2018-01-15

This study confirmed the anti-fungal effect of trypsin-treated Bacillus subtilis culture (BC) (tryptic hydrolysate, TH) on mold growth on Kyoho grapes. We examined the anti-fungal activity of TH by identifying TH peptides and performing a computational docking analysis. TH was more potent than untreated BC in suppressing fungal growth on grapes. Specifically, TH maintained grape freshness by inhibiting respiration and rachis browning, maintaining firmness, and preventing weight loss. Thirty-six inhibitory peptides against β-1,3-glucan synthase (GS) were screened from 126 TH peptides identified through proteomic analysis. Among them, 13 peptides bound tightly to GS active pockets with lower binding energies than that of GppNHp. The most potent peptides, LFEIDEELNEK and FATSDLNDLYR, were synthesized, and further experiments showed that these peptides had a highly suppressive effect on GS activity and Aspergillus niger and Penicillium chrysogenum growth. Our results confirm that tryptic treatment is effective for improving the anti-fungal activity of BC. Copyright © 2017 Elsevier Ltd. All rights reserved.

Inactivation of Staphylococcus aureus and Salmonella enteritidis in tryptic soy broth and caviar samples by high pressure processing.

PubMed

Fioretto, F; Cruz, C; Largeteau, A; Sarli, T A; Demazeau, G; El Moueffak, A

2005-08-01

We studied the action of high pressure processing on the inactivation of two foodborne pathogens, Staphylococcus aureus ATCC 6538 and Salmonella enteritidis ATCC 13076, suspended in a culture medium and inoculated into caviar samples. The baroresistance of the two pathogens in a tryptic soy broth suspension at a concentration of 10(8)-10(9) colony-forming units/ml was tested for continuous and cycled pressurization in the 150- to 550-MPa range and for 15-min treatments at room temperature. The increase of cycle number permitted the reduction of the pressure level able to totally inactivate both microorganisms in the tryptic soy broth suspension, whereas the effect of different procedure times on complete inactivation of the microorganisms inoculated into caviar was similar.

Effects of spray drying and size reduction of edible bird's nest on in-vitro digestibility

NASA Astrophysics Data System (ADS)

Muslim, Masitah; Babji, Abdul Salam; Mustapha, Wan Aida Wan

2015-09-01

The purpose of this study is to determine the effects of spray drying and size reduction of edible bird's nest (EBN) on in-vitro digestibility respectively. Sample prepared were EBN microparticulates; 710 µm (EBN710), 300 µm (EBN300) and 38 µm (EBN38), EBN spray died (EBNSD) and raw EBN (EBNraw) as control. Protein content and solubility were determined before the samples being subjected to in-vitro digestibility. Protein content of EBN710 (55.37±0.269%), EBN300 (56.57±0.163%) EBN38 (56.77±0.021%) and EBNraw (55.46±0.269%) was not significantly different (p>0.05) but EBNSD (60.33b+0.346%) was the highest (p<0.05). Solubility results showed that EBNSD had the highest solubility (94.38±1.24%) in water significantly (p<0.05) compared to EBNraw (16.01±0.231%), EBN710 (21.89+0.41%), EBN300 (22.52+0.072%) and EBN38 (27.51±0.321%). Digestibility of EBN300 (88.43±0.95%) was higher (p<0.05) compared to EBNSD (85.23±0.27%). However, treatment of microparticulates and spray drying were not significantly different with EBNraw (85.38±1.12%). Digestibility of EBN microparticulates and spray dried powder were all lower (p<0.05) than casein (98.36+0.95%). Lower EBN digestibility could be due to the nature of EBN protein as glycoprotein. Proteolytic (tryptic) digestion of native glycoprotein is often incomplete due to ste aric hindrance from the presence of bulky oligosaccharides.

Confetti: A Multiprotease Map of the HeLa Proteome for Comprehensive Proteomics*

PubMed Central

Guo, Xiaofeng; Trudgian, David C.; Lemoff, Andrew; Yadavalli, Sivaramakrishna; Mirzaei, Hamid

2014-01-01

Bottom-up proteomics largely relies on tryptic peptides for protein identification and quantification. Tryptic digestion often provides limited coverage of protein sequence because of issues such as peptide length, ionization efficiency, and post-translational modification colocalization. Unfortunately, a region of interest in a protein, for example, because of proximity to an active site or the presence of important post-translational modifications, may not be covered by tryptic peptides. Detection limits, quantification accuracy, and isoform differentiation can also be improved with greater sequence coverage. Selected reaction monitoring (SRM) would also greatly benefit from being able to identify additional targetable sequences. In an attempt to improve protein sequence coverage and to target regions of proteins that do not generate useful tryptic peptides, we deployed a multiprotease strategy on the HeLa proteome. First, we used seven commercially available enzymes in single, double, and triple enzyme combinations. A total of 48 digests were performed. 5223 proteins were detected by analyzing the unfractionated cell lysate digest directly; with 42% mean sequence coverage. Additional strong-anion exchange fractionation of the most complementary digests permitted identification of over 3000 more proteins, with improved mean sequence coverage. We then constructed a web application (https://proteomics.swmed.edu/confetti) that allows the community to examine a target protein or protein isoform in order to discover the enzyme or combination of enzymes that would yield peptides spanning a certain region of interest in the sequence. Finally, we examined the use of nontryptic digests for SRM. From our strong-anion exchange fractionation data, we were able to identify three or more proteotypic SRM candidates within a single digest for 6056 genes. Surprisingly, in 25% of these cases the digest producing the most observable proteotypic peptides was neither trypsin nor Lys

Doxycycline Indirectly Inhibits Proteolytic Activation of Tryptic Kallikrein-Related Peptidases and Activation of Cathelicidin

PubMed Central

Kanada, Kimberly N.; Nakatsuji, Teruaki; Gallo, Richard L.

2014-01-01

The increased abundance and activity of cathelicidin and kallikrein 5 (KLK5), a predominant trypsin-like serine protease (TLSP) in the stratum corneum, have been implicated in the pathogenesis of rosacea, a disorder treated by the use of low-dose doxycycline. Here we hypothesized that doxycycline can inhibit activation of tryptic KLKs through an indirect mechanism by inhibition of matrix metalloproteinases (MMPs) in keratinocytes. The capacity of doxycycline to directly inhibit enzyme activity was measured in surface collections of human facial skin and extracts of cultured keratinocytes by fluorescence polarization assay against fluorogenic substrates specific for MMPs or TLSPs. Doxycycline did inhibit MMP activity but did not directly inhibit serine protease activity against a fluorogenic substrate specific for TLSPs. However, when doxycycline or other MMP inhibitors were added to live keratinocytes during the production of tryptic KLKs, this treatment indirectly resulted in decreased TLSP activity. Furthermore, doxycycline under these conditions inhibited the generation of the cathelicidin peptide LL-37 from its precursor protein hCAP18, a process dependent on KLK activity. These results demonstrate that doxycycline can prevent cathelicidin activation, and suggest a previously unknown mechanism of action for doxycycline through inhibiting generation of active cathelicidin peptides. PMID:22336948

An EThcD-Based Method for Discrimination of Leucine and Isoleucine Residues in Tryptic Peptides

NASA Astrophysics Data System (ADS)

Zhokhov, Sergey S.; Kovalyov, Sergey V.; Samgina, Tatiana Yu.; Lebedev, Albert T.

2017-08-01

An EThcD-based approach for the reliable discrimination of isomeric leucine and isoleucine residues in peptide de novo sequencing procedure has been proposed. A multistage fragmentation of peptide ions was performed with Orbitrap Elite mass spectrometer in electrospray ionization mode. At the first stage, z-ions were produced by ETD or ETcaD fragmentation of doubly or triply charged peptide precursor ions. These primary ions were further fragmented by HCD with broad-band ion isolation, and the resulting w-ions showed different mass for leucine and isoleucine residues. The procedure did not require manual isolation of specific z-ions prior to HCD stage. Forty-three tryptic peptides (3 to 27 residues) obtained by trypsinolysis of human serum albumin (HSA) and gp188 protein were analyzed. To demonstrate a proper solution for radical site migration problem, three non-tryptic peptides were also analyzed. A total of 93 leucine and isoleucine residues were considered and 83 of them were correctly identified. The developed approach can be a reasonable substitution for additional Edman degradation procedure, which is still used in peptide sequencing for leucine and isoleucine discrimination.

Comparative Proteomic Analysis of Three Gelatinous Chinese Medicines and Their Authentications by Tryptic-digested Peptides Profiling using Matrix-assisted Laser Desorption/Ionization-time of Flight/Time of Flight Mass Spectrometry.

PubMed

Yang, Huan; Zheng, Jie; Wang, Hai-Yan; Li, Nan; Yang, Ya-Ya; Shen, Yu-Ping

2017-01-01

Gelatinous Chinese medicines (GCMs) including Asini Corii Colla, Testudinis Carapacis ET Plastri Colla, and Cervi Cornus Colla, were made from reptile shell or mammalian skin or deer horn, and consumed as a popular tonic, as well as hemopoietic and hemostatic agents. Misuse of them would not exert their functions, and fake or adulterate products have caused drug market disorder and affected food and drug safety. GCMs are rich in denatured proteins, but insufficient in available DNA fragments, hence commonly used cytochrome c oxidase I barcoding was not successful for their authentication. In this study, we performed comparative proteomic analysis of them and their animal origins to identify the composition of intrinsic proteins for the first time. A reliable and convenient approach was proposed for their authentication, by the incorporation of sodium dodecyl sulfate-polyacrylamide gel electrophoresis, two-dimensional electrophoresis, and matrix-assisted laser desorption/ionization-time of flight/time of flight mass spectrometry (MALDI-TOF/TOF-MS). A total of 26 proteins were identified from medicinal parts of original animals, and GCMs proteins presented in a dispersive manner in electrophoresis analyses due to complicated changes in the structure of original proteins caused by long-term decoction and the addition of ingredients during their manufacturing. In addition, by comparison of MALDI-TOF/TOF-MS profiling, 19 signature peptide fragments originated from the protein of GCM products were selected according to criteria. These could assist in the discrimination and identification of adulterates of GCMs and other ACMs for their form of raw medicinal material, the pulverized, and even the complex. Comparative proteomic analysis of three gelatinous Chinese medicines was conducted, and their authentications were based on tryptic-digested peptides profiling using matrix-assisted laser desorption/ionization-time of flight/time of flight mass spectrometry. Abbreviations

Limited tryptic proteolysis of the benzodiazepine binding proteins in different species reveals structural homologies.

PubMed

Friedl, W; Lentes, K U; Schmitz, E; Propping, P; Hebebrand, J

1988-12-01

Peptide mapping can be used to elucidate further the structural similarities of the benzodiazepine binding proteins in different vertebrate species. Crude synaptic membrane preparations were photoaffinity-labeled with [3H]flunitrazepam and subsequently degraded with various concentrations of trypsin. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by fluorography allowed a comparison of the molecular weights of photolabeled peptides in different species. Tryptic degradation led to a common peptide of 40K in all species investigated, a finding indicating that the benzodiazepine binding proteins are structurally homologous in higher bony fishes and tetrapods.

Enhanced anaerobic digestion of waste activated sludge digestion by the addition of zero valent iron.

PubMed

Feng, Yinghong; Zhang, Yaobin; Quan, Xie; Chen, Suo

2014-04-01

Anaerobic digestion is promising technology to recover energy from waste activated sludge. However, the sludge digestion is limited by its low efficiency of hydrolysis-acidification. Zero valent iron (ZVI) as a reducing material is expected to enhance anaerobic process including the hydrolysis-acidification process. Considering that, ZVI was added into an anaerobic sludge digestion system to accelerate the sludge digestion in this study. The results indicated that ZVI effectively enhanced the decomposition of protein and cellulose, the two main components of the sludge. Compared to the control test without ZVI, the degradation of protein increased 21.9% and the volatile fatty acids production increased 37.3% with adding ZVI. More acetate and less propionate are found during the hydrolysis-acidification with ZVI. The activities of several key enzymes in the hydrolysis and acidification increased 0.6-1 time. ZVI made the methane production raise 43.5% and sludge reduction ratio increase 12.2 percent points. Fluorescence in situ hybridization analysis showed that the abundances of hydrogen-consuming microorganisms including homoacetogens and hydrogenotrophic methanogens with ZVI were higher than the control, which reduced the H2 accumulation to create a beneficial condition for the sludge digestion in thermodynamics. Copyright © 2013 Elsevier Ltd. All rights reserved.

Digestive stimulant action of spices: a myth or reality?

PubMed

Platel, Kalpana; Srinivasan, K

2004-05-01

Spices have long been recognized for their digestive stimulant action. Several spices are also employed in medicinal preparations against digestive disorders in traditional and Indian systems of medicine. Earlier reports on the digestive stimulant action of spices are largely empirical; only in recent years, this beneficial attribute of spices has been authenticated in exhaustive animal studies. Animal studies have shown that many spices induce higher secretion of bile acids which play a vital role in fat digestion and absorption. When consumed through the diet also spices produce significant stimulation of the activities of pancreatic lipase, amylase and proteases. A few of them also have been shown to have beneficial effect on the terminal digestive enzymes of small intestinal mucosa. Concomitant with such a stimulation of either bile secretion or activity of digestive enzymes by these spices, leading to an accelerated digestion, a reduction in the food transit time in the gastrointestinal tract has also been shown. Thus, the digestive stimulant action of spices seems to be mediated through two possible modes: (i) by stimulating the liver to secrete bile rich in bile acids, components that are vital for fat digestion and absorption, and (ii) by a stimulation of enzyme activities that are responsible for digestion. This review highlights the available information on the influence of spices on the digestive secretions and enzymes.

The tryptic cleavage product of the mature form of the bovine desmoglein 1 ectodomain is one of the antigen moieties immunoprecipitated by all sera from symptomatic patients affected by a new variant of endemic pemphigus.

PubMed

Abréu-Vélez, Ana María; Javier Patiño, Pablo; Montoya, Fernando; Bollag, Wendy B

2003-01-01

Multiple antigens are recognized by sera from patients with pemphigus foliaceus (PF). Several have been identified including keratin 59, desmocollins, envoplakin, periplakin, and desmogleins 1 and 3 (Dsg1 and Dsg3). In addition, an 80 kDa antigen was identified as the N-terminal fragment of Dsg1 using as antigen source an insoluble epidermal cell envelope preparation. However, still unsolved was the identity of the most important antigenic moiety, a 45 kDa tryptic fragment which is recognized by all sera from patients with fogo selvagem, pemphigus foliaceus, by half of pemphigus vulgaris sera and by a new variant of endemic pemphigus in E1 Bagre, Colombia that resembles Senear-Usher syndrome. Here, we report the identification of the 45 kDa conformational epitope of a soluble tryptic cleavage product from viable bovine epidermis. To elucidate the nature of this peptide, viable bovine epidermis was trypsin-digested, and glycosylated peptides were partially purified on a concanavalin A (Con-A) affinity column. This column fraction was then used as an antigen source for further immunoaffinity purification. A PF patient's serum covalently coupled to a Staphylococcus aureus protein A column was incubated with the Con-A eluted products and the immuno-isolated antigen was separated by SDS-PAGE, transferred to a membrane, and visualized with Coomassie blue, silver and amido black stains. The 45 kD band was subjected to amino acid sequence analysis revealing the sequence, EXIKFAAAXREGED, which matched the mature form of the extracellular domain of bovine Dsg1. This study confirms the biological importance of the ectodomain of Dsg1 as well as the relevance of conformational epitopes in various types of pemphigus.

Conductive iron oxides accelerate thermophilic methanogenesis from acetate and propionate.

PubMed

Yamada, Chihaya; Kato, Souichiro; Ueno, Yoshiyuki; Ishii, Masaharu; Igarashi, Yasuo

2015-06-01

Anaerobic digester is one of the attractive technologies for treatment of organic wastes and wastewater, while continuous development and improvements on their stable operation with efficient organic removal are required. Particles of conductive iron oxides (e.g., magnetite) are known to facilitate microbial interspecies electron transfer (termed as electric syntrophy). Electric syntrophy has been reported to enhance methanogenic degradation of organic acids by mesophilic communities in soil and anaerobic digester. Here we investigated the effects of supplementation of conductive iron oxides (magnetite) on thermophilic methanogenic microbial communities derived from a thermophilic anaerobic digester. Supplementation of magnetite accelerated methanogenesis from acetate and propionate under thermophilic conditions, while supplementation of ferrihydrite also accelerated methanogenesis from propionate. Microbial community analysis revealed that supplementation of magnetite drastically changed bacterial populations in the methanogenic acetate-degrading cultures, in which Tepidoanaerobacter sp. and Coprothermobacter sp. dominated. These results suggest that supplementation of magnetite induce electric syntrophy between organic acid-oxidizing bacteria and methanogenic archaea and accelerate methanogenesis even under thermophilic conditions. Findings from this study would provide a possibility for the achievement of stably operating thermophilic anaerobic digestion systems with high efficiency for removal of organics and generation of CH4. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Characterization of the interaction between subunits of the botulinum toxin complex produced by serotype D through tryptic susceptibility of the isolated components and complex forms.

PubMed

Suzuki, Tomonori; Watanabe, Toshihiro; Mutoh, Shingo; Hasegawa, Kimiko; Kouguchi, Hirokazu; Sagane, Yoshimasa; Fujinaga, Yukako; Oguma, Keiji; Ohyama, Tohru

2005-05-01

The 650 kDa large toxin complex (L-TC) produced by Clostridium botulinum serotype D strain 4947 (D-4947) has a subunit structure composed of unnicked components, i.e. neurotoxin (NT), non-toxic non-haemagglutinin (NTNHA) and three haemagglutinin subcomponents (HA-70, HA-33 and HA-17). In this study, subunit interactions were investigated through the susceptibilities of the toxin components to limited trypsin proteolysis. Additionally, complex forms were reconstituted in vitro by various combinations of individual components. Trypsin treatment of intact D-4947 L-TC led to the formation of mature L-TC with nicks at specific sites of each component, which is usually observed in other strains of serotype D. NT, NTNHA and HA-17 were cleaved at their specific sites in either the single or complex forms, but HA-33 showed no sign of proteolysis. Unlike the other components, HA-70 was digested into random fragments as a single form, but it was cleaved into two fragments in the complex form. Based on the relative position of exposed or hidden regions of the individual components in the complex derived from their tryptic susceptibilities, an assembly model is proposed for the arrangement of individual subunits in the botulinum L-TC.

Sophisticated digestive systems in early arthropods.

PubMed

Vannier, Jean; Liu, Jianni; Lerosey-Aubril, Rudy; Vinther, Jakob; Daley, Allison C

2014-05-02

Understanding the way in which animals diversified and radiated during their early evolutionary history remains one of the most captivating of scientific challenges. Integral to this is the 'Cambrian explosion', which records the rapid emergence of most animal phyla, and for which the triggering and accelerating factors, whether environmental or biological, are still unclear. Here we describe exceptionally well-preserved complex digestive organs in early arthropods from the early Cambrian of China and Greenland with functional similarities to certain modern crustaceans and trace these structures through the early evolutionary lineage of fossil arthropods. These digestive structures are assumed to have allowed for more efficient digestion and metabolism, promoting carnivory and macrophagy in early arthropods via predation or scavenging. This key innovation may have been of critical importance in the radiation and ecological success of Arthropoda, which has been the most diverse and abundant invertebrate phylum since the Cambrian.

Detection and Quantitation of Afucosylated N-Linked Oligosaccharides in Recombinant Monoclonal Antibodies Using Enzymatic Digestion and LC-MS

NASA Astrophysics Data System (ADS)

Du, Yi; May, Kimberly; Xu, Wei; Liu, Hongcheng

2012-07-01

The presence of N-linked oligosaccharides in the CH2 domain has a significant impact on the structure, stability, and biological functions of recombinant monoclonal antibodies. The impact is also highly dependent on the specific oligosaccharide structures. The absence of core-fucose has been demonstrated to result in increased binding affinity to Fcγ receptors and, thus, enhanced antibody-dependent cellular cytotoxicity (ADCC). Therefore, a method that can specifically determine the level of oligosaccharides without the core-fucose (afucosylation) is highly desired. In the current study, recombinant monoclonal antibodies and tryptic peptides from the antibodies were digested using endoglycosidases F2 and H, which cleaves the glycosidic bond between the two primary GlcNAc residues. As a result, various oligosaccharides of either complex type or high mannose type that are commonly observed for recombinant monoclonal antibodies are converted to either GlcNAc residue only or GlcNAc with the core-fucose. The level of GlcNAc represents the sum of all afucosylated oligosaccharides, whereas the level of GlcNAc with the core-fucose represents the sum of all fucosylated oligosaccharides. LC-MS analysis of the enzymatically digested antibodies after reduction provided a quick estimate of the levels of afucosylation. An accurate determination of the level of afucosylation was obtained by LC-MS analysis of glycopeptides after trypsin digestion.

Comprehensive two-dimensional liquid chromatography of therapeutic monoclonal antibody digests.

PubMed

Vanhoenacker, Gerd; Vandenheede, Isabel; David, Frank; Sandra, Pat; Sandra, Koen

2015-01-01

Comprehensive two-dimensional liquid chromatography (LC×LC) is here proposed as a novel tool for peptide mapping of therapeutic monoclonal antibodies in both R&D and routine (QA/QC) environments. This is illustrated by the analysis of the tryptic digest of trastuzumab (Herceptin) applying a commercially available two-dimensional 2D-LC system. Three different LC×LC combinations, i.e., strong cation-exchange × reversed-phase (SCX×RP), reversed-phase × reversed-phase (RP×RP), and hydrophilic interaction × reversed-phase (HILIC×RP), are reported. Detection was carried out using both UV detection (DAD) and mass spectrometry (MS). Several challenges related to the application of LC×LC in peptide mapping and the hyphenation to MS are addressed. The applicability of LC×LC in the assessment of identity, purity, and comparability is demonstrated by the analysis of different Herceptin innovator production batches, a Herceptin biosimilar in development and of stressed samples. The described methodology was shown to be precise in terms of peak volume and (2)D retention time opening interesting perspectives for use in QA/QC testing.

Temperature-dependent instability of the cTnI subunit in NIST SRM2921 characterized by tryptic peptide mapping.

PubMed

van der Burgt, Yuri E M; Cobbaert, Christa M; Dalebout, Hans; Smit, Nico; Deelder, André M

2012-08-01

In this study temperature-dependent instability of the cTnI subunit of the three-protein complex NIST SRM2921 was demonstrated using a mass spectrometric tryptic peptide mapping approach. The results were compared to the cTnI subunit obtained as a protein standard from Calbiochem with identical amino acid sequence. Both the three-protein complex from NIST as well as the cTnI subunit were incubated at elevated temperatures and then evaluated with respect to the primary sequence. The corresponding peptide maps were analyzed using LC-MS/MS. From a Mascot database search in combination with "semiTrypsin" tolerance it was found that two peptide backbone cleavages had occurred in subunit cTnI in NIST SRM2921 material upon incubation at 37°C, namely between amino acids at 148/149 and 194/195. The Calbiochem standard did not show increased levels of "unexpected" peptides in tryptic peptide maps. One of the two peptide backbone cleavages could also be monitored using a "single-step" MALDI-MS approach, i.e. without the need for peptide separation. The amount of degradation appeared rather constant in replicate temperature-instability experiments. However, for accurate quantification internal labelled standards are needed. Copyright © 2012 Elsevier B.V. All rights reserved.

Amino acid sequences of peptides from a chymotryptic digest of a urea-soluble protein fraction (U.S.3) from oxidized wool

PubMed Central

Corfield, M. C.; Fletcher, J. C.

1969-01-01

1. A chymotryptic digest of the protein fraction U.S.3. from oxidized wool was separated into 51 peptide fractions by chromatography on a column of cation-exchange resin. 2. The less acidic fractions were separated into their component peptides by a combination of cation-exchange-resin chromatography, paper chromatography and paper electrophoresis. 3. The amino acid sequences of 34 of these peptides were elucidated, and those of 14 others partially determined. 4. Overlaps between the tryptic and chymotryptic peptides from fraction U.S.3 have enabled ten extended amino acid sequences to be deduced, the longest containing 20 amino acid residues. 5. The relevance of the results to the structures of the helical and non-helical regions of wool is discussed. PMID:5395876

Apocalmodulin and Ca2+ calmodulin bind to the same region on the skeletal muscle Ca2+ release channel

NASA Technical Reports Server (NTRS)

Moore, C. P.; Rodney, G.; Zhang, J. Z.; Santacruz-Toloza, L.; Strasburg, G.; Hamilton, S. L.

1999-01-01

The skeletal muscle Ca2+ release channel (RYR1) is regulated by calmodulin in both its Ca2+-free (apocalmodulin) and Ca2+-bound (Ca2+ calmodulin) states. Apocalmodulin is an activator of the channel, and Ca2+ calmodulin is an inhibitor of the channel. Both apocalmodulin and Ca2+ calmodulin binding sites on RYR1 are destroyed by a mild tryptic digestion of the sarcoplasmic reticulum membranes, but calmodulin (either form), bound to RYR1 prior to tryptic digestion, protects both the apocalmodulin and Ca2+ calmodulin sites from tryptic destruction. The protected sites are after arginines 3630 and 3637 on RYR1. These studies suggest that both Ca2+ calmodulin and apocalmodulin bind to the same or overlapping regions on RYR1 and block access of trypsin to sites at amino acids 3630 and 3637. This sequence is part of a predicted Ca2+ CaM binding site of amino acids 3614-3642 [Takeshima, H., et al. (1989) Nature 339, 439-445].

Integrated microreactor for enzymatic reaction automation: An easy step toward the quality control of monoclonal antibodies.

PubMed

Ladner, Yoann; Mas, Silvia; Coussot, Gaelle; Bartley, Killian; Montels, Jérôme; Morel, Jacques; Perrin, Catherine

2017-12-15

The main purpose of the present work is to provide a fully integrated miniaturized electrophoretic methodology in order to facilitate the quality control of monoclonal antibodies (mAbs). This methodology called D-PES, which stands for Diffusion-mediated Proteolysis combined with an Electrophoretic Separation, permits to perform subsequently mAb tryptic digestion and electrophoresis separation of proteolysis products in an automated manner. Tryptic digestion conditions were optimized regarding the influence of enzyme concentration and incubation time in order to achieve similar enzymatic digestion efficiency to that obtained with the classical methodology (off-line). Then, the optimization of electrophoretic separation conditions concerning the nature of background electrolyte (BGE), ionic strength and pH was realized. Successful and repeatable electrophoretic profiles of three mAbs digests (Trastuzumab, Infliximab and Tocilizumab), comparable to the off-line digestion profiles, were obtained demonstrating the feasibility and robustness of the proposed methodology. In summary, the use of the proposed and optimized in-line approach opens a new, fast and easy way for the quality control of mAbs. Copyright © 2017 Elsevier B.V. All rights reserved.

Rapid micro-scale proteolysis of proteins for MALDI-MS peptide mapping using immobilized trypsin

NASA Astrophysics Data System (ADS)

Gobom, Johan; Nordhoff, Eckhard; Ekman, Rolf; Roepstorff, Peter

1997-12-01

In this study we present a rapid method for tryptic digestion of proteins using micro-columns with enzyme immobilized on perfusion chromatography media. The performance of the method is exemplified with acyl-CoA-binding protein and reduced carbamidomethylated bovine serum albumin. The method proved to be significantly faster and yielded a better sequence coverage and an improved signal-to-noise ratio for the MALDI-MS peptide maps, compared to in-solution- and on-target digestion. Only a single sample transfer step is required, and therefore sample loss due to adsorption to surfaces is reduced, which is a critical issue when handling low picomole to femtomole amounts of proteins. An example is shown with on-column proteolytic digestion and subsequent elution of the digest into a reversed-phase micro-column. This is useful if the sample contains large amounts of salt or is too diluted for MALDI-MS analysis. Furthermore, by step-wise elution from the reversedphase column, a complex digest can be fractionated, which reduces signal suppression and facilitates data interpretation in the subsequent MS-analysis. The method also proved useful for consecutive digestions with enzymes of different cleavage specificity. This is exemplified with on-column tryptic digestion, followed by reversed-phase step-wise elution, and subsequent on-target V8 protease digestion.

Enhancement of anaerobic sludge digestion by high-pressure homogenization.

PubMed

Zhang, Sheng; Zhang, Panyue; Zhang, Guangming; Fan, Jie; Zhang, Yuxuan

2012-08-01

To improve anaerobic sludge digestion efficiency, the effects of high-pressure homogenization (HPH) conditions on the anaerobic sludge digestion were investigated. The VS and TCOD were significantly removed with the anaerobic digestion, and the VS removal and TCOD removal increased with increasing the homogenization pressure and homogenization cycle number; correspondingly, the accumulative biogas production also increased with increasing the homogenization pressure and homogenization cycle number. The optimal homogenization pressure was 50 MPa for one homogenization cycle and 40 MPa for two homogenization cycles. The SCOD of the sludge supernatant significantly increased with increasing the homogenization pressure and homogenization cycle number due to the sludge disintegration. The relationship between the biogas production and the sludge disintegration showed that the accumulative biogas and methane production were mainly enhanced by the sludge disintegration, which accelerated the anaerobic digestion process and improved the methane content in the biogas. Copyright © 2012 Elsevier Ltd. All rights reserved.

Digestion of Protein in Premature and Term Infants

PubMed Central

Dallas, David C; Underwood, Mark A; Zivkovic, Angela M.; German, J. Bruce

2014-01-01

Premature birth rates and premature infant morbidity remain discouragingly high. Improving nourishment for these infants is the key for accelerating their development and decreasing disease risk. Dietary protein is essential for growth and development of infants. Studies on protein nourishment for premature infants have focused on protein requirements for catch-up growth, nitrogen balance, and digestive protease concentrations and activities. However, little is known about the processes and products of protein digestion in the premature infant. This review briefly summarizes the protein requirements of term and preterm infants, and the protein content of milk from women delivering preterm and at term. An in-depth review is presented of the current knowledge of term and preterm infant dietary protein digestion, including human milk protease and anti-protease concentrations; neonatal intestinal pH, and enzyme activities and concentrations; and protein fermentation by intestinal bacteria. The advantages and disadvantages of incomplete protein digestion as well as factors that increase resistance to proteolysis of particular proteins are discussed. In order to better understand protein digestion in preterm and term infants, future studies should examine protein and peptide fragment products of digestion in saliva, gastric, intestinal and fecal samples, as well as the effects of the gut micro biome on protein degradation. The confluence of new mass spectrometry technology and new bioinformatics programs will now allow thorough identification of the array of peptides produced in the infant as they are digested. PMID:24744976

Nature of autofluorescence in human serum albumin under its native, unfolding and digested forms

NASA Astrophysics Data System (ADS)

Manjunath, S.; Rao, Bola Sadashiva Satish; Satyamoorthy, Kapaettu; Mahato, Krishna Kishore

2014-02-01

Autofluorescence characteristics of human serum albumin (HSA) are highly sensitive to its local environment. Identification and characterization of the proteins in normal and disease conditions may have great clinical implications. Aim of the present study was to understand how autofluorescence properties of HSA varies with denaturation under urea (3.0M, 6.0M, 9.0M) and guanidine hydrochloride (GnHCl) (2.0M, 4.0M, 6.0M) as well as digestion with trypsin. Towards this, we have recorded the corresponding autofluorescence spectra of HSA at 281nm laser excitation and compared the outcomes. Although, HSA contains 1 tryptophan and 17 tyrosine residues, it has shown intense autofluorescence due to tryptophan as compared to the tyrosine in native form, which may be due to the fluorescence resonance energy transfer (FRET) from tyrosine to tryptophan. As the unfolding progresses in denatured and digested forms of the protein, a clear increase in tyrosine fluorescence as compared to tryptophan was observed, which may be due to the increase of tryptophan - tyrosine separation disturbing the FRET between them resulting in differences in the overall autofluorescence properties. The decrease in tryptophan fluorescence of around 17% in urea denatured, 32% in GnHCl denatured and 96% in tryptic digested HSA was observed as compared to its native form. The obtained results show a clear decrease in FRET between tyrosine and tryptophan residues with the progression of unfolding and urea seems to be less efficient than GnHCl in unfolding of HSA. These results demonstrate the potential of autofluorescence in characterizing proteins in general and HSA in particular.

Managing Organizational Change in the Community College. ERIC Digest.

ERIC Educational Resources Information Center

Kozeracki, Carol

This digest discusses two recurrent themes presented in the New Directions for Community Colleges volume titled "Organizational Change in the Community College: Ripple or Sea Change?" First, change in the external environment is accelerating, and colleges must respond to these changes to thrive. External environmental influences include…

Mass spectrometry compatible surfactant for optimized in-gel protein digestion.

PubMed

Saveliev, Sergei V; Woodroofe, Carolyn C; Sabat, Grzegorz; Adams, Christopher M; Klaubert, Dieter; Wood, Keith; Urh, Marjeta

2013-01-15

Identification of proteins resolved by SDS-PAGE depends on robust in-gel protein digestion and efficient peptide extraction, requirements that are often difficult to achieve. A lengthy and laborious procedure is an additional challenge of protein identification in gel. We show here that with the use of the mass spectrometry compatible surfactant sodium 3-((1-(furan-2-yl)undecyloxy)carbonylamino)propane-1-sulfonate, the challenges of in-gel protein digestion are effectively addressed. Peptide quantitation based on stable isotope labeling showed that the surfactant induced 1.5-2 fold increase in peptide recovery. Consequently, protein sequence coverage was increased by 20-30%, on average, and the number of identified proteins saw a substantial boost. The surfactant also accelerated the digestion process. Maximal in-gel digestion was achieved in as little as one hour, depending on incubation temperature, and peptides were readily recovered from gel eliminating the need for postdigestion extraction. This study shows that the surfactant provides an efficient means of improving protein identification in gel and streamlining the in-gel digestion procedure requiring no extra handling steps or special equipment.

Investigation and reduction of sub-microgram peptide loss using molecular weight cut-off fractionation prior to mass spectrometric analysis

PubMed Central

Cunningham, Robert; Wang, Jingxin; Wellner, Daniel; Li, Lingjun

2013-01-01

This work investigates the suitability of molecular weight cut-off membrane-based centrifugal filter devices (MWCO) for sub-microgram peptide enrichment passing through the membrane by introduction of methanol and a salt modifier. Using a neuropeptide standard, bradykinin, a reduction in sample loss of over two orders of magnitude is demonstrated with and without undigested protein present. Additionally, a bovine serum albumin (BSA) tryptic digestion was investigated and 27 tryptic peptides were identified using MALDI mass spectrometry whereas only two BSA tryptic peptides were identified after MWCO separation using H2O. The protocol presented here enhances recovery from MWCO separation for sub-μg peptide samples. PMID:23019164

Functional Fe3O4@ZnO magnetic nanoparticle-assisted enrichment and enzymatic digestion of phosphoproteins from saliva.

PubMed

Chen, Wei-Yu; Chen, Yu-Chie

2010-11-01

Saliva contains various proteins, particularly abundant are phosphoproteins, that may be related to disease occurrences and that play significant roles in a biological system. Thus, medical diagnostics will benefit tremendously if disease-related protein biomarkers are discovered from saliva. In this paper, we propose and demonstrate an approach using functional zinc oxide coated iron oxide magnetic nanoparticles (Fe(3)O(4)@ZnO MNPs) as affinity probes to selectively enrich phosphoproteins from complex saliva samples and as microwave absorbers to assist the enrichment and subsequent tryptic digestion of trapped proteins under microwave heating. The target species trapped by MNPs were characterized by matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) combined with protein database search. Entire analysis time was shortened to less than 20 min. The detection limit of this approach for a monophosphopeptide was as low as 250 pM (10 μL).

Engineering Digestion: Multiscale Processes of Food Digestion.

PubMed

Bornhorst, Gail M; Gouseti, Ourania; Wickham, Martin S J; Bakalis, Serafim

2016-03-01

Food digestion is a complex, multiscale process that has recently become of interest to the food industry due to the developing links between food and health or disease. Food digestion can be studied by using either in vitro or in vivo models, each having certain advantages or disadvantages. The recent interest in food digestion has resulted in a large number of studies in this area, yet few have provided an in-depth, quantitative description of digestion processes. To provide a framework to develop these quantitative comparisons, a summary is given here between digestion processes and parallel unit operations in the food and chemical industry. Characterization parameters and phenomena are suggested for each step of digestion. In addition to the quantitative characterization of digestion processes, the multiscale aspect of digestion must also be considered. In both food systems and the gastrointestinal tract, multiple length scales are involved in food breakdown, mixing, absorption. These different length scales influence digestion processes independently as well as through interrelated mechanisms. To facilitate optimized development of functional food products, a multiscale, engineering approach may be taken to describe food digestion processes. A framework for this approach is described in this review, as well as examples that demonstrate the importance of process characterization as well as the multiple, interrelated length scales in the digestion process. © 2016 Institute of Food Technologists®

[Anaerobic digestion of lignocellulosic biomass with animal digestion mechanisms].

PubMed

Wu, Hao; Zhang, Pan-Yue; Guo, Jian-Bin; Wu, Yong-Jie

2013-02-01

Lignocellulosic material is the most abundant renewable resource in the earth. Herbivores and wood-eating insects are highly effective in the digestion of plant cellulose, while anaerobic digestion process simulating animal alimentary tract still remains inefficient. The digestion mechanisms of herbivores and wood-eating insects and the development of anaerobic digestion processes of lignocellulose were reviewed for better understanding of animal digestion mechanisms and their application in design and operation of the anaerobic digestion reactor. Highly effective digestion of lignocellulosic materials in animal digestive system results from the synergistic effect of various digestive enzymes and a series of physical and biochemical reactions. Microbial fermentation system is strongly supported by powerful pretreatment, such as rumination of ruminants, cellulase catalysis and alkali treatment in digestive tract of wood-eating insects. Oxygen concentration gradient along the digestive tract may stimulate the hydrolytic activity of some microorganisms. In addition, the excellent arrangement of solid retention time, digesta flow and end product discharge enhance the animal digestion of wood cellulose. Although anaerobic digestion processes inoculated with rumen microorganisms based rumen digestion mechanisms were developed to treat lignocellulose, the fermentation was more greatly limited by the environmental conditions in the anaerobic digestion reactors than that in rumen or hindgut. Therefore, the anaerobic digestion processes simulating animal digestion mechanisms can effectively enhance the degradation of wood cellulose and other organic solid wastes.

Accelerator infrastructure in Europe: EuCARD 2011

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2011-10-01

The paper presents a digest of the research results in the domain of accelerator science and technology in Europe, shown during the annual meeting of the EuCARD - European Coordination of Accelerator Research and Development. The conference concerns building of the research infrastructure, including in this advanced photonic and electronic systems for servicing large high energy physics experiments. There are debated a few basic groups of such systems like: measurement - control networks of large geometrical extent, multichannel systems for large amounts of metrological data acquisition, precision photonic networks of reference time, frequency and phase distribution.

Strengthen effects of dominant strains on aerobic digestion and stabilization of the residual sludge.

PubMed

Liu, Yongjun; Gao, Min; Zhang, Aining; Liu, Zhe

2017-07-01

In order to strengthen the aerobic digestion of residual sludge, shorten the time of sludge stabilization and further reduce operating costs, 3 dominant strains identified as Pseudomonas sp. L3, Acinetobacter sp. L16 and Bacillus sp. L19 were isolated from long-term aerobic digestion sludge. Results showed that the sludge stabilization time were reduced by 3-4days compared with the control when the dominant strains were added to the process of sludge aerobic digestion. The addition of dominant strains accelerated the accumulation of TOC, nitrate nitrogen and ammonia nitrogen in the digestive solution at different levels, and it was beneficial to the dissolution of phosphorus. Controlling DO 3-5mg/L, pH 6.5, the strains of Pseudomonas sp. L3 and Bacillus sp. L19 were combined dosing with the dosage of 2% in the process of sludge aerobic digestion, compared with the control, digestion rates of TOC and MLSS were increased about 19% and 16%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

Accelerators for society: succession of European infrastructural projects: CARE, EuCARD, TIARA, EuCARD2

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2013-10-01

Accelerator science and technology is one of a key enablers of the developments in the particle physic, photon physics and also applications in medicine and industry. The paper presents a digest of the research results in the domain of accelerator science and technology in Europe, shown during the realization of CARE (Coordinated Accelerator R&D), EuCARD (European Coordination of Accelerator R&D) and during the national annual review meeting of the TIARA - Test Infrastructure of European Research Area in Accelerator R&D. The European projects on accelerator technology started in 2003 with CARE. TIARA is an European Collaboration of Accelerator Technology, which by running research projects, technical, networks and infrastructural has a duty to integrate the research and technical communities and infrastructures in the global scale of Europe. The Collaboration gathers all research centers with large accelerator infrastructures. Other ones, like universities, are affiliated as associate members. TIARA-PP (preparatory phase) is an European infrastructural project run by this Consortium and realized inside EU-FP7. The paper presents a general overview of CARE, EuCARD and especially TIARA activities, with an introduction containing a portrait of contemporary accelerator technology and a digest of its applications in modern society. CARE, EuCARD and TIARA activities integrated the European accelerator community in a very effective way. These projects are expected very much to be continued.

EuCARD2: enhanced accelerator research and development in Europe

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2013-10-01

Accelerator science and technology is one of a key enablers of the developments in the particle physic, photon physics and also applications in medicine and industry. EuCARD2 is an European research project which will be realized during 2013-2017 inside the EC FP7 framework. The project concerns the development and coordination of European Accelerator Research and Development. The project is particularly important, to a number of domestic laboratories, due to some plans to build large accelerator infrastructure in Poland. Large accelerator infrastructure of fundamental and applied research character stimulates around it the development and industrial applications as well as biomedical of advanced accelerators, material research and engineering, cryo-technology, mechatronics, robotics, and in particular electronics - like networked measurement and control systems, sensors, computer systems, automation and control systems. The paper presents a digest of the European project EuCARD2 which is Enhanced European Coordination for Accelerator Research and Development. The paper presents a digest of the research results and assumptions in the domain of accelerator science and technology in Europe, shown during the final fourth annual meeting of the EuCARD - European Coordination of Accelerator R&D, and the kick-off meeting of the EuCARD2. There are debated a few basic groups of accelerator systems components like: measurement - control networks of large geometrical extent, multichannel systems for large amounts of metrological data acquisition, precision photonic networks of reference time, frequency and phase distribution, high field magnets, superconducting cavities, novel beam collimators, etc. The paper bases on the following materials: Internet and Intranet documents combined with EuCARD2, Description of Work FP7 EuCARD-2 DoW-312453, 2013-02-13, and discussions and preparatory materials worked on by Eucard-2 initiators.

Bioaffinity magnetic reactor for peptide digestion followed by analysis using bottom-up shotgun proteomics strategy.

PubMed

Korecká, Lucie; Jankovicová, Barbora; Krenková, Jana; Hernychová, Lenka; Slováková, Marcela; Le-Nell, Anne; Chmelik, Josef; Foret, Frantisek; Viovy, Jean-Louis; Bilková, Zusana

2008-02-01

We report an efficient and streamlined way to improve the analysis and identification of peptides and proteins in complex mixtures of soluble proteins, cell lysates, etc. By using the shotgun proteomics methodology combined with bioaffinity purification we can remove or minimize the interference contamination of a complex tryptic digest and so avoid the time-consuming separation steps before the final MS analysis. We have proved that by means of enzymatic fragmentation (endoproteinases with Arg-C or/and Lys-C specificity) connected with the isolation of specific peptides we can obtain a simplified peptide mixture for easier identification of the entire protein. A new bioaffinity sorbent was developed for this purpose. Anhydrotrypsin (AHT), an inactive form of trypsin with an affinity for peptides with arginine (Arg) or lysine (Lys) at the C-terminus, was immobilized onto micro/nanoparticles with superparamagnetic properties (silica magnetite particles (SiMAG)-Carboxyl, Chemicell, Germany). This AHT carrier with a determined binding capacity (26.8 nmol/mg of carrier) was tested with a model peptide, human neurotensin, and the resulting MS spectra confirmed the validity of this approach.

MALDI-based identification of stable hazelnut protein derived tryptic marker peptides.

PubMed

Cucu, T; De Meulenaer, B; Devreese, B

2012-01-01

Food allergy is an important health problem especially in industrialised countries. Tree nuts, among which are hazelnuts (Corylus avellana), are typically causing serious and life-threatening symptoms in sensitive subjects. Hazelnut is used as a food ingredient in pastry, confectionary products, ice cream and meat products, therefore undeclared hazelnut can be often present as a cross-contaminant representing a threat for allergic consumers. Mass spectrometric techniques are used for the detection of food allergens in processed foods, but limited information regarding stable tryptic peptide markers for hazelnut is available. The aim of this study was to detect stable peptide markers from modified hazelnut protein through the Maillard reaction and oxidation in a buffered solution. Peptides ³⁹⁵Gly-Arg⁴⁰³ from Cor a 11 and ²⁰⁹Gln-Arg²¹⁷, ³⁵¹Ile-Arg³⁶³, ⁴⁶⁴Ala-Arg⁴⁷⁸ and ⁴⁰¹Val-Arg⁴¹⁷ from Cor a 9 hazelnut allergens proved to be the most stable and could be detected and confirmed with high scores in most of the modified samples. The identified peptides can be further used as analytical targets for the development of more robust quantitative methods for hazelnut detection in processed foods.

Attomole-level protein fingerprinting based on intrinsic peptide fluorescence.

PubMed

Okerberg, E; Shear, J B

2001-04-01

Protein identification has relied heavily on proteolytic analysis, but current techniques are often slow and generally consume large quantities of valuable protein sample. We report the development of a rapid, ultralow volume protein analysis strategy based on tryptic digestion within the tip of a 1.5-microm capillary channel followed by separation of the proteolytic fragments using capillary electrophoresis (CE). Two-photon excitation is used to probe the intrinsic fluorescence of peptide fragments through "deep-UV" excitation of aromatic amino acid residues at the outlet of the CE channel. Detection limits using this technique are 0.7, 2.4, and 23 amol for the aromatic amino acids tryptophan, tyrosine, and phenylalanine, respectively. In these studies, we demonstrate the capacity to differentiate bovine and yeast cytochrome c variants using less than 15 amol of protein through tryptic fingerprinting. Moreover, the detection of a single amino acid substitution between bovine and canine cytochrome c illustrates the sensitivity of this approach to minor differences in protein sequence. The 2-pL sample volume required for this on-column tryptic digestion is, to our knowledge, the smallest yet reported for a proteolytic assay.

Alkaline treatment of high-solids sludge and its application to anaerobic digestion.

PubMed

Li, Chenchen; Li, Huan; Zhang, Yuyao

2015-01-01

High-solids anaerobic digestion is a promising new process for sludge reduction and bioenergy recovery, requiring smaller digestion tanks and less energy for heating, but a longer digestion time, than traditional low-solids anaerobic digestion. To accelerate this process, alkaline sludge disintegration was tested as a pretreatment method for anaerobic digestion of high-solids sludge. The results showed that alkaline treatment effectively disintegrated both low-solids sludge and high-solids sludge, and treatment duration of 30 min was the most efficient. The relation between sludge disintegration degree and NaOH dose can be described by a transmutative power function model. At NaOH dose lower than 0.2 mol/L, sludge disintegration degree remained virtually unchanged when sludge total solids (TS) content increased from 2.0 to 11.0%, and decreased only slightly when sludge TS increased to 14.2%. Although high-solids sludge required a slightly higher molarity of NaOH to reach the same disintegration level of low-solids sludge, the required mass of NaOH actually decreased due to sludge thickening. From the view of NaOH consumption, sludge TS of 8-12% and a NaOH dose of 0.05 mol/L were optimum conditions for alkaline pretreatment, which resulted in a slight increase in accumulative biogas yield, but a decrease by 24-29% in digestion time during the subsequent anaerobic digestion.

Digestive Diseases

MedlinePlus

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

Roles of magnetite and granular activated carbon in improvement of anaerobic sludge digestion.

PubMed

Peng, Hong; Zhang, Yaobin; Tan, Dongmei; Zhao, Zhiqiang; Zhao, Huimin; Quan, Xie

2018-02-01

Granular activated carbon (GAC) or magnetite could promote methane production from organic wastes, but their roles in enhancing anaerobic sludge digestion have not been clarified. GAC, magnetite and their combination were complemented into sludge digesters, respectively. Experimental results showed that average methane production increased by 7.3% for magnetite, 13.1% for GAC, and 20% for the combination of magnetite and GAC, and the effluent TCOD of the control, magnetite, GAC and magnetite-GAC digesters on day 56 were 53.2, 49.6, 48.0 and 46.6 g/L, respectively. Scanning electron microscope (SEM), nitrogen adsorption, Fourier transform infrared spectroscopy (FTIR) and microbial analysis indicated that magnetite enriched iron-reducing bacteria responsible for sludge hydrolysis while GAC enhanced syntrophic metabolism between iron-reducing bacteria and methanogens due to its high electrical conductivity and large surface area. Supplementing magnetite and GAC together into an anaerobic digester simultaneously accelerated sludge hydrolysis and methane production, resulting in better sludge digestion performance. Copyright © 2017 Elsevier Ltd. All rights reserved.

Defining the Dormant Tumor Microenvironment for Breast Cancer Prevention and Treatment

DTIC Science & Technology

2011-09-01

USAMRMC a. REPORT U b . ABSTRACT U c. THIS PAGE U UU 36 19b. TELEPHONE NUMBER (include area code) 2 TABLE OF CONTENTS...Each group will include 12 rats. b ) Breed rats in the parous group. After parturition, normalize the number of pups to eight. Ten days after...solution ultrasonication assisted tryptic digestion (UATD) method. Parity arm completed. b ) Analyzed the digested mammary ECM samples from

The proteins cleaved by endogenous tryptic proteases in normal EDTA plasma by C18 collection of peptides for liquid chromatography micro electrospray ionization and tandem mass spectrometry.

PubMed

Dufresne, Jaimie; Florentinus-Mefailoski, Angelique; Ajambo, Juliet; Ferwa, Ammara; Bowden, Peter; Marshall, John

2017-01-01

The tryptic peptides from ice cold versus room temperature plasma were identified by C18 liquid chromatography and micro electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Samples collected on ice showed low levels of endogenous tryptic peptides compared to the same samples incubated at room temperature. Plasma on ice contained peptides from albumin, complement, and apolipoproteins and others that were observed by the X!TANDEM and SEQUEST algorithms. In contrast to ice cold samples, after incubation at room temperature, greater numbers of tryptic peptides from well characterized plasma proteins, and from cellular proteins were observed. A total of 583,927 precursor ions and MS/MS spectra were correlated to 94,669 best fit peptides that reduced to 22,287 correlations to the best accession within a gene symbol and to 7174 correlations to at least 510 gene symbols with ≥ 5 independent MS/MS correlations (peptide counts) that showed FDR q-values ranging from E-9 (i.e. FDR = 0.000000001) to E-227. A set of 528 gene symbols identified by X!TANDEM and SEQUEST including C4B showed ≥ fivefold variation between ice cold versus room temperature incubation. STRING analysis of the protein gene symbols observed from endogenous peptides in normal plasma revealed an extensive protein-interaction network of cellular factors associated with cell signalling and regulation, the formation of membrane bound organelles, cellular exosomes and exocytosis network proteins. Taken together the results indicated that a pool of cellular proteins, or protein complexes, in plasma are apparently not stable and degrade soon after incubation at room temperature.

Correlations between air levels of hexahydrophthalic anhydride (HHPA) and HHPA-adducted albumin tryptic peptides in nasal lavage fluid from experimentally exposed volunteers.

PubMed

Kristiansson, Monica H; Lindh, Christian H; Jönsson, Bo A G

2004-01-01

Organic acid anhydrides (OAAs) are low molecular weight, reactive compounds extensively used in industry. Exposure to these compounds may lead to allergic symptoms such as rhinitis and asthma. It is important to develop better and more informative methods for assessment of exposure to OAAs. The aim of this study was to develop a method for analysis of specific hexahydrophthalic anhydride (HHPA)-adducted tryptic peptides of human serum albumin (HSA) in nasal lavage (NAL). Furthermore, these peptides were evaluated as biomarkers of exposure. The proteins in the NAL samples were reduced, alkylated and digested with trypsin and the obtained peptides were analyzed using liquid chromatography/tandem mass spectrometry. The total amount of hydrolyzable HHPA in an HHPA-HSA conjugate was used for calibration. A deuterium-labeled HHPA-HSA conjugate was used as internal standard. Five volunteers were exposed to 10, 40 and 80 microg/m3 of HHPA in an exposure chamber and NAL samples were collected before and after exposure. Acceptable precisions of the assay at 13-14% were found for three adducted peptides. The mean levels of these three peptides for the five subjects ranged between 5-22, 15-75 and 33-125 pmol/mL NAL for the exposures at 10, 40 and 80 microg/m3, respectively. High correlations between air levels and the measured peptides were found on an individual basis but there were large inter-individual differences ranging between 63 and 110% for the three peptides. The large differences remained after protein adjustments. It was possible to detect exposures below 10 microg/m3 with the method. Thus, these adducted peptides may be used as biomarkers of exposure, which may better estimate the risk than previous biomarkers developed for OAAs. Copyright 2004 John Wiley and Sons, Ltd.

Discovery of digestive enzymes in carnivorous plants with focus on proteases.

PubMed

Ravee, Rishiesvari; Mohd Salleh, Faris 'Imadi; Goh, Hoe-Han

2018-01-01

Carnivorous plants have been fascinating researchers with their unique characters and bioinspired applications. These include medicinal trait of some carnivorous plants with potentials for pharmaceutical industry. This review will cover recent progress based on current studies on digestive enzymes secreted by different genera of carnivorous plants: Drosera (sundews), Dionaea (Venus flytrap) , Nepenthes (tropical pitcher plants), Sarracenia (North American pitcher plants) , Cephalotus (Australian pitcher plants) , Genlisea (corkscrew plants) , and Utricularia (bladderworts). Since the discovery of secreted protease nepenthesin in Nepenthes pitcher, digestive enzymes from carnivorous plants have been the focus of many studies. Recent genomics approaches have accelerated digestive enzyme discovery. Furthermore, the advancement in recombinant technology and protein purification helped in the identification and characterisation of enzymes in carnivorous plants. These different aspects will be described and discussed in this review with focus on the role of secreted plant proteases and their potential industrial applications.

Anaerobic co-digestion of commercial food waste and dairy manure: Characterizing biochemical parameters and synergistic effects.

PubMed

Ebner, Jacqueline H; Labatut, Rodrigo A; Lodge, Jeffrey S; Williamson, Anahita A; Trabold, Thomas A

2016-06-01

Anaerobic digestion of commercial food waste is a promising alternative to landfilling commercial food waste. This study characterized 11 types of commercial food wastes and 12 co-digestion blends. Bio-methane potential, biodegradable fraction, and apparent first-order hydrolysis rate coefficients were reported based upon biochemical methane potential (BMP) assays. Food waste bio-methane potentials ranged from 165 to 496 mL CH4/g VS. Substrates high in lipids or readily degradable carbohydrates showed the highest methane production. Average bio-methane potential observed for co-digested substrates was -5% to +20% that of the bio-methane potential of the individual substrates weighted by VS content. Apparent hydrolysis rate coefficients ranged from 0.19d(-1) to 0.65d(-1). Co-digested substrates showed an accelerated apparent hydrolysis rate relative to the weighted average of individual substrate rates. These results provide a database of key bio-digestion parameters to advance modeling and utilization of commercial food waste in anaerobic digestion. Copyright © 2016 Elsevier Ltd. All rights reserved.

Digestive diseases

MedlinePlus

... this page: //medlineplus.gov/ency/article/007447.htm Digestive diseases To use the sharing features on this page, please enable JavaScript. Digestive diseases are disorders of the digestive tract, which ...

Anaerobic digestion of palm oil mill effluent with lampung natural zeolite as microbe immobilization medium and digested cow manure as starter

NASA Astrophysics Data System (ADS)

Halim, Lenny; Mellyanawaty, Melly; Cahyono, Rochim Bakti; Sudibyo, Hanifrahmawan; Budhijanto, Wiratni

2017-05-01

Indonesia is well-known as the world's biggest palm oil producer with 32.5 million tons of annual production. Palm oil processing contributes to 60% wastewater, leading to environmental problem caused by excessive production of wastewater. This wastewater, i.e. Palm Oil Mill Effluent (POME), has high organic content (40,000-60,000 mg COD/L) which is potential for biogas production. However, its low pH value and long chain fatty acid content likely inhibit the anaerobic digestion. Porous media might reduce the inhibitory effect during POME digestion since the media act as both immobilization media for bacteria and as inhibitor adsorbent. Excessive amount of porous media might interfere with the nutrient consumption by microbes. There will be an optimum amount of porous media added, which depends on the wastewater characteristics. This research studied Lampung natural zeolite as immobilization media in digesting POME. The batch experiment was conducted for 40 days with different amount of natural zeolite, i.e. 0; 45; 100; and 200 g/g COD. Digested cow manure was used as the starter inoculum, considering the abundance of anaerobic bacteria therein. Zeolite addition was proven to accelerate COD reduction and stabilized the volatile fatty acid as the intermediate product of anaerobic digestion. The addition of natural zeolite up to 45 g/g COD is considered enough to increase the COD removal (85.695 %), maintain the methane content up to 50%, and enhance the bacteria activity. However, larger amount of natural zeolite lowered the methane production and COD reduction, which indicated nutrient adsorption on to the media and hence caused decreasing nutrient access by the microbes.

Determination of the glycation sites of Bacillus anthracis neoglycoconjugate vaccine by MALDI-TOF/TOF-CID-MS/MS and LC-ESI-QqTOF-tandem mass spectrometry

PubMed Central

Jahouh, Farid; Hou, Shu-jie; Kováč, Pavol; Banoub, Joseph H.

2012-01-01

We present herein an efficient mass spectrometric method for the localization of the glycation sites of a model neoglycoconjugate vaccine formed by a construct of the tetrasaccharide side chain of the Bacillus anthracis exosporium and the protein carrier bovine serum albumin. The glycoconjugate was digested with both trypsin and GluC V8 endoproteinases, and the digests were then analyzed by MALDI-TOF/TOF-CID-MS/MS and nano-LC-ESI-QqTOF-CID-MS/MS. The sequences of the unknown peptides analyzed by MALDI-TOF/TOF-CID-MS/MS, following digestion with the GluC V8 endoproteinase, allowed us to recognize three glycopeptides whose glycation occupancies were, respectively, on Lys 235, Lys 420, and Lys 498. Similarly, the same analysis was performed on the tryptic digests, which permitted us to recognize two glycation sites on Lys 100 and Lys 374. In addition, we have also used LC-ESI-QqTOF-CID-MS/MS analysis for the identification of the tryptic digests. However, this analysis identified a higher number of glycopeptides than would be expected from a glycoconjugate composed of a carbohydrate–protein ratio of 5.4:1, which would have resulted in glycation occupancies of 18 specific sites. This discrepancy was due to the large number of glycoforms formed during the synthetic carbohydrate–spacer–carrier protein conjugation. Likewise, the LC-ESI-QqTOF-MS/MS analysis of the GluC V8 digest also identified 17 different glycation sites on the synthetic glycoconjugate. PMID:22012665

High precision quantification of human plasma proteins using the automated SISCAPA Immuno-MS workflow.

PubMed

Razavi, Morteza; Leigh Anderson, N; Pope, Matthew E; Yip, Richard; Pearson, Terry W

2016-09-25

Efficient robotic workflows for trypsin digestion of human plasma and subsequent antibody-mediated peptide enrichment (the SISCAPA method) were developed with the goal of improving assay precision and throughput for multiplexed protein biomarker quantification. First, an 'addition only' tryptic digestion protocol was simplified from classical methods, eliminating the need for sample cleanup, while improving reproducibility, scalability and cost. Second, methods were developed to allow multiplexed enrichment and quantification of peptide surrogates of protein biomarkers representing a very broad range of concentrations and widely different molecular masses in human plasma. The total workflow coefficients of variation (including the 3 sequential steps of digestion, SISCAPA peptide enrichment and mass spectrometric analysis) for 5 proteotypic peptides measured in 6 replicates of each of 6 different samples repeated over 6 days averaged 3.4% within-run and 4.3% across all runs. An experiment to identify sources of variation in the workflow demonstrated that MRM measurement and tryptic digestion steps each had average CVs of ∼2.7%. Because of the high purity of the peptide analytes enriched by antibody capture, the liquid chromatography step is minimized and in some cases eliminated altogether, enabling throughput levels consistent with requirements of large biomarker and clinical studies. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of recirculation rate on methane production and SEBAR system performance using active stage digester.

