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Sample records for acid hydrolysis monosaccharide

  1. Quantitative Prediction of Cell Wall Polysaccharide Composition in Grape (Vitis vinifera L.) and Apple (Malus domestica) Skins from Acid Hydrolysis Monosaccharide Profiles

    DEFF Research Database (Denmark)

    Arnous, Anis; Meyer, Anne S.

    2009-01-01

    On the basis of monosaccharide analysis after acid hydrolysis of fruit skin samples of three wine grape cultivars, Vitis vinifera L. Cabernet Sauvignon, Merlot, and Shiraz, and of two types of apple, Malus domestica Red Delicious and Golden Delicious, an iterative calculation method is reported...

  2. Influences of acidic reaction and hydrolytic conditions on monosaccharide composition analysis of acidic, neutral and basic polysaccharides.

    Science.gov (United States)

    Wang, Qing-Chi; Zhao, Xia; Pu, Jiang-Hua; Luan, Xiao-Hong

    2016-06-05

    Monosaccharide composition analysis is important for structural characterization of polysaccharides. To investigate the influences of acidic reaction and hydrolytic conditions on monosaccharide composition analysis of polysaccharides, we chose alginate, starch, chitosan and chondroitin sulfate as representative of acidic, neutral, basic and complex polysaccharides to compare the release degree of monosaccharides under different hydrolytic conditions. The hydrolysis stability of 10 monosaccharide standards was also explored. Results showed that the basic sugars were hard to release but stable, the acidic sugars (uronic acids) were easy to release but unstable, and the release and stability of neutral sugars were in between acidic and basic sugars. In addition, the hydrolysis process was applied to monosaccharide composition analysis of Hippocampus trimaculatus polysaccharide and the appropriate hydrolytic condition was accorded with that of the above four polysaccharides. Thus, different hydrolytic conditions should be used for the monosaccharide composition analysis of polysaccharides based on their structural characteristics.

  3. Kinetics of Sawdust Hydrolysis with Dilute Hydrochloric Acid and Ferrous Chloride

    Institute of Scientific and Technical Information of China (English)

    袁传敏; 颜涌捷; 任铮伟; 李庭琛; 曹建勤

    2004-01-01

    With dilute hydrochloric acid as catalyst and promoted by ferrous chloride, hydrolysis of waste sawdust to produce monosaccharides was conducted by using an one-step method in a batch-wise operation reactor. Based on the model of first order consecutive irreversible reactions, the kinetics equation incorporating the term of catalyst concentration was obtained that is suitable for describing the hydrolysis of sawdust. Activation energies were calculated for hydrolysis of sawdust and decomposition of monosaccharides.

  4. Acid hydrolysis of cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, H.

    1980-12-01

    One of the alternatives to increase world production of etha nol is by the hydrolysis of cellulose content of agricultural residues. Studies have been made on the types of hydrolysis: enzimatic and acid. Data obtained from the sulphuric acid hydrolysis of cellulose showed that this process proceed in two steps, with a yield of approximately 95% glucose. Because of increases in cost of alternatives resources, the high demand of the product and the more economic production of ethanol from cellulose materials, it is certain that this technology will be implemented in the future. At the same time further studies on the disposal and reuse of the by-products of this production must be undertaken.

  5. Fate of microbial nitrogen, carbon, hydrolysable amino acids, monosaccharides, and fatty acids in sediment

    OpenAIRE

    Veuger, Bart; van Oevelen, Dick; Middelburg, Jack J.

    2012-01-01

    The fate of microbial carbon, nitrogen, hydrolysable amino acids (HAAs), monosaccharides, and fatty acids in sediment was investigated experimentally. The microbial community of a tidal flat sediment was labeled with C-13-enriched glucose and N-15-enriched ammonium, and sediment was incubated for up to 371 days. Analysis of total concentrations and C-13- and N-15 content of bulk sediment, hydrolysable amino acids (including D-alanine), monosaccharides, total fatty acids (TFAs), and phospholip...

  6. Fate of microbial nitrogen, carbon, hydrolysable amino acids, monosaccharides, and fatty acids in sediment

    NARCIS (Netherlands)

    Veuger, B.; van Oevelen, D.; Middelburg, J.J.

    2012-01-01

    The fate of microbial carbon, nitrogen, hydrolysable amino acids (HAAs), monosaccharides, and fatty acids in sediment was investigated experimentally. The microbial community of a tidal flat sediment was labeled with C-13-enriched glucose and N-15-enriched ammonium, and sediment was incubated for up

  7. Fate of microbial nitrogen, carbon, hydrolysable amino acids, monosaccharides, and fatty acids in sediment

    NARCIS (Netherlands)

    Veuger, B.; Van Oevelen, D.; Middelburg, J.J.

    2012-01-01

    The fate of microbial carbon, nitrogen, hydrolysable amino acids (HAAs), monosaccharides, and fatty acids in sediment was investigated experimentally. The microbial community of a tidal flat sediment was labeled with 13C-enriched glucose and 15N-enriched ammonium, and sediment was incubated for up t

  8. Production of monosaccharides from napier grass by hydrothermal process with phosphoric acid.

    Science.gov (United States)

    Takata, Eri; Tsutsumi, Ken; Tsutsumi, Yuji; Tabata, Kenji

    2013-09-01

    The production of monosaccharides from napier grass was investigated in the presence of acid catalysts using the hydrothermal process. When the napier grass was treated with 3 wt.% phosphoric acid at 160°C for 15min, the xylose yield reached 10.3 wt.%, corresponding to 72.0% of the xylan in it, whereas glucose was hardly obtained. A combined process was then conducted using an 85 wt.% phosphoric acid treatment at 60 °C for 1h followed by a hydrothermal treatment with 3 wt.% phosphoric acid. In the initial treatment with concentrated phosphoric acid the most of xylan was hydrolyzed to xylose, and the crystalline cellulose was converted to its amorphous form. The hydrolysis of cellulose to glucose was significantly enhanced during the following hydrothermal process with 3 wt.% phosphoric acid at 200 °C for 8 min. Consequently, 77.2% yield of xylose and 50.0% yield of glucose were obtained from the combined process.

  9. APPLICATION OF A PSEUDO-KINETIC GENERALIZED SEVERITY MODEL TO THE CONCENTRATED SULFURIC ACID HYDROLYSIS OF PINEWOOD AND ASPENWOOD

    Directory of Open Access Journals (Sweden)

    Kando K. Janga,

    2012-05-01

    Full Text Available The yield of monosaccharides after two-stage concentrated sulfuric acid hydrolysis of softwood (Scots pine and hardwood (trembling aspen was modeled using a generalized severity parameter with a time-independent rate constant. The severity parameter, which combines the major operating variables acid concentration, temperature, and reaction time in the decrystallization stage into a single reaction ordinate, was successfully used to describe monosaccharide yields after a standardized hydrolysis stage. Conversion of cellulose to glucose demanded a higher severity to reach maximum glucose yields than the conversion of hemicelluloses to their respective monosaccharides, and the conversion of pine demanded a higher severity to obtain maximum monosaccharide yields as compared to aspen. The results indicate that the generalized severity parameter can be a useful tool for the prediction of sugar yields in a two-stage concentrated sulfuric acid hydrolysis process.

  10. Fate of microbial nitrogen, carbon, hydrolysable amino acids, monosaccharides, and fatty acids in sediment

    Science.gov (United States)

    Veuger, Bart; van Oevelen, Dick; Middelburg, Jack J.

    2012-04-01

    The fate of microbial carbon, nitrogen, hydrolysable amino acids (HAAs), monosaccharides, and fatty acids in sediment was investigated experimentally. The microbial community of a tidal flat sediment was labeled with 13C-enriched glucose and 15N-enriched ammonium, and sediment was incubated for up to 371 days. Analysis of total concentrations and 13C- and 15N content of bulk sediment, hydrolysable amino acids (including D-alanine), monosaccharides, total fatty acids (TFAs), and phospholipid-derived fatty acids (PLFAs) allowed us to trace the fate of microbial biomass and -detritus and the major biochemical groups therein (proteins, carbohydrates, and lipids) over intermediate time scales (weeks-months). Moreover, the unidentified fraction of the labeled material (i.e. not analyzed as HAA, FA, or carbohydrate) provided information on the formation and fate of molecularly uncharacterizable organic matter. Loss of 13C and 15N from the sediment was slow (half live of 433 days) which may have been due to the permanently anoxic conditions in the experiment. Loss rates for the different biochemical groups were also low with the following order of loss rate constants: PLFA > TFA > HAA > monosaccharides. The unidentified 13C-pool was rapidly formed (within days) and then decreased relatively slowly, resulting in a gradual relative accumulation of this pool over time. Degradation and microbial reworking of the labeled material resulted in subtle, yet consistent, diagenetic changes within the different biochemical groups. In the HAA pool, glycine, lysine, and proline were lost relatively slowly (i.e. best preserved) while there was no accumulation of D-alanine relative to L-alanine, indicating no relative accumulation of bacterial macromolecules rich in D-alanine. In the fatty acid pool, there was very little difference between PLFAs and TFAs, indicating a very similar lability of these pools. Differences between individual fatty acids included a relatively slow loss of i15

  11. Interaction Between Some Monosaccharides and Aspartic Acid in Dilute Aqueous Solutions

    Science.gov (United States)

    Kulikova, Galina A.

    2008-01-01

    Interaction between aspartic acid and d-glucose, d-galactose, and d-fructose has been studied by isothermal titration calorimetry, calorimetry of dissolution, and densimetry. It has been found that d-glucose and d-fructose form thermodynamically stable associates with aspartic acid, in contrast to d-galactose. The selectivity in the interaction of aspartic acid with monosaccharides is affected by their stereochemical structures. PMID:19669542

  12. Evaluation of hyper thermal acid hydrolysis of Kappaphycus alvarezii for enhanced bioethanol production.

    Science.gov (United States)

    Ra, Chae Hun; Nguyen, Trung Hau; Jeong, Gwi-Taek; Kim, Sung-Koo

    2016-06-01

    Hyper thermal (HT) acid hydrolysis of Kappaphycus alvarezii, a red seaweed, was optimized to 12% (w/v) seaweed slurry content, 180mM H2SO4 at 140°C for 5min. The maximum monosaccharide concentration of 38.3g/L and 66.7% conversion from total fermentable monosaccharides of 57.6g/L with 120gdw/L K. alvarezii slurry were obtained from HT acid hydrolysis and enzymatic saccharification. HT acid hydrolysis at a severity factor of 0.78 efficiently converted the carbohydrates of seaweed to monosaccharides and produced a low concentration of inhibitory compounds. The levels of ethanol production by separate hydrolysis and fermentation with non-adapted and adapted Kluyveromyces marxianus to high concentration of galactose were 6.1g/L with ethanol yield (YEtOH) of 0.19 at 84h and 16.0g/L with YEtOH of 0.42 at 72h, respectively. Development of the HT acid hydrolysis process and adapted yeast could enhance the overall ethanol fermentation yields of K. alvarezii seaweed.

  13. Enzymatic and acid hydrolysis of Tetraselmis suecica for polysaccharide characterization.

    Science.gov (United States)

    Kermanshahi-pour, Azadeh; Sommer, Toby J; Anastas, Paul T; Zimmerman, Julie B

    2014-12-01

    Carbohydrate composition of the marine microalgae, Tetraselmis suecica was characterized following acidic and enzymatic hydrolysis. Monitoring intracellular starch as a function of cultivation time at varying nitrate concentrations showed a maximum cellular starch content of 45% of dry biomass when grown under nitrate depleted conditions. Characterization of the cell wall methanolysates using GC/MS showed that the monosaccharide composition did not change in response to the nitrate concentration and consisted of 54% 3-deoxy-D-manno-oct-2-ulosonic acid (Kdo), 17% 3-deoxy-lyxo-2-heptulosaric acid (Dha), 21% galacturonic acid and 6% galactose. Presence of up to 5% Kdo in the dry weight of T. suecica established in this study demonstrates the potential of the cell wall of this species as a feedstock for Kdo, a sugar that is difficult to obtain by chemical synthesis and that has applications in medicinal chemistry.

  14. Fluorene-based boronic acids as fluorescent chemosensor for monosaccharides at physiological pH.

    Science.gov (United States)

    Hosseinzadeh, Rahman; Mohadjerani, Maryam; Pooryousef, Mona

    2015-08-01

    Two fluorene-based boronic acids, 9,9-dimethyl-9H-fluoren-2-yl-2-boronic acid (1) and 9,9-dimethyl-9H-fluoren-2,7-diyl-2,7-diboronic acid (2), were synthesized and their sensing abilities for detection of D-monosaccharides were investigated by fluorescence at physiological pH. It was found that both boronic acids 1 and 2 have high selectivity and sensitivity for D-fructose with stability constant of 47.2 and 412.9, respectively. The sensor 2 showed a linear response toward D-fructose in the concentration range from 5 × 10(-5) to 10(-1) mol L(-1) with the detection limit of 2 × 10(-5) mol L(-1). Copyright © 2014 John Wiley & Sons, Ltd.

  15. Separation of phenolic acids from monosaccharides by low-pressure nanofiltration integrated with laccase pre-treatments

    DEFF Research Database (Denmark)

    Luo, Jianquan; Zeuner, Birgitte; Morthensen, Sofie Thage

    2015-01-01

    monosaccharides (xylose, arabinose, glucose). Four commercial NF membranes (NF270, NP030, NTR7450 and NP010) were evaluated at different pH values and with various laccase pre-treatments (for polymerization of phenolic acids). The results showed that with increasing pH, the retentions of phenolic acids by NF...... increased, reaching 86–88% for NTR7450 and 90–94% for NF270 at pH 9.55. The retentions of monosaccharides kept almost constant (pH but significantly increased at pH 9.55 for the NF270 membrane due to enhancement of solute interactions. Phenolic acids...... could be polymerized by laccase and then completely retained by the NF membranes via size exclusion at pH 5.15. The formation of large polymeric products by laccase could alleviate the irreversible fouling in/on a NF membrane and decrease the monosaccharide retention, while the small polymeric products...

  16. Experimental study and product analysis of lignocellulosic biomass hydrolysis under extremely low acids

    Institute of Scientific and Technical Information of China (English)

    Shurong WANG; Xinshu ZHUANG; Zhongyang LUO; Kefa CEN

    2008-01-01

    Using our self-designed facility for lignocellulo-sic biomass hydrolysis under extremely low acid, and under the optimal reaction conditions of hemicellulose and cel-lulose determined by xylan and quantitative filter paper as the model, two-step dilute acid hydrolysis was carried out in detail on pine, fast-growing poplar and maize straw. The corresponding conversion ratio is 41.78%, 57.84% and 53.44% and the total reducing sugar conversion ratio is 39.28%, 42.83% and 23.82% respectively. Simultaneously, sugar component analysis of the products was performed by high performance liquid chromatography (HPLC) and monosaccharide and oligosaccharide content were com-pared. Finally, poplar hydrolysis residues were analyzed by proximate and ultimate analysis.

  17. Improved method for the analysis of the composition of polysaccharides by total acid hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Mochtar, M.; Delavier, H.J.; Oei Ban Liang

    1985-06-20

    The analysis of the composition of polysaccharides, i.e. dextran, by total acid hydrolysis, in the presence or absence of oxygen, and by different methods of neutralization of the hydrolysate, is presented. It was found that hydrolysis of polysaccharides under nitrogen atmosphere, in the absence of oxygen, diminishes the possibility of a decomposition of monosaccharides formed during hydrolysis. The neutralization of the acid hydrolysate by passing it through a column of weak-base ion exchange resin. Amberlite IRA-94, instead of neutralizing the hydrolysate by Ba(OH)/sub 2/ diminishes the possibility of epimerization of glucose to other saccharides. This improved method gives more reliable results, even in the presence of readily decomposed polysaccharides.

  18. L-lactic acid production from apple pomace by sequential hydrolysis and fermentation.

    Science.gov (United States)

    Gullón, Beatriz; Yáñez, Remedios; Alonso, José Luis; Parajó, J C

    2008-01-01

    The potential of apple pomace (a solid waste from cider and apple juice making factories) as a source of sugars and other compounds for fermentation was evaluated. The effect of the cellulase-to-solid ratio (CSR) and the liquor-to-solid ratio (LSR) on the kinetics of glucose and total monosaccharide generation was studied. Mathematical models suitable for reproducing and predicting the hydrolyzate composition were developed. When samples of apple pomace were subjected to enzymatic hydrolysis, the glucose and fructose present in the raw material as free monosaccharides were extracted at the beginning of the process. Using low cellulase and cellobiase charges (8.5 FPU/g-solid and 8.5 IU/g-solid, respectively), 79% of total glucan was saccharified after 12 h, leading to solutions containing up to 43.8 g monosaccharides/L (glucose, 22.8 g/L; fructose, 14.8 g/L; xylose+mannose+galactose, 2.5 g/L; arabinose+rhamnose, 2.8g/L). These results correspond to a monosaccharide/cellulase ratio of 0.06 g/FPU and to a volumetric productivity of 3.65 g of monosaccharides/L h. Liquors obtained under these conditions were used for fermentative lactic acid production with Lactobacillus rhamnosus CECT-288, leading to media containing up to 32.5 g/L of L-lactic acid after 6 h (volumetric productivity=5.41 g/L h, product yield=0.88 g/g).

  19. Sulfonic acid heterogeneous catalysts for dehydration of C6-monosaccharides to 5-hydroxymethylfurfural in dimethyl sulfoxide

    Institute of Scientific and Technical Information of China (English)

    Gabriel Morales; Juan A.Melero; Marta Paniagua; Jose Iglesias; Blanca Hernández; María Sanz

    2014-01-01

    Sulfonic acid-functionalized heterogeneous catalysts have been evaluated in the catalytic dehydra-tion of C6 monosaccharides into 5-hydroxymethylfurfural (HMF) using dimethyl sulfoxide (DMSO) as solvent. Sulfonic commercial resin Amberlyst-70 was the most active catalyst, which was as-cribed to its higher concentration of sulfonic acid sites as compared with the other catalysts, and it gave 93 mol%yield of HMF from fructose in 1 h. With glucose as the starting material, which is a much more difficult reaction, the reaction conditions (time, temperature, and catalyst loading) were optimized for Amberlyst-70 by a response surface methodology, which gave a maximum HMF yield of 33 mol%at 147°C with 23 wt%catalyst loading based on glucose and 24 h reaction time. DMSO promotes the dehydration of glucose into anhydroglucose, which acts as a reservoir of the substrate to facilitate the production of HMF by reducing side reactions. Catalyst reuse without a regeneration treatment showed a gradual but not very significant decay in catalytic activity.

  20. Monomeric carbohydrates production from olive tree pruning biomass: modeling of dilute acid hydrolysis.

    Science.gov (United States)

    Puentes, Juan G; Mateo, Soledad; Fonseca, Bruno G; Roberto, Inês C; Sánchez, Sebastián; Moya, Alberto J

    2013-12-01

    Statistical modeling and optimization of dilute sulfuric acid hydrolysis of olive tree pruning biomass has been performed using response surface methodology. Central composite rotatable design was applied to assess the effect of acid concentration, reaction time and temperature on efficiency and selectivity of hemicellulosic monomeric carbohydrates to d-xylose. Second-order polynomial model was fitted to experimental data to find the optimum reaction conditions by multiple regression analysis. The monomeric d-xylose recovery 85% (as predicted by the model) was achieved under optimized hydrolysis conditions (1.27% acid concentration, 96.5°C and 138 min), confirming the high validity of the developed model. The content of d-glucose (8.3%) and monosaccharide degradation products (0.1% furfural and 0.04% 5-hydroxymethylfurfural) provided a high quality subtract, ready for subsequent biochemical conversion to value-added products.

  1. Reviving the Acid Hydrolysis Process of Lignocellulosic Material in Biorefinery

    National Research Council Canada - National Science Library

    Rui Chen; Shengdong Zhu; Cunwu Chen; Bo Cheng; Jie Chen; Yuanxin Wu

    2014-01-01

    .... Use of ionic liquids and solid acids during LM hydrolysis has provided potential technical tools to overcome these problems and has given new life to the LM acid hydrolysis process in the biorefinery. This editorial will discuss the role of the LM acid hydrolysis process in the LM biorefinery, provide an analysis of the conventional LM acid hydrolysis process, and briefly discuss new developments in the LM acid process.

  2. Quantification of solubilized hemicellulose from pretreated lignocellulose by acid hydrolysis and high-performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Bjerre, A.B.; Ploeger, A.; Simonsen, T.; Woidemann, A.; Schmidt, A.S.

    1996-11-01

    An investigation of the acid hydrolysis and HPLC analysis have been carried out in order to optimise the quantification of the solubilized hemicellulose fraction from wheat straw lignocellulose after pretreatment. Different acid hydrolyses have been performed to identify which conditions (concentrations of acid and hydrolysis time) gave the maximal quantification of the solubilized hemicellulose (measured as monosaccharides). Four different sugars were identified: xylose, arabinose, glucose and galactose. Some hydrolyses were carried out on aqueous samples and some using freeze-dried samples. The best overall hydrolysis was obtained by treatment of an aqueous sample with 4 %w/v sulfuric acid for 10 minutes. These conditions were not optimal for the determination of glucose, which was estimated by using a correction factor. A purification step was needed following the acid hydrolysis, and included a sulfate precipitation by barium hydroxide and elimination of remaining ions by mixed-bed ion exchange. The level of barium hydroxide addition significantly reduced the recovery of the sugars. Thus, lower than equivalent amounts of barium hydroxide were added in the purification step. For monosaccharide analysis two different HPLC columns, i.e. Aminex HPX-87P and HPX-87H with different resin ionic forms, lead (Pb{sup 2+}) and hydrogen (H{sup +}), respectively. The lead column (HPX-87P) separated all four sugars in the acid hydrolyzates, but sample purification required the removal of all interfering impurities, which resulted in poor reproducibility and a sugar recovery below 50%. The hydrogen column (HPX-87H) separated only glucose, xylose and arabinose, whereas galactose was not separated from xylose; however, the column was less sensitive towards impurities and gave improved recovery and reproducibility. Therefore, the hydrogen column (HPX-87H) was chosen for routine quantification of the hydrolyzed hemicellulose sugars. (au) 11 tabs., 8 ills., 19 refs.

  3. A Comparative Kinetic Study of Acidic Hydrolysis of Wastes ...

    African Journals Online (AJOL)

    A Comparative Kinetic Study of Acidic Hydrolysis of Wastes Cellulose from Agricultural Derived Biomass. ... fuels and chemicals offers potential economical, environmental and strategic ... Keywords: Agricultural wastes; cellulose; acid hydrolysis; first-order rate kinetics; activation energy, Arrhenius equation ... Article Metrics.

  4. [Structural characterization of Astragalus polysaccharides using partial acid hydrolysis-hydrophilic interaction liquid chromatography-mass spectrometry].

    Science.gov (United States)

    Liang, Tu; Fu, Qing; Xin, Huaxia; Li, Fangbing; Jin, Yu; Liang, Xinmiao

    2014-12-01

    Water-soluble polysaccharides from traditional Chinese medicine (TCM) have properties of broad-spectrum treatment and low toxicity, making them as important components in natural medicines and health products. In order to solve the problem of polysaccharides characterization caused by their complex structures, a "bottom-up" approach was developed to complete the characterization of polysaccharides from Astragalus. Firstly, Astragalus pieces were extracted with hot water and then were precipitated by ethanol to obtain Astragalus polysaccharides. Secondly, a partial acid hydrolysis method was carried out and the effects of time, acid concentration and temperature on hydrolysis were investigated. The degree of hydrolysis increased along with the increase of hydrolysis time and acid concentration. The temperature played a great role in the hydrolysis process. No hydrolysis of the polysaccharides occurred at low temperature, while the polysaccharides were almost hydrolyzed to monosaccharide at high temperature. Under the optimum hydrolysis conditions (4 h, 1.5 mol/L trifluoroacetic acid, and 80 °C), Astragalus polysaccharides were hydrolyzed to characteristic oligosaccharide fragments. At last, a hydrophilic liquid chromatography-mass spectrometry method was used for the separation and structural characterization of the polysaccharide hydrolysates. The results showed that the resulting polysaccharides were mainly 1--> 4 linear glucan, and gluco-oligosaccharides with the degrees of polymerization (DP) of 4 - 11 were obtained after partial acid hydrolysis. The significance of this study is that it is the guidance for the characterization of other TCM polysaccharides.

  5. Microwave-assisted Weak Acid Hydrolysis of Proteins

    Directory of Open Access Journals (Sweden)

    Miyeong Seo

    2012-06-01

    Full Text Available Myoglobin was hydrolyzed by microwave-assisted weak acid hydrolysis with 2% formic acid at 37 oC, 50 oC, and100 oC for 1 h. The most effective hydrolysis was observed at 100 oC. Hydrolysis products were investigated using matrixassistedlaser desorption/ionization time-of-flight mass spectrometry. Most cleavages predominantly occurred at the C-termini ofaspartyl residues. For comparison, weak acid hydrolysis was also performed in boiling water for 20, 40, 60, and 120 min. A 60-min weak acid hydrolysis in boiling water yielded similar results as a 60-min microwave-assisted weak acid hydrolysis at100 oC. These results strongly suggest that microwave irradiation has no notable enhancement effect on acid hydrolysis of proteinsand that temperature is the major factor that determines the effectiveness of weak acid hydrolysis.

  6. ACID HYDROLYSIS OF HEMICELLULOSE FROM SUGARCANE BAGASSE

    Directory of Open Access Journals (Sweden)

    A. PESSOA JR.

    1997-09-01

    Full Text Available Hydrolysis of the hemicellulosic fraction of sugarcane bagasse by sulphuric acid was performed in laboratory (25 mL and semi-pilot (25 L reactors under different conditions of temperature, time and acid concentration. On the laboratory scale, the three highest recovery yields were obtained at: 140ºC for 10 min with 100 mgacid/gdm (yield=73.4%; 140ºC for 20 min with 100 mgacid/gdm (yield=73.9% and 150ºC for 20 min with 70 mgacid/gdm (yield=71.8%. These conditions were also used for hydrolysis in a semi-pilot reactor, and the highest xylose recovery yield (83.3% was obtained at 140ºC for 20 min with 100 mgacid/gdm

  7. Acid-functionalized nanoparticles for biomass hydrolysis

    Science.gov (United States)

    Pena Duque, Leidy Eugenia

    Cellulosic ethanol is a renewable source of energy. Lignocellulosic biomass is a complex material composed mainly of cellulose, hemicellulose, and lignin. Biomass pretreatment is a required step to make sugar polymers liable to hydrolysis. Mineral acids are commonly used for biomass pretreatment. Using acid catalysts that can be recovered and reused could make the process economically more attractive. The overall goal of this dissertation is the development of a recyclable nanocatalyst for the hydrolysis of biomass sugars. Cobalt iron oxide nanoparticles (CoFe2O4) were synthesized to provide a magnetic core that could be separated from reaction using a magnetic field and modified to carry acid functional groups. X-ray diffraction (XRD) confirmed the crystal structure was that of cobalt spinel ferrite. CoFe2O4 were covered with silica which served as linker for the acid functions. Silica-coated nanoparticles were functionalized with three different acid functions: perfluoropropyl-sulfonic acid, carboxylic acid, and propyl-sulfonic acid. Transmission electron microscope (TEM) images were analyzed to obtain particle size distributions of the nanoparticles. Total carbon, nitrogen, and sulfur were quantified using an elemental analyzer. Fourier transform infra-red spectra confirmed the presence of sulfonic and carboxylic acid functions and ion-exchange titrations accounted for the total amount of catalytic acid sites per nanoparticle mass. These nanoparticles were evaluated for their performance to hydrolyze the beta-1,4 glycosidic bond of the cellobiose molecule. Propyl-sulfonic (PS) and perfluoropropyl-sulfonic (PFS) acid functionalized nanoparticles catalyzed the hydrolysis of cellobiose significantly better than the control. PS and PFS were also evaluated for their capacity to solubilize wheat straw hemicelluloses and performed better than the control. Although PFS nanoparticles were stronger acid catalysts, the acid functions leached out of the nanoparticle during

  8. The nutritional role of free sialic acid, a human milk monosaccharide, and its application as a functional food ingredient.

    Science.gov (United States)

    Röhrig, Christoph H; Choi, Sharon S H; Baldwin, Nigel

    2017-03-24

    N-Acetyl-d-neuraminic acid (NANA), more commonly known by its trivial name sialic acid, is an endogenous human and ubiquitous nutritional monosaccharide. As a bound sugar at the terminal positions of glycans NANA is known to play important roles in many biological events. The data that exist on the occurrence of the free monosaccharide in breast milk and nutrition, however, are less commonly discussed. In most foods of animal origin, sialic acid occurs as a mixture of NANA and N-glycolyl-d-neuraminic acid (NGNA), a hydroxylated derivative of NANA that is not found in humans. The dietary intake of NGNA has been identified as a risk factor for long-term adverse health effects. Therefore, we present summaries on the biochemistry, metabolism, bioavailability, and the data on NANA and NGNA levels that occur in diverse foods. Finally, we discuss the emerging data demonstrating that free NANA is linked to positive nutritional effects including pronounced antioxidative properties. These data and the extremely high safety profile of NANA justify dietary enrichment at levels that correspond to the dietary intake of NANA in infants through breast milk.

  9. Comparison of microwave oven and convection oven for acid hydrolysis of dietary fiber polysaccharides.

    Science.gov (United States)

    Li, B W

    1998-01-01

    Hydrolysis of dietary fiber polysaccharides (DFP) is an integral part of any enzymatic-chemical method for dietary fiber analysis. Residues obtained after enzyme treatments of fiber-containing foods are usually suspended in 12 M sulfuric acid and kept at or slightly above ambient temperature for at least 1 h, and then the mixtures are diluted with deionized water to a final concentration of 1 M or 2 M acid, followed by heating at 100 degrees C in a water bath or convection oven for 1 or 2 h. Under these hydrolytic conditions, some degradation of the released monosaccharides generally takes place over the duration of hydrolysis. We investigated the feasibility of using microwave energy as a heat source to reduce time and minimize degradation. Preliminary tests were done on the well-characterized soy polysaccharide Fibrim. With a microwave digestion system equipped with temperature and pressure monitors and control lines, optimum settings of power (5%, 75%), time (up to 3 min and 30 s), temperature (35 degrees-55 degrees C), and pressure (45-65 psi) were determined for different foods depending on the residue weight and volume of acid. Results were comparable for microwave oven and convection oven hydrolysis of DFP from 5 foods with good correlations for neutral sugar values; r2 = 0.997 for arabinose, 0.925 for galactose, 0.981 for glucose, 0.969 for mannose, and 0.990 for xylose.

  10. Hyper-thermal acid hydrolysis and adsorption treatment of red seaweed, Gelidium amansii for butyric acid production with pH control.

    Science.gov (United States)

    Ra, Chae Hun; Jeong, Gwi-Taek; Kim, Sung-Koo

    2017-03-01

    Optimal hyper-thermal (HT) acid hydrolysis conditions for Gelidium amansii were determined to be 12% (w/v) seaweed slurry content and 144 mM H2SO4 at 150 °C for 10 min. HT acid hydrolysis-treated G. amansii hydrolysates produced low concentrations of inhibitory compounds and adsorption treatment using 3% activated carbon. An adsorption time of 5 min was subsequently used to remove the inhibitory 5-hydroxymethylfurfural from the medium. A final maximum monosaccharide concentration of 44.6 g/L and 79.1% conversion from 56.4 g/L total fermentable monosaccharides with 120 g dw/L G. amansii slurry was obtained from HT acid hydrolysis, enzymatic saccharification, and adsorption treatment. This study demonstrates the potential for butyric acid production from G. amansii hydrolysates under non-pH-controlled as well as pH-controlled fermentation using Clostridium acetobutylicum KCTC 1790. The activated carbon treatment and pH-controlled fermentation showed synergistic effects and produced butyric acid at a concentration of 11.2 g/L after 9 days of fermentation.

  11. Enhanced functional properties of tannic acid after thermal hydrolysis

    Science.gov (United States)

    Thermal hydrolysis processing of fresh tannic acid was carried out in a closed reactor at four different temperatures (65, 100, 150 and 200°C). Pressures reached in the system were 1.3 and 4.8 MPa at 150 and 200°C, respectively. Hydrolysis products (gallic acid and pyrogallol) were separated and qua...

  12. Simultaneous separation and quantitative determination of monosaccharides, uronic acids, and aldonic acids by high performance anion-exchange chromatography coupled with pulsed amperometric detection in corn stover prehydrolysates

    Directory of Open Access Journals (Sweden)

    Xing Wang

    2012-11-01

    Full Text Available A method for simultaneous separation and quantitative determination of arabinose, galactose, glucose, xylose, xylonic acid, gluconic acid, galacturonic acid, and glucuronic acid was developed by using high performance anion-exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD. The separation was performed on a CarboPacTM PA-10 column (250 mm × 2 mm with a various gradient elution of NaOH-NaOAc solution as the mobile phase. The calibration curves showed good linearity (R2 ≥ 0.9993 for the monosaccharides, uronic acids, and aldonic acids in the range of 0.1 to 12.5 mg/L. The detection limits (LODs and the quantification limits (LOQs were 4.91 to 18.75 μg/L and 16.36 to 62.50 μg/L, respectively. Relative standard deviations (RSDs of the retention times and peak areas for the seven consecutive determinations of an unknown amount of mixture were 0.15% to 0.44% and 0.22% to 2.31%, respectively. The established method was used to separate and determine four monosaccharides, two uronic acids, and two aldonic acids in the prehydrolysate from dilute acid steam-exploded corn stover within 21 min. The spiked recoveries of monosaccharides, uronic acids, and aldonic acids ranged from 91.25% to 108.81%, with RSDs (n=3 of 0.04% ~ 6.07%. This method was applied to evaluate the quantitative variation of sugar and sugar acid content in biomass prehydrolysates.

  13. Characterization of Soil Humin by Acid Hydrolysis

    Institute of Scientific and Technical Information of China (English)

    李云峰; 徐建民; 等

    1999-01-01

    Studies were conducted to characterize soil humin by acid hydrolysis.Two humin samples collected from two different types of soil,namely chernozem and laterite,which are widespread over a vast area from the north to south of China,were hyrolyzed under reflux with 0.5M H2SO4or 3M H2SO4for 4h.The results showed that 25%-29% of organic carbon and 46%-54%of organic nitrogen could be hydrolyzed by 0.5M H2SO4;36%-40%of organic carbon and 93%-97% of organic nitrogen hydrolyzed by 3M H2SO4.The C/N ration in hydrolyzed organic matter is lower than that in soil humin and that in organic matter hydrolyzed by 3M H2SO4 is lower than that in organic matter hydrolyzed by 0.5M H2SO4.The proportion of nitrogen hydrolyzed from humin is markedly larger than that from the original soil and also markedly larger than that from humic acid fraction.Only 3%-7% of nitrogen in humin exists in a relatively stable from,which is not easy to hydrolyze.There in little nitrogen that occurs in the form of heterocyclic rings in humin.Incubation experiments showed that the newly formed organic matter can be hydrolyzed more easily.

  14. Analysis of monosaccharides, fatty constituents and rare O-acetylated sialic acids from gonads of the starfish Asterias rubens.

    Science.gov (United States)

    Zanetta, Jean-Pierre; Srinivasan, Vinayaga; Schauer, Roland

    2006-02-01

    A previous study (Bergwerff et al., Biochimie 74 (1992) 25-37) reported that sialic acids present in Asterias rubens gonads were essentially composed of 8-methyl-N-glycolylneuraminic acid (Neu5Gc8Me), a large part of it being acetylated in position 9. Using GC/MS of heptafluorobutyrate derivatives (Zanetta et al., Glycobiology 11 (2001) 663-676) on the chloroform/methanol soluble and insoluble fractions, we showed that most sialic acids were found in the latter and demonstrated that all sialic acids were derived from N-glycolylneuraminic acid, most of them being 8-methylated, but that the majority were also acetylated in position 4 or 7 (or both positions). GC/MS analyses of the constituents liberated using acid-catalysed methanolysis verified that major glycoprotein-bound glycans were N-linked and of the gluco-oligomannosidic type. Major fatty acids were poly-unsaturated (especially C20:4) and long-chain bases were C22:1 phytosphingosine and C22:2 6-hydroxysphingenine. Major monosaccharides found in the chloroform/methanol extract (quinovose and fucose) were derived from steroidal saponins.

  15. A simple chip free-flow electrophoresis for monosaccharide sensing via supermolecule interaction of boronic acid functionalized quencher and fluorescent dye.

    Science.gov (United States)

    Yin, Xiao-Yang; Dong, Jing-Yu; Wang, Hou-Yu; Li, Si; Fan, Liu-Yin; Cao, Cheng-Xi

    2013-08-01

    Here, a simple micro free-flow electrophoresis (μFFE) was developed for fluorescence sensing of monosaccharide via supermolecule interaction of synthesized boronic acid functionalized benzyl viologen (ο-BBV) and fluorescent dye. The μFFE contained two open electrode cavities and an ion-exchange membrane was sandwiched between two polymethylmethacrylate plates. The experiments demonstrated the following merits of developed μFFE: (i) up to 90.5% of voltage efficiency due to high conductivity of ion-exchange membrane; (ii) a strong ability against influence of bubble produced in two electrodes due to open design of electrode cavities; and (iii) reusable and washable separation chamber (45 mm × 17 mm × 100 μm, 77 μL) avoiding the discard of μFFE due to blockage of solute precipitation in chamber. Remarkably, the μFFE was first designed for the sensing of monosaccharide via the supermolecule interaction of synthesized ο-BBV, fluorescent dye, and monosaccharide. Under the optimized conditions, the minimum concentration of monosaccharide that could be detected was 1 × 10(-11) M. Finally, the developed device was used for the detection of 0.3 mM glucose spiked in human urine. All of the results demonstrated the feasibility of monosaccharide detection via the μFFE.

  16. Furfural production from fruit shells by acid-catalyzed hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Demirbas, A. [Selcuk Univ., Konya (Turkey). Dept. of Chemical Engineering

    2006-01-21

    Pentosans are hydrolyzed to pentoses by dilute mineral acid hydrolysis. The main source of pentosans is hemicelluloses. Furfural can be produced by the acid hydrolysis of pentosan from fruit shells such as hazelnut, sunflower, walnut, and almond of agricultural wastes. Further dehydration reactions of the pentoses yield furfural. The hydrolysis of each shell sample was carried out in dilute sulfuric acid (0.05 to 0.200 mol/l), at high temperature (450-525 K), and short reaction times (from 30 to 600 s). (author)

  17. A Comparative Study of Ferulic Acid on Different Monosaccharide-Mediated Protein Glycation and Oxidative Damage in Bovine Serum Albumin

    Directory of Open Access Journals (Sweden)

    Sirichai Adisakwattana

    2013-11-01

    Full Text Available Three dietary monosaccharides, (glucose, fructose, and ribose, have different rates of protein glycation that accelerates the production of advanced glycation end-products (AGEs. The present work was conducted to investigate the effect of ferulic acid (FA on the three monosaccharide-mediated protein glycations and oxidation of BSA. Comparing the percentage reduction, FA (1–5 mM reduced the level of fluorescence AGEs (F-AGEs and Nε-(carboxymethyl lysine (Nε-CML in glucose-glycated BSA (F-AGEs = 12.61%–36.49%; Nε-CML = 33.61%–66.51%, fructose-glycated BSA (F-AGEs = 25.28%–56.42%; Nε-CML = 40.21%–62.91%, and ribose-glycated BSA (F-AGEs = 25.63%–51.18%; Nε-CML = 26.64%–64.08%. In addition, the percentages of FA reduction of fructosamine (Frc and amyloid cross β-structure (Amy were Frc = 20.45%–43.81%; Amy = 17.84%–34.54% in glucose-glycated BSA, Frc = 25.17%–36.92%; Amy = 27.25%–39.51% in fructose-glycated BSA, and Frc = 17.34%–29.71%; Amy = 8.26%–59.92% in ribose-glycated BSA. FA also induced a reduction in protein carbonyl content (PC and loss of protein thiol groups (TO in glucose-glycated BSA (PC = 37.78%–56.03%; TO = 6.75%–13.41%, fructose-glycated BSA (PC = 36.72%–52.74%; TO = 6.18%–20.08%, and ribose-glycated BSA (PC = 25.58%–33.46%; TO = 20.50%–39.07%. Interestingly, the decrease in fluorescence AGEs by FA correlated with the level of Nε-CML, fructosamine, amyloid cross β-structure, and protein carbonyl content. Therefore, FA could potentially be used to inhibit protein glycation and oxidative damage caused by monosaccharides, suggesting that it might prevent AGEs-mediated pathologies during diabetic complications.

  18. INFLUENCE OF ACID CONCENTRATION, TEMPERATURE, AND TIME ON THE CONCENTRATED SULFURIC ACID HYDROLYSIS OF PINEWOOD AND ASPENWOOD: A STATISTICAL APPROACH

    Directory of Open Access Journals (Sweden)

    Kando K. Janga

    2011-11-01

    Full Text Available The effects on sugar yields of acid concentration, temperature, and time in the first (decrystallization stage of a two-stage concentrated sulfuric acid hydrolysis of softwood (Scots pine and hardwood (aspen were investigated. The study focused on the multi-variable effects of the decrystallization stage and applied a statistical modeling with Central Composite Face (CCF design of experiment to systematically study and simulate the effect of decrystallization reaction conditions on hydrolysis products and degradation products. The models were statistically significant and showed that for both aspen and pine, the reaction temperature and acid concentration were the most influential variables on monosaccharides and total sugar yields compared to the reaction time. The interaction between temperature and acid concentration was the most important for both species. The sugar degradation products were much influenced by the decrystallization temperature on both aspen and pine. The models were validated by a test-set and showed a good agreement between the experimental and predicted values. The optimum predicted total sugar yields were 56 g / 100 g d.w for aspen (74% theoretical and 64 g / 100 g d.w for pine (91% theoretical.

  19. Hydrolysis of isocyanic acid on SCR catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Elsener, M.; Kleemann, M.; Koebel, M. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1999-08-01

    Standard SCR catalysts possess high activity for the hydrolysis of HNCO and thus explain the suitability of urea as a selective reducing agent for NO{sub x}. At high space velocities HNCO-slip can get perceptible over the entire temperature range. This can be attributed to the fact that the temperature dependence is strong for the SCR reaction, but weak for the hydrolysis reaction. (author) 3 figs., 5 refs.

  20. Degradation of Opioids and Opiates During Acid Hydrolysis Leads to Reduced Recovery Compared to Enzymatic Hydrolysis.

    Science.gov (United States)

    Sitasuwan, Pongkwan; Melendez, Cathleen; Marinova, Margarita; Mastrianni, Kaylee R; Darragh, Alicia; Ryan, Emily; Lee, L Andrew

    2016-10-01

    Drug monitoring laboratories utilize a hydrolysis process to liberate the opiates from their glucuronide conjugates to facilitate their detection by tandem mass spectrometry (MS). Both acid and enzyme hydrolysis have been reported as viable methods, with the former as a more effective process for recovering codeine-6-glucuronide and morphine-6-glucuronide. Here, we report concerns with acid-catalyzed hydrolysis of opioids, including a significant loss of analytes and conversions of oxycodone to oxymorphone, hydrocodone to hydromorphone and codeine to morphine. The acid-catalyzed reaction was monitored in neat water and patient urine samples by liquid chromatography-time-of-flight and tandem MS. These side reactions with acid hydrolysis may limit accurate quantitation due to loss of analytes, possibly lead to false positives, and poorly correlate with pharmacogenetic profiles, as cytochrome P450 enzyme (CYP2D6) is often involved with oxycodone to oxymorphone, hydrocodone to hydromorphone and codeine to morphine conversions. Enzymatic hydrolysis process using the purified, genetically engineered β-glucuronidase (IMCSzyme(®)) addresses many of these concerns and demonstrates accurate quantitation and high recoveries for oxycodone, hydrocodone, oxymorphone and hydromorphone.

  1. Degradation of hyaluronic acid, poly- and monosaccharides, and model compounds by hypochlorite

    DEFF Research Database (Denmark)

    Hawkins, C L; Davies, Michael Jonathan

    1998-01-01

    Degradation of hyaluronic acid by oxidants such as HO. and HOCl/CIO- is believed to be important in the progression of rheumatoid arthritis. While reaction of hyaluronic acid with HO. has been investigated extensively, reaction with HOCl/ClO- is less well defined. Thus, little is known about the ...

  2. Citrate-Linked Keto- and Aldo-Hexose Monosaccharide Cellulose Conjugates Demonstrate Selective Human Neutrophil Elastase-Lowering Activity in Cotton Dressings

    Directory of Open Access Journals (Sweden)

    Sonya Caston-Pierre

    2013-05-01

    Full Text Available Sequestration of harmful proteases as human neutrophil elastase (HNE from the chronic wound environment is an important goal of wound dressing design and function. Monosaccharides attached to cellulose conjugates as ester-appended aldohexoses and ketohexoses were prepared on cotton gauze as monosccharide-citrate-cellulose-esters for HNE sequestration. The monosaccharide-cellulose analogs demonstrated selective binding when the derivatized cotton dressings were measured for sequestration of HNE. Each monosaccharide-cellulose conjugate was prepared as a cellulose citrate-linked monosaccharide ester on the cotton wound dressing, and assayed under wound exudate-mimicked conditions for elastase sequestration activity. A series of three aldohexose and four ketohexose ester cellulose conjugates were prepared on cotton gauze through citric acid-cellulose cross linking esterification. The monosaccharide portion of the conjugate was characterized by hydrolysis of the citrate-monosaccharide ester bond, and subsequent analysis of the free monosaccharide with high performance anion exchange chromatography. The ketohexose and aldohexose conjugate levels on cotton were quantified on cotton using chromatography and found to be present in milligram/gram amounts. The citrate-cellulose ester bonds were characterized with FTIR. Ketohexose-citrate-cellulose conjugates sequestered more elastase activity than aldohexose-citrate-cellulose conjugates. The monosaccharide cellulose conjugate families each gave distinctive profiles in elastase-lowering effects. Possible mechanisms of elastase binding to the monosaccharide-cellulose conjugates are discussed.

  3. In vitro enzymic hydrolysis of chlorogenic acids in coffee.

    Science.gov (United States)

    da Encarnação, Joana Amarante; Farrell, Tracy L; Ryder, Alexandra; Kraut, Nicolai U; Williamson, Gary

    2015-02-01

    Coffee is rich in quinic acid esters of phenolic acids (chlorogenic acids) but also contains some free phenolic acids. A proportion of phenolic acids appear in the blood rapidly after coffee consumption due to absorption in the small intestine. We investigated in vitro whether this appearance could potentially be derived from free phenolic acids in instant coffee or from hydrolysis of chlorogenic acids by pancreatic or brush border enzymes. We quantified six free phenolic acids in instant coffees using HPLC-DAD-mass spectrometry. The highest was caffeic acid, but all were present at low levels compared to the chlorogenic acids. Roasting and decaffeination significantly reduced free phenolic acid content. We estimated, using pharmacokinetic modelling with previously published data, that the contribution of these compounds to small intestinal absorption is minimal. Hydrolysis of certain chlorogenic acids was observed with human-differentiated Caco-2 cell monolayers and with porcine pancreatin, which showed maximal rates on 3- and 5-O-caffeoylquinic acids, respectively. The amounts of certain free phenolic acids in coffee could only minimally account for small intestinal absorption based on modelling. The hydrolysis of caffeoylquinic, but not feruloylquinic acids, by enterocyte and pancreatic esterases is potentially a contributing mechanism to small intestinal absorption. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. ESTIMATION OF PHOSPHATE ESTER HYDROLYSIS RATE CONSTANTS. II. ACID AND GENERAL BASE CATALYZED HYDROLYSIS

    Science.gov (United States)

    SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to calculate acid and neutral hydrolysis rate constants of phosphate esters in water. The rate is calculated from the energy difference between the initial and transition states of a ...

  5. Kinetic study on the acid-catalyzed hydrolysis of cellulose to levulinic acid

    NARCIS (Netherlands)

    Girisuta, B.; Janssen, L. P. B. M.; Heeres, H. J.

    2007-01-01

    A variety of interesting bulk chemicals is accessible by the acid-catalyzed hydrolysis of cellulose. An interesting example is levulinic acid, a versatile precursor for fuel additives, polymers, and resins. A detailed kinetic study on the acid-catalyzed hydrolysis of cellulose to levulinic acid is

  6. A new boronic acid fluorescent sensor based on fluorene for monosaccharides at physiological pH

    Science.gov (United States)

    Hosseinzadeh, Rahman; Mohadjerani, Maryam; Pooryousef, Mona; Eslami, Abbas; Emami, Saeed

    2015-06-01

    Fluorescent boronic acids are very useful fluorescent sensor for detection of biologically important saccharides. Herein we synthesized a new fluorene-based fluorescent boronic acid that shows significant fluorescence changes upon addition of saccharides at physiological pH. Upon addition of fructose, sorbitol, glucose, galactose, ribose, and maltose at different concentration to the solution of 7-(dimethylamino)-9,9-dimethyl-9H-fluoren-2-yl-2-boronic acid (7-DMAFBA, 1), significant decreases in fluorescent intensity were observed. It was found that this boronic acid has high affinity (Ka = 3582.88 M-1) and selectivity for fructose over glucose at pH = 7.4. The sensor 1 showed a linear response toward D-fructose in the concentrations ranging from 2.5 × 10-5 to 4 × 10-4 mol L-1 with the detection limit of 1.3 × 10-5 mol L-1.

  7. Validation of lignocellulosic biomass carbohydrates determination via acid hydrolysis.

    Science.gov (United States)

    Zhou, Shengfei; Runge, Troy M

    2014-11-04

    This work studied the two-step acid hydrolysis for determining carbohydrates in lignocellulosic biomass. Estimation of sugar loss based on acid hydrolyzed sugar standards or analysis of sugar derivatives was investigated. Four model substrates (starch, holocellulose, filter paper and cotton) and three levels of acid/material ratios (7.8, 10.3 and 15.4, v/w) were studied to demonstrate the range of test artifacts. The method for carbohydrates estimation based on acid hydrolyzed sugar standards having the most satisfactory carbohydrate recovery and relative standard deviation. Raw material and the acid/material ratio both had significant effect on carbohydrate hydrolysis, suggesting the acid to have impacts beyond a catalyst in the hydrolysis. Following optimal procedures, we were able to reach a carbohydrate recovery of 96% with a relative standard deviation less than 3%. The carbohydrates recovery lower than 100% was likely due to the incomplete hydrolysis of substrates, which was supported by scanning electron microscope (SEM) images.

  8. Simultaneous hydrolysis-esterification of wet microalgal lipid using acid.

    Science.gov (United States)

    Takisawa, Kenji; Kanemoto, Kazuyo; Kartikawati, Muliasari; Kitamura, Yutaka

    2013-12-01

    This research demonstrated hydrolysis of wet microalgal lipid and esterification of free fatty acid (FFA) using acid in one-step process. The investigation of simultaneous hydrolysis-esterification (SHE) of wet microalgal lipid was conducted by using L27 orthogonal design and the effects of water content, volume of sulphuric acid, volume of methanol, temperature and time on SHE were examined. As a result, water content was found to be the most effective factor. The effects of various parameters on fatty acid methyl ester (FAME) content and equilibrium relation between FAME and FFA were also examined under water content 80%. Equimolar amounts of sulphuric acid and hydrochloric acid showed similar results. This method has great potential in terms of biodiesel production from microalgae since no organic solvents are used.

  9. Study of Enzymatic Hydrolysis of Dilute Acid Pretreated Coconut Husk

    Directory of Open Access Journals (Sweden)

    Rudy Agustriyanto

    2012-12-01

    Full Text Available Coconut husk is classified as complex lignocellulosic material that contains cellulose, hemicellulose, lignin, and some other extractive compounds. Cellulose from coconut husk can be used as fermentation substrate after enzymatic hydrolysis. In contrary, lignin content from the coconut husk will act as an inhibitor in this hydrolysis process. Therefore, a pretreatment process is needed to enhance the hydrolysis of cellulose. The objective of this research is to investigate the production of the glucose through dilute acid pretreatment and to obtain its optimum operating conditions. In this study, the pretreatment was done using dilute sulfuric acid in an autoclave reactor. The pretreatment condition were varied at 80°C, 100°C, 120°C and 0.9%, 1.2%, 1.5% for temperature and acid concentration respectively. The acid pretreated coconut husk was then hydrolyzed using commercial cellulase (celluclast and β-glucosidase (Novozyme 188. The hydrolysis time was 72 hours and the operating conditions were varied at several temperature and pH. From the experimental results it can be concluded that the delignification temperature variation has greater influence than the acid concentration. The optimum operating condition was obtained at pH 4 and 50°C which was pretreated at 100°C using 1.5% acid concentration. Copyright © 2012 by BCREC UNDIP. All rights reserved. (Selected Paper from International Conference on Chemical and Material Engineering (ICCME 2012Received: 28th September 2012, Revised: 2nd October 2012, Accepted: 4th October 2012[How to Cite: R. Agustriyanto, A. Fatmawati, Y. Liasari. (2012. Study of Enzymatic Hydrolysis of Dilute Acid Pretreated Coconut Husk. Bulletin of Chemical Reaction Engineering & Catalysis, 7(2: 137-141. doi:10.9767/bcrec.7.2.4046.137-141] [How to Link / DOI: http://dx.doi.org/10.9767/bcrec.7.2.4046.137-141 ] | View in 

  10. Role of bifidobacteria in the hydrolysis of chlorogenic acid.

    Science.gov (United States)

    Raimondi, Stefano; Anighoro, Andrew; Quartieri, Andrea; Amaretti, Alberto; Tomás-Barberán, Francisco A; Rastelli, Giulio; Rossi, Maddalena

    2015-02-01

    This study aimed to explore the capability of potentially probiotic bifidobacteria to hydrolyze chlorogenic acid into caffeic acid (CA), and to recognize the enzymes involved in this reaction. Bifidobacterium strains belonging to eight species occurring in the human gut were screened. The hydrolysis seemed peculiar of Bifidobacterium animalis, whereas the other species failed to release CA. Intracellular feruloyl esterase activity capable of hydrolyzing chlorogenic acid was detected only in B. animalis. In silico research among bifidobacteria esterases identified Balat_0669 as the cytosolic enzyme likely responsible of CA release in B. animalis. Comparative modeling of Balat_0669 and molecular docking studies support its role in chlorogenic acid hydrolysis. Expression, purification, and functional characterization of Balat_0669 in Escherichia coli were obtained as further validation. A possible role of B. animalis in the activation of hydroxycinnamic acids was demonstrated and new perspectives were opened in the development of new probiotics, specifically selected for the enhanced bioconversion of phytochemicals into bioactive compounds.

  11. Intramolecular Amide Hydrolysis in N-Methylmaleamic Acid Revisited

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The intramolecular amide hydrolysis of N-methylmaleamic acid have been revisited by use of density functional theory and inclusion of solvent effects. The results indicate that concerted reaction mechanism is favored over stepwise reaction mechanism. This is in agreement with the previous theoretical study. Sovlent effects have significant influence on the reaction barrier.

  12. Carbon-based strong solid acid for cornstarch hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Nata, Iryanti Fatyasari, E-mail: yanti_tkunlam@yahoo.com [Chemical Engineering Study Program, Faculty of Engineering, Lambung Mangkurat University, Jl. A. Yani Km. 36 Banjarbaru, South Kalimantan 70714 (Indonesia); Irawan, Chairul; Mardina, Primata [Chemical Engineering Study Program, Faculty of Engineering, Lambung Mangkurat University, Jl. A. Yani Km. 36 Banjarbaru, South Kalimantan 70714 (Indonesia); Lee, Cheng-Kang, E-mail: cklee@mail.ntust.edu.tw [Department of Chemical Engineering, National Taiwan University of Science and Technology, 43 Keelung Rd. Sec.4, Taipei 106, Taiwan (China)

    2015-10-15

    Highly sulfonated carbonaceous spheres with diameter of 100–500 nm can be generated by hydrothermal carbonization of glucose in the presence of hydroxyethylsulfonic acid and acrylic acid at 180 °C for 4 h. The acidity of the prepared carbonaceous sphere C4-SO{sub 3}H can reach 2.10 mmol/g. It was used as a solid acid catalyst for the hydrolysis of cornstarch. Total reducing sugar (TRS) concentration of 19.91 mg/mL could be obtained by hydrolyzing 20 mg/mL cornstarch at 150 °C for 6 h using C4-SO{sub 3}H as solid acid catalyst. The solid acid catalyst demonstrated good stability that only 9% decrease in TRS concentration was observed after five repeat uses. The as-prepared carbon-based solid acid catalyst can be an environmentally benign replacement for homogeneous catalyst. - Highlights: • Carbon solid acid was successfully prepared by one-step hydrothermal carbonization. • The acrylic acid as monomer was effectively reduce the diameter size of particle. • The solid acid catalyst show good catalytic performance of starch hydrolysis. • The solid acid catalyst is not significantly deteriorated after repeated use.

  13. Carbon-based strong solid acid for cornstarch hydrolysis

    Science.gov (United States)

    Nata, Iryanti Fatyasari; Irawan, Chairul; Mardina, Primata; Lee, Cheng-Kang

    2015-10-01

    Highly sulfonated carbonaceous spheres with diameter of 100-500 nm can be generated by hydrothermal carbonization of glucose in the presence of hydroxyethylsulfonic acid and acrylic acid at 180 °C for 4 h. The acidity of the prepared carbonaceous sphere C4-SO3H can reach 2.10 mmol/g. It was used as a solid acid catalyst for the hydrolysis of cornstarch. Total reducing sugar (TRS) concentration of 19.91 mg/mL could be obtained by hydrolyzing 20 mg/mL cornstarch at 150 °C for 6 h using C4-SO3H as solid acid catalyst. The solid acid catalyst demonstrated good stability that only 9% decrease in TRS concentration was observed after five repeat uses. The as-prepared carbon-based solid acid catalyst can be an environmentally benign replacement for homogeneous catalyst.

  14. Dilute Acid Hydrolysis of Cowpea Hulls: A Kinetic Study

    Directory of Open Access Journals (Sweden)

    Chioma M. Onyelucheya

    2016-08-01

    Full Text Available In this study, dilute acid hydrolysis of cowpea hulls was carried out in two stages under the following conditions: pre-hydrolysis (4%v/v H2SO4, 121˚C, 30 minutes and hydrolysis ( at 10% and 15% v/v H2SO4,varied at different temperatures 150 oC, 160 oC, 170 oC and 180 oC for 2.5 hrs.. The substrate was characterized using both Fourier transform infrared spectroscopy and proximate analysis. The percentage lignocellulosic composition of the substrate was obtained for cellulose, hemicellulose and lignin as 34%, 14% and 4.7% respectively. Maximum glucose concentration of 8.09g was obtained using 10%v/v acid concentration at 170˚C after a reaction time of 90min. Saeman’s model gave a good fit for the experimental data. Activation energy for glucose formation using 10%v/v and 15%v/v H2SO4 was obtained as 38.28KJ and 82.204KJ respectively. From the results obtained it can be concluded that cowpea hulls can be converted to a useful product.

  15. Hydrolysis of bamboo fiber cellulose in formic acid

    Institute of Scientific and Technical Information of China (English)

    Yong SUN; Lu LIN; Haibo DENG; Hong PENG; Jiazhe LI; Runchang SUN; Shijie LIU

    2008-01-01

    Bamboo fiber dissolution and hydrolysis in formic acid were studied. After hydrolysis, formic acid can be recovered in a clean state and reused. Solid water-soluble sugars were obtained. After being dipped into the formic acid solution for 30 min, the bamboo fibers started to swell. After one hour, the bamboo fibers gradually started to dissolve in the formic acid solution. The color of the liquor/solution turned green and dark. In the end, the bamboo fibers became thoroughly dissolved in the liquor after four hours. There was a clear hierarch-ical tissue structure on the fiber surface, as observed by AFM before treatment. The differential structure disap-peared after 30 min of treatment. The fiber surface became plump and glossy. After six hours reaction at 60℃, the solid sugar mixture recovered contained glu-cose, cellobiose, cellotriose, cellotetrose, cellopentose and cellohexaose. A significant fraction of the sugar pro-ducts consisted of monomeric glucose. More than 54.5% of the bamboo fiber mass had been transformed into monomeric glucose.

  16. Absolute quantitation of proteins by Acid hydrolysis combined with amino Acid detection by mass spectrometry

    DEFF Research Database (Denmark)

    Mirgorodskaya, Olga A; Körner, Roman; Kozmin, Yuri P;

    2012-01-01

    Amino acid analysis is among the most accurate methods for absolute quantification of proteins and peptides. Here, we combine acid hydrolysis with the addition of isotopically labeled standard amino acids and analysis by mass spectrometry for accurate and sensitive protein quantitation...

  17. The Crystalline Changes of Starch from Rhizoma Dioscorea by Acid Hydrolysis

    Institute of Scientific and Technical Information of China (English)

    Shu Jun WANG; Wen Yuan GAO; Jing Lin YU; Pei Gen XIAO

    2006-01-01

    The changes in crystalline properties of starch from Rhizoma Dioscorea by acid hydrolysis was characterized by X-Ray diffractometry (XRD). The results revealed that the crystalline type of Rhizoma Dioscorea starch changed from C-type to A-type after 16 days of the acid hydrolysis. This phenomenon was different from that of other starches subjected to the acid hydrolysis. The results revealed that the B-polymorphs of C-type starch constituted the amorphous regions while the crystalline areas were mainly composed of A-polymorphs. The degree of crystallinity of the acid-thinned starch increased gradually with the time of acid hydrolysis.

  18. EFFECTS OF DILUTE ACID HYDROLYSIS ON COMPOSITION AND STRUCTURE OF CELLULOSE IN EULALIOPSIS BINATA

    OpenAIRE

    Jiebin Tang; Kefu Chen; Jun Xu; Jun Li; Chuanshan Zhao

    2011-01-01

    Dilute sulfuric acid hydrolysis was performed before the isolation of cellulose from Eulaliopsis binata. And then, the effects of dilute acid hydrolysis on composition and structure of the cellulose was studied in detail. The results indicated that hemicellulose was dissolved mostly and that the lignin-hemicellulose-cellulose interactions were also partially disrupted during the dilute acid hydrolysis. Cellulose in Eulaliopsis binata was identified as the cellulose I allomorph with low crysta...