PubMed

Tubtong, Cheevanuch; Towprayoon, Sirintornthep; Connor, Michael Anthony; Chaiprasert, Pawinee; Nopharatana, Annop

2010-09-01

A project was undertaken to examine the feasibility of treating organic wastes from Thai fruit and vegetable markets using the sequential batch anaerobic digester (SEBAR) approach. A key feature of the SEBAR system is the regular interchanging, or recirculation, of portions of leachate between each freshly filled digester and a support digester to which it is coupled until it is ready to operate independently. Leachate transfer from this support digester to the fresh waste digester provides additional alkalinity to help counteract the effects of early high acid release rates; it also helps build a balanced microbial population in the fresh waste digester. To optimize the leachate recirculation process, the effect of varying the quantities of leachate interchanged between freshly filled waste digesters and the still highly active support digesters to which they were coupled was studied. It was found that increasing the recirculation rate accelerated the onset of both waste degradation and methane production. The increasing of recirculation rate from 10% to 20% and 10% to 30% could reduce the SEBAR cycle period by approximately 7% and 22% without significant reduction in the amount of methane obtained from the systems. The methane yields were 0.0063, 0.0068 and 0.0077 l g(-1) VS added in the NEW digester per day using leachate recirculation rates of 10%, 20% and 30%, respectively. This finding has potentially important practical and economic implications for those using the SEBAR system to add value to market waste.

Fourier transform infrared spectroscopic studies of the secondary structure and thermal denaturation of CaATPase from rabbit skeletal muscle

NASA Astrophysics Data System (ADS)

Jaworsky, Mark; Brauner, Joseph W.; Mendelsohn, Richard

Fourier transform i.r. spectroscopy has been used to monitor structural alterations induced by thermal denaturation of the intrinsic membrane protein CaATPase in aqueous media. The protein has been isolated, purified and studied in five forms: (i) In its native lipid environment after isolation from rabbit sarcoplasmic reticulum, both in H 2O and D 2O suspensions. (ii) After both mild and extensive tryptic digestion has cleaved those residues external to the membrane bilayer. (iii) Reconstituted in vesicle form with bovine brain sphingomyelin. Fourier deconvolution techniques have been used to enhance the resolution of the intrinsically overlapped Amide I and Amide II spectral regions. Large spectral alterations apparent in the deconvoluted spectra occur in these regions upon thermal denaturation of the protein which are consistent with the formation of a large proportion of β-antiparallel sheet form. The alteration parallels the loss in ATPase activity. A mild tryptic digestion increases slightly the proportion of α-helix and/or random coil secondary structure. A thermal transition to a form containing a high proportion of β structure is still evident. Extensive tryptic digestion nearly abolishes the alpha helical plus random coil secondary structure, while producing a high proportion of β form which is resistant to further thermally induced structural alterations. Studies of CaATPase reconstituted into vesicles with bovine brain sphingomyelin reveal a higher proportion of β structure than the native enzyme, with further introduction of β structure on thermal denaturation. Both the utility of deconvolution techniques and the necessity for caution in their application are apparent from the current experiments.

Accelerator science and technology in Europe: EuCARD 2012

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2012-05-01

Accelerator science and technology is one of a key enablers of the developments in the particle physic, photon physics and also applications in medicine and industry. The paper presents a digest of the research results in the domain of accelerator science and technology in Europe, shown during the third annual meeting of the EuCARD - European Coordination of Accelerator Research and Development. The conference concerns building of the research infrastructure, including in this advanced photonic and electronic systems for servicing large high energy physics experiments. There are debated a few basic groups of such systems like: measurement - control networks of large geometrical extent, multichannel systems for large amounts of metrological data acquisition, precision photonic networks of reference time, frequency and phase distribution.

Digestibility of gluten proteins is reduced by baking and enhanced by starch digestion

PubMed Central

Pan, Xiaoyan; Bellido, Vincent; Toole, Geraldine A.; Gates, Fred K.; Wickham, Martin S. J.; Shewry, Peter R.; Bakalis, Serafim; Padfield, Philip; Mills, E. N. Clare

2015-01-01

Scope Resistance of proteins to gastrointestinal digestion may play a role in determining immune‐mediated adverse reactions to foods. However, digestion studies have largely been restricted to purified proteins and the impact of food processing and food matrices on protein digestibility is poorly understood. Methods and results Digestibility of a total gliadin fraction (TGF), flour (cv Hereward), and bread was assessed using in vitro batch digestion with simulated oral, gastric, and duodenal phases. Protein digestion was monitored by SDS‐PAGE and immunoblotting using monoclonal antibodies specific for celiac‐toxic sequences (QQSF, QPFP) and starch digestion by measuring undigested starch. Whereas the TGF was rapidly digested during the gastric phase the gluten proteins in bread were virtually undigested and digested rapidly during the duodenal phase only if amylase was included. Duodenal starch digestion was also slower in the absence of duodenal proteases. Conclusion The baking process reduces the digestibility of wheat gluten proteins, including those containing sequences active in celiac disease. Starch digestion affects the extent of protein digestion, probably because of gluten‐starch complex formation during baking. Digestion studies using purified protein fractions alone are therefore not predictive of digestion in complex food matrices. PMID:26202208

Digestibility of gluten proteins is reduced by baking and enhanced by starch digestion.

PubMed

Smith, Frances; Pan, Xiaoyan; Bellido, Vincent; Toole, Geraldine A; Gates, Fred K; Wickham, Martin S J; Shewry, Peter R; Bakalis, Serafim; Padfield, Philip; Mills, E N Clare

2015-10-01

Resistance of proteins to gastrointestinal digestion may play a role in determining immune-mediated adverse reactions to foods. However, digestion studies have largely been restricted to purified proteins and the impact of food processing and food matrices on protein digestibility is poorly understood. Digestibility of a total gliadin fraction (TGF), flour (cv Hereward), and bread was assessed using in vitro batch digestion with simulated oral, gastric, and duodenal phases. Protein digestion was monitored by SDS-PAGE and immunoblotting using monoclonal antibodies specific for celiac-toxic sequences (QQSF, QPFP) and starch digestion by measuring undigested starch. Whereas the TGF was rapidly digested during the gastric phase the gluten proteins in bread were virtually undigested and digested rapidly during the duodenal phase only if amylase was included. Duodenal starch digestion was also slower in the absence of duodenal proteases. The baking process reduces the digestibility of wheat gluten proteins, including those containing sequences active in celiac disease. Starch digestion affects the extent of protein digestion, probably because of gluten-starch complex formation during baking. Digestion studies using purified protein fractions alone are therefore not predictive of digestion in complex food matrices. © 2015 The Authors. Molecular Nutrition & Food Research published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Digestive proteolytic and amylolytic activities of Helicoverpa armigera in response to feeding on different soybean cultivars.

PubMed

Naseri, Bahram; Fathipour, Yaghoub; Moharramipour, Saeid; Hosseininaveh, Vahid; Gatehouse, Angharad M R

2010-12-01

Digestive proteolytic and amylolytic activities of the larvae of Helicoverpa armigera (Hübner) fed either on artificial diet or on different soybean cultivars (356, M4, M7, M9, Clark, Sahar, JK, BP, Williams, L17, Zane, Gorgan3 and DPX) and response of the larvae to feeding on some soybean-based protease inhibitors were studied. The highest general and specific proteolytic activities were in artificial-diet-fed larvae. Although the highest general proteolytic activity was in the larvae fed on L17, M4 and Sahar cultivars, the lowest tryptic activity was on L17 and Sahar, which may be due to the presence of some serine protease inhibitors in these two cultivars, resulting in hyperproduction of chymotrypsin- and elastase-like enzymes in response to the inhibition of these enzymes. The highest amylolytic activity was on M4, and the lowest was on Williams and DPX. General proteolytic activity of SKTI-fed larvae was the highest compared with SBBI- and STI-fed larvae. The findings demonstrated that the cultivars L17 and Sahar were partially resistant to this pest, probably because of some secondary chemicals or proteinaceous protease inhibitors of these cultivars.

NOVEL CONTINUOUS PH/SALT GRADIENT AND PEPTIDE SCORE FOR STRONG CATION EXCHANGE CHROMATOGRAPHY IN 2D-NANO-LC/MSMS PEPTIDE IDENTIFICATION FOR PROTEOMICS

EPA Science Inventory

Tryptic digests of human serum albumin (HSA) and human lung epithelial cell lysates were used as test samples in a novel proteomics study. Peptides were separated and analyzed using 2D-nano-LC/MSMS with strong cation exchange (SCX) and reverse phase (RP) chromatography and contin...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belov, Mikhail E.; Anderson, Gordon A.; Smith, Richard D.

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 has been attained formore » rf-only dipolar ejection in a quadrupole operating at a Mathieu parameter q of{approx} 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.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Belov, Mikhail E.; Anderson, Gordon A.; Smith, Richard D.

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 formore » 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.« less

Random and independent sampling of endogenous tryptic peptides from normal human EDTA plasma by liquid chromatography micro electrospray ionization and tandem mass spectrometry.

PubMed

Dufresne, Jaimie; Florentinus-Mefailoski, Angelique; Ajambo, Juliet; Ferwa, Ammara; Bowden, Peter; Marshall, John

2017-01-01

Normal human EDTA plasma samples were collected on ice, processed ice cold, and stored in a freezer at - 80 °C prior to experiments. Plasma test samples from the - 80 °C freezer were thawed on ice or intentionally warmed to room temperature. Protein content was measured by CBBR binding and the release of alcohol soluble amines by the Cd ninhydrin assay. Plasma peptides released over time were collected over C18 for random and independent sampling by liquid chromatography micro electrospray ionization and tandem mass spectrometry (LC-ESI-MS/MS) and correlated with X!TANDEM. Fully tryptic peptides by X!TANDEM returned a similar set of proteins, but was more computationally efficient, than "no enzyme" correlations. Plasma samples maintained on ice, or ice with a cocktail of protease inhibitors, showed lower background amounts of plasma peptides compared to samples incubated at room temperature. Regression analysis indicated that warming plasma to room temperature, versus ice cold, resulted in a ~ twofold increase in the frequency of peptide identification over hours-days of incubation at room temperature. The type I error rate of the protein identification from the X!TANDEM algorithm combined was estimated to be low compared to a null model of computer generated random MS/MS spectra. The peptides of human plasma were identified and quantified with low error rates by random and independent sampling that revealed 1000s of peptides from hundreds of human plasma proteins from endogenous tryptic peptides.

Effect of dosing time on the ammonium nitrogen disinhibition in autothermal thermophilic aerobic digestion for sewage sludge by chemical precipitation.

PubMed

Xu, Changwen; Yuan, Haiping; Lou, Ziyang; Zhang, Guofang; Gong, Junzhe; Zhu, Nanwen

2013-12-01

Magnesium ammonium phosphate (MAP) precipitation was introduced to remove ammonium nitrogen (NH4(+)-N) in autothermal thermophilic aerobic digestion (ATAD) in this study. The dosing time of MgCl2 · 6H2O and NaH2PO4 · 2H2O will influence the removal efficiency of ammonium nitrogen greatly, and the time interval of 2nd, 7th, 12th day were chosen in ATAD process. The lowest NH4(+)-N concentration was found in the 2nd day dosing digester, and 38.37% of VS removal rate was obtained after 12 days digestion, which achieved stabilization 9 days earlier than the non-dosing digester. It revealed that removal of ammonium nitrogen could accelerate the sludge stabilization process. Meanwhile, 49.30% of VS removal rate was found in the 2nd day dosing digester in the 21st day, much higher than that in the non-dosing digester, the 7th day dosing digester, and the 12th day dosing digester, with the corresponding value of 38.37%, 38.38% and 37.04%, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

Information Technology and the Informed Citizen: New Challenges for Government and Libraries. ERIC Digest.

ERIC Educational Resources Information Center

White, Charles S.

Arguing that the foundation of a free civilization is an informed citizenry, this ERIC digest discusses the new challenges faced by the government and libraries in the wake of the Information Age. As electronic technology has accelerated the production and transmission of information, it has become more difficult for the average citizen to access,…

Effect of Acylglycerol Composition and Fatty Acyl Chain Length on Lipid Digestion in pH-Stat Digestion Model and Simulated In Vitro Digestion Model.

PubMed

Qi, Jin F; Jia, Cai H; Shin, Jung A; Woo, Jeong M; Wang, Xiang Y; Park, Jong T; Hong, Soon T; Lee, K-T

2016-02-01

In this study, a pH-stat digestion model and a simulated in vitro digestion model were employed to evaluate the digestion degree of lipids depending on different acylglycerols and acyl chain length (that is, diacylglycerol [DAG] compared with soybean oil representing long-chain triacylglycerol compared with medium-chain triacylglycerol [MCT]). In the pH-stat digestion model, differences were observed among the digestion degrees of 3 oils using digestion rate (k), digestion half-time (t1/2 ), and digestion extent (Φmax). The results showed the digestion rate order was MCT > soybean oil > DAG. Accordingly, the order of digestion half-times was MCT < soybean oil < DAG. In simulated in vitro digestion model, digestion rates (k') and digestion half-times (t'1/2 ) were also obtained and the results showed a digestion rate order of MCT (k' = 0.068 min(-1) ) > soybean oil (k' = 0.037 min(-1) ) > DAG (k' = 0.024 min(-1) ). Consequently, the order of digestion half-times was MCT (t'1/2 = 10.20 min) < soybean oil (t'1/2 = 18.74 min) < DAG (t'1/2 = 29.08 min). The parameters obtained using the 2 models showed MCT was digested faster than soybean oil, and that soybean oil was digested faster than DAG. © 2015 Institute of Food Technologists®

Nanospray FAIMS Fractionation Provides Significant Increases in Proteome Coverage of Unfractionated Complex Protein Digests*

PubMed Central

Swearingen, Kristian E.; Hoopmann, Michael R.; Johnson, Richard S.; Saleem, Ramsey A.; Aitchison, John D.; Moritz, Robert L.

2012-01-01

High-field asymmetric waveform ion mobility spectrometry (FAIMS) is an atmospheric pressure ion mobility technique that can be used to reduce sample complexity and increase dynamic range in tandem mass spectrometry experiments. FAIMS fractionates ions in the gas-phase according to characteristic differences in mobilities in electric fields of different strengths. Undesired ion species such as solvated clusters and singly charged chemical background ions can be prevented from reaching the mass analyzer, thus decreasing chemical noise. To date, there has been limited success using the commercially available Thermo Fisher FAIMS device with both standard ESI and nanoLC-MS. We have modified a Thermo Fisher electrospray source to accommodate a fused silica pulled tip capillary column for nanospray ionization, which will enable standard laboratories access to FAIMS technology. Our modified source allows easily obtainable stable spray at flow rates of 300 nL/min when coupled with FAIMS. The modified electrospray source allows the use of sheath gas, which provides a fivefold increase in signal obtained when nanoLC is coupled to FAIMS. In this work, nanoLC-FAIMS-MS and nanoLC-MS were compared by analyzing a tryptic digest of a 1:1 mixture of SILAC-labeled haploid and diploid yeast to demonstrate the performance of nanoLC-FAIMS-MS, at different compensation voltages, for post-column fractionation of complex protein digests. The effective dynamic range more than doubled when FAIMS was used. In total, 10,377 unique stripped peptides and 1649 unique proteins with SILAC ratios were identified from the combined nanoLC-FAIMS-MS experiments, compared with 6908 unique stripped peptides and 1003 unique proteins with SILAC ratios identified from the combined nanoLC-MS experiments. This work demonstrates how a commercially available FAIMS device can be combined with nanoLC to improve proteome coverage in shotgun and targeted type proteomics experiments. PMID:22186714

Properties of sweetened Indian yogurt (mishti dohi) as affected by added tryptic whey protein hydrolysate.

PubMed

Chatterjee, Alok; Kanawjia, S K; Khetra, Yogesh

2016-01-01

Utilization of Indian sweetened yogurt (colloquially termed as Mishti Dohi), as vehicle for ACE inhibition and antioxidant activity, by added tryptic whey protein hydrolysate (TWPH) (@ 1, 2, 3 % v/milk), was attempted. Yogurt with 3 % TWPH exhibited non-significant (p > 0.05) difference for sensory attributes; but for body & texture; and maximum biofunctional properties, electing it for storage study (5 ± 1 °C). Flavor and body & texture scores registered significant (p < 0.05) decline under 14 days storage. ACE inhibition and antioxidant activity of control increased by 47.95 and 13.18 % and of experimental 24.58 and 13.43 %, correspondingly. Acidity rose to 1.18 % LA. Control samples conveyed 18.07 % and experimental of 20.77 % escalation for wheying-off. Tyrosine value was 27.04 μg.mL(-1). Among rheological attributes, firmness, quantified by texture analyzer TA-XT2i, dropped (p < 0.05), due to decrease of gel rigidity whereas work of adhesion revealed non-significant difference (p > 0.05), throughout.

Two-Dimensional MoS2-Based Zwitterionic Hydrophilic Interaction Liquid Chromatography Material for the Specific Enrichment of Glycopeptides.

PubMed

Xia, Chaoshuang; Jiao, Fenglong; Gao, Fangyuan; Wang, Heping; Lv, Yayao; Shen, Yehua; Zhang, Yangjun; Qian, Xiaohong

2018-06-05

Mass spectrometry (MS)-based glycoproteomics research requires highly efficient sample preparation to eliminate interference from non-glycopeptides and to improve the efficiency of glycopeptide detection. In this work, a novel MoS 2 /Au-NP (gold nanoparticle)-L-cysteine nanocomposite was prepared for glycopeptide enrichment. The two-dimensional (2D) structured MoS 2 nanosheets served as a matrix that could provide a large surface area for immobilizing hydrophilic groups (such as L-cysteine) with low steric hindrance between the materials and the glycopeptides. As a result, the novel nanomaterial possessed an excellent ability to capture glycopeptides. Compared to commercial zwitterionic hydrophilic interaction liquid chromatography (ZIC-HILIC) materials, the novel nanomaterials exhibited excellent enrichment performance with ultrahigh selectivity and sensitivity (approximately 10 fmol), high binding capacity (120 mg g -1 ), high enrichment recovery (more than 93%), satisfying batch-to-batch reproducibility, and good universality for glycopeptide enrichment. In addition, its outstanding specificity and efficiency for glycopeptide enrichment was confirmed by the detection of glycopeptides from an human serum immunoglobulin G (IgG) tryptic digest in quantities as low as a 1:1250 molar ratio of IgG tryptic digest to bovine serum albumin tryptic digest. The novel nanocomposites were further used for the analysis of complex samples, and 1920 glycopeptide backbones from 775 glycoproteins were identified in three replicate analyses of 50 μg of proteins extracted from HeLa cell exosomes. The resulting highly informative mass spectra indicated that this multifunctional nanomaterial-based enrichment method could be used as a promising tool for the in-depth and comprehensive characterization of glycoproteomes in MS-based glycoproteomics.

Digestion proteomics: tracking lactoferrin truncation and peptide release during simulated gastric digestion.

PubMed

Grosvenor, Anita J; Haigh, Brendan J; Dyer, Jolon M

2014-11-01

The extent to which nutritional and functional benefit is derived from proteins in food is related to its breakdown and digestion in the body after consumption. Further, detailed information about food protein truncation during digestion is critical to understanding and optimising the availability of bioactives, in controlling and limiting allergen release, and in minimising or monitoring the effects of processing and food preparation. However, tracking the complex array of products formed during the digestion of proteins is not easily accomplished using classical proteomics. We here present and develop a novel proteomic approach using isobaric labelling to mapping and tracking protein truncation and peptide release during simulated gastric digestion, using bovine lactoferrin as a model food protein. The relative abundance of related peptides was tracked throughout a digestion time course, and the effect of pasteurisation on peptide release assessed. The new approach to food digestion proteomics developed here therefore appears to be highly suitable not only for tracking the truncation and relative abundance of released peptides during gastric digestion, but also for determining the effects of protein modification on digestibility and potential bioavailability.

Why are they missing? : Bioinformatics characterization of missing human proteins.

PubMed

Elguoshy, Amr; Magdeldin, Sameh; Xu, Bo; Hirao, Yoshitoshi; Zhang, Ying; Kinoshita, Naohiko; Takisawa, Yusuke; Nameta, Masaaki; Yamamoto, Keiko; El-Refy, Ali; El-Fiky, Fawzy; Yamamoto, Tadashi

2016-10-21

NeXtProt is a web-based protein knowledge platform that supports research on human proteins. NeXtProt (release 2015-04-28) lists 20,060 proteins, among them, 3373 canonical proteins (16.8%) lack credible experimental evidence at protein level (PE2:PE5). Therefore, they are considered as "missing proteins". A comprehensive bioinformatic workflow has been proposed to analyze these "missing" proteins. The aims of current study were to analyze physicochemical properties, existence and distribution of the tryptic cleavage sites, and to pinpoint the signature peptides of the missing proteins. Our findings showed that 23.7% of missing proteins were hydrophobic proteins possessing transmembrane domains (TMD). Also, forty missing entries generate tryptic peptides were either out of mass detection range (>30aa) or mapped to different proteins (<9aa). Additionally, 21% of missing entries didn't generate any unique tryptic peptides. In silico endopeptidase combination strategy increased the possibility of missing proteins identification. Coherently, using both mature protein database and signal peptidome database could be a promising option to identify some missing proteins by targeting their unique N-terminal tryptic peptide from mature protein database and or C-terminus tryptic peptide from signal peptidome database. In conclusion, Identification of missing protein requires additional consideration during sample preparation, extraction, digestion and data analysis to increase its incidence of identification. Copyright © 2016. Published by Elsevier B.V.

Prediction of in vivo neutral detergent fiber digestibility and digestion rate of potentially digestible neutral detergent fiber: comparison of models.

PubMed

Huhtanen, P; Seppälä, A; Ahvenjärvi, S; Rinne, M

2008-10-01

Eleven 1-pool, seven 2-pool, and three 3-pool models were compared in fitting gas production data and predicting in vivo NDF digestibility and effective first-order digestion rate of potentially digestible NDF (pdNDF). Isolated NDF from 15 grass silages harvested at different stages of maturity was incubated in triplicate in rumen fluid-buffer solution for 72 h to estimate the digestion kinetics from cumulative gas production profiles. In vivo digestibility was estimated by the total fecal collection method in sheep fed at a maintenance level of feeding. The concentration of pdNDF was estimated by a 12-d in situ incubation. The parameter values from gas production profiles and pdNDF were used in a 2-compartment rumen model to predict pdNDF digestibility using 50 h of rumen residence time distributed in a ratio of 0.4:0.6 between the non-escapable and escapable pools. The effective first-order digestion rate was computed both from observed in vivo and model-predicted pdNDF digestibility assuming the passage kinetic model described above. There were marked differences between the models in fitting the gas production data. The fit improved with increasing number of pools, suggesting that silage pdNDF is not a homogenous substrate. Generally, the models predicted in vivo NDF digestibility and digestion rate accurately. However, a good fit of gas production data was not necessarily translated into improved predictions of the in vivo data. The models overestimating the asymptotic gas volumes tended to underestimate the in vivo digestibility. Investigating the time-related residuals during the later phases of fermentation is important when the data are used to estimate the first-order digestion rate of pdNDF. Relatively simple models such as the France model or even a single exponential model with discrete lag period satisfied the minimum criteria for a good model. Further, the comparison of feedstuffs on the basis of parameter values is more unequivocal than in the case

Application of co-anaerobic digester's effluent for sustainable agriculture and aquaculture in the Mekong Delta, Vietnam.

PubMed

Nguyen, V C N; Fricke, K

2015-01-01

This investigation studied the application of digester effluent from co-digestion of pig manure and spent mushroom substrate as a fertilizer for leaf mustard planting and as feed for Tilapia fish growing. The fish raising experiment was set up in 1 × 1 × 1 m hapa conditions (triplicate for each treatment) with the density of 10 individiual per hapa; the fish weight and length were measured every 10 days for 50 continuous days. The leaf mustard was planted in real conditions at farmer's garden with normal cultivation style, and the weight and length of the plant were measured four times during the growing period. The study result shows that the harvest yield of leaf mustard fertilized by the digester effluent was 5.4 times higher than that by an inorganic fertilizer (IF). In addition to its contribution to a higher yield, the digester effluent accelerated the flower formation and shortened cultivation duration. For Tilapia fish culture, the growing rate of fish in the treatments supplied with 50% digester effluent + 50% commercial food (CF) was not significantly different in comparison to the fish cultivation with 100% CF. The result strongly confirms that the digester effluent from a co-digestion biogas plant of pig dung and spent mushroom compost is possible to be used as an organic fertilizer well for not only vegetable planting but also fish culture.

Digested disorder

PubMed Central

DeForte, Shelly; Reddy, Krishna D; Uversky, Vladimir N

2013-01-01

The current literature on intrinsically disordered proteins is overwhelming. To keep interested readers up to speed with this literature, we continue a “Digested Disorder” project and represent a series of reader’s digest type articles objectively representing the research papers and reviews on intrinsically disordered proteins. The only 2 criteria for inclusion in this digest are the publication date (a paper should be published within the covered time frame) and topic (a paper should be dedicated to any aspect of protein intrinsic disorder). The current digest issue covers papers published during the period of April, May, and June of 2013. The papers are grouped hierarchically by topics they cover, and for each of the included paper a short description is given on its major findings. PMID:28516028

Phosphopeptide Enrichment by Covalent Chromatography after Derivatization of Protein Digests Immobilized on Reversed-Phase Supports

PubMed Central

Nika, Heinz; Nieves, Edward; Hawke, David H.; Angeletti, Ruth Hogue

2013-01-01

A rugged sample-preparation method for comprehensive affinity enrichment of phosphopeptides from protein digests has been developed. The method uses a series of chemical reactions to incorporate efficiently and specifically a thiol-functionalized affinity tag into the analyte by barium hydroxide catalyzed β-elimination with Michael addition using 2-aminoethanethiol as nucleophile and subsequent thiolation of the resulting amino group with sulfosuccinimidyl-2-(biotinamido) ethyl-1,3-dithiopropionate. Gentle oxidation of cysteine residues, followed by acetylation of α- and ε-amino groups before these reactions, ensured selectivity of reversible capture of the modified phosphopeptides by covalent chromatography on activated thiol sepharose. The use of C18 reversed-phase supports as a miniaturized reaction bed facilitated optimization of the individual modification steps for throughput and completeness of derivatization. Reagents were exchanged directly on the supports, eliminating sample transfer between the reaction steps and thus, allowing the immobilized analyte to be carried through the multistep reaction scheme with minimal sample loss. The use of this sample-preparation method for phosphopeptide enrichment was demonstrated with low-level amounts of in-gel-digested protein. As applied to tryptic digests of α-S1- and β-casein, the method enabled the enrichment and detection of the phosphorylated peptides contained in the mixture, including the tetraphosphorylated species of β-casein, which has escaped chemical procedures reported previously. The isolates proved highly suitable for mapping the sites of phosphorylation by collisionally induced dissociation. β-Elimination, with consecutive Michael addition, expanded the use of the solid-phase-based enrichment strategy to phosphothreonyl peptides and to phosphoseryl/phosphothreonyl peptides derived from proline-directed kinase substrates and to their O-sulfono- and O-linked β-N-acetylglucosamine (O

A Glycoform of Immunoglobulin G (IgG) as an Early Biomarker of Exposure to Nonhuman Substances

DTIC Science & Technology

2012-12-01

Briefly, 1 mg/mL of purified IgG was incubated at 50 ºC in PBS containing 20 mM dithiothreitol for 2 h and desalted with Biospin P-6 columns (Bio...using dithiothreitol and 2-iodoacetamide, followed by trypsin digestion in ammonium bicarbonate buffer. Tryptic peptides were desalted using a

Rapid Online Non-Enzymatic Protein Digestion Analysis with High Pressure Superheated ESI-MS

NASA Astrophysics Data System (ADS)

Chen, Lee Chuin; Kinoshita, Masato; Noda, Masato; Ninomiya, Satoshi; Hiraoka, Kenzo

2015-07-01

Recently, we reported a new ESI ion source that could electrospray the super-heated aqueous solution with liquid temperature much higher than the normal boiling point ( J. Am. Soc. Mass Spectrom. 25, 1862-1869). The boiling of liquid was prevented by pressurizing the ion source to a pressure greater than atmospheric pressure. The maximum operating pressure in our previous prototype was 11 atm, and the highest achievable temperature was 180°C. In this paper, a more compact prototype that can operate up to 27 atm and 250°C liquid temperatures is constructed, and reproducible MS acquisition can be extended to electrospray temperatures that have never before been tested. Here, we apply this super-heated ESI source to the rapid online protein digestion MS. The sample solution is rapidly heated when flowing through a heated ESI capillary, and the digestion products are ionized by ESI in situ when the solution emerges from the tip of the heated capillary. With weak acid such as formic acid as solution, the thermally accelerated digestion (acid hydrolysis) has the selective cleavage at the aspartate (Asp, D) residue sites. The residence time of liquid within the active heating region is about 20 s. The online operation eliminates the need to transfer the sample from the digestion reactor, and the output of the digestive reaction can be monitored and manipulated by the solution flow rate and heater temperature in a near real-time basis.

Anaerobic Digestion and its Applications

EPA Science Inventory

Anaerobic digestion is a natural biological process. The initials "AD" may refer to the process of anaerobic digestion, or the built systems of anaerobic digesters. While there are many kinds of digesters, the biology is basically the same for all. Anaerobic digesters are built...

Digested disorder

PubMed Central

Reddy, Krishna D; DeForte, Shelly; Uversky, Vladimir N

2014-01-01

The current literature on intrinsically disordered proteins grows fast. To keep interested readers up to speed with this literature, we continue a “Digested Disorder” project and represent a new issue of reader’s digest of the research papers and reviews on intrinsically disordered proteins. The only 2 criteria for inclusion in this digest are the publication date (a paper should be published within the covered time frame) and topic (a paper should be dedicated to any aspect of protein intrinsic disorder). The current digest issue covers papers published during the third quarter of 2013; i.e., during the period of June, July, and September of 2013. Similar to previous issues, the papers are grouped hierarchically by topics they cover, and for each of the included paper a short description is given on its major findings. PMID:28232877

The fate of phenylhydroxylamine in human red cells.

PubMed

Kiese, M; Taeger, K

1976-01-01

Phenylhydroxylamine added to human red cells under aerobic conditions and in the presence of glucose was partly reduced to aniline. About half the hydroxylamine was recovered as amine after a 2-hr incubation. The aniline, after acetylation, was identified as acetanilide by melting point, Rf-value in TCL as well as UV, IR, and NMR spectroscopy. The fate of the remaining phenylhydroxylamine was followed by use of 14C-labeled phenylhydroxylamine. About 30% of the total radioactivity was bound to hemoglobin or other proteins and about 20% was found in highly polar low-molecular substances which were insoluble in organic solvents. The elucidation of the sites at which phenylhydroxylamine was bound to hemoglobin was complicated by the lability of the bonds. When purified human hemoglobin had reacted with radioactive phenylhydroxylamine, large proportions of the radioactivity bound to hemoglobin were removed by treatment with acid or with PMB for separation of alpha- and beta-chains. The radioactive compound liberated from hemoglobin by acid was found to be aniline. After reaction with phenylhydroxylamine the number of SH groups titrable with PMB was found to be diminished. Pretreatment of hemoglobin with N-ethylmaleimide or PMB decreased the amount of phenylhydroxylamine bound to hemoglobin but did not fully prevent the reaction. Tryptic digestion of hemoglobin after reaction with radioactive phenylhydroxylamine yielded tryptic peptides with lower specific activity than that of hemoglobin. Chymotryptic digestion of the tryptic core yielded a core with specific activity much higher than that of hemoglobin. Fingerprinting of the tryptic or chymotryptic hydrolyzates showed the presence of peptides with high and other ones with low or no radioactivity and of radioactive compounds which did not react with ninhydrin. In the covalent binding of phenylhydroxylamine to globin the SH group beta93 plays an important role, but other yet unknown sites are also reactive.

Influence of thermal hydrolysis pretreatment on organic transformation characteristics of high solid anaerobic digestion.

PubMed

Han, Yun; Zhuo, Yang; Peng, Dangcong; Yao, Qian; Li, Huijuan; Qu, Qiliang

2017-11-01

The study evaluated the influence of thermal hydrolysis pretreatment (THP) on anaerobic digestion (AD) ability of high solid sludge. The transformation characteristics of organics during the THP+AD process of dewatering sludge from wastewater treatment plant was investigated using a lab-scale THP reactor and four anaerobic digesters. The reduction efficiency of volatile suspended solids using THP+AD exceeded 49%. The acceleration of biogas production during AD was due to the enhancement of protein hydrolysis and acidogenesis by THP. THP had only minimal influence on the improvement of carbohydrate acidogenesis. The hydrolysis of poly phosphates was likely the main reaction of phosphorus transformation. Biochemical generation of sulfide and ammonia nitrogen occurred during the acidogenesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

Digested disorder: Quarterly intrinsic disorder digest (April-May-June, 2013).

PubMed

DeForte, Shelly; Reddy, Krishna D; Uversky, Vladimir N

2013-01-01

The current literature on intrinsically disordered proteins is overwhelming. To keep interested readers up to speed with this literature, we continue a "Digested Disorder" project and represent a series of reader's digest type articles objectively representing the research papers and reviews on intrinsically disordered proteins. The only 2 criteria for inclusion in this digest are the publication date (a paper should be published within the covered time frame) and topic (a paper should be dedicated to any aspect of protein intrinsic disorder). The current digest issue covers papers published during the period of April, May, and June of 2013. The papers are grouped hierarchically by topics they cover, and for each of the included paper a short description is given on its major findings.

Impact of a multicarbohydrase containing α-galactosidase and xylanase on ileal digestible energy, crude protein digestibility, and ileal amino acid digestibility in broiler chickens.

PubMed

Jasek, A; Latham, R E; Mañón, A; Llamas-Moya, S; Adhikari, R; Poureslami, R; Lee, J T

2018-06-08

Exogenous enzymatic supplementation of poultry feeds, including α-galactosidase and xylanase, has been shown to increase metabolically available energy, although little information has been published on the impact on amino acid digestibility. An experiment was conducted to investigate a multicarbohydrase containing α-galactosidase and xylanase on amino acid digestibility, ileal digestible energy (IDE), and CP in male broiler chicks. The experiment was a 2 × 2 (diet × enzyme) factorial arrangement with 15 replicates of 8 male broilers per replicate raised for 21 d in a battery setting. The 2 dietary treatments included a positive control (PC) and a negative control (NC) diet formulated to contain 2.5% less calculated AME and digestible amino acids. Each of these diets was fed with and without enzyme. Broilers were fed a starter diet from 0-14 d (crumble) and a grower from 14-21 d (pellet). Birds were sampled on day 21 to determine ileal amino acid digestibility, IDE, and CP digestibility. Titanium dioxide (TiO2) was used as an indigestible marker for the determination of digestibility coefficients. Total ileal amino acid digestibility was increased (P = 0.008) by 3.80% with the inclusion of enzyme. Methionine and lysine digestibility was improved (P < 0.05) with the inclusion of enzyme by 3.37% and 2.61%, respectively. Enzyme inclusion increased (P = 0.001) cysteine digestibility by 9.3%. Diet-influenced ileal amino acid digestibility with tryptophan, threonine, isoleucine, and valine digestibility being increased (P < 0.05) in the PC when compared to the NC. IDE was decreased (P = 0.037) in broilers fed the NC diet by 100 kcal/kg feed when compared to broilers fed the PC diet. Enzyme inclusion increased (P = 0.047) IDE value by 90 kcal/kg. Crude protein digestibility was not influenced by diet; however, similar improvements in CP digestibility with enzyme inclusion were observed as with energy. These data support the benefits of a multicarbohydrase containing �

Affinity entrapment of oligosaccharides and glycopeptides using free lectin solution.

PubMed

Yodoshi, Masahiro; Oyama, Takehiro; Masaki, Ken; Kakehi, Kazuaki; Hayakawa, Takao; Suzuki, Shigeo

2011-01-01

Two procedures were proposed for the specific recovery of fluorescent derivatives of glycoprotein-derived oligosaccharides and tryptic glycopeptides using certain plant lectins. The first was based on the salting out of oligosaccharide-lectin conjugates with ammonium sulfate. Oligosaccharides specifically bound to lectins were recovered free from lectins using ethanol precipitation after dissolution in water. This method enabled group separation of 2-aminopyridine-labeled oligosaccharides derived from ovalbumin to galacto-oligosaccharides and agalacto-oligosaccharides by Ricinus communis agglutinin, and to high mannose- and hybrid-type oligosaccharides by wheat-germ agglutinin. Fractional precipitation based on differences in affinity for concanavalin A was accomplished by adding an appropriate concentration of methyl α-mannoside as an inhibitor. In the second method, tryptic digests of glycoproteins were mixed with a lectin solution, and the glycopeptide-lectin conjugates were specifically trapped on a centrifugal ultrafiltration membrane with cut-off of 10 kD. Trapped glycopeptides, as retentates, were passed through membranes by resuspension in diluted acid. This method is particularly useful for the enrichment of glycopeptides in protease digestion mixtures for glycosylation analyses by liquid chromatography-mass spectrometry.

The C-terminal region of alpha-crystallin: involvement in protection against heat-induced denaturation

NASA Technical Reports Server (NTRS)

Takemoto, L.; Emmons, T.; Horwitz, J.; Spooner, B. S. (Principal Investigator)

1993-01-01

Recent studies have demonstrated that the alpha-crystallins can protect other proteins against heat-induced denaturation and aggregation. To determine the possible involvement of the C-terminal region in this activity, the alpha-crystallins were subjected to limited tryptic digestion, and the amount of cleavage from the N-terminal and C-terminal regions of the alpha-A and alpha-B crystallin chains was assessed using antisera specific for these regions. Limited tryptic digestion resulted in cleavage only from the C-terminal region of alpha-A crystallin. This trypsin-treated alpha-A crystallin preparation showed a decreased ability to protect proteins from heat-induced aggregation using an in vitro assay. Together, these results demonstrate that the C-terminal region of alpha-A crystallin is important for its ability to protect against heat-induced aggregation, which is consistent with the hypothesis that post-translational changes that are known to occur at the C-terminal region may have significant effects on the ability of alpha-A crystallin to protect against protein denaturation in vivo.

Digested disorder

PubMed Central

Uversky, Vladimir N

2013-01-01

The current literature on intrinsically disordered proteins is blooming. A simple PubMed search for “intrinsically disordered protein OR natively unfolded protein” returns about 1,800 hits (as of June 17, 2013), with many papers published quite recently. To keep interested readers up to speed with this literature, we are starting a “Digested Disorder” project, which will encompass a series of reader’s digest type of publications aiming at the objective representation of the research papers and reviews on intrinsically disordered proteins. The only two criteria for inclusion in this digest are the publication date (a paper should be published within the covered time frame) and topic (a paper should be dedicated to any aspect of protein intrinsic disorder). The current digest covers papers published during the period of January, February and March of 2013. The papers are grouped hierarchically by topics they cover, and for each of the included paper a short description is given on its major findings. PMID:28516015

Digested disorder: Quarterly intrinsic disorder digest (July-August-September, 2013).

PubMed

Reddy, Krishna D; DeForte, Shelly; Uversky, Vladimir N

2014-01-01

The current literature on intrinsically disordered proteins grows fast. To keep interested readers up to speed with this literature, we continue a "Digested Disorder" project and represent a new issue of reader's digest of the research papers and reviews on intrinsically disordered proteins. The only 2 criteria for inclusion in this digest are the publication date (a paper should be published within the covered time frame) and topic (a paper should be dedicated to any aspect of protein intrinsic disorder). The current digest issue covers papers published during the third quarter of 2013; i.e., during the period of June, July, and September of 2013. Similar to previous issues, the papers are grouped hierarchically by topics they cover, and for each of the included paper a short description is given on its major findings.

Digestive Physiology of Octopus maya and O. mimus: Temporality of Digestion and Assimilation Processes

PubMed Central

Gallardo, Pedro; Olivares, Alberto; Martínez-Yáñez, Rosario; Caamal-Monsreal, Claudia; Domingues, Pedro M.; Mascaró, Maite; Sánchez, Ariadna; Pascual, Cristina; Rosas, Carlos

2017-01-01

Digestive physiology is one of the bottlenecks of octopus aquaculture. Although, there are successful experimentally formulated feeds, knowledge of the digestive physiology of cephalopods is fragmented, and focused mainly on Octopus vulgaris. Considering that the digestive physiology could vary in tropical and sub-tropical species through temperature modulations of the digestive dynamics and nutritional requirements of different organisms, the present review was focused on the digestive physiology timing of Octopus maya and Octopus mimus, two promising aquaculture species living in tropical (22–30°C) and sub-tropical (15–24°C) ecosystems, respectively. We provide a detailed description of how soluble and complex nutrients are digested, absorbed, and assimilated in these species, describing the digestive process and providing insight into how the environment can modulate the digestion and final use of nutrients for these and presumably other octopus species. To date, research on these octopus species has demonstrated that soluble protein and other nutrients flow through the digestive tract to the digestive gland in a similar manner in both species. However, differences in the use of nutrients were noted: in O. mimus, lipids were mobilized faster than protein, while in O. maya, the inverse process was observed, suggesting that lipid mobilization in species that live in relatively colder environments occurs differently to those in tropical ecosystems. Those differences are related to the particular adaptations of animals to their habitat, and indicate that this knowledge is important when formulating feed for octopus species. PMID:28620313

Recognition pattern of thyroglobulin autoantibody from hypothyroid dogs to tryptic peptides of canine thyroglobulin.

PubMed

Tani, Hiroyuki; Shimizu, Reiko; Sasai, Kazumi; Baba, Eiichiroh

2003-10-01

Circulating thyroglobulin autoantibody (TgAA) was analyzed using the Western immunoblot for determination of the dominant epitopes recognized by TgAA on tryptic peptides of canine thyroglobulin (cTg) in hypothyroid dogs. TgAA was measured in hypothyroid dogs, non-hypothyroid dogs with skin diseases and clinically normal dogs. Five of the 7 hypothyroid dogs, 1 of the 8 dogs with skin diseases and 1 of the 4 normal dogs were positive for TgAA. Four of the 5 TgAA-positive hypothyroid dogs were Golden Retrievers, and 3 of them showed high antibody titers. The sera of TgAA positive-dogs reacted to several peptides, and their patterns varied from sample to sample. Sera from 3 dogs with high titers of TgAA reacted broadly to high molecular weight peptides ranging from 45 to 90 kDa. These Western immunoblot patterns of the sera were disappeared after pretreatment with sufficient amount of intact cTg. All serum samples of both TgAA positive dogs and negative controls reacted to low molecular weight peptides ranging from 15 to 20 kDa. These immunoblot patterns of the sera were not disappeared even after pretreatment with sufficient amount of intact cTg. These findings show the possibility that the epitopes recognized by TgAA depend upon individual dogs with hypothyroidism and these autoantibodies recognize conformational epitopes on the cTg molecule.

[Mental disorders in digestive system diseases - internist's and psychiatrist's insight].

PubMed

Kukla, Urszula; Łabuzek, Krzysztof; Chronowska, Justyna; Krzystanek, Marek; Okopień, BogusŁaw

2015-05-01

Mental disorders accompanying digestive system diseases constitute interdisciplinary yet scarcely acknowledged both diagnostic and therapeutic problem. One of the mostly recognized examples is coeliac disease where patients endure the large spectrum of psychopathological symptoms, starting with attention deficit all the way down to the intellectual disability in extreme cases. It has not been fully explained how the pathomechanism of digestive system diseases affects patient's mental health, however one of the hypothesis suggests that it is due to serotonergic or opioid neurotransmission imbalance caused by gluten and gluten metabolites effect on central nervous system. Behavioral changes can also be invoked by liver or pancreatic diseases, which causes life-threatening abnormalities within a brain. It occurs that these abnormalities reflexively exacerbate the symptoms of primary somatic disease and aggravate its course, which worsens prognosis. The dominant mental disease mentioned in this article is depression which because of its effect on a hypothalamuspituitary- adrenal axis and on an autonomic nervous system, not only aggravates the symptoms of inflammatory bowel diseases but may accelerate their onset in genetically predisposed patients. Depression is known to negatively affects patients' ability to function in a society and a quality of their lives. Moreover, as far as children are concerned, the occurrence of digestive system diseases accompanied by mental disorders, may adversely affect their further physical and psychological development, which merely results in worse school performance. All those aspects of mental disorders indicate the desirability of the psychological care for patients with recognized digestive system disease. The psychological assistance should be provided immediately after diagnosis of a primary disease and be continued throughout the whole course of treatment. © 2015 MEDPRESS.

Evaluation of the pepsin digestibility assay for predicting amino acid digestibility of meat and bone meals.

PubMed

Davis, T M; Parsons, C M; Utterback, P L; Kirstein, D

2015-05-01

Sixteen meat and bone meal (MBM) samples were obtained and selected from various company plants to provide a wide range in pepsin nitrogen digestibility values. Pepsin digestibility was determined using either 0.02 or 0.002% pepsin. Amino acid (AA) digestibility of the 16 MBM samples was then determined using a precision-fed cecectomized rooster assay. The 0.02% pepsin digestibility values were numerically higher than the 0.002% pepsin values. The values varied from 77 to 93% for 0.02% pepsin and from 67 to 91% for 0.002% pepsin. The rooster AA digestibility results showed a wide range of values among MBM samples mostly due to the 4 samples having lowest and highest AA digestibility. A precision-fed broiler chick ileal AA digestibility assay confirmed that there were large differences in AA digestibility among the MBM samples having the lowest and highest rooster digestibility values. Correlation analyses between pepsin and AA digestibility values showed that the correlation values (r) were highly significant (P < 0.0001) for all AA when all 16 MBM samples were included in the analysis. However, when the MBM samples with the 2 lowest and the 2 highest rooster digestibility values were not included in the correlation analyses, the correlation coefficient values (r) were generally very low and not significant (P > 0.05). The results indicated that the pepsin nitrogen digestibility assay is only useful for detecting large differences in AA digestibility among MBM. There also was no advantage for using 0.02 versus 0.002% pepsin. © 2015 Poultry Science Association Inc.

Solid anaerobic digestion batch with liquid digestate recirculation and wet anaerobic digestion of organic waste: Comparison of system performances and identification of microbial guilds.

PubMed

Di Maria, Francesco; Barratta, Martino; Bianconi, Francesco; Placidi, Pisana; Passeri, Daniele

2017-01-01

Solid anaerobic digestion batch (SADB) with liquid digestate recirculation and wet anaerobic digestion of organic waste were experimentally investigated. SADB was operated at an organic loading rate (OLR) of 4.55kgVS/m 3 day, generating about 252NL CH 4 /kgVS, whereas the wet digester was operated at an OLR of 0.9kgVS/m 3 day, generating about 320NL CH 4 /kgVS. The initial total volatile fatty acids concentrations for SADB and wet digestion were about 12,500mg/L and 4500mg/L, respectively. There were higher concentrations of ammonium and COD for the SADB compared to the wet one. The genomic analysis performed by high throughput sequencing returned a number of sequences for each sample ranging from 110,619 to 373,307. More than 93% were assigned to the Bacteria domain. Seven and nine major phyla were sequenced for the SADB and wet digestion, respectively, with Bacteroidetes, Firmicutes and Proteobacteria being the dominant phyla in both digesters. Taxonomic profiles suggested a methanogenic pathway characterized by a relevant syntrophic acetate-oxidizing metabolism mainly in the liquid digestate of the SADB. This result also confirms the benefits of liquid digestate recirculation for improving the efficiency of AD performed with high solids (>30%w/w) content. Copyright © 2016 Elsevier Ltd. All rights reserved.

Psychrophilic anaerobic digestion of guinea pig manure in low-cost tubular digesters at high altitude.

PubMed

Garfí, Marianna; Ferrer-Martí, Laia; Villegas, Vidal; Ferrer, Ivet

2011-05-01

Guinea pig is one of the most common livestock in rural communities of the Andes. The aim of this research was to study the anaerobic digestion of guinea pig manure in low-cost unheated tubular digesters at high altitude. To this end, the performance of two pilot digesters was monitored during 7 months; and two greenhouse designs were compared. In the dome roof digester the temperature and biogas production were significantly higher than in the shed roof digester. However, the biogas production rate was low (0.04 m(biogas)(3)m(digester)(-3) d(-1)), which is attributed to the low organic loading rate (0.6 kg(VS)m(digester)(-3)d(-1)) and temperature (23°C) of the system, among other factors. In a preliminary fertilization study, the potato yield per hectare was increased by 100% using the effluent as biofertilizer. Improving manure management techniques, increasing the organic loading rate and co digesting other substrates may be considered to enhance the process. Copyright © 2011 Elsevier Ltd. All rights reserved.

The challenges of anaerobic digestion and the role of biochar in optimizing anaerobic digestion.

PubMed

Fagbohungbe, Michael O; Herbert, Ben M J; Hurst, Lois; Ibeto, Cynthia N; Li, Hong; Usmani, Shams Q; Semple, Kirk T

2017-03-01

Biochar, like most other adsorbents, is a carbonaceous material, which is formed from the combustion of plant materials, in low-zero oxygen conditions and results in a material, which has the capacity to sorb chemicals onto its surfaces. Currently, research is being carried out to investigate the relevance of biochar in improving the soil ecosystem, digestate quality and most recently the anaerobic digestion process. Anaerobic digestion (AD) of organic substrates provides both a sustainable source of energy and a digestate with the potential to enhance plant growth and soil health. In order to ensure that these benefits are realised, the anaerobic digestion system must be optimized for process stability and high nutrient retention capacity in the digestate produced. Substrate-induced inhibition is a major issue, which can disrupt the stable functioning of the AD system reducing microbial breakdown of the organic waste and formation of methane, which in turn reduces energy output. Likewise, the spreading of digestate on land can often result in nutrient loss, surface runoff and leaching. This review will examine substrate inhibition and their impact on anaerobic digestion, nutrient leaching and their environmental implications, the properties and functionality of biochar material in counteracting these challenges. Copyright © 2016 Elsevier Ltd. All rights reserved.

Low cost digester monitoring under realistic conditions: Rural use of biogas and digestate quality.

PubMed

Castro, L; Escalante, H; Jaimes-Estévez, J; Díaz, L J; Vecino, K; Rojas, G; Mantilla, L

2017-09-01

The purpose of this work was to assess the behaviour of anaerobic digestion of cattle manure in a rural digester under realistic conditions, and estimate the quality and properties of the digestate. The data obtained during monitoring indicated that the digester operation was stable without risk of inhibition. It produced an average of 0.85Nm 3 biogas/d at 65.6% methane, providing an energy savings of 76%. In addition, the digestate contained high nutrient concentrations, which is an important feature of fertilizers. However, this method requires post-treatment due to the presence of pathogens. Copyright © 2017 Elsevier Ltd. All rights reserved.

Actinidin enhances protein digestion in the small intestine as assessed using an in vitro digestion model.

PubMed

Kaur, Lovedeep; Rutherfurd, Shane M; Moughan, Paul J; Drummond, Lynley; Boland, Mike J

2010-04-28

This paper describes an in vitro study that tests the proposition that actinidin from green kiwifruit influences the digestion of proteins in the small intestine. Different food proteins, from sources including soy, meat, milk, and cereals, were incubated in the presence or absence of green kiwifruit extract (containing actinidin) using a two-stage in vitro digestion system consisting of an incubation with pepsin at stomach pH (simulating gastric digestion) and then with added pancreatin at small intestinal pH, simulating upper tract digestion in humans. The digests from the small intestinal stage (following the gastric digestion phase) were subjected to gel electrophoresis (SDS-PAGE) to assess loss of intact protein and development of large peptides during the in vitro simulated digestion. Kiwifruit extract influenced the digestion patterns of all of the proteins to various extents. For some proteins, actinidin had little impact on digestion. However, for other proteins, the presence of kiwifruit extract resulted in a substantially greater loss of intact protein and different peptide patterns from those seen after digestion with pepsin and pancreatin alone. In particular, enhanced digestion of whey protein isolate, zein, gluten, and gliadin was observed. In addition, reverse-phase HPLC (RP-HPLC) analysis showed that a 2.5 h incubation of sodium caseinate with kiwifruit extract alone resulted in approximately 45% loss of intact protein.

Digestion and digestive-transport surfaces in cestodes and their fish hosts.

PubMed

Izvekova, G I; Kuperman, B I; Kuz'mina, V V

1997-12-01

The structural and functional organization of digestive-transport surfaces in some lower cestodes and their fish hosts was studied. It has been shown that the ultrastructure of cestode microtriches and fish enterocyte microvilli being the basis of membrane-linked digestion is quite similar. These organelles increase the digestive-transport surfaces both in helminths and fishes. However, the hydrolytic enzyme activity in helminths is usually 2-4 times lower than that of the fishes. Desorption (adsorption) characteristics of various hydrolases in helminths and fishes are also different. In helminths the easily desorbed fraction of each enzyme is always more abundant than in fishes. In contrast, the intensity of transport processes in helminths is higher when compared with fishes. The adaptation of digestive-transport surfaces and enzyme systems to feeding conditions is discussed.

[Gut microbiota and digestion of polysaccharides].

PubMed

El Kaoutari, Abdessamad; Armougom, Fabrice; Raoult, Didier; Henrissat, Bernard

2014-03-01

The distal gut microbiota corresponds to all the microorganisms, essentially bacteria, that reside commonly in the colon. The microbial population is characterized by a large taxonomical diversity, counting approximately a thousand distinct bacterial species for a single individual. The pace of investigations of this microbial system has greatly accelerated these last few years, fuelled by the advent of metagenomics techniques, which do not rely on bacterial cultivation, but utilize high throughput DNA sequencing. In just a few years studies of the intestinal microbiota have become fashionable, albeit with often contradictory results when attempting to correlate changes in microbial composition to diverse pathologies. The article focuses on one of the essential functions of the distal gut microbiota: the digestion of the immense variety of polysaccharides from our diet that enzymes of the host cannot breakdown. © 2014 médecine/sciences – Inserm.

Digested disorder: Quarterly intrinsic disorder digest (January/February/March, 2013).

PubMed

Uversky, Vladimir N

2013-01-01

The current literature on intrinsically disordered proteins is blooming. A simple PubMed search for "intrinsically disordered protein OR natively unfolded protein" returns about 1,800 hits (as of June 17, 2013), with many papers published quite recently. To keep interested readers up to speed with this literature, we are starting a "Digested Disorder" project, which will encompass a series of reader's digest type of publications aiming at the objective representation of the research papers and reviews on intrinsically disordered proteins. The only two criteria for inclusion in this digest are the publication date (a paper should be published within the covered time frame) and topic (a paper should be dedicated to any aspect of protein intrinsic disorder). The current digest covers papers published during the period of January, February and March of 2013. The papers are grouped hierarchically by topics they cover, and for each of the included paper a short description is given on its major findings.

Evaluation of a commercial electro-kinetically pumped sheath-flow nanospray interface coupled to an automated capillary zone electrophoresis system.

PubMed

Peuchen, Elizabeth H; Zhu, Guije; Sun, Liangliang; Dovichi, Norman J

2017-03-01

Capillary zone electrophoresis-electrospray ionization-mass spectrometry (CZE-ESI-MS) is attracting renewed attention for proteomic and metabolomic analysis. An important reason for this interest is the maturation and commercialization of interfaces for coupling CZE with ESI-MS. One of these interfaces is an electro-kinetically pumped sheath flow nanospray interface developed by the Dovichi group, in which a very low sheath flow is generated based on electroosmosis within a glass emitter. CMP Scientific has commercialized this interface as the EMASS-II ion source. In this work, we compared the performance of the EMASS-II ion source with our in-house system. The performance of the systems is equivalent. We also coupled the EMASS-II ion source with a PrinCE Next|480 capillary electrophoresis autosampler and an Orbitrap mass spectrometer, and analyzed this system's performance in terms of sensitivity, reproducibility, and separation performance for separation of tryptic digests, intact proteins, and amino acids. The system produced reproducible analysis of BSA digest; the RSDs of peptide intensity and migration time across 24 runs were less than 20 and 6%, respectively. The system produced a linear calibration curve of intensity across a 30-fold range of tryptic digest concentration. The combination of a commercial autosampler and electrospray interface efficiently separated amino acids, peptides, and intact proteins, and only required 5 μL of sample for analysis. Graphical Abstract The commercial and locally constructed versions of the interface provide similar numbers of protein identifications from a Xenopus laevis fertilized egg digest.

Acid digestion of geological and environmental samples using open-vessel focused microwave digestion.

PubMed

Taylor, Vivien F; Toms, Andrew; Longerich, Henry P

2002-01-01

The application of open vessel focused microwave acid digestion is described for the preparation of geological and environmental samples for analysis using inductively coupled plasma-mass spectrometry (ICP-MS). The method is compared to conventional closed-vessel high pressure methods which are limited in the use of HF to break down silicates. Open-vessel acid digestion more conveniently enables the use of HF to remove Si from geological and plant samples as volatile SiF4, as well as evaporation-to-dryness and sequential acid addition during the procedure. Rock reference materials (G-2 granite, MRG-1 gabbros, SY-2 syenite, JA-1 andesite, and JB-2 and SRM-688 basalts) and plant reference materials (BCR and IAEA lichens, peach leaves, apple leaves, Durham wheat flour, and pine needles) were digested with results comparable to conventional hotplate digestion. The microwave digestion method gave poor results for granitic samples containing refractory minerals, however fusion was the preferred method of preparation for these samples. Sample preparation time was reduced from several days, using conventional hotplate digestion method, to one hour per sample using our microwave method.

Biogas stripping of ammonia from fresh digestate from a food waste digester.

PubMed

Serna-Maza, A; Heaven, S; Banks, C J

2015-08-01

The efficiency of ammonia removal from fresh source-segregated domestic food waste digestate using biogas as a stripping agent was studied in batch experiments at 35, 55 and 70°C, at gas flow rates of 0.125 and 0.250Lbiogasmin(-1)L(-1)digestate with and without pH adjustment. Higher temperatures and alkaline conditions were required for effective ammonia removal, and at 35°C with or without pH adjustment or 55°C with unadjusted pH there was little or no removal. Results were compared to those from earlier studies with digestate that had been stored prior to stripping and showed that ammonia removal from fresh digestate was more difficult, with time constants 1.6-5.7 times higher than those previously reported. This has implications for the design of large-scale systems where continuous stripping of fresh digestate is likely to be the normal operating mode. A mass balance approach showed that thermal-alkaline stripping improved hydrolysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

The function of digestive enzymes on Cu, Zn, and Pb release from soil in in vitro digestion tests.

PubMed

Li, Yi; Demisie, Walelign; Zhang, Ming-kui

2013-07-01

The bioaccessibility of soil heavy metals is the solubility of soil heavy metals in synthetic human digestive juice, which is usually determined using in vitro digestion test. To reveal the effects of digestive enzymes on soil heavy metals bioaccessibility, three representative in vitro digestion tests, Simple Bioaccessibility Extraction Test (SBET), Physiologically Based Extraction Test (PBET), and Simple Gastrointestinal Extraction Test (SGET), were chosen. The bioaccessibility of soil Cu, Zn, and Pb in each method were respectively evaluated with and without digestive enzymes, and the differences were compared. The results showed that the effects of digestive enzymes varied with different methods and elements. Because of digestive enzymes addition, the environmental change from acid gastric phase to neutral intestinal phase of PBET did not result in apparently decrease of the bioaccessibility of soil Cu. However, the solubility of soil Zn and Pb were pH-dependent. For SGET, when digestive enzymes were added, its results reflected more variations resulting from soil and element types. The impacts of digestive enzymes on heavy metal dissolution are mostly seen in the intestinal phase. Therefore, digestive enzyme addition is indispensable to the gastrointestinal digestion methods (PBET and SGET), while the pepsin addition is not important for the methods only comprised of gastric digestion (SBET).

Autoheated thermophilic aerobic digestion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deeny, K.; Hahn, H.; Leonhard, D.