  19. A Long-Wavelength Fluorescent Squarylium Cyanine Dye Possessing Boronic Acid for Sensing Monosaccharides and Glycoproteins with High Enhancement in Aqueous Solution

    Directory of Open Access Journals (Sweden)

    Hiroyuki Nakazumi

    2012-04-01

    Full Text Available Fluorescence sensing of saccharides and glycoproteins using a boronic acid functionalized squarylium cyanine dye (“SQ-BA” is characterized in terms of synthetic, fluorometric, thermodynamic and kinetic parameters. In our previous work, this newly synthesized dye was successfully applied to the separation and quantification of Gram-positive bacteria by capillary electrophoresis with laser-induced fluorescence detection (CE-LIF; however, the fundamental properties of the dye and its saccharide complexes still required elucidation, as presented in this paper. The dye itself forms nonemissive, soluble aggregates in aqueous solution. With the addition of a monosaccharide, the dye aggregate dissociates to form an emissive monomer accompanied by the formation of a cyclic cis-diol ester with long-wavelength emission (lex = 630 nm, lem = 660 nm. A very large fluorescence enhancement factor of 18× was observed for the sensing dye as a fructose complex at pH 10, yielding a limit of detection of 10 mM fructose. The relative order of fluorescence enhancement of SQ-BA with other monosaccharides was found to be: fructose > ribose > arabinose ≈ galactose > xylose > mannose > rhamnose > fucose ≈ glucose; and apparent affinity constants of 102.80, 102.08 and 100.86 M−1 were determined for fructose, ribose and glucose, respectively. Formation of the emissive complexes occurred within minutes, proving the kinetics of the sugar-dye interactions to be suitable for on-column labeling methods in CE-LIF. Furthermore, the sensing dye was successfully applied to glycoproteins, mucin type I–S and type III, which were detected with high sensitivity in batch aqueous solution as a result of the sugar-selective boronic acid-diol esterification as well as hydrophobic interactions.

  20. Simulation of acid hydrolysis of lignocellulosic residues to fermentable sugars for bioethanol production

    Science.gov (United States)

    Sidiras, Dimitris

    2012-12-01

    The dilute acid hydrolysis of fir sawdust with sulfuric acid was undertaken in a batch reactor system (autoclave). The experimental data and reaction kinetic analysis indicate that this is a potential process for cellulose and hemicelluloses hydrolysis, due to a rapid hydrolysis reaction for acid concentration 0.045 N at 160-180°C. It was found that significant sugar degradation occurred at these conditions. The optimum conditions gave a yield of 38% total fermentable sugars. The kinetics of dilute acid hydrolysis of cellulose and hemicelluloses (polysaccharides) were simulated using four pseudo-kinetic models. The reaction rate constants were calculated in each case.

  1. Hydrolysis of dilute acid-pretreated cellulose under mild hydrothermal conditions.

    Science.gov (United States)

    Chimentão, R J; Lorente, E; Gispert-Guirado, F; Medina, F; López, F

    2014-10-13

    The hydrolysis of dilute acid-pretreated cellulose was investigated in a conventional oven and under microwave heating. Two acids--sulfuric and oxalic--were studied. For both hydrothermal conditions (oven and microwave) the resultant total organic carbon (TOC) values obtained by the hydrolysis of the cellulose pretreated with sulfuric acid were higher than those obtained by the hydrolysis of the cellulose pretreated with oxalic acid. However, the dicarboxylic acid exhibited higher hydrolytic efficiency towards glucose. The hydrolysis of cellulose was greatly promoted by microwave heating. The Rietveld method was applied to fit the X-ray patterns of the resultant cellulose after hydrolysis. Oxalic acid preferentially removed the amorphous region of the cellulose and left the crystalline region untouched. On the other hand, sulfuric acid treatment decreased the ordering of the cellulose by partially disrupting its crystalline structure. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Effect of acid hydrolysis on starch structure and functionality: a review.

    Science.gov (United States)

    Wang, Shujun; Copeland, Les

    2015-01-01

    Acid hydrolysis is an important chemical modification that can significantly change the structural and functional properties of starch without disrupting its granular morphology. A deep understanding of the effect of acid hydrolysis on starch structure and functionality is of great importance for starch scientific research and its industrial applications. During acid hydrolysis, amorphous regions are hydrolyzed preferentially, which enhances the crystallinity and double helical content of acid hydrolyzed starch. This review discusses current understanding of the effect of acid hydrolysis on starch structure and functionality. The effects of acid hydrolysis on amylose content, chain length distribution of amylopectin molecules, molecular and crystalline organization (including lamellar structure) and granular morphology are considered. Functional properties discussed include swelling power, gelatinization, retrogradation, pasting, gel texture, and in vitro enzyme digestibility. The paper also highlights some promising applications of acid hydrolyzed starch (starch nanocrystals) in the preparation of biodegradable nanocomposites, bio-hydrogen, and slowly digestible starch-based healthy foods.

  3. Oscillations Produced From Acidity Hydrolysis of Triglyceride inEmulsion

    Institute of Scientific and Technical Information of China (English)

    HE, Zhan-Bo; QI, Gang

    2001-01-01

    A new type of oscillating reaction was found from the systematic cesign of the chemical oscillator in water in oil (W/O)emulsions. It is an acidity hydrolysis reaction of long chaintriglyceride in W/O emulsion at 25.0 ± 0. I°C in a bath stirring reactor. During the proeess of reaction, there were periodic and semi-periodic changes lasting more than 10 hoursboth in electrolytic conductivity and electric potential. Microscope also revealed that the emulsion structure changed regularly and puikly. Became of the large differnce in the solubility of the hydrolyzed products, it could be thought, that thediffernt redistribution in the two phases of water and oil induces the regular changes. Marangoni effect of interfacemembrane made oscillation to form. TITne oscillating reactioncan be used to explain the periodic change in the living systemprodrced from coupling between reaction and diffusion.

  4. Difference analysis of the enzymatic hydrolysis performance of acid-catalyzed steam-exploded corn stover before and after washing with water.

    Science.gov (United States)

    Zhu, Junjun; Shi, Linli; Zhang, Lingling; Xu, Yong; Yong, Qiang; Ouyang, Jia; Yu, Shiyuan

    2016-10-01

    The difference in the enzymatic hydrolysis yield of acid-catalyzed steam-exploded corn stover (ASC) before and after washing with water reached approximately 15 % under the same conditions. The reasons for the difference in the yield between ASC and washed ASC (wASC) were determined through the analysis of the composition of ASC prehydrolyzate and sugar concentration of enzymatic hydrolyzate. Salts produced by neutralization (CaSO4, Na2SO4, K2SO4, and (NH4)2SO4), sugars (polysaccharides, oligosaccharides, and monosaccharides), sugar-degradation products (weak acids and furans), and lignin-degradation products (ethyl acetate extracts and nine main lignin-degradation products) were back-added to wASC. Results showed that these products, except furans, exerted negative effect on enzymatic hydrolysis. According to the characteristics of acid-catalyzed steam explosion pretreatment, the five sugar-degradation products' mixture and salts [Na2SO4, (NH4)2SO4] showed minimal negative inhibition effect on enzymatic hydrolysis. By contrast, furans demonstrated a promotion effect. Moreover, soluble sugars, such as 13 g/L xylose (decreased by 6.38 %), 5 g/L cellobiose (5.36 %), 10 g/L glucose (3.67 %), as well as lignin-degradation products, and ethyl acetate extracts (4.87 %), exhibited evident inhibition effect on enzymatic hydrolysis. Therefore, removal of soluble sugars and lignin-degradation products could effectively promote the enzymatic hydrolysis performance.

  5. Kinetics of Strong Acid Hydrolysis of a Bleached Kraft Pulp for Producing Cellulose Nanocrystals (CNCs)

    Science.gov (United States)

    Qianqian Wang; Xuebing Zhao; J.Y. Zhu

    2014-01-01

    Cellulose nanocrytals (CNCs) are predominantly produced using the traditional strong acid hydrolysis process. In most reported studies, the typical CNC yield is low (approximately 30%) despite process optimization. This study investigated the hydrolysis of a bleached kraft eucalyptus pulp using sulfuric acid between 50 and 64 wt % at temperatures of 35−80 °C...

  6. Vitamin B2 content determination in liver paste by using acid and acid-enzyme hydrolysis

    Directory of Open Access Journals (Sweden)

    Basić Zorica

    2007-01-01

    Full Text Available Background/Aim. Vitamin B2 is available in foodstuff in the form of coenzyme and in free form. For its content determination a few procedures should be performed (deliberation from a complex, extraction of free and deliberated form and detection, identification and quantification. There is a particular problem in determination of vitamin B2 in the meat products. For a determination of total vitamin B2 content in liver paste two preparation procedures are compared: acid and acid-enzymatic hydrolysis. The aim of this study thus, was to compare the effectiveness of these two different procedures for vitamin B2 content determination in liver paste. Methods. High pressure liquid chromatography (HPLC method with fluorescence detector, as specific and adequately sensitive for the foodstuff of a complex composition with a natural vitamin content, was used for determination of vitamin B2 in liver paste. Acid hydrolysis was performed with the application 0.1 M hydrochloric acid in a pressure cooker, and enzymatic hydrolysis was performed with the 10% takadiastase on 45 ºC within four hours. Ten samples of liver paste from the supply of the Serbian Army were examined. Separation was performed on the analytical column Nucleosil 50−5 C18 with mobile phase 450 ml CH3OH + 20 ml 5 mM CH3COONH4, and detection on the fluorescent detector with the variable wave length. Both methods were validated: examining a detection limit, quantification limit, specificity (because of a possible B2 vitamin interference with reagents, linearity of a peak area and standard concentration of B2 vitamin ratio in the range from 0.05 μg/ml to 2 μg/ml, precision for the 0.05 μg/ml concentration and recovery. Results. All the previously examined parameters validated both methods as specific, precise and reproductive, with a high recovery (98.5% for acid and 98.2% for acid - enzymatic hydrolysis, as well as linearity in a range that significantly superseded the expected content in

  7. Study on the Hydrolysis Kinetics of Xylan on Different Acid Catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Na, Byeong-Il; Lee, Jae-Won [Chonnam National University, Gwangju (Korea, Republic of)

    2014-04-15

    In this study, we investigated kinetic model for the acid-catalyzed xylan hydrolysis at temperature 120-150 .deg. C. Also, we analyzed the kinetic parameters for xylose production and furfural decomposition. The hydrolysis of xylan and the degradation of xylose were promoted by high reaction temperature and acid concentration. The optimal hydrolysis condition for the highest reaction rate constants (k{sub 1}) was different depending on the acid catalysts. Among sulfuric, oxalic and maleic acid, the xylan reaction rate constants (k{sub 1}) to xylose had the highest value of 0.0241 min{sup -1} when 100 mM sulfuric acid was used at 120 .deg. C. However, sulfuric acid induced more xylose degradation compared to oxalic and maleic acid hydrolysis. The activation energy for xylan degradation was the highest when sulfuric acid was used.

  8. Comparison of Enzymatic Hydrolysis and Acid Hydrolysis of Sterol Glycosides from Foods Rich in Δ(7)-Sterols.

    Science.gov (United States)

    Münger, Linda H; Jutzi, Sabrina; Lampi, Anna-Maija; Nyström, Laura

    2015-08-01

    In this study, we present the difference in sterol composition of extracted steryl glycosides (SG) hydrolyzed by either enzymatic or acid hydrolysis. SG were analyzed from foods belonging to the plant families Cucurbitaceae (melon and pumpkin seeds) and Amaranthaceae (amaranth and beetroot), both of which are dominated by Δ(7)-sterols. Released sterols were quantified by gas chromatography with a flame ionization detector (GC-FID) and identified using gas chromatography/mass spectrometry (GC-MS). All Δ(7)-sterols identified (Δ(7)-stigmastenyl, spinasteryl, Δ(7)-campesteryl, Δ(7)-avenasteryl, poriferasta-7,25-dienyl and poriferasta-7,22,25-trienyl glucoside) underwent isomerization under acidic conditions and high temperature. Sterols with an ethylidene or methylidene side chain were found to form multiple artifacts. The artifact sterols coeluted with residues of incompletely isomerized Δ(7)-sterols, or Δ(5)-sterols if present, and could be identified as Δ(8(14))-sterols on the basis of relative retention time, and their MS spectra as trimethylsilyl (TMS) and acetate derivatives. For instance, SG from melon were composed of 66% Δ(7)-stigmastenol when enzymatic hydrolysis was performed, whereas with acid hydrolysis only 8% of Δ(7)-stigmastenol was determined. The artifact of Δ(7)-stigmastenol coeluted with residual non-isomerized spinasterol, demonstrating the high risk of misinterpretation of compositional data obtained after acid hydrolysis. Therefore, the accurate composition of SG from foods containing sterols with a double bond at C-7 can only be obtained by enzymatic hydrolysis or by direct analysis of the intact SG.

  9. Starch conversion of ganyong (Canna edulis Ker.) to bioethanol using acid hydrolysis and fermentation

    OpenAIRE

    LILY SURAYYA EKA PUTRI; DEDE SUKANDAR

    2008-01-01

    Starch of ganyong is one of the sources of ethanol which is able to be produced by acid hydrolysis and fermentation process. It had high concentration of carbohydrate that is 80%, so it could produce glucose highly within acid hydrolysis process. The result showed that the optimal amount of reducing sugar had been produced by nitrate acid 7% (dextrose equivalent, DE = 28.4). Nevertheless, type and concentration of acid had no significantly correlation to reducing sugar yielded. The total ...

  10. Enhanced enzymatic hydrolysis and acetone-butanol-ethanol fermentation of sugarcane bagasse by combined diluted acid with oxidate ammonolysis pretreatment.

    Science.gov (United States)

    Li, Hailong; Xiong, Lian; Chen, Xuefang; Wang, Can; Qi, Gaoxiang; Huang, Chao; Luo, Mutan; Chen, Xinde

    2017-03-01

    This study aims to propose a biorefinery pretreatment technology for the bioconversion of sugarcane bagasse (SB) into biofuels and N-fertilizers. Performance of diluted acid (DA), aqueous ammonia (AA), oxidate ammonolysis (OA) and the combined DA with AA or OA were compared in SB pretreatment by enzymatic hydrolysis, structural characterization and acetone-butanol-ethanol (ABE) fermentation. Results indicated that DA-OA pretreatment improves the digestibility of SB by sufficiently hydrolyzing hemicellulose into fermentable monosaccharides and oxidating lignin into soluble N-fertilizer with high nitrogen content (11.25%) and low C/N ratio (3.39). The enzymatic hydrolysates from DA-OA pretreated SB mainly composed of glucose was more suitable for the production of ABE solvents than the enzymatic hydrolysates from OA pretreated SB containing high ratio of xylose. The fermentation of enzymatic hydrolysates from DA-OA pretreated SB produced 12.12g/L ABE in 120h. These results suggested that SB could be utilized efficient, economic, and environmental by DA-OA pretreatment. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Effect of pectins on the mass transfer kinetics of monosaccharides, amino acids, and a corn oil-in-water emulsion in a Franz diffusion cell.

    Science.gov (United States)

    Espinal-Ruiz, Mauricio; Restrepo-Sánchez, Luz-Patricia; Narváez-Cuenca, Carlos-Eduardo

    2016-10-15

    The effect of high (HMP) and low (LMP) methoxylated pectins (2%w/w) on the rate and extent of the mass transfer of monosaccharides, amino acids, and a corn oil-in-water emulsion across a cellulose membrane was evaluated. A sigmoidal response kinetic analysis was used to calculate both the diffusion coefficients (rate) and the amount of nutrients transferred through the membrane (extent). In all cases, except for lysine, HMP was more effective than LMP in inhibiting both the rate and extent of the mass transfer of nutrients through the membrane. LMP and HMP, e.g., reduced 1.3 and 3.0times, respectively, the mass transfer rate of glucose, as compared to control (containing no pectin), and 1.3 and 1.5times, respectively, the amount of glucose transferred through the membrane. Viscosity, molecular interactions, and flocculation were the most important parameters controlling the mass transfer of electrically neutral nutrients, electrically charged nutrients, and emulsified lipids, respectively.

  12. Two-stage, dilute sulfuric acid hydrolysis of wood : an investigation of fundamentals

    Science.gov (United States)

    John F. Harris; Andrew J. Baker; Anthony H. Conner; Thomas W. Jeffries; James L. Minor; Roger C. Pettersen; Ralph W. Scott; Edward L Springer; Theodore H. Wegner; John I. Zerbe

    1985-01-01

    This paper presents a fundamental analysis of the processing steps in the production of methanol from southern red oak (Quercus falcata Michx.) by two-stage dilute sulfuric acid hydrolysis. Data for hemicellulose and cellulose hydrolysis are correlated using models. This information is used to develop and evaluate a process design.

  13. Investigating Mass Transport Limitations on Xylan Hydrolysis During Dilute Acid Pretreatment of Poplar

    Energy Technology Data Exchange (ETDEWEB)

    Mittal, Ashutosh; Pilath, Heid M.; Parent, Yves; Chatterjee, Siddharth G.; Donohoe, Bryon S.; Yarbrough, John M.; Himmel, Michael E.; Nimlos, Mark R.; Johnson, David K.

    2014-04-28

    Mass transport limitations could be an impediment to achieving high sugar yields during biomass pretreatment and thus be a critical factor in the economics of biofuels production. The objective of this work was to study the mass transfer restrictions imposed by the structure of biomass on the hydrolysis of xylan during dilute acid pretreatment of biomass. Mass transfer effects were studied by pretreating poplar wood at particle sizes ranging from 10 micrometers to 10 mm. This work showed a significant reduction in the rate of xylan hydrolysis in poplar when compared to the intrinsic rate of hydrolysis for isolated xylan that is possible in the absence of mass transfer. In poplar samples we observed no significant difference in the rates of xylan hydrolysis over more than two orders of magnitude in particle size. It appears that no additional mass transport restrictions are introduced by increasing particle size from 10 micrometers to 10 mm. This work suggests that the rates of xylan hydrolysis in biomass particles are limited primarily by the diffusion of hydrolysis products out of plant cell walls. A mathematical description is presented to describe the kinetics of xylan hydrolysis that includes transport of the hydrolysis products through biomass into the bulk solution. The modeling results show that the effective diffusion coefficient of the hydrolysis products in the cell wall is several orders of magnitude smaller than typical values in other applications signifying the role of plant cell walls in offering resistance to diffusion of the hydrolysis products.

  14. Impact of α-amylase combined with hydrochloric acid hydrolysis on structure and digestion of waxy rice starch.

    Science.gov (United States)

    Li, Hongyan; Zhu, Yanqiao; Jiao, Aiquan; Zhao, Jianwei; Chen, Xiaoming; Wei, Benxi; Hu, Xiuting; Wu, Chunsen; Jin, Zhengyu; Tian, Yaoqi

    2013-04-01

    The structure and in vitro digestibility of native waxy rice starch by the combined hydrolysis of α-amylase and hydrochloric acid were investigated in this study. The combined hydrolysis technique generated higher hydrolysis rate and extent than the enzymatic hydrolysis. The granular appearance and chromatograph profile demonstrated that α-amylase and hydrochloric acid exhibited different patterns of hydrolysis. The rise in the ratio of absorbance 1047/1022cm(-1), the melting temperature range (Tc-To), and the melting enthalpy (ΔH) were observed during the combined hydrolysis. These results suggest that α-amylase simultaneously cleaves the amorphous and crystalline regions, whereas the amorphous regions of starch granules are preferentially hydrolyzed during the acid hydrolysis. Furthermore, the combined hydrolysis increased rapidly digestible starch (RDS) while decreased slowly digestible starch (SDS) and resistant starch (RS), indicating that the hydrolysis mode affected the digestion property of native waxy rice starch.

  15. Comparison of dilute mineral and organic acid pretreatment for enzymatic hydrolysis of wheat straw

    NARCIS (Netherlands)

    Kootstra, A.M.J.; Beeftink, H.H.; Scott, E.L.; Sanders, J.P.M.

    2009-01-01

    The efficiencies of fumaric, maleic, and sulfuric acid in wheat straw pretreatment were compared. As a measure for pretreatment efficiency, enzymatic digestibility of the lignocellulose was determined. Monomeric glucose and xylose concentrations were measured after subsequent enzymatic hydrolysis, a

  16. Hydrolysis of tRNA(sup Phe) on Suspensions of Amino Acids

    Science.gov (United States)

    Gao, Kui; Orgel, Leslie E.

    2001-01-01

    RNA is adsorbed strongly on suspensions of many moderately soluble organic solids. In some cases, the hydrolysis of tRNA(sup Phe) is greatly accelerated by adsorption, and the major sites of hydrolysis are changed from those that are important in homogeneous solution. Here we show that the hydrolysis is greatly accelerated by suspensions of aspartic acid and beta-glutamic acid but not by suspensions of alpha-glutamic acid, asparagine, or glutamine. The non-enzymatic hydrolysis of RNA has been studied extensively, especially because of its relevance to the mechanisms of action of ribozymes and to biotechnology and therapy. Many ribonucleases, ribozymes, and non-biological catalysts function via acid-base catalysis of an intramolecular transesterification mechanism in which the 2'-OH group attacks the adjacent phosphate group. The pentacoordinated phosphorane intermediate may collapse back to starting material, or yield isomerized or cleaved products.

  17. The influence of solid/liquid separation techniques on the sugar yield in two-step dilute acid hydrolysis of softwood followed by enzymatic hydrolysis

    Directory of Open Access Journals (Sweden)

    Galbe Mats

    2009-03-01

    Full Text Available Abstract Background Two-step dilute acid hydrolysis of softwood, either as a stand-alone process or as pretreatment before enzymatic hydrolysis, is considered to result in higher sugar yields than one-step acid hydrolysis. However, this requires removal of the liquid between the two steps. In an industrial process, filtration and washing of the material between the two steps is difficult, as it should be performed at high pressure to reduce energy demand. Moreover, the application of pressure leads to more compact solids, which may affect subsequent processing steps. This study was carried out to investigate the influence of pressing the biomass, in combination with the effects of not washing the material, on the sugar yield obtained from two-step dilute acid hydrolysis, with and without subsequent enzymatic digestion of the solids. Results Washing the material between the two acid hydrolysis steps, followed by enzymatic digestion, resulted in recovery of 96% of the mannose and 81% of the glucose (% of the theoretical in the liquid fraction, regardless of the choice of dewatering method (pressing or vacuum filtration. Not washing the solids between the two acid hydrolysis steps led to elevated acidity of the remaining solids during the second hydrolysis step, which resulted in lower yields of mannose, 85% and 74% of the theoretical, for the pressed and vacuum-filtered slurry, respectively, due to sugar degradation. However, this increase in acidity resulted in a higher glucose yield (94.2% from pressed slurry than from filtered slurry (77.6%. Conclusion Pressing the washed material between the two acid hydrolysis steps had no significant negative effect on the sugar yields of the second acid hydrolysis step or on enzymatic hydrolysis. Not washing the material resulted in a harsher second acid hydrolysis step, which caused greater degradation of the sugars during subsequent acid hydrolysis of the solids, particularly in case of the vacuum

  18. On the Brønsted acid-catalyzed homogeneous hydrolysis of furans.

    Science.gov (United States)

    Nikbin, Nima; Caratzoulas, Stavros; Vlachos, Dionisios G

    2013-11-01

    Furan affairs: Electronic structure calculations of the homogeneous Brønsted acid-catalyzed hydrolysis of 2,5-dimethylfuran show that proton transfer to the β-position is rate-limiting and provides support that the hydrolysis follows general acid catalysis. By means of projected Fukui indices, we show this to be the case for unsubstituted, 2-, and 2,5-substituted furans with electron-donating groups.

  19. Acid and enzymatic hydrolysis to recover reducing sugars from cassava bagasse: an economic study

    Directory of Open Access Journals (Sweden)

    Woiciechowski Adenise Lorenci

    2002-01-01

    Full Text Available The objective of this work was to study the acid and enzymatic hydrolysis of cassava bagasse for the recovery of reducing sugars and to establish the operational costs. A statistical program "Statistica", based on the surface response was used to optimize the recovery of reducing sugars in both the processes. The process economics was determined considering the values of reducing sugars obtained at laboratory scale, and the operations costs of a cylindrical reactor of 1500 L, with flat walls at the top and bottom. The reactor was operated with 150 kg of cassava bagasse and 1350 kg of water. The yield of the acid hydrolysis was 62.4 g of reducing sugars from 100 g of cassava bagasse containing 66% starch. It represented 94.5% of reducing sugar recovery. The yield of the enzymatic hydrolysis was 77.1 g of reducing sugars from 120 g of cassava bagasse, which represented 97.3% of reducing sugars recovery. Concerning to the time, a batch of acid hydrolysis required 10 minutes, plus the time to heat and cool the reactor, and a batch of the enzymatic hydrolysis needed 25 hours and 20 minutes, plus the time to heat and to cool the reactor. Thus, the acid hydrolysis of 150 kg of cassava bagasse required US$ 34.27, and the enzymatic hydrolysis of the same amount of cassava bagasse required US$ 2470.99.

  20. Acid hydrolysis of corn stover using hydrochloric acid: Kinetic modeling and statistical optimization

    Directory of Open Access Journals (Sweden)

    Sun Yong

    2014-01-01

    Full Text Available The hydrolysis of corn stover using hydrochloric acid was studied. The kinetic parameters of the mathematical models for predicting the yields of xylose, glucose, furfural and acetic acid were obtained, and the corresponding xylose generation activation energy of 100 kJ/mol was determined. The characterization of corn stover using with different techniques during hydrolysis indicated an effective removal of xylan and the slightly alteration on the structures of cellulose and lignin. A 23five levels Central Composite Design (CCD was used to develop a statistical model for the optimization of process variables including acid concentration, pretreatment temperature and time. The optimum conditions determined by this model were found to be 108ºC for 80 minutes with acid concentration of 5.8%. Under these conditions, the maximised results are the following: xylose 19.93 g/L, glucose 1.2 g/L, furfural 1.5 g/L, acetic acid 1.3 g/L. The validation of the model indicates a good agreement between the experimental results and the predicted values.

  1. Enhanced xylose recovery from oil palm empty fruit bunch by efficient acid hydrolysis.

    Science.gov (United States)

    Tan, Hooi Teng; Dykes, Gary A; Wu, Ta Yeong; Siow, Lee Fong

    2013-08-01

    Oil palm empty fruit bunch (EFB) is abundantly available in Malaysia and it is a potential source of xylose for the production of high-value added products. This study aimed to optimize the hydrolysis of EFB using dilute sulfuric acid (H2SO4) and phosphoric acid (H3PO4) via response surface methodology for maximum xylose recovery. Hydrolysis was carried out in an autoclave. An optimum xylose yield of 91.2 % was obtained at 116 °C using 2.0 % (v/v) H2SO4, a solid/liquid ratio of 1:5 and a hydrolysis time of 20 min. A lower optimum xylose yield of 24.0 % was observed for dilute H3PO4 hydrolysis at 116 °C using 2.4 % (v/v) H3PO4, a solid/liquid ratio of 1:5 and a hydrolysis time of 20 min. The optimized hydrolysis conditions suggested that EFB hydrolysis by H2SO4 resulted in a higher xylose yield at a lower acid concentration as compared to H3PO4.

  2. Solid Acid-Catalyzed Cellulose Hydrolysis Monitored by In Situ ATR-IR Spectroscopy

    NARCIS (Netherlands)

    Zakzeski, J.|info:eu-repo/dai/nl/326160256; Grisel, R.J.H.; Smit, A.T.; Weckhuysen, B.M.|info:eu-repo/dai/nl/285484397

    2012-01-01

    The solid acid-catalyzed hydrolysis of cellulose was studied under elevated temperatures and autogenous pressures using in situ ATR-IR spectroscopy. Standards of cellulose and pure reaction products, which include glucose, fructose, hydroxymethylfurfural (HMF), levulinic acid (LA), formic acid, and

  3. Developmental Transition from Enzymatic to Acid Hydrolysis of Sucrose in Acid Limes (Citrus aurantifolia) 1

    Science.gov (United States)

    Echeverria, Ed

    1990-01-01

    The sucrose breakdown mechanisms in juice sacs of acid lime (Citrus aurantifolia [Christm.] Swing.) were investigated throughout fruit development. All three enzymes of sucrose catabolism (sucrose synthase, acid, and alkaline invertase) are present during the initial stages. The activities of these enzymes declined rapidly and disappeared by stage 5 (80% development) but not before vacuolar pH had decreased to approximately 2.5. At this stage, sucrose breakdown occurs by acid hydrolysis. By attaining a vacuolar pH of 2.5 prior to enzyme disappearance, the cell maintains a continuous ability to break down sucrose throughout ontogeny. Thus, acid limes possess a unique and coordinated system for sucrose breakdown that involves both enzymatic and nonenzymatic pathways. PMID:16667241

  4. Developmental Transition from Enzymatic to Acid Hydrolysis of Sucrose in Acid Limes (Citrus aurantifolia).

    Science.gov (United States)

    Echeverria, E

    1990-01-01

    The sucrose breakdown mechanisms in juice sacs of acid lime (Citrus aurantifolia [Christm.] Swing.) were investigated throughout fruit development. All three enzymes of sucrose catabolism (sucrose synthase, acid, and alkaline invertase) are present during the initial stages. The activities of these enzymes declined rapidly and disappeared by stage 5 (80% development) but not before vacuolar pH had decreased to approximately 2.5. At this stage, sucrose breakdown occurs by acid hydrolysis. By attaining a vacuolar pH of 2.5 prior to enzyme disappearance, the cell maintains a continuous ability to break down sucrose throughout ontogeny. Thus, acid limes possess a unique and coordinated system for sucrose breakdown that involves both enzymatic and nonenzymatic pathways.

  5. Obtaining fermentable sugars by dilute acid hydrolysis of hemicellulose and fast pyrolysis of cellulose.

    Science.gov (United States)

    Jiang, Liqun; Zheng, Anqing; Zhao, Zengli; He, Fang; Li, Haibin; Liu, Weiguo

    2015-04-01

    The objective of this study was to get fermentable sugars by dilute acid hydrolysis of hemicellulose and fast pyrolysis of cellulose from sugarcane bagasse. Hemicellulose could be easily hydrolyzed by dilute acid as sugars. The remained solid residue of acid hydrolysis was utilized to get levoglucosan by fast pyrolysis economically. Levoglucosan yield from crystalline cellulose could be as high as 61.47%. Dilute acid hydrolysis was also a promising pretreatment for levoglucosan production from lignocellulose. The dilute acid pretreated sugarcane bagasse resulted in higher levoglucosan yield (40.50%) in fast pyrolysis by micropyrolyzer, which was more effective than water washed (29.10%) and un-pretreated (12.84%). It was mainly ascribed to the effective removal of alkali and alkaline earth metals and the accumulation of crystalline cellulose. This strategy seems a promising route to achieve inexpensive fermentable sugars from lignocellulose for biorefinery. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Identification of Cultured and Natural Astragalus Root Based on Monosaccharide Mapping

    Directory of Open Access Journals (Sweden)

    Ke Li

    2015-09-01

    Full Text Available As the main substances responsible for immunomodulatory activity, saccharides can be used as quality indicators for Astragalus root (RA. Saccharide content is commonly determined by ultraviolet spectroscopy, which lacks species specificity and has not been applied in the Chinese Pharmacopoeia. Monosaccharide mapping based on trifluoroacetic acid (TFA hydrolysis can be used for quantitative analysis of saccharide compositions. In addition, species specificity can be evaluated by analysis of the mapping characteristics. In this study, monosaccharide mapping of soluble saccharides in the cytoplasm and polysaccharides in the cell wall of 24 batches of RA samples with different growth patterns were obtained based on TFA hydrolysis followed by gas chromatography-mass spectrometry. Results indicated that the mapping and the molar ratios of saccharide compositions of the cultured and natural RA samples were different for both cytoplasm and cell wall. For example, the molar ratio of mannose and arabinose was more than 3.5:1 in cytoplasm in cultured RA, whereas the ratio was less than 3.5:1 in natural RA. This research not only lays a foundation for screening indicators for RA, but also provided new ways of evaluating the quality of Chinese medicinal materials in which saccharides are the main bioactive substances.

  7. Comparison of sulfuric and hydrochloric acids as catalysts in hydrolysis of Kappaphycus alvarezii (cottonii).

    Science.gov (United States)

    Meinita, Maria Dyah Nur; Hong, Yong-Ki; Jeong, Gwi-Taek

    2012-01-01

    In this study, hydrolysis of marine algal biomass Kappaphhycus alvarezii using two different acid catalysts was examined with the goal of identifying optimal reaction conditions for the formation of sugars and by-products. K. alvarezii were hydrolyzed by autoclave using sulfuric acid or hydrochloric acid as catalyst with different acid concentrations (0.1-1.0 M), substrate concentrations (1.0-13.5%), hydrolysis time (10-90 min) and hydrolysis temperatures (100-130 (°)C). A difference in galactose, glucose, reducing sugar and total sugar content was observed under the different hydrolysis conditions. Different by-product compounds such as 5-hydroxymethylfurfural and levulinic acid were also observed under the different reaction conditions. The optimal conditions for hydrolysis were achieved at a sulfuric acid concentration, temperature and reaction time of 0.2 M, 130 °C and 15 min, respectively. These results may provide useful information for the development of more efficient systems for biofuel production from marine biomass.

  8. Experimental and kinetic modelling studies on the acid-catalysed hydrolysis of the water hyacinth plant to levulinic acid

    NARCIS (Netherlands)

    Girisuta, B.; Danon, B.; Manurung, R.; Janssen, L. P. B. M.; Heeres, H. J.

    2008-01-01

    A comprehensive experimental and modelling study on the acid-catalysed hydrolysis of the water hyacinth plant (Eichhornia crassipes) to optimise the yield of levulinic acid (LA) is reported (T = 150-175 degrees C, C-H2SO4 - 0.1-1 M, water hyacinth intake = 1-5 wt%). At high acid concentrations (> 0.

  9. Effect of defatting on acid hydrolysis rate of maize starch with different amylose contents.

    Science.gov (United States)

    Wei, Benxi; Hu, Xiuting; Zhang, Bao; Li, Hongyan; Xu, Xueming; Jin, Zhengyu; Tian, Yaoqi

    2013-11-01

    The effect of defatting on the physiochemical properties and the acid hydrolysis rate of maize starch with different amylose contents was evaluated in this study. The increase in the number of pores and the stripping of starch surface layers were observed after defatting by scanning electron microscopy. X-ray diffraction spectrum showed that the peaks attributing to the amylose-lipid complex disappeared. The relative crystallinity increased by 19% for high-amylose maize starch (HMS) on defatting, while the other tested starches virtually unchanged. Differential scanning calorimetry study indicated an increase in the thermal stability for the defatted starches. Compared with native waxy maize starch, the acid hydrolysis rate of the defatted one increased by 6% after 10 days. For normal maize starch (NMS) and HMS, the higher rate of hydrolysis was observed during the first 5 days. Thereafter, the hydrolysis rate was lower than that of their native counterpart. The increase in susceptibility to acid hydrolysis (in the first 5 days) was mainly attributed to the defective and porous structures formed during defatting process, while the decrease of hydrolysis rate for NMS and HMS samples (after the first 5 days) probably resulted from the increase in the relative crystallinity.

  10. High-yield production of biosugars from Gracilaria verrucosa by acid and enzymatic hydrolysis processes.

    Science.gov (United States)

    Kim, Se Won; Hong, Chae-Hwan; Jeon, Sung-Wan; Shin, Hyun-Jae

    2015-11-01

    Gracilaria verrucosa, the red alga, is a suitable feedstock for biosugar production. This study analyzes biosugar production by the hydrolysis of G. verrucosa conducted under various conditions (i.e., various acid concentrations, substrate concentrations, reaction times, and enzyme dosages). The acid hydrolysates of G. verrucosa yielded a total of 7.47g/L (37.4%) and 10.63g/L (21.26%) of reducing sugars under optimal small (30mL) and large laboratory-scale (1L) hydrolysis processes, respectively. Reducing sugar obtained from acid and enzymatic hydrolysates were 10% higher, with minimum by-products, than those reported in other studies. The mass balance for the small laboratory-scale process showed that the acid and enzymatic hydrolysates had a carbohydrate conversion of 57.2%. The mass balance approach to the entire hydrolysis process of red seaweed for biosugar production can be applied to other saccharification processes.

  11. Trichloroisocyanuric acid (TCCA): an efficient green reagent for activation of thioglycosides toward hydrolysis.

    Science.gov (United States)

    Basu, Nabamita; Maity, Sajal Kumar; Chaudhury, Aritra; Ghosh, Rina

    2013-03-22

    Trichloroisocyanuric acid (TCCA), an inexpensive, commercially available, and non-toxic reagent has been used for the activation of thioglycosides toward their hydrolysis to the corresponding hemiacetals in high to excellent yields. The methodology provides a mild reaction condition for dealing with compounds containing acid sensitive functional groups.

  12. Effect of Varying Acid Hydrolysis Condition in Gracilaria Sp. Fermentation Using Sasad

    Science.gov (United States)

    Mansuit, H.; Samsuri, M. D. C.; Sipaut, C. S.; Yee, C. F.; Yasir, S. M.; Mansa, R.

    2015-04-01

    Macroalgae or seaweed is being considered as promising feedstock for bioalcohol production due to high polysaccharides content. Polysaccharides can be converted into fermentable sugar through acid hydrolysis pre-treatment. In this study, the potential of using carbohydrate-rich macroalgae, Gracilaria sp. as feedstock for bioalcohol production via various acid hydrolysis conditions prior to the fermentation process was investigated and evaluated. The seaweed used in this research was from the red algae group, using species of Gracilaria sp. which was collected from Sg. Petani Kedah, Malaysia. Pre-treatment of substrate was done using H2SO4 and HCl with molarity ranging from 0.2M to 0.8M. The pretreatment time were varied in the range of 15 to 30 minutes. Fermentation was conducted using Sasad, a local Sabahan fermentation agent as a starter culture. Alcohol extraction was done using a distillation unit. Reducing sugar analysis was done by Benedict test method. Alcohol content analysis was done using specific gravity test. After hydrolysis, it was found out that acid hydrolysis at 0.2M H2SO4 and pre-treated for 20 minutes at 121°C has shown the highest reducing sugar content which has yield (10.06 mg/g) of reducing sugar. It was followed by other samples hydrolysis using 0.4M HCl with 30 minutes pre-treatment and 0.2M H2SO4, 15 minutes pre-treatment with yield of 8.06 mg/g and 5.75 mg/g reducing sugar content respectively. In conclusion, acid hydrolysis of Gracilaria sp. can produce higher reducing sugar yield and thus it can further enhance the bioalcohol production yield. Hence, acid hydrolysis of Gracilaria sp. should be studied more as it is an important step in the bioalcohol production and upscaling process.

  13. Combined heat treatment and acid hydrolysis of cassava grate waste (CGW) biomass for ethanol production

    Energy Technology Data Exchange (ETDEWEB)

    Agu, R.C.; Amadife, A.E.; Ude, C.M.; Onyia, A.; Ogu, E.O. [Enugu State Univ. of Science and Technology (Nigeria). Faculty of Applied Natural Sciences; Okafor, M.; Ezejiofor, E. [Nnamdi Azikiwe Univ., Awka (Nigeria). Dept. of Applied Microbiology

    1997-12-31

    The effect of combined heat treatment and acid hydrolysis (various concentrations) on cassava grate waste (CGW) biomass for ethanol production was investigated. At high concentrations of H{sub 2}SO{sub 4} (1--5 M), hydrolysis of the CGW biomass was achieved but with excessive charring or dehydration reaction. At lower acid concentrations, hydrolysis of CGW biomass was also achieved with 0.3--0.5 M H{sub 2}SO{sub 4}, while partial hydrolysis was obtained below 0.3 M H{sub 2}SO{sub 4} (the lowest acid concentration that hydrolyzed CGW biomass) at 120 C and 1 atm pressure for 30 min. A 60% process efficiency was achieved with 0.3 M H{sub 2}SO{sub 4} in hydrolyzing the cellulose and lignin materials present in the CGW biomass. High acid concentration is therefore not required for CGW biomass hydrolysis. The low acid concentration required for CGW biomass hydrolysis, as well as the minimal cost required for detoxification of CGW biomass because of low hydrogen cyanide content of CGW biomass would seem to make this process very economical. From three liters of the CGW biomass hydrolysate obtained from hydrolysis with 0.3M H{sub 2}SO{sub 4}, ethanol yield was 3.5 (v/v%) after yeast fermentation. However, although the process resulted in gainful utilization of CGW biomass, additional costs would be required to effectively dispose new by-products generated from CGW biomass processing.

  14. Effect of Mild Acid Hydrolysis Parameters on Properties of Microcrystalline Cellulose

    Directory of Open Access Journals (Sweden)

    Kari Mikael Vanhatalo

    2014-06-01

    Full Text Available The effects of mild kraft pulp hydrolysis conditions (reaction time, temperature, pulp consistency, and acid dosage with sulfuric acid (H2SO4 on the properties of microcrystalline cellulose (MCC were investigated. The degree of polymerization (DP of cellulose rapidly decreased at the initiation of hydrolysis and leveled off after a certain reaction time, depending on the hydrolysis conditions. The intensity of the hydrolysis treatment greatly affected the cellulose particle size. Compared to the intensive treatment, the mild conditions resulted in a broader particle size distribution, while smaller particles with a narrow size distribution were obtained under severe conditions. However, the particle size leveled off at a hydrolysis factor (P-factor of 300. The results suggest that after a certain P-factor (300, severe hydrolysis conditions have no advantage over mild ones as related to the MCC particle properties. Because of favourable reaction conditions (short delay time, moderate temperature, and small amounts of chemicals, this method can be implemented on an industrial scale in a chemical pulp mill.

  15. Production and effect of aldonic acids during enzymatic hydrolysis of lignocellulose at high dry matter content

    DEFF Research Database (Denmark)

    Cannella, David; Hsieh, Chia-Wen; Felby, Claus;

    2012-01-01

    conversion yields. When using pure cellulose substrates it has been determined that both oxidized and unoxidized cellodextrin products are formed. We report the effect of oxidative activity in a commercial enzyme mix (Cellic CTec2) upon overall hydrolysis, formation of oxidized products and impact on ß......-glucosidase than glucose. The formation of oxidized products decreased as the hydrolysis temperature was increased from 33° to 50°C. Despite end-product inhibition, the oxidative cleavage of the cellulose chains has a synergistic effect upon the overall hydrolysis of cellulose as the sugar yield increased compared...... hydrolysis of pretreated wheat straw at 30% WIS. Up to 4% of released glucose was oxidized into gluconic acid using Cellic CTec2, whereas no oxidized products were detected when using an earlier cellulase preparation Celluclast/Novozym188. However, the cellulose conversion yield was 25% lower using...

  16. Comparison of aqueous ammonia and dilute acid pretreatment of bamboo fractions: Structure properties and enzymatic hydrolysis.

    Science.gov (United States)

    Xin, Donglin; Yang, Zhong; Liu, Feng; Xu, Xueru; Zhang, Junhua

    2015-01-01

    The effect of two pretreatments methods, aqueous ammonia (SAA) and dilute acid (DA), on the chemical compositions, cellulose crystallinity, morphologic change, and enzymatic hydrolysis of bamboo fractions (bamboo yellow, timber, green, and knot) was compared. Bamboo fractions with SAA pretreatment had better hydrolysability than those with DA pretreatment. High crystallinity index resulted in low hydrolysis yield in the conversion of SAA pretreated bamboo fractions, not DA pretreated fractions. The increase of cellulase loading had modestly positive effect in the hydrolysis of both SAA and DA pretreated bamboo fractions, while supplement of xylanase significantly increased the hydrolysis of the pretreated bamboo fractions, especially after SAA pretreatment. The results indicated that SAA pretreatment was more effective than DA pretreatment in conversion of bamboo fractions, and supplementation of xylanase was necessary in effective conversion of the SAA pretreated fractions into fermentable sugars.

  17. MODELLING AND OPTIMISATION OF DILUTE ACID HYDROLYSIS OF CORN STOVER USING BOX-BEHNKEN DESIGN

    Directory of Open Access Journals (Sweden)

    AMENAGHAWON NOSAKHARE ANDREW

    2014-08-01

    Full Text Available Response surface methodology (RSM was employed for the analysis of the simultaneous effect of acid concentration, hydrolysis time and temperature on the total reducing sugar concentration obtained during acid hydrolysis of corn stover. A three-variable, three-level Box-Behnken design (BBD was used to develop a statistical model for the optimisation of the process variables. The optimal hydrolysis conditions that resulted in the maximum total reducing sugar concentration were acid concentration; 1.72% (w/w, temperature; 169.260C and pretreatment time; 48.73 minutes. Under these conditions, the total reducing sugar concentration was obtained to be 23.41g/L. Validation of the model indicated no difference between predicted and observed values.

  18. Efficient production of glucose by microwave-assisted acid hydrolysis of cellulose hydrogel.

    Science.gov (United States)

    Sun, Binzhe; Duan, Lian; Peng, Gege; Li, Xiaoxia; Xu, Aihua

    2015-09-01

    To improve the production of glucose from cellulose, a simple and effective route was developed. This process uses a combination of a step of cellulose dissolution in aqueous NaOH/urea solution and then regeneration with water, followed by an acid hydrolysis step under microwave irradiation. The method is effective to obtain glucose from α-cellulose, microcrystalline cellulose, filter paper, ramie fiber and absorbent cotton. Increased with the acid concentration the glucose yield from hydrogel hydrolysis increased from 0.42% to 44.6% at 160 °C for 10 min. Moreover, the ozone treatment of cellulose in NaOH/urea solution before regeneration significantly enhanced the hydrolysis efficiency with a glucose yield of 59.1%. It is believed that the chains in cellulose hydrogel are relatively free approached, making that the acids easily access the β-glycosidic bonds. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Production and effect of aldonic acids during enzymatic hydrolysis of lignocellulose at high dry matter content

    DEFF Research Database (Denmark)

    Cannella, David; Hsieh, Chia-Wen; Felby, Claus

    2012-01-01

    hydrolysis of pretreated wheat straw at 30% WIS. Up to 4% of released glucose was oxidized into gluconic acid using Cellic CTec2, whereas no oxidized products were detected when using an earlier cellulase preparation Celluclast/Novozym188. However, the cellulose conversion yield was 25% lower using......, no reducing agent was needed for the function of the oxidative enzymes. Conclusions: The presence of oxidative enzymes in Cellic CTec2 led to the formation of cellobionic and gluconic acid during hydrolysis of pretreated wheat straw and filter paper. Gluconic acid was a stronger inhibitor of ß......Abstract Background: The recent discovery of accessory proteins that boost cellulose hydrolysis has increased the economical and technical efficiency of processing cellulose to bioethanol. Oxidative enzymes (e.g. GH61) present in new commercial enzyme preparations have shown to increase cellulose...

  20. Ruminal bacteria and protozoa composition, digestibility, and amino acid profile determined by multiple hydrolysis times.

    Science.gov (United States)

    Fessenden, S W; Hackmann, T J; Ross, D A; Foskolos, A; Van Amburgh, M E

    2017-09-01

    Microbial samples from 4 independent experiments in lactating dairy cattle were obtained and analyzed for nutrient composition, AA digestibility, and AA profile after multiple hydrolysis times ranging from 2 to 168 h. Similar bacterial and protozoal isolation techniques were used for all isolations. Omasal bacteria and protozoa samples were analyzed for AA digestibility using a new in vitro technique. Multiple time point hydrolysis and least squares nonlinear regression were used to determine the AA content of omasal bacteria and protozoa, and equivalency comparisons were made against single time point hydrolysis. Formalin was used in 1 experiment, which negatively affected AA digestibility and likely limited the complete release of AA during acid hydrolysis. The mean AA digestibility was 87.8 and 81.6% for non-formalin-treated bacteria and protozoa, respectively. Preservation of microbe samples in formalin likely decreased recovery of several individual AA. Results from the multiple time point hydrolysis indicated that Ile, Val, and Met hydrolyzed at a slower rate compared with other essential AA. Singe time point hydrolysis was found to be nonequivalent to multiple time point hydrolysis when considering biologically important changes in estimated microbial AA profiles. Several AA, including Met, Ile, and Val, were underpredicted using AA determination after a single 24-h hydrolysis. Models for predicting postruminal supply of AA might need to consider potential bias present in postruminal AA flow literature when AA determinations are performed after single time point hydrolysis and when using formalin as a preservative for microbial samples. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  1. Acid hydrolysis of Curcuma longa residue for ethanol and lactic acid fermentation.

    Science.gov (United States)

    Nguyen, Cuong Mai; Nguyen, Thanh Ngoc; Choi, Gyung Ja; Choi, Yong Ho; Jang, Kyoung Soo; Park, Youn-Je; Kim, Jin-Cheol

    2014-01-01

    This research examines the acid hydrolysis of Curcuma longa waste, to obtain the hydrolysate containing lactic acid and ethanol fermentative sugars. A central composite design for describing regression equations of variables was used. The selected optimum condition was 4.91% sulphuric acid, 122.68°C and 50 min using the desirability function under the following conditions: the maximum reducing sugar (RS) yield is within the limited range of the 5-hydroxymethylfurfural (HMF) and furfural concentrations. Under the condition, the obtained solution contained 144 g RS/L, 0.79 g furfural/L and 2.59 g HMF/L and was directly fermented without a detoxification step. The maximum product concentration, average productivity, RS conversion and product yield were 115.36 g/L, 2.88 g/L/h, 89.43% and 64% for L-lactic acid; 113.92 g/L, 2.59 g/L/h, 88.31% and 63.29% for D-lactic acid; and 55.03 g/L, 1.38 g/L/h, 42.66 and 30.57%, respectively, for ethanol using a 7-L jar fermenter.

  2. Sub-critical water hydrolysis of hog hair for amino acid production.

    Science.gov (United States)

    Esteban, M B; García, A J; Ramos, P; Márquez, M C

    2010-04-01

    A recycling method using sub-critical water hydrolysis to convert hog hair from slaughterhouses into amino acids was developed. The influence of the reaction parameters such as temperature, time of reaction and initial substrate concentration were investigated in a batch reactor. The quality and quantity of amino acids in hydrolysates were determined and 17 kinds of amino acids were obtained. Under the tested conditions, the highest amino acid yield (325 mg/g protein) was reached at an initial substrate concentration of 10 g/l, a temperature of 250 degrees C and a reaction time of 60 min. A large amount of low-molecular weight amino acids, such alanine and glycine, was observed at these operating conditions. Sub-critical water hydrolysis was confirmed as an effective and practical process to recover amino acids from hog hair waste.

  3. SO₃H-functionalized acidic ionic liquids as catalysts for the hydrolysis of cellulose.

    Science.gov (United States)

    Liu, Yuanyuan; Xiao, Wenwen; Xia, Shuqian; Ma, Peisheng

    2013-01-30

    The conversion of cellulose into valuable chemicals to deal with the depletion of fossil fuel has got much attention. Completing the hydrolysis of cellulose under mild conditions is the key step. In this study, six kinds of SO(3)H-functionalized acidic ionic liquids were used as acid catalyst to promote the hydrolysis of cellulose in 1-butyl-3-methylimidazolium chloride ([BMIM]Cl). All of them were efficient for the hydrolysis of cellulose, with the maximum total reducing sugars (TRS) yields over 83% at 100 °C. Acidic ionic liquids with analogous structures showed similar catalytic activities. Triethyl-(3-sulfo-propyl)-ammonium hydrogen sulfate (IL-5 in this study) was the optimum ionic liquid for cellulose hydrolysis, with the maximum TRS yield at 100 °C up to 99% when the dosage used was 0.2g. In addition, the water in [BMIM]Cl had negative effect on cellulose hydrolysis. Therefore, controlling the content of water in a comparatively low level is quite necessary. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Humic Acid-Like and Fulvic Acid-Like Inhibition on the Hydrolysis of Cellulose and Tributyrin

    NARCIS (Netherlands)

    Fernandes, T.V.; Lier, van J.B.; Zeeman, Grietje

    2015-01-01

    Enzymatic hydrolysis of complex wastes is a critical step for efficient biogas production in anaerobic digesters. Inhibition of this hydrolytic step was studied by addition of humic acid-like (HAL) and fulvic acid-like (FAL) substances, extracted from maize silage and fresh cow manure, to batch

  5. Humic Acid-Like and Fulvic Acid-Like Inhibition on the Hydrolysis of Cellulose and Tributyrin

    NARCIS (Netherlands)

    Fernandes, Tania V.; van Lier, Jules B.; Zeeman, Grietje

    2015-01-01

    Enzymatic hydrolysis of complex wastes is a critical step for efficient biogas production in anaerobic digesters. Inhibition of this hydrolytic step was studied by addition of humic acid-like (HAL) and fulvic acid-like (FAL) substances, extracted from maize silage and fresh cow manure, to batch

  6. Production and effect of aldonic acids during enzymatic hydrolysis of lignocellulose at high dry matter content

    Directory of Open Access Journals (Sweden)

    Cannella David

    2012-04-01

    Full Text Available Abstract Background The recent discovery of accessory proteins that boost cellulose hydrolysis has increased the economical and technical efficiency of processing cellulose to bioethanol. Oxidative enzymes (e.g. GH61 present in new commercial enzyme preparations have shown to increase cellulose conversion yields. When using pure cellulose substrates it has been determined that both oxidized and unoxidized cellodextrin products are formed. We report the effect of oxidative activity in a commercial enzyme mix (Cellic CTec2 upon overall hydrolysis, formation of oxidized products and impact on β-glucosidase activity. The experiments were done at high solids loadings using a lignocellulosic substrate simulating commercially relevant conditions. Results The Cellic CTec2 contained oxidative enzymes which produce gluconic acid from lignocellulose. Both gluconic and cellobionic acid were produced during hydrolysis of pretreated wheat straw at 30% WIS. Up to 4% of released glucose was oxidized into gluconic acid using Cellic CTec2, whereas no oxidized products were detected when using an earlier cellulase preparation Celluclast/Novozym188. However, the cellulose conversion yield was 25% lower using Celluclast/Novozym188 compared to Cellic CTec2. Despite the advantage of the oxidative enzymes, it was shown that aldonic acids could be problematic to the hydrolytic enzymes. Hydrolysis experiments revealed that cellobionic acid was hydrolyzed by β-glucosidase at a rate almost 10-fold lower than for cellobiose, and the formed gluconic acid was an inhibitor of the β-glucosidase. Interestingly, the level of gluconic acid varied significantly with temperature. At 50°C (SHF conditions 35% less gluconic acid was produced compared to at 33°C (SSF conditions. We also found that in the presence of lignin, no reducing agent was needed for the function of the oxidative enzymes. Conclusions The presence of oxidative enzymes in Cellic CTec2 led to the formation of

  7. Production and effect of aldonic acids during enzymatic hydrolysis of lignocellulose at high dry matter content.

    Science.gov (United States)

    Cannella, David; Hsieh, Chia-Wen C; Felby, Claus; Jørgensen, Henning

    2012-04-30

    The recent discovery of accessory proteins that boost cellulose hydrolysis has increased the economical and technical efficiency of processing cellulose to bioethanol. Oxidative enzymes (e.g. GH61) present in new commercial enzyme preparations have shown to increase cellulose conversion yields. When using pure cellulose substrates it has been determined that both oxidized and unoxidized cellodextrin products are formed. We report the effect of oxidative activity in a commercial enzyme mix (Cellic CTec2) upon overall hydrolysis, formation of oxidized products and impact on β-glucosidase activity. The experiments were done at high solids loadings using a lignocellulosic substrate simulating commercially relevant conditions. The Cellic CTec2 contained oxidative enzymes which produce gluconic acid from lignocellulose. Both gluconic and cellobionic acid were produced during hydrolysis of pretreated wheat straw at 30% WIS. Up to 4% of released glucose was oxidized into gluconic acid using Cellic CTec2, whereas no oxidized products were detected when using an earlier cellulase preparation Celluclast/Novozym188. However, the cellulose conversion yield was 25% lower using Celluclast/Novozym188 compared to Cellic CTec2. Despite the advantage of the oxidative enzymes, it was shown that aldonic acids could be problematic to the hydrolytic enzymes. Hydrolysis experiments revealed that cellobionic acid was hydrolyzed by β-glucosidase at a rate almost 10-fold lower than for cellobiose, and the formed gluconic acid was an inhibitor of the β-glucosidase.Interestingly, the level of gluconic acid varied significantly with temperature. At 50°C (SHF conditions) 35% less gluconic acid was produced compared to at 33°C (SSF conditions). We also found that in the presence of lignin, no reducing agent was needed for the function of the oxidative enzymes. The presence of oxidative enzymes in Cellic CTec2 led to the formation of cellobionic and gluconic acid during hydrolysis of

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

    Science.gov (United States)

    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.

  9. Production of reducing sugar from oil palm empty fruit bunch (EFB cellulose fibres via acid hydrolysis

    Directory of Open Access Journals (Sweden)

    Siew Xian Chin

    2013-02-01

    Full Text Available Cellulosic fibre of oil palm empty fruit bunches (EFB were used as a raw material for acid hydrolysis using mineral acids (H2SO4 and HCl to produce reducing sugar at moderate temperature and atmospheric pressure. Experiments were carried out to investigate the effect of the hydrolysis parameters, including acid concentration, temperature, and reaction time, on the total reducing sugar (TRS yield with the aid of response surface methodology (RSM. The preliminary hydrolysis studies of the EFB fibres showed that the presence of lignin in the fibres significantly affected the TRS yield. The maximum predicted TRS yield using H2SO4 was 30.61% under optimal conditions: acid concentration of 5 N, temperature of 139.65 oC, and reaction time of 4.16 h. For the hydrolysis using HCl, the maximum predicted TRS yield is 39.81% under optimal conditions: acid concentration of 4.63 N, temperature of 133.7 oC, reaction time of 2.05 h.

  10. Preparation of Slowly Digestible Starch by Citric Acid-hydrolysis with Autoclaving

    Directory of Open Access Journals (Sweden)

    Hansong Yu

    2015-03-01

    Full Text Available Aim of study is to produce Slowly Digestible Starch (SDS by a combination of citric acid-hydrolysis and autoclaving from raw corn starch. The effects of citric acid concentration, acid hydrolysis time, temperature and refrigeration and retro gradation time on the formation of SDS were investigated. The optimal process conditions optimized by Box-Benhnken’s central composite design and response surface analysis was as follows: concentration of citric acid is 0.08 M, acid hydrolyzed at 116°C for 14.5 min, and then stored at 0°C for 72 h. Under these optimal conditions, the content of SDS peaked at 19.38%.

  11. Acid hydrolysis of cellulosic fibres: Comparison of bleached kraft pulp, dissolving pulps and cotton textile cellulose.

    Science.gov (United States)

    Palme, Anna; Theliander, Hans; Brelid, Harald

    2016-01-20

    The behaviour of different cellulosic fibres during acid hydrolysis has been investigated and the levelling-off degree of polymerisation (LODP) has been determined. The study included a bleached kraft pulp (both never-dried and once-dried) and two dissolving pulps (once-dried). Additionally, cotton cellulose from new cotton sheets and sheets discarded after long-time use was studied. Experimental results from the investigation, together with results found in literature, imply that ultrastructural differences between different fibres affect their susceptibility towards acid hydrolysis. Drying of a bleached kraft pulp was found to enhance the rate of acid hydrolysis and also result in a decrease in LODP. This implies that the susceptibility of cellulosic fibres towards acid hydrolysis is affected by drying-induced stresses in the cellulose chains. In cotton cellulose, it was found that use and laundering gave a substantial loss in the degree of polymerisation (DP), but that the LODP was only marginally affected. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  12. Monitoring the Hydrolysis of Olive Oil Catalyzed by Lipase via Acid Value Detection

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Hydrolysis of olive oil catalyzed by Candida lipolytica lipase was investigated. The relative concentration of the components in the product was determined by using high performance liquid chromatography(HPLC). Furthermore, a novel rapid method to detect the hydrolytic process of olive oil was developed based on the relationship between the acid value and the relative concentration of the different components.

  13. Facile synthesis of small crystal ZSM-5 zeolite by acid-catalyzed hydrolysis of tetraethylorthosilicate

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Small crystal zeolites ZSM-5 with sizes of 150-300 nm were synthesized using the colloidal silicate precursors as the silica source created by the acid-catalyzed hydrolysis of tetraethylorthosilicate with tetrapropylammonium bromide as the structure-directing agent within a short crystallization time of 20-35 h. The precursors and final products were detected by XRD, SEM, ICP and DLS.

  14. Catalytic conversion of carbohydrates to 5-hydroxymethylfurfural from the waste liquid of acid hydrolysis NCC.

    Science.gov (United States)

    Sun, Yonghui; Liu, Pengtao; Liu, Zhong

    2016-05-20

    The principal goal of this work was to reuse the carbohydrates and recycle sulfuric acid in the waste liquid of acid hydrolysis nanocrystalline cellulose (NCC). Therefore, in this work, the optimizations of further hydrolysis of waste liquid of acid hydrolysis NCC and catalytic conversion of L4 to 5-hydroxymethylfurfural (5-HMF) were studied. Sulfuric acid was separated by spiral wound diffusion dialysis (SWDD). The results revealed that cellulose can be hydrolyze to glucose absolutely under the condition of temperature 35 °C, 3 h, and sulfuric acid's concentration 62 wt%. And 78.3% sulfuric acid was recovered by SWDD. The yield of 5-HMF was highest in aqueous solution under the optimal condition was as follows, temperature 160 °C, 3 h, and sulfuric acid's concentration 12 wt%. Then the effect of biphasic solvent systems catalytic conversion and inorganic salt as additives were still examined. The results showed that both of them contributed to prepare 5-HMF. The yield and selectivity of 5-HMF was up to 21.0% and 31.4%, respectively. Copyright © 2016 Elsevier Ltd. All rights reserved.