1991-10-01

Autothermal thermophilic aerobic digestion (ATAD) is first and foremost a digestion process, the primary purpose of which is to decompose a portion of the waste organic solids generated from wastewater treatment. As a result of the high operating temperature, digestion is expected to occur within a short time period (6 days) and accomplish a high degree of pathogen reduction. ATAD systems are two-stage aerobic digestion processes that operate under thermophilic temperature conditions (40 to 80C) without supplemental heat. Like composting, the systems rely on the conservation of heat released during digestion itself to attain and sustain the desired operating temperature.more » Typical ATAD systems operate at 55C and may reach temperatures of 60 to 65C in the second-stage reactor. Perhaps because of the high operating temperature, this process has been referred to as Liquid Composting.' Major advantages associated with thermophilic operation include high biological reaction rates and a substantial degree of pathogen reduction.« less

Enhancing post aerobic digestion of full-scale anaerobically digested sludge using free nitrous acid pretreatment.

PubMed

Wang, Qilin; Zhou, Xu; Peng, Lai; Wang, Dongbo; Xie, Guo-Jun; Yuan, Zhiguo

2016-05-01

Post aerobic digestion of anaerobically digested sludge (ADS) has been extensively applied to the wastewater treatment plants to enhance sludge reduction. However, the degradation of ADS in the post aerobic digester itself is still limited. In this work, an innovative free nitrous acid (HNO2 or FNA)-based pretreatment approach is proposed to improve full-scale ADS degradation in post aerobic digester. The post aerobic digestion was conducted by using an activated sludge to aerobically digest ADS for 4 days. Degradations of the FNA-treated (treated at 1.0 and 2.0 mg N/L for 24 h) and untreated ADSs were then determined and compared. The ADS was degraded by 26% and 32%, respectively, in the 4-day post aerobic digestion period while being pretreated at 1.0 and 2.0 mg HNO2-N/L. In comparison, only 20% of the untreated ADS was degraded. Economic analysis demonstrated that the implementation of FNA pretreatment can be economically favourable or not depending on the sludge transport and disposal cost. Copyright © 2016 Elsevier Ltd. All rights reserved.

Long-term thermophilic mono-digestion of rendering wastes and co-digestion with potato pulp.

PubMed

Bayr, S; Ojanperä, M; Kaparaju, P; Rintala, J

2014-10-01

In this study, mono-digestion of rendering wastes and co-digestion of rendering wastes with potato pulp were studied for the first time in continuous stirred tank reactor (CSTR) experiments at 55°C. Rendering wastes have high protein and lipid contents and are considered good substrates for methane production. However, accumulation of digestion intermediate products viz., volatile fatty acids (VFAs), long chain fatty acids (LCFAs) and ammonia nitrogen (NH4-N and/or free NH3) can cause process imbalance during the digestion. Mono-digestion of rendering wastes at an organic loading rate (OLR) of 1.5 kg volatile solids (VS)/m(3)d and hydraulic retention time (HRT) of 50 d was unstable and resulted in methane yields of 450 dm(3)/kg VS(fed). On the other hand, co-digestion of rendering wastes with potato pulp (60% wet weight, WW) at the same OLR and HRT improved the process stability and increased methane yields (500-680 dm(3)/kg VS(fed)). Thus, it can be concluded that co-digestion of rendering wastes with potato pulp could improve the process stability and methane yields from these difficult to treat industrial waste materials. Copyright © 2014 Elsevier Ltd. All rights reserved.

Anaerobic co-digestion of livestock and vegetable processing wastes: fibre degradation and digestate stability.

PubMed

Molinuevo-Salces, Beatriz; Gómez, Xiomar; Morán, Antonio; García-González, Mari Cruz

2013-06-01

Anaerobic digestion of livestock wastes (swine manure (SM) and poultry litter (PL)) and vegetable processing wastes (VPW) mixtures was evaluated in terms of methane yield, volatile solids removal and lignocellulosic material degradation. Batch experiments were performed with 2% VS (volatile solids) to ensure complete conversion of TVFAs (total volatile fatty acids) and to avoid ammonia inhibition. Experimental methane yields obtained for the mixtures resulted in higher values than those obtained from the sum of the methane yields from the individual components. VPW addition to livestock wastes before anaerobic digestion also resulted in improved VS elimination. In SM-VPW co-digestions, CH4 yield increased from 111 to 244 mL CH4 g VS added(-1), and the percentage of VS removed increased from 50% to 86%. For PL-VPW co-digestions, the corresponding values were increased from 158 to 223 mL CH4 g VS added(-1) and from 70% to 92% VS removed. Hemicelluloses and more than 50% of cellulose were degraded during anaerobic digestion. Thermal analyses indicated that the stabilization of the wastes during anaerobic digestion resulted in significantly less energy being released by digestate samples than fresh samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

Economic viability of anaerobic digestion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wellinger, A.

1996-01-01

The industrial application of anaerobic digestion is a relatively new, yet proven waste treatment technology. Anaerobic digestion reduces and upgrades organic waste, and is a good way to control air pollution as it reduces methane and nitrous gas emissions. For environmental and energy considerations, anaerobic digestion is a nearly perfect waste treatment process. However, its economic viability is still in question. A number of parameters - type of waste (solid or liquid), digester system, facility size, product quality and end use, environmental requirements, cost of alternative treatments (including labor), and interest rates - define the investment and operating costs ofmore » an anaerobic digestion facility. Therefore, identical facilities that treat the same amount and type of waste may, depending on location, legislation, and end product characteristics, reveal radically different costs. A good approach for evaluating the economics of anaerobic digestion is to compare it to treatment techniques such as aeration or conventional sewage treatment (for industrial wastewater), or composting and incineration (for solid organic waste). For example, the cost (per ton of waste) of in-vessel composting with biofilters is somewhat higher than that of anaerobic digestion, but the investment costs 1 1/2 to 2 times more than either composting or anaerobic digestion. Two distinct advantages of anaerobic digestion are: (1) it requires less land than either composting or incinerating, which translates into lower costs and milder environmental and community impacts (especially in densely populated areas); and (2) it produces net energy, which can be used to operate the facility or sold to nearby industries.« less

Neutral fat hydrolysis and long-chain fatty acid oxidation during anaerobic digestion of slaughterhouse wastewater.

PubMed

Masse, L; Massé, D I; Kennedy, K J; Chou, S P

2002-07-05

Neutral fat hydrolysis and long-chain fatty acid (LCFA) oxidation rates were determined during the digestion of slaughterhouse wastewater in anaerobic sequencing batch reactors operated at 25 degrees C. The experimental substrate consisted of filtered slaughterhouse wastewater supplemented with pork fat particles at various average initial sizes (D(in)) ranging from 60 to 450 microm. At the D(in) tested, there was no significant particle size effect on the first-order hydrolysis rate. The neutral fat hydrolysis rate averaged 0.63 +/- 0.07 d(-1). LCFA oxidation rate was modelled using a Monod-type equation. The maximum substrate utilization rate (kmax) and the half-saturation concentration (Ks) averaged 164 +/- 37 mg LCFA/L/d and 35 +/- 31 mg LCFA/L, respectively. Pork fat particle degradation was mainly controlled by LCFA oxidation rate and, to a lesser extent, by neutral fat hydrolysis rate. Hydrolysis pretreatment of fat-containing wastewaters and sludges should not substantially accelerate their anaerobic treatment. At a D(in) of 450 microm, fat particles were found to inhibit methane production during the initial 20 h of digestion. Inhibition of methane production in the early phase of digestion was the only significant effect of fat particle size on anaerobic digestion of pork slaughterhouse wastewater. Soluble COD could not be used to determine the rate of lipid hydrolysis due to LCFA adsorption on the biomass.

Modeling a solar-heated anaerobic digester for the developing world using system dynamics

NASA Astrophysics Data System (ADS)

Bentley, Johanna Lynn

Much of the developing world lacks access to a dependable source of energy. Agricultural societies such as Mozambique and Papua New Guinea could sustain a reliable energy source through the microbacterial decomposition of animal and crop waste. Anaerobic digestion produces methane, which can be used directly for heating, cooking, and lighting. Adding a solar component to the digester provides a catalyst for bacteria activity, accelerating digestion and increasing biogas production. Using methane decreases the amount of energy expended by collecting and preparing firewood, eliminates hazardous health effects linked to inhalation of particles, and provides energy close to where it is needed. The purpose of this work is two fold: initial efforts focus on the development and validation of a computer-based system dynamics model that combines elements of the anaerobic digestion process in order to predict methane output; second, the model is flexed to explore how the addition of a solar component increases robustness of the design, examines predicted biogas generation as a function of varying input conditions, and determines how best to configure such systems for use in varying developing world environments. Therefore, the central components of the system: solar insolation, waste feedstock, bacteria population and consumption rates, and biogas production are related both conceptually and mathematically through a serious of equations, conversions, and a causal loop and feedback diagram. Given contextual constraints and initial assumptions for both locations, it was determined that solar insolation and subsequent digester temperature control, amount of waste, and extreme weather patterns had the most significant impact on the system as a whole. Model behavior was both reproducible and comparable to that demonstrated in existing experimental systems. This tool can thus be flexed to fit specific contexts within the developing world to improve the standard of living of many

Changes in chemical composition and digestibility of three maize stover components digested by white-rot fungi.

PubMed

Lynch, J P; O'Kiely, P; Murphy, R; Doyle, E M

2014-08-01

Maize stover (total stem and leaves) is not considered a ruminant feed of high nutritive value. Therefore, an improvement in its digestibility may increase the viability of total forage maize production systems in marginal growth regions. The objective of this study was to describe the changes in chemical composition during the storage of contrasting components of maize stover (leaf, upper stem and lower stem) treated with either of two lignin degrading white-rot fungi (WRF; Pleurotus ostreatus, Trametes versicolor). Three components of maize stover (leaf, upper stem and lower stem), harvested at a conventional maturity for silage production, were digested with either of two WRF for one of four digestion durations (1-4 months). Samples taken prior to fungal inoculation were used to benchmark the changes that occurred. The degradation of acid detergent lignin was observed in all sample types digested with P. ostreatus; however, the loss of digestible substrate in all samples inoculated with P. ostreatus was high, and therefore, P. ostreatus-digested samples had a lower dry matter digestibility than samples prior to inoculation. Similarly, T. veriscolor-digested leaf underwent a non-selective degradation of the rumen-digestible components of fibre. The changes in chemical composition of leaf, upper stem and lower stem digested with either P. ostreatus or T. veriscolor were not beneficial to the feed value of the forage, and incurred high DM losses. Journal of Animal Physiology and Animal Nutrition © 2013 Blackwell Verlag GmbH.

Optimization of Fe2+ supplement in anaerobic digestion accounting for the Fe-bioavailability.

PubMed

Cai, Yafan; Zhao, Xiaoling; Zhao, Yubin; Wang, Hongliang; Yuan, Xufeng; Zhu, Wanbin; Cui, Zongjun; Wang, Xiaofen

2018-02-01

Fe is widely used as an additive in anaerobic digestion, but its bioavailability and the mechanism by which it enhances digestion are unclear. In this study, sequential extraction was used to measure Fe bioavailability, while biochemical parameters, kinetics model and Q-PCR (fluorescence quantitative PCR) were used to explore its mechanism of stimulation. The results showed that sequential extraction is a suitable method to assess the anaerobic system bioavailability of Fe, which is low and fluctuates to a limited extent (1.7 to -3.1wt%), indicating that it would be easy for Fe levels to be insufficient. Methane yield increased when the added Fe 2+ was 10-500mg/L. Appropriate amounts of Fe 2+ accelerated the decomposition of rice straw and facilitated methanogen metabolism, thereby improving reactor performance. The modified Gompertz model better fitted the results than the first-order kinetic model. Feasibility analysis showed that addition of Fe 2+ at ≤50mg/L was suitable. Copyright © 2017. Published by Elsevier Ltd.

Accelerator science and technology in Europe 2008-2017

NASA Astrophysics Data System (ADS)

Romaniuk, Ryszard S.

2013-10-01

European Framework Research Projects have recently added a lot of meaning to the building process of the ERA - the European Research Area. Inside this, the accelerator technology plays an essential role. Accelerator technology includes large infrastructure and intelligent, modern instrumentation embracing mechatronics, electronics, photonics and ICT. During the realization of the European research and infrastructure project FP6 CARE 2004-2008 (Coordinated Accelerator Research in Europe), concerning the development of large accelerator infrastructure in Europe, it was decided that a scientific editorial series of peer-reviewed monographs from this research area will be published in close relation with the projects. It was a completely new and quite brave idea to combine a kind of a strictly research publisher with a transient project, lasting only four or five years. Till then nobody did something like that. The idea turned out to be a real success. The publications now known and valued in the accelerator world, as the (CERN-WUT) Editorial Series on Accelerator Science and Technology, is successfully continued in already the third European project EuCARD2 and has logistic guarantees, for the moment, till the 2017, when it will mature to its first decade. During the realization of the European projects EuCARD (European Coordination for Accelerator R&D 2009-2013 and TIARA (Test Infrastructure of Accelerator Research Area in Europe) there were published 18 volumes in this series. The ambitious plans for the nearest years is to publish, hopefully, a few tens of new volumes. Accelerator science and technology is one of a key enablers of the developments in the particle physic, photon physics and also applications in medicine and industry. The paper presents a digest of the research results in the domain of accelerator science and technology in Europe, published in the monographs of the European Framework Projects (FP) on accelerator technology. The succession of CARE, Eu

Livestock Anaerobic Digester Database

EPA Pesticide Factsheets

The Anaerobic Digester Database provides basic information about anaerobic digesters on livestock farms in the United States, organized in Excel spreadsheets. It includes projects that are under construction, operating, or shut down.

Impact of gastric pH profiles on the proteolytic digestion of mixed βlg-Xanthan biopolymer gels.

PubMed

Dekkers, B L; Kolodziejczyk, E; Acquistapace, S; Engmann, J; Wooster, T J

2016-01-01

The understanding of how foods are digested and metabolised is essential to enable the design/selection of foods as part of a balanced diet. Essential to this endeavour is the development of appropriate biorelevant in vitro digestion tools. In this work, the influence of gastric pH profile on the in vitro digestion of mixtures of β-lactoglobulin (βlg) and xanthan gum prior to and after heat induced gelation was investigated. A conventional highly acidic (pH 1.9) gastric pH profile was compared to two dynamic gastric pH profiles (initial pH of 6.0 vs. 5.2 and H(+) secretion rates of 60 vs. 36 mmol h(-1)) designed to mimic the changes in gastric pH observed during clinical trials with high protein meals. In moving away from the pH 1.9 model, to a pH profile reflecting in vivo conditions, the initial rate and degree of protein digestion halved during the first 45 minutes. After 90 minutes of gastric digestion, all three pH profiles caused similar extents of protein digestion. Given that 50% gastric emptying times of (test) meals are in range of 30-90 min, it would seem highly relevant to use a dynamic pH gastric model rather than a pH 1.9 (USP) or pH 3 model (INFOGEST) in assessing the impact of food structuring approaches on protein digestion. The impact that heat induced gelation had on the degree of gel digestion by pepsin was also investigated. Surprisingly, it was found that heat induced gelation of βlg-xanthan mixtures at 70-90 °C for 20 minutes lead to a considerable decrease in the rate of proteolysis, which contrasts many studies of dispersed aggregates and gels of βlg alone whose heating accelerates pepsin activity due to unfolding. In the present case, the formation of a dense protein network created a fine pore structure which restricted pepsin access into the gel thereby slowing proteolysis. This work not only has implications for the in vitro assessment of protein digestion, but also highlights how protein digestion might be slowed, learnings that

Optimization of solid state anaerobic digestion of the OFMSW by digestate recirculation: A new approach

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michele, Pognani, E-mail: michele.pognani@unimi.it; Giuliana, D’Imporzano, E-mail: giuliana.dimporzano@unimi.it; Gruppo Ricicla - DiSAA, Università degli Studi di Milano, Biomass and Bioenergy Lab., Parco Tecnologico Padano, Via Einstein, Loc. C.na Codazza, 26900 Lodi

2015-01-15

Highlights: • Solid State Anaerobic Digestion (SSAD) of OFMSW can be optimized by irrigation with digestate. • Digestate spreading allows keeping optimal process parameters and high hydrolysis rate. • The 18.4% of CH{sub 4} was produced in the reactor, leaving the 49.7% in the percolate. • Successive CSTR feed with percolate shows a biogas enriched in methane (more than 80%). • The proposed process allow producing the 68% of OFMSW potential CH{sub 4}, getting high quality organic amendment. - Abstract: Dry anaerobic digestion (AD) of OFMSW was optimized in order to produce biogas avoiding the use of solid inoculum. Doingmore » so the dry AD was performed irrigating the solid waste with liquid digestate (flow rate of 1:1.18–1:0.9 w/w waste/digestate; 21 d of hydraulic retention time – HRT) in order to remove fermentation products inhibiting AD process. Results indicated that a high hydrolysis rate of organic matter (OM) and partial biogas production were obtained directly during the dry AD. Hydrolysate OM was removed from digester by the percolate flow and it was subsequently used to feed a liquid anaerobic digester. During dry AD a total loss of 36.9% of total solids was recorded. Methane balance indicated that 18.4% of potential methane can be produced during dry AD and 49.7% by the percolate. Nevertheless results obtained for liquid AD digestion indicated that only 20.4% and 25.7% of potential producible methane was generated by adopting 15 and 20 days of HRT, probably due to the AD inhibition due to high presence of toxic ammonia forms in the liquid medium.« less

Chemical synthesis of biologically active tat trans-activating protein of human immunodeficiency virus type 1.

PubMed Central

Chun, R; Glabe, C G; Fan, H

1990-01-01

Full-length (86-residue) polypeptide corresponding to the human immunodeficiency virus type 1 tat trans-activating protein was chemically synthesized on a semiautomated apparatus, using an Fmoc amino acid continuous-flow strategy. The bulk material was relatively homogeneous, as judged by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and isoelectric focusing, and it showed trans-activating activity when scrape loaded into cells containing a human immunodeficiency virus long terminal repeat-chloramphenicol acetyl-transferase reporter plasmid. Reverse-phase high-pressure liquid chromatography yielded a rather broad elution profile, and assays across the column for biological activity indicated a sharper peak. Thus, high-pressure liquid chromatography provided for enrichment of biological activity. Fast atom bombardment-mass spectrometry of tryptic digests of synthetic tat identified several of the predicted tryptic peptides, consistent with accurate chemical synthesis. Images PMID:2186178

Fabrication of niobium-based oxides/oxynitrides/nitrides and their applications in dye-sensitized solar cells and anaerobic digestion

NASA Astrophysics Data System (ADS)

Zhang, Taihong; Yun, Sining; Li, Xue; Huang, Xinlei; Hou, Yuzhi; Liu, Yanfang; Li, Jing; Zhou, Xiao; Fang, Wen

2017-02-01

Transition metal compounds (TMCs), as a representative family of functional materials, have attracted great attention in the field of renewable energy. Herein, Nb3.49N4.56O0.44 and NbN are prepared from the nitridation of NbO2 in an NH3 atmosphere. These dual-functional Nb-based compounds were applied to dye-sensitized solar cells (DSSCs) and anaerobic digestion (AD), and the efficiency and stability of these DSSCs and AD systems were systematically evaluated. The Nb3.49N4.56O0.44 counter electrode (CE) exhibited considerable electrocatalytic activity and stability in I3- reduction in DSSCs, achieving photovoltaic performance comparable with Pt (6.36% vs. 7.19%). Furthermore, as accelerants, Nb-based compounds can greatly improve the AD environment, increasing substrate utilization and decreasing the hazards in the digestate. Compared with the control sample (409.2 mL/g·VS and 29.55%), substantially higher cumulative biogas production (437.1-522.7 mL/g·VS) and chemical oxygen demand removal rates (56.08%-65.19%) were achieved using Nb-based accelerants in the AD system. The nitridation technique is an effective and general means of converting Nb-based oxides into oxynitrides and nitrides. The Nb-based compounds with high electrocatalytic activities showed promise for DSSCs applications, while greatly enhancing the biodegradability of the AD system as accelerants. These findings could pave the way for multifunctional applications of TMCs in renewable energy fields.

Digestion of chrysanthemum stunt viroid by leaf extracts of Capsicum chinense indicates strong RNA-digesting activity.

PubMed

Iraklis, Boubourakas; Kanda, Hiroko; Nabeshima, Tomoyuki; Onda, Mayu; Ota, Nao; Koeda, Sota; Hosokawa, Munetaka

2016-08-01

CSVd could not infect Nicotiana benthamiana when the plants were pretreated with crude leaf extract of Capsicum chinense 'Sy-2'. C. chinense leaves were revealed to contain strong RNA-digesting activity. Several studies have identified active antiviral and antiviroid agents in plants. Capsicum plants are known to contain antiviral agents, but the mechanism of their activity has not been determined. We aimed to elucidate the mechanism of Capsicum extract's antiviroid activity. Chrysanthemum stunt viroid (CSVd) was inoculated into Nicotiana benthamiana plants before or after treating the plants with a leaf extract of Capsicum chinense 'Sy-2'. CSVd infection was determined using quantitative reverse transcription-polymerase chain reaction (qRT-PCR) 3 weeks after inoculation. When Capsicum extract was sprayed or painted onto N. benthamiana before inoculation, it was effective in preventing infection by CSVd. To evaluate CSVd digestion activity in leaf extracts, CSVd was mixed with leaf extracts of Mirabilis, Phytolacca, Pelargonium and Capsicum. CSVd-digesting activities were examined by quantifying undigested CSVd using qRT-PCR, and RNA gel blotting permitted visualization of the digested CSVd. Only Capsicum leaf extract digested CSVd, and in the Capsicum treatment, small digested CSVd products were detected by RNA gel blot analysis. When the digesting experiment was performed for various cultivars and species of Capsicum, only cultivars of C. chinense showed strong CSVd-digesting activity. Our observations indicated that Capsicum extract contains strong RNA-digesting activity, leading to the conclusion that this activity is the main mechanism for protection from infection by CSVd through spraying or painting before inoculation. To our knowledge, this is the first report of a strong RNA-digesting activity by a plant extract.

Analysis of digester design concepts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ashare, E.; Wilson, E. H.

1979-01-29

Engineering economic analyses were performed on various digester design concepts to determine the relative performance for various biomass feedstocks. A comprehensive literature survey describing the state-of-the-art of the various digestion designs is included. The digester designs included in the analyses are CSTR, plug flow, batch, CSTR in series, multi-stage digestion and biomethanation. Other process options investigated included pretreatment processes such as shredding, degritting, and chemical pretreatment, and post-digestion processes, such as dewatering and gas purification. The biomass sources considered include feedlot manure, rice straw, and bagasse. The results of the analysis indicate that the most economical (on a unit gasmore » cost basis) digester design concept is the plug flow reactor. This conclusion results from this system providing a high gas production rate combined with a low capital hole-in-the-ground digester design concept. The costs determined in this analysis do not include any credits or penalties for feedstock or by-products, but present the costs only for conversion of biomass to methane. The batch land-fill type digester design was shown to have a unit gas cost comparable to that for a conventional stirred tank digester, with the potential of reducing the cost if a land-fill site were available for a lower cost per unit volume. The use of chemical pretreatment resulted in a higher unit gas cost, primarily due to the cost of pretreatment chemical. A sensitivity analysis indicated that the use of chemical pretreatment could improve the economics provided a process could be developed which utilized either less pretreatment chemical or a less costly chemical. The use of other process options resulted in higher unit gas costs. These options should only be used when necessary for proper process performance, or to result in production of a valuable by-product.« less

Effects of Aging on the Digestive System

MedlinePlus

... switch to the Professional version Home Digestive Disorders Biology of the Digestive System Effects of Aging on ... Version. DOCTORS: Click here for the Professional Version Biology of the Digestive System Overview of the Digestive ...

Bi-compartmental elderly or adult dynamic digestion models applied to interrogate protein digestibility.

PubMed

Levi, Carmit Shani; Lesmes, Uri

2014-10-01

The world's population is inevitably ageing thanks to modern progress; however, the development of food and oral formulations tailored to the needs of the elderly is still in its infancy. In vitro digestion models offer high throughput, robust and practically ethics free evaluation of the digestive fate of ingested products. To date, no data have been made publicly available to facilitate the development or application of an in vitro model mirroring the physicochemical conditions of the elderly gastrointestinal system. This study reports the development of a novel and highly bio-relevant in vitro model based on two serially connected bioreactors recreating the dynamic conditions of the adult or elderly alimentary canal. This report and its supplementary material describe in detail the set-up of the system, the applied physicochemical parameters and the development of the controlling software. These are intended to openly depict a versatile platform, which could assist future efforts to develop age-tailored oral formulations. SDS-PAGE analyses of samples collected from the in vitro digestion of β-lactoglobulin, α-lactalbumin and lactoferrin suggest the bioaccessibility of "slow digesting" and "fast digesting" proteins identified in adult models do not necessarily maintain this trait under elderly gastro-intestinal conditions. Overall, this study brings forward a new generic yet advanced model that could facilitate age-tailoring the digestive fate of liquid formulations.

Food waste co-digestion with slaughterhouse waste and sewage sludge: Digestate conditioning and supernatant quality.

PubMed

Borowski, Sebastian; Boniecki, Paweł; Kubacki, Przemysław; Czyżowska, Agata

2018-04-01

In this study, the anaerobic mesophilic co-digestion of food waste (FW) with municipal sewage sludge (MSS) and slaughterhouse waste (SHW) was undertaken in 3-dm 3 laboratory reactors as well as in 50-dm 3 reactors operated in semi-continuous conditions. The highest methane yield of around 0.63 m 3 CH 4 /kgVS fed was achieved for the mixture of FW and SHW treated in the laboratory digester operated at solids retention time (SRT) of 30 days, whereas the co-digestion of FW with MSS under similar operating conditions produced 0.46 m 3 of methane from 1 kgVS fed . No significant differences between methane yields from laboratory digesters and large-scale reactors were reported. The conditioning tests with the digestates from reactor experiments revealed the highest efficiency of inorganic coagulants among all investigated chemicals, which applied in a dose of 10 g/kg allowed to reduce capiliary suction time (CST) of the digestate below 20 s. The combined conditioning with coagulants and bentonite did not further reduce the CST value but improved the quality of the digestate supernatant. In particular, the concentrations of suspended solids, COD as well as metals in the supernatant were considerably lowered. Copyright © 2017. Published by Elsevier Ltd.

Digesters and demographics: identifying support for anaerobic digesters on dairy farms.

PubMed

Sanders, D J; Roberts, M C; Ernst, S C; Thraen, C S

2010-11-01

The dairy industry in the United States is amidst a long-running trend toward fewer, larger dairy farms. This development has created a backlash in some communities over concerns such as odor, waste management, and environmental degradation. Separately, anaerobic digestion has advanced as a waste management technology that potentially offers solutions to some of these issues, providing odor control and a combustible biogas among other things. These digesters require significant capital investments. Voluntary consumer premiums for the renewable energy produced have been used in some instances as a means to move adoption of such systems toward financial feasibility. This project employed a survey to measure Ohio consumers' willingness to pay a premium for renewable energy produced by anaerobic digesters on dairy farms. Cluster analysis was used to segment consumers by willingness to pay, age, education, income, self-identified political inclination, and a composite variable that served as a proxy for respondents' environmental stewardship. Four distinctive groups emerged from the data. Older, less educated respondents were found to have the least amount of support for digesters on dairy farms, whereas politically liberal, environmentally proactive respondents demonstrated the strongest support. Well-educated, affluent respondents and young respondents fell between these 2 groups. Most large dairy farms are generally met with fairly negative responses from their local communities; in contrast, this research finds some popular support for anaerobic digestion technology. Going forward, establishing a positive link between support for anaerobic digesters and for their use on large dairies could open up a new route for less-contested large dairy farm developments. Evaluation of community demographics could become an important part of finding an optimal location for a large dairy farm. Copyright © 2010 American Dairy Science Association. Published by Elsevier Inc. All

Digestibility marker and ileal amino acid digestibility in phytase-supplemented soybean or canola meals for growing pigs.

PubMed

Favero, A; Ragland, D; Vieira, S L; Owusu-Asiedu, A; Adeola, O

2014-12-01

Two experiments using soybean meal (SBM) or canola meal (CM) were conducted to investigate whether the choice of digestibility marker influenced the apparent ileal digestibility (AID) or standardized ileal digestibility (SID) of N and AA in diets supplemented with phytase. In each experiment, 18 barrows fitted with T-cannulas at the ileocecal junction were assigned to 3 diets consisting of a N-free diet to determine endogenous losses of N and AA, a semipurified diet (SBM in Exp. 1 or CM in Exp. 2), and the semipurified diet supplemented with phytase at 1,000 phytase units/kg. Three digestibility markers including acid-insoluble ash (AIA), chromic oxide (Cr2O3), and titanium dioxide (TiO2) were added to each diet at 3 g/kg. Each diet was fed for 7 d, consisting of a 5-d adjustment and a 2-d collection of ileal digesta. In both studies, basal ileal endogenous losses determined with Cr2O3 as a digestibility marker were lower (P<0.01) than with those determined with AIA or TiO2 digestibility markers. Using SBM as the protein source in Exp. 1, there was no interaction between phytase and digestibility marker on AID or SID of AA. The AID of N and AA in SBM using AIA as a digestibility marker tended to be lower (P<0.1) compared with Cr2O3 or TiO2 digestibility markers. Phytase supplementation increased (P<0.001) the AID of Ca and P. The use of AIA or Cr2O3 digestibility marker tended to be associated with lower (P<0.1) SID values compared with TiO2. Phytase did not affect the SID of N or any AA in SBM except for Met, for which there was an increase (P<0.05) with phytase supplementation. Using CM as the protein source in Exp. 2, there were significant interactions between digestibility marker and phytase. Phytase supplementation had effects (P<0.01) on AID or SID when Cr2O3 or TiO2 was used as the digestibility marker. With Cr2O3 or TiO2 as the digestibility marker in the CM diets, phytase supplementation increased (P<0.05) the SID of N and all AA (except Trp). There was

In vivo digestion of bovine milk fat globules: effect of processing and interfacial structural changes. II. Upper digestive tract digestion.

PubMed

Gallier, Sophie; Zhu, Xiang Q; Rutherfurd, Shane M; Ye, Aiqian; Moughan, Paul J; Singh, Harjinder

2013-12-01

The aim of this research was to study the effect of milk processing on the in vivo upper digestive tract digestion of milk fat globules. Fasted rats were serially gavaged over a 5h period with cream from raw, pasteurised, or pasteurised and homogenised milk. Only a few intact dietary proteins and peptides were present in the small intestinal digesta. Significantly (P<0.05) more longer chain (C≥10) fatty acids were present in the digesta of rats gavaged with raw (448 mg g(-1) digesta dry matter (DDM)) and homogenised creams (528 mg g(-1) DDM), as compared to pasteurised and homogenised cream (249 mg g(-1) DDM). Microscopy techniques were used to investigate the structural changes during digestion. Liquid-crystalline lamellar phases surrounding the fat globules, fatty acid soap crystals and lipid-mucin interactions were evident in all small intestinal digesta. Overall, the pasteurised and homogenised cream appeared to be digested to a greater extent. Copyright © 2013 Elsevier Ltd. All rights reserved.

Foaming phenomenon in bench-scale anaerobic digesters.

PubMed

Siebels, Amanda M; Long, Sharon C

2013-04-01

The Madison Metropolitan Sewerage District (The District) in Madison, Wisconsin has been experiencing seasonal foaming in their anaerobic biosolids digesters, which has occurred from mid-November to late June for the past few years. The exact cause(s) of foaming is unknown. Previous research findings are unclear as to whether applications of advanced anaerobic digestion processes reduce the foaming potential of digesters. The object of this study was to investigate how configurations of thermophilic and acid phase-thermophilic anaerobic digestion would affect foaming at the bench-scale level compared to single stage mesophilic digestion for The District. Bench-scale anaerobic digesters were fed with a 4 to 4.5% by dry weight of solids content blend of waste activated sludge (WAS) and primary sludge from The District. Foaming potential was monitored using Alka-Seltzer and aeration foaming tests. The bench-scale acid phase-thermophilic digester had a higher foaming potential than the bench-scale mesophilic digester. These results indicate that higher temperatures increase the foaming potential of the bench-scale anaerobic digesters. The bench-scale acid phase-thermophilic digesters had a greater percent (approximately 5 to 10%) volatile solids destruction and a greater percent (approximately 5 to 10%) total solids destruction when compared to the bench-scale mesophilic digester. Overall, for the full-scale foaming experienced by The District, it appears that adding an acid phase or switching to thermophilic digestion would not alleviate The District's foaming issues.

Impact of different ratios of feedstock to liquid anaerobic digestion effluent on the performance and microbiome of solid-state anaerobic digesters digesting corn stover.

PubMed

Li, Yueh-Fen; Shi, Jian; Nelson, Michael C; Chen, Po-Hsu; Graf, Joerg; Li, Yebo; Yu, Zhongtang

2016-01-01

The objective of this study was to understand how the non-microbial factors of L-AD effluent affected the microbiome composition and successions in the SS-AD digesters using both Illumina sequencing and qPCR quantification of major genera of methanogens. The SS-AD digesters started with a feedstock/total effluent (F/Et) ratio 2.2 (half of the effluent was autoclaved) performed stably, while the SS-AD digesters started with a 4.4 F/Et ratio (no autoclaved effluent) suffered from digester acidification, accumulation of volatile fatty acids, and ceased biogas production two weeks after startup. Some bacteria and methanogens were affected by non-microbial factors of the L-AD fluent. Alkalinity, the main difference between the two F/Et ratios, may be the crucial factor when SS-AD digesters were started using L-AD effluent. Copyright © 2015 Elsevier Ltd. All rights reserved.

Effect of Food Waste Co-Digestion on Digestion, Dewatering, and Cake Quality.

PubMed

Higgins, Matthew; Rajagopalan, Ganesh; Miller, Andre; Brown, Jeffrey; Beightol, Steven

2017-01-01

  The objective of this study was to evaluate the effect of food waste addition on anaerobic digestion performance as well as downstream parameters including dewatering, cake quality, and filtrate quality. Laboratory-scale digesters were fed processed food waste at rates of 25%, 45%, and 65% increased chemical oxygen demand (COD) loading rates compared to a control fed only primary and secondary solids. The specific methane yield increased from 370 L CH4/kg VSadded for the control to 410, 440, and 470 L CH4/kg VSadded for the 25, 45, and 65% food waste addition, respectively. The cake solids after dewatering were all higher for the food waste digesters compared to the control, with the highest cake solids being measured for the 45% food-waste loading. Compared to the control digester, the biosolids odorant concentration increased for the lowest dose of food waste. Odorant concentrations were below detection for the highest food waste loading.

Expanding proteome coverage with orthogonal-specificity α-Lytic proteases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Meyer, Jesse G.; Kim, Sangtae; Maltby, David A.

2014-03-01

Bottom-up proteomics studies traditionally involve proteome digestion with a single protease, trypsin. However, trypsin alone does not generate peptides that encompass the entire proteome. Alternative proteases have been explored, but most have specificity for charged amino acid side chains. Therefore, additional proteases that improve proteome coverage by cleavage at sequences complimentary to trypsin may increase proteome coverage. We demonstrate the novel application of two proteases for bottom-up proteomics: wild type alpha-lytic protease (WaLP), and an active site mutant of WaLP, M190A alpha-lytic protease (MaLP). We assess several relevant factors including MS/MS fragmentation, peptide length, peptide yield, and protease specificity. Bymore » combining data from separate digestions with trypsin, LysC, WaLP, and MaLP, proteome coverage was increased 101% compared to trypsin digestion alone. To demonstrate how the gained sequence coverage can access additional PTM information, we show identification of a number of novel phosphorylation sites in the S. pombe proteome and include an illustrative example from the protein MPD2, wherein two novel sites are identified, one in a tryptic peptide too short to identify and the other in a sequence devoid of tryptic sites. The specificity of WaLP and MaLP for aliphatic amino acid side chains was particularly valuable for coverage of membrane protein sequences, which increased 350% when the data from trypsin, LysC, WaLP, and MaLP were combined.« less

Up-to-date modification of the anaerobic sludge digestion process introducing a separate sludge digestion mode.

PubMed

Sato, K; Ochi, S; Mizuochi, M

2001-01-01

Sewage treatment plants in Japan are subjected to advanced treatment to remove nutrients and hence control eutrophication problems in lakes and bays. This paper discusses the advantages and disadvantages of the separate digestion treatment mode for sludge generated from advanced wastewater treatment. In the separate digestion only primary sludge is digested and the excess activated sludge is directly dewatered. Separate digestion can reduce the return load of nutrients to approximately one third, and has major potential for the beneficial use of sludge.

Production of Hypoallergenic Antibacterial Peptides from Defatted Soybean Meal in Membrane Bioreactor: A Bioprocess Engineering Study with Comprehensive Product Characterization

PubMed Central

2017-01-01

Summary Hypoallergenic antibacterial low-molecular-mass peptides were produced from defatted soybean meal in a membrane bioreactor. In the first step, soybean meal proteins were digested with trypsin in the bioreactor, operated in batch mode. For the tryptic digestion of soybean meal protein, optimum initial soybean meal concentration of 75 g/L, temperature of 40 °C and pH=9.0 were determined. After enzymatic digestion, low-molecular-mass peptides were purified with cross-flow flat sheet membrane (pore size 100 µm) and then with tubular ceramic ultrafiltration membrane (molecular mass cut-off 5 kDa). Effects of transmembrane pressure and the use of a static turbulence promoter to reduce the concentration polarization near the ultrafiltration membrane surface were examined and their positive effects were proven. For the filtration with ultrafiltration membrane, transmembrane pressure of 3·105 Pa with 3-stage discontinuous diafiltration was found optimal. The molecular mass distribution of purified peptides using ultrafiltration membrane was determined by a liquid chromatography–electrospray ionization quadrupole time-of-flight mass spectrometry setup. More than 96% of the peptides (calculated as relative frequency) from the ultrafiltration membrane permeate had the molecular mass M≤1.7 kDa and the highest molecular mass was found to be 3.1 kDa. The decrease of allergenic property due to the tryptic digestion and membrane filtration was determined by an enzyme-linked immunosorbent assay and it was found to exceed 99.9%. It was also found that the peptides purified in the ultrafiltration membrane promoted the growth of Pediococcus acidilactici HA6111-2 and they possessed antibacterial activity against Bacillus cereus. PMID:29089846

Membrane thickening aerobic digestion processes.

PubMed

Woo, Bryen

2014-01-01

Sludge management accounts for approximately 60% of the total wastewater treatment plant expenditure and laws for sludge disposal are becoming increasingly stringent, therefore much consideration is required when designing a solids handling process. A membrane thickening aerobic digestion process integrates a controlled aerobic digestion process with pre-thickening waste activated sludge using membrane technology. This process typically features an anoxic tank, an aerated membrane thickener operating in loop with a first-stage digester followed by second-stage digestion. Membrane thickening aerobic digestion processes can handle sludge from any liquid treatment process and is best for facilities obligated to meet low total phosphorus and nitrogen discharge limits. Membrane thickening aerobic digestion processes offer many advantages including: producing a reusable quality permeate with minimal levels of total phosphorus and nitrogen that can be recycled to the head works of a plant, protecting the performance of a biological nutrient removal liquid treatment process without requiring chemical addition, providing reliable thickening up to 4% solids concentration without the use of polymers or attention to decanting, increasing sludge storage capacities in existing tanks, minimizing the footprint of new tanks, reducing disposal costs, and providing Class B stabilization.

Development of the Digestive System-Experimental Challenges and Approaches of Infant Lipid Digestion.

PubMed

Abrahamse, Evan; Minekus, Mans; van Aken, George A; van de Heijning, Bert; Knol, Jan; Bartke, Nana; Oozeer, Raish; van der Beek, Eline M; Ludwig, Thomas

2012-12-01

At least during the first 6 months after birth, the nutrition of infants should ideally consist of human milk which provides 40-60 % of energy from lipids. Beyond energy, human milk also delivers lipids with a specific functionality, such as essential fatty acids (FA), phospholipids, and cholesterol. Healthy development, especially of the nervous and digestive systems, depends fundamentally on these. Epidemiological data suggest that human milk provides unique health benefits during early infancy that extend to long-lasting benefits. Preclinical findings show that qualitative changes in dietary lipids, i.e., lipid structure and FA composition, during early life may contribute to the reported long-term effects. Little is known in this respect about the development of digestive function and the digestion and absorption of lipids by the newborn. This review gives a detailed overview of the distinct functionalities that dietary lipids from human milk and infant formula provide and the profound differences in the physiology and biochemistry of lipid digestion between infants and adults. Fundamental mechanisms of infant lipid digestion can, however, almost exclusively be elucidated in vitro. Experimental approaches and their challenges are reviewed in depth.

Identification of linker regions and domain borders of the transcription activator protein NtrC from Escherichia coli by limited proteolysis, in-gel digestion, and mass spectrometry.

PubMed

Bantscheff, M; Weiss, V; Glocker, M O

1999-08-24

We have developed a mass spectrometry based method for the identification of linker regions and domain borders in multidomain proteins. This approach combines limited proteolysis and in-gel proteolytic digestions and was applied to the determination of linkers in the transcription factor NtrC from Escherichia coli. Limited proteolysis of NtrC with thermolysin and papain revealed that initial digestion yielded two major bands in SDS-PAGE that were identified by mass spectrometry as the R-domain and the still covalently linked OC-domains. Subsequent steps in limited proteolysis afforded further cleavage of the OC-fragment into the O- and the C-domain at accessible amino acid residues. Mass spectrometric identification of the tryptic/thermolytic peptides obtained after in-gel total proteolysis of the SDS-PAGE-separated domains determined the domain borders and showed that the protease accessible linker between R- and O-domain comprised amino acids Val-131 and Gln-132 within the "Q-linker" in agreement with papain and subtilisin digestion. The region between amino acid residues Thr-389 and Gln-396 marked the hitherto unknown linker sequence that connects the O- with the C-domain. High abundances of proline-, alanine-, serine-, and glutamic acid residues were found in this linker structure (PASE-linker) of related NtrC response regulator proteins. While R- and C-domains remained stable under the applied limited proteolysis conditions, the O-domain was further truncated yielding a core fragment that comprised the sequence from Ile-140 to Arg-320. ATPase activity was lost after separation of the R-domain from the OC-fragment. However, binding of OC- and C- fragments to specific DNA was observed by characteristic band-shifts in migration retardation assays, indicating intact tertiary structures of the C-domain. The outlined strategy proved to be highly efficient and afforded lead information of tertiary structural features necessary for protein design and engineering and

The digestive system: part 1.

PubMed

Johnstone, Carolyn; Hendry, Charles; Farley, Alistair; McLafferty, Ella

This article, which forms part of the life sciences series and is the first of two articles on the digestive system, explores the structure and function of the digestive system. It is important that nurses understand how the digestive system works and its role in maintaining health. The article describes the gross structure of the gastrointestinal tract along with relevant physiology. It also outlines several disorders of the gastrointestinal tract and their treatment and nursing management. The second article will explain the liver, pancreas and gall bladder and their digestive functions, and provides a brief overview of the disorders of chronic liver disease, pancreatitis and gallstones.

Digestibility index and factors affecting rate of starch digestion in vitro in conventional food preparation.

PubMed

Urooj, A; Puttraj, S

1999-02-01

The rate of starch hydrolysis in ten cereal-based food preparations was studied using an in vitro dialysis system. The foods were incubated with human saliva and porcine pancreatin. The sugars released after 3 h digestion were expressed as digestibility index (DI), the percentage starch digested was determined and correlated with the degree of gelatinization (DG). Granule morphology was also investigated and related with starch availability for hydrolysis. Significant differences were observed in the in vitro starch digestibility of the 10 foods (P < 0.05). The DI ranged from 53 for chapathi to 78 for rice flakes. DI was inversely related to the protein (r = -0.79, P < 0.01), fat (r = -0.63, P < 0.05) and energy (r = -0.61, P < 0.01). Percent starch digested was inversely related to the insoluble (r = -0.49, P < 0.05) and total dietary fiber (r = -0.63, P < 0.01) content of the foods. The SEM results provided a better understanding of granular morphology on cooking and the effect of protein on limiting DG. The results suggest that carbohydrate foods of potential use in the therapeutic diets may be identified by their in vitro digestion characteristics.

Digestive enzyme activities in the guts of bonnethead sharks (Sphyrna tiburo) provide insight into their digestive strategy and evidence for microbial digestion in their hindguts.

PubMed

Jhaveri, Parth; Papastamatiou, Yannis P; German, Donovan P

2015-11-01

Few investigations have studied digestive enzyme activities in the alimentary tracts of sharks to gain insight into how these organisms digest their meals. In this study, we examined the activity levels of proteases, carbohydrases, and lipase in the pancreas, and along the anterior intestine, spiral intestine, and colon of the bonnethead shark, Sphyrna tiburo. We then interpreted our data in the context of a rate-yield continuum to discern this shark's digestive strategy. Our data show anticipated decreasing patterns in the activities of pancreatic enzymes moving posteriorly along the gut, but also show mid spiral intestine peaks in aminopeptidase and lipase activities, which support the spiral intestine as the main site of absorption in bonnetheads. Interestingly, we observed spikes in the activity levels of N-acetyl-β-D-glucosaminidase and β-glucosidase in the bonnethead colon, and these chitin- and cellulose-degrading enzymes, respectively, are likely of microbial origin in this distal gut region. Taken in the context of intake and relatively long transit times of food through the gut, the colonic spikes in N-acetyl-β-D-glucosaminidase and β-glucosidase activities suggest that bonnetheads take a yield-maximizing strategy to the digestive process, with some reliance on microbial digestion in their hindguts. This is one of the first studies to examine digestive enzyme activities along the gut of any shark, and importantly, the data match with previous observations that sharks take an extended time to digest their meals (consistent with a yield-maximizing digestive strategy) and that the spiral intestine is the primary site of absorption in sharks. Copyright © 2015 Elsevier Inc. All rights reserved.

Effects of various fiber additions on lipid digestion during in vitro digestion of beef patties.

PubMed

Hur, S J; Lim, B O; Park, G B; Joo, S T

2009-01-01

The purpose of this study was to examine the effect of various fiber additions on lipid digestion during the in vitro digestion of beef patties. The control patties were prepared with 90.5% lean meat and 9.5% tallow. Treatments consisted of 90% lean meat with 9.5% tallow and either 0.5% cellulose, 0.5% chitosan, or 0.5% pectin. The beef patties were then passed through an in vitro digestion model that simulated the composition of the mouth, stomach, and small intestine juices. The change in structure and properties of the lipid droplets was monitored by laser scanning confocal fluorescence microscopy. In general, there was a decrease in lipid droplet diameter as the droplets moved from mouth to stomach to small intestine. The amount of free fatty acid dramatically increased after in vitro digestion in all beef patties. The amount of free fatty acid was, however, lower in beef patties containing chitosan and pectin than other beef patties after in vitro digestion. Beef patties containing various fibers had lower thiobarbituric acid-reactive substances (TBARS) values than samples with no fibers. Among the samples to which fibers were added, chitosan and pectin had lower TBARS than beef patties with cellulose. The cholesterol content decreased after in vitro digestion in all beef patties but was not different among the beef patties before and after in vitro digestion. These results enhance our understanding of the physicochemical and structural changes that occur to ground beef within the gastrointestinal tract.

Sludge stabilization through aerobic digestion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hartman, R.B.; Smith, D.G.; Bennett, E.R.

1979-10-01

The aerobic digestion process with certain modifications is evaluated as an alternative for sludge processing capable of developing a product with characteristics required for land application. Environmental conditions, including temperature, solids concentration, and digestion time, that affect the aerobic digestion of a mixed primary sludge-trickling filter humus are investigated. Variations in these parameters that influence the characteristics of digested sludge are determined, and the parameters are optimized to: provide the maximum rate of volatile solids reduction; develop a stable, nonodorous product sludge; and provide the maximum rate of oxidation of the nitrogenous material present in the feed sludge. (3 diagrams,more » 9 graphs, 15 references, 3 tables)« less

Inclusion of Digestible Surfactants in Solid SMEDDS Formulation Removes Lag Time and Influences the Formation of Structured Particles During Digestion.

PubMed

Vithani, Kapilkumar; Hawley, Adrian; Jannin, Vincent; Pouton, Colin; Boyd, Ben J

2017-05-01

Solid self-microemulsifying drug delivery systems (SMEDDS) have received considerable attention in recent times attempting to overcome the drawbacks of liquid SMEDDS. Earlier literature reports on solid SMEDDS have focussed on formulation development; however, the digestibility and propensity for self-assembly of the digested components with endogenous bile salts and phospholipids are unknown. Therefore, as a starting point, previously reported solid SMEDDS containing Gelucire® 44/14 (GEL) and the non-digestible surfactants, Vitamin E TPGS (TPGS) and Lutrol® F 127 (F 127), were prepared, and their dispersion and digestion behaviours were studied using an in vitro lipolysis model, coupled with small-angle X-ray scattering (SAXS) to determine the formed colloidal structures during digestion in real time. GEL alone was digested (89%) and formed a lamellar phase (Lα). When surfactants were added at a 40:60% w/w lipid to surfactants ratio, digestion was inhibited with a significant lag time being evident. However, increasing the fraction of GEL to 50% w/w enabled digestion with reduced lag time. The substitution of the non-digestible surfactants with digestible surfactants, sucrose esters S-1670 (S-1670) and Span® 60 (S-60), eliminated the digestion lag time, and the formation of colloidal structures was more similar to that of GEL alone.

Anaerobic Digestion. Student Manual. Biological Treatment Process Control.

ERIC Educational Resources Information Center

Carnegie, John W., Ed.

This student manual contains the textual material for a four-lesson unit on anaerobic digestion control. Areas addressed include: (1) anaerobic sludge digestion (considering the nature of raw sludge, purposes of anaerobic digestion, the results of digestion, types of equipment, and other topics); (2) digester process control (considering feeding…

Aerobic sludge digestion under low dissolved oxygen concentrations.

PubMed

Arunachalam, RaviSankar; Shah, Hemant K; Ju, Lu-Kwang

2004-01-01

Low dissolved oxygen (DO) concentrations occur commonly in aerobic digesters treating thickened sludge, with benefits of smaller digester size, much reduced aeration cost, and higher digestion temperature (especially important for plants in colder areas). The effects of low DO concentrations on digestion kinetics were studied using the sludge from municipal wastewater treatment plants in Akron, Ohio, and Los Lunas, New Mexico. The experiments were conducted in both batch digestion and a mixed mode of continuous, fed-batch, and batch operations. The low DO condition was clearly advantageous in eliminating the need for pH control because of the simultaneous occurrence of nitrification and denitrification. However, when compared with fully aerobic (high DO) systems under constant pH control (rare in full-scale plants), low DO concentrations and a higher solids loading had a negative effect on the specific volatile solids (VS) digestion kinetics. Nonetheless, the overall (volumetric) digestion performance depends not only on the specific digestion kinetics, but also the solids concentration, pH, and digester temperature. All of the latter factors favor the low DO digestion of thickened sludge. The significant effect of temperature on low DO digestion was confirmed in the mixed-mode study with the Akron sludge. When compared with the well-known empirical correlation between VS reduction and the product (temperature x solids retention time), the experimental data followed the same trend, but were lower than the correlation predictions. The latter was attributed to the lower digestible VS in the Akron sludge, the slower digestion at low DO concentrations, or both. Through model simulation, the first-order decay constant (kd) was estimated as 0.004 h(-1) in the mixed-mode operations, much lower than those (0.011 to 0.029 h(-1)) obtained in batch digestion. The findings suggested that the interactions among sludges with different treatment ages may have a substantially

Characterisation of protein families in spider digestive fluids and their role in extra-oral digestion.

PubMed

Walter, André; Bechsgaard, Jesper; Scavenius, Carsten; Dyrlund, Thomas S; Sanggaard, Kristian W; Enghild, Jan J; Bilde, Trine

2017-08-10

Spiders are predaceous arthropods that are capable of subduing and consuming relatively large prey items compared to their own body size. For this purpose, spiders have evolved potent venoms to immobilise prey and digestive fluids that break down nutrients inside the prey's body by means of extra-oral digestion (EOD). Both secretions contain an array of active proteins, and an overlap of some components has been anecdotally reported, but not quantified. We systematically investigated the extent of such protein overlap. As venom injection and EOD succeed each other, we further infer functional explanations, and, by comparing two spider species belonging to different clades, assess its adaptive significance for spider EOD in general. We describe the protein composition of the digestive fluids of the mygalomorph Acanthoscurria geniculata and the araneomorph Stegodyphus mimosarum, in comparison with previously published data on a third spider species. We found a number of similar hydrolases being highly abundant in all three species. Among them, members of the family of astacin-like metalloproteases were particularly abundant. While the importance of these proteases in spider venom and digestive fluid was previously noted, we now highlight their widespread use across different spider taxa. Finally, we found species specific differences in the protein overlap between venom and digestive fluid, with the difference being significantly greater in S. mimosarum compared to A. geniculata. The injection of venom precedes the injection with digestive fluid, and the overlap of proteins between venom and digestive fluid suggests an early involvement in EOD. Species specific differences in the overlap may reflect differences in ecology between our two study species. The protein composition of the digestive fluid of all the three species we compared is highly similar, suggesting that the cocktail of enzymes is highly conserved and adapted to spider EOD.

Recovery of failed solid-state anaerobic digesters.

PubMed

Yang, Liangcheng; Ge, Xumeng; Li, Yebo

2016-08-01

This study examined the performance of three methods for recovering failed solid-state anaerobic digesters. The 9-L digesters, which were fed with corn stover, failed at a feedstock/inoculum (F/I) ratio of 10 with negligible methane yields. To recover the systems, inoculum was added to bring the F/I ratio to 4. Inoculum was either added to the top of a failed digester, injected into it, or well-mixed with the existing feedstock. Digesters using top-addition and injection methods quickly resumed and achieved peak yields in 10days, while digesters using well-mixed method recovered slowly but showed 50% higher peak yields. Overall, these methods recovered 30-40% methane from failed digesters. The well-mixed method showed the highest methane yield, followed by the injection and top-addition methods. Recovered digesters outperformed digesters had a constant F/I ratio of 4. Slow mass transfer and slow growth of microbes were believed to be the major limiting factors for recovery. Copyright © 2016 Elsevier Ltd. All rights reserved.

Opposite Electron-Transfer Dissociation and Higher-Energy Collisional Dissociation Fragmentation Characteristics of Proteolytic K/R(X)n and (X)nK/R Peptides Provide Benefits for Peptide Sequencing in Proteomics and Phosphoproteomics.

PubMed

Tsiatsiani, Liana; Giansanti, Piero; Scheltema, Richard A; van den Toorn, Henk; Overall, Christopher M; Altelaar, A F Maarten; Heck, Albert J R

2017-02-03

A key step in shotgun proteomics is the digestion of proteins into peptides amenable for mass spectrometry. Tryptic peptides can be readily sequenced and identified by collision-induced dissociation (CID) or higher-energy collisional dissociation (HCD) because the fragmentation rules are well-understood. Here, we investigate LysargiNase, a perfect trypsin mirror protease, because it cleaves equally specific at arginine and lysine residues, albeit at the N-terminal end. LysargiNase peptides are therefore practically tryptic-like in length and sequence except that following ESI, the two protons are now both positioned at the N-terminus. Here, we compare side-by-side the chromatographic separation properties, gas-phase fragmentation characteristics, and (phospho)proteome sequence coverage of tryptic (i.e., (X) n K/R) and LysargiNase (i.e., K/R(X) n ) peptides using primarily electron-transfer dissociation (ETD) and, for comparison, HCD. We find that tryptic and LysargiNase peptides fragment nearly as mirror images. For LysargiNase predominantly N-terminal peptide ions (c-ions (ETD) and b-ions (HCD)) are formed, whereas for trypsin, C-terminal fragment ions dominate (z-ions (ETD) and y-ions (HCD)) in a homologous mixture of complementary ions. Especially during ETD, LysargiNase peptides fragment into low-complexity but information-rich sequence ladders. Trypsin and LysargiNase chart distinct parts of the proteome, and therefore, the combined use of these enzymes will benefit a more in-depth and reliable analysis of (phospho)proteomes.

Inactivation of selected bacterial pathogens in dairy cattle manure by mesophilic anaerobic digestion (balloon type digester).

PubMed

Manyi-Loh, Christy E; Mamphweli, Sampson N; Meyer, Edson L; Okoh, Anthony I; Makaka, Golden; Simon, Michael

2014-07-14

Anaerobic digestion of animal manure in biogas digesters has shown promise as a technology in reducing the microbial load to safe and recommended levels. We sought to treat dairy manure obtained from the Fort Hare Dairy Farm by investigating the survival rates of bacterial pathogens, through a total viable plate count method, before, during and after mesophilic anaerobic digestion. Different microbiological media were inoculated with different serial dilutions of manure samples that were withdrawn from the biogas digester at 3, 7 and 14 day intervals to determine the viable cells. Data obtained indicated that the pathogens of public health importance were 90%-99% reduced in the order: Campylobacter sp. (18 days) < Escherichia coli sp. (62 days) < Salmonella sp. (133 days) from a viable count of 10.1 × 103, 3.6 × 105, 7.4 × 103 to concentrations below the detection limit (DL = 102 cfu/g manure), respectively. This disparity in survival rates may be influenced by the inherent characteristics of these bacteria, available nutrients as well as the stages of the anaerobic digestion process. In addition, the highest p-value i.e., 0.957 for E. coli showed the statistical significance of its model and the strongest correlation between its reductions with days of digestion. In conclusion, the results demonstrated that the specific bacterial pathogens in manure can be considerably reduced through anaerobic digestion after 133 days.

Current perspective on assessing site of digestion in ruminants.

PubMed

Merchen, N R; Elizalde, J C; Drackley, J K

1997-08-01

The site of nutrient digestion in the gastrointestinal tract of ruminants affects nutrient availability and the nature of digestive end-products supplied to the host animal. Methods to study site of digestion in vivo provide a tool to obtain data that enhance the ability to interpret or predict animal responses to some feeding practices. Examples are discussed for which site of digestion data provided insights that might not have been evident from other approaches. The use of site of digestion techniques may provide interpretation regarding digestion of N by ruminants different from those derived from measurement of total tract N digestion. Site of digestion measurements have been particularly important in studying effects of heat processing of protein sources and in understanding the nature of digestion of N in high-quality, fresh forages. Moreover, site of digestion techniques have been instrumental in interpreting the influences of supplemental fat sources on ruminal digestion and ruminal biohydrogenation and small intestinal digestion of long-chain fatty acids.

Digestive evaluation of soy isolate protein as affected by heat treatment and soy oil inclusion in broilers at an early age.

PubMed

Zhang, Xianglun; Lu, Peng; Xue, Wenyue; Wu, Dawei; Wen, Chao; Zhou, Yanmin

2016-10-01

Soy protein isolate (SPI) mixed with soybean oil (SPIO) incubated at 100°C for 8 h was used to evaluate changes of solubility and digestibility of SPI in vitro and digestive function in broilers at an early age. Arbor Acres broilers were allocated to three groups with six replicates of 12 birds, receiving basal diet (CON), 8 h heat-oxidized SPI diet (HSPI) and 8 h heat-oxidized mixture of SPI and 2% soybean oil diet (HSPIO) for 21 days, respectively. Nitrogen solubility index (NSI) declined and soybean oil accelerated the decline of NSI during incubation (P < 0.05). Decreased in vitro digestibility of dry matter (DM) and crude protein (CP) were observed in SPIO (P < 0.05). HSPI and HSPIO decreased body weight gain, relative jejunum weight and pancreatic trypsin activity at day 21 (P < 0.05). HSPIO decreased anterior intestinal trypsin activity at day 14 and amylase and trypsin activity at day 21, pancreatic amylase activity at day 21 and apparent digestibility of DM, organic matter and CP of broilers from days 18 to 20 (P < 0.05). Heat treatment and soybean oil could induce oxidative modification of SPI, and oxidized SPI negatively affected growth and digestion of broilers. © 2016 Japanese Society of Animal Science. © 2016 Japanese Society of Animal Science.

The dynamic changes and interactional networks of prokaryotic community between co-digestion and mono-digestions of corn stalk and pig manure.

PubMed

Wang, Min; Zhang, Xueying; Zhou, Jun; Yuan, Yuexiang; Dai, Yumei; Li, Dong; Li, Zhidong; Liu, Xiaofeng; Yan, Zhiying

2017-02-01

Anaerobic co-digestion is considered to be an efficient way to improve the biogas production. The abundance, dynamic and interactional networks of prokaryotic community were investigated between co-digestion and mono-digestions of corn stalk and pig manure in mesophilic batch test. Co-digestion showed higher methane production, and contributed to suitable microenvironment as well as stable prokaryotic community structure. The highest methane production was achieved with the highest relative abundance of Methanosaeta. Prokaryotic community in mono-digestions might inhibited by FA or FVFA. The functional modules in co-digestion and mono-digestion of pig manure clustered together with bigger size and higher degree, and the connections of metabolic functions were better-organized, which means high-efficient utilization of substrate and prevention of the two digestion systems crash. The partial mantel tests showed the functional modules were significantly affected by environmental factors. These results further explained that why co-digestion was more efficient than mono-digestion owing to suitable microenvironment. Copyright © 2016 Elsevier Ltd. All rights reserved.