  15. Starch conversion of ganyong (Canna edulis Ker. to bioethanol using acid hydrolysis and fermentation

    Directory of Open Access Journals (Sweden)

    LILY SURAYYA EKA PUTRI

    2008-04-01

    Full Text Available Starch of ganyong is one of the sources of ethanol which is able to be produced by acid hydrolysis and fermentation process. It had high concentration of carbohydrate that is 80%, so it could produce glucose highly within acid hydrolysis process. The result showed that the optimal amount of reducing sugar had been produced by nitrate acid 7% (dextrose equivalent, DE = 28.4. Nevertheless, type and concentration of acid had no significantly correlation to reducing sugar yielded. The total amount of glucose had correlation to amount of ethanol, in fermentation process. The optimal amount of ethanol was yielded from 4.81% of glucose and it produced about 4.84% ethanol. The more amount of glucose was yielded the more ethanol was produced. Controlling pH every 12 hours did not affected to production of ethanol significantly.

  16. Oxidation and hydrolysis of lactic acid in near-critical water

    Energy Technology Data Exchange (ETDEWEB)

    Li, L.; Vallejo, D.; Gloyna, E.F. [Univ. of Texas, Austin, TX (United States). Civil Engineering Dept.; Portela, J.R. [Univ. de Cadiz (Spain). Dept. de Ingenieria Quimica

    1999-07-01

    Hydrothermal reactions (oxidation and hydrolysis) involving lactic acid (LA) were studied at temperatures ranging from 300 to 400 C and a nominal pressure of 27.6 MPa. Kinetic models were developed with respect to concentrations of LA and total organic carbon (TOC), respectively. On the basis of identified liquid and gaseous products, pathways for hydrothermal reactions involving lactic acid were proposed. Acetic acid and acetaldehyde were confirmed as the major liquid intermediates for oxidation and hydrolysis reactions, respectively. Carbon monoxide and methane were identified as the major gaseous byproducts from these reactions. These results demonstrate the potential of completely oxidizing, as well as converting, lactic acid into other organic products, in high-temperature water.

  17. Lignin charcoal: byproduct of acid hydrolysis of eucalypt wood. [E. urophylla

    Energy Technology Data Exchange (ETDEWEB)

    Foelkel, C.E.B.; Zvinakevicius, C.; Carolino, J.M.; Pimenta, D.L.

    1981-01-01

    Studies are described in which wood of Eucalyptus urophylla was subjected to hydrolysis with sulphuric acid and the acidic or neutralized lignin residue was converted to charcoal in a laboratory oven with a nitrogen atmosphere. The lignin charcoal compared favourably with charcoal from eucalypt wood with regard to fixed carbon content and calorific capacity. Yield of charcoal from the lignin was about 53% based on the residue, or 15-16% based on the original amount of wood.

  18. Acid hydrolysis of native and annealed starches and branch-structure of their Naegeli dextrins.

    Science.gov (United States)

    Nakazawa, Yuta; Wang, Ya-Jane

    2003-11-21

    Eight commercial starches, including common corn, waxy corn, wheat, tapioca, potato, Hylon V, Hylon VII, and mung bean starch, were annealed by a multiple-step process, and their gelatinization characteristics were determined. Annealed starches had higher gelatinization temperatures, reduced gelatinization ranges, and increased gelatinization enthalpies than their native starches. The annealed starches with the highest gelatinization enthalpies were subjected to acid hydrolysis with 15.3% H2SO4, and Naegeli dextrins were prepared after 10 days' hydrolysis. Annealing increased the acid susceptibility of native starches in the first (rapid) and the second (slow) phases with potato starch showing the greatest and high amylose starches showing the least changes. Starches with a larger shift in onset gelatinization temperature also displayed a greater percent hydrolysis. The increase in susceptibility to acid hydrolysis was proposed to result from defective and porous structures that resulted after annealing. Although annealing perfected the crystalline structure, it also produced void space, which led to porous structures and possible starch granule defects. The molecular size distribution and chain length distribution of Naegeli dextrins of annealed and native starches were analyzed. The reorganization of the starch molecule during annealing occurred mainly within the crystalline lamellae. Imperfect double helices in the crystalline lamellae improved after annealing, and the branch linkages at the imperfect double helices became protected by the improved crystalline structure. Therefore, more long chains were observed in the Naegeli dextrins of annealed starches than in native starches.

  19. Cassava Pulp Hydrolysis under Microwave Irradiation with Oxalic Acid Catalyst for Ethanol Production

    Directory of Open Access Journals (Sweden)

    Euis Hermiati

    2014-07-01

    Full Text Available Microwave irradiation is an alternative method of starch hydrolysis that offers a rapid process. The aim of this research was to improve microwave-assisted hydrolysis of cassava pulp by using oxalic acid as a catalyst. Suspension of cassava pulp in 0.5% oxalic acid (1 g/20 mL was subjected to microwave irradiation at 140-230 °C for 5 minutes, with 4 minutes of pre-heating. One gram of fractured activated carbon made of coconut shell was added into a number of suspensions that were subjected to the same conditions of microwave irradiation. The soluble fraction of the hydrolysates was analyzed for its total soluble solids, malto-oligomer distribution, glucose content, pH value, and formation of brown compounds. The effects of the combined severity parameter at a substrate concentration of 5-12.5% on the glucose yield were also evaluated. The highest glucose yield (78% of dry matter was obtained after hydrolysis at 180 °C without activated carbon addition. Heating above 180 °C reduced the glucose yield and increased the pH and the formation of brown compounds. The use of activated carbon in microwave-assisted acid hydrolysis of cassava pulp reduced the glucose yield, but suppressed the formation of brown compounds. The highest glucose yield (70-80% of dry matter was attained at a severity parameter of 1.3-1.5.

  20. Acid Hydrolysis of Bromazepam Catalyzed by Micelles, Reverse Micelles, and Microemulsions

    Directory of Open Access Journals (Sweden)

    Ferdousi Begum

    2015-01-01

    Full Text Available Kinetics of the acid hydrolysis of bromazepam (Bz has been investigated in micelles, reverse micelles, and microemulcions of cetyltrimethylammonium bromide (CTAB by spectrophotometric method. The rate of the acid hydrolysis of Bz was found to be enhanced both below and above the critical micelle concentration (CMC of CTAB in aqueous solution. The pseudo-first-order rate constant (k′ shows an initial decrease for both low and high H+ concentrations. With further increase in [CTAB], at low [H+], the k′ attains an almost constant value, while, at high [H+], the k′ passes through a maximum and then decreases. The kinetic data for catalysis by micelles of CTAB was interpreted with the pseudophase ion exchange (PIE model. In CTAB/cyclohexane/1-butanol/water microemulsions, as the water to surfactant ratio (wo increases, the physicochemical properties and droplet sizes of microemulsions significantly change and distinct changes in reaction environment can be marked. The rate of the hydrolysis reaction exhibits excellent correlation with the physicochemical properties and droplet sizes of the microemulsions and reverse micelles of CTAB. At [H+] = 0.001 M, in reverse micelles and microemulsions of CTAB, the k′ of the acid hydrolysis of Bz decreases sharply followed by a slight increase with increasing wo.

  1. Solid acid-catalyzed cellulose hydrolysis monitored by in situ ATR-IR spectroscopy.

    Science.gov (United States)

    Zakzeski, Joseph; Grisel, Ruud J H; Smit, Arjan T; Weckhuysen, Bert M

    2012-02-13

    The solid acid-catalyzed hydrolysis of cellulose was studied under elevated temperatures and autogenous pressures using in situ ATR-IR spectroscopy. Standards of cellulose and pure reaction products, which include glucose, fructose, hydroxymethylfurfural (HMF), levulinic acid (LA), formic acid, and other compounds, were measured in water under ambient and elevated temperatures. A combination of spectroscopic and HPLC analysis revealed that the cellulose hydrolysis proceeds first through the disruption of the glycosidic linkages of cellulose to form smaller cellulose molecules, which are readily observed by their distinctive C-O vibrational stretches. The continued disruption of the linkages in these oligomers eventually results in the formation and accumulation of monomeric glucose. The solid-acid catalyst accelerated the isomerization of glucose to fructose, which then rapidly reacted under hydrothermal conditions to form degradation products, which included HMF, LA, formic acid, and acetic acid. The formation of these species could be suppressed by decreasing the residence time of glucose in the reactor, reaction temperature, and contact with the metal reactor. The hydrolysis of regenerated cellulose proceeded faster and under milder conditions than microcrystalline cellulose, which resulted in increased glucose yield and selectivity. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Powerful peracetic acid-ionic liquid pretreatment process for the efficient chemical hydrolysis of lignocellulosic biomass.

    Science.gov (United States)

    Uju; Goto, Masahiro; Kamiya, Noriho

    2016-08-01

    The aim of this work was to design a new method for the efficient saccharification of lignocellulosic biomass (LB) using a combination of peracetic acid (PAA) pretreatment with ionic liquid (IL)-HCl hydrolysis. The pretreatment of LBs with PAA disrupted the lignin fractions, enhanced the dissolution of LB and led to a significant increase in the initial rate of the IL-HCl hydrolysis. The pretreatment of Bagasse with PAA prior to its 1-buthyl-3-methylimidazolium chloride ([Bmim][Cl])-HCl hydrolysis, led to an improvement in the cellulose conversion from 20% to 70% in 1.5h. Interestingly, the 1-buthyl-3-methylpyridium chloride ([Bmpy][Cl])-HCl hydrolysis of Bagasse gave a cellulose conversion greater than 80%, with or without the PAA pretreatment. For LB derived from seaweed waste, the cellulose conversion reached 98% in 1h. The strong hydrolysis power of [Bmpy][Cl] was attributed to its ability to transform cellulose I to II, and lowering the degree of polymerization of cellulose.

  3. Effect of phosphoric acid pretreatment on enzymatic hydrolysis of microcrystalline cellulose.

    Science.gov (United States)

    Zhang, Juanhua; Zhang, Beixiao; Zhang, Jingqiang; Lin, Lu; Liu, Shijie; Ouyang, Pingkai

    2010-01-01

    Microcrystalline cellulose (MCC) was pretreated with phosphoric acid at 323K for 10h. X-ray diffraction (XRD) and Atomic Force Microscope (AFM) analyses revealed that the fiber surface morphology of pretreated MCC (P-MCC) were uneven and rough with the crystalline diffraction peaks of P-MCC decreased to a distinct range. The X-ray Photoelectron Spectroscopy (XPS) analysis showed that the uneven and rough surface of P-MCC could enhance the adsorption of cellulose to the molecular surface of cellulose, which is one of the key factors affecting enzymatic hydrolysis of cellulose. A reversible first order kinetics was employed to describe the adsorption kinetics of cellulase to MCC and P-MCC, and the adsorption rate constants of MCC and P-MCC were found to be 0.016, 0.024, 0.041, and 0.095, 0.149, 0.218min(-1), respectively at 278K, 293K and 308K. The activation energies of MCC and P-MCC hydrolysis reactions were found to be 22.257 and 19.721kJ mol(-1). The major hydrolysis products of MCC and P-MCC were cellobiose and glucose. Hydrolysis of MCC for 120h resulted in yields of glucose (7.21%), cellobiose (13.16%) and total sugars (20.37%). However, after the pretreatment with phosphoric acid, the corresponding sugar yields resulted from enzymatic hydrolysis of P-MCC were increased to 24.10%, 41.42%, and 65.52%; respectively, which were 3.34, 3.15, and 3.22 times of the sugars yields from enzymatic hydrolysis of MCC. Copyright 2010 Elsevier Inc. All rights reserved.

  4. Hydrolysis of Straw in Ionic Liquids with Acid as Catalyst under Microwave Irradiation

    Directory of Open Access Journals (Sweden)

    Yuanjing Zhang

    2015-01-01

    Full Text Available With ionic liquids as solvents and corn straw as raw material, different processes of lignocellulose pretreatment with acid as catalyst were studied under conventional heating/microwave irradiation and the reducing sugar was measured. The results indicated that acid can accelerate hydrolysis reaction of corn straw into reducing sugar with ionic liquids as solvent, and microwave irradiation was more efficient in pretreatment of corn straw than conventional heating. The influences of different acid catalysts, the concentration of acid, temperature, mass ratio of straw/[Bmim]Cl, and the amount of refill water were mainly tested, and the optimum experimental conditions are thus determined.

  5. Caffeic acid treatment alters the extracellular adenine nucleotide hydrolysis in platelets and lymphocytes of adult rats.

    Science.gov (United States)

    Anwar, Javed; Spanevello, Roselia Maria; Pimentel, Victor Camera; Gutierres, Jessié; Thomé, Gustavo; Cardoso, Andreia; Zanini, Daniela; Martins, Caroline; Palma, Heloisa Einloft; Bagatini, Margarete Dulce; Baldissarelli, Jucimara; Schmatz, Roberta; Leal, Cláudio Alberto Martins; da Costa, Pauline; Morsch, Vera Maria; Schetinger, Maria Rosa Chitolina

    2013-06-01

    This study evaluated the effects of caffeic acid on ectonucleotidase activities such as NTPDase (nucleoside triphosphate diphosphohydrolase), Ecto-NPP (nucleotide pyrophosphatase/phosphodiesterase), 5'-nucleotidase and adenosine deaminase (ADA) in platelets and lymphocytes of rats, as well as in the profile of platelet aggregation. Animals were divided into five groups: I (control); II (oil); III (caffeic acid 10 mg/kg); IV (caffeic acid 50 mg/kg); and V (caffeic acid 100 mg/kg). Animals were treated with caffeic acid diluted in oil for 30 days. In platelets, caffeic acid decreased the ATP hydrolysis and increased ADP hydrolysis in groups III, IV and V when compared to control (P<0.05). The 5'-nucleotidase activity was decreased, while E-NPP and ADA activities were increased in platelets of rats of groups III, IV and V (P<0.05). Caffeic acid reduced significantly the platelet aggregation in the animals of groups III, IV and V in relation to group I (P<0.05). In lymphocytes, the NTPDase and ADA activities were increased in all groups treated with caffeic acid when compared to control (P<0.05). These findings demonstrated that the enzymes were altered in tissues by caffeic acid and this compound decreased the platelet aggregation suggesting that caffeic acid should be considered a potentially therapeutic agent in disorders related to the purinergic system.

  6. Modelling and Statistical Optimization of Dilute Acid Hydrolysis of Corn Stover Using Response Surface Methodology

    Directory of Open Access Journals (Sweden)

    Andrew Nosakhare Amenaghawon

    2014-07-01

    Full Text Available Response surface methodology (RSM was employed for the analysis of the simultaneous effect of acid concentration, pretreatment time and temperature on the total reducing sugar concentration obtained during acid hydrolysis of corn stover. A three-variable, three-level Box-Behnken design (BBD was used to develop a statistical model for the optimization of the process variables. The optimal hydrolysis conditions that resulted in the maximum total reducing sugar concentration were acid concentration; 1.72 % (w/w, temperature; 169.260C and pretreatment time; 48.73 minutes. Under these conditions, the total reducing sugar concentration was obtained to be 23.41g/L. Validation of the model indicated no difference between predicted and observed values.

  7. The effect of acid hydrolysis pretreatment on crystallinity and solubility of kenaf cellulose membrane

    Science.gov (United States)

    Saidi, Anis Syuhada Mohd; Zakaria, Sarani; Chia, Chin Hua; Jaafar, Sharifah Nabihah Syed; Padzil, Farah Nadia Mohammad

    2015-09-01

    Cellulose was extracted from kenaf core pulp (KCP) by series of bleaching steps in the sequence (DEED) where D and E are referred as acid and alkali treatment. The bleached kenaf pulp (BKCP) is then pretreated with acid hydrolysis at room temperature for 1 and 3 h respectively. The pretreated cellulose is dissolved in lithium hydroxide/urea (LiOH/urea) and cellulose solution produced was immersed in distilled water bath. BKCP without treatment was also conducted for comparison purpose. The effects of acid hydrolysis pretreatment on solubility and crystallinity are investigated. Higher solubility of cellulose solution is achieved for treated samples. Cellulose II formation and crystallinity index of the cellulose membrane were determined by X-ray diffraction (XRD).

  8. The effect of acid hydrolysis pretreatment on crystallinity and solubility of kenaf cellulose membrane

    Energy Technology Data Exchange (ETDEWEB)

    Saidi, Anis Syuhada Mohd; Zakaria, Sarani; Chia, Chin Hua; Jaafar, Sharifah Nabihah Syed; Padzil, Farah Nadia Mohammad [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2015-09-25

    Cellulose was extracted from kenaf core pulp (KCP) by series of bleaching steps in the sequence (DEED) where D and E are referred as acid and alkali treatment. The bleached kenaf pulp (BKCP) is then pretreated with acid hydrolysis at room temperature for 1 and 3 h respectively. The pretreated cellulose is dissolved in lithium hydroxide/urea (LiOH/urea) and cellulose solution produced was immersed in distilled water bath. BKCP without treatment was also conducted for comparison purpose. The effects of acid hydrolysis pretreatment on solubility and crystallinity are investigated. Higher solubility of cellulose solution is achieved for treated samples. Cellulose II formation and crystallinity index of the cellulose membrane were determined by X-ray diffraction (XRD)

  9. Optimization of wastewater microalgae saccharification using dilute acid hydrolysis for acetone, butanol, and ethanol fermentation

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Yessica; Ellis, Joshua T.; Miller, Charles D.; Sims, Ronald C.

    2015-02-01

    Exploring and developing sustainable and efficient technologies for biofuel production are crucial for averting global consequences associated with fuel shortages and climate change. Optimization of sugar liberation from wastewater algae through acid hydrolysis was determined for subsequent fermentation to acetone, butanol, and ethanol (ABE) by Clostridium saccharoperbutylacetonicum N1-4. Acid concentration, retention time, and temperature were evaluated to determine optimal hydrolysis conditions by assessing the sugar and ABE yield as well as the associated costs. Sulfuric acid concentrations ranging from 0-1.5 M, retention times of 40-120 min, and temperatures from 23°C- 90°C were combined to form a full factorial experiment. Acid hydrolysis pretreatment of 10% dried wastewater microalgae using 1.0 M sulfuric acid for 120 min at 80-90°C was found to be the optimal parameters, with a sugar yield of 166.1 g for kg of dry algae, concentrations of 5.23 g/L of total ABE, and 3.74 g/L of butanol at a rate of USD $12.83 per kg of butanol.

  10. Subcritical Water Hydrolysis of Peptides: Amino Acid Side-Chain Modifications

    Science.gov (United States)

    Powell, Thomas; Bowra, Steve; Cooper, Helen J.

    2017-09-01

    Previously we have shown that subcritical water may be used as an alternative to enzymatic digestion in the proteolysis of proteins for bottom-up proteomics. Subcritical water hydrolysis of proteins was shown to result in protein sequence coverages greater than or equal to that obtained following digestion with trypsin; however, the percentage of peptide spectral matches for the samples treated with trypsin were consistently greater than for those treated with subcritical water. This observation suggests that in addition to cleavage of the peptide bond, subcritical water treatment results in other hydrolysis products, possibly due to modifications of amino acid side chains. Here, a model peptide comprising all common amino acid residues (VQSIKCADFLHYMENPTWGR) and two further model peptides (VCFQYMDRGDR and VQSIKADFLHYENPTWGR) were treated with subcritical water with the aim of probing any induced amino acid side-chain modifications. The hydrolysis products were analyzed by direct infusion electrospray tandem mass spectrometry, either collision-induced dissociation or electron transfer dissociation, and liquid chromatography collision-induced dissociation tandem mass spectrometry. The results show preferential oxidation of cysteine to sulfinic and sulfonic acid, and oxidation of methionine. In the absence of cysteine and methionine, oxidation of tryptophan was observed. In addition, water loss from aspartic acid and C-terminal amidation were observed in harsher subcritical water conditions. [Figure not available: see fulltext.

  11. Inhibition effects of dilute-acid prehydrolysate of corn stover on enzymatic hydrolysis of Solka Floc.

    Science.gov (United States)

    Kothari, Urvi D; Lee, Yoon Y

    2011-11-01

    Dilute-acid pretreatment liquor (PL) produced at NREL through a continuous screw-driven reactor was analyzed for sugars and other potential inhibitory components. Their inhibitory effects on enzymatic hydrolysis of Solka Floc were investigated. When the PL was mixed into the enzymatic hydrolysis reactor at 1:1 volume ratio, the glucan and xylan digestibility decreased by 63% and 90%, respectively. The tolerance level of the enzyme for each inhibitor was determined. Of the identified degradation components, acetic acid was found to be the strongest inhibitor for cellulase activity, as it decreased the glucan yield by 10% at 1 g/L. Among the sugars, cellobiose and glucose were found to be strong inhibitors to glucan hydrolysis, whereas xylose is a strong inhibitor to xylan hydrolysis. Xylo-oligomers inhibit xylan digestibility more strongly than the glucan digestibility. Inhibition by the PL was higher than that of the simulated mixture of the identifiable components. This indicates that some of the unidentified degradation components, originated mostly from lignin, are potent inhibitors to the cellulase enzyme. When the PL was added to a simultaneous saccharification and co-fermentation using Escherichia coli KO11, the bioprocess was severely inhibited showing no ethanol formation or cell growth.

  12. Effects of acid-hydrolysis and hydroxypropylation on functional properties of sago starch.

    Science.gov (United States)

    Fouladi, Elham; Mohammadi Nafchi, Abdorreza

    2014-07-01

    In this study, sago starch was hydrolyzed by 0.14M HCl for 6, 12, 18, and 24h, and then modified by propylene oxide at a concentration of 0-30% (v/w). The effects of hydrolysis and etherification on molecular weight distribution, physicochemical, rheological, and thermal properties of dually modified starch were estimated. Acid hydrolysis of starch decreased the molecular weight of starch especially amylopectin, but hydroxypropylation had no effect on the molecular weight distribution. The degree of Molar substitution (DS) of hydroxypropylated starch after acid hydrolysis ranged from 0.007 to 0.15. Dually modified starch with a DS higher than 0.1 was completely soluble in cold water at up to 25% concentration of the starch. This study shows that hydroxypropylation and hydrolysis have synergistic effects unlike individual modifications. Dually modified sago starch can be applied to dip-molding for food and pharmaceutical processing because of its high solubility and low tendency for retrogradation.

  13. Enhanced enzymatic hydrolysis of kenaf core using irradiation and dilute acid

    Science.gov (United States)

    Lee, Byoung-Min; Jeun, Joon-Pyo; Kang, Phil-Hyun

    2017-01-01

    This study was performed to determine the effect of electron beam dose and enzymatic hydrolysis time for production of sugar such as glucose and xylose. After kenaf core was exposed to an irradiation dose that ranged from 0 to 500 kGy, the irradiated kenaf core was treated with a 3% (v/v) sulfuric acid solution using an autoclave for 5 h at 120 °C. The pretreated kenaf core was subsequently subjected to enzymatic hydrolysis at 50 °C in a shaking water bath at 150 rpm for 12, 24, 48, and 72 h. The determined enzyme activity rates were 70 FPU (Celluclast 1.5 L) and 40 CBU (Novozyme-188). The crystallinity index decreased from 50.6% in a non-pretreated kenaf core to 27.7% in kenaf core that was subjected to the two-stage pretreatment at dose of 500 kGy. The sugar yield of the two-stage pretreated kenaf core increased with an increase in irradiation dose. The sugar yield after 72 h of enzymatic hydrolysis was 73.6% at its highest with an irradiation dose of 500 kGy. The enhancement of enzymatic hydrolysis by two-stage pretreatment was more effective than non- and single pretreatment (36.9%, 40.6% and 44.0% in non-pretreatment, electron beam and dilute acid, respectively).

  14. Determination of chitosan with a modified acid hydrolysis and HPLC method.

    Science.gov (United States)

    Li, Bo; Zhang, Jiali; Bu, Fen; Xia, Wenshui

    2013-01-25

    Acid hydrolysis and subsequent quantification of glucosamine (GlcN) are widely used for chitosan quantification. Degradation of GlcN during chitosan hydrolysis was the main reason for the decrease of recovery, which made the method improper for the quantification of chitosan. Ten milligram of chitosan hydrolyzed with 10 mL mixed acid solution of HCl-H₃PO₄ (75:25 in molar ratio) showed the highest recovery, significantly higher than HCl hydrolysis. Further study revealed that the optimum conditions involved the hydrolysis with HCl-H₃PO₄ (4.5:1.5M) for 24 h at 110 °C. The hydrolysate was neutralized and derived with 9-fluorenylmethoxycarbonyl chloride (FMOC-Cl) before HPLC quantification. The optimum ratio of FMOC-Cl:GlcN was 53:1, with excess FMOC-Cl induced by the high ionic strength of the solution. This quantification procedure was then validated and proved to be specific, with good linearity, accuracy, and precision, making it well-suited for the determination of chitosan.

  15. Surface chemical compositions and dispersity of starch nanocrystals formed by sulfuric and hydrochloric acid hydrolysis.

    Science.gov (United States)

    Wei, Benxi; Xu, Xueming; Jin, Zhengyu; Tian, Yaoqi

    2014-01-01

    Surface chemical compositions of starch nanocrystals (SNC) prepared using sulfuric acid (H2SO4) and hydrochloric acid (HCl) hydrolysis were analyzed by X-ray photoelectron spectroscopy (XPS) and FT-IR. The results showed that carboxyl groups and sulfate esters were presented in SNC after hydrolysis with H2SO4, while no sulfate esters were detected in SNC during HCl-hydrolysis. TEM results showed that, compared to H2SO4-hydrolyzed sample, a wider size distribution of SNC prepared by HCl-hydrolysis were observed. Zeta-potentials were -23.1 and -5.02 mV for H2SO4- and HCl-hydrolyzed SNC suspensions at pH 6.5, respectively. Nevertheless, the zeta-potential values decreased to -32.3 and -10.2 mV as the dispersion pH was adjusted to 10.6. After placed 48 h at pH 10.6, zeta-potential increased to -24.1 mV for H2SO4-hydrolyzed SNC, while no change was detected for HCl-hydrolyzed one. The higher zeta-potential and relative small particle distribution of SNC caused more stable suspensions compared to HCl-hydrolyzed sample.

  16. Surface chemical compositions and dispersity of starch nanocrystals formed by sulfuric and hydrochloric acid hydrolysis.

    Directory of Open Access Journals (Sweden)

    Benxi Wei

    Full Text Available Surface chemical compositions of starch nanocrystals (SNC prepared using sulfuric acid (H2SO4 and hydrochloric acid (HCl hydrolysis were analyzed by X-ray photoelectron spectroscopy (XPS and FT-IR. The results showed that carboxyl groups and sulfate esters were presented in SNC after hydrolysis with H2SO4, while no sulfate esters were detected in SNC during HCl-hydrolysis. TEM results showed that, compared to H2SO4-hydrolyzed sample, a wider size distribution of SNC prepared by HCl-hydrolysis were observed. Zeta-potentials were -23.1 and -5.02 mV for H2SO4- and HCl-hydrolyzed SNC suspensions at pH 6.5, respectively. Nevertheless, the zeta-potential values decreased to -32.3 and -10.2 mV as the dispersion pH was adjusted to 10.6. After placed 48 h at pH 10.6, zeta-potential increased to -24.1 mV for H2SO4-hydrolyzed SNC, while no change was detected for HCl-hydrolyzed one. The higher zeta-potential and relative small particle distribution of SNC caused more stable suspensions compared to HCl-hydrolyzed sample.

  17. Acid hydrolysis of crude tannins from infructescence of Platycarya strobilacea Sieb. et Zucc to produce ellagic acid.

    Science.gov (United States)

    Zhang, Liangliang; Wang, Yongmei; Xu, Man

    2014-01-01

    The infructescence of Platycarya strobilacea Sieb. et Zucc is a well-known traditional medicine in China, Japan and Korea. The infructescence of P. strobilacea Sieb. et Zucc is a rich source of ellagitannins that are composed of ellagic acid (EA) and gallic acid, linked to a sugar moiety. The aim of this study was to prepare EA by acid hydrolysis of crude tannins from the infructescence of P. strobilacea Sieb. et Zucc, and establish a new technological processing method for EA. The natural antioxidant EA was prepared by using the water extraction of infructescence of P. strobilacea Sieb. et Zucc, evaporation, condensation, acid hydrolysis and prepared by the process of crystallisation. The yield percentage of EA from crude EA was more than 20% and the purity of the product was more than 98%, as identified by using HPLC. The structure was identified on the basis of spectroscopic analysis and comparison with authentic compound.

  18. Effect of Biological and Chemical Pre-treatment on the Hydrolysis of Corn Leaf

    Directory of Open Access Journals (Sweden)

    Kenia Ángeles Ramírez

    2014-09-01

    Full Text Available Hydrolysis of corn leaf utilizing two treatment sequences was carried out in this study. The first treatment was chemical and involved subjecting the corn leaf to an alkaline pre-treatment and then to a smooth acid hydrolysis. The second consisted of biological delignification using the strain Trametes sp. 44 H88, followed by enzymatic hydrolysis using the enzymatic extract produced by Trichoderma sp. H88. The ligninolytic extract produced by Trametes sp. 44 H88 was used to detoxify the hydrolyzate. The results indicate that biological pre-treatment with delignification is more favorable and improves the subsequent hydrolysis, regardless of whether the hydrolysis is chemical or biological. The chemical treatment sequence obtained 80% conversion of monosaccharides, while the biological treatment sequence resulted in a 87% conversion rate. Finally, the use of the ligninolytic extract for the dephenolization of the hydrolyzate reduced the presence of compounds of phenolic origin by 23%.

  19. Nanocellulose prepared by acid hydrolysis of isolated cellulose from sugarcane bagasse

    Science.gov (United States)

    Wulandari, W. T.; Rochliadi, A.; Arcana, I. M.

    2016-02-01

    Cellulose in nanometer range or called by nano-cellulose has attracted much attention from researchers because of its unique properties. Nanocellulose can be obtained by acid hydrolysis of cellulose. The cellulose used in this study was isolated from sugarcane bagasse, and then it was hydrolyzed by 50% sulfuric acid at 40 °C for 10 minutes. Nanocellulose has been characterized by Transmission Electron Microscope (TEM), Particle Size Analyzer (PSA), Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD). Analysis of FTIR showed that there were not a new bond which formed during the hydrolysis process. Based on the TEM analysis, nano-cellulose has a spherical morphology with an average diameter of 111 nm and a maximum distribution of 95.9 nm determined by PSA. The XRD analysis showed that the crystallinity degree of nano-cellulose was higher than cellulose in the amount of 76.01%.

  20. Bio-conversion of apple pomace into ethanol and acetic acid: Enzymatic hydrolysis and fermentation.

    Science.gov (United States)

    Parmar, Indu; Rupasinghe, H P Vasantha

    2013-02-01

    Enzymatic hydrolysis of cellulose present in apple pomace was investigated using process variables such as enzyme activity of commercial cellulase, pectinase and β-glucosidase, temperature, pH, time, pre-treatments and end product separation. The interaction of enzyme activity, temperature, pH and time had a significant effect (Pfermented using Saccharomyces cerevisae yielding 19.0g ethanol/100g DM. Further bio-conversion using Acetobacter aceti resulted in the production of acetic acid at a concentration of 61.4g/100g DM. The present study demonstrates an improved process of enzymatic hydrolysis of apple pomace to yield sugars and concomitant bioconversion to produce ethanol and acetic acid.

  1. Trans-dichlorodiammineplatinum(II). Acid hydrolysis and the isotopic exchange of the chloride ligands

    Energy Technology Data Exchange (ETDEWEB)

    Martin, Jr., D. S.; Adams, R. J.