Digestibility of Bovine Serum Albumin and Peptidomics of the Digests: Effect of Glycation Derived from α-Dicarbonyl Compounds.

PubMed

Sheng, Bulei; Larsen, Lotte Bach; Le, Thao T; Zhao, Di

2018-03-21

α-Dicarbonyl compounds, which are widely generated during sugar fragmentation and oil oxidation, are important precursors of advanced glycation end products (AGEs). In this study, the effect of glycation derived from glyoxal (GO), methylglyoxal (MGO) and diacetyl (DA) on the in vitro digestibility of bovine serum albumin (BSA) was investigated. Glycation from α-dicarbonyl compounds reduced digestibility of BSA in both gastric and intestinal stage of digestion according to measurement of degree of hydrolysis. Changes in peptide composition of digests induced by glycation were displayed, showing absence of peptides, occurrence of new peptides and formation of peptide-AGEs, based on the results obtained using liquid chromatography electron-spray-ionization tandem mass spectrometry (LC-ESI-MS/MS). Crosslinked glycation structures derived from DA largely reduced the sensitivity of glycated BSA towards digestive proteases based on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) results. Network structures were found to remain in the digests of glycated samples by transmission electron microscope (TEM), thus the impact of AGEs in unabsorbed digests on the gut flora should be an interest for further studies.

Pressurized Pepsin Digestion in Proteomics

PubMed Central

López-Ferrer, Daniel; Petritis, Konstantinos; Robinson, Errol W.; Hixson, Kim K.; Tian, Zhixin; Lee, Jung Hwa; Lee, Sang-Won; Tolić, Nikola; Weitz, Karl K.; Belov, Mikhail E.; Smith, Richard D.; Paša-Tolić, Ljiljana

2011-01-01

Integrated top-down bottom-up proteomics combined with on-line digestion has great potential to improve the characterization of protein isoforms in biological systems and is amendable to high throughput proteomics experiments. Bottom-up proteomics ultimately provides the peptide sequences derived from the tandem MS analyses of peptides after the proteome has been digested. Top-down proteomics conversely entails the MS analyses of intact proteins for more effective characterization of genetic variations and/or post-translational modifications. Herein, we describe recent efforts toward efficient integration of bottom-up and top-down LC-MS-based proteomics strategies. Since most proteomics separations utilize acidic conditions, we exploited the compatibility of pepsin (where the optimal digestion conditions are at low pH) for integration into bottom-up and top-down proteomics work flows. Pressure-enhanced pepsin digestions were successfully performed and characterized with several standard proteins in either an off-line mode using a Barocycler or an on-line mode using a modified high pressure LC system referred to as a fast on-line digestion system (FOLDS). FOLDS was tested using pepsin and a whole microbial proteome, and the results were compared against traditional trypsin digestions on the same platform. Additionally, FOLDS was integrated with a RePlay configuration to demonstrate an ultrarapid integrated bottom-up top-down proteomics strategy using a standard mixture of proteins and a monkey pox virus proteome. PMID:20627868

Trypsin and MALDI matrix pre-coated targets simplify sample preparation for mapping proteomic distributions within biological tissues by imaging mass spectrometry

PubMed Central

Zubair, Faizan; Laibinis, Paul E.; Swisher, William G.; Yang, Junhai; Spraggins, Jeffrey M.; Norris, Jeremy L.; Caprioli, Richard M.

2017-01-01

Prefabricated surfaces containing α-cyano-4-hydroxycinnamic acid and trypsin have been developed to facilitate enzymatic digestion of endogenous tissue proteins prior to matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS). Tissue sections are placed onto slides that were previously coated with α-cyano-4-hydroxycinnamic acid and trypsin. After incubation to promote enzymatic digestion, the tissue is analyzed by MALDI IMS to determine the spatial distribution of the tryptic fragments. The peptides detected in the MALDI IMS dataset were identified by Liquid chromatography-tandem mass spectrometry/mass spectrometry. Protein identification was further confirmed by correlating the localization of unique tryptic fragments originating from common parent proteins. Using this procedure, proteins with molecular weights as large as 300 kDa were identified and their distributions were imaged in sections of rat brain. In particular, large proteins such as myristoylated alanine-rich C-kinase substrate (29.8 kDa) and spectrin alpha chain, non-erythrocytic 1 (284 kDa) were detected that are not observed without trypsin. The pre-coated targets simplify workflow and increase sample throughput by decreasing the sample preparation time. Further, the approach allows imaging at higher spatial resolution compared with robotic spotters that apply one drop at a time. PMID:27676701

High-Throughput Characterization of Intrinsic Disorder in Proteins from the Protein Structure Initiative

PubMed Central

Johnson, Derrick E.; Xue, Bin; Sickmeier, Megan D.; Meng, Jingwei; Cortese, Marc S.; Oldfield, Christopher J.; Le Gall, Tanguy; Dunker, A. Keith; Uversky, Vladimir N.

2012-01-01

The identification of intrinsically disordered proteins (IDPs) among the targets that fail to form satisfactory crystal structures in the Protein Structure Initiative represent a key to reducing the costs and time for determining three-dimensional structures of proteins. To help in this endeavor, several Protein Structure Initiative Centers were asked to send samples of both crystallizable proteins and proteins that failed to crystallize. The abundance of intrinsic disorder in these proteins was evaluated via computational analysis using Predictors of Natural Disordered Regions (PONDR®) and the potential cleavage sites and corresponding fragments were determined. Then, the target proteins were analyzed for intrinsic disorder by their resistance to limited proteolysis. The rates of tryptic digestion of sample target proteins were compared to those of lysozyme/myoglobin, apo-myoglobin and α-casein as standards of ordered, partially disordered and completely disordered proteins, respectively. At the next stage, the protein samples were subjected to both far-UV and near-UV circular dichroism (CD) analysis. For most of the samples, a good agreement between CD data, predictions of disorder and the rates of limited tryptic digestion was established. Further experimentation is being performed on a smaller subset of these samples in order to obtain more detailed information on the ordered/disordered nature of the proteins. PMID:22651963

Conservation of an ATP-binding domain among recA proteins from Proteus vulgaris, erwinia carotovora, Shigella flexneri, and Escherichia coli K-12 and B/r

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knight, K.L.; Hess, R.M.; McEntee, K.

1988-06-01

The purified RecA proteins encoded by the cloned genes from Proteus vulgaris, Erwinia carotovora, Shigella flexneri, and Escherichia coli B/r were compared with the RecA protein from E. coli K-12. Each of the proteins hydrolyzed ATP in the presence of single-stranded DNA, and each was covalently modified with the photoaffinity ATP analog 8-azidoadenosine 5'-triphosphate (8N/sub 3/ATP). Two-dimensional tryptic maps of the four heterologous RecA proteins demonstrated considerable structural conservation among these bacterial genera. Moreover, when the (..cap alpha..-/sup 32/P)8N/sub 3/ATP-modified proteins were digested with trypsin and analyzed by high-performance liquid chromatography, a single peak of radioactivity was detected in eachmore » of the digests and these peptides eluted identically with the tryptic peptide T/sub 31/ of the E. coli K-12 RecA protein, which was the unique site of 8N/sub 3/ATP photolabeling. Each of the heterologous recA genes hybridized to oligonucleotide probes derived from the ATP-binding domain sequence of the E. coli K-12 gene. These last results demonstrate that the ATP-binding domain of the RecA protein has been strongly conserved for greater than 10/sup 7/ years.« less

Automation of nanoflow liquid chromatography-tandem mass spectrometry for proteome analysis by using a strong cation exchange trap column.

PubMed

Jiang, Xiaogang; Feng, Shun; Tian, Ruijun; Han, Guanghui; Jiang, Xinning; Ye, Mingliang; Zou, Hanfa

2007-02-01

An approach was developed to automate sample introduction for nanoflow LC-MS/MS (microLC-MS/MS) analysis using a strong cation exchange (SCX) trap column. The system consisted of a 100 microm id x 2 cm SCX trap column and a 75 microm id x 12 cm C18 RP analytical column. During the sample loading step, the flow passing through the SCX trap column was directed to waste for loading a large volume of sample at high flow rate. Then the peptides bound on the SCX trap column were eluted onto the RP analytical column by a high salt buffer followed by RP chromatographic separation of the peptides at nanoliter flow rate. It was observed that higher performance of separation could be achieved with the system using SCX trap column than with the system using C18 trap column. The high proteomic coverage using this approach was demonstrated in the analysis of tryptic digest of BSA and yeast cell lysate. In addition, this system was also applied to two-dimensional separation of tryptic digest of human hepatocellular carcinoma cell line SMMC-7721 for large scale proteome analysis. This system was fully automated and required minimum changes on current microLC-MS/MS system. This system represented a promising platform for routine proteome analysis.

Functional Utrastructure of Genlisea (Lentibulariaceae) Digestive Hairs

PubMed Central

Płachno, Bartosz Jan; Kozieradzka-Kiszkurno, Małgorzata; Świątek, Piotr

2007-01-01

Background and Aims Digestive structures of carnivorous plants produce external digestive enzymes, and play the main role in absorption. In Lentibulariaceae, the ultrastructure of digestive hairs has been examined in some detail in Pinguicula and Utricularia, but the sessile digestive hairs of Genlisea have received very little attention so far. The aim of this study was to fill this gap by expanding their morphological, anatomical and histochemical characterization. Methods Several imaging techniques were used, including light, confocal and electron microscopy, to reveal the structure and function of the secretory hairs of Genlisea traps. This report demonstrates the application of cryo-SEM for fast imaging of whole, physically fixed plant secretory structures. Key Results and Conclusion The concentration of digestive hairs along vascular bundles in subgenus Genlisea is a primitive feature, indicating its basal position within the genus. Digestive hairs of Genlisea consist of three compartments with different ultrastructure and function. In subgenus Tayloria the terminal hair cells are transfer cells, but not in species of subgenus Genlisea. A digestive pool of viscous fluid occurs in Genlisea traps. In spite of their similar architecture, the digestive-absorptive hairs of Lentibulariaceae feature differences in morphology and ultrastructure. PMID:17550910

Digestive Enzyme Supplementation in Gastrointestinal Diseases.

PubMed

Ianiro, Gianluca; Pecere, Silvia; Giorgio, Valentina; Gasbarrini, Antonio; Cammarota, Giovanni

2016-01-01

Digestive enzymes are able to break down proteins and carbohydrates and lipids, and their supplementation may play a role in the management of digestive disorders, from lactose intolerance to cystic fibrosis. To date, several formulations of digestive enzymes are available on the market, being different each other in terms of enzyme type, source and origin, and dosage. This review, performed through a non-systematic search of the available literature, will provide an overview of the current knowledge of digestive enzyme supplementation in gastrointestinal disorders, discussion of the use of pancreatic enzymes, lactase (β-galactosidase) and conjugated bile acids, and also exploring the future perspective of digestive enzyme supplementation. Currently, the animal-derived enzymes represent an established standard of care, however the growing study of plant-based and microbe-derived enzymes offers great promise in the advancement of digestive enzyme therapy. New frontiers of enzyme replacement are being evaluated also in the treatment of diseases not specifically related to enzyme deficiency, whereas the combination of different enzymes might constitute an intriguing therapeutic option in the future.

Dietary acrylamide: What happens during digestion.

PubMed

Sansano, M; Heredia, A; Peinado, I; Andrés, A

2017-12-15

Acrylamide is a well-known potentially carcinogen compound formed during thermal processing as an intermediate of Maillard reactions. Three objectives were addressed: the impact of gastric digestion on acrylamide content of French Fries, chips, chicken nuggets, onions rings, breakfast cereals, biscuits, crackers, instant coffee and coffee substitute; the acrylamide content evolution during gastrointestinal digestion of French fries and chips; and the effectiveness of blanching and air-frying on acrylamide mitigation after gastrointestinal digestion. A significant increase (p-value <0.05) in acrylamide content was observed for most of the products after gastric digestion (maximum registered for sweet biscuits, from 30±8 to 150±48µg/kg). However, at the end of the intestinal stage, acrylamide values were statistically similar (p-value=0.132) for French fries and lower than the initial values (before digestion) in potato chips (p-value=0.027). Finally, the low acrylamide content found in blanched and air-fried samples, remained still lower than for deep fried samples even after gastrointestinal digestion. Copyright © 2017 Elsevier Ltd. All rights reserved.

Digestive oncologist in the gastroenterology training curriculum

PubMed Central

Mulder, Chris Jacob Johan; Peeters, Marc; Cats, Annemieke; Dahele, Anna; Droste, Jochim Terhaar sive

2011-01-01

Until the late 1980s, gastroenterology (GE) was considered a subspecialty of Internal Medicine. Today, GE also incorporates Hepatology. However, Digestive Oncology training is poorly defined in the Hepatogastroenterology (HGE)-curriculum. Therefore, a Digestive Oncology curriculum should be developed and this document might be a starting point for such a curriculum. HGE-specialists are increasingly resisting the paradigm in which they play only a diagnostic and technical role in the management of digestive tumors. We suggest minimum end-points in the standard HGE-curriculum for oncology, and recommend a focus year in the Netherlands for Digestive Oncology in the HGE-curriculum. To produce well-trained digestive oncologists, an advanced Digestive Oncology training program with specific qualifications in Digestive Oncology (2 years) has been developed. The schedule in Belgium includes a period of at least 6 mo to be spent in a medical oncology department. The goal of these programs remains the production of well-trained digestive oncologists. HGE specialists are part of the multidisciplinary oncological teams, and some have been administering chemotherapy in their countries for years. In this article, we provide a road map for the organization of a proper training in Digestive Oncology. We hope that the World Gastroenterology Organisation and other (inter)national societies will support the necessary certifications for this specific training in the HGE-curriculum. PMID:21556128

[Determination of Fe, Ti and V in vanadium and titanium magnetite by ICP-OES and microwave-assisted digestion].

PubMed

Zhu, Xia-ping; Yin, Ji-xian; Chen, Wei-dong; Hu, Zi-Wen; Liang, Qing-xun; Chen, Tie-yao

2010-08-01

The method of determination of iron, titanium and vanadium in indissolvable vanadium and titanium magnetite has been established by inductively coupled plasma atomic emission spectroscopy through adding the complexant A and using microwave-assisted digestion. The optimal conditions are confirmed by orthogonal experiment: 0.1 g vanadium and titanium magnetite, 0.04 g complexant A, 12 mL concentrated HC1, 10 min digestion time, and 385 W microwave power. The newly-established method has been applied to digest vanadium and titanium magnetite of Panzhihua Iron and Steel Institute (GBW07226). The iron, titanium and vanadium were detected by ICP-OES, and both comparative error (Er%) and comparative standard deviation (RSD%) met the demand of analytical chemistry, and the complexant A can significantly accelerate the dissolution of vanadium and titanium magnetite through the complexation with the dissolved metal ions, and making the surface of sample and hydrochloric acid medium to update constantly. The determination of the main and trace elements of digestion solution at the same time was achieved by ICP-OES. The method has the advantages of less use of reagents, economy, rapidness, and being friendly to environment, and it meets the requirement for rapid and volume determination. So the method has the value of practical application for the entry-exit inspection and quarantine department of the state and other relevant inspection units.

Digestibility of fucosylated glycosaminoglycan from sea cucumber and its effects on digestive enzymes under simulated salivary and gastrointestinal conditions.

PubMed

Zhao, Longyan; Qin, Yujing; Guan, Ruowei; Zheng, Wenqi; Liu, Jikai; Zhao, Jinhua

2018-04-15

The digestibility of fucosylated glycosaminoglycan (FG) and its effects on digestive enzymes were investigated using an in vitro digestion model. Results showed that the molecular weight and the reducing sugar content of FG were not significantly changed, and no free monosaccharides released from FG were detected after the salivary, gastric and intestinal digestion, indicating that both the backbone and the sulfated fucose branches of FG are resistant to be cleaved in the saliva and gastrointestinal tract environments. Furthermore, FG can dose-dependently inhibit digestive enzymes such as α-amylase, pepsin and pancreatic lipase in different degrees under the simulated digestion conditions due to the sulfate and carboxyl groups. These physiological effects of FG may help control the postprandial glucose concentration and have the potential in the prevention or treatment of reflux disease and obesity. The findings may provide information on the digestibility and beneficial physiological effects of FG as a potential natural product to promote human health. Copyright © 2018 Elsevier Ltd. All rights reserved.

Digestive Diseases

MedlinePlus

... Process Research Training & Career Development Funded Grants & Grant History Research Resources Research at NIDDK Technology Advancement & Transfer Meetings & Workshops Health Information Diabetes Digestive ...

Inactivation of Selected Bacterial Pathogens in Dairy Cattle Manure by Mesophilic Anaerobic Digestion (Balloon Type Digester)

PubMed Central

Manyi-Loh, Christy E.; Mamphweli, Sampson N.; Meyer, Edson L.; Okoh, Anthony I.; Makaka, Golden; Simon, Michael

2014-01-01

Anaerobic digestion of animal manure in biogas digesters has shown promise as a technology in reducing the microbial load to safe and recommended levels. We sought to treat dairy manure obtained from the Fort Hare Dairy Farm by investigating the survival rates of bacterial pathogens, through a total viable plate count method, before, during and after mesophilic anaerobic digestion. Different microbiological media were inoculated with different serial dilutions of manure samples that were withdrawn from the biogas digester at 3, 7 and 14 day intervals to determine the viable cells. Data obtained indicated that the pathogens of public health importance were 90%–99% reduced in the order: Campylobacter sp. (18 days) < Escherichia coli sp. (62 days) < Salmonella sp. (133 days) from a viable count of 10.1 × 103, 3.6 × 105, 7.4 × 103 to concentrations below the detection limit (DL = 102 cfu/g manure), respectively. This disparity in survival rates may be influenced by the inherent characteristics of these bacteria, available nutrients as well as the stages of the anaerobic digestion process. In addition, the highest p-value i.e., 0.957 for E. coli showed the statistical significance of its model and the strongest correlation between its reductions with days of digestion. In conclusion, the results demonstrated that the specific bacterial pathogens in manure can be considerably reduced through anaerobic digestion after 133 days. PMID:25026086

High-solids anaerobic co-digestion of sewage sludge and food waste in comparison with mono digestions: stability and performance.

PubMed

Dai, Xiaohu; Duan, Nina; Dong, Bin; Dai, Lingling

2013-02-01

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 0.50 d(-1), respectively. Experimental data of co-digestion were in good conformity to the predictions of the model. Copyright © 2012 Elsevier Ltd. All rights reserved.

Predicting the apparent viscosity and yield stress of mixtures of primary, secondary and anaerobically digested sewage sludge: Simulating anaerobic digesters.

PubMed

Markis, Flora; Baudez, Jean-Christophe; Parthasarathy, Rajarathinam; Slatter, Paul; Eshtiaghi, Nicky

2016-09-01

Predicting the flow behaviour, most notably, the apparent viscosity and yield stress of sludge mixtures inside the anaerobic digester is essential because it helps optimize the mixing system in digesters. This paper investigates the rheology of sludge mixtures as a function of digested sludge volume fraction. Sludge mixtures exhibited non-Newtonian, shear thinning, yield stress behaviour. The apparent viscosity and yield stress of sludge mixtures prepared at the same total solids concentration was influenced by the interactions within the digested sludge and increased with the volume fraction of digested sludge - highlighted using shear compliance and shear modulus of sludge mixtures. However, when a thickened primary - secondary sludge mixture was mixed with dilute digested sludge, the apparent viscosity and yield stress decreased with increasing the volume fraction of digested sludge. This was caused by the dilution effect leading to a reduction in the hydrodynamic and non-hydrodynamic interactions when dilute digested sludge was added. Correlations were developed to predict the apparent viscosity and yield stress of the mixtures as a function of the digested sludge volume fraction and total solids concentration of the mixtures. The parameters of correlations can be estimated using pH of sludge. The shear and complex modulus were also modelled and they followed an exponential relationship with increasing digested sludge volume fraction. Copyright © 2016 Elsevier Ltd. All rights reserved.

Anaerobic co-digestion of recalcitrant agricultural wastes: Characterizing of biochemical parameters of digestate and its impacts on soil ecosystem.

PubMed

Muscolo, Adele; Settineri, Giovanna; Papalia, Teresa; Attinà, Emilio; Basile, Carmelo; Panuccio, Maria Rosaria

2017-05-15

Anaerobic digestion (AD) of organic wastes is a promising alternative to landfilling for reducing Greenhouse Gas Emission (GHG) and it is encouraged by current regulation in Europe. Biogas-AD produced, represents a useful source of green energy, while its by-product (digestate) is a waste, that needs to be safely disposal. The sustainability of anaerobic digestion plants partly depends on the management of their digestion residues. This study has been focused on the environmental and economic benefits of co-digest recalcitrant agricultural wastes such olive wastes and citrus pulp, in combination with livestock wastes, straw and cheese whey for biogas production. The aim of this work was to investigate the effects of two different bioenergy by-products on soil carbon stock, enzymes involved in nutrient cycling and microbial content. The two digestates were obtained from two plants differently fed: the first plant (Uliva) was powered with 60% of recalcitrant agricultural wastes, and 40% of livestock manure milk serum and maize silage. The second one (Fattoria) was fed with 40% of recalcitrant agricultural wastes and 60% of livestock manure, milk serum and maize silage. Each digestate, separated in liquid and solid fractions, was added to the soil at different concentrations. Our results evidenced that mixing and type of input feedstock affected the composition of digestates. Three months after treatments, our results showed that changes in soil chemical and biochemical characteristics depended on the source of digestate, the type of fraction and the concentration used. The mainly affected soil parameters were: Soil Organic Matter (SOM), Microbial Biomass Carbon (MBC), Fluorescein Diacetate Hydrolysis (FDA), Water Soluble Phenol (WSP) and Catalase (CAT) that can be used to assess the digestate agronomical feasibility. These results show that the agronomic quality of a digestate is strictly dependent on percentage and type of feedstocks that will be used to power the

Infant digestion physiology and the relevance of in vitro biochemical models to test infant formula lipid digestion.

PubMed

Poquet, Laure; Wooster, Tim J

2016-08-01

Lipids play an important role in the diet of preterm and term infants providing a key energy source and essential lipid components for development. While a lot is known about adult lipid digestion, our understanding of infant digestion physiology is still incomplete, the greatest gap being on the biochemistry of the small intestine, particularly the activity and relative importance of the various lipases active in the intestine. The literature has been reviewed to identify the characteristics of lipid digestion of preterm and term infants, but also to better understand the physiology of the infant gastrointestinal tract compared to adults that impacts the absorption of lipids. The main differences are a higher gastric pH, submicellar bile salt concentration, a far more important role of gastric lipases as well as differences at the level of the intestinal barrier. Importantly, the consequences of improper in vitro replication of gastric digestions conditions (pH and lipase specificity) are demonstrated using examples from the most recent of studies. It is true that some animal models could be adapted to study infant lipid digestion physiology, however the ethical relevance of such models is questionable, hence the development of accurate in vitro models is a must. In vitro models that combine up to date knowledge of digestion biochemistry with intestinal cells in culture are the best choice to replicate digestion and absorption in infant population, this would allow the adaptation of infant formula for a better digestion and absorption of dietary lipids by preterm and term infants. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Semi-continuous anaerobic co-digestion of cow manure and steam-exploded Salix with recirculation of liquid digestate.

PubMed

Estevez, Maria M; Sapci, Zehra; Linjordet, Roar; Schnürer, Anna; Morken, John

2014-04-01

The effects of recirculating the liquid fraction of the digestate during mesophilic anaerobic co-digestion of steam-exploded Salix and cow manure were investigated in laboratory-scale continuously stirred tank reactors. An average organic loading rate of 2.6 g VS L(-1) d(-1) and a hydraulic retention time (HRT) of 30 days were employed. Co-digestion of Salix and manure gave better methane yields than digestion of manure alone. Also, a 16% increase in the methane yield was achieved when digestate was recirculated and used instead of water to dilute the feedstock (1:1 dilution ratio). The reactor in which the larger fraction of digestate was recirculated (1:3 dilution ratio) gave the highest methane yields. Ammonia and volatile fatty acids did not reach inhibitory levels, and some potentially inhibitory compounds released during steam explosion (i.e., furfural and 5-hydroxy methyl furfural) were only detected at trace levels throughout the entire study period. However, accumulation of solids, which was more pronounced in the recycling reactors, led to decreased methane yields in those systems after three HRTs. Refraining from the use of fresh water to dilute biomass with a high-solids content and obtaining a final digestate with increased dry matter content might offer important economic benefits in full-scale processes. To ensure long-term stability in such an approach, it would be necessary to optimize separation of the fraction of digestate to be recirculated and also perform proper monitoring to avoid accumulation of solids. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Effects of smoking on the thyroid gland, digestive system, kidney and bone].

PubMed

Underner, M; Hadjadj, S; Beauchant, M; Bridoux, F; Debiais, F; Meurice, J-C

2008-12-01

In addition to being a major cardiovascular risk factor, smoking promotes or worsens thyroid, digestive, renal and bone diseases. Smoking is positively associated with hyperthyroidism. It is associated with Graves' disease and it especially increases the risk of the development of severe exophthalmos. In contrast, smoking might exert a protective action for thyroid carcinoma. Smoking increases the severity of hepatic lesions in patients with chronic hepatitis C. Smoking accelerates the progression of primary biliary cirrhosis and increases the risk of hepatocellular carcinoma. Smoking increases risk of both hyperplastic and adenomatous polyps. While Crohn's disease is associated with smoking, ulcerative colitis is largely a disease of non smokers. Smoking increases risk of development of both renal cell carcinoma and chronic nephropathies, particularly in types 1 and 2 diabetes. Smoking is a risk factor for decreased bone density and is associated with a significantly increased risk of fracture. Smoking is related to the development of rheumatoid arthritis and may adversely influence its severity. Smoking might be considered a risk factor for the development of several thyroid, digestive, renal and bone diseases. Consequently, smoking prevention and cessation programs must be strongly encouraged among the patients concerned.

Anaerobic Digestion Alters Copper and Zinc Speciation.

PubMed

Legros, Samuel; Levard, Clément; Marcato-Romain, Claire-Emmanuelle; Guiresse, Maritxu; Doelsch, Emmanuel

2017-09-19

Anaerobic digestion is a widely used organic waste treatment process. However, little is known on how it could alter the speciation of contaminants in organic waste. This study was focused on determining the influence of anaerobic digestion on the speciation of copper and zinc, two metals that generally occur at high concentration in organic waste. Copper and zinc speciation was investigated by X-ray absorption spectroscopy in four different raw organic wastes (predigestion) and their digested counterparts (postdigestion, i.e., digestates). The results highlighted an increase in the digestates of the proportion of amorphous or nanostructured copper sulfides as well as amorphous or nanostructured zinc sulfides and zinc phosphate as compared to raw waste. We therefore suggest that the environmental fate of these elements would be different when spreading either digestates or raw waste on cropland.

Application of Methanobrevibacter acididurans in anaerobic digestion.

PubMed

Savant, D V; Ranade, D R

2004-01-01

To operate anaerobic digesters successfully under acidic conditions, hydrogen utilizing methanogens which can grow efficiently at low pH and tolerate high volatile fatty acids (VFA) are desirable. An acid tolerant hydrogenotrophic methanogen viz. Methanobrevibacter acididurans isolated from slurry of an anaerobic digester running on alcohol distillery wastewater has been described earlier by this lab. This organism could grow optimally at pH 6.0. In the experiments reported herein, M. acididurans showed better methanogenesis under acidic conditions with high VFA, particularly acetate, than Methanobacterium bryantii, a common hydrogenotrophic inhabitant of anaerobic digesters. Addition of M. acididurans culture to digesting slurry of acidogenic as well as methanogenic digesters running on distillery wastewater showed increase in methane production and decrease in accumulation of volatile fatty acids. The results proved the feasibility of application of M. acididurans in anaerobic digesters.

Fertilizer and sanitary quality of digestate biofertilizer from the co-digestion of food waste and human excreta.

PubMed

Owamah, H I; Dahunsi, S O; Oranusi, U S; Alfa, M I

2014-04-01

This research was aimed at assessing the fertilizer quality and public health implications of using digestate biofertilizer from the anaerobic digestion of food wastes and human excreta. Twelve (12) kg of food wastes and 3kg of human excreta were mixed with water in a 1:1 w/v to make 30-l slurry that was fed into the anaerobic digester to ferment for 60days at mesophilic temperature (22-31°C). Though BOD, COD, organic carbon and ash content in the feedstock were reduced after anaerobic digestion by 50.0%, 10.6%, 74.3% and 1.5% respectively, nitrogen, pH and total solids however increased by 12.1%, 42.5% and 12.4% respectively. The C/N ratios of the feedstock and compost are 135:1 and 15.8:1. The residual total coliforms of 2.10×10(8)CFU/100ml in the digestate was above tolerable limits for direct application on farmlands. Microbial analysis of the digestate biofertilizer revealed the presence of Pseudomonas, Klebsiella, Clostridium, Bacillus, Bacteroides, Penicillum, Salmollena, and Aspergillus. Klebsiella, Bacillus, Pseudomonas, Penicillum and Aspergillus can boost the efficiency of the biofertilizer through nitrogen fixation and nutrient solubility in soils but Klebsiella again and Salmollena are potential health risks to end users. Further treatment of the digestate for more efficient destruction of pathogens is advised. Copyright © 2014 Elsevier Ltd. All rights reserved.

Temperature-phased anaerobic digestion of food waste: A comparison with single-stage digestions based on performance and energy balance.

PubMed

Xiao, Benyi; Qin, Yu; Zhang, Wenzhe; Wu, Jing; Qiang, Hong; Liu, Junxin; Li, Yu-You

2018-02-01

The temperature-phased anaerobic digestion (TPAD) of food waste was studied for the purpose of comparing with single-stage mesophilic and thermophilic anaerobic digestion. The biogas and methane yields in the TPAD during the steady period were 0.759 ± 0.115 L/g added VS and 0.454 ± 0.201 L/g added VS, which were lower than those in the two single-stage anaerobic digestion. The improper sludge retention time may be the reason for the lower biogas and methane production in TPAD. The removal of volatile solids in the TPAD was 78.55 ± 4.59% and the lowest among the three anaerobic digestion processes. The reaction ratios of the four anaerobic digestion steps in the TPAD were all lower than those in the two single-stage anaerobic digestion. The energy conversion efficiency of the degraded substrate in the TPAD was similar with those in single-stage mesophilic and thermophilic anaerobic digestion systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Aquaporins in Digestive System.

PubMed

Zhu, Shuai; Ran, Jianhua; Yang, Baoxue; Mei, Zhechuan

2017-01-01

In this chapter, we mainly discuss the expression and function of aquaporins (AQPs ) expressed in digestive system . AQPs in gastrointestinal tract include four members of aquaporin subfamily: AQP1, AQP4, AQP5 and AQP8, and a member of aquaglyceroporin subfamily: AQP3. In the digestive glands, especially the liver, we discuss three members of aquaporin subfamily: AQP1, AQP5 and AQP8, a member of aquaglyceroporin subfamily: AQP9. AQP3 is involved in the diarrhea and inflammatory bowel disease; AQP5 is relevant to gastric carcinoma cell proliferation and migration; AQP9 plays considerable role in glycerol metabolism , urea transport and hepatocellular carcinoma. Further investigation is necessary for specific locations and functions of AQPs in digestive system.

Kenaf Bast Fibers—Part I: Hermetical Alkali Digestion

DOE PAGES

Shi, Jinshu; Shi, Sheldon Q.; Barnes, H. Michael; ...

2011-01-01

The objective of this study was to develop a hermetical alkali digestion process to obtain single cellulosic fibers from kenaf bast. Kenaf bast were hermetically digested into single fiber using a 5% sodium hydroxide solution for one hour at four different temperatures (80 ° C, 110 ° C, 130 ° C, and 160 ° C). The hermetical digestion process used in this study produced fibers with high cellulose content (84.2–92.3%) due to the removal of lignin and hemicelluloses. The surface hardness and elastic modulus of the fibers digested at 130 ° C and 160 ° C were improved significantly comparedmore » with those digested at 80 ° C. The tensile modulus and tensile strength of the individual fibers reduced as the digestion temperature increased from 110 ° C to 160 ° C. Micropores were generated in fiber cell wall when the fibers were digested at 130 ° C and 160 ° C. The studies on the composites that were made from polypropylene reinforced with the digested fibers indicated that the compatibility between the digested fibers and polypropylene matrix was poor.« less

Digestive cell turnover in digestive gland epithelium of slugs experimentally exposed to a mixture of cadmium and kerosene.

PubMed

Zaldibar, B; Cancio, I; Soto, M; Marigómez, I

2007-11-01

Slugs, Arion ater (L), have been proposed as sentinel organisms to assess soil health. In slugs under the influence of pollutants, digestive cell loss and the concomitant increase of excretory cells of the digestive gland have been described. The aim of the present work was to determine up to what extent digestive cell loss affects biomarkers and whether the affectation is reversible after exposure to a mixture of metal and organic pollutants. Slugs were dosed with a mixture of cadmium and kerosene in the food for 27 days. Apart from chemical analyses, the volume density of black silver deposits (Vv(BSD)) after autometallography, and acyl-CoA oxidase (AOX) activity were used as biomarkers of exposure to metals and organic compounds, respectively. As effect biomarkers, changes in the volume density of the cell types that constitute the digestive gland epithelium were calculated. Proliferating cells were identified by means of bromodeoxyuridine (BrdU) immunohistochemistry. Results revealed that the mixture of pollutants provoked an increase in Vv(BSD) and AOX activity and a decrease in the number of digestive cells. These changes had no effect in the digestive gland accumulation capacity or in the effect and exposure biomarkers employed. BrdU-labelling showed that exposure to pollutants provoked an enhanced digestive cell proliferation.

Problems of the Digestive System

MedlinePlus

... are examples of common digestive disorders? • What is irritable bowel syndrome? • What is celiac disease? • What is colorectal cancer? • ... Taking medications, especially antibiotics • Digestive diseases, such as irritable bowel syndrome What should I do if I have diarrhea? ...

The anaerobic digestion process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rivard, C.J.; Boone, D.R.

1996-01-01

The microbial process of converting organic matter into methane and carbon dioxide is so complex that anaerobic digesters have long been treated as {open_quotes}black boxes.{close_quotes} Research into this process during the past few decades has gradually unraveled this complexity, but many questions remain. The major biochemical reactions for forming methane by methanogens are largely understood, and evolutionary studies indicate that these microbes are as different from bacteria as they are from plants and animals. In anaerobic digesters, methanogens are at the terminus of a metabolic web, in which the reactions of myriads of other microbes produce a very limited rangemore » of compounds - mainly acetate, hydrogen, and formate - on which the methanogens grow and from which they form methane. {open_quotes}Interspecies hydrogen-transfer{close_quotes} and {open_quotes}interspecies formate-transfer{close_quotes} are major mechanisms by which methanogens obtain their substrates and by which volatile fatty acids are degraded. Present understanding of these reactions and other complex interactions among the bacteria involved in anaerobic digestion is only now to the point where anaerobic digesters need no longer be treated as black boxes.« less

Releasing N-glycan from peptide N-terminus by N-terminal succinylation assisted enzymatic deglycosylation.

PubMed

Weng, Yejing; Sui, Zhigang; Jiang, Hao; Shan, Yichu; Chen, Lingfan; Zhang, Shen; Zhang, Lihua; Zhang, Yukui

2015-04-22

Due to the important roles of N-glycoproteins in various biological processes, the global N-glycoproteome analysis has been paid much attention. However, by current strategies for N-glycoproteome profiling, peptides with glycosylated Asn at N-terminus (PGANs), generated by protease digestion, could hardly be identified, due to the poor deglycosylation capacity by enzymes. However, theoretically, PGANs occupy 10% of N-glycopeptides in the typical tryptic digests. Therefore, in this study, we developed a novel strategy to identify PGANs by releasing N-glycans through the N-terminal site-selective succinylation assisted enzymatic deglycosylation. The obtained PGANs information is beneficial to not only achieve the deep coverage analysis of glycoproteomes, but also discover the new biological functions of such modification.

Nanobiocatalysis for protein digestion in proteomic analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Jungbae; Kim, Byoung Chan; Lopez-Ferrer, Daniel

2010-02-01

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 onemore » 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.« less

A novel bioaugmentation strategy to accelerate methanogenesis via adding Geobacter sulfurreducens PCA in anaerobic digestion system.

PubMed

Zhang, Shuo; Chang, Jiali; Liu, Wei; Pan, Yiran; Cui, Kangping; Chen, Xi; Liang, Peng; Zhang, Xiaoyuan; Wu, Qing; Qiu, Yong; Huang, Xia

2018-06-12

Based on the new syntrophic methanogenesis route via direct interspecies electron transfer (DIET), a novel bioaugmentation method by adding exoelectrogenic Geobacter species to accelerate methanogenesis was developed in this study. Geobacter sulfurreducens PCA, type exoelectrogenic strain of Geobacter species was chosen for the research. To clarify the effect of G. sulfurreducens on methanogenesis, batch tests of CH 4 production were carried out. Acetate, the most typical precursor of methanogenesis was chosen as the substrate of batch tests. Amendment of G. sulfurreducens accelerated CH 4 production remarkably. The lag phase of CH 4 production was shortened, and the maximum CH 4 production rate was increased by 78%. Fluorescence in situ hybridization showed that G. sulfurreducens closely gathered with methanogens. For the archaeal communities, the high-throughput sequencing results demonstrated that Methanosaetaceae and Methanobacteriaceae were potential bioaugmented methanogens. We speculated that the accelerated methanogenesis by adding G. sulfurreducens may result from the syntrophic association between G. sulfurreducens and methanogens affiliated with Methanosaetaceae and Methanobacteriaceae. This research provides a new route to enhance methanogenesis through the utilization of G. sulfurreducens. Through this study, the role of Geobacter in the anaerobic engineering and carbon cycling of nature should be paid more attention. Copyright © 2018. Published by Elsevier B.V.

Testing low cost anaerobic digestion (AD) systems

USDA-ARS?s Scientific Manuscript database

To evaluate the potential for low technology and low cost digesters for small dairies, BARC and researchers from the University of Maryland installed six modified Taiwanese-model field-scale (FS) digesters near the original dairy manure digester. The FS units receive the same post-separated liquid ...

Interspecies conservation of retinal guanosine 5'-triphosphatase. Characterization by photoaffinity labelling and tryptic-peptide mapping.

PubMed Central

McMurray, M M; Hansen, J S; Haley, B E; Takemoto, D J; Takemoto, L J

1985-01-01

Light-activated hydrolysis of cyclic GMP is achieved through the photoexcitation of rhodopsin, a process which then triggers the replacement of GDP for GTP by a retinal guanosine 5'-triphosphatase referred to as 'transducin'. The transducin-GTP complex then switches on the phosphodiesterase [Fung, Hurley & Stryer (1981) Proc. Natl. Acad. Sci. U.S.A. 78, 152-156]. The bovine transducin consists of an alpha-subunit (39000 Mr), which is a GTP-binding component, together with a beta-(37000 Mr) and a gamma-subunit (10000 Mr). We have purified retinal transducin from cow, pig, chick and frog. The enzyme specific activities and sodium dodecyl sulphate/polyacrylamide-gel-electrophoretic profiles indicate that this enzyme is similar in all species except the frog. Whereas the bovine, pig and chick transducins consist of major 37000- and 39000-Mr components, that of the frog consists of a single 75000-Mr component. Labelling of the GTP-binding components with the photoaffinity label 8-azidoguanosine [gamma-32P]triphosphate demonstrated that the 37000-Mr components of the cow, pig and chick and the 75000-Mr component of the frog were major GTP-binding components. In addition, peptide maps of radioiodinated tryptic peptides indicate that the frog 75000-Mr protein is highly related to the pig transducin. These results demonstrate evolutionary conservation of retinal transducin and the presence of a higher-Mr, but nonetheless highly conserved form, of transducin in the frog. The relationship of this component to the recently reported rod-outer-segment inhibitor protein [Yamazaki, Stein, Chernoff & Bitensky (1983) J. Biol. Chem. 258, 8188-8194] is discussed. Images Fig. 2. Fig. 3. Fig. 4. Fig. 5. PMID:2983663

Optimizing the Logistics of Anaerobic Digestion of Manure

NASA Astrophysics Data System (ADS)

Ghafoori, Emad; Flynn, Peter C.

Electrical power production from the combustion of biogas from anaerobic digestion (AD) of manure is a means of recovering energy from animal waste. We evaluate the lowest cost method of moving material to and from centralized AD plants serving multiple confined feeding operations. Two areas are modeled, Lethbridge County, Alberta, Canada, an area of concentrated beef cattle feedlots, and Red Deer County, Alberta, a mixed-farming area with hog, dairy, chicken and beef cattle farms, and feedlots. We evaluate two types of AD plant: ones that return digestate to the source confined feeding operation for land spreading (current technology), and ones that process digestate to produce solid fertilizer and a dischargeable water stream (technology under development). We evaluate manure and digestate trucking, trucking of manure with return of digestate by pipelines, and pipelining of manure plus digestate. We compare the overall cost of power from these scenarios to farm or feedlot-based AD units. For a centralized AD plant with digestate return for land spreading the most economical transport option for manure plus digestate is by truck for the mixed-farming area and by pipelines for the concentrated feedlot area. For a centralized AD plant with digestate processing, the most economical transport option is trucking of manure for both cases.

Starch digestibility: past, present, and future.

PubMed

Bello-Perez, Luis A; Flores-Silva, Pamela C; Agama-Acevedo, Edith; Tovar, Juscelino

2018-02-10

In the last century, starch present in foods was considered to be completely digested. However, during the 1980s, studies on starch digestion started to show that besides digestible starch, which could be rapidly or slowly hydrolysed, there was a variable fraction that resisted hydrolysis by digestive enzymes. That fraction was named resistant starch (RS) and it encompasses those forms of starch that are not accessible to human digestive enzymes but can be fermented by the colonic microbiota, producing short-chain fatty acids. RS has been classified into five types, depending on the mechanism governing its resistance to enzymatic hydrolysis. Early research on RS was focused on the methods to determine its content in foods and its physiological effects, including fermentability in the large intestine. Later on, due to the interest of the food industry, methods to increase the RS content of isolated starches were developed. Nowadays, the influence of RS on the gut microbiota is a relevant research topic owing to its potential health-related benefits. This review summarizes over 30 years of investigation on starch digestibility, its relationship with human health, the methods to produce RS and its impact on the microbiome. © 2018 Society of Chemical Industry. © 2018 Society of Chemical Industry.

The microstructure of starchy food modulates its digestibility.

PubMed

Tian, Jinhu; Ogawa, Yukiharu; Shi, John; Chen, Shiguo; Zhang, Huiling; Liu, Donghong; Ye, Xingqian

2018-06-05

Starch is the main carbohydrate in human nutrition and shows a range of desired food properties. It has been demonstrated that fast digestion of starchy food can induce many health issues (e.g., hyperglycaemia, diabetes, etc.); therefore, how to modulate its digestion is an interesting topic. Previous studies have revealed that the microstructure and digestibility of starchy food of different botanical origin or from multiple processes are quite different; modulating starch digestion by retaining or altering its microstructure may be effective. In the present review, the current knowledge of the relationship between microstructural changes to starchy food and its digestibility at molecular, cell and tissue, and food processing levels is summarized. New technologies focused on microstructure studies and ways to manipulate food microstructure to modulate starch digestibility are also reviewed. In particular, some insights focusing on the future study of microstructure and the digestibility of starchy food are also suggested.

Cow, sheep and llama manure at psychrophilic anaerobic co-digestion with low cost tubular digesters in cold climate and high altitude.

PubMed

Martí-Herrero, J; Alvarez, R; Cespedes, R; Rojas, M R; Conde, V; Aliaga, L; Balboa, M; Danov, S

2015-04-01

The aim of this research is to evaluate the co-digestion of cow and llama manure combined with sheep manure, in psychrophilic conditions and real field low cost tubular digesters adapted to cold climate. Four digesters were monitored in cold climate conditions; one fed with cow manure, a second one with llama manure, the third one with co-digestion of cow-sheep manure and the fourth one was fed with llama-sheep manure. The slurry had a mean temperature of 16.6 °C, the organic load rate was 0.44 kgvs m(-3) d(-1) and the hydraulic retention time was 80 days. After one hundred days biogas production was stable, as was the methane content and the pH of the effluent. The co-digestion of cow-sheep manure results in a biogas production increase of 100% compared to the mono-digestion of cow manure, while co-digestion of llama-sheep manure results in a decrease of 50% in biogas production with respect to mono-digestion of llama manure. Copyright © 2015 Elsevier Ltd. All rights reserved.

[The digestive characteristics of fishes (the biocenotic aspects)].

PubMed

Kuz'mina, V V

1996-03-01

The cavity, membrane and intracellular digestion is added by two additional types of digestion in the fish: a symbiont digestion and an induced autolysis. As the intensity of processes maintained by the enzyme systems of the victim and a symbiont depends upon the structure and conditions of the biocenosis, the latter are regarded as an ecological component. The enzymes of microflora and objects of feeding contribute much to digestive processes in fish and take part in the adaptation of their digestive system to the character of the food and specifics of the biocenosis.

Secondary Structure and Subunit Composition of Soy Protein In Vitro Digested by Pepsin and Its Relation with Digestibility

PubMed Central

Yang, Yong; Wang, Zhongjiang; Wang, Rui; Sui, Xiaonan; Qi, Baokun; Han, Feifei; Li, Yang; Jiang, Lianzhou

2016-01-01

In the present study, in vitro digestibility and structure of soybean protein isolates (SPIs) prepared from five soybean varieties were investigated in simulated gastric fluid (SGF), using FT-IR microspectroscopy and SDS-PAGE. The result indicated that β-conformations were prone to be hydrolyzed by pepsin preferentially and transformed to unordered structure during in vitro digestion, followed by the digestion of α-helix and unordered structure. A negative linear correlation coefficient was found between the β-conformation contents of five SPIs and their in vitro digestibility values. The intensities of the protein bands corresponding to 7S and 11S fractions were decreased and many peptide bands appeared at 11~15 kDa during enzymatic hydrolysis. β-conglycinin was poorly hydrolyzed with pepsin, especially the β-7S subunit. On the other hand, basic polypeptides of glycinin degraded slower than acidic polypeptides and represented a large proportion of the residual protein after digestion. 11S-A3 of all SPIs disappeared after 1 h digestion. Moreover, a significant negative linear correlation coefficient (r = −0.89) was found between the β-7S contents of five SPIs and their in vitro digestibility values. These results are useful for further studies of the functional properties and bioactive properties of these varieties and laid theoretical foundations for the development of the specific functional soy protein isolate. PMID:27298825

Diagnosis of digestive functional disease by the statistics of continuous monitoring of esophageal acidity

NASA Astrophysics Data System (ADS)

Rivera Landa, Rogelio; Cardenas Cardenas, Eduardo; Fossion, Ruben; Pérez Zepeda, Mario Ulises

2014-11-01

Technological advances in the last few decennia allow the monitoring of many physiological observables in a continuous way, which in physics is called a "time series". The best studied physiological time series is that of the heart rhythm, which can be derived from an electrocardiogram (ECG). Studies have shown that a healthy heart is characterized by a complex time series and high heart rate variability (HRV). In adverse conditions, the cardiac time series degenerates towards randomness (as seen in, e.g., fibrillation) or rigidity (as seen in, e.g., ageing), both corresponding to a loss of HRV as described by, e.g., Golberger et. al [1]. Cardiac and digestive rhythms are regulated by the autonomous nervous system (ANS), that consists of two antagonistic branches, the orthosympathetic branch (ONS) that accelerates the cardiac rhythm but decelerates the digestive system, and the parasympathetic brand (PNS) that works in the opposite way. Because of this reason, one might expect that the statistics of gastro-esophageal time series, as described by Gardner et. al. [2,3], reflects the health state of the digestive system in a similar way as HRV in the cardiac case, described by Minocha et. al. In the present project, we apply statistical methods derived from HRV analysis to time series of esophageal acidity (24h pHmetry). The study is realized on data from a large patient population from the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán. Our focus is on patients with functional disease (symptoms but no anatomical damage). We find that traditional statistical approaches (e.g. Fourier spectral analysis) are unable to distinguish between different degenerations of the digestive system, such as gastric esophageal reflux disease (GERD) or functional gastrointestinal disorder (FGID).

O-linked oligosaccharides on insulin receptor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Collier, E.; Gorden, P.

1991-02-01

The insulin receptor, an integral membrane glycoprotein, is synthesized as a single-chain precursor that is cleaved to produce two mature subunits, both of which contain N-linked oligosaccharide chains and covalently linked fatty acids. We report that the beta-subunit also contains O-linked oligosaccharides. The proreceptor, alpha-subunit, and beta-subunit were labeled with (3H)mannose and (3H)galactose in the presence or absence of an inhibitor of O-linked glycosylation. Tryptic peptides from each component were separated by reverse-phase high-performance liquid chromatography. N- and O-linked oligosaccharide chains were identified on these peptides by specific enzymatic digestions. The proreceptor and alpha-subunit contained only N-linked oligosaccharides, whereas themore » beta-subunit contained both N- and O-linked oligosaccharides. The O-linked oligosaccharide chains were attached to a single tryptic fraction of the beta-subunit, which also contained N-linked chains. This fraction was further localized to the NH2-terminal tryptic peptide of the beta-subunit by specific immunoprecipitation with an anti-peptide antibody with specificity for this region. Binding of insulin and autophosphorylation of the beta-subunit were not dependent on O-linked glycosylation, because cells grown in the presence of the inhibitor exhibited a normal dose response to insulin. Therefore, the insulin receptor contains O-linked oligosaccharides on the NH2-terminal tryptic peptide of the beta-subunit, and these O-linked oligosaccharides are not necessary to the binding or autophosphorylation function of the receptor.« less

Effect of Different Heat Treatments on In Vitro Digestion of Egg White Proteins and Identification of Bioactive Peptides in Digested Products.

PubMed

Wang, Xuefen; Qiu, Ning; Liu, Yaping

2018-04-01

Chicken eggs are ingested by people after a series of processes, but to date, only a few studies have explored the nutrient variations caused by different heat treatments. In this work, the impacts of different heat treatments (4, 56, 65, and 100 °C on the in vitro digestibility of egg white proteins were investigated by hydrolysis with pepsin or pepsin + pancreatin to simulate human gastrointestinal digestion, and the digested products were identified using Nano-LC-ESI-MS/MS. Egg white proteins treated at 65 °C had the highest in vitro pepsin digestibility value whereas the pepsin + pancreatin digestibility increased significantly (P < 0.05) as the cooking temperature was raised. The molecular weight distribution of the digested products indicated that, when compared to pepsin-treated samples, pepsin + pancreatin-treated samples contained more low-molecular-weight peptides (m/z < 849.2) with higher signal intensities. The number of unique peptides identified in every digestion product showed a positive correlation with their in vitro digestibility. Additionally, bioactive peptides such as antioxidant, antimicrobial and antihypertensive peptides were found present in egg white digested products, especially in samples treated at 4 and 100 °C. These findings may facilitate a better understanding of nutritive values of egg white proteins and their digested products under different cooking temperatures, such as antibacterial and antioxidant peptides identified in the digestion samples treated, respectively at 4 and 100 °C. This study also provided information for improving the applications of eggs in the food industry as well as a theoretical basis for egg consumption. © 2018 Institute of Food Technologists®.

Photoenhanced anaerobic digestion of organic acids

DOEpatents

Weaver, Paul F.

1990-01-01

A process is described for rapid conversion of organic acids and alcohols anaerobic digesters into hydrogen and carbon dioxide, the optimal precursor substrates for production of methane. The process includes addition of photosynthetic bacteria to the digester and exposure of the bacteria to radiant energy (e.g., solar energy). The process also increases the pH stability of the digester to prevent failure of the digester. Preferred substrates for photosynthetic bacteria are the organic acid and alcohol waste products of fermentative bacteria. In mixed culture with methanogenic bacteria or in defined co-culture with non-aceticlastic methanogenic bacteria, photosynthetic bacteria are capable of facilitating the conversion or organic acids and alcohols into methane with low levels of light energy input.

Highly efficient peptide separations in proteomics. Part 2: bi- and multidimensional liquid-based separation techniques.

PubMed

Sandra, Koen; Moshir, Mahan; D'hondt, Filip; Tuytten, Robin; Verleysen, Katleen; Kas, Koen; François, Isabelle; Sandra, Pat

2009-04-15

Multidimensional liquid-based separation techniques are described for maximizing the resolution of the enormous number of peptides generated upon tryptic digestion of proteomes, and hence, reduce the spatial and temporal complexity of the sample to a level that allows successful mass spectrometric analysis. This review complements the previous contribution on unidimensional high performance liquid chromatography (HPLC). Both chromatography and electrophoresis will be discussed albeit with reversed-phase HPLC (RPLC) as the final separation dimension prior to MS analysis.

Physiology of digestion and the molecular characterization of the major digestive enzymes from Periplaneta americana.

PubMed

Tamaki, Fábio K; Pimentel, André C; Dias, Alcides B; Cardoso, Christiane; Ribeiro, Alberto F; Ferreira, Clélia; Terra, Walter R

2014-11-01

Cockroaches are among the first insects to appear in the fossil record. This work is part of ongoing research on insects at critical points in the evolutionary tree to disclose evolutionary trends in the digestive characteristics of insects. A transcriptome (454 Roche platform) of the midgut of Periplanetaamericana was searched for sequences of digestive enzymes. The selected sequences were manually curated. The complete or nearly complete sequences showing all characteristic motifs and highly expressed (reads counting) had their predicted sequences checked by cloning and Sanger sequencing. There are two chitinases (lacking mucin and chitin-binding domains), one amylase, two α- and three β-glucosidases, one β-galactosidase, two aminopeptidases (none of the N-group), one chymotrypsin, 5 trypsins, and none β-glucanase. Electrophoretic and enzymological data agreed with transcriptome data in showing that there is a single β-galactosidase, two α-glucosidases, one preferring as substrate maltase and the other aryl α-glucoside, and two β-glucosidases. Chromatographic and enzymological data identified 4 trypsins, one chymotrypsin (also found in the transcriptome), and one non-identified proteinase. The major digestive trypsin is identifiable to a major P. americana allergen (Per a 10). The lack of β-glucanase expression in midguts was confirmed, thus lending support to claims that those enzymes are salivary. A salivary amylase was molecularly cloned and shown to be different from the one from the midgut. Enzyme distribution showed that most digestion occurs under the action of salivary and midgut enzymes in the foregut and anterior midgut, except the posterior terminal digestion of proteins. A counter-flux of fluid may be functional in the midgut of the cockroach to explain the low excretory rate of digestive enzymes. Ultrastructural and immunocytochemical localization data showed that amylase and trypsin are released by both merocrine and apocrine secretion

Starch and fiber properties affect their kinetics of digestion and thereby digestive physiology in pigs.

PubMed

Zijlstra, R T; Jha, R; Woodward, A D; Fouhse, J; van Kempen, T A T G

2012-12-01

Traditionally in swine nutrition, analyses of starch and fiber have focused on assessing quantity; however, both have a wide range of functional properties making them underappreciated nutrients. Starch ranging from low to high amylose changes from rapidly digestible in the upper gut to poorly digestible but fermentable in the lower gut thereby changing from a source of glucose to VFA source. Likewise, fibers ranging from low to high viscosity affect digesta flow and from slowly to rapidly fermentable alter production of VFA serving as energy for the gut or whole body. Our hypothesis is that total extent, kinetics, and site of digestion or fermentation of starch and fiber are important for whole body nutrient use and intestinal health. To elucidate their effects, we developed in vitro, lab-based methodologies to describe kinetics of digestion and fermentation and linked these with in vivo models including i) ileum cannulation to collect digesta, ii) portal-vein catheterization to sequentially sample blood, iii) slaughter method to collect site-specific intestinal tissue and digesta, and iv) indirect calorimetry. Using these methods, kinetics of nutrient absorption was associated with pancreatic and intestinal hormones released into the portal vein, intestinal microbiota, and gene expression in intestinal tissue and microbiota. These studies confirmed that slowly digestible starch is partially degraded in the distal small and large intestine and fermented into VFA including butyrate (10-fold increase in net portal appearance), which reduces insulin responses by 60% and whole body energy use. Starch entering the distal intestine altered mRNA abundance of nutrient transporters and was bifidogenic. Extremely viscous purified fiber dampened glycemic responses and reduced digesta passage rate by 50% thereby increasing ileal digestion of dietary nutrients whereas increased fiber in feed grains reduced nutrient digestibility. Fermentable fiber increased butyrate and

Evaluating digestion efficiency in full-scale anaerobic digesters by identifying active microbial populations through the lens of microbial activity

NASA Astrophysics Data System (ADS)

Mei, Ran; Narihiro, Takashi; Nobu, Masaru K.; Kuroda, Kyohei; Liu, Wen-Tso

2016-09-01

Anaerobic digestion is a common technology to biologically stabilize wasted solids produced in municipal wastewater treatment. Its efficiency is usually evaluated by calculating the reduction in volatile solids, which assumes no biomass growth associated with digestion. To determine whether this assumption is valid and further evaluate digestion efficiency, this study sampled 35 digester sludge from different reactors at multiple time points together with the feed biomass in a full-scale water reclamation plant at Chicago, Illinois. The microbial communities were characterized using Illumina sequencing technology based on 16S rRNA and 16S rRNA gene (rDNA). 74 core microbial populations were identified and represented 58.7% of the entire digester community. Among them, active populations were first identified using the ratio of 16S rRNA and 16S rDNA (rRNA/rDNA) for individual populations, but this approach failed to generate consistent results. Subsequently, a recently proposed mass balance model was applied to calculate the specific growth rate (μ), and this approach successfully identified active microbial populations in digester (positive μ) that could play important roles than those with negative μ. It was further estimated that 82% of microbial populations in the feed sludge were digested in comparison with less than 50% calculated using current equations.

Apparent seed digestibility and germination of seeds after passage through the digestive system of northern bobwhite

USDA-ARS?s Scientific Manuscript database

Limited information is available regarding the digestibility or germination of seed after the passage through the digestive system of northern bobwhites (Colinus virginianus), especially of plants associated with the sand sagebrush (Artemisia filifolia)-mixed prairie community. Thus, our objectives...

Environmental diseases of the digestive system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rubin, E.; Farber, J.L.

1990-03-01

Environmental factors are important mediators of many diseases of the digestive system, defined as the alimentary tract and the accessory organs of digestion, the liver and pancreas. In this review, we principally focus on the action of chemical agents which are classified as (1) naturally occurring compounds, (2) occupational hazards, (3) therapeutic drugs, and (4) constituents of substances of abuse. In addition, the putative role of dietary habits in the pathogenesis of malignant diseases of the digestive system is discussed.54 references.

Evaluation of anaerobic digestion processes for short sludge-age waste activated sludge combined with anammox treatment of digestate liquor.

PubMed

Ge, Huoqing; Batstone, Damien; Keller, Jurg

2016-01-01

The need to reduce energy input and enhance energy recovery from wastewater is driving renewed interest in high-rate activated sludge treatment (i.e. short hydraulic and solids retention times (HRT and SRT, respectively)). This process generates short SRT activated sludge stream, which should be highly degradable. However, the evaluation of anaerobic digestion of short SRT sludge has been limited. This paper assesses anaerobic digestion of short SRT sludge digestion derived from meat processing wastewater under thermophilic and mesophilic conditions. The thermophilic digestion system (55°C) achieved 60 and 68% volatile solids destruction at 8 day and 10 day HRT, respectively, compared with 50% in the mesophilic digestion system (35°C, 10 day HRT). The digestion effluents from the thermophilic (8-10 day HRT) and mesophilic systems were stable, as assessed by residual methane potentials. The ammonia rich sludge dewatering liquor was effectively treated by a batch anammox process, which exhibited comparable nitrogen removal rate as the tests using a control synthetic ammonia solution, indicating that the dewatering liquor did not have inhibiting/toxic effects on the anammox activity.

Anaerobic digestion of selected Italian agricultural and industrial residues (grape seeds and leather dust): combined methane production and digestate characterization.

PubMed

Caramiello, C; Lancellotti, I; Righi, F; Tatàno, F; Taurino, R; Barbieri, L

2013-01-01

A combined experimental evaluation of methane production (obtained by anaerobic digestion) and detailed digestate characterization (with physical-chemical, thermo-gravimetric and mineralogical approaches) was conducted on two organic substrates, which are specific to Italy (at regional and national levels). One of the substrates was grape seeds, which have an agricultural origin, whereas the other substrate was vegetable-tanned leather dust, which has an industrial origin. Under the assumed experimental conditions of the performed lab-scale test series, the grape seed substrate exhibited a resulting net methane production of 175.0 NmL g volatile solids (VS)(-1); hence, it can be considered as a potential energy source via anaerobic digestion. Conversely, the net methane production obtained from the anaerobic digestion of the vegetable-tanned leather dust substrate was limited to 16.1 NmL gVS(-1). A detailed characterization of the obtained digestates showed that there were both nitrogen-containing compounds and complex organic compounds present in the digestate that was obtained from the mixture of leather dust and inoculum. As a general perspective of this experimental study, the application of diversified characterization analyzes could facilitate (1) a better understanding of the main properties of the obtained digestates to evaluate their potential valorization, and (2) a combination of the digestate characteristics with the corresponding methane productions to comprehensively evaluate the bioconversion process.

Enhancement of anaerobic digestion efficiency of wastewater sludge and olive waste: Synergistic effect of co-digestion and ultrasonic/microwave sludge pre-treatment.

PubMed

Alagöz, B Aylin; Yenigün, Orhan; Erdinçler, Ayşen

2015-12-01

This study investigates the effect of ultrasonic and microwave pre-treatment on biogas production from the anaerobic co-digestion of olive pomace and wastewater sludges. It was found that co-digestion of wastewater sludge with olive pomace yielded around 0.21 L CH4/g VS added, whereas the maximum methane yields from the mono-digestion of olive pomace and un-pretreated wastewater sludges were 0.18 and 0.16L CH4/g VS added. In the same way, compared to mono-digestion of these substrates, co-digestion increased methane production by 17-31%. The microwave and ultrasonic pre-treatments applied to sludge samples prior to co-digestion process led to further increase in the methane production by 52% and 24%, respectively, compared to co-digestion with un-pretreated wastewater sludge. The highest biogas and methane yields were obtained from the co-digestion of 30 min microwave pre-treated wastewater sludges and olive pomace to be 0.46 L/g VS added and 0.32 L CH4/g VS added, respectively. Copyright © 2015 Elsevier Ltd. All rights reserved.

Resistance of Soil-Bound Prions to Rumen Digestion

PubMed Central

Saunders, Samuel E.; Bartelt-Hunt, Shannon L.; Bartz, Jason C.

2012-01-01

Before prion uptake and infection can occur in the lower gastrointestinal system, ingested prions are subjected to anaerobic digestion in the rumen of cervids and bovids. The susceptibility of soil-bound prions to rumen digestion has not been evaluated previously. In this study, prions from infectious brain homogenates as well as prions bound to a range of soils and soil minerals were subjected to in vitro rumen digestion, and changes in PrP levels were measured via western blot. Binding to clay appeared to protect noninfectious hamster PrPc from complete digestion, while both unbound and soil-bound infectious PrPSc proved highly resistant to rumen digestion. In addition, no change in intracerebral incubation period was observed following active rumen digestion of unbound hamster HY TME prions and HY TME prions bound to a silty clay loam soil. These results demonstrate that both unbound and soil-bound prions readily survive rumen digestion without a reduction in infectivity, further supporting the potential for soil-mediated transmission of chronic wasting disease (CWD) and scrapie in the environment. PMID:22937149

[Anaerobic digestion of animal manure contaminated by tetracyclines].

PubMed

Tong, Zi-Lin; Liu, Yuan-Lu; Hu, Zhen-Hu; Yuan, Shou-Jun

2012-03-01

Anaerobic digestion of pig manure spiked with tetracycline (TC) and chlortetracycline (CTC) and the degradation of the two antibiotics during the anaerobic digestion at 35 degrees C were investigated. The results indicate that propionate was the main volatile fatty acid produced during the anaerobic digestion followed by acetate. Compared with the CTC addition, TC + CTC addition showed obvious inhibitory effect on the hydrolysis and acidification of easily digestible organic components of pig manure. The cumulative methane production of TC, CTC, TC + CTC and CK2 during anaerobic digestion was 386.4 mL, 406.0 mL, 412.1 mL and 464.6 mL, respectively. Degradation of TC and CTC followed the first-order kinetic equation. The half-life of TC and CTC was 14-18 days and 10 days, respectively. After the treatment of 45-day anaerobic digestion, the degradation efficiency of TC was 88.6%-91.6% with 97.7%-98.2% of CTC. Therefore, anaerobic digestion shows the benefit on the management of animal manures contaminated by tetracyclines.

Diurnal variation in ruminal pH on the digestibility of highly digestible perennial ryegrass during continuous culture fermentation.

PubMed

Wales, W J; Kolver, E S; Thorne, P L; Egan, A R

2004-06-01

Dairy cows grazing high-digestibility pastures exhibit pronounced diurnal variation in ruminal pH, with pH being below values considered optimal for digestion. Using a dual-flow continuous culture system, the hypothesis that minimizing diurnal variation in pH would improve digestion of pasture when pH was low, but not at a higher pH, was tested. Four treatments were imposed, with pH either allowed to exhibit normal diurnal variation around an average pH of 6.1 or 5.6, or maintained at constant pH. Digesta samples were collected during the last 3 d of each of four, 9-d experimental periods. A constant pH at 5.6 compared with a constant pH of 6.1 reduced the digestibility of organic matter (OM), neutral detergent (NDF), and acid detergent fiber (ADF) by 7, 14, and 21%, respectively. When pH was allowed to vary (averaging 5.6), digestion of OM, NDF, and ADF were reduced by 15,30, and 36%, respectively, compared with pH varying at 6.1. There was little difference in digestion parameters when pH was either constant or varied with an average pH of 6.1. However, when average pH was 5.6, maintaining a constant pH significantly increased digestion of OM, NDF, and ADF by 5, 25, and 24% compared with a pH that exhibited normal diurnal variation. These in vitro results show that gains in digestibility and potential milk production can be made by minimizing diurnal variation in ruminal pH, but only when ruminal pH is low (5.6). However, larger gains in productivity can be achieved by increasing average daily ruminal pH from 5.6 to 6.1.

Effect of biopolymer encapsulation on the digestibility of lipid and cholesterol oxidation products in beef during in vitro human digestion.

PubMed

Hur, Sun Jin; Lee, Seung Yuan; Lee, Seung-Jae

2015-01-01

In this study, beef patties were encapsulated with 3% chitosan, pectin, onion powder, or green tea powder and the beef patties were then passed through an in vitro human digestion model. The total lipid digestibility was lowest (p<0.05) in beef patties encapsulated with chitosan and pectin after digestion in the small intestine. Thiobarbituric acid reactive substance (TBARS) values were significantly lower (p<0.05) for beef patties encapsulated with chitosan and pectin, when compared with the control, after digestion in the small intestine. In contrast, the 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging activity was highest (p<0.05) in beef patties encapsulated with onion powder and green tea powder after digestion in the small intestine. The total cholesterol oxidation product (COP) content was significantly lower (p<0.05) in beef patties encapsulated with biopolymers than in the control after digestion in the small intestine. Copyright © 2014 Elsevier Ltd. All rights reserved.

Anaerobic co-digestion of dairy manure and potato waste

NASA Astrophysics Data System (ADS)

Yadanaparthi, Sai Krishna Reddy

Dairy and potato are two important agricultural commodities in Idaho. Both the dairy and potato processing industries produce a huge amount of waste which could cause environmental pollution. To minimize the impact of potential pollution associated with dairy manure (DM) and potato waste (PW), anaerobic co-digestion has been considered as one of the best treatment process. The purpose of this research is to evaluate the anaerobic co-digestion of dairy manure and potato waste in terms of process stability, biogas generation, construction and operating costs, and potential revenue. For this purpose, I conducted 1) a literature review, 2) a lab study on anaerobic co-digestion of dairy manure and potato waste at three different temperature ranges (ambient (20-25°C), mesophilic (35-37°C) and thermophilic (55-57°C) with five mixing ratios (DM:PW-100:0, 90:10, 80:20, 60:40, 40:60), and 3) a financial analysis for anaerobic digesters based on assumed different capital costs and the results from the lab co-digestion study. The literature review indicates that several types of organic waste were co-digested with DM. Dairy manure is a suitable base matter for the co-digestion process in terms of digestion process stability and methane (CH4) production (Chapter 2). The lab tests showed that co-digestion of DM with PW was better than digestion of DM alone in terms of biogas and CH4 productions (Chapter 3). The financial analysis reveals DM and PW can be used as substrate for full size anaerobic digesters to generate positive cash flow within a ten year time period. Based on this research, the following conclusions and recommendations were made: ▸ The ratio of DM:PW-80:20 is recommended at thermophilic temperatures and the ratio of DM:PW-90:10 was recommended at mesophilic temperatures for optimum biogas and CH4 productions. ▸ In cases of anaerobic digesters operated with electricity generation equipment (generators), low cost plug flow digesters (capital cost of 600/cow

Kinetics and advanced digester design for anaerobic digestion of water hyacinth and primary sludge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chynoweth, D.P.; Dolenc, D.A.; Ghosh, S.

1982-01-01

A research program centered around a facility located at Walt Disney World (WDW) is in progress to evaluate the use of water hyacinth (WH) for secondary and tertiary wastewater treatment, to optimize growth of WH under these conditions, and to convert the resultant primary sludge (PS) and WH to methane via anaerobic digestion. This article describes the status of the biogasification component of this program, which includes baseline and advanced digestion experiments with individual feeds and blends and the design of an experimental test unit (ETU) to be installed at WDW. Experiments with several blends demonstrated that methane yields canmore » be predicted from the fractional content and methane yield of each component. The process was found to adhere to the Monod kinetic model for microbial growth, and associated kinetic parameters were developed for various feed combinations. A novel upflow digester is achieving significantly higher conversion than a stirred-tank digester. Of several pretreatment techniques used, only alkaline treatment resulted in increased biodegradability. A larger scale (4.5 m/sup 3/) experimental test unit is being designed for installation at WDW in 1982. 13 figures, 4 tables.« less

Zero-valent iron enhanced methanogenic activity in anaerobic digestion of waste activated sludge after heat and alkali pretreatment.

PubMed

Zhang, Yaobin; Feng, Yinghong; Quan, Xie

2015-04-01

Heat or alkali pretreatment is the effective method to improve hydrolysis of waste sludge and then enhance anaerobic sludge digestion. However the pretreatment may inactivate the methanogens in the sludge. In the present work, zero-valent iron (ZVI) was used to enhance the methanogenic activity in anaerobic sludge digester under two methanogens-suppressing conditions, i.e. heat-pretreatment and alkali condition respectively. With the addition of ZVI, the lag time of methane production was shortened, and the methane yield increased by 91.5% compared to the control group. The consumption of VFA was accelerated by ZVI, especially for acetate, indicating that the acetoclastic methanogenesis was enhanced. In the alkali-condition experiment, the hydrogen produced decreased from 27.6 to 18.8 mL when increasing the ZVI dosage from 0 to 10 g/L. Correspondingly, the methane yield increased from 1.9 to 32.2 mL, which meant that the H2-utilizing methanogenes was enriched. These results suggested that the addition of ZVI into anaerobic digestion of sludge after pretreated by the heat or alkali process could efficiently recover the methanogenic activity and increase the methane production and sludge reduction. Copyright © 2015 Elsevier Ltd. All rights reserved.

Children and Grief. ERIC Digest.

ERIC Educational Resources Information Center

McEntire, Nancy

Noting that the death of a loved one brings grief to children as well as adults, this Digest draws on research to examine how children respond to death and the role of parents and teachers in helping children cope with loss. The Digest delineates children's "tasks" during mourning that are essential to their adjustment to loss, such as…

Environmental assessment of digestate treatment technologies using LCA methodology.

PubMed

Vázquez-Rowe, Ian; Golkowska, Katarzyna; Lebuf, Viooltje; Vaneeckhaute, Céline; Michels, Evi; Meers, Erik; Benetto, Enrico; Koster, Daniel

2015-09-01

The production of biogas from energy crops, organic waste and manure has augmented considerably the amounts of digestate available in Flanders. This has pushed authorities to steadily introduce legislative changes to promote its use as a fertilising agent. There is limited arable land in Flanders, which entails that digestate has to compete with animal manure to be spread. This forces many anaerobic digestion plants to further treat digestate in such a way that it can either be exported or the nitrogen be removed. Nevertheless, the environmental impact of these treatment options is still widely unknown, as well as the influence of these impacts on the sustainability of Flemish anaerobic digestion plants in comparison to other regions where spreading of raw digestate is allowed. Despite important economic aspects that must be considered, the use of Life Cycle Assessment (LCA) is suggested in this study to identify the environmental impacts of spreading digestate directly as compared to four different treatment technologies. Results suggest relevant environmental gains when the digestate mix is treated using the examined conversion technologies prior to spreading, although important trade-offs between impact categories were observed and discussed. The promising results of digestate conversion technologies suggest that further LCA analyses should be performed to delve into, for instance, the appropriateness to shift to nutrient recovery technologies rather than digestate conversion treatments. Copyright © 2015 Elsevier Ltd. All rights reserved.

The identification of disulfides in ricin D using proteolytic cleavage followed by negative-ion nano-electrospray ionization mass spectrometry of the peptide fragments.

PubMed

Tran, T T Nha; Brinkworth, Craig S; Bowie, John H

2015-01-30

To use negative-ion nano-electrospray ionization mass spectrometry of peptides from the tryptic digest of ricin D, to provide sequence information; in particular, to identify disulfide position and connectivity. Negative-ion fragmentations of peptides from the tryptic digest of ricin D was studied using a Waters QTOF2 mass spectrometer operating in MS and MS(2) modes. Twenty-three peptides were obtained following high-performance liquid chromatography and studied by negative-ion mass spectrometry covering 73% of the amino-acid residues of ricin D. Five disulfide-containing peptides were identified, three intermolecular and two intramolecular disulfide-containing peptides. The [M-H](-) anions of the intermolecular disulfides undergo facile cleavage of the disulfide units to produce fragment peptides. In negative-ion collision-induced dissociation (CID) these source-formed anions undergo backbone cleavages, which provide sequencing information. The two intramolecular disulfides were converted proteolytically into intermolecular disulfides, which were identified as outlined above. The positions of the five disulfide groups in ricin D may be determined by characteristic negative-ion cleavage of the disulfide groups, while sequence information may be determined using the standard negative-ion backbone cleavages of the resulting cleaved peptides. Negative-ion mass spectrometry can also be used to provide partial sequencing information for other peptides (i.e. those not containing Cys) using the standard negative-ion backbone cleavages of these peptides. Copyright © 2014 John Wiley & Sons, Ltd.

Subnanogram proteomics: Impact of LC column selection, MS instrumentation and data analysis strategy on proteome coverage for trace samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, Ying; Zhao, Rui; Piehowski, Paul D.

One of the greatest challenges for mass spectrometry (MS)-based proteomics is the limited ability to analyze small samples. Here we investigate the relative contributions of liquid chromatography (LC), MS instrumentation and data analysis methods with the aim of improving proteome coverage for sample sizes ranging from 0.5 ng to 50 ng. We show that the LC separations utilizing 30-µm-i.d. columns increase signal intensity by >3-fold relative to those using 75-µm-i.d. columns, leading to 32% increase in peptide identifications. The Orbitrap Fusion Lumos mass spectrometer significantly boosted both sensitivity and sequencing speed relative to earlier generation Orbitraps (e.g., LTQ-Orbitrap), leading tomore » a ~3× increase in peptide identifications and 1.7× increase in identified protein groups for 2 ng tryptic digests of bacterial lysate. The Match Between Runs algorithm of open-source MaxQuant software further increased proteome coverage by ~ 95% for 0.5 ng samples and by ~42% for 2 ng samples. The present platform is capable of identifying >3000 protein groups from tryptic digestion of cell lysates equivalent to 50 HeLa cells and 100 THP-1 cells (~10 ng total proteins), respectively, and >950 proteins from subnanogram bacterial and archaeal cell lysates. The present ultrasensitive LC-MS platform is expected to enable deep proteome coverage for subnanogram samples, including single mammalian cells.« less

Hemicellulose conversion by anaerobic digestion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, S.; Henry, M.P.; Christopher, R.W.

1982-01-01

The digestibility of an aquatic biomass (water hyacinth), a land-based biomass (Coastal Bermuda grass), and a biomass-waste blend (a mixture of hyacinth, grass, MSW, and sludge) under various digestion conditions was studied. Anaerobic digestion of hemicellulose consists of the steps of enzymatic hydrolysis of hemicellulose to glucans, mannans, galactans, xylans, and arabans, and then to simple hexose and pentose sugars; production of C/sub 2/ and higher fatty acids from the simple sugars; conversion of higher fatty acids to acetate; and finally, production of methane and CO/sub 2/ from acetate, and CO/sub 2/ and hydrogen. The conversion of hemicellulose was highermore » under mesophilic conditions than those of cellulose or protein for all biomass test feeds, probably because the hemicellulose structure was more vulnerable to enzymatic attack than that of the lignocellulosic component. Cellulose conversion efficiencies at the mesophilic and thermophilic temperatures were about the same. However, hemicellulose was converted at a much lower efficiency than cellulose during thermophilic digestion - a situation that was the reverse of that observed at the mesophilic temperature. Cellulose was utilized in preference to hemicellulose during mesophilic digestion of nitrogen-supplemented Bermuda grass. It was speculated that Bermuda grass cellulose was converted at a higher efficiency than hemicellulose in the presence of external nitrogen because the metabolism of the breakdown product (glucose) of cellulose requires the least investment of enzymes and energy.« less

Anaerobic digestion foaming causes--a review.

PubMed

Ganidi, Nafsika; Tyrrel, Sean; Cartmell, Elise

2009-12-01

Anaerobic digestion foaming has been encountered in several sewage treatment plants in the UK. Foaming has raised major concerns for the water companies due to significant impacts on process efficiency and operational costs. Several foaming causes have been identified over the past few years by researchers. However, the supporting experimental information is limited and in some cases absent. The present report aims to provide a detailed review of the current anaerobic digestion foaming problem and to identify gaps in knowledge regarding the theory of foam formation in anaerobic digesters.

Fungal fermentation on anaerobic digestate for lipid-based biofuel production.

PubMed

Zhong, Yuan; Liu, Zhiguo; Isaguirre, Christine; Liu, Yan; Liao, Wei

2016-01-01

Anaerobic digestate is the effluent from anaerobic digestion of organic wastes. It contains a significant amount of nutrients and lignocellulosic materials, even though anaerobic digestion consumed a large portion of organic matters in the wastes. Utilizing the nutrients and lignocellulosic materials in the digestate is critical to significantly improve efficiency of anaerobic digestion technology and generate value-added chemical and fuel products from the organic wastes. Therefore, this study focused on developing an integrated process that uses biogas energy to power fungal fermentation and converts remaining carbon sources, nutrients, and water in the digestate into biofuel precursor-lipid. The process contains two unit operations of anaerobic digestion and digestate utilization. The digestate utilization includes alkali treatment of the mixture feed of solid and liquid digestates, enzymatic hydrolysis for mono-sugar release, overliming detoxification, and fungal fermentation for lipid accumulation. The experimental results conclude that 5 h and 30 °C were the preferred conditions for the overliming detoxification regarding lipid accumulation of the following fungal cultivation. The repeated-batch fungal fermentation enhanced lipid accumulation, which led to a final lipid concentration of 3.16 g/L on the digestate with 10% dry matter. The mass and energy balance analysis further indicates that the digestate had enough water for the process uses and the biogas energy was able to balance the needs of individual unit operations. A fresh-water-free and energy-positive process of lipid production from anaerobic digestate was achieved by integrating anaerobic digestion and fungal fermentation. The integration addresses the issues that both biofuel industry and waste management encounter-high water and energy demand of biofuel precursor production and few digestate utilization approaches of organic waste treatment.

A meta-analysis of feed digestion in dairy cows. 1. The effects of forage and concentrate factors on total diet digestibility.

PubMed

Nousiainen, J; Rinne, M; Huhtanen, P

2009-10-01

A meta-analysis based on published experiments with lactating dairy cows was conducted to study the effects of dietary forage and concentrate factors on apparent total diet digestibility. A data set was collected that included a total of 497 dietary treatment means from 92 studies. The diets were based on grass silage or on legume or whole-crop cereal silages partly or completely substituted for grass silage. The silages were supplemented with concentrates given at a flat rate within a dietary comparison. For the statistical evaluation, the data were divided into 5 subsets to quantify silage (digestibility, 42 diets in 17 studies; fermentation characteristics, 108 diets in 39 studies) and concentrate (amount of supplementation, 142 diets in 59 studies; concentration of crude protein, 215 diets in 82 studies; carbohydrate composition, 66 diets in 23 studies) factors on total diet digestibility. The diet digestibility of dairy cows was determined by total fecal collection or by using acid-insoluble ash as an internal marker. Diet organic matter digestibility (OMD) at a maintenance level of feeding (OMD(m)) was estimated using sheep in vivo or corresponding in vitro digestibility values for the forage and reported ingredient and chemical composition values, with tabulated digestibility coefficients for the concentrate components of the diet. A mixed model regression analysis was used to detect the responses of different dietary factors on apparent total diet digestibility. Improved silage OMD(m) resulting from earlier harvest was translated into improved production-level OMD in cows (OMD(p)). The effects of silage fermentation characteristics on OMD(p) were quantitatively small, although sometimes significant. Concentrate supplementation improved total diet OMD(m), but this was not realized in lactating dairy cows because of linearly decreased neutral detergent fiber (NDF) digestibility as concentrate intake increased. Increasing the concentrate crude protein amount

Association of dipeptidyl peptidase 4 inhibitors with risk of metastases in patients with type 2 diabetes and breast, prostate or digestive system cancer.

PubMed

Rathmann, Wolfgang; Kostev, Karel

2017-04-01

Experimental and animal studies have supported the hypothesis that dipeptidyl peptidase-4 inhibitors (DPP-4i) may accelerate tumor metastasis. The aim was to analyze the relationships between DPP-4i therapy with risk of metastases in type 2 diabetes patients with breast, prostate and digestive organ cancers. Type 2 diabetes patients with first diagnoses of breast, prostate or digestive organ cancer were selected in general and internal medicine practices (Disease Analyzer Germany: 01/2008-12/2014). Propensity score matching between DPP-4i users and non-users was carried out for age, sex, diabetes duration, and metformin use. Time-dependent Cox regression models were used to estimate hazard ratios (HR) for metastases further adjusting for HbA1c, body mass index, comorbidity and co-therapy with glucose-lowering drugs (3-4years follow-up). 668 patients with newly diagnosed breast cancer, 906 with prostate cancer and 908 with digestive organ cancer were analyzed. In Cox regression, use of DPP-4i was not associated with an increased risk of metastases in patients with breast (adjusted HR, 95%CI: 1.00, 0.49-2.02), prostate (0.98, 0.54-1.77) or digestive organ cancers (0.97, 0.57-1.66). This first observational study in patients with type 2 diabetes and breast, prostate or digestive organ cancer found no increased risk of metastases in DPP-4i users. Copyright © 2017 Elsevier Inc. All rights reserved.

Composition and Digestibility of Deer Browse in Southern Forests

Treesearch

Henry L. Short; Robert M. Blair; E.A. Epps

1975-01-01

Twigs were most nutritious and digestible during early growth in spring; they were high in fiber content and low in digestibility during summer, autumn, and winter. Evergreen leaves did not vary substantially in nutrient content and digestibility throughout the year. By contrast, leaves of deciduous species were reduced in quality and digestibility after leaf-fall....

Discourses of Disability in the "Digest."

ERIC Educational Resources Information Center

Barton, Ellen

2001-01-01

Presents an account of the discourse of disability in the "Reader's Digest" during its first 30 years (1922-1952). Concludes that the construction of disability in the "Digest" raises important questions that should enter the field of disability studies. (PM)

Microalgal Cultivation in Treating Liquid Digestate from Biogas Systems.

PubMed

Xia, Ao; Murphy, Jerry D

2016-04-01

Biogas production via anaerobic digestion (AD) has rapidly developed in recent years. In addition to biogas, digestate is an important byproduct. Liquid digestate is the major fraction of digestate and may contain high levels of ammonia nitrogen. Traditional processing technologies (such as land application) require significant energy inputs and raise environmental risks (such as eutrophication). Alternatively, microalgae can efficiently remove the nutrients from digestate while producing high-value biomass that can be used for the production of biochemicals and biofuels. Both inorganic and organic carbon sources derived from biogas production can significantly improve microalgal production. Land requirement for microalgal cultivation is estimated as 3% of traditional direct land application of digestate. Copyright © 2015 Elsevier Ltd. All rights reserved.

The functional-morphological adaptive strategy of digestive organs of decapodiform cephalopods

PubMed Central

OMURA, Ayano; ENDO, Hideki

2015-01-01

The digestive organs in decapodiform cephalopod species morphologically vary by individual lifestyle. We examined the following six species of adult decapodiformes cephalopods representing different habitats: Todarodes pacificus, Loligo bleekeri, Loligo edulis, Watasenia scintillans (pelagic), Sepia lycidas and Euprymna morsei (benthic). L. bleekeri and L. edulis possess a bursiform cecal sac connected to the cecum. Pelagic species have a single digestive gland smaller than in benthic species. T. pacificus has an oval digestive gland larger than that of L. bleekeri and L. edulis, which possess withered-looking and smaller digestive glands. In contrast, the digestive glands in benthic species are paired. S. lycidas and E. morsei have well-developed and larger digestive glands than those of the pelagic species. Well-developed digestive duct appendages are found in benthic species. In qualification of the mass of digestive organs, pelagic species have smaller stomachs, digestive glands and digestive ducts’ appendages than benthic species. Because pelagic species need to swim, they may possess smaller stomachs and larger cecums for more rapid digestion. A smaller digestive gland may have the advantage of reducing the body weight in pelagic species for rapid swimming. In contrast, since benthic species require a longer time for digestion than pelagic species, they compact more food in their stomachs and absorb nutrients via more organs, such as the digestive grand and digestive duct appendages, in addition to cecum. PMID:26369293

The functional-morphological adaptive strategy of digestive organs of decapodiform cephalopods.

PubMed

Omura, Ayano; Endo, Hideki

2016-01-01

The digestive organs in decapodiform cephalopod species morphologically vary by individual lifestyle. We examined the following six species of adult decapodiformes cephalopods representing different habitats: Todarodes pacificus, Loligo bleekeri, Loligo edulis, Watasenia scintillans (pelagic), Sepia lycidas and Euprymna morsei (benthic). L. bleekeri and L. edulis possess a bursiform cecal sac connected to the cecum. Pelagic species have a single digestive gland smaller than in benthic species. T. pacificus has an oval digestive gland larger than that of L. bleekeri and L. edulis, which possess withered-looking and smaller digestive glands. In contrast, the digestive glands in benthic species are paired. S. lycidas and E. morsei have well-developed and larger digestive glands than those of the pelagic species. Well-developed digestive duct appendages are found in benthic species. In qualification of the mass of digestive organs, pelagic species have smaller stomachs, digestive glands and digestive ducts' appendages than benthic species. Because pelagic species need to swim, they may possess smaller stomachs and larger cecums for more rapid digestion. A smaller digestive gland may have the advantage of reducing the body weight in pelagic species for rapid swimming. In contrast, since benthic species require a longer time for digestion than pelagic species, they compact more food in their stomachs and absorb nutrients via more organs, such as the digestive grand and digestive duct appendages, in addition to cecum.

In vitro digestibility of individual amino acids in rumen-undegraded protein: the modified three-step procedure and the immobilized digestive enzyme assay.

PubMed

Boucher, S E; Calsamiglia, S; Parsons, C M; Stern, M D; Moreno, M Ruiz; Vázquez-Añón, M; Schwab, C G

2009-08-01

Three soybean meal, 3 SoyPlus (West Central Cooperative, Ralston, IA), 5 distillers dried grains with solubles, and 5 fish meal samples were used to evaluate the modified 3-step in vitro procedure (TSP) and the in vitro immobilized digestive enzyme assay (IDEA; Novus International Inc., St. Louis, MO) for estimating digestibility of AA in rumen-undegraded protein (RUP-AA). In a previous experiment, each sample was ruminally incubated in situ for 16 h, and in vivo digestibility of AA in the intact samples and in the rumen-undegraded residues (RUR) was obtained for all samples using the precision-fed cecectomized rooster assay. For the modified TSP, 5 g of RUR was weighed into polyester bags, which were then heat-sealed and placed into Daisy(II) incubator bottles. Samples were incubated in a pepsin/HCl solution followed by incubation in a pancreatin solution. After this incubation, residues remaining in the bags were analyzed for AA, and digestibility of RUP-AA was calculated based on disappearance from the bags. In vitro RUP-AA digestibility estimates obtained with this procedure were highly correlated to in vivo estimates. Corresponding intact feeds were also analyzed via the pepsin/pancreatin steps of the modified TSP. In vitro estimates of AA digestibility of the feeds were highly correlated to in vivo RUP-AA digestibility, which suggests that the feeds may not need to be ruminally incubated before determining RUP-AA digestibility in vitro. The RUR were also analyzed via the IDEA kits. The IDEA values of the RUR were good predictors of RUP-AA digestibility in soybean meal, SoyPlus, and distillers dried grains with solubles, but the IDEA values were not as good predictors of RUP-AA digestibility in fish meal. However, the IDEA values of intact feed samples were also determined and were highly correlated to in vivo RUP-AA digestibility for all feed types, suggesting that the IDEA value of intact feeds may be a better predictor of RUP-AA digestibility than the IDEA

The fate of b-ions in the two worlds of collision-induced dissociation.

PubMed

Waldera-Lupa, Daniel M; Stefanski, Anja; Meyer, Helmut E; Stühler, Kai

2013-12-01

Fragment analysis of proteins and peptides by mass spectrometry using collision-induced dissociation (CID) revealed that the pairwise generated N-terminal b- and C-terminal y-ions have different stabilities resulting in underrepresentation of b-ions. Detailed analyses of large-scale spectra databases and synthetic peptides underlined these observations and additionally showed that the fragmentation pattern depends on utilized CID regime. To investigate this underrepresentation further we systematically compared resonant excitation energy and beam-type CID facilitated on different mass spectrometer platforms: (i) quadrupole time-of-flight, (ii) linear ion trap and (iii) three-dimensional ion trap. Detailed analysis of MS/MS data from a standard tryptic protein digest revealed that b-ions are significantly underrepresented on all investigated mass spectrometers. By N-terminal acetylation of tryptic peptides we show for the first time that b-ion cyclization reaction significantly contributes to b-ion underrepresentation even on ion trap instruments and accounts for at most 16% of b-ion loss. © 2013.

Solvent-free MALDI-MS for the analysis of a membrane protein via the mini ball mill approach: case study of bacteriorhodopsin.

PubMed

Trimpin, Sarah; Deinzer, Max L

2007-01-01

A mini ball mill (MBM) solvent-free matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) method allows for the analysis of bacteriorhodopsin (BR), an integral membrane protein that previously presented special analytical problems. For well-defined signals in the molecular ion region of the analytes, a desalting procedure of the MBM sample directly on the MALDI target plate was used to reduce adduction by sodium and other cations that are normally attendant with hydrophobic peptides and proteins as a result of the sample preparation procedure. Mass analysis of the intact hydrophobic protein and the few hydrophobic and hydrophilic tryptic peptides available in the digest is demonstrated with this robust new approach. MS and MS/MS spectra of BR tryptic peptides and intact protein were generally superior to the traditional solvent-based method using the desalted "dry" MALDI preparation procedure. The solvent-free method expands the range of peptides that can be effectively analyzed by MALDI-MS to those that are hydrophobic and solubility-limited.

Detecting molecular forms of antithrombin by LC-MRM-MS: defining the measurands.

PubMed

Ruhaak, L Renee; Romijn, Fred P H T M; Smit, Nico P M; van der Laarse, Arnoud; Pieterse, Mervin M; de Maat, Moniek P M; Haas, Fred J L M; Kluft, Cornelis; Amiral, Jean; Meijer, Piet; Cobbaert, Christa M

2018-05-01

Antithrombin (AT) is a critical regulator of coagulation, and its overall activity is typically measured using functional tests. A large number of molecular forms of AT have been identified and each individual carries multiple molecular proteoforms representing variable activities. Conventional functional tests are completely blind for these proteoforms. A method that ensures properly defined measurands for AT is therefore needed. We here assess whether mass spectrometry technology, in particular multiple reaction monitoring (MRM), is suitable for the quantification of AT and the qualitative detection of its molecular proteoforms. Plasma proteins were denatured, reduced and alkylated prior to enzymatic digestion. MRM transitions were developed towards tryptic peptides and glycopeptides using AT purified from human plasma. For each peptide, three transitions were measured, and stable isotope-labeled peptides were used for quantitation. Completeness of digestion was assessed using digestion time curves. MRM transitions were developed for 19 tryptic peptides and 4 glycopeptides. Two peptides, FDTISEK and FATTFYQHLADSK, were used for quantitation, and using a calibration curve of isolated AT in 40 g/L human serum albumin, CVs below 3.5% were obtained for FDTISEK, whereas CVs below 8% were obtained for FATTFYQHLADSK. Of the 26 important AT mutations, 20 can be identified using this method, while altered glycosylation profiles can also be detected. We here show the feasibility of the liquid chromatography multiple reaction monitoring mass spectrometry (LC-MRM-MS) technique for the quantitation of AT and the qualitative analysis of most of its molecular proteoforms. Knowing the measurands will enable standardization of AT tests by providing in-depth information on the molecular proteoforms of AT.

Digestive morphophysiology of Gryllodes sigillatus (Orthoptera: Gryllidae).

PubMed

Biagio, Fernanda P; Tamaki, Fabio K; Terra, Walter R; Ribeiro, Alberto F

2009-12-01

The evolution of the digestive system in the Order Orthoptera is disclosed from the study of the morphophysiology of the digestive process in its major taxa. This paper deals with a cricket representing the less known suborder Ensifera. Most amylase and trypsin activities occur in crop and caeca, respectively. Maltase and aminopeptidase are found in soluble and membrane-bound forms in caeca, with aminopeptidase also occurring in ventriculus. Amaranth was orally fed to Gryllodes sigillatus adults or injected into their haemolymph. The experiments were performed with starving and feeding insects with identical results. Following feeding of the dye the luminal side of the most anterior ventriculus (and in lesser amounts the midgut caeca) became heavily stained. In injected insects, the haemal side of the most posterior ventriculus was stained. This suggested that the anterior ventriculus is the main site of water absorption (the caeca is a secondary one), whereas the posterior ventriculus secretes water into the gut. Thus, a putative counter-current flux of fluid from posterior to anterior ventriculus may propel digestive enzyme recycling. This was confirmed by the finding that digestive enzymes are excreted at a low rate. The fine structure of midgut caeca and ventriculus cells revealed that they have morphological features that may be related to their involvement in secretion (movement from cell to lumen) and absorption (movement from lumen to cell) of fluids. Furthermore, morphological data showed that both merocrine and apocrine secretory mechanisms occur in midgut cells. The results showed that cricket digestion differs from that in grasshopper in having: (1) more membrane-bound digestive enzymes; (2) protein digestion slightly displaced toward the ventriculus; (3) midgut fluxes, and hence digestive enzyme recycling, in both starved and fed insects.

Over 4,100 protein identifications from a Xenopus laevis fertilized egg digest using reversed-phase chromatographic prefractionation followed by capillary zone electrophoresis - electrospray ionization - tandem mass spectrometry analysis

PubMed Central

Yan, Xiaojing; Sun, Liangliang; Zhu, Guijie; Cox, Olivia F.; Dovichi, Norman J.

2016-01-01

A tryptic digest generated from Xenopus laevis fertilized embryos was fractionated by reversed phase liquid chromatography. One set of 30 fractions was analyzed by 100-min CZE-ESI-MS/MS separations (50 hr total instrument time), and a second set of 15 fractions was analyzed by 3-hr UPLC-ESI-MS/MS separations (45 hr total instrument time). CZE-MS/MS produced 70% as many protein IDs (4,134 vs. 5,787) and 60% as many peptide IDs (22,535 vs. 36,848) as UPLC-MS/MS with similar instrument time (50 h vs. 45 h) but with 50 times smaller total consumed sample amount (1.5 μg vs. 75 μg). Surprisingly, CZE generated peaks that were 25% more intense than UPLC for peptides that were identified by both techniques, despite the 50-fold lower loading amount; this high sensitivity reflects the efficient ionization produced by the electrokinetically-pumped nanospray interface used in CZE. This report is the first comparison of CZE-MS/MS and UPLC-MS/MS for large-scale eukaryotic proteomic analysis. The numbers of protein and peptide identifications produced by CZE-ESI-MS/MS approach those produced by UPLC-MS/MS, but with nearly two orders of magnitude lower sample amounts. PMID:27723263

Anaerobic digestion and co-digestion of slaughterhouse waste (SHW): influence of heat and pressure pre-treatment in biogas yield.

PubMed

Cuetos, M J; Gómez, X; Otero, M; Morán, A

2010-10-01

Mesophilic anaerobic digestion (34+/-1 degrees C) of pre-treated (for 20 min at 133 degrees C, >3 bar) slaughterhouse waste and its co-digestion with the organic fraction of municipal solid waste (OFMSW) have been assessed. Semi-continuously-fed digesters worked with a hydraulic retention time (HRT) of 36 d and organic loading rates (OLR) of 1.2 and 2.6 kg VS(feed)/m(3)d for digestion and co-digestion, respectively, with a previous acclimatization period in all cases. It was not possible to carry out an efficient treatment of hygienized waste, even less so when OFMSW was added as co-substrate. These digesters presented volatile fatty acids (VFA), long chain fatty acids (LCFA) and fats accumulation, leading to instability and inhibition of the degradation process. The aim of applying a heat and pressure pre-treatment to promote splitting of complex lipids and nitrogen-rich waste into simpler and more biodegradable constituents and to enhance biogas production was not successful. These results indicate that the temperature and the high pressure of the pre-treatment applied favoured the formation of compounds that are refractory to anaerobic digestion. The pre-treated slaughterhouse wastes and the final products of these systems were analyzed by FTIR and TGA. These tools verified the existence of complex nitrogen-containing polymers in the final effluents, confirming the formation of refractory compounds during pre-treatment. (c) 2010 Elsevier Ltd. All rights reserved.

Acceleration modules in linear induction accelerators

NASA Astrophysics Data System (ADS)

Wang, Shao-Heng; Deng, Jian-Jun

2014-05-01

The Linear Induction Accelerator (LIA) is a unique type of accelerator that is capable of accelerating kilo-Ampere charged particle current to tens of MeV energy. The present development of LIA in MHz bursting mode and the successful application into a synchrotron have broadened LIA's usage scope. Although the transformer model is widely used to explain the acceleration mechanism of LIAs, it is not appropriate to consider the induction electric field as the field which accelerates charged particles for many modern LIAs. We have examined the transition of the magnetic cores' functions during the LIA acceleration modules' evolution, distinguished transformer type and transmission line type LIA acceleration modules, and re-considered several related issues based on transmission line type LIA acceleration module. This clarified understanding should help in the further development and design of LIA acceleration modules.

Experimental digester facility modifications and digester gas upgrading research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Srivastava, V.J.; Biljetina, R.; Akin, C.

1989-01-01

The Institute of Gas Technology (IGT) has been participating in an experimental program at the Community Waste Research Facility (CWRF) located at the Walt Disney World Resort Complex, Orlando, Florida. Four institutions have formed a team to provide solutions to community waste treatment and disposal programs. Of primary importance to this research effort is the implementation of low-cost, energy-efficient waste treatment and recovery technologies and the net production of energy (methane) from biomass and waste resources. The production of methane is being studied in a novel, high-rate digester. During 1988, we were responsible for modifying the Experimental Test Unit (ETU)more » to permit dry solids feeding of refuse-derived fuel (RDF) and for conducting bench-scale experiments to evaluate techniques for efficient removal of carbon dioxide produced during anaerobic digestion.« less

HOXC9-Induced Differentiation in Neuroblastoma Development

DTIC Science & Technology

2013-10-01

and should not be construed as an official Department of the Army position, policy or decision unless so designated by other documentation...C. The digests were desalted with a Micro Trap desalting cartridge (Michrom BioResources), and tryptic peptides eluted with LC-MS Solvent B (90/10...and H.-F.D. designed the study with the assistance of H.S., J.C., and S.H. H.-F.D. wrote the manuscript with contributions from J.D., J.-H.C., L.C.N

- Invited Review - Calcium Digestibility and Metabolism in Pigs*

PubMed Central

González-Vega, J. C.; Stein, H. H.

2014-01-01

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

Digestive Physiological Characteristics of the Gobiidae

PubMed Central

Hur, Sang-Woo; Kim, Shin-Kwon; Kim, Dae-Jung; Lee, Bae-Ik; Park, Su-Jin; Hwang, Hyung-Gyu; Jun, Je-Cheon; Myeong, Jeong-In; Lee, Chi-Hoon; Lee, Young-Don

2016-01-01

In this study, we investigated the characteristics of CCK-producing cells and mucus-secreting goblet cells with respect to stomach fish and stomachless fish of the Gobiidae in order to provide a basis for understanding the digestive physiology. Hairychin goby (Sagamia geneionema), which is stomachless fish, the numbers of mucus-secreting goblet cells is highest in the posterior intestine portion (P<0.05), while CCK-producing cells are scattered throughout the intestine. Gluttonous goby (Chasmichthys gulosus), which is stomach fish, mucus-secreting goblet cells are most abundant in the mid intestine portion (P<0.05), whereas CCK-producing cells are observed only in the anterior and mid intestine portion. Trident goby (Tridentiger obscurus) which is stomach fish, mucus-secreting goblet cells were most abundant in the mid intestine portion (P<0.05). CCK-producing cells are found in the anterior and mid intestine portion. Giurine goby, Rhinogobius giurinus which is also stomach fish, the largest number of mucus-secreting goblet cells showed in anterior intestine portion except for esophagus (P<0.05). CCK-producing cells are present only in the anterior and mid intestine portion. In S. geneionema, digestive action occurs in the posterior intestine portion to protect and functions to activate digestion. In contrast, in C. gulosus, T. obscurus and R. giurinus, their digestive action occurs in the anterior and mid intestine portion to protect and functions to activate digestion. Further studies of the modes of food ingestion by these fish, the contents of their digestive tracts, and the staining characteristics of the goblet cells need to be carried out. PMID:27796002

Micro-quantity tissue digestion for metal measurements by use of a microwave acid-digestion bomb.

PubMed

Nicholson, J R; Savory, M G; Savory, J; Wills, M R

1989-03-01

We describe a simple and convenient method for processing small amounts of tissue samples for trace-metal measurements by atomic absorption spectrometry, by use of a modified Parr microwave digestion bomb. Digestion proceeds rapidly (less than or equal to 90 s) in a sealed Teflon-lined vessel that eliminates contamination or loss from volatilization. Small quantities of tissue (5-100 mg dry weight) are digested in high-purity nitric acid, yielding concentrations of analyte that can be measured directly without further sample manipulation. We analyzed National Institute of Standards and Technology bovine liver Standard Reference Material to verify the accuracy of the technique. We assessed the applicability of the technique to analysis for aluminum in bone by comparison with a dry ashing procedure.

Quantitative measurement of protein digestion in simulated gastric fluid.

PubMed

Herman, Rod A; Korjagin, Valerie A; Schafer, Barry W

2005-04-01

The digestibility of novel proteins in simulated gastric fluid is considered to be an indicator of reduced risk of allergenic potential in food, and estimates of digestibility for transgenic proteins expressed in crops are required for making a human-health risk assessment by regulatory authorities. The estimation of first-order rate constants for digestion under conditions of low substrate concentration was explored for two protein substrates (azocoll and DQ-ovalbumin). Data conformed to first-order kinetics, and half-lives were relatively insensitive to significant variations in both substrate and pepsin concentration when high purity pepsin preparations were used. Estimation of digestion efficiency using densitometric measurements of relative protein concentration based on SDS-PAGE corroborated digestion estimates based on measurements of dye or fluorescence release from the labeled substrates. The suitability of first-order rate constants for estimating the efficiency of the pepsin digestion of novel proteins is discussed. Results further support a kinetic approach as appropriate for comparing the digestibility of proteins in simulated gastric fluid.

Comparison of start-up strategies and process performance during semi-continuous anaerobic digestion of sugarcane filter cake co-digested with bagasse.

PubMed

Janke, Leandro; Leite, Athaydes F; Nikolausz, Marcell; Radetski, Claudemir M; Nelles, Michael; Stinner, Walter

2016-02-01

The anaerobic digestion of sugarcane filter cake and the option of co-digestion with bagasse were investigated in a semi-continuous feeding regime to assess the main parameters used for large-scale process designing. Moreover, fresh cattle manure was considered as alternative inoculum for the start-up of biogas reactors in cases where digestate from a biogas plant would not be available in remote rural areas. Experiments were carried out in 6 lab-scale semi-continuous stirred-tank reactors at mesophilic conditions (38±1°C) while the main anaerobic digestion process parameters monitored. Fresh cattle manure demonstrated to be appropriate for the start-up process. However, an acclimation period was required due to the high initial volatile fatty acids concentration (8.5gL(-1)). Regardless the mono-digestion of filter cake presented 50% higher biogas yield (480mLgVS(-1)) than co-digestion with bagasse (320mLgVS(-1)) during steady state conditions. A large-scale co-digestion system would produce 58% more biogas (1008m(3)h(-1)) than mono-digestion of filter cake (634m(3)h(-1)) due to its higher biomass availability for biogas conversion. Considering that the biogas production rate was the technical parameter that displayed the most relevant differences between the analyzed substrate options (0.99-1.45m(3)biogasm(3)d(-1)). The decision of which substrate option should be implemented in practice would be mainly driven by the available construction techniques, since economically efficient tanks could compensate the lower biogas production rate of co-digestion option. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effects of digestion temperature and temperature shock on the biogas yields from the mesophilic anaerobic digestion of swine manure.

PubMed

Chae, K J; Jang, Am; Yim, S K; Kim, In S

2008-01-01

In order to obtain basic design criteria for anaerobic digesters of swine manure, the effects of different digesting temperatures, temperature shocks and feed loads, on the biogas yields and methane content were evaluated. The digester temperatures were set at 25, 30 and 35 degrees C, with four feed loads of 5%, 10%, 20% and 40% (feed volume/digester volume). At a temperature of 30 degrees C, the methane yield was reduced by only 3% compared to 35 degrees C, while a 17.4% reduction was observed when the digestion was performed at 25 degrees C. Ultimate methane yields of 327, 389 and 403 mL CH(4)/g VS(added) were obtained at 25, 30 and 35 degrees C, respectively; with moderate feed loads from 5% to 20% (V/V). From the elemental analysis of swine manure, the theoretical biogas and methane yields at standard temperature and pressure were 1.12L biogas/g VS(destroyed) and 0.724 L CH(4)/g VS(destroyed), respectively. Also, the methane content increased with increasing digestion temperatures, but only to a small degree. Temperature shocks from 35 to 30 degrees C and again from 30 to 32 degrees C led to a decrease in the biogas production rate, but it rapidly resumed the value of the control reactor. In addition, no lasting damage was observed for the digestion performance, once it had recovered.

Modified anaerobic digestion elutriated phased treatment for the anaerobic co-digestion of sewage sludge and food wastewater.

PubMed

Mo, Kyung; Lee, Wonbae; Kim, Moonil

2017-02-01

A modified anaerobic digestion elutriated phased treatment (MADEPT) process was developed for investigating anaerobic co-digestion of sewage sludge and food wastewater. The anaerobic digestion elutriated phased treatment (ADEPT) process is similar to a two-phase system, however, in which the effluent from a methanogenic reactor recycles into an acidogenic reactor to elutriate mainly dissolved organics. Although ADEPT could reduce reactor volume significantly, the unsolubilized solids should be wasted from the system. The MADEPT process combines thermo-alkali solubilization with ADEPT to improve anaerobic performance and to minimize the sludge disposal. It was determined that the optimal volume mixing ratio of sewage sludge and food wastewater was 4 : 1 for the anaerobic co-digestion. The removal efficiencies of total chemical oxygen demand, volatile solids, and volatile suspended solids in the MADEPT process were 73%, 70%, and 64%, respectively. However, those in the ADEPT process were only 48%, 37%, and 40%, respectively, at the same hydraulic retention time (HRT) of 7 days. The gas production of MADEPT was two times higher than that of ADEPT. The thermo-alkali solubilization increased the concentration of dissolved organics so that they could be effectively degraded in a short HRT, implying that MADEPT could improve the performance of ADEPT in anaerobic co-digestion.

Student Teachers' Ways of Thinking and Ways of Understanding Digestion and the Digestive System in Biology

ERIC Educational Resources Information Center

Çimer, Sabiha Odabasi; Ursavas, Nazihan

2012-01-01

The purpose of this study was to identify the ways in which student teachers understand digestion and the digestive system and, subsequently, their ways of thinking, as reflected in their problem solving approaches and the justification schemes that they used to validate their claims. For this purpose, clinical interviews were conducted with 10…

Formation of reactive aldehydes (MDA, HHE, HNE) during the digestion of cod liver oil: comparison of human and porcine in vitro digestion models.

PubMed

Tullberg, Cecilia; Larsson, Karin; Carlsson, Nils-Gunnar; Comi, Irene; Scheers, Nathalie; Vegarud, Gerd; Undeland, Ingrid

2016-03-01

In this work, we investigated lipid oxidation of cod liver oil during gastrointestinal (GI) digestion using two types of in vitro digestion models. In the first type of model, we used human GI juices, while we used digestive enzymes and bile from porcine origin in the second type of model. Human and porcine models were matched with respect to factors important for lipolysis, using a standardized digestion protocol. The digests were analysed for reactive oxidation products: malondialdehyde (MDA), 4-hydroxy-trans-2-nonenal (HNE), and 4-hydroxy-trans-2-hexenal (HHE) by liquid chromatography/atmospheric pressure chemical ionization-mass spectrometry (LC/APCI-MS), and for free fatty acids (FFA) obtained during the digestion by gas chromatography-mass spectrometry (GC-MS). The formation of the oxidation products MDA, HHE, and HNE was low during the gastric digestion, however, it increased during the duodenal digestion. The formation of the oxidation products reached higher levels when digestive juices of human origin were used (60 μM of MDA, 0.96 μM of HHE, and 1.6 μM of HNE) compared to when using enzymes and bile of porcine origin (9.8, and 0.36 μM of MDA; 0.16, and 0.026 μM of HHE; 0.23, and 0.005 μM of HNE, respectively, in porcine models I and II). In all models, FFA release was only detected during the intestinal step, and reached up to 31% of total fatty acids (FA). The findings in this work may be of importance when designing oxidation oriented lipid digestion studies.

Sequence of the radioactive tryptic peptide obtained after inactivating the F1-ATPase of the thermophilic bacterium PS3 with 5'-p-fluorosulfonylbenzoyl(3H)adenosine at 65 degrees C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bullough, D.A.; Yoshida, M.; Allison, W.S.

1986-02-01

Following a lag of about 30 min, the F1-ATPase from the thermophilic bacterium, PS3 (TF1), was inactivated slowly by 0.8 mM 5'-p-fluorosulfonylbenzoyladenosine (FSBA) at 23 degrees C and pH 7.0. When the enzyme was treated with 0.2 mM FSBA at pH 7.0 and 23 degrees C for 15 min and gel-filtered, no enzyme activity was lost. However, the lag in inactivation was abolished when the enzyme was subsequently incubated with 2.0 mM FSBA at 23 degrees C in the pH range from 6.8 to 10.0. The pH-inactivation profile obtained under these conditions revealed a pK alpha of about 9.3 whichmore » was associated with the inactivation. When pretreated TF1 was inactivated at 23 degrees C with (3H)FSBA by about 90%, greater than 20 mol of (3H)SBA was incorporated per mole of enzyme. TF1 was inactivated rapidly by 0.8 mM FSBA at pH 6.4 and 65 degrees C, and no lag was observed. Following inactivation of TF1 with 0.8 mM (3H)FSBA at 65 degrees C and pH 6.4, about 10 mol of (3H)SBA was incorporated per mole of enzyme. When a tryptic digest of the labeled enzyme was fractionated by reversed-phase high-performance liquid chromatography, a single major radioactive peptide was isolated. When subjected to automatic Edman degradation, this peptide was shown to have the amino acid sequence: A-L-A-P-E-I-V-G-E-E-H-X-Q-V-A-R, where X indicates that a phenylthiohydantoin derivative was not detected in cycle 12. However, from the DNA sequence of the gene encoding the subunit of TF1 (Y. Kagawa, M. Ishizuka, T. Saishu, and S. Nakao (1985)), this position has been shown to be occupied by tyrosine. This tyrosine is homologous with beta-Tyr-368 of the bovine mitochondrial F1-ATPase (MF1) the modification of which is responsible for the inactivation MF1 by FSBA.« less

Biochemical, Transcriptomic and Proteomic Analyses of Digestion in the Scorpion Tityus serrulatus: Insights into Function and Evolution of Digestion in an Ancient Arthropod

PubMed Central

Fuzita, Felipe J.; Pinkse, Martijn W. H.; Patane, José S. L.; Juliano, Maria A.; Verhaert, Peter D. E. M.; Lopes, Adriana R.

2015-01-01

Scorpions are among the oldest terrestrial arthropods and they have passed through small morphological changes during their evolutionary history on land. They are efficient predators capable of capturing and consuming large preys and due to envenomation these animals can become a human health challenge. Understanding the physiology of scorpions can not only lead to evolutionary insights but also is a crucial step in the development of control strategies. However, the digestive process in scorpions has been scarcely studied. In this work, we describe the combinatory use of next generation sequencing, proteomic analysis and biochemical assays in order to investigate the digestive process in the yellow scorpion Tityus serrulatus, mainly focusing in the initial protein digestion. The transcriptome generated database allowed the quantitative identification by mass spectrometry of different enzymes and proteins involved in digestion. All the results suggested that cysteine cathepsins play an important role in protein digestion. Two digestive cysteine cathepsins were isolated and characterized presenting acidic characteristics (pH optima and stability), zymogen conversion to the mature form after acidic activation and a cross-class inhibition by pepstatin. A more elucidative picture of the molecular mechanism of digestion in a scorpion was proposed based on our results from Tityus serrulatus. The midgut and midgut glands (MMG) are composed by secretory and digestive cells. In fasting animals, the secretory granules are ready for the next predation event, containing enzymes needed for alkaline extra-oral digestion which will compose the digestive fluid, such as trypsins, astacins and chitinase. The digestive vacuoles are filled with an acidic proteolytic cocktail to the intracellular digestion composed by cathepsins L, B, F, D and legumain. Other proteins as lipases, carbohydrases, ctenitoxins and a chitolectin with a perithrophin domain were also detected. Evolutionarily

Biochemical, transcriptomic and proteomic analyses of digestion in the scorpion Tityus serrulatus: insights into function and evolution of digestion in an ancient arthropod.

PubMed

Fuzita, Felipe J; Pinkse, Martijn W H; Patane, José S L; Juliano, Maria A; Verhaert, Peter D E M; Lopes, Adriana R

2015-01-01

Scorpions are among the oldest terrestrial arthropods and they have passed through small morphological changes during their evolutionary history on land. They are efficient predators capable of capturing and consuming large preys and due to envenomation these animals can become a human health challenge. Understanding the physiology of scorpions can not only lead to evolutionary insights but also is a crucial step in the development of control strategies. However, the digestive process in scorpions has been scarcely studied. In this work, we describe the combinatory use of next generation sequencing, proteomic analysis and biochemical assays in order to investigate the digestive process in the yellow scorpion Tityus serrulatus, mainly focusing in the initial protein digestion. The transcriptome generated database allowed the quantitative identification by mass spectrometry of different enzymes and proteins involved in digestion. All the results suggested that cysteine cathepsins play an important role in protein digestion. Two digestive cysteine cathepsins were isolated and characterized presenting acidic characteristics (pH optima and stability), zymogen conversion to the mature form after acidic activation and a cross-class inhibition by pepstatin. A more elucidative picture of the molecular mechanism of digestion in a scorpion was proposed based on our results from Tityus serrulatus. The midgut and midgut glands (MMG) are composed by secretory and digestive cells. In fasting animals, the secretory granules are ready for the next predation event, containing enzymes needed for alkaline extra-oral digestion which will compose the digestive fluid, such as trypsins, astacins and chitinase. The digestive vacuoles are filled with an acidic proteolytic cocktail to the intracellular digestion composed by cathepsins L, B, F, D and legumain. Other proteins as lipases, carbohydrases, ctenitoxins and a chitolectin with a perithrophin domain were also detected. Evolutionarily

Purification and sequencing of the active site tryptic peptide from penicillin-binding protein 1b of Escherichia coli

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicholas, R.A.; Suzuki, H.; Hirota, Y.

This paper reports the sequence of the active site peptide of penicillin-binding protein 1b from Escherichia coli. Purified penicillin-binding protein 1b was labeled with (/sup 14/C)penicillin G, digested with trypsin, and partially purified by gel filtration. Upon further purification by high-pressure liquid chromatography, two radioactive peaks were observed, and the major peak, representing over 75% of the applied radioactivity, was submitted to amino acid analysis and sequencing. The sequence Ser-Ile-Gly-Ser-Leu-Ala-Lys was obtained. The active site nucleophile was identified by digesting the purified peptide with aminopeptidase M and separating the radioactive products on high-pressure liquid chromatography. Amino acid analysis confirmed thatmore » the serine residue in the middle of the sequence was covalently bonded to the (/sup 14/C)penicilloyl moiety. A comparison of this sequence to active site sequences of other penicillin-binding proteins and beta-lactamases is presented.« less

The protein composition of the digestive fluid from the venus flytrap sheds light on prey digestion mechanisms.

PubMed

Schulze, Waltraud X; Sanggaard, Kristian W; Kreuzer, Ines; Knudsen, Anders D; Bemm, Felix; Thøgersen, Ida B; Bräutigam, Andrea; Thomsen, Line R; Schliesky, Simon; Dyrlund, Thomas F; Escalante-Perez, Maria; Becker, Dirk; Schultz, Jörg; Karring, Henrik; Weber, Andreas; Højrup, Peter; Hedrich, Rainer; Enghild, Jan J

2012-11-01

The Venus flytrap (Dionaea muscipula) is one of the most well-known carnivorous plants because of its unique ability to capture small animals, usually insects or spiders, through a unique snap-trapping mechanism. The animals are subsequently killed and digested so that the plants can assimilate nutrients, as they grow in mineral-deficient soils. We deep sequenced the cDNA from Dionaea traps to obtain transcript libraries, which were used in the mass spectrometry-based identification of the proteins secreted during digestion. The identified proteins consisted of peroxidases, nucleases, phosphatases, phospholipases, a glucanase, chitinases, and proteolytic enzymes, including four cysteine proteases, two aspartic proteases, and a serine carboxypeptidase. The majority of the most abundant proteins were categorized as pathogenesis-related proteins, suggesting that the plant's digestive system evolved from defense-related processes. This in-depth characterization of a highly specialized secreted fluid from a carnivorous plant provides new information about the plant's prey digestion mechanism and the evolutionary processes driving its defense pathways and nutrient acquisition.

Effect of Recycle Sludge on Anaerobic Digestion of Palm Oil Mill Effluent in A Thermophilic Continuous Digester

NASA Astrophysics Data System (ADS)

Irvan; Trisakti, B.; Tomiuchi, Y.; Harahap, U.; Daimon, H.

2017-06-01

The objective of this research is to maintain short retention time and high degradation of palm oil mill effluent (POME) to biogas by applying recycle sludge. Fresh POME from Rambutan Mill without further treatment was used as feed. Two lab-scale digesters supported from Metawater Co. Ltd. have been applied to treat POME at thermophilic (55°C) condition. Both digesters were operated under intermittent operation mode. Experiments were performed in two methods: with and without recycle sludge. Hydraulic retention time (HRT) of both methods was maintained at 6 days, while sludge retention time (SRT) was maintained at various days. The result showed that by extending SRT in return sludge process where 25% of digested slurry recycled to the digester, improvement of volatile solid (VS) decomposition was obtained around 84% at HRT of 6 days and SRT of 21 days. Then, chemical oxygen demand (COD) removal efficiency could be reached until 85% by using recycle sludge.