    1961-12-31

    The isotopic exchange of chloride ligands of trans-dichlorodiammineplatinum(II) was explored. The rates of isotopic exchange were measured with Cl/sup 36/tracer only in solutions which were at chemical equilibrium. The exchange rate was found to contain a second-order (chloride-dependent) term, in addition to the expected acid hydrolysis term. At Cl/sup -/= 0.l M, the two processes contribute about equally to the exchange. It was also found that k/sub 1/ for t-Pt(NH/sub 3/)sub 2/Cl/sub 2/is larger than for any of the other chloroamine complexes. A summary of the acid hydrolysis equilibrium quotients and rate constants for platinum (II) complexes and other data are tabulated. (P.C.H.)

  2. Quantification of dislocations in hemp fibers using acid hydrolysis and fiber segment length distributions

    DEFF Research Database (Denmark)

    Thygesen, Lisbeth Garbrecht

    2008-01-01

    Natural fibers such as flax or hemp may be used in composite materials. However, their use for this purpose is hampered by the large natural variation in tensile strength and other quality parameters. The first step in managing these variations is to develop methods for fast and reliable...... determination of relevant parameters. One quality parameter of the fibers is the amount of structural distortions known as dislocations or kink bands. Here, a method developed for the quantification of dislocations in pulp fibers was adapted and tested successfully for hemp yarn segments. The method is based...... on acid hydrolysis and subsequent determination of the fiber segment length distribution. The premise of the method is that acid hydrolysis causes fibers to break in the dislocations rather than in other places. By use of polarized light microscopy and image analysis it was found that the premise...

  3. Concentrated Sulfuric Acid Hydrolysis of Hardwood Aspen and Softwood Pine for Bioethanol Production

    OpenAIRE

    Janga, Kando Khalifa

    2011-01-01

    Bioethanol production from lignocellulosic biomass has been targeted as an alternative solution to the existing dependence on fossil fuels in the transportation sector. However, the recalcitrant nature of lignocelluloses has been a challenge to the hydrolytic processes and hence commercialization.This study has investigated the feasibility of the concentrated sulfuric acid hydrolysis (CSAH) process for bioethanol production from wood-based lignocelluloses. This is because the process enjoys h...

  4. DETECTION OF BACTERIAL TOXINS WITH MONOSACCHARIDE ARRAYS

    Science.gov (United States)

    Ngundi, Miriam M.; Taitt, Chris R.; McMurry, Scott A.; Kahne, Daniel; Ligler, Frances S.

    2006-01-01

    A large number of bacterial toxins, viruses and bacteria target carbohydrate derivatives on the cell surface to attach to and gain entry into the cell. We report here the use of a monosaccharide-based array to detect protein toxins. The array-based technique provides the capability to perform simultaneous multianalyte analyses. Arrays of N-acetyl galactosamine (GalNAc) and N-acetylneuraminic acid (Neu5Ac) derivatives were immobilized on the surface of a planar waveguide and were used as receptors for protein toxins. These arrays were probed with fluorescently labeled bacterial cells and protein toxins. While Salmonella typhimurium, Listeria monocytogenes, Escherichia coli and staphylococcal enterotoxin B (SEB) did not bind to either of the monosaccharides, both cholera toxin and tetanus toxin bound to GalNAc and Neu5Ac. The results show that the binding of the toxins to the carbohydrates is density dependent and semi-selective. Both toxins were detectable at 100 ng/ml. PMID:15946840

  5. Enzymatic hydrolysis of structurally diverse phthalic acid esters by porcine and bovine pancreatic cholesterol esterases.

    Science.gov (United States)

    Saito, Takao; Hong, Peng; Tanabe, Rima; Nagai, Kazuo; Kato, Katsuya

    2010-12-01

    A weak hydrolyzing activity against bis (2-ethylhexyl) phthalate (DEHP) was discovered in a commercial crude lipase (EC 3.1.1.3) preparation from porcine pancreas. DEHP was hydrolyzed to mono (2-ethylhexyl) phthalate (MEHP) not by a pancreatic lipase but by a cholesterol esterase (CEase, EC 3.1.1.13), a trace contaminant in the crude lipase preparation. Enzymatic hydrolysis of phthalic acid esters (PAEs), suspected to be endocrine-disrupting chemicals, was investigated using CEases from two species of mammals and a microorganism. Eight structurally diverse PAEs, namely diethyl phthalate (DEP), di-n-propyl phthalate (DPrP), di-n-butyl phthalate (DBP), di-n-pentyl phthalate (DPeP), di-n-hexyl phthalate (DHP), DEHP, n-butyl benzyl phthalate (BBP), and dicyclohexyl phthalate (DCHP), were hydrolyzed to their corresponding monoesters by both porcine and bovine pancreatic CEases, while a microbial CEase from Pseudomonas sp. had no hydrolyzing activity against these PAEs. The hydrolysis experiments with bovine pancreatic CEase (50 U) indicated complete hydrolysis of every PAE (5 μmole) except for BBP and DCHP within 15 min; BBP and DCHP were hydrolyzed within 30 min and 6h, respectively. The rates of PAE hydrolysis could be affected by the bulkiness of alkyl side chains in the PAEs. This study provides important evidence that mammalian pancreatic CEases, such as those from porcine and bovine sources, are potential enzymes for nonspecific degradation of structurally diverse PAEs.

  6. Preparation of crystalline starch nanoparticles using cold acid hydrolysis and ultrasonication.

    Science.gov (United States)

    Kim, Hee-Young; Park, Dong June; Kim, Jong-Yea; Lim, Seung-Taik

    2013-10-15

    Waxy maize starch in an aqueous sulfuric acid solution (3.16 M, 14.7% solids) was hydrolyzed for 2-6 days, either isothermally at 40 °C or 4 °C, or at cycled temperatures of 4 and 40 °C (1 day each). The starch hydrolyzates were recovered as precipitates after centrifuging the dispersion (10,000 rpm, 10 min). The yield of starch hydrolyzates depended on the hydrolysis temperature and time, which varied from 6.8% to 78%. The starch hydrolyzed at 40 °C or 4/40 °C exhibited increased crystallinity determined by X-ray diffraction analysis, but melted in broader temperature range (from 60 °C to 110 °C). However, the starch hydrolyzed at 4 °C displayed the crystallinity and melting endotherm similar to those of native starch. The starch hydrolyzates recovered by centrifugation were re-dispersed in water (15% solids), and the dispersion was treated by an ultrasonic treatment (60% amplitude, 3min). The ultrasonication effectively fragmented the starch hydrolyzates to nanoparticles. The hydrolyzates obtained after 6 days of hydrolysis were more resistant to the ultrasonication than those after 2 or 4 days, regardless of hydrolysis temperatures. The starch nanoparticles could be prepared with high yield (78%) and crystallinity by 4 °C hydrolysis for 6 days followed by ultrasonication. Scanning electron microscopy revealed that the starch nanoparticles had globular shapes with diameters ranging from 50 to 90 nm.

  7. The luminescence profile of carbon dots synthesized from α-cellulose under different acid hydrolysis conditions

    Science.gov (United States)

    Ng, Yann Huey; Chin, Suk Fun; Pang, Suh Cem; Ng, Sing Muk

    2017-08-01

    This work reports the study on the luminescence properties portrayed by carbon dots synthesized under different acid hydrolysis conditions. Sulphuric acid was employed to dehydrate and carbonize α-cellulose as starting precursor. We revealed that the emissions of carbon dots were strongly dependent on the reaction condition during the synthesis, which include hydrolysis time and temperature. Initial mild acid hydrolysis at 4 °C and followed by incubation at room temperature was found favourable to the production of carbon dots emitting green fluorescence, whereas higher temperatures of 50 and 70 °C would produce carbon dots emitting blue fluorescence. At fixed temperature of 50 °C, prolonged synthesis time could shift the emission of carbon dots from green to blue. The green emission was recorded to have a peak at 500 nm when excited at 450 nm; whereas the highest intensity for the blue emission was recorded at 456 nm when excited at 357 nm. Both as-synthesized carbon dots showed excitation-independent emission. The quantum yields for the green and blue carbon dots were evaluated to be 6.4% and 4.0% respectively. The carbon dots emitting blue emission was of better photostability as compared to the carbon dots emitting green fluorescence. Both types of carbon dots synthesized in this study showed significant pH-dependent trend with higher intensity at lower pH condition.

  8. Analysis of the monosaccharide composition of fucoidan by precolumn derivation HPLC

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jingjing; ZHANG Quanbin; WANG Jing; SHI Xuelian; ZHANG Zhongshan

    2009-01-01

    We developed an HPLC method for analysis of the monosaccharide composition of fucoidans. The fucoidan was hydrolyzed into monosaccharides with 2 mol/L trifluoroacetic acid. Using ribose as the internal standard, the monosaccharide derivatives, obtained with 1-Phenyl-3-methyl-5- pyrazolone (PMP), were separated by reverse-phase HPLC using a gradient elution process, and monitored by ultraviolet detection at 245 nm. In the concentration range of 0.1-2.0 mmol/L, the peak area of each monosaccharide had a good linear relationship with its concentration (r2>0.998). The average recoveries of mannose, rhamnose, glucuronic acid, glucose, galactose, xylose, and fucose were 86.2%, 95.1%, 62.5%, 102.0%, 94.8%, 66.6%, and 105.1%, respectively. This method was accurate and had good reproducibility and could be used to determine the monosaccharide contents of fucoidans.

  9. Analysis of the monosaccharide composition of fucoidan by precolumn derivation HPLC

    Science.gov (United States)

    Zhang, Jingjing; Zhang, Quanbin; Wang, Jing; Shi, Xuelian; Zhang, Zhongshan

    2009-09-01

    We developed an HPLC method for analysis of the monosaccharide composition of fucoidans. The fucoidan was hydrolyzed into monosaccharides with 2 mol/L trifluoroacetic acid. Using ribose as the internal standard, the monosaccharide derivatives, obtained with 1-Phenyl-3-methyl-5-pyrazolone (PMP), were separated by reverse-phase HPLC using a gradient elution process, and monitored by ultraviolet detection at 245 nm. In the concentration range of 0.1-2.0 mmol/L, the peak area of each monosaccharide had a good linear relationship with its concentration ( r 2>0.998). The average recoveries of mannose, rhamnose, glucuronic acid, glucose, galactose, xylose, and fucose were 86.2%, 95.1%, 62.5%, 102.0%, 94.8%, 66.6%, and 105.1%, respectively. This method was accurate and had good reproducibility and could be used to determine the monosaccharide contents of fucoidans.

  10. Effects of tempering (annealing), acid hydrolysis, low-citric acid substitution on chemical and physicochemical properties of starches of four yam (Dioscorea spp.) cultivars.

    Science.gov (United States)

    Falade, Kolawole O; Ayetigbo, Oluwatoyin E

    2017-05-01

    The effects of tempering (annealing), acid hydrolysis and low-citric acid substitution on chemical and physicochemical properties of starches of four Nigerian yam cultivars were investigated. Crude fat and protein contents of the native starches decreased significantly after the modifications, while nitrogen-free extract increased significantly with acid hydrolysis and citric acid substitution. Acid hydrolysis and low-citric acid substitution reduced the least concentration for gel formation of the starches from 4 to 2% w/v, but tempering had no effect. Swelling power of the starches reduced significantly, and water solubility increased significantly at 75 and 85 °C, especially with acid hydrolysis and low-citric acid substitution. However, tempering significantly reduced starch solubility in the four cultivars. Paste clarity of starches of white (29.17%), water (18.90%), yellow (30.90%) and bitter (10.57%) yams reduced significantly with tempering to 14.43, 11.83, 16.93 and 7.27%, but increased significantly with acid hydrolysis to 41.40, 35.37, 28.77 and 32.33%, and low-citric acid substitution to 36.60, 44.17, 50.67 and 14.33%, respectively. Pasting properties such as peak, trough, breakdown, final, and setback viscosities and peak time of native starches reduced significantly with acid hydrolysis and low-citric acid substitution, however, tempering significantly increased their pasting temperature, peak time, setback and final viscosities.

  11. Morphological characteristics, oxidative stability and enzymic hydrolysis of amylose-fatty acid complexes.

    Science.gov (United States)

    Marinopoulou, Anna; Papastergiadis, Efthimios; Raphaelides, Stylianos N; Kontominas, Michael G

    2016-05-05

    Complexes of amylose with fatty acids varying in carbon chain length and degree of unsaturation were prepared at 30, 50 or 70°C by dissolving amylose in 0.1N KOH and mixing with fatty acid potassium soap solution. The complexes were obtained in solid form as precipitates after neutralization. SEM microscopy revealed that the morphology of the complexes was that of ordered lamellae separated from amorphous regions whereas confocal laser scanning microscopy showed images of the topography of the guest molecules in the complex matrix. FTIR spectroscopy revealed that the absorption peak attributed to carbonyl group of free fatty acid was shifted when the fatty acid was in the form of amylose complex. Thermo-gravimetry showed that the unsaturated fatty acids were effectively protected from oxidation when they were complexed with amylose whereas enzymic hydrolysis experiments showed that the guest molecules were quantitatively released from the amylose complexes.

  12. Stagewise dilute-acid pretreatment and enzyme hydrolysis of distillers' grains and corn fiber.

    Science.gov (United States)

    Noureddini, Hossein; Byun, Jongwon; Yu, Ta-Jen

    2009-11-01

    Distillers' grains and corn fiber are the coproducts of the corn dry grind and wet milling industries, respectively. Availability of distillers' grains and corn fiber at the ethanol plant and their high levels of lignocellulosic material make these coproducts attractive feedstocks for conversion to ethanol. In this study, dilute sulfuric acid hydrolysis of these coproducts was investigated in a multistage scheme. After the completion of each pretreatment stage, the liquid substrate was separated and reused in the succeeding pretreatment stage with a fresh substrate. The substrate from each stage was also subjected to enzyme hydrolysis in a separate experiment. The sulfuric acid concentration and the substrate loading were maintained at 1.0 vol% and 15.0 wt.%, respectively, and the temperature was maintained at 120 degrees C in all the experiments. Experiments were also performed to study the effect of removing oil from the samples prior to the pretreatment. The highest concentration of monomeric sugars (MS) was observed when three stages of pretreatment were followed by the enzyme reaction. The enzyme hydrolysis of the three-stage pretreated dried distillers' grains and corn fiber yielded 122.6 +/- 5.8 and 184.5 +/- 4.1 mg/mL of MS, respectively. The formation of inhibitory products was also monitored.

  13. Mechanism of Orlistat Hydrolysis by the Thioesterase of Human Fatty Acid Synthase.

    Science.gov (United States)

    Fako, Valerie E; Zhang, Jian-Ting; Liu, Jing-Yuan

    2014-10-03

    Fatty acid synthase (FASN), the sole protein capable of de novo synthesis of free fatty acids, is overexpressed in a wide variety of human cancers and is associated with poor prognosis and aggressiveness of these cancers. Orlistat, an FDA-approved drug for obesity treatment that inhibits pancreatic lipases in the GI tract, also inhibits the thioesterase (TE) of human FASN. The cocrystal structure of TE with orlistat shows a pseudo TE dimer containing two different forms of orlistat in the active site, an intermediate that is covalently bound to a serine residue (Ser(2308)) and a hydrolyzed and inactivated product. In this study, we attempted to understand the mechanism of TE-catalyzed orlistat hydrolysis by examining the role of the hexyl tail of the covalently bound orlistat in water activation for hydrolysis using molecular dynamics simulations. We found that the hexyl tail of the covalently bound orlistat undergoes a conformational transition, which is accompanied by destabilization of a hydrogen bond between a hydroxyl moiety of orlistat and the catalytic His(2481) of TE that in turn leads to an increased hydrogen bonding between water molecules and His(2481) and increased chance for water activation to hydrolyze the covalent bond between orlistat and Ser(2308). Thus, the conformation of the hexyl tail of orlistat plays an important role in orlistat hydrolysis. Strategies that stabilize the hexyl tail may lead to the design of more potent irreversible inhibitors that target FASN and block TE activity with greater endurance.

  14. Improved enzymatic hydrolysis of wheat straw by combined use of gamma ray and dilute acid for bioethanol production

    Science.gov (United States)

    Hyun Hong, Sung; Taek Lee, Jae; Lee, Sungbeom; Gon Wi, Seung; Ju Cho, Eun; Singh, Sudhir; Sik Lee, Seung; Yeoup Chung, Byung

    2014-01-01

    Pretreating wheat straw with a combination of dilute acid and gamma irradiation was performed in an attempt to enhance the enzymatic hydrolysis for bioethanol production. The glucose yield was significantly affected by combined pretreatment (3% sulfuric acid-gamma irradiation), compared with untreated wheat straw and individual pretreatment. The increasing enzymatic hydrolysis after combined pretreatment is resulting from decrease in crystallinity of cellulose, loss of hemicelluloses, and removal or modification of lignin. Therefore, combined pretreatment is one of the most effective methods for enhancing the enzymatic hydrolysis of wheat straw biomass.

  15. Determination of Amino Acids in Panax notoginseng by Microwave Hydrolysis and Derivatization Coupled with Capillary Zone Electrophoresis Detection

    Institute of Scientific and Technical Information of China (English)

    LI Xiao-tian; ZHAO Ya-jing; JIANG Cheng-fei; ZHANG Han-qi; YU Ai-min

    2013-01-01

    The microwave hydrolysis and derivatization coupled with capillary electrophoresis detection were developed for the separation and determination of the amino acids in Panax notoginseng.The experimental conditions for the microwave hydrolysis and derivatization were examined and optimized.Several parameters of capillary electrophoresis,such as pH value of background electrolyte,borate concentration and applied voltage were optimized.Under the selected conditions,11 amino acids were completely separated.The real sample was analyzed and the results were satisfactory.Compared with that of conventional heat hydrolysis and derivatization,the analytical time of this method was significantly shortened.

  16. Sulfuric Acid Pretreatment and Enzymatic Hydrolysis of Photoperiod Sensitvie Sorghum for Ethanol Production

    Energy Technology Data Exchange (ETDEWEB)

    F Xu; Y Shi; X Wu

    2011-12-31

    Photoperiod sensitive (PS) sorghum, with high soluble sugar content, high mass yield and high drought tolerance in dryland environments, has great potential for bioethanol production. The effect of diluted sulfuric acid pretreatment on enzymatic hydrolysis was investigated. Hydrolysis efficiency increased from 78.9 to 94.4% as the acid concentration increased from 0.5 to 1.5%. However, the highest total glucose yield (80.3%) occurred at the 1.0% acid condition because of the significant cellulose degradation at the 1.5% concentration. Synchrotron wide-angle X-ray diffraction was used to study changes of the degree of crystallinity. With comparison of cellulosic crystallinity and adjusted cellulosic crystallinity, the crystalline cellulose decreased after low acidic concentration (0.5%) applied, but did not change significantly, as the acid concentration increased. Scanning electron microscopy was also employed to understand how the morphological structure of PS sorghum changed after pretreatment. Under current processing conditions, the total ethanol yield is 74.5% (about 0.2 g ethanol from 1 g PS sorghum). A detail mass balance was also provided.

  17. Value of Coproduction of Ethanol and Furfural from Acid Hydrolysis Processes

    Energy Technology Data Exchange (ETDEWEB)

    Parker, S.; Calnon, M.; Feinberg, D.; Power, A.; Weiss, L.

    1984-05-01

    In the acid hydrolysis of a cellulosic feedstock (wood, wood wastes, or crop residues), up to 3.65 lb of furfural may be coproduced with each gallon of ethanol for only the cost of recovering and purifying it. Each plant producing 50 x 106 gal/yr of ethanol would produce an amount of by-product furfural equal to the total current domestic production. Thus, the need arises for investigation into potentially suitable processes for deriving profitable end products from furfural and thus expanding the market. The objectives of this study were to determine the economic potential of five selected, large volume derivatives of furfural that could displace hydrocarbon-based chemicals, and the consequent value of furfural as a by-product to the cellulose hydrolysis process of ethanol production.

  18. Plantain starch granules morphology, crystallinity, structure transition, and size evolution upon acid hydrolysis.

    Science.gov (United States)

    Hernández-Jaimes, C; Bello-Pérez, L A; Vernon-Carter, E J; Alvarez-Ramirez, J

    2013-06-05

    Plantain native starch was hydrolysed with sulphuric acid for twenty days. Hydrolysis kinetics was described by a logistic function, with a zero-order rate during the first seven days, followed by a slower kinetics dynamics at longer times. X-ray diffraction results revealed a that gradual increase in crystallinity occurred during the first seven days, followed by a decrease to values similar to those found in the native starch. Differential scanning calorimetry analysis suggested a sharp structure transition by the seventh day probably due to a molecular rearrangement of the starch blocklets and inhomogeneous erosion of the amorphous regions and semi crystalline lamellae. Scanning electron micrographs showed that starch granules morphology was continually degraded from an initial oval-like shape to irregular shapes due to aggregation effects. Granule size distribution broadened as hydrolysis time proceeded probably due to fragmentation and agglomeration phenomena of the hydrolysed starch granules.

  19. Phosphoric acid pretreatment of Achyranthes aspera and Sida acuta weed biomass to improve enzymatic hydrolysis.

    Science.gov (United States)

    Siripong, Premjet; Duangporn, Premjet; Takata, Eri; Tsutsumi, Yuji

    2016-03-01

    Achyranthes aspera and Sida acuta, two types of weed biomass are abundant and waste in Thailand. We focus on them as novel feedstock for bio-ethanol production because they contain high-cellulose content (45.9% and 46.9%, respectively) and unutilized material. Phosphoric acid (70%, 75%, and 80%) was employed for the pretreatment to improve by enzymatic hydrolysis. The pretreatment process removed most of the xylan and a part of the lignin from the weeds, while most of the glucan remained. The cellulose conversion to glucose was greater for pretreated A. aspera (86.2 ± 0.3%) than that of the pretreated S. acuta (82.2 ± 1.1%). Thus, the removal of hemicellulose significantly affected the efficiency of the enzymatic hydrolysis. The scanning electron microscopy images showed the exposed fibrous cellulose on the cell wall surface, and this substantial change of the surface structure contributed to improving the enzyme accessibility.

  20. Kinetic study of enzymatic hydrolysis of acid-pretreated coconut coir

    Science.gov (United States)

    Fatmawati, Akbarningrum; Agustriyanto, Rudy

    2015-12-01

    Biomass waste utilization for biofuel production such as bioethanol, has become more prominent currently. Coconut coir is one of lignocellulosic food wastes, which is abundant in Indonesia. Bioethanol production from such materials consists of more than one step. Pretreatment and enzymatic hydrolysis is crucial steps to produce sugar which can then be fermented into bioethanol. In this research, ground coconut coir was pretreated using dilute sulfuric acid at 121°C. This pretreatment had increased the cellulose content and decreased the lignin content of coconut coir. The pretreated coconut coir was hydrolyzed using a mix of two commercial cellulase enzymes at pH of 4.8 and temperature of 50°C. The enzymatic hydrolysis was conducted at several initial coconut coir slurry concentrations (0.1-2 g/100 mL) and reaction times (2-72 hours). The reducing sugar concentration profiles had been produced and can be used to obtain reaction rates. The highest reducing sugar concentration obtained was 1,152.567 mg/L, which was produced at initial slurry concentration of 2 g/100 mL and 72 hours reaction time. In this paper, the reducing sugar concentrations were empirically modeled as a function of reaction time using power equations. Michaelis-Menten kinetic model for enzymatic hydrolysis reaction is adopted. The kinetic parameters of that model for sulfuric acid-pretreated coconut coir enzymatic hydrolysis had been obtained which are Vm of 3.587×104 mg/L.h, and KM of 130.6 mg/L.

  1. Kinetics and mechanism of acid-catalyzed hydrolysis of the diazo functional groups of 1-diazo-2-indanone and 2-diazo-1-indanone in aqueous solution

    National Research Council Canada - National Science Library

    Chiang, Yvonne; Kresge, A J; Sadovski, Oleg; Zeng, Xiaofeng; Zhu, Yu

    2005-01-01

    Rates of hydrolysis of 1-diazo-2-indanone and 2-diazo-1-indanone were measured in dilute aqueous perchloric acid solutions using both H2O and D2O as the solvent, and rates of hydrolysis of the latter...

  2. Comparative study on two-step concentrated acid hydrolysis for the extraction of sugars from lignocellulosic biomass.

    Science.gov (United States)

    Wijaya, Yanuar Philip; Putra, Robertus Dhimas Dhewangga; Widyaya, Vania Tanda; Ha, Jeong-Myeong; Suh, Dong Jin; Kim, Chang Soo

    2014-07-01

    Among all the feasible thermochemical conversion processes, concentrated acid hydrolysis has been applied to break the crystalline structure of cellulose efficiently and scale up for mass production as lignocellulosic biomass fractionation process. Process conditions are optimized by investigating the effect of decrystallization sulfuric acid concentration (65-80 wt%), hydrolysis temperature (80°C and 100°C), hydrolysis reaction time (during two hours), and biomass species (oak wood, pine wood, and empty fruit bunch (EFB) of palm oil) toward sugar recovery. At the optimum process condition, 78-96% sugars out of theoretically extractable sugars have been fractionated by concentrated sulfuric acid hydrolysis of the three different biomass species with 87-90 g/L sugar concentration in the hydrolyzate and highest recalcitrance of pine (softwood) was determined by the correlation of crystallinity index and sugar yield considering reaction severity.

  3. A novel diffusion-biphasic hydrolysis coupled kinetic model for dilute sulfuric acid pretreatment of corn stover.

    Science.gov (United States)

    Chen, Longjian; Zhang, Haiyan; Li, Junbao; Lu, Minsheng; Guo, Xiaomiao; Han, Lujia

    2015-02-01

    Kinetic experiments on the dilute sulfuric acid pretreatment of corn stover were performed. A high xylan removal and a low inhibitor concentration were achieved by acid pretreatment. A novel diffusion-hydrolysis coupled kinetic model was proposed. The contribution to the xylose yield was analyzed by the kinetic model. Compared with the inhibitor furfural negatively affecting xylose yield, the fast and slow-hydrolyzing xylan significantly contributed to the xylose yield, however, their dominant roles were dependent on reaction temperature and time. The impact of particle size and acid concentration on the xylose yield were also investigated. The diffusion process may significantly influence the hydrolysis of large particles. Increasing the acid concentration from 0.15 M to 0.30 M significantly improved the xylose yield, whereas the extent of improvement decreased to near-quantitative when further increasing acid loading. These findings shed some light on the mechanism for dilute sulfuric acid hydrolysis of corn stover.

  4. Application of acid-catalyzed hydrolysis of dispersed organic solvent in developing new microencapsulation process technology.

    Science.gov (United States)

    Lee, Honghwa; Lee, Sunhwa; Bhattacharjee, Himanshu; Sah, Hongkee

    2012-01-01

    The aim of this study was to evaluate a new microencapsulation technology employing an acid-catalyzed solvent extraction method in conjunction to an emulsion-based microencapsulation process. Its process consisted of emulsifying a dispersed phase of poly(D,L-lactide-co-glycolide) and isopropyl formate in an aqueous phase. This step was followed by adding hydrochloric acid to the resulting oil-in-water emulsion, in order to initiate the hydrolysis of isopropyl formate dissolved in the aqueous phase. Its hydrolysis caused the liberation of water-soluble species, that is, isopropanol and formic acid. This event triggered continual solvent leaching out of emulsion droplets, thereby initiating microsphere solidification. This new processing worked well for encapsulation of progesterone and ketoprofen that were chosen as a nonionizable model drug and a weakly acidic one, respectively. Furthermore, the structural integrity of poly(D,L-lactide-co-glycolide) was retained during microencapsulation. The new microencapsulation technology, being conceptually different from previous approaches, might be useful in preparing various polymeric particles.

  5. Acid-based hydrolysis processes for ethanol from lignocellulosic materials: A review

    Directory of Open Access Journals (Sweden)

    Keikhosro Karimi

    2007-01-01

    Full Text Available Bioethanol is nowadays one of the main actors in the fuel market. It is currently produced from sugars and starchy materials, but lignocelluloses can be expected to be major feedstocks for ethanol production in the future. Two processes are being developed in parallel for conversion of lignocelluloses to ethanol, “acid-based” and “enzyme-based” processes. The current article is dedicated to review of progress in the “acid-based-hydrolysis” process. This process was used industrially in the 1940s, during wartime, but was not economically competitive afterward. However, intensive research and development on its technology during the last three decades, in addition to the expanding ethanol market, may revive the process in large scale once again. In this paper the ethanol market, the composition of lignocellulosic materials, concentrated- and dilute-acid pretreatment and hydrolysis, plug-flow, percolation, counter-current and shrinking-bed hydrolysis reactors, fermentation of hexoses and pentoses, effects of fermentation inhibitors, downstream processing, wastewater treatment, analytical methods used, and the current commercial status of the acid-based ethanol processes are reviewed.

  6. Effect of ultrasonic pre-treatment on low temperature acid hydrolysis of oil palm empty fruit bunch.

    Science.gov (United States)

    Yunus, Robiah; Salleh, Shanti Faridah; Abdullah, Nurhafizah; Biak, Dyg Radiah Awg

    2010-12-01

    Various pre-treatment techniques change the physical and chemical structure of the lignocellulosic biomass and improve hydrolysis rates. The effect of ultrasonic pre-treatment on oil palm empty fruit bunch (OPEFB) fibre prior to acid hydrolysis has been evaluated. The main objective of this study was to determine if ultrasonic pre-treatment could function as a pre-treatment method for the acid hydrolysis of OPEFB fibre at a low temperature and pressure. Hydrolysis at a low temperature was studied using 2% sulphuric acid; 1:25 solid liquid ratio and 100 degrees C operating temperature. A maximum xylose yield of 58% was achieved when the OPEFB fibre was ultrasonicated at 90% amplitude for 45min. In the absence of ultrasonic pre-treatment only 22% of xylose was obtained. However, no substantial increase of xylose formation was observed for acid hydrolysis at higher temperatures of 120 and 140 degrees C on ultrasonicated OPEFB fibre. The samples were then analysed using a scanning electron microscope (SEM) to describe the morphological changes of the OPEFB fibre. The SEM observations show interesting morphological changes within the OPEFB fibre for different acid hydrolysis conditions.

  7. Hydrolysis of p-Nitrophenyl Picolinate Catalyzed by Mono-and Binuclear Transition Metal Complexes with Polyether Bridged Dihydroxamic Acid

    Institute of Scientific and Technical Information of China (English)

    李建章; 李鸿波; 冯发美; 谢家庆; 李慎新; 周波; 秦圣英

    2005-01-01

    Two polyether bridged dihydroxamic acids and their mono-and binuclear manganese(Ⅱ), zinc(Ⅱ) complexes have been synthesized and employed as models to mimic hydrolase in catalytic hydrolysis of p-nitrophenyl picolinate (PNPP). The reaction kinetics and the mechanism of hydrolysis of PNPP have been investigated. The kinetic mathematical model for PNPP cleaved by the complexes has been proposed. The effects of the different central metal ion, mono-and binuclear metal, the pseudo-macrocyclic polyether constructed by polyethoxy group of the complexes, and reactive temperature on the rate for catalytic hydrolysis of PNPP have been examined. The results showed that the transition metal dthydroxamates exhibited high catalytic activity to the hydrolysis of PNPP, the catalytic activity of binuclear complexes was higher than that of mononuclear ones, and the pseudo-macrocyclic polyether might synergetically activate H20 coordinated to metal ion with central metal ion together and promote the catalytic hydrolysis of PNPP.