[Current concepts of digestion and absorption of carbohydrates].

PubMed

Luz, S dos S; de Campos, P L; Ribeiro, S M; Tirapegui, J

1997-01-01

The aim of this paper is to review recent aspects of digestion and absorption of carbohydrates that are the main source of energy in human diets. Recent researches have found that starch is not largely hydrolysed and absorbed in the small bowel but one part of it is resistant to digestion. Several food factors may be responsible for digestion and absorption velocity and totality of carbohydrates. Therefore, carbohydrate classification must be based not only on molecular size to express the real carbohydrates utilization as an energy source by humans. In agreement with molecular size of carbohydrate, its classification can be: a) monosaccharides; b) disaccharides; c) oligosaccharides; d) polysaccharides. In agreement with carbohydrate digestibility or availability, its classification can be: a) digestible carbohydrates; b) undigestable carbohydrates (NSP). Carbohydrate digestibility can be altered by several factors like: Intrinsic factors: a) physical structure; b) molecular physical distribution; c) physical state of food; d) food antinutrients. Extrinsics factors: a) chewing; b) transit time of food; c) amount of starch present; d) diet antinutrients. Under influence of this factors, process of digestion happen by enzymatic activity a long the gastrointestinal tract. Salivary and pancreatic amylase; glycosidases of the duodenal enterocyte brush border (lactase, sacarase and maltase), whose activity happen by close interaction of digestive breakdown with transport. The summarized pathways of the absorptive process: 1. movement from the bulk phase of the lumenal or mucosal fluid to enterocyte surface; 2. movement across the brush border membrane through specific transporters: a) SGLT1; b) GLUT 5; c) passive diffusion. 3. movement across the basolateral membrane by the GLUT 2.

In vitro digestibility of goat milk and kefir with a new standardised static digestion method (INFOGEST cost action) and bioactivities of the resultant peptides.

PubMed

Nehir El, Sedef; Karakaya, Sibel; Simsek, Sebnem; Dupont, Didier; Menfaatli, Esra; Eker, Alper Tolga

2015-07-01

The hydrolysis degrees of goat milk and kefir during simulated gastrointestinal digestion and some bioactivities of the resulting peptides after fermentation and digestion were studied. A static in vitro digestion method by the COST FA1005 Action INFOGEST was used and goat milk and kefir were partially hydrolyzed during the gastric phase and had above 80% hydrolysis after duodenal digestion. There were no differences between the digestibility of goat milk and kefir (p > 0.05). Goat milk and kefir displayed about 7-fold antioxidant activity after digestion (p < 0.05). Fermentation showed no effect on the calcium-binding capacity of the samples (p > 0.05), however, after in vitro digestion calcium-binding capacity of the goat milk and kefir increased 2 and 5 fold, respectively (p < 0.05). Digested goat milk and kefir showed a higher dose-dependent inhibitory effect on α-amylase compared to undigested samples (p < 0.05). α-Glucosidase inhibitory activities and in vitro bile acid-binding capacities of the samples were not determined at the studied concentrations.

Improved design of anaerobic digesters for household biogas production in indonesia: one cow, one digester, and one hour of cooking per day.

PubMed

Usack, Joseph G; Wiratni, Wiratni; Angenent, Largus T

2014-01-01

A government-sponsored initiative in Indonesia to design and implement low-cost anaerobic digestion systems resulted in 21 full-scale systems with the aim to satisfy the cooking fuel demands of rural households owning at least one cow. The full-scale design consisted of a 0.3 m diameter PVC pipe, which was operated as a conventional plug-flow system. The system generated enough methane to power a cooking stove for ∼ 1 h. However, eventual clogging from solids accumulation inside the bioreactor proved to be a major drawback. Here, we improved the digester configuration to remedy clogging while maintaining system performance. Controlled experiments were performed using four 9-L laboratory-scale digesters operated at a temperature of 27 ± 1 °C, a volatile solids loading rate of 2.0 g VS · L(-1) · day(-1), and a 21-day hydraulic retention time. Two of the digesters were replicates of the original design (control digesters), while the other two digesters included internal mixing or effluent recycle (experimental digesters). The performance of each digester was compared based on methane yields, VS removal efficiencies, and steady-state solids concentrations during an operating period of 311 days. Statistical analyses revealed that internal mixing and effluent recycling resulted in reduced solids accumulation compared to the controls without diminishing methane yields or solids removal efficiencies.

Improved Design of Anaerobic Digesters for Household Biogas Production in Indonesia: One Cow, One Digester, and One Hour of Cooking per Day

PubMed Central

Usack, Joseph G.; Wiratni, Wiratni; Angenent, Largus T.

2014-01-01

A government-sponsored initiative in Indonesia to design and implement low-cost anaerobic digestion systems resulted in 21 full-scale systems with the aim to satisfy the cooking fuel demands of rural households owning at least one cow. The full-scale design consisted of a 0.3 m diameter PVC pipe, which was operated as a conventional plug-flow system. The system generated enough methane to power a cooking stove for ∼1 h. However, eventual clogging from solids accumulation inside the bioreactor proved to be a major drawback. Here, we improved the digester configuration to remedy clogging while maintaining system performance. Controlled experiments were performed using four 9-L laboratory-scale digesters operated at a temperature of 27 ± 1°C, a volatile solids loading rate of 2.0 g VS·L−1 ·day−1, and a 21-day hydraulic retention time. Two of the digesters were replicates of the original design (control digesters), while the other two digesters included internal mixing or effluent recycle (experimental digesters). The performance of each digester was compared based on methane yields, VS removal efficiencies, and steady-state solids concentrations during an operating period of 311 days. Statistical analyses revealed that internal mixing and effluent recycling resulted in reduced solids accumulation compared to the controls without diminishing methane yields or solids removal efficiencies. PMID:24715809

[Disorders affecting the digestive system during sleep].

PubMed

Galdón Castillo, A; Galera Mendoza, L; Egea González, A; González Olsen, A; Sánchez González, Y; Paniagua Soto, J

In this work we review the major publications dealing with disorders that affect the digestive system and how they are related to sleep. Development. Sleep disorders occur in 12-25% of the general population and a large percentage of these pathologies are related to disorders of the digestive system. We review the different pathologies and symptoms linked to the digestive tract that give rise to sleep disorders. The study first examined the upper digestive tract, that is, the teeth and teeth grinding, and we then went on to look at gastroesophageal reflux, esophageal motility disorders, peptic ulcer disease, cholelithiasis, gastric ulcer, irritable bowel, proctalgia, the extent to which the disorders are related to pregnancy, disorders at the paediatric age and eating disorders. Digestive pains during sleep form a heterogeneous clinical picture that disrupts patients' sleep and exerts an influence on their quality of daily living, which in turn may affect sleep and favour the appearance of pains. To date these symptoms have received relatively little attention, but in the few studies that have been carried out, it has not been possible to establish with any degree of accuracy whether sleep and the digestive system share common control mechanisms or not. Research into this type of disorders could help to prevent the appearance of the complications that appear in these clinical pictures.

Anaerobic sludge digestion with a biocatalytic additive

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, S.; Henry, M.P.; Fedde, P.A.

1982-01-01

The objective of this research was to evaluate the effects of a lactobacillus additive an anaerobic sludge digestion under normal, variable, and overload operating conditions. The additive was a whey fermentation product of an acid-tolerant strain of Lactobacillus acidophilus fortified with CaCO/sub 3/, (NH/sub 4/)/sub 2/HPO/sub 4/, ferrous lactate, and lactic acid. The lactobacillus additive is multifunctional in nature and provides growth factors, metabolic intermediates, and enzymes needed for substrate degradation and cellular synthesis. The experimental work consisted of several pairs of parallel mesophilic (35/sup 0/C) digestion runs (control and test) conducted in five experimental phases. Baseline runs without themore » additive showed that the two experimental digesters had the same methane content, gas production rate (GPR), and ethane yield. The effect of the additive was to increase methane yield and GPR by about 5% (which was statistically significant) during digester operation at a loading rate (LR) of 3.2 kg VS/m/sup 3/-day and a hydraulic retention time (HRT) of 14 days. Data collected from the various experimental phases showed that the biochemical additive increased methane yield, gas production rate, and VS reduction, and decreased volatile acids accumulation. In addition, it enhanced digester buffer capacity and improved the fertilizer value and dewatering characteristics of the digested residue.« less

Dietary fiber and digestive health in children.

PubMed

Korczak, Renee; Kamil, Alison; Fleige, Lisa; Donovan, Sharon M; Slavin, Joanne L

2017-04-01

Digestive health is an expanding area in nutrition research due to the interest in how food components such as fiber affect gastrointestinal tolerance, stool form, defecation frequency, transit time, and gut microbial composition and metabolic activity. In children, however, digestive health studies that intervene with dietary fiber are limited due to legal and ethical concerns. To better understand if fiber improves digestive health in children, a literature review was conducted to answer the following research question: What are the effect(s) of fiber-containing foods and/or supplements on digestive health outcomes in children? A search of the PubMed database identified a total of 12 studies that fit the inclusion criteria established for this review. Most of the evidence in children shows beneficial effects of partially hydrolyzed guar gum, glucomannan, and bran on digestive health outcomes; however, the existing evidence is not conclusive. Furthermore, limited data exists on the effect of whole-grain sources of dietary fiber, such as oats. Additional well-designed intervention trials are needed to determine whether outcomes of digestive health such as stool form, gastrointestinal tolerance, and stool frequency are improved by increasing the fiber content of children's diets with whole-grain sources. © The Author(s) 2017. Published by Oxford University Press on behalf of the International Life Sciences Institute. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Biogas by semi-continuous anaerobic digestion of food waste.

PubMed

Zhang, Cunsheng; Su, Haijia; Wang, Zhenbin; Tan, Tianwei; Qin, Peiyong

2015-04-01

The semi-continuous anaerobic digestion of food waste was investigated in 1-L and 20-L continuously stirred tank reactors (CSTRs), to identify the optimum operation condition and the methane production of the semi-continuous anaerobic process. Results from a 1-L digester indicated that the optimum organic loading rate (OLR) for semi-continuous digestion is 8 g VS/L/day. The corresponding methane yield and chemical oxygen demand (COD) reduction were 385 mL/g VS and 80.2 %, respectively. Anaerobic digestion was inhibited at high OLRs (12 and 16 g VS/L/day), due to volatile fatty acid (VFA) accumulation. Results from a 20-L digester indicated that a higher methane yield of 423 mL/g VS was obtained at this larger scale. The analysis showed that the methane production at the optimum OLR fitted well with the determined kinetics equation. An obvious decrease on the methane content was observed at the initial of digestion. The increased metabolization of microbes and the activity decrease of methanogen caused by VFA accumulation explained the lower methane content at the initial of digestion.

Horse manure as feedstock for anaerobic digestion.

PubMed

Hadin, Sa; Eriksson, Ola

2016-10-01

Horse keeping is of great economic, social and environmental benefit for society, but causes environmental impacts throughout the whole chain from feed production to manure treatment. According to national statistics, the number of horses in Sweden is continually increasing and is currently approximately 360,000. This in turn leads to increasing amounts of horse manure that have to be managed and treated. Current practices could cause local and global environmental impacts due to poor performance or lack of proper management. Horse manure with its content of nutrients and organic material can however contribute to fertilisation of arable land and recovery of renewable energy following anaerobic digestion. At present anaerobic digestion of horse manure is not a common treatment. In this paper the potential for producing biogas and biofertiliser from horse manure is analysed based on a thorough literature review in combination with mathematical modelling and simulations. Anaerobic digestion was chosen as it has a high degree of resource conservation, both in terms of energy (biogas) and nutrients (digestate). Important factors regarding manure characteristics and operating factors in the biogas plant are identified. Two crucial factors are the type and amount of bedding material used, which has strong implications for feedstock characteristics, and the type of digestion method applied (dry or wet process). Straw and waste paper are identified as the best materials in an energy point of view. While the specific methane yield decreases with a high amount of bedding, the bedding material still makes a positive contribution to the energy balance. Thermophilic digestion increases the methane generation rate and yield, compared with mesophilic digestion, but the total effect is negligible. Copyright © 2016. Published by Elsevier Ltd.

Anaerobic sludge digestion in the presence of lactobacillus additive

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, S.; Klass, D.L.

1980-01-01

A laboratory evaluation of a lactobacillus fermentation product was performed to study its effects as an additive on the anaerobic digestion of sewage sludge under conventional and overloaded high-rate conditions. The overloaded conditions were those experienced in commercial municipal digesters. It was concluded from this work that the use of the additive at low concentrations permits digester operation at least up to double the loading of untreated digesters and at higher methane yields and volatile solids reductions without affecting effluent quality. The additive also imparts iproved digester stability and rapid response to loading rate and detention time excursions and upsets.more » The beneficial effets of the additive observed in the laboratory remain to be established with other feeds such as biomass, and in large-scale commercial digestion tests that are now in progress.« less

Simulating Dinosaur Digestion in the Classroom.

ERIC Educational Resources Information Center

Peczkis, Jan

1992-01-01

Describes an activity for use with a chapter on dinosaurs, prehistoric life, or digestion in which children make simulated dinosaur stomachs to gain hands-on experience about the theory of gastroliths, or stomach stones. Presents teacher information about the digestive processes in birds and dinosaurs. Discusses materials needed, objectives,…

Building Databases for Education. ERIC Digest.

ERIC Educational Resources Information Center

Klausmeier, Jane A.

This digest provides a brief explanation of what a database is; explains how a database can be used; identifies important factors that should be considered when choosing database management system software; and provides citations to sources for finding reviews and evaluations of database management software. The digest is concerned primarily with…

Effects of dietary Pb on accumulation, histopathology, and digestive enzyme activities in the digestive system of tilapia (Oreochromis niloticus).

PubMed

Dai, Wei; Du, Huahua; Fu, Linglin; Jin, Chengguan; Xu, Zirong; Liu, Huitao

2009-02-01

With the increasing occurrence of dietary lead (Pb) contamination in aquatic environment, threat of the dietary Pb toxicity to aquatic organisms attracted more attention. In this study, after being exposed to dietary Pb at concentrations of 0, 100, 400, and 800-microg/g dry weight for 60 days, the groups of tilapia (Oreochromis niloticus) were sacrificed and sampled to analyze the effects of dietary Pb on accumulation, histopathology, and digestive enzyme activities in tissues of the digestive system. The results showed that the Pb accumulation in tissues increased with the dietary Pb concentrations. Moreover, Pb accumulated in sampled tissues in the following order: intestine > stomach > liver. By observation of liver histological sections in optical microscope, lesions could be detected in the Pb-contaminated groups. It was also demonstrated that the inhibitory effect of dietary Pb on digestive enzyme activities was dietary Pb concentration dependent. Different degrees of inhibition of enzyme activities were exhibited in sampled tissues. It was indicated that digestive enzyme activities in the digestive system might be considered as the potential biomarkers of dietary Pb contamination in tilapia.

Enhanced methane production from Taihu Lake blue algae by anaerobic co-digestion with corn straw in continuous feed digesters.

PubMed

Zhong, Weizhang; Chi, Lina; Luo, Yijing; Zhang, Zhongzhi; Zhang, Zhenjia; Wu, Wei-Min

2013-04-01

Anaerobic digestion of Taihu blue algae was tested in laboratory scale, continuous feed digesters (hydraulic retention time 10 days) at 35°C and various organic loading rates (OLR). The methane production and biomass digestion performed well at OLR below 4.00 gVSL(-1)d(-1) but deteriorated as OLR increased due to the increased ammonia concentration, causing inhibition mainly to acetate and propionate degradation. Supplementing corn straw as co-feedstock significantly improved the digestion performance. The optimal C/N ratio for the co-digestion was 20:1 at OLR of 6.00 gVSL(-1) d(-1). Methane yield of 234 mL CH4 gVS(-1) and methane productivity of 1404 mL CH4 L(-1) d(-1) were achieved with solid removal of 63%. Compared with the algae alone, the methane productivity was increased by 46% with less accumulation of ammonia and fatty acids. The reactor rate-limiting step was acetate and propionate degradation. Copyright © 2013 Elsevier Ltd. All rights reserved.

Treating an aged pentachlorophenol- (PCP-) contaminated soil through three sludge handling processes, anaerobic sludge digestion, post-sludge digestion and sludge land application.

PubMed

Chen, S T; Berthouex, P M

2001-01-01

The extensive pentachlorophenol (PCP) contamination and its increasing treatment costs motivate the search for a more competitive treatment alternative. In a municipal wastewater treatment plant, anaerobic sludge-handling processes comprises three bio-processes, namely the anaerobic sludge digestion, post-sludge digestion and sludge land application, which reduce sludge organic content and make sludge a good fertilizer for land application. Availability and effectiveness make the anaerobic sludge handling processes potential technologies to treat PCP-contaminated soil. The technical feasibility of using anaerobic sludge bioprocesses was studied by treating PCP soil in two pilot digesters to simulate the primary sludge digestion, in serum bottles to mimic the post-sludge digestion, and in glass pans to represent the on-site sludge application. For primary digestion, the results showed that up to 0.98 and 0.6 mM of chemical and soil PCP, respectively, were treated at nearly 100% and 97.5% efficiencies. The PCP was transformed 95% to 3-MCP, 4.5% to 3,4-DCP, and 0.5% to 3,5-DCP. For post-digestion, 100% pure chemical PCP and greater than 95% soil PCP were removed in less than 6 months with no chlorophenol residues of any kind. Complete removal of PCP by-products makes this process a good soil cleanup method. For on-site treatment, PCP was efficiently treated by multiple sludge application; however, the PCP residue was observed due to the high initial PCP content in soil. Overall, more mass PCP per unit sludge per day was processed using the primary sludge digestion than the on-site soil treatment or post-sludge digestion. And, sludge acclimation resulted in better PCP treatment efficiencies with all three processes.

Proteome analysis of pitcher fluid of the carnivorous plant Nepenthes alata.

PubMed

Hatano, Naoya; Hamada, Tatsuro

2008-02-01

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.

Anaerobic sludge digestion with a biocatalytic additive. [Lactobacillus acidophilus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ghosh, S.; Henry, M.P.; Fedde, P.A.

1982-01-01

Aimed at improving the process operating characteristics of anaerobic digestion for sludge stabilization and SNG production, this study evaluates the effects of a lactobacillus additive under normal, variable, and overload conditions. This whey fermentation product of an acid-tolerant strain of L. acidophilus fortified with CoCO/sub 3/, (NH/sub 4/)/sub 2/HPO/sub 4/, ferrous lactate, and lactic acid provides growth factors, metabolic intermediates, and enzymes needed for substrate degradation and cellular synthesis. Data indicate that the biochemical additive increases methane yield, gas production rate, and volatile solids reduction; decreases volatile acids accumulation; enhances the digester buffer capacity; and improves the fertilizer value andmore » dewatering characteristics of the digested residue. Digester capacities could be potentially doubled when the feed is so treated. Results of field tests with six full-scale digesters confirm observations made with bench-scale digesters.« less

Accelerator system and method of accelerating particles

NASA Technical Reports Server (NTRS)

Wirz, Richard E. (Inventor)

2010-01-01

An accelerator system and method that utilize dust as the primary mass flux for generating thrust are provided. The accelerator system can include an accelerator capable of operating in a self-neutralizing mode and having a discharge chamber and at least one ionizer capable of charging dust particles. The system can also include a dust particle feeder that is capable of introducing the dust particles into the accelerator. By applying a pulsed positive and negative charge voltage to the accelerator, the charged dust particles can be accelerated thereby generating thrust and neutralizing the accelerator system.

[Anaerobic co-digestion of corn stalk and vermicompost].

PubMed

Chen, Guang-yin; Zheng, Zheng; Zou, Xing-xing; Fang, Cai-xia; Luo, Yan

2010-02-01

The characteristics of corn stalk digested alone at different total solid (TS) loading rates and co-digestion of various proportions of corn stalk and vermicompost were investigated by batch model at 35 degrees C +/- 1 degrees C. The organic loading rates (OLRs) studied were in the range of 1.2%-6.0% TS and increasing proportions of vermicompost from 20% to 80% TS. A maximum methane yield of corn stalk digested alone was 217.60 mL/g obtained at the TS loading rate of 4.8%. However, when the TS loading rate was 6.0%, the anaerobic system was acidified and the lowest pH value was 5.10 obtained on day 4 and the biogas productivity decreased. Furthermore, co-digestion of vermicompost and corn stalk in varying proportions were investigated at constant of 6.0% TS. Co-digestion with vermicompost improved the biodegradability of corn stalk and the methane yield was improved by 4.42%-58.61%, and led to higher pH values, higher volatile fatty acids (VFAs) concentration and lower alkalinity content compared with corn stalk digested alone. The maximum biogas yield and methane yield of 410.30 mL/g and 259. 35 mL/g were obtained for 40% vermicompost and 60% corn stalk respectively. Compared with corn stalk digested alone, co-digested with vermicompost didn' t affect methane content and the fermentation type, but promoted the destruction of crystalline of cellulose and the highest destruction rate was 29.36% for 40% vermicompost and 60% corn stalk. Therefore, adding vermicompost was beneficial for the decomposition and increasing the biotransformation rate of corn stalk.

Digestion of starch in a dynamic small intestinal model.

PubMed

Jaime-Fonseca, M R; Gouseti, O; Fryer, P J; Wickham, M S J; Bakalis, S

2016-12-01

The rate and extent of starch digestion have been linked with important health aspects, such as control of obesity and type-2 diabetes. In vitro techniques are often used to study digestion and simulated nutrient absorption; however, the effect of gut motility is often disregarded. The present work aims at studying fundamentals of starch digestion, e.g. the effect of viscosity on digestibility, taking into account both biochemical and engineering (gut motility) parameters. New small intestinal model (SIM) that realistically mimics gut motility (segmentation) was used to study digestibility and simulated oligosaccharide bio accessibility of (a) model starch solutions; (b) bread formulations. First, the model was compared with the rigorously mixed stirred tank reactor (STR). Then the effects of enzyme concentration/flow rate, starch concentration, and digesta viscosity (addition of guar gum) were evaluated. Compared to the STR, the SIM showed presence of lag phase when no digestive processes could be detected. The effects of enzyme concentration and flow rate appeared to be marginal in the region of mass transfer limited reactions. Addition of guar gum reduced simulated glucose absorption by up to 45 % in model starch solutions and by 35 % in bread formulations, indicating the importance of chyme rheology on nutrient bioaccessibility. Overall, the work highlights the significance of gut motility in digestive processes and offers a powerful tool in nutritional studies that, additionally to biochemical, considers engineering aspects of digestion. The potential to modulate food digestibility and nutrient bioaccessibility by altering food formulation is indicated.

Inactivation of dairy manure-borne pathogens by anaerobic digestion

USDA-ARS?s Scientific Manuscript database

Background: Anaerobic digestion of animal manure has the potential to inactivate enteric pathogens, thereby reducing exposures to livestock and humans when the products of digestion are disposed by land-spreading or irrigation or returned to livestock uses such as bedding. Data on digester effectiv...

Selective decontamination of the digestive tract.

PubMed

Krueger, Wolfgang A; Unertl, Klaus E

2002-04-01

Ventilator-associated pneumonia usually originates from the patient's oropharyngeal microflora. In selective digestive decontamination, topical antibiotics are applied to the oropharynx and stomach for prevention of pneumonia and other infections, possibly reducing infection-related mortality. Selective digestive decontamination is also used for the prevention of gut-derived infections in acute necrotizing pancreatitis and liver transplantation. Despite numerous clinical trials, selective digestive decontamination remains controversial. Reduction of the incidence of pneumonia is accepted, but the extent of reduction is debated. Mortality was not reduced in most individual trials, but this finding was calculated in meta-analyses, especially for combined use of topical and systemic antibiotics in surgical ICU patients. Some investigators reported increased resistance and a shift to Gram-positive pathogens. Today, it appears that selective means not only selective suppression of pathogenic bacteria but also selection of appropriate groups of patients for underlying diseases and severity of illness, and selection of ICUs, where the endemic resistance patterns might allow the use of selective digestive decontamination at a relatively low risk for increased selection pressure.

Anaerobic digestion and digestate use: accounting of greenhouse gases and global warming contribution.

PubMed

Møller, Jacob; Boldrin, Alessio; Christensen, Thomas H

2009-11-01

Anaerobic digestion (AD) of source-separated municipal solid waste (MSW) and use of the digestate is presented from a global warming (GW) point of view by providing ranges of greenhouse gas (GHG) emissions that are useful for calculation of global warming factors (GWFs), i.e. the contribution to GW measured in CO(2)-equivalents per tonne of wet waste. The GHG accounting was done by distinguishing between direct contributions at the AD facility and indirect upstream or downstream contributions. GHG accounting for a generic AD facility with either biogas utilization at the facility or upgrading of the gas for vehicle fuel resulted in a GWF from -375 (a saving) to 111 (a load) kg CO(2)-eq. tonne(-1) wet waste. In both cases the digestate was used for fertilizer substitution. This large range was a result of the variation found for a number of key parameters: energy substitution by biogas, N(2)O-emission from digestate in soil, fugitive emission of CH( 4), unburned CH(4), carbon bound in soil and fertilizer substitution. GWF for a specific type of AD facility was in the range -95 to -4 kg CO(2)-eq. tonne(-1) wet waste. The ranges of uncertainty, especially of fugitive losses of CH(4) and carbon sequestration highly influenced the result. In comparison with the few published GWFs for AD, the range of our data was much larger demonstrating the need to use a consistent and robust approach to GHG accounting and simultaneously accept that some key parameters are highly uncertain.

The digestive tract of Drosophila melanogaster.

PubMed

Lemaitre, Bruno; Miguel-Aliaga, Irene

2013-01-01

The digestive tract plays a central role in the digestion and absorption of nutrients. Far from being a passive tube, it provides the first line of defense against pathogens and maintains energy homeostasis by exchanging neuronal and endocrine signals with other organs. Historically neglected, the gut of the fruit fly Drosophila melanogaster has recently come to the forefront of Drosophila research. Areas as diverse as stem cell biology, neurobiology, metabolism, and immunity are benefitting from the ability to study the genetics of development, growth regulation, and physiology in the same organ. In this review, we summarize our knowledge of the Drosophila digestive tract, with an emphasis on the adult midgut and its functional underpinnings.

Lactose digestion from yogurt: mechanism and relevance.

PubMed

Savaiano, Dennis A

2014-05-01

Yogurt is traditionally consumed throughout the world among populations who are seemingly unable to digest lactose. This review provides a historical overview of the studies that show lactose digestion and tolerance from yogurt by lactose-intolerant people. The lactose in yogurt is digested more efficiently than other dairy sources of lactose because the bacteria inherent in yogurt assist with its digestion. The bacterial lactase survives the acidic conditions of the stomach, apparently being physically protected within the bacterial cells and facilitated by the buffering capacity of yogurt. The increasing pH as the yogurt enters the small intestine and a slower gastrointestinal transit time allow the bacterial lactase to be active, digesting lactose from yogurt sufficiently to prevent symptoms in lactose-intolerant people. There is little difference in the lactase capability of different commercial yogurts, because they apparently contain Lactobacillus bulgaricus and Streptococcus thermophilus in sufficient quantities (10(8) bacteria/mL). However, Lactobacillus acidophilus appears to require cell membrane disruption to physically release the lactase. Compared with unflavored yogurts, flavored yogurts appear to exhibit somewhat reduced lactase activity but are still well tolerated.

Integration of pyrolysis and anaerobic digestion--use of aqueous liquor from digestate pyrolysis for biogas production.

PubMed

Hübner, Tobias; Mumme, Jan

2015-05-01

Anaerobic digestion of aqueous pyrolysis liquor derived from pyrolysis of solid digestate was tested in batch mode using an un-adapted inoculum. Three pyrolysis liquors produced at 330°C, 430°C and 530°C in four COD-based concentrations of 3, 6, 12 and 30 g L(-1) were investigated. The three lower concentrations showed considerable biogas production, whereas the 30 g L(-1) dosage caused process inhibition. The highest methane yield of 199.1±18.5 mL g(COD)(-1) (COD removal: 56.9±5.3%) was observed for the 330°C pyrolysis liquor, followed by the 430°C sample with only slightly lower values. The 530°C sample dropped to a yield of 129.3±19.7 mL g(COD)(-1) (COD removal: 36.9±5.6%). Most VOCs contained in the pyrolysis liquor (i.e. furfural, phenol, catechol, guaiacol, and levoglucosan) were reduced below detection limit (cresol by 10-60%). Consequently, integrated pyrolysis and anaerobic digestion in addition to thermochemical conversion of digestate also promises bioconversion of pyrolysis liquors. Copyright © 2015 Elsevier Ltd. All rights reserved.

Function of obestatin in the digestive system.

PubMed

Xing, Yue-Xian; Yang, Liu; Kuang, Hong-Yu; Gao, Xin-Yuan; Liu, Hao-Ling

2017-02-01

Physical health has a direct relationship with digestive function. Any abnormalities in the link may cause malnutrition, endocrine disorders, and the decline of organ functions. Obestatin, a biologically active peptide, is encoded by the ghrelin gene. Most studies suggest that obestatin is a pleiotropic peptide, which acts by suppressing the motility of the gastrointestinal tract, regulating the secretion of insulin, reducing inflammation and apoptosis, and promoting proliferation. These characteristics suggest that obestatin may represent an efficient way to prevent the occurrence and development of some digestive diseases. However, the functions of obestatin are not clear, and even appear to be contradictory. The aim of this review was to discuss the close relationship between obestatin and the digestive system, and to provide a unique perspective for the future development of obestatin relative to digestive diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

Comparison of amino acid digestibility of feedstuffs determined with the precision-fed cecectomized rooster assay and the standardized ileal amino acid digestibility assay.

PubMed

Kim, E J; Utterback, P L; Applegate, T J; Parsons, C M

2011-11-01

The objective of this study was to evaluate and compare amino acid digestibility of several feedstuffs using 2 commonly accepted methods: the precision-fed cecectomized rooster assay (PFR) and the standardized ileal amino acid assay (SIAAD). Six corn, 6 corn distillers dried grains with or without solubles (DDGS/DDG), one wet distillers grains, one condensed solubles, 2 meat and bone meal (MBM) and a poultry byproduct meal were evaluated. Due to insufficient amounts, the wet distillers grains and condensed solubles were only evaluated in roosters. Standardized amino acid digestibility varied among the feed ingredients and among samples of the same ingredient for both methods. For corn, there were generally no differences in amino acid digestibility between the 2 methods. When differences did occur, there was no consistent pattern among the individual amino acids and methods. Standardized amino acid digestibility was not different between the 2 methods for 4 of the DDG samples; however, the PFR yielded higher digestibility values for a high protein DDG and a conventionally processed DDGS. The PFR yielded higher amino acid digestibility values than the SIAAD for several amino acids in 1 MBM and the poultry byproduct meal, but it yielded lower digestibility values for the other MBM. Overall, there were no consistent differences between methods for amino acid digestibility values. In conclusion, the PFR and SIAAD methods are acceptable for determining amino acid digestibility. However, these procedures do not always yield similar results for all feedstuffs evaluated. Thus, further studies are needed to understand the underlying causes in this variability.

[Expression of carcinoembryonic antigen receptor in digestive organs].

PubMed

Zhao, Hui-min; Zhang, Sen; Gao, Feng

2010-08-01

To explore the significance of the expression of carcinoembryonic antigen receptors (CEAR) in digestive organs. Specimens were procured from 20 male BALB/c mice including esophagus, small intestine, stomach, colon, pancreas, and liver. Kupffer cells were obtained by density gradient centrifugation following enzymatic digestion of the fresh liver specimen. Immunohistochemistry and immunocytochemistry methods were used to detect CEAR in those organs or Kupffer cells. CEAR was found both in cytoplasm and nuclei of the digestive tract mucosal epithelial cells and pancreas islet cells, but only in the cytoplasm of liver cells, Kupffer cells, and smooth muscle cells of the whole digestive tract. The mean ranks of CEAR expression were 174.33 in the mucosal epithelial cells of colon, 160.70 in epithelial cells of small intestine, 139.18 in Kupffer cells, 137.43 in pancreas islet cells, 131.70 in liver cells, 124.23 in gastric epithelial cells, 77.15 in esophageal epithelial cells and 57.80-71.00 in smooth muscle cells of the entire digestive tract examined. There were significantly differences in the CEAR expression intensity among those positive cells (chi2=99.58, P<0.01) while CEAR was not present in submucosal connective tissue cells, pancreatic exocrine cells, or hepatic sinusoid endothelial cells. There are significantly differences in the expression of CEAR in the main digestive organs according to the different tissue and cells, which may play an important role in the carcinogenesis and hepatic metastasis from tumors of the digestive system.

Fate of Trace Metals in Anaerobic Digestion.

PubMed

Fermoso, F G; van Hullebusch, E D; Guibaud, G; Collins, G; Svensson, B H; Carliell-Marquet, C; Vink, J P M; Esposito, G; Frunzo, L

2015-01-01

A challenging, and largely uncharted, area of research in the field of anaerobic digestion science and technology is in understanding the roles of trace metals in enabling biogas production. This is a major knowledge gap and a multifaceted problem involving metal chemistry; physical interactions of metal and solids; microbiology; and technology optimization. Moreover, the fate of trace metals, and the chemical speciation and transport of trace metals in environments--often agricultural lands receiving discharge waters from anaerobic digestion processes--simultaneously represents challenges for environmental protection and opportunities to close process loops in anaerobic digestion.

The Protein Composition of the Digestive Fluid from the Venus Flytrap Sheds Light on Prey Digestion Mechanisms*

PubMed Central

Schulze, Waltraud X.; Sanggaard, Kristian W.; Kreuzer, Ines; Knudsen, Anders D.; Bemm, Felix; Thøgersen, Ida B.; Bräutigam, Andrea; Thomsen, Line R.; Schliesky, Simon; Dyrlund, Thomas F.; Escalante-Perez, Maria; Becker, Dirk; Schultz, Jörg; Karring, Henrik; Weber, Andreas; Højrup, Peter; Hedrich, Rainer; Enghild, Jan J.

2012-01-01

The Venus flytrap (Dionaea muscipula) is one of the most well-known carnivorous plants because of its unique ability to capture small animals, usually insects or spiders, through a unique snap-trapping mechanism. The animals are subsequently killed and digested so that the plants can assimilate nutrients, as they grow in mineral-deficient soils. We deep sequenced the cDNA from Dionaea traps to obtain transcript libraries, which were used in the mass spectrometry-based identification of the proteins secreted during digestion. The identified proteins consisted of peroxidases, nucleases, phosphatases, phospholipases, a glucanase, chitinases, and proteolytic enzymes, including four cysteine proteases, two aspartic proteases, and a serine carboxypeptidase. The majority of the most abundant proteins were categorized as pathogenesis-related proteins, suggesting that the plant's digestive system evolved from defense-related processes. This in-depth characterization of a highly specialized secreted fluid from a carnivorous plant provides new information about the plant's prey digestion mechanism and the evolutionary processes driving its defense pathways and nutrient acquisition. PMID:22891002

Modified Anaerobic Digestion Model No.1 for dry and semi-dry anaerobic digestion of solid organic waste.

PubMed

Liotta, Flavia; Chatellier, Patrice; Esposito, Giovanni; Fabbricino, Massimiliano; Frunzo, Luigi; van Hullebusch, Eric D; Lens, Piet N L; Pirozzi, Francesco

2015-01-01

The role of total solids (TS) content in anaerobic digestion of selected complex organic matter, e.g. rice straw and food waste, was investigated. A range of TS from wet (4.5%) to dry (23%) was evaluated. A modified version of the Anaerobic Digestion Model No.1 for a complex organic substrate is proposed to take into account the effect of the TS content on anaerobic digestion. A linear function that correlates the kinetic constants of three specific processes (i.e. disintegration, acetate and propionate up-take) was included in the model. Results of biomethanation and volatile fatty acids production tests were used to calibrate the proposed model. Model simulations showed a good agreement between numerical and observed data.

Digestive system fistula: a problem still relevant today.

PubMed

Głuszek, Stanisław; Korczak, Maria; Kot, Marta; Matykiewicz, Jarosław; Kozieł, Dorota

2011-01-01

Digestive system fistula originates most frequently as a complication after surgical procedures, less often occurs in the course of inflammatory diseases, but it can also result from neoplasm and injuries. THE AIM OF THE STUDY was to analyze the causes and retrospectively assess the perioperative procedures as well as the results of digestive system fistula treatment. MATERIAL AND METHODS. Own experience in digestive system fistula treatment was presented. The subject group consisted of 32 patients treated at the General Surgery, Oncology and Endocrinology Clinical Department between 01.05.2005 and 30.04.2010 due to different digestive tract diseases. The causes of the occurrence of digestive system fistula, methods and results of treatment were analyzed. RESULTS. The analysis covered 32 patients with digestive system fistula, among them 15 men and 17 women. Average age for men was 57 years (20-78), and for women 61 years (24-88). In 11 patients idiopathic fistula causally connected with primary inflammatory disease (7 cases) and with neoplasm (4 cases) was diagnosed, in 19 patients fistula was the result of complications after surgery, in 2 - after abdominal cavity injury. Recovery from fistula was achieved in 23 patients (72%) with the use of individually planned conservative therapy (TPN, EN, antibiotics, drainage, and others) and surgery, depending on the needs of individual patient. 5 patients (16%) died, whereas in 4 left (12%) recovery wasn't achieved (fistula in palliative patients, with advanced stages of neoplasm - bronchoesophageal fistula, the recurrence of uterine carcinoma). CONCLUSIONS. Recently the results of digestive system fistula treatment showed an improvement which manifests itself in mortality decrease and shortening of fistula healing time. Yet, digestive system fistula as a serious complication still poses a very difficult surgical problem.

How does free ammonia-based sludge pretreatment improve methane production from anaerobic digestion of waste activated sludge.

PubMed

Wang, Dongbo; Liu, Bowen; Liu, Xuran; Xu, Qiuxiang; Yang, Qi; Liu, Yiwen; Zeng, Guangming; Li, Xiaoming; Ni, Bing-Jie

2018-09-01

Previous studies reported that free ammonia (FA) pretreatment could improve methane production from anaerobic digestion of waste activated sludge (WAS) effectively. However, details of how FA pretreatment improves methane production are poorly understood. This study therefore aims to reveal the underlying mechanisms of FA pretreatment affecting anaerobic digestion of WAS through a series of batch tests using either real sludge or synthetic media as the digestion substrates at different pH values. At pH 8.5 level, with an increase of FA level from 18.5 to 92.5 mg/L (i.e., NH+ 4-N: 100-500 mg/L; pH 8.5) the maximum methane yield varied between 194.0 ± 3.9 and 196.9 ± 7.7 mL/g of VSS (25 °C, 1 atm). At pH 9.5 or 10 level, however, with an increase of initial FA level from 103.2 to 516.2 mg/L, the maximal methane yield increased linearly. The mechanism studies revealed that FA pretreatment at high levels not only accelerated the disintegration of WAS but also enhanced the biodegradability of WAS. Although pH in the digesters was adjusted to 7.0 ± 0.1, the high levels of NH+ 4-N added or released led to substantial levels of residual FA ranging from 4.4 to 11.6 mg/L. It was found that this level of FA inhibited homoacetogenesis and methanogenesis significantly, though hydrolysis, acidogenesis, and acetogenesis processes were unaffected largely. Further analyses showed that the inhibition constant of FA to substrate degradation was in the sequence of dextran > glucose > hydrogen > acetate, indicating the methanogenesis process was more sensitive to FA. Copyright © 2018 Elsevier Ltd. All rights reserved.

Digestive toxicities after palliative three-dimensional conformal radiation therapy (3D-CRT) for cervico-thoracic spinal metastases.

PubMed

Peyraga, Guillaume; Caron, Delphine; Lizee, Thibaut; Metayer, Yann; Septans, Anne-Lise; Pointreau, Yoann; Denis, Fabrice; Ganem, Gerard; Lafond, Cedrik; Roche, Sophie; Dupuis, Olivier

2018-06-01

The palliative treatment for cervico-thoracic spinal metastases is based on a three-dimensional conformal radiation therapy (3D-CRT). Digestive toxicities are common and cause a clinical impact frequently underestimated in patients. We performed a retrospective study of digestive side effects occurring after palliative 3D-CRT for cervico-thoracic spinal metastases. All patients receiving palliative 3D-CRT at Jean Bernard Center from January 2013 to December 2014 for spinal metastases between the 5th cervical vertebra (C5) and the 12th thoracic vertebra (T12) were eligible. Three-dimensional conformal RT was delivered by a linear accelerator (CLINAC, Varian). Premedication to prevent digestive toxicities was not used. Adverse events ("esophagitis" and "nausea and/or vomiting") were evaluated according to the NCI-CTCae (version 4). From January 2013 to December 2014, 128 patients met the study criteria. The median age was 68.6 years [31.8; 88.6]. Most patients (84.4%) received 30 Gy in 10 fractions. The median overall time of treatment was 13 days [3-33]. Forty patients (31.3%) suffered from grade ≥ 2 of "esophagitis" (35 grade 2 (27.4%) and 5 grade 3 (3.9%)). Eight patients (6.3%) suffered from grade ≥ 2 of "nausea and/or vomiting" (6 grade 2 (4.7%), 1 grade 3 (0.8%), and 1 grade 4 (0.8%)). The high incidence of moderate to severe digestive toxicities after palliative 3D-CRT for cervico-thoracic spinal metastases led to consider static or dynamic intensity-modulated radiation therapy (IMRT) to reduce the dose to organ at risk (the esophagus and stomach). Dosimetric studies and implementation in the clinic should be the next steps.

Solute carrier transporters: potential targets for digestive system neoplasms.

PubMed

Xie, Jing; Zhu, Xiao Yan; Liu, Lu Ming; Meng, Zhi Qiang

2018-01-01

Digestive system neoplasms are the leading causes of cancer-related death all over the world. Solute carrier (SLC) superfamily is composed of a series of transporters that are ubiquitously expressed in organs and tissues of digestive systems and mediate specific uptake of small molecule substrates in facilitative manner. Given the important role of SLC proteins in maintaining normal functions of digestive system, dysregulation of these protein in digestive system neoplasms may deliver biological and clinical significance that deserves systemic studies. In this review, we critically summarized the recent advances in understanding the role of SLC proteins in digestive system neoplasms. We highlighted that several SLC subfamilies, including metal ion transporters, transporters of glucose and other sugars, transporters of urea, neurotransmitters and biogenic amines, ammonium and choline, inorganic cation/anion transporters, transporters of nucleotide, amino acid and oligopeptide organic anion transporters, transporters of vitamins and cofactors and mitochondrial carrier, may play important roles in mediating the initiation, progression, metastasis, and chemoresistance of digestive system neoplasms. Proteins in these SLC subfamilies may also have diagnostic and prognostic values to particular cancer types. Differential expression of SLC proteins in tumors of digestive system was analyzed by extracting data from human cancer database, which revealed that the roles of SLC proteins may either be dependent on the substrates they transport or be tissue specific. In addition, small molecule modulators that pharmacologically regulate the functions of SLC proteins were discussed for their possible application in the treatment of digestive system neoplasms. This review highlighted the potential of SLC family proteins as drug target for the treatment of digestive system neoplasms.

Solute carrier transporters: potential targets for digestive system neoplasms

PubMed Central

Xie, Jing; Zhu, Xiao Yan; Liu, Lu Ming; Meng, Zhi Qiang

2018-01-01

Digestive system neoplasms are the leading causes of cancer-related death all over the world. Solute carrier (SLC) superfamily is composed of a series of transporters that are ubiquitously expressed in organs and tissues of digestive systems and mediate specific uptake of small molecule substrates in facilitative manner. Given the important role of SLC proteins in maintaining normal functions of digestive system, dysregulation of these protein in digestive system neoplasms may deliver biological and clinical significance that deserves systemic studies. In this review, we critically summarized the recent advances in understanding the role of SLC proteins in digestive system neoplasms. We highlighted that several SLC subfamilies, including metal ion transporters, transporters of glucose and other sugars, transporters of urea, neurotransmitters and biogenic amines, ammonium and choline, inorganic cation/anion transporters, transporters of nucleotide, amino acid and oligopeptide organic anion transporters, transporters of vitamins and cofactors and mitochondrial carrier, may play important roles in mediating the initiation, progression, metastasis, and chemoresistance of digestive system neoplasms. Proteins in these SLC subfamilies may also have diagnostic and prognostic values to particular cancer types. Differential expression of SLC proteins in tumors of digestive system was analyzed by extracting data from human cancer database, which revealed that the roles of SLC proteins may either be dependent on the substrates they transport or be tissue specific. In addition, small molecule modulators that pharmacologically regulate the functions of SLC proteins were discussed for their possible application in the treatment of digestive system neoplasms. This review highlighted the potential of SLC family proteins as drug target for the treatment of digestive system neoplasms. PMID:29416375

Boosting methane generation by co-digestion of sludge with fruit and vegetable waste: Internal environment of digester and methanogenic pathway.

PubMed

Di Maria, Francesco; Barratta, Martino

2015-09-01

The effects of anaerobic co-digestion of waste-mixed sludge with fruit and vegetable waste (FVW) on the methane generation of a mesophilic digester was investigated. Organic loading rates (OLR) were 1.46kgVS/m(3)day, 2.1kgVS/m(3)day and 2.8kgVS/m(3)day. Increase in the OLR due to FVW co-digestion caused modification of the internal environment of the digester, mainly in terms of N-NH4 (mg/L). Corresponding microbial populations were investigated by metagenomic high-throughput sequencing. Maximum specific bio-methane generation of 435 NLCH4 per kgVS feed was achieved for an OLR of 2.1kgVS/m(3)day, which corresponded to a biomethane generation per kgVS removed of about 1700 NLCH4. In these conditions the methanogenic pathway was dominated by aceticlastic Methanosaeta and hydrogenotrophic/aceticlastic Methanoscarcinae. Ammonia concentration in the digester resulted a key parameter for enhancing syntrophic acetate oxidation, enabling a balanced aceticlastic and hydrogenotrophic/aceticlastic methanogenic pathway. Copyright © 2015 Elsevier Ltd. All rights reserved.

Lactose (mal)digestion evaluated by the 13C-lactose digestion test.

PubMed

Vonk, R J; Lin, Y; Koetse, H A; Huang, C; Zeng, G; Elzinga, H; Antoine, J; Stellaard, F

2000-02-01

The prevalence of genetically determined lactase nonpersistence is based on the results of the lactose H2 breath test. This test, however, is an indirect test, which might lead to misinterpretation. We determined lactase activity in healthy Chinese and Dutch students using a novel 13C-lactose digestion test. The cut-off value of this test was established in a Chinese population with a homogenous genetic background of lactase nonpersistence and was compared with the results obtained in a Caucasian population. Twenty-five grams of a 13C-lactose solution was consumed by 12 known H2-positive and 5 H2-negative Chinese students and 48 Dutch students and, subsequently, 13C-glucose concentration in plasma and H2 excretion in breath were measured. A similar 13C-glucose response curve was found in all Chinese students. The mean response curve in the Dutch students was more pronounced (P < 0.01). The 1 h (peak) plasma 13C-glucose concentration was the best discriminator between lactose digesting and maldigesting subjects. The cut-off level of 2 mmol L-1 13C-glucose in plasma was defined in the H2-positive Chinese students group. Based on the 13C-glucose response the prevalence of lactose maldigestion in the Dutch subjects was 25%; based on the lactose H2 breath test 17%. Using the 13C-lactose digestion test the results demonstrate a higher prevalence of lactose maldigestion in a Caucasian population than indicated by the results of the H2 breath test. A moderate increase in the plasma 13C-glucose concentration after consumption of 13C-lactose in the young adult Chinese subjects indicates a residual lactase activity in that age group, even when a positive H2 breath test result is obtained. These results indicate that the 13C-glucose concentration in plasma more accurately reflects the small intestinal lactose digestion capacity than the lactose H2 breath test.

Low-heat, mild alkaline pretreatment of switchgrass for anaerobic digestion.

PubMed

Jin, Guang; Bierma, Tom; Walker, Paul M

2014-01-01

This study examines the effectiveness of alkaline pretreatment under mild heat conditions (100°C or 212°F) on the anaerobic co-digestion of switchgrass. The effects of alkaline concentration, types of alkaline, heating time and rinsing were evaluated. In addition to batch studies, continuous-feed studies were performed in triplicate to identify potential digester operational problems caused by switchgrass co-digestion while accounting for uncertainty due to digester variability. Few studies have examined anaerobic digestion of switchgrass or the effects of mild heating to enhance alkaline pretreatment prior to biomass digestion. Results indicate that pretreatment can significantly enhance digestion of coarse-ground (≤ 0.78 cm particle size) switchgrass. Energy conversion efficiency as high as 63% was observed, and was comparable or superior to fine-grinding as a pretreatment method. The optimal NaOH concentration was found to be 5.5% (wt/wt alkaline/biomass) with a 91.7% moisture level. No evidence of operational problems such as solids build-up, poor mixing, or floating materials were observed. These results suggest the use of waste heat from a generator could reduce the concentration of alkaline required to adequately pretreat lignocellulosic feedstock prior to anaerobic digestion.

Biomethanation of Sewage Sludge with Food Waste Leachate Via Co-Digestion.

PubMed

Shin, Jingyeong; Kim, Young Beom; Jeon, Jong Hun; Choi, Sangki; Park, In Kyu; Kim, Young Mo

2017-08-28

Anaerobic mono- and co-digestion of sewage sludge and food waste leachate (FWL) were performed by assessing methane production and characterizing microbial communities. Anaerobic digestion (AD) of waste activated sludge (WAS) alone produced the lowest methane (281 ml CH 4 ), but an approximately 80% increase in methane production was achieved via co-digestion of WAS and FWL (506 ml CH 4 ). There were less differences in the diversity of bacterial communities in anaerobic digesters, while archaeal (ARC) and bacterial (BAC) amounts reflected AD performance. Compared with the total ARC and BAC amounts in the mono-digestion of WAS, the ARC and BAC amounts increased two and three times, respectively, during co-digestion of FWL and WAS. In characterized archaeal communities, the dominant ratio of hydrogenotrophic methanogens in the mono-digestion of WAS approached nearly a 1:1 ratio of the two acetoclastic and hydrogenotrophic methanogens in the co-digestion of FWL and WAS. The ARC/BAC ratio in the digesters varied in the range of 5.9% to 9.1%, indicating a positive correlation with the methane production of AD.

Co-digestion of organic solid waste and sludge from sewage treatment.

PubMed

Edelmann, W; Engeli, H; Gradenecker, M

2000-01-01

Solid organic wastes were codigested together with sludge of a sewage treatment plant (STP). In the practical part of the study, a plant to pretreat the organic solid wastes provided by local super markets was constructed at the STP of Frutigen, Switzerland. Up to more than 1 cubic metre of wastes was added to the fermenter of the STP every day. Data collected during 14 months of practical works, showed that for raw fruit and vegetable wastes a two step pretreatment is necessary: First the wastes were chopped and afterwards reduced to a size of 1-2 millimetres, in order to get a homogeneous suspension together with the primary sludge. The vegetable wastes showed excellent digestibility: They seemed to accelerate the digestion process as well as to increase the degree of the anaerobic degradation of the sludge. The energy demand for both, pretreatment and digestion, was 85 kWh/ton of fresh wastes. 20% of the energy was used for the hygienization, a step which does not seem to be necessary for this kind of waste in most of the cases, however. After using the gas for energy conversion, a net yield of 65 kWh/ton of electricity and 166 kWh/ton of heat was measured. Treating cooked kitchen wastes, the net energy production will be higher, because in this case a one step pretreatment will be sufficient. The pretreatment and treatment costs for codigestion on STP's were calculated to be in the range of 55 US$/ton treating half a ton per day and 39 US$/ton treating one ton, respectively. A theoretical feasibility study showed that in Switzerland there is a short term potential on STP's for the codigestion of about 120,000 tons of biogenic wastes per year without big investments. Economic studies about codigestion on agricultural biogas plants showed that the codigestion is a must at the current energy prices, which are far too low for agricultural AD without an additional income by treating solid wastes for third parties.

Influence of resistant starch and slowly digestible starch on rice texture.

USDA-ARS?s Scientific Manuscript database

Rice, comprised mainly of starch, serves as a significant source of caloric energy world-wide, therefore differences in starch digestibility are important to human health. Rice starch consists of three forms based on digestibility, rapidly digestible starch (RDS), slowly digestible starch (SDS), and...

Identification of a major continuous epitope of human alpha crystallin

NASA Technical Reports Server (NTRS)

Takemoto, L.; Emmons, T.; Spooner, B. S. (Principal Investigator)

1992-01-01

Human lens proteins were digested with trypsin or V8 protease, and the resulting peptides resolved on a C18 reverse phase column. Fractions from this column were probed with polyclonal antiserum made against the whole alpha crystallin molecule. Peptides in the seropositive fraction were purified to homogeneity, then characterized by mass spectral analysis and partial Edman degradation. The tryptic and V8 digests contained only one seropositive peptide that was derived from the C-terminal region of the alpha-A molecule. To determine the exact boundaries of the epitope, various size analogues of this region were synthesized and probed with anti-alpha serum. Together, these studies demonstrate that the major continuous epitope of the alpha-A chain includes the sequence KPTSAPS, corresponding to residues 166-172 of the human alpha-A crystallin chain.

The chemical properties and functional role of a lysine residue within the active site of native sodium and potassium ion-activated adenosinetriphosphatase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, K.Y.

1988-01-01

The peptide, HLLVMKGAPER, which contains Lysine 501 of the {alpha} polypeptide can be released from intact sodium and potassium ion activated adenosinetriphosphatase by tryptic digestion. An immunoadsorbent directed against the carboxy-terminal, -GAPER, has been constructed. Sealed, right-side-out vesicles, prepared from canine renal kidneys, were labeled with pyridoxal phosphate and sodium ({sup 3}H)borohydride in the absence or presence of saponin, respectively. Large increases in the incorporation of radioactivity into the peptides bound by the immunoadsorbent were observed in the digest obtained from the vesicles exposed to saponin. From the results of several control experiments examining the labeling reaction it could bemore » concluded that the increase in the extent of modification was due to the cytoplasmic disposition of this segment in the native enzyme.« less

In Situ Enrichment of Phosphopeptides on MALDI Plates Functionalized by Reactive Landing of Zirconium(IV)–n-Propoxide Ions

PubMed Central

Blacken, Grady R.; Volný, Michael; Vaisar, Tomáš; Sadílek, Martin; Tureček, František

2008-01-01

We report substantial in situ enrichment of phosphopeptides in peptide mixtures using zirconium oxide coated plates for detection by MALDI-TOF mass spectrometry. The novel feature of this approach rests on the specific preparation of zirconium oxide coatings using reactive landing on stainless steel support of gas-phase positive ions produced by electrospray of zirconium(IV)–n-propoxide solutions in 1-propanol. Reactive landing was found to produce durable functionalized surfaces for selective phosphopeptide capture and desorption–ionization by MALDI. Enrichment factors on the order of 20–90 were achieved for several monophosphorylated peptides relative to abundant nonphosphorylated peptides in tryptic digests. We demonstrate the ability of the zirconium oxide functionalized MALDI surfaces to facilitate detection of enriched phosphopeptides in mid-femtomole amounts of α-casein digests per MALDI spot. PMID:17569507

Bioaugmentation of overloaded anaerobic digesters restores function and archaeal community.

PubMed

Tale, V P; Maki, J S; Zitomer, D H

2015-03-01

Adding beneficial microorganisms to anaerobic digesters for improved performance (i.e. bioaugmentation) has been shown to decrease recovery time after organic overload or toxicity upset. Compared to strictly anaerobic cultures, adding aerotolerant methanogenic cultures may be more practical since they exhibit higher methanogenic activity and can be easily dried and stored in ambient air for future shipping and use. In this study, anaerobic digesters were bioaugmented with both anaerobic and aerated, methanogenic propionate enrichment cultures after a transient organic overload. Digesters bioaugmented with anaerobic and moderately aerated cultures recovered 25 and 100 days before non-bioaugmented digesters, respectively. Increased methane production due to bioaugmentation continued a long time, with 50-120% increases 6 to 12 SRTs (60-120 days) after overload. In contrast to the anaerobic enrichment, the aerated enrichments were more effective as bioaugmentation cultures, resulting in faster recovery of upset digester methane and COD removal rates. Sixty days after overload, the bioaugmented digester archaeal community was not shifted, but was restored to one similar to the pre-overload community. In contrast, non-bioaugmented digester archaeal communities before and after overload were significantly different. Organisms most similar to Methanospirillum hungatei had higher relative abundance in well-operating, undisturbed and bioaugmented digesters, whereas organisms similar to Methanolinea tarda were more abundant in upset, non-bioaugmented digesters. Bioaugmentation is a beneficial approach to increase digester recovery rate after transient organic overload events. Moderately aerated, methanogenic propionate enrichment cultures were more beneficial augments than a strictly anaerobic enrichment. Copyright © 2014 Elsevier Ltd. All rights reserved.

Morphologic analysis of the zebrafish digestive system.

PubMed

Trotter, Andrew J; Parslow, Adam C; Heath, Joan K

2009-01-01

The zebrafish provides an ideal model for the study of vertebrate organogenesis, including the formation of the digestive tract and its associated organs. Despite optical transparency of embryos, the internal position of the developing digestive system and its close juxtaposition with the yolk initially made morphological analysis relatively challenging, particularly during the first 3 d of development. However, methodologies have been successfully developed to address these problems and comprehensive morphologic analysis of the developing digestive system has now been achieved using a combination of light and fluorescence microscope approaches-including confocal analysis-to visualize wholemount and histological preparations of zebrafish embryos. Furthermore, the expanding number of antibodies that cross-react with zebrafish proteins and the generation of tissue-specific transgenic green fluorescent protein reporter lines that mark specific cell and tissue compartments have greatly enhanced our ability to successfully image the developing zebrafish digestive system.

Biofilms, bubbles and boundary layers - A new approach to understanding cellulolysis in anaerobic and ruminant digestion.

PubMed

Mason, P Michael; Stuckey, David C

2016-11-01

Anaerobic digestion of plant biomass to hydrocarbons could play a major part in meeting the needs of a modern low carbon society, but the cost reductions needed to make it an economically viable technology have been slower to arrive than in other renewable technologies. This is notwithstanding the observation that ruminants carry out the rate limiting hydrolysis step up to 30 times faster than an AD plant, and that bio-mimicry of ruminants could be an important source of innovation. This paper examines a number of factors which may, by focusing emphasis on the physical and chemical environment within cellulolytic biofilms, help accelerate development in the arena. It examines the process of cellulolysis from the perspective of a bacterium attached within a biofilm to a piece of insoluble cellulosic substrate to illustrate the extent of chemical heterogeneity that exists in the film, and between the film and the supernatant, and how this might control the rate of cellulolysis. It suggests several strategies used by ruminants to manage this heterogeneity that may be significant contributors to their effectiveness, and could provide a useful guide to more effective anaerobic digestion. Copyright © 2016. Published by Elsevier Ltd.

Piperazines for peptide carboxyl group derivatization: effect of derivatization reagents and properties of peptides on signal enhancement in matrix-assisted laser desorption/ionization mass spectrometry.

PubMed

Qiao, Xiaoqiang; Sun, Liangliang; Chen, Lingfan; Zhou, Yuan; Yang, Kaiguang; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

2011-03-15

Piperazine-based derivatives, including 1-(2-pyridyl)piperazine (2-PP), 1-(2-pyrimidyl)piperazine (2-PMP), 1-(4-pyridyl)piperazine (4-PP), and 1-(1-methyl-4-piperidinyl)piperazine (M-PP), were used for the derivatization of carboxyl groups on peptides with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC) and 1-hydroxy-7-azabenzotriazole (HOAt) as coupling reagents, and trifluoroacetic acid (TFA) as activator. Taking synthetic peptides RVYVHPI (RI-7) and APGDRIYVHPF (AF-11) as samples, the yields of derivatized peptides by 2-PP, 2-PMP and 4-PP were higher than 94%. The effect of piperazine derivatives on the signals of tryptic digests of α-transferrin and bovine serum albumin (BSA) was investigated, and it was found that peptides derivatized by 2-PP and 2-PMP exhibited obviously improved ionization efficiency. Furthermore, comparison of identified peptides before and after derivatization showed that peptides with low molecular weight (MW) and high pI value were preferably detected after derivatization. In addition, after derivatization with 2-PP and 2-PMP, protein myelin basic protein S, 20 kDa protein, and histone H were confidently identified from the tryptic digests of two fractions of rat brain protein separated by reversed-phase high-performance liquid chromatography (HPLC), indicating the potential application of 2-PP and 2-PMP for the highly sensitive determination of peptides in comprehensive proteome analysis. Copyright © 2011 John Wiley & Sons, Ltd.

Anaerobic Digestion.

PubMed

Liebetrau, Jan; Sträuber, Heike; Kretzschmar, Jörg; Denysenko, Velina; Nelles, Michael

2017-04-09

The term anaerobic digestion usually refers to the microbial conversion of organic material to biogas, which mainly consists of methane and carbon dioxide. The technical application of the naturally-occurring process is used to provide a renewable energy carrier and - as the substrate is often waste material - to reduce the organic matter content of the substrate prior to disposal.Applications can be found in sewage sludge treatment, the treatment of industrial and municipal solid wastes and wastewaters (including landfill gas utilization), and the conversion of agricultural residues and energy crops.For biorefinery concepts, the anaerobic digestion (AD) process is, on the one hand, an option to treat organic residues from other production processes. Concomitant effects are the reduction of organic carbon within the treated substance, the conversion of nitrogen and sulfur components, and the production of an energy-rich gas - the biogas. On the other hand, the multistep conversion of complex organic material offers the possibility of interrupting the conversion chain and locking out intermediates for utilization as basic material within the chemical industry.

Dietary actinidin from kiwifruit (Actinidia deliciosa cv. Hayward) increases gastric digestion and the gastric emptying rate of several dietary proteins in growing rats.

PubMed

Montoya, Carlos A; Hindmarsh, Jason P; Gonzalez, Lucrecia; Boland, Mike J; Moughan, Paul J; Rutherfurd, Shane M

2014-04-01

Dietary actinidin influences the extent to which some dietary proteins are digested in the stomach, and it is hypothesized that the latter modulation will in turn affect their gastric emptying rate (GE). In this study, the effect of dietary actinidin on GE and gastric digestion of 6 dietary protein sources was determined in growing rats. Each dietary protein source [beef muscle, gelatin, gluten, soy protein isolate (SPI), whey protein isolate, and zein] was included in 2 semisynthetic diets as the sole nitrogen source. For each protein source, 1 of the 2 diets contained actinidin [76.5 U/g dry matter (DM)] in the form of ground freeze-dried green kiwifruit (Actinidia deliciosa cv. Hayward), whereas the other diet contained freeze-dried gold kiwifruit (Actinidia chinensis cv. Hort16A), which is devoid of actinidin (3.4 U/g DM). For both diets, dietary kiwifruit represented 20% of the diet on a DM basis. The real-time GE was determined in rats gavaged with a single dose of the diets using magnetic resonance spectroscopy over 150 min (n = 8 per diet). Gastric protein digestion was determined based on the free amino groups in the stomach chyme collected from rats fed the diets (n = 8 per diet) that were later killed. GE differed across the protein sources [e.g., the half gastric emptying time (T(½)) ranged from 157 min for gluten to 266 min for zein] (P < 0.05). Dietary actinidin increased the gastric digestion of beef muscle (0.6-fold), gluten (3.2-fold), and SPI (0.6-fold) and increased the GE of the diets containing beef muscle (43% T(½)) and zein (23% T(½); P < 0.05). There was an inverse correlation between gastric protein digestion and DM retained in the stomach (r = -0.67; P < 0.05). In conclusion, dietary actinidin increased gastric protein digestion and accelerated the GE for several dietary protein sources. GE may be influenced by gastric protein digestion, and dietary actinidin can be used to modulate GE and protein digestion in the stomach of some

Comparative Digestive Physiology

PubMed Central

Karasov, William H.; Douglas, Angela E.

2015-01-01

In vertebrates and invertebrates, morphological and functional features of gastrointestinal (GI) tracts generally reflect food chemistry, such as content of carbohydrates, proteins, fats, and material(s) refractory to rapid digestion (e.g., cellulose). The expression of digestive enzymes and nutrient transporters approximately matches the dietary load of their respective substrates, with relatively modest excess capacity. Mechanisms explaining differences in hydrolase activity between populations and species include gene copy number variations and single-nucleotide polymorphisms. Transcriptional and posttranscriptional adjustments mediate phenotypic changes in the expression of hydrolases and transporters in response to dietary signals. Many species respond to higher food intake by flexibly increasing digestive compartment size. Fermentative processes by symbiotic microorganisms are important for cellulose degradation but are relatively slow, so animals that rely on those processes typically possess special enlarged compartment(s) to maintain a microbiota and other GI structures that slow digesta flow. The taxon richness of the gut microbiota, usually identified by 16S rRNA gene sequencing, is typically an order of magnitude greater in vertebrates than invertebrates, and the interspecific variation in microbial composition is strongly influenced by diet. Many of the nutrient transporters are orthologous across different animal phyla, though functional details may vary (e.g., glucose and amino acid transport with K+ rather than Na+ as a counter ion). Paracellular absorption is important in many birds. Natural toxins are ubiquitous in foods and may influence key features such as digesta transit, enzymatic breakdown, microbial fermentation, and absorption PMID:23720328

Proteome Profiles of Digested Products of Commercial Meat Sources

PubMed Central

Li, Li; Liu, Yuan; Zhou, Guanghong; Xu, Xinglian; Li, Chunbao

2017-01-01

This study was designed to characterize in vitro-digested products of proteins from four commercial meat products, including dry-cured ham, cooked ham, emulsion-type sausage, and dry-cured sausage. The samples were homogenized and incubated with pepsin and trypsin. The digestibility and particle sizes of digested products were measured. Nano-LC–MS/MS was applied to characterize peptides. The results showed the highest digestibility and the lowest particle size in dry-cured ham (P < 0.05), while the opposite was for cooked ham (P < 0.05). Nano-LC–MS/MS analysis revealed that dry-cured ham samples had the greatest number of 750–3,500 Da Mw peptides in pepsin-digested products. In the digested products of cooked ham and emulsion-type sausage, a lot of peptides were matched with soy protein that was added in the formulations. In addition, protein oxidation was also observed in different meat products. Our findings give an insight into nutritional values of different meat products. PMID:28396857

Biogas from mesophilic anaerobic digestion of cow dung using gelatin as additive

NASA Astrophysics Data System (ADS)

Salam, Bodius; Rahman, Md Mizanur; Sikder, Md Asif R.; Islam, Majedul

2017-06-01

A research work was conducted to investigate the enhanced production ability of biogas from mesophilic anaerobic digestions of cow dung (CD) using gelatin as additive. Five laboratory scale digesters were constructed to digest cow dung, where one set up was used for digestion of cow dung without additive and the other set up were used for digestion with additive. Gelatin additive was added in the slurry of amount 0.29, 0,57, 0.85 and 1.14% (wt.). The digesters were made of glass conical flask of 1-liter capacity each. Cow dung was used 335 gm and water was used 365 gm in each experiment. In the slurry, total solid content was maintained 8% (wt.) for all the observations. The digesters were fed on batch basis. The digesters were operated at ambient temperatures of 26 - 35°C. The total gas yield was obtained about 14.4 L/kg CD for digestion without additive and about 65% more biogas for digestion with 0.29% gelatin additive. The retention time for digestion without additive was 38 days and with additive retention time varied between 24 and 52 days.

Redundancy in Anaerobic Digestion Microbiomes during Disturbances by the Antibiotic Monensin

PubMed Central

Spirito, Catherine M.; Daly, Sarah E.; Werner, Jeffrey J.

2018-01-01

ABSTRACT The antibiotic monensin is fed to dairy cows to increase milk production efficiency. A fraction of this monensin is excreted into the cow manure. Previous studies have found that cow manure containing monensin can negatively impact the performance of anaerobic digesters, especially upon first introduction. Few studies have examined whether the anaerobic digester microbiome can adapt to monensin during the operating time. Here, we conducted a long-term time series study of four lab-scale anaerobic digesters fed with cow manure. We examined changes in both the microbiome composition and function of the anaerobic digesters when subjected to the dairy antibiotic monensin. In our digesters, monensin was not rapidly degraded under anaerobic conditions. The two anaerobic digesters that were subjected to manure from monensin feed-dosed cows exhibited relatively small changes in microbiome composition and function due to relatively low monensin concentrations. At higher concentrations of monensin, which we dosed directly to control manure (from dairy cows without monensin), we observed major changes in the microbiome composition and function of two anaerobic digesters. A rapid introduction of monensin to one of these anaerobic digesters led to the impairment of methane production. Conversely, more gradual additions of the same concentrations of monensin to the other anaerobic digester led to the adaptation of the anaerobic digester microbiomes to the relatively high monensin concentrations. A member of the candidate OP11 (Microgenomates) phylum arose in this anaerobic digester and appeared to be redundant with certain Bacteroidetes phylum members, which previously were dominating. IMPORTANCE Monensin is a common antibiotic given to dairy cows in the United States and is partly excreted with dairy manure. An improved understanding of how monensin affects the anaerobic digester microbiome composition and function is important to prevent process failure for farm

VALIDATION FOR THE PERMANGANATE DIGESTION OF REILLEX HPQ ANION RESIN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kyser, E.

2009-09-23

The flowsheet for the digestion of Reillex{trademark} HPQ was validated both under the traditional alkaline conditions and under strongly acidic conditions. Due to difficulty in performing a pH adjustment in the large tank where this flowsheet must be performed, the recommended digestion conditions were changed from pH 8-10 to 8 M HNO{sub 3}. Thus, no pH adjustment of the solution is required prior to performing the permanganate addition and digestion and the need to sample the digestion tank to confirm appropriate pH range for digestion may be avoided. Neutralization of the acidic digestion solution will be performed after completion ofmore » the resin digestion cycle. The amount of permanganate required for this type of resin (Reillex{trademark} HPQ) was increased from 1 kg/L resin to 4 kg/L resin to reduce the amount of residual resin solids to a minimal amount (<5%). The length of digestion time at 70 C remains unchanged at 15 hours. These parameters are not optimized but are expected to be adequate for the conditions. The flowsheet generates a significant amount of fine manganese dioxide (MnO{sub 2}) solids (1.71 kg/L resin) and involves the generation of a significant liquid volume due to the low solubility of permanganate. However, since only two batches of resin (40 L each) are expected to be digested, the total waste generated is limited.« less

Digested wheat gluten inhibits binding between leptin and its receptor.

PubMed

Jönsson, Tommy; Memon, Ashfaque A; Sundquist, Kristina; Sundquist, Jan; Olsson, Stefan; Nalla, Amarnadh; Bauer, Mikael; Linse, Sara

2015-01-20

Leptin resistance is considered a primary risk factor for obesity. It has been hypothesized that dietary cereal grain protein could cause leptin resistance by preventing leptin from binding to its receptor. Non-degraded dietary wheat protein has been found in human serum at a mean level of 41 ng/mL. Here, we report our findings from testing whether enzymatically digested gluten from wheat prevents leptin from binding to the leptin receptor in vitro. Gluten from wheat was digested with pepsin and trypsin under physiological conditions. Pepsin and trypsin activity was removed from the gluten digest with a 10 kDa spin-filter or by heat treatment at 100°C for 30 min. Binding to the leptin receptor of leptin mixed with gluten digest at a series of concentrations was measured using surface plasmon resonance technology. Binding of the gluten digest to the leptin receptor was not detected. Spin-filtered gluten digest inhibited binding of leptin to the leptin receptor, with 50% inhibition at a gluten digest concentration of ~10 ng/mL. Heat-treated gluten digest did not inhibit leptin binding. Digested wheat gluten inhibits binding of leptin to the leptin receptor, with half-maximal inhibition at 10 ng/mL. The inhibition is significant at clinically relevant concentrations and could therefore serve as a novel pathway to investigate to understand the molecular basis of leptin resistance, obesity and associated disorders.

Digestive system development and study of acid and alkaline protease digestive capacities using biochemical and molecular approaches in totoaba (Totoaba macdonaldi) larvae.

PubMed

Galaviz, Mario A; López, Lus M; García Gasca, Alejandra; Álvarez González, Carlos Alfonso; True, Conal D; Gisbert, Enric

2015-10-01

The present study aimed to describe and understand the development of the digestive system in totoaba (Totoaba macdonaldi) larvae from hatching to 40 days post-hatch (dph) from morphological and functional perspectives. At hatch, the digestive system of totoaba was undifferentiated. The anus and the mouth opened at 4 and 5 dph, respectively. During exogenous feeding, development of the esophagus, pancreas, liver and intestine was observed with a complete differentiation of all digestive organs. Expression and activity of trypsin and chymotrypsin were observed as early as at 1 dph, and increments in their expression and activity coincided with changes in food items (live and compound diets) and morpho-physiological development of the accessory digestive glands. In contrast, pepsin was detected later during development, which includes the appearance of the gastric glands between 24 and 28 dph. One peak in gene expression was detected at 16 dph, few days before the initial development of the stomach at 20 dph. A second peak of pepsin expression was detected at day 35, followed by a peak of activity at day 40, coinciding with the change from live to artificial food. Totoaba larvae showed a fully morphologically developed digestive system between 24 and 28 dph, as demonstrated by histological observations. However, gene expression and activity of alkaline and acid proteases were detected earlier, indicating the functionality of the exocrine pancreas and stomach before the complete morphological development of the digestive organs. These results showed that integrative studies are needed to fully understand the development of the digestive system from a morphological and functional point of views, since the histological organization of digestive structures does not reflect their real functionality. These results indicate that the digestive system of totoaba develops rapidly during the first days post-hatch, especially for alkaline proteases, and the stomach

Anaerobic digestibility of beef hooves with swine manure or slaughterhouse sludge.

PubMed

Xia, Yun; Wang, Ding-Kang; Kong, Yunhong; Ungerfeld, Emilio M; Seviour, Robert; Massé, Daniel I

2015-04-01

Anaerobic digestion is an effective method for treating animal by-products, generating at the same time green energy as methane (CH4). However, the methods and mechanisms involved in anaerobic digestion of α-keratin wastes like hair, nails, horns and hooves are still not clear. In this study we investigated the feasibility of anaerobically co-digesting ground beef hooves in the presence of swine manure or slaughterhouse sludge at 25 °C using eight 42-L Plexiglas lab-scale digesters. Our results showed addition of beef hooves statistically significantly increased the rate of CH4 production with swine manure, but only increased it slightly with slaughterhouse sludge. After 90-day digestion, 73% of beef hoof material added to the swine manure-inoculated digesters had been converted into CH4, which was significantly higher than the 45% level achieved in the slaughterhouse sludge inoculated digesters. BODIPY-Fluorescent casein staining detected proteolytic bacteria in all digesters with and without added beef hooves, and their relative abundances corresponded to the rate of methanogenesis of the digesters with the different inocula. Fluorescence in situ hybridization in combination with BODIPY-Fluorescent casein staining identified most proteolytic bacteria as members of genus Alkaliphilus in the subfamily Clostridiaceae 2 of family Clostridiaceae. They thus appear to be the bacteria mainly responsible for digestion of beef hooves. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Auditory Processing Disorders: An Overview. ERIC Digest.

ERIC Educational Resources Information Center

Ciocci, Sandra R.

This digest presents an overview of children with auditory processing disorders (APDs), children who can typically hear information but have difficulty attending to, storing, locating, retrieving, and/or clarifying that information to make it useful for academic and social purposes. The digest begins by describing central auditory processing and…

Crystallization and preliminary X-ray diffraction analysis of the amidase domain of allophanate hydrolase from Pseudomonas sp. strain ADP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Balotra, Sahil; Newman, Janet; French, Nigel G.

2014-02-19

The amidase domain of the allophanate hydrolase AtzF from Pseudomonas sp. strain ADP has been crystallized and preliminary X-ray diffraction data have been collected. The allophanate hydrolase from Pseudomonas sp. strain ADP was expressed and purified, and a tryptic digest fragment was subsequently identified, expressed and purified. This 50 kDa construct retained amidase activity and was crystallized. The crystals diffracted to 2.5 Å resolution and adopted space group P2{sub 1}, with unit-cell parameters a = 82.4, b = 179.2, c = 112.6 Å, β = 106.6°.

Capillary electrophoresis-MALDI interface based on inkjet technology

PubMed Central

Vannatta, Michael W.; Whitmore, Colin D.; Dovichi, Norman J.

2010-01-01

An ink jet printer valve and nozzle were used to deliver matrix and sample from an electrophoresis capillary onto a MALDI plate. The system was evaluated by separation of a set of standard peptides. That separation generated up to 40,000 theoretical plates in less than three minutes. Detection limits were 500 amol using an ABI TOF-TOF instrument and 2 fmol for an ABI Q-TOF instrument. Over 70% coverage was obtained for the tryptic digest of α-lactalbumin in less than 2.5 minutes. PMID:19960472

Discovery of a novel protein modification: alpha-glycerophosphate is a substituent of meningococcal pilin.

PubMed Central

Stimson, E; Virji, M; Barker, S; Panico, M; Blench, I; Saunders, J; Payne, G; Moxon, E R; Dell, A; Morris, H R

1996-01-01

Pili, which are filamentous protein structures on the surface of the meningitis-causing organism Neisseria meningitidis, are known to be post-translationally modified with substituents that affect their mobility in SDS/PAGE and which might play a crucial role in adherence and bloodstream invasion. Tryptic digests of pili were analysed by fast atom bombardment and electrospray MS to identify putative modifications. Serine-93 was found to carry a novel modification of alpha-glycerophosphate. This is the first time that alpha-glycerophosphate has been observed as a substituent of a prokaryotic or eukaryotic protein. PMID:8645220

Anaerobic co-digestion of pig manure and algae: impact of intracellular algal products recovery on co-digestion performance.

PubMed

Astals, S; Musenze, R S; Bai, X; Tannock, S; Tait, S; Pratt, S; Jensen, P D

2015-04-01

This paper investigates anaerobic co-digestion of pig manure and algae (Scenedesmus sp.) with and without extraction of intracellular algal co-products, with views towards the development of a biorefinery concept for lipid, protein and/or biogas production. Protein and/or lipids were extracted from Scenedesmus sp. using free nitrous acid pre-treatments and solvent-based Soxhlet extraction, respectively. Processing increased algae methane yield between 29% and 37% compared to raw algae (VS basis), but reduced the amount of algae available for digestion. Co-digestion experiments showed a synergy between pig manure and raw algae that increased raw algae methane yield from 0.163 to 0.245 m(3) CH4 kg(-1)VS. No such synergy was observed when algal residues were co-digested with pig manure. Finally, experimental results were used to develop a high-level concept for an integrated biorefinery processing pig manure and onsite cultivated algae, evaluating methane production and co-product recovery per mass of pig manure entering the refinery. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dynamic gastric digestion of a commercial whey protein concentrate†.

PubMed

Miralles, Beatriz; Del Barrio, Roberto; Cueva, Carolina; Recio, Isidra; Amigo, Lourdes

2018-03-01

A dynamic gastrointestinal simulator, simgi ® , has been applied to assess the gastric digestion of a whey protein concentrate. Samples collected from the outlet of the stomach have been compared to those resulting from the static digestion protocol INFOGEST developed on the basis of physiologically inferred conditions. Progress of digestion was followed by SDS-PAGE and LC-MS/MS. By SDS-PAGE, serum albumin and α-lactalbumin were no longer detectable at 30 and 60 min, respectively. On the contrary, β-lactoglobulin was visible up to 120 min, although in decreasing concentrations in the dynamic model due to the gastric emptying and the addition of gastric fluids. Moreover, β-lactoglobulin was partly hydrolysed by pepsin probably due to the presence of heat-denatured forms and the peptides released using both digestion models were similar. Under dynamic conditions, a stepwise increase in number of peptides over time was observed, while the static protocol generated a high number of peptides from the beginning of digestion. Whey protein digestion products using a dynamic stomach are consistent with those generated with the static protocol but the kinetic behaviour of the peptide profile emphasises the effect of the sequential pepsin addition, peristaltic shaking, and gastric emptying on protein digestibility. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

Co-digestion of pig slaughterhouse waste with sewage sludge.

PubMed

Borowski, Sebastian; Kubacki, Przemysław

2015-06-01

Slaughterhouse wastes (SHW) are potentially very attractive substrates for biogas production. However, mono-digestion of these wastes creates great technological problems associated with the inhibitory effects of ammonia and fatty acids on methanogens as well as with the foaming in the digesters. In the following study, the co-digestion of slaughterhouse wastes with sewage sludge (SS) was undertaken. Batch and semi-continuous experiments were performed at 35°C with municipal sewage sludge and pig SHW composed of meat tissue, intestines, bristles and post-flotation sludge. In batch assays, meat tissue and intestinal wastes gave the highest methane productions of 976 and 826 dm(3)/kg VS, respectively, whereas the methane yield from the sludge was only 370 dm(3)/kg VS. The co-digestion of sewage sludge with 50% SHW (weight basis) provided the methane yield exceeding 600 dm(3)/kg VS, which was more than twice as high as the methane production from sewage sludge alone. However, when the loading rate exceeded 4 kg VS/m(3) d, a slight inhibition of methanogenesis was observed, without affecting the digester stability. The experiments showed that the co-digestion of sewage sludge with large amount of slaughterhouse wastes is feasible, and the enhanced methane production does not affect the digester stability. Copyright © 2015 Elsevier Ltd. All rights reserved.

Digestive capacity predicts diet diversity in Neotropical frugivorous bats.

PubMed

Saldaña-Vázquez, Romeo A; Ruiz-Sanchez, Eduardo; Herrera-Alsina, Leonel; Schondube, Jorge E

2015-09-01

1. Predicting the diet diversity of animals is important to basic and applied ecology. Knowledge of diet diversity in animals helps us understand niche partitioning, functional diversity and ecosystem services such as pollination, pest control and seed dispersal. 2. There is a negative relationship between the length of the digestive tract and diet diversity in animals; however, the role of digestive physiology in determining diet diversity has been ignored. This is especially important in vertebrates with powered flight because, unlike non-flying vertebrates, they have limitations that may constrain gut size. 3. Here, we evaluate the relationship between digestive capacity and diet diversity in Carollinae and Stenodermatinae frugivorous bats. These bats disperse the seeds of plants that are key to Neotropical forest regeneration. 4. Our results show that digestive capacity is a good predictor of diet diversity in Carollinae and Stenodermatinae frugivorous bats (R(2) = 0·77). 5. Surprisingly, the most phylogenetically closely related species were not similar in their digestive capacity or diet diversity. The lack of a phylogenetic signal for the traits evaluated implies differences in digestive physiology and diet in closely related species. 6. Our results highlight the predictive usefulness of digestive physiology for understanding the feeding ecology of animals. © 2015 The Authors. Journal of Animal Ecology © 2015 British Ecological Society.

Determination of gold and silver in geological samples by focused infrared digestion: A re-investigation of aqua regia digestion.

PubMed

Wang, Yong; Baker, Laura A; Brindle, Ian D

2016-02-01

Focused infrared radiation-based digestions, for the determination of gold and silver, can be achieved in a timeframe as short as 10-15 min, making it an attractive candidate technology for the mining industry, where very large numbers of samples are analyzed on a daily basis. An investigation was carried out into gold and silver dissolution chemistry from geological samples using this novel digestion technique. This study investigated in-depth the issue of low recoveries of gold from aqua regia (AR) digestions, reported by a number of researchers. Conventional AR digestions consistently delivered gold recoveries in a range of 69-80% of the certified values for the four certified reference materials (CRM) employed (CCU-1d, SN26, OREAS 62c, and AMiS 0274), while silver recoveries were satisfactory. By gradually shifting the HCl:HNO3 ratio (v/v) from 3:1 to a reversed 1:3 ratio, recoveries of gold and silver exhibited inverse trends. At a HCl:HNO3 ratio of 1:3, complete recovery of gold was achieved with excellent reproducibility in all CRMs. Meanwhile, silver recoveries plunged significantly at this ratio in samples with higher silver concentrations. Silver values were recovered, however, when the silver was re-solubilized by adding a small volume of concentrated HCl to the cooled reverse aqua regia digests. Recoveries of base metals, such as Fe and Cu, were satisfactory throughout and were much less sensitive to changes in the digestion medium. Using four CRMs and five real-world gold/silver containing samples, the utility of the proposed reverse aqua regia was systematically studied. The uncomplicated nature of the digestion methods reported here, that are fast, effective and inexpensive, may be useful to analysts developing/optimizing their methods for the rapid determination of Au and Ag in a variety of mineral phases, particularly where rapid results are desirable, such as in prospecting and mine development. Copyright © 2015 Elsevier B.V. All rights reserved.

[Digestive and extra-digestive complications of nonsteroidal anti-inflammatory drugs. Preventive and curative strategies].

PubMed

Sternon, J; Adler, M

1997-04-01

The authors review the digestive ulceration risk factors and the criteria for selecting a non steroidal antiinflammatory (NSAI), included the most recent drugs, such as selective anti-cyclo-oxygenases 2. They actualize the preventive strategies and insist on the values of misoprostol and of slow acting anti-rheumatic drugs. In the case of digestive ulcerations, they plead for the immediate stop of the NSAI and its replacement if necessary by corticosteroids, for the prescription of a proton pump inhibitor (PPI) or mesalazine according to the localisation of the lesion, finally for the eradication within 8 days of Helicobacter pylori.

In vitro versus in vivo protein digestibility techniques for calculating PDCAAS (protein digestibility-corrected amino acid score) applied to chickpea fractions.

PubMed

Tavano, Olga Luisa; Neves, Valdir Augusto; da Silva Júnior, Sinézio Inácio

2016-11-01

Seven different in vitro methods to determine the protein digestibility for chickpea proteins were considered and also the application of these methodologies for calculating PDCAAS (protein digestibility-corrected amino acid score), seeking their correlations with the in vivo methodology. In vitro digestibility of raw and heated samples were determined using pepsin-pancreatin hydrolysis, considering soluble nitrogen via Kjeldahl (ppKJ) and hydrolysed peptide linkages using trinitrobenzenesulfonic acid and o-phthaldialdehyde. In vitro digestibility was also determined using trypsin, chymotrypsin and peptidase (3-Enz) or trypsin, chymotrypsin, peptidase and pronase solution (4-Enz). None of the correlations between in vitro and in vivo digestibilities were significant (at p<0.0500), but, strong correlations were observed between PDCAAS calculated by in vitro and in vivo results. PDCAAS-ppKJ, PDCAAS-3-Enz and PDCAAS-4-Enz presented the highest correlations with in vivo method, r=0.9316, 0.9442 and 0.9649 (p<0.0500), respectively. The use of in vitro methods for calculating PDCAAS may be promising and deserves more discussions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Anaerobic co-digestion of cyanide containing cassava pulp with pig manure.

PubMed

Glanpracha, Naraporn; Annachhatre, Ajit P

2016-08-01

Anaerobic co-digestion of cyanide-containing cassava pulp with pig manure was evaluated using laboratory scale mesophilic digester. The digester was operated in a semi-continuous mode with the mixed feedstock having C/N ratio of 35:1. Digester startup was accomplished in 60days with loading of 0.5-1kgVS/m(3)d. Subsequently, the loading to digester was increased step-wise from 2 to 9kgVS/m(3)d. Digester performance was stable at loading between 2 and 6kgVS/m(3)d with an average volatile solid removal and methane yield of 82% and 0.38m(3)/kgVSadded, respectively. However, beyond loading of 7kgVS/m(3)d, solubilization of particulate matter did not take place efficiently. Cyanide present in cassava pulp was successfully degraded indicating that anaerobic sludge in the digester was well acclimatized to cyanide. The results show that cassava pulp can be successfully digested anaerobically with pig manure as co-substrate without any inhibitory effect of cyanide present in the cassava pulp. Copyright © 2016 Elsevier Ltd. All rights reserved.

Antioxidant activity in cooked and simulated digested eggs.

PubMed

Remanan, M K; Wu, J

2014-07-25

The avian egg is an excellent source of nutrients consisting of components with beneficial properties but there is limited knowledge on the effect of cooking methods and gastrointestinal digestion on the antioxidant activity of eggs. The present study was focused on the effect of cooking and simulated gastrointestinal digestion on antioxidant activity of eggs using ORAC, ABTS and DPPH assays. The results suggest that fresh egg yolk has higher antioxidant activity than fresh egg white and whole eggs. Cooking reduced whereas simulated gastrointestinal digestion increased the antioxidant activity of eggs. Boiled egg white hydrolysate showed the highest antioxidant activity; a total of 63 peptides were identified, indicative of the formation of novel antioxidant peptides upon simulated gastrointestinal digestion. This study suggests the potential role of eggs as a dietary source of antioxidants.

University of Wisconsin Oshkosh Anaerobic Dry Digestion Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Koker, John; Lizotte, Michael

The University of Wisconsin Oshkosh Anaerobic Dry Digestion Facility is a demonstration project that supported the first commercial-scale use in the United States of high solids, static pile technology for anaerobic digestion of organic waste to generate biogas for use in generating electricity and heat. The research adds to the understanding of startup, operation and supply chain issues for anaerobic digester technology. Issues and performance were documented for equipment installation and modifications, feedstock availability and quality, weekly loading and unloading of digestion chambers, chemical composition of biogas produced, and energy production. This facility also demonstrated an urban industrial ecology approachmore » to siting such facilities near sewage treatment plants (to capture and use excess biogas generated by the plants) and organic yard waste collection sites (a source of feedstock).« less

Digestive recovery of sulfur-methyl-L-methionine and its bioaccessibility in Kimchi cabbages using a simulated in vitro digestion model system.

PubMed

Lee, Hae-Rim; Cho, Sun-Duk; Lee, Woon Kyu; Kim, Gun-Hee; Shim, Soon-Mi

2014-01-15

Sulfur-methyl-L-methionine (SMM) has been known to provide various biological functions such as radical scavenging effect, inhibition of adipocyte differentiation, and prevention of gastric mucosal damage. Kimchi cabbages are known to be a major food source providing SMM but its bioaccessibility has not been studied. The objective of current study was to determine both the digestive stability of SMM and the amount released from Kimchi cabbages under a simulated in vitro digestion model system. The in vitro digestion model system simulating a human gastrointestinal tract was carried out for measuring digestive recovery and bioaccessibility of SMM. SMM was quantified by using high-performance liquid chromatography with a fluorescence detector. Recovery of an SMM standard after digestion was 0.68 and 0.65% for fasted and fed conditions, respectively, indicating that the digestive stability of the SMM standard was not affected by dietary energy or co-ingested food matrix. The SMM standard was also significantly stable in acidic pH (P < 0.05). The bioaccessibility of SMM from Kimchi cabbages was measured under a fasted condition, resulted in 8.83, 14.71 and 10.88%, for salivary, gastric and small intestinal phases, respectively. Results from our study suggest that SMM from Kimchi cabbages, a component of food sources, is more bioavailable than SMM by itself. © 2013 Society of Chemical Industry.

Measurement of protein digestibility in humans by a dual-tracer method.

PubMed

Devi, Sarita; Varkey, Aneesia; Sheshshayee, M S; Preston, Thomas; Kurpad, Anura V

2018-06-01

Recent evaluations of the risk of dietary protein deficiency have indicated that protein digestibility may be a key limiting factor in the provision of indispensable amino acids (IAAs), particularly for vulnerable populations living in challenging environments where intestinal dysfunction may exist. Since the digestion of protein occurs only in the small intestine, and the metabolic activity of colonic bacteria confounds measurements at the fecal level, there is a need to develop noninvasive protein digestibility measurements at the ileal level. We used a dual-tracer method with stable isotopes to characterize the digestibility of uniformly labeled [13C]-spirulina protein as a standard protein, in comparison to a mixture of 2H-labeled crystalline amino acids, and then demonstrated the use of this standard protein to measure the digestibility of selected legumes (chick pea and mung bean) through the use of proteins that were intrinsically labeled with 2H. The digestibility of uniformly labeled [13C]-spirulina was first measured in 6 healthy volunteers (3 males and 3 females) by feeding it along with a standard mixture of 2H-labeled amino acids, in a dual-tracer, plateau-fed test meal approach. Next, intrinsically labeled legume protein digestibility was studied with a similar dual-tracer approach, with uniformly labeled [13C]-spirulina as the standard, when processed differently before consumption. The average digestibility of IAA in spirulina protein was 85.2%. The average IAA digestibility of intrinsically 2H-labeled chick pea and mung bean protein was 56.6% and 57.7%, respectively. Dehulling of mung bean before ingestion increased the average IAA digestibility by 9.9% in comparison to whole mung bean digestibility. An innovative, minimally invasive "dual-stable-isotope" method was developed to measure protein digestibility, in which the ingestion of an intrinsically 2H-labeled test protein along with a 13C-labeled standard protein of known digestibility allows

Comparison between ozone and ultrasound disintegration on sludge anaerobic digestion.

PubMed

Braguglia, C M; Gianico, A; Mininni, G

2012-03-01

This paper deals with the comparison of ultrasound (mechanical) and ozone (chemical) pre-treatment on the performances of excess sludge semi-continuous digestion. Sludge solubilisation has been investigated by varying specific energy input. For each pre-treatment, long anaerobic digestion tests were carried out by two parallel digesters: one reactor, as control unit, was fed with untreated waste activated sludge, and the other one was fed with disintegrated sludge. To evaluate and compare the efficacy of both pre-treatments, the specific energy was maintained approximately the same. The digestion tests were carried out to investigate the feasibility of anaerobic digestion performance (total biogas production, volatile solids removal, sludge dewaterability) and to assess the heat balance. Results obtained from the digestion of sonicated sludge at 4% disintegration degree (≈ 2500 kJ/kg TS) showed that the ultrasound pre-treatment may be effective both in increasing VS destruction (+19%) and cumulative biogas production (+26%). On the contrary, the digestion test with ozonized sludge (ozone dose of 0.05 g O(3)/g TS corresponding to ≈ 2000 kJ/kg TS) did not indicate a significant improvement on the digestion performances. By doubling the ozone dose an improvement in the organics removal and cumulative biogas production was observed. Relevant differences in terms of colloidal charge and filterability were discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Application of microwave digestion to the analysis of peat

USGS Publications Warehouse

Papp, C.S.E.; Fischer, L.B.

1987-01-01

A microwave digestion technique for the dissolution of peat is described and compared with a dry ashing method and a nitric - perchloric - hydrofluoric acid wet digestion. Peat samples with different organic matter contents were used and Ca, Mg, Fe, AI, Na, K, Mn, Zn, Cu and Li were determined by atomic absoprtion spectrometry. The results obtained using the three dissolution techniques were in good agreement. The microwave method has the advantage of digesting the samples in less than 2 h and uses less acid than the conventional wet digestion method. Keeping the volume of the acid mixture as small as possible minimises contamination and leads to lower blank values.

Online Resources for Teaching Shakespeare. ERIC Digest.

ERIC Educational Resources Information Center

Stoicheva, Mila

To assist educators in effectively teaching the works of such a critical author as William Shakespeare, this Digest identifies and describes some of the most significant and useful online resources. The digest notes that the sites were chosen on the basis of their technical excellence, purpose, content, authorship, and general usefulness for…

Video Games: Research, Ratings, Recommendations. ERIC Digest.

ERIC Educational Resources Information Center

Cesarone, Bernard

This Digest reviews research on the demographics and effects of video game playing, discusses game rating systems, and offers recommendations for parents. The Digest begins by discussing research on the time children spend playing electronic games, which shows that younger children's game playing at home (90% of fourth-graders played at least one…

La Disciplina Positiva (Positive Discipline). ERIC Digest.

ERIC Educational Resources Information Center

ERIC Clearinghouse on Elementary and Early Childhood Education, Urbana, IL.

This ERIC Digest suggests methods and language that can be used in handling difficult, but common, situations involving young children. The digest explains 12 methods of disciplining children that promote children's self-worth. These methods are: (1) showing children that the reasons for their actions are understood; (2) stating reasons; (3)…

Flexible digestion strategies and trace metal assimilation in marine bivalves

USGS Publications Warehouse

Decho, Alan W.; Luoma, Samuel N.

1996-01-01

Pulse-chase experiments show that two marine bivalves take optimal advantage of different types of particulate food by varying food retention time in a flexible two-phase digestive system. For example, carbon is efficiently assimilated from bacteria by subjecting nearly all the ingested bacteria to prolonged digestion. Prolonging digestion also enhances assimilation of metals, many of which are toxic in minute quantities if they are biologically available. Detritus-feeding aquatic organisms have always lived in environments naturally rich in particle-reactive metals. We suggest that avoiding excess assimilation of metals could be a factor in the evolution of digestion strategies. We tested that suggestion by studying digestion of particles containing different Cr concentrations. We show that bivalves are capable of modifying the digestive processing of food to reduce exposure to high, biologically available, Cr concentrations. The evolution of a mechanism in some species to avoid high concentrations of metals in food could influence how effects of modern metal pollution are manifested in marine ecosystems.

Physicochemical properties and starch digestibility of whole grain sorghums, millet, quinoa and amaranth flours, as affected by starch and non-starch constituents.

PubMed

Srichuwong, Sathaporn; Curti, Delphine; Austin, Sean; King, Roberto; Lamothe, Lisa; Gloria-Hernandez, Hugo

2017-10-15

Minor grains such as sorghum, millet, quinoa and amaranth can be alternatives to wheat and corn as ingredients for whole grain and gluten-free products. In this study, influences of starch structures and other grain constituents on physicochemical properties and starch digestibility of whole flours made from these grains were investigated. Starches were classified into two groups according to their amylopectin branch chain-length: (i) quinoa, amaranth, wheat (shorter chains); and (ii) sorghum, millet, corn (longer chains). Such amylopectin features and amylose content contributed to the differences in thermal and pasting properties as well as starch digestibility of the flours. Non-starch constituents had additional impacts; proteins delayed starch gelatinization and pasting, especially in sorghum flours, and high levels of soluble fibre retarded starch retrogradation in wheat, quinoa and amaranth flours. Enzymatic hydrolysis of starch was restricted by the presence of associated protein matrix and enzyme inhibitors, but accelerated by endogenous amylolytic enzymes. Copyright © 2017 Elsevier Ltd. All rights reserved.

A novel methodology for rapid digestion of rare earth element ores and determination by microwave plasma-atomic emission spectrometry and dynamic reaction cell-inductively coupled plasma-mass spectrometry.

PubMed

Helmeczi, Erick; Wang, Yong; Brindle, Ian D

2016-11-01

Short-wavelength infrared radiation has been successfully applied to accelerate the acid digestion of refractory rare-earth ore samples. Determinations were achieved with microwave plasma-atomic emission spectrometry (MP-AES) and dynamic reaction cell - inductively coupled plasma-mass spectrometry (DRC-ICP-MS). The digestion method developed was able to tackle high iron-oxide and silicate matrices using only phosphoric acid in a time frame of only 8min, and did not require perchloric or hydrofluoric acid. Additionally, excellent recoveries and reproducibilities of the rare earth elements, as well as uranium and thorium, were achieved. Digestions of the certified reference materials OREAS-465 and REE-1, with radically different mineralogies, delivered results that mirror those obtained by fusion processes. For the rare-earth CRM OKA-2, whose REE data are provisional, experimental data for the rare-earth elements were generally higher than the provisional values, often exceeding z-values of +2. Determined values for Th and U in this reference material, for which certified values are available, were in excellent agreement. Copyright © 2016 Elsevier B.V. All rights reserved.

Environmental biomonitoring of essential and toxic elements in human scalp hair using accelerated microwave-assisted sample digestion and inductively coupled plasma optical emission spectroscopy.

PubMed

Kumakli, Hope; Duncan, A'ja V; McDaniel, Kiara; Mehari, Tsdale F; Stephenson, Jamira; Maple, Lareisha; Crawford, Zaria; Macemore, Calvin L; Babyak, Carol M; Fakayode, Sayo O

2017-05-01

Human scalp hair samples were collected and used to assess exposure to toxic elements and essential elements in the state of North Carolina, USA using accelerated microwave assisted acid digestion and inductively coupled plasma optical emission spectroscopy (ICP-OES). The figures-of-merit of the ICP-OES were appropriate for elemental analysis in scalp hair with detection limits as low as 0.0001 mg/L for Cd, good linearity (R 2  > 0.9978), and percent recoveries that ranged from 96 to 106% for laboratory-fortified-blanks and 88-112% for sample spike recovery study. The concentrations of essential elements in scalp hair were larger than those of toxic elements, with Ca having the highest average concentration (3080 μg/g, s = 14,500, n = 194). Some of the maximum concentrations observed for As (65 μg/g), Ni (331 μg/g), Cd (2.96 μg/g), and Cr (84.6 μg/g) in individual samples were concerning, however. Samples were statistically analyzed to determine the influence of race, gender, smoking habits, or age on the elemental concentrations in scalp hair. Higher concentrations of essential elements were observed in the scalp hair of Caucasians, females, and non-smokers, and the differences were often significant at a 90% confidence level. Several pairs of essential elements, for example Ca-K, Ca-Mg, and Ca-Zn, were strongly correlated in Caucasian hair but uncorrelated in African-American hair. Similarly, essential elements were strongly correlated in female hair but weakly correlated in male hair. Toxic element pairs (As-Cd, As-Se, Pb-As, and Se-Cd) were strongly correlated in the hair of smokers but uncorrelated in that of non-smokers, suggesting that cigarette smoke is a common source of toxic elements in humans. Published by Elsevier Ltd.

Anaerobic digestion potential of urban organic waste: a case study in Malmö.

PubMed

Davidsson, Asa; Jansen, Jes la Cour; Appelqvist, Björn; Gruvberger, Christopher; Hallmer, Martin

2007-04-01

A study of existing organic waste types in Malmö, Sweden was performed. The purpose was to gather information about organic waste types in the city to be able to estimate the potential for anaerobic treatment in existing digesters at the wastewater treatment plan (WWTP). The urban organic waste types that could have a significant potential for anaerobic digestion amount to about 50 000 tonnes year(-1) (sludge excluded). Some of the waste types were further evaluated by methane potential tests and continuous pilot-scale digestion. Single-substrate digestion and co-digestion of pre-treated, source-sorted organic fraction of municipal solid waste, wastewater sludge, sludge from grease traps and fruit and vegetable waste were carried out. The experiments showed that codigestion of grease sludge and WWTP sludge was a better way of making use of the methane potential in the grease trap sludge than single-substrate digestion. Another way of increasing the methane production in sludge digesters is to add source-sorted organic fraction of municipal solid waste (SSOFMSW). Adding SSOFMSW (20% of the total volatile solids) gave a 10-15% higher yield than could be expected by comparison with separate digestion of sludge respective SSOFMSW. Co-digestion of sludge and organic waste is beneficial not just for increasing gas production but also for stabilizing the digestion process. This was seen when co-digesting fruit and vegetable waste and sludge. When co-digested with sludge, this waste gave a better result than the separate digestion of fruit and vegetable waste. Considering single-substrate digestion, SSOFMSW is the only waste in the study which makes up a sufficient quantity to be suitable as the base substrate in a full-scale digester that is separated from the sludge digestion. The two types of SSOFMSW tested in the pilot-scale digestion were operated successfully at mesophilic temperature. By adding SSOFMSW, grease trap sludge and fruit and vegetables waste to sludge

Carbohydrate digestion in Lutzomyia longipalpis' larvae (Diptera - Psychodidae).

PubMed

Vale, Vladimir F; Moreira, Bruno H; Moraes, Caroline S; Pereira, Marcos H; Genta, Fernando A; Gontijo, Nelder F

2012-10-01

Lutzomyia longipalpis is the principal species of phlebotomine incriminated as vector of Leishmania infantum, the etiological agent of visceral leishmaniasis in the Americas. Despite its importance as vector, almost nothing related to the larval biology, especially about its digestive system has been published. The objective of the present study was to obtain an overview of carbohydrate digestion by the larvae. Taking in account that phlebotomine larvae live in the soil rich in decaying materials and microorganisms we searched principally for enzymes capable to hydrolyze carbohydrates present in this kind of substrate. The principal carbohydrases encountered in the midgut were partially characterized. One of them is a α-amylase present in the anterior midgut. It is probably involved with the digestion of glycogen, the reserve carbohydrate of fungi. Two other especially active enzymes were present in the posterior midgut, a membrane bound α-glucosidase and a membrane bound trehalase. The first, complete the digestion of glycogen and the other probably acts in the digestion of trehalose, a carbohydrate usually encountered in microorganisms undergoing hydric stress. In a screening done with the use of p-nitrophenyl-derived substrates other less active enzymes were also observed in the midgut. A general view of carbohydrate digestion in L. longipalpis was presented. Our results indicate that soil microorganisms appear to be the main source of nutrients for the larvae. Copyright © 2012 Elsevier Ltd. All rights reserved.

Bioelectrochemical enhancement of methane production from highly concentrated food waste in a combined anaerobic digester and microbial electrolysis cell.

PubMed

Park, Jungyu; Lee, Beom; Tian, Donjie; Jun, Hangbae

2018-01-01

A microbial electrolysis cell (MEC) is a promising technology for enhancing biogas production from an anaerobic digestion (AD) reactor. In this study, the effects of the MEC on the rate of methane production from food waste were examined by comparing an AD reactor with an AD reactor combined with a MEC (AD+MEC). The use of the MEC accelerated methane production and stabilization via rapid organic oxidation and rapid methanogenesis. Over the total experimental period, the methane production rate and stabilization time of the AD+MEC reactor were approximately 1.7 and 4.0 times faster than those of the AD reactor. Interestingly however, at the final steady state, the methane yields of both the reactors were similar to the theoretical maximum methane yield. Based on these results, the MEC did not increase the methane yield over the theoretical value, but accelerated methane production and stabilization by bioelectrochemical reactions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Supervision: Exploring the Effective Components. ERIC/CASS Counseling Digest Series.

ERIC Educational Resources Information Center

Borders, L. DiAnne, Ed.

This document contains a collection of ERIC Digests on supervision, a topic of critical professional importance for counselors. Following an introductory article by the guest editor, L. DiAnne Borders, "Supervision: Exploring the Effective Components," 19 digests address a different facet of supervision. The 19 digests are: (1)…

Anaerobic digestion of cattail by rumen cultures.

PubMed

Hu, Zhen-Hu; Yu, Han-Qing

2006-01-01

The anaerobic digestion of aquatic plants could serve the dual roles for producing renewable energy and reducing waste. In this study, the anaerobic digestion of cattail (Typha latifolia linn), a lignocellulosic aquatic plant, by rumen microorganisms in batch cultures was investigated. At a substrate level of 12.4 g/l volatile solids (VS) and pH 6.7, maximum VS conversion of 66% was achieved within an incubation time of 125 h. However, a decrease in pH from 6.7 to 5.8 resulted in a marked reduction in VS conversion. The total volatile fatty acids (VFAs) yield was about 0.56 g/g VS digested. Acetate and propionate were the major aqueous fermentation products, while butyrate, i-butyrate and valerate were also formed in smaller quantities. Biogas that was produced was composed of carbon dioxide, methane and hydrogen. A modified Gompertz equation was developed to describe substrate consumption and product formation. The hydrolysis of insoluble components was the rate-limiting step in the anaerobic digestion of cattail.

Anaerobic digestion of organic solid poultry slaughterhouse waste--a review.

PubMed

Salminen, E; Rintala, J

2002-05-01

This work reviews the potential of anaerobic digestion for material recovery and energy production from poultry slaughtering by-products and wastes. First, we describe and quantify organic solid by-products and wastes produced in poultry farming and poultry slaughterhouses and discuss their recovery and disposal options. Then we review certain fundamental aspects of anaerobic digestion considered important for the digestion of solid slaughterhouse wastes. Finally, we present an overview of the future potential and current experience of the anaerobic digestion treatment of these materials.

Structure and function of the digestive system of solen grandis dunker

NASA Astrophysics Data System (ADS)

Sheng, Xiuzhen; Zhan, Wenbin; Ren, Sulian

2003-10-01

Structure and function of the digestive system of a bivalve mollusc, Solen grandis, were studied using light microscopy and histochemical methods. The wall of digestive tube consists of four layers: the mucosal epithelium, connective tissue, muscular and fibrosa or serosa (only in the portion of rectum) from the inner to the outer. The ciliated columnar epithelial cells, dispersed by cup-shaped mucous cells, rest on a thin base membrane. There are abundant blood spaces in connective tissue layer. The digestive diverticula are composed of multi-branched duct and digestive tubules. The digestive tubules are lined with digestive and basophilic secretory cells, and surrounded by a layer of smooth muscle fibers and connective tissues. Activities of acid and alkaline phosphatases, esterase and lipase are detected in the digestive cells, and the epithelia of stomach and intestine, suggesting that these cells are capable of intracellular digesting of food materials and absorbing. Besides, acid phosphatase and esterase activities are present in the posterior portion of esophagus. Phagocytes are abundant in blood spaces and the lumens of stomach and intestine, containing brown granules derived from the engulfed food materials. The present work indicates that phagocytes play important roles in ingestion and digestion of food materials, which is supported as well by the activities of acid phosphatase, esterase and lipase detected in blood spaces.

Peptide profiling and the bioactivity character of yogurt in the simulated gastrointestinal digestion.

PubMed

Jin, Yan; Yu, Yang; Qi, Yanxia; Wang, Fangjun; Yan, Jiaze; Zou, Hanfa

2016-06-01

This study investigated the relationship between peptide profiles and the bioactivity character of yogurt in simulated gastrointestinal trials. A total of 250, 434 and 466 peptides were identified by LC-MS/MS analyses of yogurt, gastric digest and pancreatic digest. Forty peptides of yogurt survived in gastrointestinal digestion. κ-CN and β-CN contributed the diversity of peptides during the fermentation process and gastrointestinal digestion, respectively. The favorite of κ-CN by lactic acid bacteria complemented gut digestion by hydrolyzing κ-CN, the low abundance milk proteins. The potential bioactivities were evaluated by in vitro ACE and DPP-IV inhibition assays. The ACE inhibition rate of the pancreatic digests was ~4 - and ~2 - fold greater than that of yogurt and the gastric digests. The ACE inhibitory peptides generated during gastrointestinal digestion improved the ACE inhibitory activity of the gastric and pancreatic digests. The DPP-IV inhibition rate of the pancreatic digest was ~6 - and ~3 - fold greater than that of yogurt and the gastric digest. The numbers of potential DPP-IV inhibitory peptides were positively correlated to the DPP-IV inhibitory activity of the gastric and pancreatic digests. The present study describes the characters and bioactivities of peptides from yogurt in a simulated gastrointestinal digestion. The number of peptides identified from yogurt and gastrointestinal digests by LC-MS/MS increased in the simulated gastrointestinal trials. The in vitro ACE and DPP-IV inhibition bioactivities revealed that the bioactivity of yogurt was enhanced during gastrointestinal digestion. The correlation between peptides and bioactivity in vitro indicated that not only the peptides amount but also the proportion of peptides with high bioactivities contributed to increased bioactivity during gastrointestinal digestion. The study of peptides identified from yogurt and digests revealed that the number of released peptides was not determined

Methods of ammonia removal in anaerobic digestion: a review.

PubMed

Krakat, Niclas; Demirel, Burak; Anjum, Reshma; Dietz, Donna

2017-10-01

The anaerobic digestion of substrates with high ammonia content has always been a bottleneck in the methanisation process of biomasses. Since microbial communities in anaerobic digesters are sensitive to free ammonia at certain conditions, the digestion of nitrogen-rich substrates such as livestock wastes may result in inhibition/toxicity eventually leading to process failures, unless appropriate engineering precautions are taken. There are many different options reported in literature to remove ammonia from anaerobic digesters to achieve a safe and stable process so that along with high methane yields, a good quality of effluents can also be obtained. Conventional techniques to remove ammonia include physical/chemical methods, immobilization and adaptation of microorganisms, while novel methods include ultrasonication, microwave, hollow fiber membranes and microbial fuel cell applications. This paper discusses conventional and novel methods of ammonia removal from anaerobic digesters using nitrogen-rich substrates, with particular focus on recent literature available about this topic.

Assessing the potential phytotoxicity of digestate from winery wastes.

PubMed

Da Ros, Cinzia; Libralato, Giovanni; Ghirardini, Annamaria Volpi; Radaelli, Marta; Cavinato, Cristina

2018-04-15

In this study, digestate from winery wastes was investigated focusing on phytotoxicity using macrophytes and evaluating the potential contribution of ammonium and copper. Spreading of digestate on soil could represent a suitable approach to recycle nutrients and organic matter, creating an on site circular economy. In this study, digestate quality was evaluated considering both chemical-physical characteristics and biological toxicity applying germination test. The effluent did not meet the entire amendment quality standard defined by Italian law (Decree 75/2010 germination index > 60% with solution of 30% v/v of digestate), but bio-stimulation was observed at low doses (3.15-6.25% v/v) for S. alba and S. saccharatum. The beneficial concentration agreed with Nitrate Directive dose and suggested that limited addition of digestate could have several positive effects on soil characteristics and on crop growth. Specific test using ammonium and copper solutions showed that these pollutants were not directly correlated to observed phytotoxicity. Copyright © 2017 Elsevier Inc. All rights reserved.

Recovering biomethane and nutrients from anaerobic digestion of water hyacinth (Eichhornia crassipes) and its co-digestion with fruit and vegetable waste.

PubMed

Hernández-Shek, M A; Cadavid-Rodríguez, L S; Bolaños, I V; Agudelo-Henao, A C

2016-01-01

The potential to recover bioenergy from anaerobic digestion of water hyacinth (WH) and from its co-digestion with fruit and vegetable waste (FVW) was investigated. Initially, biogas and methane production were studied using the biochemical methane potential (BMP) test at 2 g volatile solids (VS) L(-1) of substrate concentration, both in the digestion of WH alone and in its co-digestion with FVW (WH-FVW ratio of 70:30). Subsequently, the biogas production was optimized in terms of total solids (TS) concentration, testing 4 and 6% of TS. The BMP test showed a biogas yield of 0.114 m(3) biogas kg(-1) VSadded for WH alone. On the other hand, the biogas potential from the WH-FVW co-digestion was 0.141 m(3) biogas kg(-1) VSadded, showing an increase of 23% compared to that of WH alone. Maximum biogas production of 0.230 m(3) biogas kg(-1) VSadded was obtained at 4% of TS in the co-digestion of WH-FVW. Using semi-continuously stirred tank reactors, 1.3 m(3) biogas yield kg(-1) VSadded was produced using an organic loading rate of 2 kg VS m(-3) d(-1) and hydraulic retention time of 15 days. It was also found that a WH-FVW ratio of 80:20 improved the process in terms of pH stability. Additionally, it was found that nitrogen can be recovered in the liquid effluent with a potential for use as a liquid fertilizer.

Survival rates of parasite eggs in sludge during aerobic and anaerobic digestion.

PubMed Central

Black, M I; Scarpino, P V; O'Donnell, C J; Meyer, K B; Jones, J V; Kaneshiro, E S

1982-01-01

The effects of mesothermic anaerobic or aerobic sludge digestion on survival of eggs from the roundworms Ascaris suum, toxocara canis, Trichuris vulpis, and Trichuris suis and from the rat tapeworm Hymenolepis diminuta were studied. Destruction of eggs throughout a 15-day treatment period, as well as their viabilities after reisolation, was analyzed. The laboratory model digesters used in this study were maintained at a 15-day retention schedule, partially simulating a continuously operating system. Ascaris eggs were destroyed in the anaerobic (23%) or aerobic (38%) digesters, and 11% Trichuris eggs were destroyed in the aerobic digesters. Trichuris eggs in anaerobic digesters and Toxocara eggs in either anaerobic or aerobic digesters were not destroyed. Destruction of eggs in digesters was correlated with the state of the eggs before subjection to the treatment processes; i.e., some Ascaris and Trichuris eggs were already embryonated in host intestinal contents or feces and hence past their most resistant stage. The viabilities of Ascaris and Toxocara eggs that survived the digestion processes were greater in anaerobically treated than in aerobically treated material. Eggs from Hymenolepis were nonviable before use in the experiments. However, they were more effectively destroyed in aerobic digesters than in anaerobic digesters. PMID:6891199

The Writer's Digest Guide to Good Writing.

ERIC Educational Resources Information Center

Clark, Thomas, Ed.; And Others

Marking "Writer's Digest"'s upcoming 75th anniversary, this book presents a collection of the best writing instruction, advice, and inspiration written by famous and not-so-famous writers and published in the magazine from the 1920s to the 1990s. The 49 selections in the book are arranged chronologically and address: (1) selecting an…

Sexism Springs Eternal--in the Reader's Digest.

ERIC Educational Resources Information Center

Zimbardo, Philip G.; Meadow, Wendy

This document reports on an empirical investigation of anti-women humor appearing in the Reader's Digest over three decades, revealing the operation of an unconscious sexist ideology. A systematic analysis was made of 1,069 jokes appearing in two featured columns of the Reader's Digest for the two-year periods 1947-48, 1957-58, and 1967-68.…

Teaching Critical Reading through Literature. ERIC Digest.

ERIC Educational Resources Information Center

Collins, Norma Decker

Noting that it is only within the last decade that schools have begun to identify ways to optimize language use to promote higher level thinking, this ERIC Digest focuses on developing thinking skills in reading. The digest discusses the impetus for critical reading, the use of children's literature as a tool for teaching thinking skills, a…

Motivating Low Performing Adolescent Readers. ERIC Digest.

ERIC Educational Resources Information Center

Collins, Norma Decker

This Digest focuses on motivating the low performing adolescent in a remedial reading or subject area classroom--the idea is that students who are disengaged from their own learning processes are not likely to perform well in school. The Digest points out that such adolescents are often caught in a cycle of failure and that secondary teachers must…

Effect of heat and homogenization on in vitro digestion of milk.

PubMed

Tunick, Michael H; Ren, Daxi X; Van Hekken, Diane L; Bonnaillie, Laetitia; Paul, Moushumi; Kwoczak, Raymond; Tomasula, Peggy M

2016-06-01

Central to commercial fluid milk processing is the use of high temperature, short time (HTST) pasteurization to ensure the safety and quality of milk, and homogenization to prevent creaming of fat-containing milk. Ultra-high-temperature sterilization is also applied to milk and is typically used to extend the shelf life of refrigerated, specialty milk products or to provide shelf-stable milk. The structures of the milk proteins and lipids are affected by processing but little information is available on the effects of the individual processes or sequences of processes on digestibility. In this study, raw whole milk was subjected to homogenization, HTST pasteurization, and homogenization followed by HTST or UHT processing. Raw skim milk was subjected to the same heating regimens. In vitro gastrointestinal digestion using a fasting model was then used to detect the processing-induced changes in the proteins and lipids. Using sodium dodecyl sulfate-PAGE, gastric pepsin digestion of the milk samples showed rapid elimination of the casein and α-lactalbumin bands, persistence of the β-lactoglobulin bands, and appearance of casein and whey peptide bands. The bands for β-lactoglobulin were eliminated within the first 15min of intestinal pancreatin digestion. The remaining proteins and peptides of raw, HTST, and UHT skim samples were digested rapidly within the first 15min of intestinal digestion, but intestinal digestion of raw and HTST pasteurized whole milk showed some persistence of the peptides throughout digestion. The availability of more lipid droplets upon homogenization, with greater surface area available for interaction with the peptides, led to persistence of the smaller peptide bands and thus slower intestinal digestion when followed by HTST pasteurization but not by UHT processing, in which the denatured proteins may be more accessible to the digestive enzymes. Homogenization and heat processing also affected the ζ-potential and free fatty acid release

Modifications in trypsin digestion protocol for increasing the efficiency and coverage.

PubMed

Syal, Kirtimaan; Tadala, Raghu

2015-01-01

Standard trypsin digestion protocol of proteins followed by MALDI-MS analysis has been realized as an important tool for the identification and characterization of proteins. In this article, we proposed the elimination of the step of 'staining/de-staining of gel pieces' in in-gel digestion protocol in order to improve the efficiency of trypsin digestion. Coomassie dye is known to interfere with digestion of proteins by trypsin and the procedure of staining-de-staining could result in loss of photoaffinity probe, post translational modifications and catalytic activities of enzymes. Further, we studied parameters like hydrophobicity and isoelectric point, and attempted to quantitatively relate it to the efficiency of trypsin digestion. We suggest that properties of proteins should be considered and trypsin digestion protocol should be appropriately modified as per sequence and other information.

Using contaminated plants involved in phytoremediation for anaerobic digestion.