  8. CHEMICAL CHARACTERISATION AND DILUTE-ACID HYDROLYSIS OF RICE HULLS FROM AN ARTISAN MILL

    Directory of Open Access Journals (Sweden)

    Yoney López

    2010-09-01

    Full Text Available The chemical composition of rice hulls produced in an artisan mill and its conversion to fermentable sugars was investigated. The carbohydrate fraction represented 59.2% (w/w of the dry hulls. Cellulose, with 36.6%, was the main component, followed by xylan with 13.9%. An important contribution of starch (8.7% was also detected. The content of ash (19.6% and lignin (15.5% was comparable with that of rice hulls obtained in industrial mills. Dilute-sulphuric acid hydrolysis at different temperatures, from 160 to 210°C, was evaluated for production of fermentable sugars. Due to starch hydrolysis, the concentration of glucose in the hydrolysates produced at 160°C was higher than the values that have previously been reported for industrial sorts of rice hulls under comparable conditions. The xylan-to-xylose conversion increased steadily with increase of the temperature and reached a maximum (67.7% at 190°C. Further increases of the hydrolysis temperature decreased the yield of sugars due to their dehydration to furfural and HMF.

  9. Effect of citric acid concentration and hydrolysis time on physicochemical properties of sweet potato starches.

    Science.gov (United States)

    Surendra Babu, Ayenampudi; Parimalavalli, Ramanathan; Rudra, Shalini Gaur

    2015-09-01

    Physicochemical properties of citric acid treated sweet potato starches were investigated in the present study. Sweet potato starch was hydrolyzed using citric acid with different concentrations (1 and 5%) and time periods (1 and 11 h) at 45 °C and was denoted as citric acid treated starch (CTS1 to CTS4) based on their experimental conditions. The recovery yield of acid treated starches was above 85%. The CTS4 sample displayed the highest amylose (around 31%) and water holding capacity its melting temperature was 47.66 °C. The digestibility rate was slightly increased for 78.58% for the CTS3 and CTS4. The gel strength of acid modified starches ranged from 0.27 kg to 1.11 kg. RVA results of acid thinned starches confirmed a low viscosity profile. CTS3 starch illustrated lower enthalpy compared to all other modified starches. All starch samples exhibited a shear-thinning behavior. SEM analysis revealed that the extent of visible degradation was increased at higher hydrolysis time and acid concentration. The CTS3 satisfied the criteria required for starch to act as a fat mimetic. Overall results conveyed that the citric acid treatment of sweet potato starch with 5% acid concentration and 11h period was an ideal condition for the preparation of a fat replacer.

  10. Microwave-assisted acid and base hydrolysis of intact proteins containing disulfide bonds for protein sequence analysis by mass spectrometry.

    Science.gov (United States)

    Reiz, Bela; Li, Liang

    2010-09-01

    Controlled hydrolysis of proteins to generate peptide ladders combined with mass spectrometric analysis of the resultant peptides can be used for protein sequencing. In this paper, two methods of improving the microwave-assisted protein hydrolysis process are described to enable rapid sequencing of proteins containing disulfide bonds and increase sequence coverage, respectively. It was demonstrated that proteins containing disulfide bonds could be sequenced by MS analysis by first performing hydrolysis for less than 2 min, followed by 1 h of reduction to release the peptides originally linked by disulfide bonds. It was shown that a strong base could be used as a catalyst for microwave-assisted protein hydrolysis, producing complementary sequence information to that generated by microwave-assisted acid hydrolysis. However, using either acid or base hydrolysis, amide bond breakages in small regions of the polypeptide chains of the model proteins (e.g., cytochrome c and lysozyme) were not detected. Dynamic light scattering measurement of the proteins solubilized in an acid or base indicated that protein-protein interaction or aggregation was not the cause of the failure to hydrolyze certain amide bonds. It was speculated that there were some unknown local structures that might play a role in preventing an acid or base from reacting with the peptide bonds therein.

  11. Catalytic hydrolysis of CFC-12 over solid acid Ti(SO4)2

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The catalytic hydrolysis of dichlorodifluoromethane (CFC-12) was investigated over solid acid Ti(SO4)2. The catalytic activity decreased with the calcination temperature. When space velocity was 6 l h-1 g-cat-1, the CFC-12 conversion at 310oC over Ti(SO4)2 calcined at 350oC remained about 98.5% during 360 h on stream, and the selectivity to by-products remained zero. The findings enlarged the scope of traditional catalyst systems for the CFCs decomposition.

  12. Hydrolysis of Selected Tropical Plant Wastes Catalyzed by a Magnetic Carbonaceous Acid with Microwave

    Science.gov (United States)

    Su, Tong-Chao; Fang, Zhen; Zhang, Fan; Luo, Jia; Li, Xing-Kang

    2015-12-01

    In this study, magnetic carbonaceous acids were synthesized by pyrolysis of the homogeneous mixtures of glucose and magnetic Fe3O4 nanoparticles, and subsequent sulfonation. The synthesis conditions were optimized to obtain a catalyst with both high acid density (0.75 mmol g-1) and strong magnetism [magnetic saturation, Ms = 19.5 Am2 kg-1]. The screened catalyst (C-SO3H/Fe3O4) was used to hydrolyze ball-milled cellulose in a microwave reactor with total reducing sugar (TRS) yield of 25.3% under the best conditions at 190 °C for 3.5 h. It was cycled for at least seven times with high catalyst recovery rate (92.8%), acid density (0.63 mmol g-1) and magnetism (Ms = 12.9 Am2 kg-1), as well as high TRS yield (20.1%) from the hydrolysis of ball-milled cellulose. The catalyst was further successfully tested for the hydrolysis of tropical biomass with high TRS and glucose yields of 79.8% and 58.3% for bagasse, 47.2% and 35.6% for Jatropha hulls, as well as 54.4% and 35.8% for Plukenetia hulls.

  13. Antioxidative Peptides Derived from Enzyme Hydrolysis of Bone Collagen after Microwave Assisted Acid Pre-Treatment and Nitrogen Protection

    Directory of Open Access Journals (Sweden)

    Jin Sun

    2010-11-01

    Full Text Available This study focused on the preparation method of antioxidant peptides by enzymatic hydrolysis of bone collagen after microwave assisted acid pre-treatment and nitrogen protection. Phosphoric acid showed the highest ability of hydrolysis among the four other acids tested (hydrochloric acid, sulfuric acid and/or citric acid. The highest degree of hydrolysis (DH was 9.5% using 4 mol/L phosphoric acid with a ratio of 1:6 under a microwave intensity of 510 W for 240 s. Neutral proteinase gave higher DH among the four protease tested (Acid protease, neutral protease, Alcalase and papain, with an optimum condition of: (1 ratio of enzyme and substrate, 4760 U/g; (2 concentration of substrate, 4%; (3 reaction temperature, 55 °C and (4 pH 7.0. At 4 h, DH increased significantly (P < 0.01 under nitrogen protection compared with normal microwave assisted acid pre-treatment hydrolysis conditions. The antioxidant ability of the hydrolysate increased and reached its maximum value at 3 h; however DH decreased dramatically after 3 h. Microwave assisted acid pre-treatment and nitrogen protection could be a quick preparatory method for hydrolyzing bone collagen.

  14. Reaction mechanism of the acidic hydrolysis of highly twisted amides: Rate acceleration caused by the twist of the amide bond.

    Science.gov (United States)

    Mujika, Jon I; Formoso, Elena; Mercero, Jose M; Lopez, Xabier

    2006-08-03

    We present an ab initio study of the acid hydrolysis of a highly twisted amide and a planar amide analogue. The aim of these studies is to investigate the effect that the twist of the amide bond has on the reaction barriers and mechanism of acid hydrolysis. Concerted and stepwise mechanisms were investigated using density functional theory and polarizable continuum model calculations. Remarkable differences were observed between the mechanism of twisted and planar amide, due mainly to the preference for N-protonation of the former and O-protonation of the latter. In addition, we were also able to determine that the hydrolytic mechanism of the twisted amide will be pH dependent. Thus, there is a preference for a stepwise mechanism with formation of an intermediate in the acid hydrolysis, whereas the neutral hydrolysis undergoes a concerted-type mechanism. There is a nice agreement between the characterized intermediate and available X-ray data and a good agreement with the kinetically estimated rate acceleration of hydrolysis with respect to analogous undistorted amide compounds. This work, along with previous ab initio calculations, describes a complex and rich chemistry for the hydrolysis of highly twisted amides as a function of pH. The theoretical data provided will allow for a better understanding of the available kinetic data of the rate acceleration of amides upon twisting and the relation of the observed rate acceleration with intrinsic differential reactivity upon loss of amide bond resonance.

  15. Extraction of cellulose nano-crystals from old corrugated container fiber using phosphoric acid and enzymatic hydrolysis followed by sonication.

    Science.gov (United States)

    Tang, Yanjun; Shen, Xiaochuang; Zhang, Junhua; Guo, Daliang; Kong, Fangong; Zhang, Nan

    2015-07-10

    Due to its amazing physicochemical properties and high environmental compatibility, cellulose nano-crystals (CNC) hold great promise for serving as a strategic platform for sustainable development. Now, there has been growing interest in the development of processes using waste or residual biomass as CNC source for addressing economic and environmental concerns. In the present work, a combined process involving phosphoric acid hydrolysis, enzymatic hydrolysis and sonication was proposed aiming to efficiently exact CNC from low-cost old corrugated container (OCC) pulp fiber. The effect of enzymatic hydrolysis on the yield and microstructure of resulting CNC was highlighted. Results showed that the enzymatic hydrolysis was effective in enhancing CNC yield after phosphoric acid hydrolysis. CNC was obtained with a yield of 23.98 wt% via the combined process with phosphoric acid concentration of 60 wt%, cellulase dosage of 2 mL (84 EGU) per 2g fiber and sonication intensity of 200 W. Moreover, the presence of enzymatic hydrolysis imparted the obtained CNC with improved dispersion, increased crystallinity and thermal stability.

  16. The effect of ethanol on the kinetics of lipase-mediated enantioselective esterification of 4-methyloctanoic acid and the hydrolysis of its ethyl ester

    NARCIS (Netherlands)

    Heinsman, N.W.J.T.; Valente, A.M.; Schmienk, H.G.F.; Padt, van der A.; Franssen, M.C.R.; Groot, de Æ.; Riet, van 't K.

    2001-01-01

    The Novozym 435? catalyzed esterification and hydrolysis reactions of 4-methyloctanoic acid (ethyl ester) were investigated. In both the hydrolysis and esterification reactions, the increase of ethanol concentration led to an increase in enantiomeric ratio (E). For hydrolysis of the ethyl ester, the

  17. The effect of ethanol on the kinetics of lipase-mediated enantioselective esterification of 4-methyloctanoic acid and the hydrolysis of its ethyl ester

    NARCIS (Netherlands)

    Heinsman, N.W.J.T.; Valente, A.M.; Schmienk, H.G.F.; Padt, van der A.; Franssen, M.C.R.; Groot, de Æ.; Riet, van 't K.

    2001-01-01

    The Novozym 435? catalyzed esterification and hydrolysis reactions of 4-methyloctanoic acid (ethyl ester) were investigated. In both the hydrolysis and esterification reactions, the increase of ethanol concentration led to an increase in enantiomeric ratio (E). For hydrolysis of the ethyl ester, the

  18. A relativistic density functional study of uranyl hydrolysis and complexation by carboxylic acids in aqueous solution

    Energy Technology Data Exchange (ETDEWEB)

    Ray, Rupashree Shyama

    2009-02-10

    In this work, the complexation of uranium in its most stable oxidation state VI in aqueous solution was studied computationally, within the framework of density functional (DF) theory. The thesis is divided into the following parts: Chapter 2 briefly summarizes the relevant general aspects of actinide chemistry and then focuses on actinide environmental chemistry. Experimental results on hydrolysis, actinide complexation by carboxylic acids, and humic substances are presented to establish a background for the subsequent discussion. Chapter 3 describes the computational method used in this work and the relevant features of the parallel quantum chemistry code PARAGAUSS employed. First, the most relevant basics of the applied density functional approach are presented focusing on relativistic effects. Then, the treatment of solvent effects, essential for an adequate modeling of actinide species in aqueous solution, will be introduced. At the end of this chapter, computational parameters and procedures will be summarized. Chapter 4 presents the computational results including a comparison to available experimental data. In the beginning, the mononuclear hydrolysis product of UO{sub 2}{sup 2+}, [UO{sub 2}OH]{sup +}, will be discussed. The second part deals with actinide complexation by carboxylate ligands. First of all the coordination number for uranylacetate will be discussed with respect to implications for the complexation of actinides by humic substances followed by the uranyl complexation of aromatic carboxylic acids in comparison to earlier results for aliphatic ones. In the end, the ternary uranyl-hydroxo-acetate are discussed, as models of uranyl humate complexation at ambient condition.

  19. Mild acid hydrolysis of fucoidan: characterization by electrophoresis and FT-Raman spectroscopy.

    Science.gov (United States)

    Pielesz, A; Biniaś, W; Paluch, J

    2011-09-27

    Along with proteins, lipids, water and minerals, polysaccharides are the main chemical compounds of which macroalgae are built. Among the chemical compounds now widely examined is fucoidan (fucan, fucosan, sulfate fucan or sulfated fucan), a fucose-containing sulfated polysaccharide. Fucoidans isolated from different species have been extensively studied because of their varied biological properties, including anticoagulant and antitumor effects. Methodology based on mild acid hydrolysis can be used as an efficient tool to study the relationship between molecular weight of the sulfated polysaccharides and their biological activities. Anticancer activity of fucoidans can be significantly enhanced by lowering their molecular weight only when they are depolymerized under mild conditions. In this study, fucoidan was identified during extraction with H(2)SO(4) and HCl; its presence was confirmed by FT-Raman spectroscopy in aqueous solution. In particular, shifts at 840cm(-1) were analysed, which are due to the presence of sulfate at the axial C-4 position, as were the shifts at about 811-809cm(-1), for which the sulfated fucoidan is responsible. Shifts of electrophoretic bands of fucoidan resulting from mild acid hydrolysis in H(2)SO(4) and HCl were also analysed. The analytical procedure was developed using apparatus for cellulose acetate membrane electrophoresis and this was supplemented by semi-quantitative analysis.

  20. Ultrasonic enhance acid hydrolysis selectivity of cellulose with HCl-FeCl3 as catalyst.

    Science.gov (United States)

    Li, Jinbao; Zhang, Xiangrong; Zhang, Meiyun; Xiu, Huijuan; He, Hang

    2015-03-06

    The effect of ultrasonic pretreatment coupled with HCl-FeCl3 catalyst was evaluated to hydrolyze cellulose amorphous regions. The ultrasonic pretreatment leads to cavitation that affects the morphology and microstructure of fibers, enhancing the accessibility of chemical reagent to the loosened amorphous regions of cellulose. In this work, Fourier transform infrared spectroscopy (FTIR) was used to identify characteristic absorption bands of the constituents and the crystallinity was evaluated by the X-ray diffraction (XRD) technique. The results indicated that appropriate ultrasonic pretreatment assisted with FeCl3 can enhance the acid hydrolysis of amorphous regions of cellulose, thus improving the crystallinity of the remaining hydrocellulose. It was observed that sonication samples that were pretreated for 300 W and 20 min followed by acid hydrolysis had maximum of 78.9% crystallinity. The crystallinity was 9.2% higher than samples that were not subjected to ultrasound. In addition, the average fines length decreased from 49 μm to 37 μm. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Hydrolysis of microcrystalline cellulose using functionalized Bronsted acidic ionic liquids - A comparative study.

    Science.gov (United States)

    Parveen, Firdaus; Patra, Tanmoy; Upadhyayula, Sreedevi

    2016-01-01

    Cellulose conversion to platform chemicals is required to meet the demands of increasing population and modernization of the world. Hydrolysis of microcrystalline cellulose was studied with SO3H, COOH and OH functionalized imidazole based ionic liquid using 1-butyl-3-methylimidazolium chloride [BMIM]Cl as a solvent. The influence of temperature, time, acidity of ionic liquids and catalyst loading was studied on hydrolysis reaction. The maximum %TRS yield 85%, was obtained at 100°C and 90min with 0.2g of SO3H functionalized ionic liquid. UV-vis spectroscopy using 4-nitro aniline as an indicator was performed to find out the Hammett function of ionic liquid and acidity trends are as follows: SO3H>COOH>OH. Density functional theory (DFT) calculations were performed to optimize the ionic liquid and their conjugate bases at B3LYP 6-311G++ (d, p) level using Gaussian 09 program. Theoretical findings are in agreement with the experimental results. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Recovery of isoflavone aglycones from soy whey wastewater using foam fractionation and acidic hydrolysis.

    Science.gov (United States)

    Liu, Wei; Zhang, Hui Xin; Wu, Zhao Liang; Wang, Yan Ji; Wang, Lian Jie

    2013-07-31

    The purpose of this work was to recover isoflavone aglycones from industrial soy whey wastewater, where the isoflavone aglycones mainly existed in the form of β-glycosides. First, foam fractionation was used for effectively concentrating the total soy isoflavones, including isoflavone aglycones and β-glycosides, from the wastewater. Fourier transform infrared spectroscopy indicated the existence of complexes of soy isoflavones and soy proteins. When soy proteins were used as the collectors, a high enrichment ratio of 3.68 was obtained under the optimal operating conditions of temperature of 50 °C, pH of 5.0, volumetric air flow rate of 100 mL/min, and loading liquid height of 400 mm. Subsequently, acidic hydrolysis was used for hydrolyzing β-glycosides in the foamate into aglycones. Using response surface methodology, a hydrolytic percentage could reach 96% under the optimum hydrolysis conditions of hydrolytic temperature of 80 °C, hydrochloric acid concentration of 1.37 mol/L, and hydrolytic time of 90 min.

  3. Assessment on proximate composition, dietary fiber, phytic acid and protein hydrolysis of germinated Ecuatorian brown rice.

    Science.gov (United States)

    Cáceres, Patricio J; Martínez-Villaluenga, Cristina; Amigo, Lourdes; Frias, Juana

    2014-09-01

    Germinated brown rice (GBR) is considered healthier than brown rice (BR) but its nutritive value has been hardly studied. Since nutritive quality of GBR depends on genetic diversity and germination conditions, six Ecuadorian BR varieties were germinated at 28 and 34 ºC for 48 and 96 h in darkness and proximate composition, dietary fiber fractions, phytic acid content as well as degree of protein hydrolysis and peptide content were studied. Protein, lipids, ash and available carbohydrate ranged 7.3-10.4%, 2.0-4.0%, 0.8-1.5% and 71.6 to 84.0%, respectively, in GBR seedlings. Total dietary fiber increased during germination (6.1-13.6%), with a large proportion of insoluble fraction, while phytic acid was reduced noticeably. In general, protein hydrolysis occurred during germination was more accused at 28 ºC for 48 h. These results suggest that GBR can be consumed directly as nutritive staple food for a large population worldwide contributing to their nutritional requirements.

  4. Hydrolysis optimization and characterization study of preparing fatty acids from Jatropha curcas seed oil

    Directory of Open Access Journals (Sweden)

    Salimon Jumat

    2011-11-01

    Full Text Available Abstract Background Fatty acids (FAs are important as raw materials for the biotechnology industry. Existing methods of FAs production are based on chemical methods. In this study potassium hydroxide (KOH-catalyzed reactions were utilized to hydrolysis Jatropha curcas seed oil. Results The parameters effect of ethanolic KOH concentration, reaction temperature, and reaction time to free fatty acid (FFA% were investigated using D-Optimal Design. Characterization of the product has been studied using Fourier transforms infrared spectroscopy (FTIR, gas chromatography (GC and high performance liquid chromatography (HPLC. The optimum conditions for maximum FFA% were achieved at 1.75M of ethanolic KOH concentration, 65°C of reaction temperature and 2.0 h of reaction time. Conclusions This study showed that ethanolic KOH concentration was significant variable for J. curcas seed oil hydrolysis. In a 18-point experimental design, FFA% of hydrolyzed J. curcas seed oil can be raised from 1.89% to 102.2%, which proved by FTIR and HPLC.

  5. Effect of hot acid hydrolysis and hot chlorine dioxide stage on bleaching effluent biodegradability.

    Science.gov (United States)

    Gomes, C M; Colodette, J L; Delantonio, N R N; Mounteer, A H; Silva, C M

    2007-01-01

    The hot acid hydrolysis followed by chlorine dioxide (A/D*) and hot chlorine dioxide (D*) technologies have proven very useful for bleaching of eucalyptus kraft pulp. Although the characteristics and biodegradability of effluents from conventional chlorine dioxide bleaching are well known, such information is not yet available for effluents derived from hot acid hydrolysis and hot chorine dioxide bleaching. This study discusses the characteristics and biodegradability of such effluents. Combined whole effluents from the complete sequences DEpD, D*EpD, A/D*EpD and ADEpD, and from the pre-bleaching sequences DEp, D*Ep, A/D*Ep and ADEp were characterized by quantifying their colour, AOX and organic load (BOD, COD, TOC). These effluents were also evaluated for their treatability by simulation of an activated sludge system. It was concluded that treatment in the laboratory sequencing batch reactor was efficient for removal of COD, BOD and TOC of all effluents. However, colour increased after biological treatment, with the greatest increase found for the effluent produced using the AD technology. Biological treatment was less efficient at removing AOX of effluents from the sequences with D*, A/D* and AD as the first stages, when compared to the reference D stage; there was evidence of the lower treatability of these organochlorine compounds from these sequences.

  6. EFFECT OF INHIBITORS ON ENZYMATIC HYDROLYSIS AND SIMULTANEOUS SACCHARIFICATION FERMENTATION FOR LACTIC ACID PRODUCTION FROM STEAM EXPLOSION PRETREATED LESPEDEZA STALKS

    Directory of Open Access Journals (Sweden)

    Yue Feng,

    2012-06-01

    Full Text Available The effects on both cellulose conversion rate and lactic acid yield were studied by adding inhibitors, including formic acid, acetic acid, furfural, and vanillin into the hydrolysate of steam-pretreated Lespedeza stalks. The results suggest that formic acid has a significant influence on the enzyme activity and poisoned bacterial cells, resulting in the reduction of cellulose conversion rate and lactic acid yield by 21% and 16.4%, respectively. Acetic acid showed a strong inhibition on simultaneous saccharification fermentation (SSF process, but little effect on enzymatic hydrolysis. Hydrolysis and SSF were less affected by furfural and vanillin compared with weak acids. The lactic acid yield of Lespedeza stalks rinsed with water increased from 64.0% to 89.4%, and the time to reach the maximum concentration was shortened from 96 hours to 48 hours when compared with the unwashed materials.

  7. Effect of acid hydrolysis and fungal biotreatment on agro-industrial wastes for obtainment of free sugars for bioethanol production

    Directory of Open Access Journals (Sweden)

    T.S. El-Tayeb

    2012-12-01

    Full Text Available This study was designed to evaluate selected chemical and microbiological treatments for the conversion of certain local agro-industrial wastes (rice straw, corn stalks, sawdust, sugar beet waste and sugarcane bagasse to ethanol. The chemical composition of these feedstocks was determined. Conversion of wastes to free sugars by acid hydrolysis varied from one treatment to another. In single-stage dilute acid hydrolysis, increasing acid concentration from 1 % (v/v to 5 % (v/v decreased the conversion percentage of almost all treated agro-industrial wastes. Lower conversion percentages for some treatments were obtained when increasing the residence time from 90 to 120min. The two-stage dilute acid hydrolysis by phosphoric acid (1.0 % v/v followed by sulphuric acid (1.0 % v/v resulted in the highest conversion percentage (41.3 % w/w on treated sugar beet waste. This treatment when neutralized, amended with some nutrients and inoculated with baker's yeast, achieved the highest ethanol concentration (1.0 % v/v. Formation of furfural and hydroxymethylfurfural (HMF were functions of type of acid hydrolysis, acid concentration, residence time and feedstock type. The highest bioconversion of 5 % wastes (37.8 % w/w was recorded on sugar beet waste by Trichoderma viride EMCC 107. This treatment when followed by baker's yeast fermentation, 0.41 % (v/v ethanol and 8.2 % (v/w conversion coefficient were obtained.

  8. Enhancing the enzymatic hydrolysis of lignocellulosic biomass by increasing the carboxylic acid content of the associated lignin.

    Science.gov (United States)

    Nakagame, Seiji; Chandra, Richard P; Kadla, John F; Saddler, Jack N

    2011-03-01

    To assess the effects that the physical and chemical properties of lignin might have on the enzymatic hydrolysis of pretreated lignocellulosic substrates, protease treated lignin (PTL) and cellulolytic enzyme lignin (CEL) fractions, isolated from steam and organosolv pretreated corn stover, poplar, and lodgepole pine, were prepared and characterized. The adsorption of cellulases to the isolated lignin preparations corresponded to a Langmuir adsorption isotherm. It was apparent that, rather than the physical properties of the isolated lignin, the carboxylic acid functionality of the isolated lignin, as determined by FTIR and NMR spectroscopy, had much more of an influence when lignin was added to typical hydrolysis of pure cellulose (Avicel). An increase in the carboxylic content of the lignin preparation resulted in an increased hydrolysis yield. These results suggested that the carboxylic acids within the lignin partially alleviate non-productive binding of cellulases to lignin. To try to confirm this possible mechanism, dehydrogenative polymers (DHP) of monolignols were synthesized from coniferyl alcohol (CA) and ferulic acid (FA), and these model compounds were added to a typical enzymatic hydrolysis of Avicel. The DHP from FA, which was enriched in carboxylic acid groups compared with the DHP from CA, adsorbed a lower mount of cellulases and did not decrease hydrolysis yields when compared to the DHP from CA, which decreased the hydrolysis of Avicel by 8.4%. Thus, increasing the carboxylic acid content of the lignin seemed to significantly decrease the non-productive binding of cellulases and consequently increased the enzymatic hydrolysis of the cellulose. Copyright © 2010 Wiley Periodicals, Inc.

  9. Theoretical study of the alkaline hydrolysis of an aza-β-lactam derivative of clavulanic acid

    Science.gov (United States)

    Garcías, Rafael C.; Coll, Miguel; Donoso, Josefa; Muñoz, Francisco

    2003-04-01

    DFT calculations based on the hybrid functional B3LYP/6-31+G * were used to study the alkaline hydrolysis of an aza-clavulanic acid, which results from the substitution of the carbon atom at position 6 in clavulanic acid by a nitrogen atom. The presence of the nitrogen atom endows the compound with special properties; in fact, once formed, the tetrahedral intermediate can evolve with cleavage of the N 4-C 7 or N 6-C 7 bond, which obviously leads to different reaction products. These differential bond cleavages may play a central role in the inactivation of β-lactamases, so the compound may be a powerful inactivator of these enzymes.

  10. Hydrolysis of Miscanthus for bioethanol production using dilute acid presoaking combined with wet explosion pre-treatment and enzymatic treatment

    DEFF Research Database (Denmark)

    Sørensen, Annette; Teller, Philip Johan; Hilstrøm, Troels

    2008-01-01

    xylose prior to wet explosion. The acid presoaking extracted 63.2% xylose and 5.2% glucose. Direct enzymatic hydrolysis of the presoaked biomass was found to give only low sugar yields of 24-26% glucose. Wet explosion is a pre-treatment method that combines wet-oxidation and steam explosion. The effect......Miscanthus is a high yielding bioenergy crop. In this study we used acid presoaking, wet explosion, and enzymatic hydrolysis to evaluate the combination of the different pre-treatment methods for bioethanol production with Miscanthus. Acid presoaking is primarily carried out in order to remove...... of wet explosion on non-presoaked and presoaked Miscanthus was investigated using both atmospheric air and hydrogen peroxide as the oxidizing agent. All wet explosion pre-treatments showed to have a disrupting effect on the lignocellulosic biomass, making the sugars accessible for enzymatic hydrolysis...

  11. Monosaccharide-NAIM Derivatives for D-, L-Configurational Analysis

    Directory of Open Access Journals (Sweden)

    Chunchi Lin

    2011-01-01

    Full Text Available The D-, L-enantiomeric pairs of common monosaccharides (xylose, ribose, rhamnose, arabinose, fucose, glucose, mannose, galactose, N-acetylgalactosamine, glucuronic acid and galacturonic acid were derivatized with 2,3-naphthalenediamine to form the corresponding D-, L-aldo-NAIM derivatives. A simple and facile capillary electrophoretic method was established for sugar composition analysis by simultaneously determining the migration times of these aldo-NAIMs using borate buffer at high pH (100 mM, pH 9.0. The methodology is also applicable to sialic acid (ketose monosaccharides. The quantitation level of the proposed method was in the 10~500 ppm range and the LOD was 1 ppm. The enantioseparation of D, L pairs of aldo-NAIMs were also achieved by using modified sulfated-a-cyclodextrin as the chiral selector in phosphate buffer (300 mM, pH 3.0. In addition, the combination by reductive amination of amino-aldo-NAIM agent and D-, L-enantiomeric pairs of monosaccharides formed a diastereomeric pair for saccharide configuration analysis. Aldo-NAIM derivatives are thus shown to be rapid and efficient agents for analyzing saccharide compositions and configurations with good linearity and short analysis times via capillary electrophoresis.

  12. Clay ingestion enhances intestinal triacylglycerol hydrolysis and non-esterified fatty acid absorption.

    Science.gov (United States)

    Habold, Caroline; Reichardt, François; Le Maho, Yvon; Angel, Fabielle; Liewig, Nicole; Lignot, Jean-Hervé; Oudart, Hugues

    2009-07-01

    Consumption by animals and humans of earthy materials such as clay is often related to gut pathologies. Our aim was to determine the impact of kaolinite ingestion on glucose and NEFA transport through the intestinal mucosa. The expression of hexose transporters (Na/glucose co-transporter 1 (SGLT1), GLUT2, GLUT5) and of proteins involved in NEFA absorption (fatty acid transporter/cluster of differentiation 36 (FAT/CD36), fatty acid transport protein 4 (FATP4) and liver fatty acid binding protein (L-FABP)) was measured (1) in rats whose jejunum was perfused with a solution of kaolinite, and (2) in rats who ate spontaneously kaolinite pellets during 7 and 28 d. Also, we determined TAG and glucose absorption in the kaolinite-perfused group, and pancreatic lipase activity, gastric emptying and intestinal transit in rats orally administered with kaolinite. Glucose absorption was not affected by kaolinite perfusion or ingestion. However, kaolinite induced a significant increase in intestinal TAG hydrolysis and NEFA absorption. The cytoplasmic expression of L-FABP and FATP4 also increased due to kaolinite ingestion. NEFA may enter the enterocytes via endocytosis mainly since expression of NEFA transporters in the brush-border membrane was not affected by kaolinite. After uptake, rapid binding of NEFA by L-FABP and FATP4 could act as an intracellular NEFA buffer to prevent NEFA efflux. Increased TAG hydrolysis and NEFA absorption may be due to the adsorption properties of clay and also because kaolinite ingestion caused a slowing down of gastric emptying and intestinal transit.