PubMed

Cao, Zewei; Wang, Shengxiao; Wang, Ting; Chang, Zhizhou; Shen, Zhenguo; Chen, Yahua

2015-01-01

This study investigated the anaerobic digestion capability of five plants and the effects of copper (Cu) and S,S'-ethylenediaminedisuccinic acid (EDDS, a chelator widely used in chelant-assisted phytoremediation) on biogas production to determine a feasible disposal method for plants used in remediation. The results showed that in addition to Phytolacca americana L., plants such as Zea mays L., Brassica napus L., Elsholtzia splendens Nakai ex F. Maekawa, and Oenothera biennis L. performed well in biogas production. Among these, O. biennis required the shortest period to finish anaerobic digestion. Compared to normal plants with low Cu content, the plants used in remediation with increased Cu levels (100 mg kg(-1)) not only promoted anaerobic digestion and required a shorter anaerobic digestion time, but also increased the methane content in biogas. When the Cu content in plants increased to 500, 1000, and 5000 mg kg(-1), the cumulative biogas production decreased by 12.3%, 14.6%, and 41.2%, respectively. Studies also found that EDDS conspicuously restrained biogas production from anaerobic digestion. The results suggest that anaerobic digestion has great potential for the disposal of contaminated plants and may provide a solution for the resource utilization of plants used in remediation.

Digestive system-related pathophysiological symptoms of Sasang typology: Systematic review.

PubMed

Lee, Mi Suk; Sohn, Kyungwoo; Kim, Yun Hee; Hwang, Min-Woo; Kwon, Young Kyu; Bae, Na Young; Chae, Han

2013-06-01

The purpose of this study was to review clinical studies on digestive system-related pathophysiological symptoms of each Sasang type to obtain the generalizable typespecific clinical features, which are important for the diagnosis of the Sasang type and subsequent disease treatment. Sasang typology and digestive system symptom-related keywords were used to search through eight domestic and foreign databases up to March 2012. The results were organized and analyzed based on four categories [digestive function, appetite, eating pattern, and body mass index (BMI)] to elucidate type-specific symptoms. Sasang type-specific digestive system-related symptoms were identified by reviewing 30 related articles that were gathered by searching through the databases. The Tae-Eum (TE) type had the highest digestive functions and the So-Eum (SE) type had the lowest. The TE type appeared to have larger volume with fast eating speed compared with the SE type and individuals in the TE category preferred fatty or salty food, which is responsible for the high occurrence rates of organic digestive diseases such as gastritis. Moreover, BMI was higher in the TE type and lower in the SE type. We systematically reviewed previously published clinical reports on digestive functions, which can be used to meet the objective of Sasang-type differentiation and pathophysiological pattern identification.

Dietary Sodium Suppresses Digestive Efficiency via the Renin-Angiotensin System.

PubMed

Weidemann, Benjamin J; Voong, Susan; Morales-Santiago, Fabiola I; Kahn, Michael Z; Ni, Jonathan; Littlejohn, Nicole K; Claflin, Kristin E; Burnett, Colin M L; Pearson, Nicole A; Lutter, Michael L; Grobe, Justin L

2015-06-11

Dietary fats and sodium are both palatable and are hypothesized to synergistically contribute to ingestive behavior and thereby obesity. Contrary to this hypothesis, C57BL/6J mice fed a 45% high fat diet exhibited weight gain that was inhibited by increased dietary sodium content. This suppressive effect of dietary sodium upon weight gain was mediated specifically through a reduction in digestive efficiency, with no effects on food intake behavior, physical activity, or resting metabolism. Replacement of circulating angiotensin II levels reversed the effects of high dietary sodium to suppress digestive efficiency. While the AT1 receptor antagonist losartan had no effect in mice fed low sodium, the AT2 receptor antagonist PD-123,319 suppressed digestive efficiency. Correspondingly, genetic deletion of the AT2 receptor in FVB/NCrl mice resulted in suppressed digestive efficiency even on a standard chow diet. Together these data underscore the importance of digestive efficiency in the pathogenesis of obesity, and implicate dietary sodium, the renin-angiotensin system, and the AT2 receptor in the control of digestive efficiency regardless of mouse strain or macronutrient composition of the diet. These findings highlight the need for greater understanding of nutrient absorption control physiology, and prompt more uniform assessment of digestive efficiency in animal studies of energy balance.

Seeking key microorganisms for enhancing methane production in anaerobic digestion of waste sewage sludge.

PubMed

Mustapha, Nurul Asyifah; Hu, Anyi; Yu, Chang-Ping; Sharuddin, Siti Suhailah; Ramli, Norhayati; Shirai, Yoshihito; Maeda, Toshinari

2018-06-01

Efficient approaches for the utilization of waste sewage sludge have been widely studied. One of them is to use it for the bioenergy production, specifically methane gas which is well-known to be driven by complex bacterial interactions during the anaerobic digestion process. Therefore, it is important to understand not only microorganisms for producing methane but also those for controlling or regulating the process. In this study, azithromycin analogs belonging to macrolide, ketolide, and lincosamide groups were applied to investigate the mechanisms and dynamics of bacterial community in waste sewage sludge for methane production. The stages of anaerobic digestion process were evaluated by measuring the production of intermediate substrates, such as protease activity, organic acids, the quantification of bacteria and archaea, and its community dynamics. All azithromycin analogs used in this study achieved a high methane production compared to the control sample without any antibiotic due to the efficient hydrolysis process and the presence of important fermentative bacteria and archaea responsible in the methanogenesis stage. The key microorganisms contributing to the methane production may be Clostridia, Cladilinea, Planctomycetes, and Alphaproteobacteria as an accelerator whereas Nitrosomonadaceae and Nitrospiraceae may be suppressors for methane production. In conclusion, the utilization of antibiotic analogs of macrolide, ketolide, and lincosamide groups has a promising ability in finding the essential microorganisms and improving the methane production using waste sewage sludge.

Enteric bacteria in aerobically digested sludge.

PubMed Central

Farrah, S R; Bitton, G

1984-01-01

Indicator bacteria, Salmonella spp., and total aerobic bacteria were determined in samples of undigested sludge and sludge that had been treated by one or two stages of aerobic digestion. Aerobic sludge digestion reduced the level of indicator bacteria by 1 to 2 log10 per g. The level of Salmonella spp. was also reduced during aerobic treatment of sludge. In general, aerobic treatment of sludge reduced, but did not eliminate, indicator bacteria and Salmonella spp. PMID:6721492

Effect of digestion temperature and pH on treatment efficiency and evolution of volatile fatty acids during thermophilic aerobic digestion of model high strength agricultural waste.

PubMed

Ugwuanyi, J Obeta; Harvey, L M; McNeil, B

2005-04-01

Thermophilic aerobic digestion (TAD) of a model agricultural waste, potato peel slurry, at soluble chemical oxygen demand (COD) load equivalent to approximately 8.0 gl(-1), was carried out under batch conditions at 0.5 vvm aeration rate. Digestions were carried out at temperatures of 45, 50, 55, 60 and 65 degrees C (or left unregulated) without pH control to study the effect of digestion temperatures on TAD. The effects of digestion pH on the process were studied at pH 6.0, 7.0, 8.0, 9.0 and 9.5 (and in unregulated control) all at 55 degrees C. Except for digestion at 65 degrees C, which was inoculated extraneously using culture of Bacillus strearothermophilus all reactions were carried out using the populations indigenous to the waste. During digestion at different temperatures, the removal of soluble COD increased with temperature to reach a peak at 60 degrees C before declining slightly, removal of soluble solid (SS) followed similar pattern and reached peak at 65 degrees C being the highest temperature studied, while the degradation of TSS and TS (TSS + TS) decreased with an increase in temperature. Digestion at pH 7.0 was more efficient than at other pH values. Acetate was the predominant volatile fatty acid (VFA) in all the reactions and accounted for up to 90% of the total. Digestion at 60 degrees C led to the greatest accumulation of acetate, and this coincided with the period of highest oxygen uptake, and rapid consumption of soluble carbohydrate. Iso-valerate was also produced at all pH values. Digestion at 55 degrees C and also at pH 7.0 led to rapid and efficient processes with least accumulation of VFA and should be of interest in full-scale processes whenever it is practicable to regulate the digestion pH and temperature. The result of digestion at unregulated pH indicates that gradual adaptation may be used to achieve efficient treatment at elevated pH values. This would be of interest in full-scale processes where it is not practicable to tightly

Plasmonic Thermal Decomposition/Digestion of Proteins: A Rapid On-Surface Protein Digestion Technique for Mass Spectrometry Imaging.

PubMed

Zhou, Rong; Basile, Franco

2017-09-05

A method based on plasmon surface resonance absorption and heating was developed to perform a rapid on-surface protein thermal decomposition and digestion suitable for imaging mass spectrometry (MS) and/or profiling. This photothermal process or plasmonic thermal decomposition/digestion (plasmonic-TDD) method incorporates a continuous wave (CW) laser excitation and gold nanoparticles (Au-NPs) to induce known thermal decomposition reactions that cleave peptides and proteins specifically at the C-terminus of aspartic acid and at the N-terminus of cysteine. These thermal decomposition reactions are induced by heating a solid protein sample to temperatures between 200 and 270 °C for a short period of time (10-50 s per 200 μm segment) and are reagentless and solventless, and thus are devoid of sample product delocalization. In the plasmonic-TDD setup the sample is coated with Au-NPs and irradiated with 532 nm laser radiation to induce thermoplasmonic heating and bring about site-specific thermal decomposition on solid peptide/protein samples. In this manner the Au-NPs act as nanoheaters that result in a highly localized thermal decomposition and digestion of the protein sample that is independent of the absorption properties of the protein, making the method universally applicable to all types of proteinaceous samples (e.g., tissues or protein arrays). Several experimental variables were optimized to maximize product yield, and they include heating time, laser intensity, size of Au-NPs, and surface coverage of Au-NPs. Using optimized parameters, proof-of-principle experiments confirmed the ability of the plasmonic-TDD method to induce both C-cleavage and D-cleavage on several peptide standards and the protein lysozyme by detecting their thermal decomposition products with matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). The high spatial specificity of the plasmonic-TDD method was demonstrated by using a mask to digest designated sections of

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; comparison of a nitric acid in-bottle digestion procedure to other whole-water digestion procedures

USGS Publications Warehouse

Garbarino, John R.; Hoffman, Gerald L.

1999-01-01

A hydrochloric acid in-bottle digestion procedure is used to partially digest wholewater samples prior to determining recoverable elements by various analytical methods. The use of hydrochloric acid is problematic for some methods of analysis because of spectral interference. The inbottle digestion procedure has been modified to eliminate such interference by using nitric acid instead of hydrochloric acid in the digestion. Implications of this modification are evaluated by comparing results for a series of synthetic whole-water samples. Results are also compared with those obtained by using U.S. Environmental Protection Agency (1994) (USEPA) Method 200.2 total-recoverable digestion procedure. Percentage yields that use the nitric acid inbottle digestion procedure are within 10 percent of the hydrochloric acid in-bottle yields for 25 of the 26 elements determined in two of the three synthetic whole-water samples tested. Differences in percentage yields for the third synthetic whole-water sample were greater than 10 percent for 16 of the 26 elements determined. The USEPA method was the most rigorous for solubilizing elements from particulate matter in all three synthetic whole-water samples. Nevertheless, the variability in the percentage yield by using the USEPA digestion procedure was generally greater than the in-bottle digestion procedure, presumably because of the difficulty in controlling the digestion conditions accurately.

Immunohistochemical localization of hepatopancreatic phospholipase A2 in Hexaplex Trunculus digestive cells

PubMed Central

2011-01-01

Background Mammalian sPLA2-IB localization cell are well characterized. In contrast, much less is known about aquatic primitive ones. The aquatic world contains a wide variety of living species and, hence represents a great potential for discovering new lipolytic enzymes and the mode of digestion of lipid food. Results The marine snail digestive phospholipase A2 (mSDPLA2) has been previously purified from snail hepatopancreas. The specific polyclonal antibodies were prepared and used for immunohistochimical and immunofluorescence analysis in order to determine the cellular location of mSDPLA2. Our results showed essentially that mSDPLA2 was detected inside in specific vesicles tentatively named (mSDPLA2+) granules of the digestive cells. No immunolabelling was observed in secretory zymogene-like cells. This immunocytolocalization indicates that lipid digestion in the snail might occur in specific granules inside the digestive cells. Conclusion The cellular location of mSDPLA2 suggests that intracellular phospholipids digestion, like other food components digestion of snail diet, occurs in these digestive cells. The hepatopancreas of H. trunculus has been pointed out as the main region for digestion, absorption and storage of lipids. PMID:21631952

Immunohistochemical localization of hepatopancreatic phospholipase A2 in Hexaplex trunculus digestive cells.

PubMed

Zarai, Zied; Boulais, Nicholas; Karray, Aida; Misery, Laurent; Bezzine, Sofiane; Rebai, Tarek; Gargouri, Youssef; Mejdoub, Hafedh

2011-06-01

Mammalian sPLA2-IB localization cell are well characterized. In contrast, much less is known about aquatic primitive ones. The aquatic world contains a wide variety of living species and, hence represents a great potential for discovering new lipolytic enzymes and the mode of digestion of lipid food. The marine snail digestive phospholipase A2 (mSDPLA2) has been previously purified from snail hepatopancreas. The specific polyclonal antibodies were prepared and used for immunohistochimical and immunofluorescence analysis in order to determine the cellular location of mSDPLA2. Our results showed essentially that mSDPLA2 was detected inside in specific vesicles tentatively named (mSDPLA2+) granules of the digestive cells. No immunolabelling was observed in secretory zymogene-like cells. This immunocytolocalization indicates that lipid digestion in the snail might occur in specific granules inside the digestive cells. The cellular location of mSDPLA2 suggests that intracellular phospholipids digestion, like other food components digestion of snail diet, occurs in these digestive cells. The hepatopancreas of H. trunculus has been pointed out as the main region for digestion, absorption and storage of lipids.

The digestive system of the stony coral Stylophora pistillata.

PubMed

Raz-Bahat, M; Douek, J; Moiseeva, E; Peters, E C; Rinkevich, B

2017-05-01

Because hermatypic species use symbiotic algal photosynthesis, most of the literature in this field focuses on this autotrophic mode and very little research has studied the morphology of the coral's digestive system or the digestion process of particulate food. Using histology and histochemestry, our research reveals that Stylophora pistillata's digestive system is concentrated at the corals' peristome, actinopharynx and mesenterial filaments (MF). We used in-situ hybridization (ISH) of the RNA transcript of the gene that codes for the S. pistillata digestive enzyme, chymotrypsinogen, to shed light on the functionality of the digestive system. Both the histochemistry and the ISH pointed to the MF being specialized digestive organs, equipped with large numbers of acidophilic and basophilic granular gland cells, as well as acidophilic non-granular gland cells, some of which produce chymotrypsinogen. We identified two types of MF: short, trilobed MF and unilobed, long and convoluted MF. Each S. pistillata polyp harbors two long convoluted MF and 10 short MF. While the short MF have neither secreting nor stinging cells, each of the convoluted MF display gradual cytological changes along their longitudinal axis, alternating between stinging and secreting cells and three distinctive types of secretory cells. These observations indicate the important digestive role of the long convoluted MF. They also indicate the existence of novel feeding compartments in the gastric cavity of the polyp, primarily in the nutritionally active peristome, in the actinopharynx and in three regions of the MF that differ from each other in their cellular components, general morphology and chymotrypsinogen excretion.

Ruminal fermentation and nutrient digestion in sheep fed hydroxyethylsoyamide.

PubMed

Jenkins, T C

1997-08-01

Hydroxyethylsoyamide (HESA) was reported previously to protect soybean oil from ruminal biohydrogenation and increase plasma unsaturated fatty acids in sheep. Two digestibility trials with sheep and a rumen in vitro trials were conducted in this study to determine the effects of HESA on ruminal VFA and nutrient digestibility. Trial 1 was a 4 x 4 Latin square with 17-d periods in which four wethers were fed either a control diet (CON) with no added fat, 2.5% soybean oil (SBO), 5% butylsoyamide (BuSA), or 5% HESA. The HESA diet was ground with a mortar and pestle before feeding to disperse fat lumps that formed during diet mixing. Compared with the CON diet, the HESA diet reduced DMI, acetate/ propionate (A/P), and total tract fiber digestibility, but these were not affected by SBO or BuSA. Trial 2 was a 24-h rumen in vitro study showing that total VFA concentration and A/P in cultures were reduced by 10% linoleic acid but not by 10% ethanolamine or 10% HESA. In Trial 3, four wethers were fed the CON and HESA diets in a replicated 2 x 2 Latin square to determine digestibility responses to HESA when grinding was avoided. Fiber digestibilities and A/P were not affected by HESA in Trial 3. The HESA in this study had variable effects on fiber digestibility that may have been related to physical attributes of the diet, including particle size. Substitution of ethanolamine for butylamine during synthesis of the amide increased fatty acid digestibility but reduced dry matter intake.

[Occupational digestive diseases in chemical industry workers of West Siberia].

PubMed

Pomytkina, T E; Pershin, A N

2010-01-01

The high incidence of chronic digestive diseases is recorded in chemical industry workers exposed to the isolated action of noxious substances. The aim of the investigation was to make a hygienic assessment of the risk for occupational digestive diseases in chemical industry workers exposed to a combination of noxious drugs. The working conditions and the prevalence of digestive diseases were studied in 4120 workers engaged in chemical and auxiliary processes. Under the isolated action of noxious substances, the workers had an average of 35% increase in the incidence of digestive diseases than unexposed ones (p < 0.05). Under the combined action of hazardous substances, the incidence of digestive diseases was 1.7-fold greater (p < 0.05) than in the unexposed subjects and 1.2-fold greater in those under isolated action. The odd ratio and relative risk for digestive diseases in the workers exposed to a combination of noxious substances were 4.0-11.1 and 3.5-10.7 times higher, respectively (p < 0.05) than in the unexposed subjects.

Frogs as integrative models for understanding digestive organ development and evolution.

PubMed

Womble, Mandy; Pickett, Melissa; Nascone-Yoder, Nanette

2016-03-01

The digestive system comprises numerous cells, tissues and organs that are essential for the proper assimilation of nutrients and energy. Many aspects of digestive organ function are highly conserved among vertebrates, yet the final anatomical configuration of the gut varies widely between species, especially those with different diets. Improved understanding of the complex molecular and cellular events that orchestrate digestive organ development is pertinent to many areas of biology and medicine, including the regeneration or replacement of diseased organs, the etiology of digestive organ birth defects, and the evolution of specialized features of digestive anatomy. In this review, we highlight specific examples of how investigations using Xenopus laevis frog embryos have revealed insight into the molecular and cellular dynamics of digestive organ patterning and morphogenesis that would have been difficult to obtain in other animal models. Additionally, we discuss recent studies of gut development in non-model frog species with unique feeding strategies, such as Lepidobatrachus laevis and Eleutherodactylous coqui, which are beginning to provide glimpses of the evolutionary mechanisms that may generate morphological variation in the digestive tract. The unparalleled experimental versatility of frog embryos make them excellent, integrative models for studying digestive organ development across multiple disciplines. Copyright © 2016 Elsevier Ltd. All rights reserved.

Frogs as integrative models for understanding digestive organ development and evolution

PubMed Central

Womble, Mandy; Pickett, Melissa; Nascone-Yoder, Nanette

2016-01-01

The digestive system comprises numerous cells, tissues and organs that are essential for the proper assimilation of nutrients and energy. Many aspects of digestive organ function are highly conserved among vertebrates, yet the final anatomical configuration of the gut varies widely between species, especially those with different diets. Improved understanding of the complex molecular and cellular events that orchestrate digestive organ development is pertinent to many areas of biology and medicine, including the regeneration or replacement of diseased organs, the etiology of digestive organ birth defects, and the evolution of specialized features of digestive anatomy. In this review, we highlight specific examples of how investigations using Xenopus laevis frog embryos have revealed insight into the molecular and cellular dynamics of digestive organ patterning and morphogenesis that would have been difficult to obtain in other animal models. Additionally, we discuss recent studies of gut development in non-model frog species with unique feeding strategies, such as Lepidobatrachus laev is and Eleutherodactylouscoqui, which are beginning to provide glimpses of the evolutionary mechanisms that may generate morphological variation in the digestive tract. The unparalleled experimental versatility of frog embryos make them excellent, integrative models for studying digestive organ development across multiple disciplines. PMID:26851628

Anaerobic co-digestion technology in solid wastes treatment for biomethane generation

NASA Astrophysics Data System (ADS)

Al Mamun, Muhammad Rashed; Torii, Shuichi

2017-05-01

Anaerobic co-digestion is considered to be an efficient way of disposing solid wastes which can not only reduce environmental burden, but also produce bioenergy. Co-digestion of solid wastes in the absence of bacteria inoculums with variable mixing ratios of three wastes has been experimentally tested for 35 days digestion time to determine the biogas potential. The temperature remained relatively constant at a mesophilic range of 29-36°C throughout the study. An average pH of 7.4 was recorded from all digesters. The average biogas yields obtained from the four digesters (D1, D2, D3 and D4) were 13.31, 15.67, 16.52 and 19.12 L/day, respectively. The cumulative result showed that from co-digestion of D4 43.67%, 22.02% and 15.71% more biogas was produced, respectively, than others. The maximum and average COD reduction was 57% and 31%, respectively, in co-digestion wastes. The biogas comprised average of 61% CH4, 33.5% CO2, 222 ppm H2S, and 4.7% H2O, respectively.

Wood digestion in Pselactus spadix Herbst--a weevil attacking marine timber structures.

PubMed

Oevering, Pascal; Pitman, Andrew J; Pandey, Krishna K

2003-04-01

Pselactus spadix tunnels timber structures in the marine environment. Recent studies reported a cosmopolitan distribution for this weevil, which is frequently found in harbour and port areas. P. spadix feeds on timber (hardwood and softwood) in immature and adult life stages, but its digestion of wood components had not been investigated. Using dry weight analyses of tunnel walls and frass produced, P. spadix adults consumed Scots pine with soft rot decay at a rate of 1.59 +/- 0.37 mg d-1 and the digestibility of this substrate was 57.96 +/- 5.89 (i.e. for 100 mg consumed SR-pine, 58 mg was digested). Using gravimetric analysis to quantify structural wood components in tunnel walls and frass, P. spadix adults were found to digest cellulose, lignin and hemicellulose with digestibility coefficients of 82.2, 41.2 and 14.5 respectively. Fourier Transform Infrared (FTIR) spectroscopy analyses of tunnel walls and frass of adults and larvae from soft rotted pine also indicated digestion of all structural components, with larvae digesting cellulose and lignin more efficiently than adults. When FTIR was employed to analyse adult tunnel walls and frass from undecayed pine, cellulose and hemicellulose were digested, but no evidence of lignin digestion was found. This study shows that adults digest lignin when soft rot is present and suggests a symbiotic function of wood degrading microorganisms.

Community Colleges: General Information and Resources. ERIC Digest.

ERIC Educational Resources Information Center

Foote, Elizabeth

This digest offers general information about American community colleges and lists a variety of sources of additional information about these institutions. The digest provides the defining characteristics of community colleges and information on their curricula; statistics on enrollments and student characteristics; information on faculty…

[Digestive disorders in rabbits and guinea pigs].

PubMed

Hollmann, P

1992-12-01

Numerous digestive tract diseases in pet rabbits and guinea pigs result from both an inherent physiological predisposition and from poor feeding and husbandry. A large proportion of digestive disturbances in rabbits and guinea pigs are secondary to changes in the oral cavity caused by inadequate teeth wear. The required regular trimming of the cheek teeth using a modified spatula and hollow pair of pincers is described and illustrated. The symptoms, diagnosis, prognosis and treatment of a selection of digestive disorders, as commonly encountered in small animal practice, are presented. The difficulties of using antibiotics in view of the gram positive intestinal flora and possible dysbacteria, dysentery and enterotoxaemia are considered. Finally, advice on feeding and on the rearing of orphan neonates is given.

First muon acceleration using a radio-frequency accelerator

NASA Astrophysics Data System (ADS)

Bae, S.; Choi, H.; Choi, S.; Fukao, Y.; Futatsukawa, K.; Hasegawa, K.; Iijima, T.; Iinuma, H.; Ishida, K.; Kawamura, N.; Kim, B.; Kitamura, R.; Ko, H. S.; Kondo, Y.; Li, S.; Mibe, T.; Miyake, Y.; Morishita, T.; Nakazawa, Y.; Otani, M.; Razuvaev, G. P.; Saito, N.; Shimomura, K.; Sue, Y.; Won, E.; Yamazaki, T.

2018-05-01

Muons have been accelerated by using a radio-frequency accelerator for the first time. Negative muonium atoms (Mu- ), which are bound states of positive muons (μ+) and two electrons, are generated from μ+'s through the electron capture process in an aluminum degrader. The generated Mu- 's are initially electrostatically accelerated and injected into a radio-frequency quadrupole linac (RFQ). In the RFQ, the Mu- 's are accelerated to 89 keV. The accelerated Mu- 's are identified by momentum measurement and time of flight. This compact muon linac opens the door to various muon accelerator applications including particle physics measurements and the construction of a transmission muon microscope.

Proteome analysis of digestive fluids in Nepenthes pitchers

PubMed Central

Rottloff, Sandy; Miguel, Sissi; Biteau, Flore; Nisse, Estelle; Hammann, Philippe; Kuhn, Lauriane; Chicher, Johana; Bazile, Vincent; Gaume, Laurence; Mignard, Benoit; Hehn, Alain; Bourgaud, Frédéric

2016-01-01

Background and Aims Carnivorous plants have developed strategies to enable growth in nutrient-poor soils. For the genus Nepenthes, this strategy represents producing pitcher-modified leaves that can trap and digest various prey. These pitchers produce a digestive fluid composed of proteins, including hydrolytic enzymes. The focus of this study was on the identification of these proteins. Methods In order to better characterize and have an overview of these proteins, digestive fluid was sampled from pitchers at different stages of maturity from five species of Nepenthes (N. mirabilis, N. alata, N. sanguinea, N. bicalcarata and N. albomarginata) that vary in their ecological niches and grew under different conditions. Three complementary approaches based on transcriptomic resources, mass spectrometry and in silico analysis were used. Key Results This study permitted the identification of 29 proteins excreted in the pitchers. Twenty of these proteins were never reported in Nepenthes previously and included serine carboxypeptidases, α- and β-galactosidases, lipid transfer proteins and esterases/lipases. These 20 proteins display sequence signals allowing their secretion into the pitcher fluid. Conclusions Nepenthes pitcher plants have evolved an arsenal of enzymes to digest prey caught in their traps. The panel of new proteins identified in this study provides new insights into the digestive process of these carnivorous plants. PMID:26912512

Sequential Anaerobic/Aerobic Digestion for Enhanced Carbon/Nitrogen Removal and Cake Odor Reduction.

PubMed

Ahmad, Muneer; Denee, Marco Abel; Jiang, Hao; Eskicioglu, Cigdem; Kadota, Paul; Gregonia, Theresa

2016-12-01

  Anaerobic digestion (AD) has been proven to be an effective process for the treatment of wastewater sludge. However, it produces high levels of ammonia in the digester effluent, which may jeopardize meeting stringent nutrient discharge limits. In this study, the effect of a sequential anaerobic/aerobic (AN/AERO) digestion and a single-stage conventional AN digestion (as control) was investigated on mixed (primary + secondary) sludge generated by the Annacis Island wastewater treatment plant (WWTP) (BC, Canada). An overall sludge retention time (SRT) of 22.5 days under three different scenarios was chosen based on the current operational SRT of the digesters at the Annacis Island WWTP. The steady state results have shown that sequential AN/AERO digestion configurations achieved up to 11% higher volatile solids (VS) removal and 72% lower ammonia generation over single-stage conventional AN digestion. Furthermore, sequential AN/AERO system also showed enhanced dewaterability, improved fecal coliform destruction and reduced digested cake odors over control digesters.

Adenylyl cyclases in the digestive system

PubMed Central

Sabbatini, Maria Eugenia; Gorelick, Fred; Glaser, Shannon

2015-01-01

Adenylyl cyclases (ACs) are a group of widely distributed enzymes whose functions are very diverse. There are nine known transmembrane AC isoforms activated by Gαs. Each has its own pattern of expression in the digestive system and differential regulation of function by Ca2+ and other intracellular signals. In addition to the transmembrane isoforms, one AC is soluble and exhibits distinct regulation. In this review, the basic structure, regulation and physiological roles of ACs in the digestive system are discussed. PMID:24521753

Anaerobic Co-digestion for Enhanced Renewable Energy and Green House Gas Emission Reduction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Navaratnam, Navaneethan; Zitomer, Daniel

2012-05-01

The need to develop renewable energy is important for replacing fossil fuel, which is limited in quantity and also tends to increase in price over time. The addition of high strength organic wastes in municipal anaerobic digesters is growing and tends to increase renewable energy production. In addition, conversion of wastes to energy significantly reduces uncontrolled greenhouse gas emissions. Co-digestion of municipal sludge with any combination of wastes can result in synergistic, antagonistic or neutral outcomes. The objectives of this study were to identify potential co-digestates, determine synergistic, antagonistic and neutral effects, determine economic benefits, quantify performance of bench scalemore » co-digesters, identify influence of co-digestion on microbial communities and implement appropriate co-digestion, if warranted, after full-scale testing. A market study was used to identify promising co-digestates. Most promising wastes were determined by biochemical methane potential (BMP) and other testing followed by a simple economic analysis. Performance was investigated using bench-scale digesters receiving synthetic primary sludge with and without co-digestates. Denaturing gradient gel electrophoresis (DGGE) and quantitative polymerase chain reaction (qPCR) analyses were performed on the gene encoding the α subunit of methyl coenzyme M reductase (mcrA) to compare methanogen communities among the digesters. One significant band contributing to the greatest difference in banding patterns was excised, cloned, amplified and sequenced. Full- scale co-digestion was conducted using the most promising co-digestate at South Shore Wastewater Reclamation Facility (Oak Creek, WI). Over 80 wastes were identified from 54 facilities within 160 km of an existing municipal digester. A simple economic comparison identified the greatest benefits for seven co-digestates. Methane production rates of two co- digester systems increased by 105% and 66% in comparison to a

PARTICLE ACCELERATOR

DOEpatents

Teng, L.C.

1960-01-19

ABS>A combination of two accelerators, a cyclotron and a ring-shaped accelerator which has a portion disposed tangentially to the cyclotron, is described. Means are provided to transfer particles from the cyclotron to the ring accelerator including a magnetic deflector within the cyclotron, a magnetic shield between the ring accelerator and the cyclotron, and a magnetic inflector within the ring accelerator.

Optimization of conditions for thermal treatment of rice bran using an accelerator including an organo-iron compound.

PubMed

Kanno, Hikari; Tachibana, Naoya; Fukushima, Masami

2011-02-01

A method for thermal conversion of raw organic waste (ROW) to a compost-like material (CLM) with higher levels of unsaturated carbohydrates, nitrogen- and oxygen-containing compounds was developed, in which rice bran and an organo-iron compound were employed as a model ROW and the accelerator, respectively. To evaluate the qualities of CLMs, organic substances of an acid insoluble fraction of alkaline extracts (AIAEs) from a CLM were structurally characterized by elemental analysis, pyrolysis-gas chromatography/mass spectrometry and FT-IR. The levels of unsaturated carbohydrates, and nitrogen- and oxygen-containing compounds in the CLM samples were increased by long-term treatment (60°C for 5 days, 170°C for 3 days). In particular, the high lipid content of the AIAEs, which was indicative of inadequate digestion of CLM components, was dramatically reduced in the presence of the accelerator. Copyright © 2010 Elsevier Ltd. All rights reserved.

Characterization of Hydrolysis Kinetics in Staged Anaerobic Digestion of Wastewater Treatment Sludge.

PubMed

Zamanzadeh, Mirzaman; Parker, Wayne J

2018-01-01

  The hydrolysis of mixed primary and secondary sludges in two-stage anaerobic digestion was evaluated and compared with conventional single-stage digestion, using various temperature-phased configurations of M1-M2, M1-T3, T1-T2, and T1-M3. A dual hydrolysis model best described the hydrolysis in all tests. This model was also able to consistently estimate the readily and slowly fractions of particulate chemical oxygen demand (COD) of raw sludge used in the tests. The hydrolysis kinetic coefficients (Khyd_s and Khyd_r) estimated for the mesophilic digesters were significantly greater in the short hydraulic retention time (HRT) M1 digester than those of the extended HRT digesters. Conversely, at thermophilic temperatures only Khyd_r was greater in short HRT T1 digester when compared to the extended HRT digesters. The increased Khyd_r and reduced Khyd_s values due to staging effect were explained with surface reaction models and endogenous decay. The temperature dependency of Khyd_s and Khyd_r was also explored in the staged digesters.

Effects of stabilization and sludge properties in a combined process of anaerobic digestion and thermophilic aerobic digestion.

PubMed

Cheng, Jiehong; Kong, Feng; Zhu, Jun; Wu, Xiao

2015-01-01

A novel process of combining mesophilic (<35°C) anaerobic digestion with the thermophilic (55°C) aerobic digestion process (AN-TAD) was designed to stabilize sludge and economize aeration energy. Effects of stabilization and sludge properties for AN-TAD process were evaluated by batch experiments during a 25 d digestion period. The sludges digested by AN-TAD process achieved the requirements for Class-A sludge standard. The sludge at total solid (TS) 5.4% had the highest value of decay coefficient K(d(55)) at 0.1851 d(-1) among the three TS contents according to the first-order kinetics equation. Oxidation reduction potential at below 0 mV remained for sludges at TSs of 6.5%, 5.4%, and 4.6% for at least 15 d because of initial hydrolytic-acidification. Concentrations of nitrogen and phosphorus in sludges at TSs of 6.5%, 5.4%, and 4.6% gradually increased up to the highest values in the supernatant during the initial 13 d, causing low utilized value in land application as a fertilizer. Prolonging the retention time for more than 15 d was considered because soluble phosphorus precipitated in the solid phase. High content of soluble organic matters of the soluble chemical oxygen demand, protein, and polysaccharide in the supernatant caused deterioration in sludge dewaterability rates.

Milk glucosidase activity enables suckled pup starch digestion

USDA-ARS?s Scientific Manuscript database

Starch requires six enzymes for digestion to free glucose: two amylases (salivary and pancreatic) and four mucosal maltase activities; sucrase-isomaltase and maltase-glucoamylase. All are deficient in suckling rodents. The objective of this study is to test (13)C-starch digestion before weaning by m...

The Media's Role in Political Campaigns. ERIC Digest.

ERIC Educational Resources Information Center

Gottlieb, Stephen S.

This digest examines the relationship between the political process and the media. The digest discusses the ramifications of advertising in politics; the role of the televised debate in elections; individual voter characteristics and the media; and media coverage and campaign awareness. Fifteen references are attached. (RS)

Digestive enzymes of human and nonhuman primates.

PubMed

Janiak, Mareike Cora

2016-09-01

All living organisms need to consume nutrients to grow, survive, and reproduce, making the successful acquisition of food resources a powerful selective pressure. However, acquiring food is only part of the challenge. While all animals spend much of their daily activity budget hunting, searching for, or otherwise procuring food, a large part of what is involved in overall nutrition occurs once the meal has been swallowed. Most nutritional components are too complex for immediate use and must be broken down into simpler compounds, which can then be absorbed by the body. This process, digestion, is catalyzed by enzymes that are either endogenous or produced by the host's microbial population. 1 Research shows that the nutritional value of food is partially constrained by the digestive abilities of the microbial community present in the host's gut and that these microbes rapidly adapt to changes in diet and other environmental pressures. 2 An accumulating body of evidence suggests that endogenously produced digestive enzymes also have been, and still are, common targets of natural selection, further cementing their crucial role in an organism's digestive system. 3-5 . © 2016 Wiley Periodicals, Inc.

The role of enzyme supplementation in digestive disorders.

PubMed

Roxas, Mario

2008-12-01

This article reviews various forms of enzyme supplementation used clinically in digestive and absorption disorders. Enzyme supplementation plays an integral role in the management of various digestive disorders, particularly with regard to exocrine pancreatic insufficiency. However, application of enzymes may also be beneficial for other conditions associated with poor digestion including lactose intolerance. Historically, porcine and bovine pancreatic enzymes have been the preferred form of supplementation for exocrine pancreatic insufficiency. Use of microbe-derived lipase has shown promise with studies indicating benefit similar to pancreatic enzymes, but at a lower dosage concentration and with a broader pH range. Safety and efficacy of enzymes derived from microbial species in the treatment of conditions such as malabsorption and lactose intolerance is promising. Plant-based enzymes, such as bromelain from pineapple, serve as effective digestive aids in the breakdown of proteins. Synergistic effects have been observed using a combination of animal-based enzymes and microbe-derived enzymes or bromelain.

Gelation of soybean protein and polysaccharides delays digestion.

PubMed

Hu, Bing; Chen, Qing; Cai, Qimeng; Fan, Yun; Wilde, Peter J; Rong, Zhen; Zeng, Xiaoxiong

2017-04-15

Xanthan gum and carrageenan, representing the medium and highly negatively charged polysaccharides, were heated respectively together with soybean protein isolate (SPI) at different biopolymer ratios. Upon mixing with simulated stomach juice (SSJ), the xanthan-SPI and carrageenan-SPI at biopolymer ratios higher than 0.01 leads to self-assembled gelation immediately. Stronger gel is formed under higher biopolymer ratios. Highly negatively charged carrageenan forms a stronger gel than that composed with xanthan gum. SDS-PAGE results show the digestibility of SPI is delayed after incorporation with the polysaccharides, which is enhanced with the increase of the biopolymer mass ratios. And the polysaccharide with higher negative charge has stronger potential in delaying the digestion of SPI. Furthermore, the microstructure of the xanthan-SPI and carrageenan-SPI gel before and after simulated stomach digestion was characterized by scanning electron microscope (SEM), which also confirms that the gel delays the digestion of soybean protein. Copyright © 2016 Elsevier Ltd. All rights reserved.

Molecular assessment of heterotrophy and prey digestion in zooxanthellate cnidarians.

PubMed

Leal, M C; Nejstgaard, J C; Calado, R; Thompson, M E; Frischer, M E

2014-08-01

Zooxanthellate cnidarians are trophically complex, relying on both autotrophy and heterotrophy. Although several aspects of heterotrophy have been studied in these organisms, information linking prey capture with digestion is still missing. We used prey-specific PCR-based tools to assess feeding and prey digestion of two zooxanthellate cnidarians - the tropical sea anemone Aiptasia sp. and the scleractinian coral Oculina arbuscula. Prey DNA disappeared rapidly for the initial 1-3 days, whereas complete digestion of prey DNA required up to 10 days in O. arbuscula and 5 or 6 days in Aiptasia sp. depending on prey species. These digestion times are considerably longer than previously reported from microscopy-based examination of zooxanthellate cnidarians and prey DNA breakdown in other marine invertebrates, but similar to prey DNA breakdown reported from terrestrial invertebrates such as heteroptera and spiders. Deprivation of external prey induced increased digestion rates during the first days after feeding in O. arbuscula, but after 6 days of digestion, there were no differences in the remaining prey levels in fed and unfed corals. This study indicates that prey digestion by symbiotic corals may be slower than previously reported and varies with the type of prey, the cnidarian species and its feeding history. These observations have important implications for bioenergetic and trophodynamic studies on zooxanthellate cnidarians. © 2013 John Wiley & Sons Ltd.

Slowly digestible starch diets alter proximal glucosidase activity and glucose absorption

USDA-ARS?s Scientific Manuscript database

Sucrase-isomaltase (Si) and maltase-glucoamylase (Mgam) are mucosal glucosidases required for digestion of starch to glucose. Ablation of maltase-Mgam reduces in vivo starch digestion. We tested whether slowly digestible starch diets induce changes in glucosidase activities. Rice starch was encaps...

Food Allergens: Is There a Correlation between Stability to Digestion and Allergenicity?

PubMed

Bøgh, Katrine Lindholm; Madsen, Charlotte Bernhard

2016-07-03

Food allergy is a major health problem in the Western countries, affecting 3-8% of the population. It has not yet been established what makes a dietary protein a food allergen. Several characteristics have been proposed to be shared by food allergens. One of these is resistance to digestion. This paper reviews data from digestibility studies on purified food allergens and evaluates the predictive value of digestibility tests on the allergenic potential. We point out that food allergens do not necessarily resist digestion. We discuss how the choice of in vitro digestibility assay condition and the method used for detection of residual intact protein as well as fragments hereof may greatly influence the outcome as well as the interpretation of results. The finding that digests from food allergens may retain allergenicity, stresses the importance of using immunological assays for evaluating the allergenic potential of food allergen digestion products. Studies assessing the allergenicity of digestion products, by either IgE-binding, elicitation or sensitizing capacity, shows that digestion may abolish, decrease, have no effect, or even increase the allergenicity of food allergens. Therefore, the predictive value of the pepsin resistance test for assessing the allergenic potential of novel proteins can be questioned.

Acceleration Modes and Transitions in Pulsed Plasma Accelerators

NASA Technical Reports Server (NTRS)

Polzin, Kurt A.; Greve, Christine M.

2018-01-01

Pulsed plasma accelerators typically operate by storing energy in a capacitor bank and then discharging this energy through a gas, ionizing and accelerating it through the Lorentz body force. Two plasma accelerator types employing this general scheme have typically been studied: the gas-fed pulsed plasma thruster and the quasi-steady magnetoplasmadynamic (MPD) accelerator. The gas-fed pulsed plasma accelerator is generally represented as a completely transient device discharging in approximately 1-10 microseconds. When the capacitor bank is discharged through the gas, a current sheet forms at the breech of the thruster and propagates forward under a j (current density) by B (magnetic field) body force, entraining propellant it encounters. This process is sometimes referred to as detonation-mode acceleration because the current sheet representation approximates that of a strong shock propagating through the gas. Acceleration of the initial current sheet ceases when either the current sheet reaches the end of the device and is ejected or when the current in the circuit reverses, striking a new current sheet at the breech and depriving the initial sheet of additional acceleration. In the quasi-steady MPD accelerator, the pulse is lengthened to approximately 1 millisecond or longer and maintained at an approximately constant level during discharge. The time over which the transient phenomena experienced during startup typically occur is short relative to the overall discharge time, which is now long enough for the plasma to assume a relatively steady-state configuration. The ionized gas flows through a stationary current channel in a manner that is sometimes referred to as the deflagration-mode of operation. The plasma experiences electromagnetic acceleration as it flows through the current channel towards the exit of the device. A device that had a short pulse length but appeared to operate in a plasma acceleration regime different from the gas-fed pulsed plasma

Correlating methane production to microbiota in anaerobic digesters fed synthetic wastewater.

PubMed

Venkiteshwaran, K; Milferstedt, K; Hamelin, J; Fujimoto, M; Johnson, M; Zitomer, D H

2017-03-01

A quantitative structure activity relationship (QSAR) between relative abundance values and digester methane production rate was developed. For this, 50 triplicate anaerobic digester sets (150 total digesters) were each seeded with different methanogenic biomass samples obtained from full-scale, engineered methanogenic systems. Although all digesters were operated identically for at least 5 solids retention times (SRTs), their quasi steady-state function varied significantly, with average daily methane production rates ranging from 0.09 ± 0.004 to 1 ± 0.05 L-CH 4 /L R -day (L R  = Liter of reactor volume) (average ± standard deviation). Digester microbial community structure was analyzed using more than 4.1 million partial 16S rRNA gene sequences of Archaea and Bacteria. At the genus level, 1300 operational taxonomic units (OTUs) were observed across all digesters, whereas each digester contained 158 ± 27 OTUs. Digester function did not correlate with typical biomass descriptors such as volatile suspended solids (VSS) concentration, microbial richness, diversity or evenness indices. However, methane production rate did correlate notably with relative abundances of one Archaeal and nine Bacterial OTUs. These relative abundances were used as descriptors to develop a multiple linear regression (MLR) QSAR equation to predict methane production rates solely based on microbial community data. The model explained over 66% of the variance in the experimental data set based on 149 anaerobic digesters with a standard error of 0.12 L-CH 4 /L R -day. This study provides a framework to relate engineered process function and microbial community composition which can be further expanded to include different feed stocks and digester operating conditions in order to develop a more robust QSAR model. Copyright © 2016 Elsevier Ltd. All rights reserved.

Implications from distinct sulfate-reducing bacteria populations between cattle manure and digestate in the elucidation of H2S production during anaerobic digestion of animal slurry.

PubMed

St-Pierre, Benoit; Wright, André-Denis G

2017-07-01

Biogas produced from the anaerobic digestion of animal slurry consists mainly of methane (CH 4 ) and carbon dioxide (CO 2 ), but also includes other minor gases, such as hydrogen sulfide (H 2 S). Since it can act as a potent corrosive agent and presents a health hazard even at low concentrations, H 2 S is considered an undesirable by-product of anaerobic digestion. Sulfate-reducing bacteria (SRBs) have been identified as the main biological source of H 2 S in a number of natural, biological, and human-made habitats, and thus represent likely candidate microorganisms responsible for the production of H 2 S in anaerobic manure digesters. Phylogenetically, SRBs form a divergent group of bacteria that share a common anaerobic respiration pathway that allows them to use sulfate as a terminal electron acceptor. While the composition and activity of SRBs have been well documented in other environments, their metabolic potential remains largely uncharacterized and their populations poorly defined in anaerobic manure digesters. In this context, a combination of in vitro culture-based studies and DNA-based approaches, respectively, were used to gain further insight. Unexpectedly, only low to nondetectable levels of H 2 S were produced by digestate collected from a manure biogas plant documented to have persistently high concentrations of H 2 S in its biogas (2000-3000 ppm). In contrast, combining digestate with untreated manure (a substrate with comparatively lower sulfate and SRB cell densities than digestate) was found to produce elevated H 2 S levels in culture. While a 16S rRNA gene-based community composition approach did not reveal likely candidate SRBs in digestate or untreated manure, the use of the dsrAB gene as a phylogenetic marker provided more insight. In digestate, the predominant SRBs were found to be uncharacterized species likely belonging to the genus Desulfosporosinus (Peptococcaceae, Clostridiales, Firmicutes), while Desulfovibrio-related SRBs

Gas in the Digestive Tract

MedlinePlus

... Process Research Training & Career Development Funded Grants & Grant History Research Resources Research at NIDDK Technology Advancement & Transfer Meetings & Workshops Health Information Diabetes Digestive ...

Smoking and Your Digestive System

MedlinePlus

... Process Research Training & Career Development Funded Grants & Grant History Research Resources Research at NIDDK Technology Advancement & Transfer Meetings & Workshops Health Information Diabetes Digestive ...

Digest of Education Statistics 2006. NCES 2007-017

ERIC Educational Resources Information Center

Snyder, Thomas D.; Dillow, Sally A.

2007-01-01

The primary purpose of the "Digest of Education Statistics" is to provide a compilation of statistical information covering the broad field of American education from prekindergarten through graduate school. The "Digest" includes a selection of data from both government and private sources, and draws especially on the results…

Digest of Education Statistics, 2007. NCES 2008-022

ERIC Educational Resources Information Center

Snyder, Thomas D.; Dillow, Sally A.; Hoffman, Charlene M.

2008-01-01

The primary purpose of the "Digest of Education Statistics" is to provide a compilation of statistical information covering the broad field of American education from prekindergarten through graduate school. The "Digest" includes a selection of data from both government and private sources, and draws especially on the results…

Digest of Education Statistics, 2008. NCES 2009-020

ERIC Educational Resources Information Center

Snyder, Thomas D.; Dillow, Sally A.; Hoffman, Charlene M.

2009-01-01

The primary purpose of the "Digest of Education Statistics" is to provide a compilation of statistical information covering the broad field of American education from prekindergarten through graduate school. The "Digest" includes a selection of data from both government and private sources, and draws especially on the results…

Anaerobic co-digestion of sewage sludge and food waste using temperature-phased anaerobic digestion process.

PubMed

Kim, H W; Han, S K; Shin, H S

2004-01-01

This study was performed to overcome the low efficiency of anaerobic digestion of sewage sludge and food waste by combining temperature-phased digestion, sequencing batch operation, and co-digestion technology. It was demonstrated that the temperature-phased anaerobic sequencing batch reactor (TPASBR) system for the co-digestion of sewage sludge and food waste resulted in enhanced volatile solids (VS) reduction and methane production rate. At the organic loading rate (OLR) of 2.7 g VS/l/d, the TPASBR system showed the higher VS reduction (61.3%), CH4 yield (0.28 l/g VS(added)) and CH4 production rate (0.41 l CH4/l/d) than those (0.29 l CH4/l/d) of the mesophilic two-stage ASBR (MTSASBR). In the specific methanogenic activity (SMA) tests on thermophilic biomass of the TPASBR system, the average SMA of acetate (93 ml CH4/gVSS/d) was much higher than those of propionate (46 ml CH4/g VSS/d) and butyrate (76 ml CH4/g VSS/d). Also, higher specific hydrolytic activity (SHA, 217 mg COD/g VSS/d) of the biomass supported fast hydrolysis under thermophilic conditions. The track study revealed that the most active period of the 24 h cycle was between 6 and 12 h. The enhanced performance of the TPASBR system could be attributed to longer solids retention time, fast hydrolysis, higher CH4 conversion rate, and balanced nutrient condition of co-substrate. It was verified that this combination could be a promising and practical alternative for the simultaneous recycling of two types of organic fraction of municipal solid waste (OFMSW) with high stability.

Thromboembolism prevention in surgery of digestive cancer.

PubMed

Malafaia, Osvaldo; Montagnini, Andre Luís; Luchese, Angélica; Accetta, Antonio Carlos; Zilberstein, Bruno; Malheiros, Carlos Alberto; Jacob, Carlos Eduardo; Quireze-Junior, Claudemiro; Bresciani, Cláudio José Caldas; Kruel, Cleber Dario Pinto; Cecconello, Ivan; Sad, Eduardo Fonseca; Ohana, Jorge Alberto Langbeck; Aguilar-Nascimento, José Eduardo de; Manso, José Eduardo Ferreira; Ribas-Filho, Jurandir Marcondes; Santo, Marco Aurélio; Andreollo, Nelson Adami; Torres, Orlando Jorge Martins; Herman, Paulo; Cuenca, Ronaldo Mafia; Sallum, Rubens Antônio Aissar; Bernardo, Wanderley Marques

2012-01-01

The venous thromboembolism is a common complication after surgical treatment in general and, in particular, on the therapeutic management on cancer. Surgery of the digestive tract has been reported to induce this complication. Patients with digestive cancer have substantial increased risk of initial or recurrent thromboembolism. To provide to surgeons working in digestive surgery and general surgery guidance on how to make safe thromboprophylaxis for patients requiring operations in the treatment of their gastrointestinal malignancies. The guideline was based on 15 relevant clinical issues and related to the risk factors, treatment and prognosis of the patient undergoing surgical treatment of cancer on digestive tract. They focused thromboembolic events associated with operations and thromboprophylaxis. The questions were structured using the PICO (Patient, Intervention or Indicator, Comparison and Outcome), allowing strategies to generate evidence on the main primary bases of scientific information (Medline / Pubmed, Embase, Lilacs / Scielo, Cochrane Library, PreMedline via OVID). Evidence manual search was also conducted (BDTD and IBICT). The evidence was recovered from the selected critical evaluation using discriminatory instruments (scores) according to the category of the question: risk, prognosis and therapy (JADAD Randomized Clinical Trials and New Castle Ottawa Scale for studies not randomized). After defining potential studies to support the recommendations, they were selected by the strength of evidence and grade of recommendation according to the classification of Oxford, including the available evidence of greater strength. A total of 53,555 papers by title and / or abstract related to issue were found. Of this total were selected (1st selection) 478 studies that were evaluated as full-text. From them to support the recommendations were included in the consensus 132 papers. The 15 questions could be answered with evidence grade of articles with 31 A

Semi-continuous anaerobic digestion of different silage crops: VFAs formation, methane yield from fiber and non-fiber components and digestate composition.

PubMed

Pokój, T; Bułkowska, K; Gusiatin, Z M; Klimiuk, E; Jankowski, K J

2015-08-01

This study presents the results of long-term semi-continuous experiments on anaerobic digestion at an HRT of 45d with ten silages: 2 annual and 4 perennial crops, and 4 mixtures of annual with perennial crops. The composition of substrates and digestates was determined with Van Soest's fractionation method. Removal of non-fiber materials ranged from 49.4% (Miscanthus sacchariflorus) to 89.3% (Zea mays alone and mixed with M. sacchariflorus), that of fiber materials like lignin ranged from 0.005% (Z. mays alone and mixed with grasses at VS ratio of 90:10%) to 46.5% (Sida hermaphrodita). The lowest stability of anaerobic digestion, as confirmed by normalized data concentrations of volatile fatty acids, was reported for both miscanthuses and sugar sorghum. The methane yield coefficients for non-fiber and fiber materials were 0.3666 and 0.2556L/g, respectively. All digestate residues had high fertilizing value, especially those from mixtures of crops. Copyright © 2015 Elsevier Ltd. All rights reserved.

Power of Your Pancreas: Keep Your Digestive Juices Flowing

MedlinePlus

... Issues Subscribe February 2017 Print this issue The Power of Your Pancreas Keep Your Digestive Juices Flowing ... your entire digestive system working properly. Related Stories Power to the Pelvis Battling a Bulging Hernia Keeping ...

Rapid establishment of thermophilic anaerobic microbial community during the one-step startup of thermophilic anaerobic digestion from a mesophilic digester.

PubMed

Tian, Zhe; Zhang, Yu; Li, Yuyou; Chi, Yongzhi; Yang, Min

2015-02-01

The purpose of this study was to explore how fast the thermophilic anaerobic microbial community could be established during the one-step startup of thermophilic anaerobic digestion from a mesophilic digester. Stable thermophilic anaerobic digestion was achieved within 20 days from a mesophilic digester treating sewage sludge by adopting the one-step startup strategy. The succession of archaeal and bacterial populations over a period of 60 days after the temperature increment was followed by using 454-pyrosequencing and quantitative PCR. After the increase of temperature, thermophilic methanogenic community was established within 11 days, which was characterized by the fast colonization of Methanosarcina thermophila and two hydrogenotrophic methanogens (Methanothermobacter spp. and Methanoculleus spp.). At the same time, the bacterial community was dominated by Fervidobacterium, whose relative abundance rapidly increased from 0 to 28.52 % in 18 days, followed by other potential thermophilic genera, such as Clostridium, Coprothermobacter, Anaerobaculum and EM3. The above result demonstrated that the one-step startup strategy could allow the rapid establishment of the thermophilic anaerobic microbial community. Copyright © 2014 Elsevier Ltd. All rights reserved.

Exposure to polystyrene nanoplastic leads to inhibition of anaerobic digestion system.

PubMed

Fu, Shan-Fei; Ding, Jian-Nan; Zhang, Yun; Li, Yi-Fei; Zhu, Rong; Yuan, Xian-Zheng; Zou, Hua

2018-06-01

In this study, impacts of nanoplastic on the pure and mixed anaerobic digestion systems were investigated. Results showed the growth and metabolism of Acetobacteroides hydrogenigenes were partly inhibited by nanoplastic existed in the pure anaerobic digestion system. The anaerobic digestion of sewage sludge was also obviously inhibited by nanoplastic existed in the mixed anaerobic digestion system. Both the methane yield and methane production rate of the mixed anaerobic digestion system showed negative correlation with the nanoplastic concentration. Compared with anaerobic digestion system without nanoplastic, methane yield and maximum daily methane yield at the nanoplastic concentration of 0.2g/L decreased for 14.4% and 40.7%, respectively. In addition, the start-up of mixed anaerobic digestion system was prolonged by addition of nanoplastic. Microbial community structure analysis indicated the microbial community structures were also affected by nanoplastic existed in the system. At the nanoplastic concentration of 0.2g/L, the relative abundances of family Cloacamonaceae, Porphyromonadaceae, Anaerolinaceae and Gracilibacteraceae decreased partly. Conversely, the relative abundances of family Anaerolinaceae, Clostridiaceae, Geobacteraceae, Dethiosulfovibrionaceae and Desulfobulbaceae improved partly. Copyright © 2017 Elsevier B.V. All rights reserved.

Inactivation of Clostridium difficile in sewage sludge by anaerobic thermophilic digestion.

PubMed

Xu, Changyun; Salsali, Hamidreza; Weese, Scott; Warriner, Keith

2016-01-01

There has been an increase in community-associated Clostridium difficile infections with biosolids derived from wastewater treatment being identified as one potential source. The current study evaluated the efficacy of thermophilic digestion in decreasing levels of C. difficile ribotype 078 associated with sewage sludge. Five isolates of C. difficile 078 were introduced (final density of 5 log CFU/g) into digested sludge and subjected to anaerobic digestion at mesophilic (36 or 42 °C) or thermophilic (55 °C) temperatures for up to 60 days. It was found that mesophilic digestion at 36 °C did not result in a significant reduction in C. difficile spore levels. In contrast, thermophilic sludge digestion reduced endospore levels at a rate of 0.19-2.68 log CFU/day, depending on the strain tested. The mechanism of lethality was indirect - by stimulating germination then inactivating the resultant vegetative cells. Acidification of sludge by adding acetic acid (6 g/L) inhibited the germination of spores regardless of the sludge digestion temperature. In conclusion, thermophilic digestion can be applied to reduce C. difficile in biosolids, thereby reducing the environmental burden of the enteric pathogen.

Cancer stem cells of the digestive system.

PubMed

Colvin, Hugh S; Nishida, Naohiro; Koseki, Jun; Konno, Masamitsu; Kawamoto, Koichi; Tsunekuni, Kenta; Doki, Yuichiro; Mori, Masaki; Ishii, Hideshi

2014-12-01

Stem cells of the digestive system are ideal in many ways for research, given they are abundant, highly proliferative and have a uniform structural arrangement. This in turn has enormously aided the research of cancer stem cells of the digestive system, which is now shaping our understanding of cancer stem cells. In this review, the recent advances in the understanding of cancer stem cells of the digestive system have been summarized, including aspects such as their identification, origin, cell-cycle dormancy, relationship with epithelial-mesenchymal transition, cellular metabolism and the underlying molecular mechanisms. Newly acquired knowledge concerning cancer stem cells have led to the development of novel cancer therapeutics with provisional yet encouraging results. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Effect of delignification upon in vitro digestion of forage cellulose.

PubMed

Darcy, B K; Belyea, R L

1980-10-01

Orchardgrass forages harvested at two maturities (early and late) were ground through two screens (1 and 8 mm) and digested in vitro as intact forage and forage delignified by permanganate oxidation. Initial and residual cell wall, initial and residual cellulose and potentially digestible cellulose were greater in late intact forage than in the early. In the delignified forage, late cut forage had less residual cellulose than did the early, but initial and potentially digestible cellulose were similar. Particle size had less consistent and smaller effects upon cell wall and cellulose than did maturity. Cellulose of intact orchardgrass was 64% digested at 72 h vs 94% for cellulose of delignified orchardgrass. Digestion rate of cellulose was .0197 and .0220 logn units/hr for early and late cut intact forage and .0554 and .0719 logn units/hr for early and late cut delignified forage. Removal of the inhibitory effects of lignin increased the amount of digestible cellulose, increased the rate at which cellulose degraded and decreased the indigestible cellulose residue. Reduction in lignin could greatly improve forage intake and utilization at moderate levels of animal production.

Thermophilic anaerobic co-digestion of poultry litter and thin stillage.

PubMed

Sharma, Deepak; Espinosa-Solares, Teodoro; Huber, David H

2013-05-01

The purpose of this study was to test whether the performance of a thermophilic CSTR digester that has been stabilized on poultry litter will be enhanced or diminished by the addition of thin stillage as co-substrate. Replicate laboratory digesters, derived from a stable pilot-scale digester, were operated with increasing ratios (w/w) of thin stillage/poultry litter feedstock. After a period of adaptation to 20% and 40% thin stillage, digester performance showed increases in biogas, percent methane and COD removal, as well as a decrease in volatile acids. Peak performance occurred with 60% thin stillage. However, 80% thin stillage caused significant reduction of performance, including declines of methanogenic activity and COD removal. In conclusion, supplementing the thermophilic digestion of poultry litter with thin stillage improved the bioenergy (methane) output, but thin stillage became inhibitory at high concentrations. Copyright © 2013 Elsevier Ltd. All rights reserved.

Go with your gut: Digestibility and digestive function of two arid-zone Australian murids, Pseudomys australis and Notomys alexis.

PubMed