  13. Carbon allocation in ectomycorrhizas: identification and expression analysis of an Amanita muscaria monosaccharide transporter.

    Science.gov (United States)

    Nehls, U; Wiese, J; Guttenberger, M; Hampp, R

    1998-03-01

    Ectomycorrhizas are formed between certain soil fungi and fine roots of predominantly woody plants. An important feature of this symbiosis is the supply of plant-derived carbohydrates to the fungus. As a first step toward a better understanding of the molecular basis of this process, we cloned a monosaccharide transporter from the ectomycorrhizal fungus Amanita muscaria. Degenerate oligonucleotide primers were designed to match conserved regions from known fungal sugar transporters. A cDNA fragment of the transporter was obtained from mycorrhizal mRNA by reverse transcription-polymerase chain reaction. This fragment was used to identify a clone (AmMst1) encoding the entire monosaccharide transporter in a Picea abies/A. muscaria mycorrhizal cDNA library. The cDNA codes for an open reading frame of 520 amino acids, showing best homology to a Neurospora crassa monosaccharide transporter. The function of AmMST1 as monosaccharide transporter was confirmed by heterologous expression of the cDNA in a Schizosaccharomyces pombe mutant lacking a monosaccharide uptake system. AmMst1 was constitutively expressed in fungal hyphae under all growth conditions. Nevertheless, in mycorrhizas as well as in hyphae grown at monosaccharide concentrations above 5 mM, the amount of AmMst1 transcript increased fourfold. We therefore suggest that AmMst1 is upregulated in ectomycorrhizas by a monosaccharide-controlled mechanism.

  14. Bioethanol Production from Coconut Fiber Using Alkaline Pretreatment and Acid Hydrolysis Method

    Directory of Open Access Journals (Sweden)

    Asyeni Miftahul Jannah

    2015-01-01

    Full Text Available Supporting Indonesia government program to decrease fuel consumption, using renewable energy such of bioethanol is one of the best ways. This research was done in order to utilize agriculture waste (coconut fiber as raw material to produce bioetanol. However, coconut fiber contents lignin that will inhibit conversion process of glucose into ethanol. In this research, pretreatment steps aim to release and breakdown lignin in coconut fiber. Pretreatment was conducted by using alkaline method with 3% Sodium Hydroxide solution. Hydrolysis method was used to produce glucose by using Sulfuric Acid solution with various concentrations (1%, 2%, 3%, and 4 % while in fermentation process used Saccharomyces cerevisiae with various times (5, 7, 9, and 11 days and distillation used to get pure product of bioethanol. The results showed that higher H2SO4 concentration using on hydrolysis process made more glucose converted to bioethanol. The highest bioethanol content produced was 5.9420% from sample of 4% H2SO4 in 7 days of fermentation.

  15. Methane production from acid hydrolysates of Agave tequilana bagasse: evaluation of hydrolysis conditions and methane yield.

    Science.gov (United States)

    Arreola-Vargas, Jorge; Ojeda-Castillo, Valeria; Snell-Castro, Raúl; Corona-González, Rosa Isela; Alatriste-Mondragón, Felipe; Méndez-Acosta, Hugo O

    2015-04-01

    Evaluation of diluted acid hydrolysis for sugar extraction from cooked and uncooked Agave tequilana bagasse and feasibility of using the hydrolysates as substrate for methane production, with and without nutrient addition, in anaerobic sequencing batch reactors (AnSBR) were studied. Results showed that the hydrolysis over the cooked bagasse was more effective for sugar extraction at the studied conditions. Total sugars concentration in the cooked and uncooked bagasse hydrolysates were 27.9 g/L and 18.7 g/L, respectively. However, 5-hydroxymethylfurfural was detected in the cooked bagasse hydrolysate, and therefore, the uncooked bagasse hydrolysate was selected as substrate for methane production. Interestingly, results showed that the AnSBR operated without nutrient addition obtained a constant methane production (0.26 L CH4/g COD), whereas the AnSBR operated with nutrient addition presented a gradual methane suppression. Molecular analyses suggested that methane suppression in the experiment with nutrient addition was due to a negative effect over the archaeal/bacterial ratio.

  16. Enantioselective Hydrolysis of Amino Acid Esters Promoted by Bis(β-cyclodextrin) Copper Complexes.

    Science.gov (United States)

    Xue, Shan-Shan; Zhao, Meng; Ke, Zhuo-Feng; Cheng, Bei-Chen; Su, Hua; Cao, Qian; Cao, Zhen-Kun; Wang, Jun; Ji, Liang-Nian; Mao, Zong-Wan

    2016-02-26

    It is challenging to create artificial catalysts that approach enzymes with regard to catalytic efficiency and selectivity. The enantioselective catalysis ranks the privileged characteristic of enzymatic transformations. Here, we report two pyridine-linked bis(β-cyclodextrin) (bisCD) copper(II) complexes that enantioselectively hydrolyse chiral esters. Hydrolytic kinetic resolution of three pairs of amino acid ester enantiomers (S1-S3) at neutral pH indicated that the "back-to-back" bisCD complex CuL(1) favoured higher catalytic efficiency and more pronounced enantioselectivity than the "face-to-face" complex CuL(2). The best enantioselectivity was observed for N-Boc-phenylalanine 4-nitrophenyl ester (S2) enantiomers promoted by CuL(1), which exhibited an enantiomer selectivity of 15.7. We observed preferential hydrolysis of L-S2 by CuL(1), even in racemic S2, through chiral high-performance liquid chromatography (HPLC). We demonstrated that the enantioselective hydrolysis was related to the cooperative roles of the intramolecular flanking chiral CD cavities with the coordinated copper ion, according to the results of electrospray ionization mass spectrometry (ESI-MS), inhibition experiments, rotating-frame nuclear Overhauser effect spectroscopy (ROESY), and theoretical calculations. Although the catalytic parameters lag behind the level of enzymatic transformation, this study confirms the cooperative effect of the first and second coordination spheres of artificial catalysts in enantioselectivity and provides hints that may guide future explorations of enzyme mimics.

  17. Enantioselective Hydrolysis of Amino Acid Esters Promoted by Bis(β-cyclodextrin) Copper Complexes

    Science.gov (United States)

    Xue, Shan-Shan; Zhao, Meng; Ke, Zhuo-Feng; Cheng, Bei-Chen; Su, Hua; Cao, Qian; Cao, Zhen-Kun; Wang, Jun; Ji, Liang-Nian; Mao, Zong-Wan

    2016-02-01

    It is challenging to create artificial catalysts that approach enzymes with regard to catalytic efficiency and selectivity. The enantioselective catalysis ranks the privileged characteristic of enzymatic transformations. Here, we report two pyridine-linked bis(β-cyclodextrin) (bisCD) copper(II) complexes that enantioselectively hydrolyse chiral esters. Hydrolytic kinetic resolution of three pairs of amino acid ester enantiomers (S1–S3) at neutral pH indicated that the “back-to-back” bisCD complex CuL1 favoured higher catalytic efficiency and more pronounced enantioselectivity than the “face-to-face” complex CuL2. The best enantioselectivity was observed for N-Boc-phenylalanine 4-nitrophenyl ester (S2) enantiomers promoted by CuL1, which exhibited an enantiomer selectivity of 15.7. We observed preferential hydrolysis of L-S2 by CuL1, even in racemic S2, through chiral high-performance liquid chromatography (HPLC). We demonstrated that the enantioselective hydrolysis was related to the cooperative roles of the intramolecular flanking chiral CD cavities with the coordinated copper ion, according to the results of electrospray ionization mass spectrometry (ESI-MS), inhibition experiments, rotating-frame nuclear Overhauser effect spectroscopy (ROESY), and theoretical calculations. Although the catalytic parameters lag behind the level of enzymatic transformation, this study confirms the cooperative effect of the first and second coordination spheres of artificial catalysts in enantioselectivity and provides hints that may guide future explorations of enzyme mimics.

  18. Adsorption and hydrolysis of isocyanic acid on TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Piazzesi, Gaia; Kroecher, Oliver; Elsener, Martin; Wokaun, Alexander [Paul Scherrer Institute PSI, CH-5232 Villigen (Switzerland)

    2006-05-15

    The interaction of isocyanic acid (HNCO) with titania in the anatase modification has been investigated by means of DRIFT spectroscopy and TPD experiments. HNCO adsorbs dissociatively on TiO{sub 2} to yield isocyanate (NCO) groups, bound to Ti{sup 4+} sites, and hydroxyl (OH) groups. The stability of these NCO groups decreases with increasing temperatures, and at T>200{sup o}C they are very easily removed from the surface. In the presence of water, the hydrolysis of the NCO species to ammonia is also fostered by elevating the temperature. Moreover, HNCO adsorption on a sample previously exposed to ammonia revealed that competitive adsorption occurs on the surface. The catalytic activity of TiO{sub 2} for the hydrolyis of HNCO was investigated in a micro plug-flow reactor and correlated with the stability and reactivity of the isocyanate species found by DRIFT spectroscopy. The results are discussed in view of the role of the HNCO hydrolysis in the selective catalytic reduction (SCR) of diesel NO{sub x} emissions with urea (urea-SCR process). (author)

  19. Application of high throughput pretreatment and co-hydrolysis system to thermochemical pretreatment. Part 1: dilute acid.

    Science.gov (United States)

    Gao, Xiadi; Kumar, Rajeev; DeMartini, Jaclyn D; Li, Hongjia; Wyman, Charles E

    2013-03-01

    Because conventional approaches for evaluating sugar release from the coupled operations of pretreatment and enzymatic hydrolysis are extremely time and material intensive, high throughput (HT) pretreatment and enzymatic hydrolysis systems have become vital for screening large numbers of lignocellulosic biomass samples to identify feedstocks and/or processing conditions that significantly improve performance and lower costs. Because dilute acid pretreatment offers many important advantages in rendering biomass highly susceptible to subsequent enzymatic hydrolysis, a high throughput pretreatment and co-hydrolysis (HTPH) approach was extended to employ dilute acid as a tool to screen for enhanced performance. First, a single-step neutralization and buffering method was developed to allow effective enzymatic hydrolysis of the whole pretreated slurry. Switchgrass and poplar were then pretreated with 0.5% and 1% acid loadings at a 5% solids concentration, the resulting slurry conditioned with the buffering approach, and the entire mixture enzymatically hydrolyzed. The resulting sugar yields demonstrated that single-step neutralizing and buffering was capable of adjusting the pH as needed for enzymatic saccharification, as well as overcoming enzyme inhibition by compounds released in pretreatment. In addition, the effects of pretreatment conditions and biomass types on susceptibility of pretreated substrates to enzymatic conversion were clearly discernible, demonstrating the method to be a useful extension of HTPH systems.

  20. The acid-catalyzed hydrolysis of an α-pinene-derived organic nitrate: kinetics, products, reaction mechanisms, and atmospheric impact

    Science.gov (United States)

    Rindelaub, Joel D.; Borca, Carlos H.; Hostetler, Matthew A.; Slade, Jonathan H.; Lipton, Mark A.; Slipchenko, Lyudmila V.; Shepson, Paul B.

    2016-12-01

    The production of atmospheric organic nitrates (RONO2) has a large impact on air quality and climate due to their contribution to secondary organic aerosol and influence on tropospheric ozone concentrations. Since organic nitrates control the fate of gas phase NOx (NO + NO2), a byproduct of anthropogenic combustion processes, their atmospheric production and reactivity is of great interest. While the atmospheric reactivity of many relevant organic nitrates is still uncertain, one significant reactive pathway, condensed phase hydrolysis, has recently been identified as a potential sink for organic nitrate species. The partitioning of gas phase organic nitrates to aerosol particles and subsequent hydrolysis likely removes the oxidized nitrogen from further atmospheric processing, due to large organic nitrate uptake to aerosols and proposed hydrolysis lifetimes, which may impact long-range transport of NOx, a tropospheric ozone precursor. Despite the atmospheric importance, the hydrolysis rates and reaction mechanisms for atmospherically derived organic nitrates are almost completely unknown, including those derived from α-pinene, a biogenic volatile organic compound (BVOC) that is one of the most significant precursors to biogenic secondary organic aerosol (BSOA). To better understand the chemistry that governs the fate of particle phase organic nitrates, the hydrolysis mechanism and rate constants were elucidated for several organic nitrates, including an α-pinene-derived organic nitrate (APN). A positive trend in hydrolysis rate constants was observed with increasing solution acidity for all organic nitrates studied, with the tertiary APN lifetime ranging from 8.3 min at acidic pH (0.25) to 8.8 h at neutral pH (6.9). Since ambient fine aerosol pH values are observed to be acidic, the reported lifetimes, which are much shorter than that of atmospheric fine aerosol, provide important insight into the fate of particle phase organic nitrates. Along with rate constant

  1. Hydrolysis and transesterification of parabens in an aqueous solution in the presence of glycerol and boric acid.

    OpenAIRE

    Oldrich Farsa; Jan Subert; Marie Marečková

    2016-01-01

    In a solution containing 0.067% methylparaben, 0.033% propylparaben, 3.4% glycerol and 2.0% boric acid, concentrations of both parabens, 4 hydroxybenzoic acid and 2,3-dihydroxypropyl 4-hydroxybenzoate were monitored for up to 68 months storage. 4-hydroxybenzoic acid is the main hydrolysis product of parabens, while 2,3-dihydroxypropyl 4 hydroxybenzoate was proposed as the main product of transesterification of parabens with glycerol. Results of an HPLC evaluation of parabens, 4-hydroxybenzoic...

  2. DETERMINATION OF AMINO ACIDS IN TWO POLYSIPHONIA SPECIES AND STUDY OF ENZYMATIC HYDROLYSIS METHOD

    Institute of Scientific and Technical Information of China (English)

    张立新; 范晓; 魏玉西

    2002-01-01

    The total content of the rich amino acids in two common red algae, Polysiphoni a urceolata and Polysiphonia japonica growing in the Qingdao seashore were d etermi ned. The algae powder was hydrolyzed by 6 mol/L HCl at 110℃ for 48 h and determ ined by amino acid analyzer. The content was 25.35% and 24.16%, respectively, mu ch higher than that of some other species. In addition, a nutritive liquid with abundant amino acids was prepared (by the enzymatic hydrolysis method using Po lys iphonia urceolata) as raw material for a kind of health beverage. The dried se aweed was decolored by 0.25% KMnO4 and 0.5% active carbon, then enzymalized. In the selection of enzymalizing condition, the orthogonal experimental design w as used. Four factors including kinds of enzyme, quantity of enzyme, temperature and time were studied at 3 leve ls. According to the orthogonal design results, we can choose an optimal condition: hydrolyzing at 45℃ by neutr al proteinase (0.25%, w/w) for 2 h, adjusting pH to 8.5, then adding trypsin (0.25%, w/w) and hydrolyzing for 2 h. F inally the above solution was alkalized by NaOH and neutralized by casein. After the hydrolyzed liquid was fil tered and concentrated, suitable additives were added. The final products contain rich amino acids.

  3. Lignin hydrolysis and phosphorylation mechanism during phosphoric acid-acetone pretreatment: a DFT study.

    Science.gov (United States)

    Qin, Wu; Wu, Lingnan; Zheng, Zongming; Dong, Changqing; Yang, Yongping

    2014-12-18

    The study focused on the structural sensitivity of lignin during the phosphoric acid-acetone pretreatment process and the resulting hydrolysis and phosphorylation reaction mechanisms using density functional theory calculations. The chemical stabilities of the seven most common linkages (β-O-4, β-β, 4-O-5, β-1, 5-5, α-O-4, and β-5) of lignin in H3PO4, CH3COCH3, and H2O solutions were detected, which shows that α-O-4 linkage and β-O-4 linkage tend to break during the phosphoric acid-acetone pretreatment process. Then α-O-4 phosphorylation and β-O-4 phosphorylation follow a two-step reaction mechanism in the acid treatment step, respectively. However, since phosphorylation of α-O-4 is more energetically accessible than phosphorylation of β-O-4 in phosphoric acid, the phosphorylation of α-O-4 could be controllably realized under certain operational conditions, which could tune the electron and hole transfer on the right side of β-O-4 in the H2PO4- functionalized lignin. The results provide a fundamental understanding for process-controlled modification of lignin and the potential novel applications in lignin-based imprinted polymers, sensors, and molecular devices.

  4. DETERMINATION OF AMINO ACIDS IN TWO POLYSIPHONIA SPECIES AND STUDY OF ENZYMATIC HYDROLYSIS METHOD

    Institute of Scientific and Technical Information of China (English)

    张立新; 范晓; 魏玉西

    2002-01-01

    The total content ot the nch amino acids in two common red algae, Potystpnoma urceolata and Polysiphonia japonica growing in the Qingdao seashore were determined. The algae powder was hydrolyzed by 6 mol/L HC1 at 110℃ for 48 h and determined by amino acid analyzer. The content was 25.35% and 24.16% , respectively, much higher than that of some other species. In addition, a nutritive liquid with abundant amino acids was prepared (by the enzymatic hydrolysis method using Polysiphonia urceolata ) as raw material for a kind of health beverage. The dried seaweed was decolored by 0.25% KMnO4 and 0.5% active carbon, then enzymalized. In the selection of enzymalizing condition, the orthogonal experimental design was used. Four factors including kinds of enzyme, quantity of enzyme, temperature and time were studied at 3 levels. According to the orthogonal design results, we can choose an optimal condition: hydrolyzing at 45℃ by neutral proteinase (0.25% , w/w) for 2 h, adjusting pH to 8.5, then adding trypsin (0.25% , w/w) and hydrolyzing for 2 h. Finally the above solution was alkalized by NaOH and neutralized by casein. After the hydrolyzed liquid was filtered and concentrated, suitable additives were added. The final products contain rich amino acids.

  5. Cellulose nanocrystals prepared via formic acid hydrolysis followed by TEMPO-mediated oxidation.

    Science.gov (United States)

    Li, Bin; Xu, Wenyang; Kronlund, Dennis; Määttänen, Anni; Liu, Jun; Smått, Jan-Henrik; Peltonen, Jouko; Willför, Stefan; Mu, Xindong; Xu, Chunlin

    2015-11-20

    Cellulose nanocrystals (CNCs) as a renewable and biodegradable nanomaterial have wide application value. In this work, CNCs were extracted from bleached chemical pulp using two stages of isolation (i.e. formic acid (FA) hydrolysis and 2,2,6,6-tetramethyl-piperidine-1-oxyl (TEMPO) mediated oxidation) under mild conditions. In the first stage, FA was used to remove hemicellulose, swell cellulose fibers, and release CNCs. The FA could be readily recovered and reused. In the second stage, the CNCs isolated by FA were further modified by TEMPO-mediated oxidation to increase the surface charge of CNCs. It was found that the modified CNCs with more ordered crystal structure and higher surface charge had better redispersibility and higher viscosity in aqueous phase. Therefore, the modified CNCs could be more effective when used as rheology modifier in the fields of water based coating, paint, food etc. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Study on treatment technology of wastewater from hydrolysis of acid oil

    Science.gov (United States)

    Li, Yuejin; Lin, Zhiyong; Han, Yali

    2017-06-01

    In this paper, the degumming of ferric chloride, calcium hydroxide after the removal of acid acidification hydrolysis of waste oil as raw material, through the treatment process to purify the wastewater. Choose different chemical additives, investigation of different temperature, pH value and other factors, find the best extraction condition. Through the orthogonal test of sodium carbonate, sodium oxalate, barium carbonate, compared with three kinds of chemical additives. The best chemical assistant is sodium carbonate, the best treatment temperature is 80 degrees Celsius, pH value is 8.0. After the reaction, the content of calcium and iron ions were determined by suitable methods. The removal rate of calcium ion is 98%, the removal rate of iron ion is 99%, and the effect of calcium and iron ion precipitation on the subsequent evaporation operation is reduced. Finally, the comparison is made to clarify the Dilute Glycerol water solution.

  7. Enhanced hydrolysis of bamboo biomass by chitosan based solid acid catalyst with surfactant addition in ionic liquid.

    Science.gov (United States)

    Si, Wenqing; Li, Yichen; Zheng, Jie; Wei, Shun'an; Wang, Dan

    2017-10-15

    Surfactants were used for the hydrolysis of bamboo biomass to enhance lignocellulose hydrolysis. Tween 80, polyethylene glycol 4000 (PEG 4000), and sodium dodecyl sulfate (SDS) were tested as surfactants for improving the bamboo hydrolysis with a novel sulfonated cross-linked chitosan solid acid catalyst (SCCAC) in ionic liquid (IL). Compared to the use of only SCCAC in 1-Butyl-3-methylimidazolium chloride ([BMIM]Cl), the surfactants facilitated hydrolysis and improved the yield of total reducing sugar (TRS) under the same conditions. Tween 80 was the most effective surfactant, with a TRS yield of 68.01% achieved at 120°C after 24h. Surfactants broke the lignocellulose structure, promoted lignin removal, and increased positive interactions between cellulose and the catalyst, which were favorable for hydrolysis. This novel surfactant-assisted hydrolysis strategy with SCCAC and IL as the solvent demonstrated a promise for the large-scale transformation of biomass into biofuels and bioproducts. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Dextran and 5-aminosalicylic acid (5-ASA) conjugates: synthesis, characterisation and enzymic hydrolysis.

    Science.gov (United States)

    Ahmad, Shavej; Tester, Richard F; Corbett, Alistair; Karkalas, John

    2006-11-27

    Mesalamine (5-aminosalicylic acid) is the drug of choice for the treatment of Crohn's disease. A scheme for the synthesis of 5-aminosalicylic acid (5-ASA) conjugates of dextrans was developed with a focus on Crohn's disease applications. Dextrans were oxidised using sodium periodate (NaIO(4)), where the aldehyde groups formed were coupled with the alpha-amino (-NH(2)) group of 5-ASA. The resulting imine bonds were unstable in water and were consequently reduced to secondary amine groups. The effects of different aspects of the conjugation reaction were studied. These included the following: the molecular weight of the dextrans, the molar proportion of NaIO(4) to the dextrans (for periodate oxidation), the pH of the conjugation solutions, the ratio 5-ASA to oxidised polysaccharide and the relationship between the degree of conjugation and the amount of enzyme hydrolysis. Conjugates incubated in HCl were stable in 0.5 and 1.0M HCl, but they underwent degradation in 2.0 and 4.0M HCl. Dextrans (MW 20,000) with various degrees of oxidation (12%, 26%, 46%, 65%, 90% and 93%) were also prepared. Each oxidised dextran sample was conjugated with 5-ASA, and the product was quantified by high-performance liquid chromatography (HPLC). Dextrans with a maximum degree of oxidation (93%) unsurprisingly gave maximum conjugation of 5-ASA (49.1mg per 100mg of product) but were resistant to dextranase hydrolysis. Less oxidised dextrans (12%) conjugated proportionally less 5-ASA (15.1mg per 100mg of product) but were successfully hydrolysed by dextranase, suggesting their potential applications for the treatment of Crohn's disease in the distal ileum and proximal colon.

  9. Acidic 1,3-propanediaminetetraacetato lanthanides with luminescent and catalytic ester hydrolysis properties

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Mao-Long; Shi, Yan-Ru; Yang, Yu-Chen; Zhou, Zhao-Hui, E-mail: zhzhou@xmu.edu.cn

    2014-11-15

    In acidic solution, a serials of water-soluble coordination polymers (CPs) were isolated as zonal 1D-CPs 1,3-propanediaminetetraacetato lanthanides [Ln(1,3-H{sub 3}pdta)(H{sub 2}O){sub 5}]{sub n}·2Cl{sub n}·3nH{sub 2}O [Ln=La, 1; Ce, 2; Pr, 3; Nd, 4; Sm, 5] (1,3-H{sub 4}pdta=1,3-propanediaminetetraacetic acid, C{sub 11}H{sub 18}N{sub 2}O{sub 8}) in high yields. When 1 eq. mol potassium hydroxide was added to the solutions of 1D-CPs, respectively, two 1D-CPs [Ln(1,3-H{sub 2}pdta)(H{sub 2}O){sub 3}]{sub n}·Cl{sub n}·2nH{sub 2}O [Ln=Sm, 6; Gd, 7] were isolated at room temperature and seven 2D-CPs [Ln(1,3-H{sub 2}pdta)(H{sub 2}O){sub 2}]{sub n}·Cl{sub n}·2nH{sub 2}O [Ln=La, 8; Ce, 9; Pr, 10; Nd, 11; Sm, 12; Eu, 13; Gd, 14] were isolated at 70 °C. When the crystals of 1–4 were hydrothermally heated at 180 °C with 1–2 eq. mol potassium hydroxide, four 3D-CPs [Ln(1,3-Hpdta)]{sub n}·nH{sub 2}O [Ln=La, 15; Ce, 16; Pr, 17; Nd, 18] were obtained. The two 2D-CPs [Ln(1,3-Hpdta)(H{sub 2}O)]{sub n}·4nH{sub 2}O (Sm, 19; Eu, 20) were isolated in similar reaction conditions. With the increments of pH value in the solution and reaction temperature, the structure becomes more complicated. 1–5 are soluble in water and 1 was traced by solution {sup 13}C({sup 1}H) NMR technique, the water-soluble lanthanides 1 and 5 show catalytic activity to ester hydrolysis reaction respectively, which indicate their important roles in the hydrolytic reaction. The europium complexes 13 and 20 show visible fluorescence at an excitation of 394 nm. The structure diversity is mainly caused by the variation of coordinated ligand in different pH values and lanthanide contraction effect. Acidic conditions are favorable for the isolations of lanthanide complexes in different structures and this may helpful to separate different lanthanides. The thermal stability investigations reveal that acidic condition is favorable to obtain the oxides at a lower temperature. - Graphical abstract: A series

  10. Direct lactic acid fermentation of Jerusalem artichoke tuber extract using Lactobacillus paracasei without acidic or enzymatic inulin hydrolysis.

    Science.gov (United States)

    Choi, Hwa-Young; Ryu, Hee-Kyoung; Park, Kyung-Min; Lee, Eun Gyo; Lee, Hongweon; Kim, Seon-Won; Choi, Eui-Sung

    2012-06-01

    Lactic acid fermentation of Jerusalem artichoke tuber was performed with strains of Lactobacillus paracasei without acidic or enzymatic inulin hydrolysis prior to fermentation. Some strains of L. paracasei, notably KCTC13090 and KCTC13169, could ferment hot-water extract of Jerusalem artichoke tuber more efficiently compared with other Lactobacillus spp. such as L. casei type strain KCTC3109. The L. paracasei strains could utilize almost completely the fructo-oligosaccharides present in Jerusalem artichoke. Inulin-fermenting L. paracasei strains produced c.a. six times more lactic acid compared with L. casei KCTC3109. Direct lactic fermentation of Jerusalem artichoke tuber extract at 111.6g/L of sugar content with a supplement of 5 g/L of yeast extract by L. paracasei KCTC13169 in a 5L jar fermentor produced 92.5 ce:hsp sp="0.25"/>g/L of lactic acid with 16.8 g/L fructose equivalent remained unutilized in 72 h. The conversion efficiency of inulin-type sugars to lactic acid was 98% of the theoretical yield.

  11. Structure of Human Acid Sphingomyelinase Reveals the Role of the Saposin Domain in Activating Substrate Hydrolysis.

    Science.gov (United States)

    Xiong, Zi-Jian; Huang, Jingjing; Poda, Gennady; Pomès, Régis; Privé, Gilbert G

    2016-07-31

    Acid sphingomyelinase (ASM) is a lysosomal phosphodiesterase that catalyzes the hydrolysis of sphingomyelin to produce ceramide and phosphocholine. While other lysosomal sphingolipid hydrolases require a saposin activator protein for full activity, the ASM polypeptide incorporates a built-in N-terminal saposin domain and does not require an external activator protein. Here, we report the crystal structure of human ASM and describe the organization of the three main regions of the enzyme: the N-terminal saposin domain, the proline-rich connector, and the catalytic domain. The saposin domain is tightly associated along an edge of the large, bowl-shaped catalytic domain and adopts an open form that exposes a hydrophobic concave surface approximately 30Å from the catalytic center. The calculated electrostatic potential of the enzyme is electropositive at the acidic pH of the lysosome, consistent with the strict requirement for the presence of acidic lipids in target membranes. Docking studies indicate that sphingomyelin binds with the ceramide-phosphate group positioned at the binuclear zinc center and molecular dynamic simulations indicate that the intrinsic flexibility of the saposin domain is important for monomer-dimer exchange and for membrane interactions. Overall, ASM uses a combination of electrostatic and hydrophobic interactions to cause local disruptions of target bilayers in order to bring the lipid headgroup to the catalytic center in a membrane-bound reaction.

  12. Effect of Subsequent Dilute Acid and Enzymatic Hydrolysis on Reducing Sugar Production from Sugarcane Bagasse and Spent Citronella Biomass

    Directory of Open Access Journals (Sweden)

    Robinson Timung

    2016-01-01

    Full Text Available This work was aimed at investigating the effect of process parameters on dilute acid pretreatment and enzymatic hydrolysis of spent citronella biomass (after citronella oil extraction and sugarcane bagasse on total reducing sugar (TRS yield. In acid pretreatment, the parameters studied were acid concentration, temperature, and time. At the optimized condition (0.1 M H2SO4, 120°C, and 120 min, maximum TRS obtained was 452.27 mg·g−1 and 487.50 mg·g−1 for bagasse and citronella, respectively. Enzymatic hydrolysis of the pretreated biomass using Trichoderma reesei 26291 showed maximum TRS yield of 226.99 mg·g−1 for citronella and 282.85 mg·g−1 for bagasse at 10 FPU, 50°C, and 48 hr. The maximum crystallinity index (CI of bagasse and citronella after acid pretreatment obtained from X-ray diffraction analysis was 64.41% and 56.18%, respectively. Decreased CI after enzymatic hydrolysis process to 37.28% and 34.16% for bagasse and citronella, respectively, revealed effective conversion of crystalline cellulose to glucose. SEM analysis of the untreated and treated biomass revealed significant hydrolysis of holocellulose and disruption of lignin.

  13. Enzymatic hydrolysis and fermentability of corn stover pretreated by lactic acid and/or acetic acid

    DEFF Research Database (Denmark)

    Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

    2009-01-01

    Four different pretreatments with and without addition of low concentration organic acids were carried out on corn stover at 195 °C for 15 min. The highest xylan recovery of 81.08% was obtained after pretreatment without acid catalyst and the lowest of 58.78% after pretreatment with both acetic...

  14. Cholesterol efflux from THP-1 macrophages is impaired by the fatty acid component from lipoprotein hydrolysis by lipoprotein lipase

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yanbo; Thyagarajan, Narmadaa; Coady, Breanne M.; Brown, Robert J., E-mail: rbrown@mun.ca

    2014-09-05

    Highlights: • Lipoprotein hydrolysis products were produced by lipoprotein lipase. • Hydrolysis products lowers expression of macrophage cholesterol transporters. • Hydrolysis products reduces expression of select nuclear receptors. • Fatty acid products lowers cholesterol transporters and select nuclear receptors. • Fatty acid products reduces cholesterol efflux from macrophages. - Abstract: Lipoprotein lipase (LPL) is an extracellular lipase that primarily hydrolyzes triglycerides within circulating lipoproteins. Macrophage LPL contributes to atherogenesis, but the mechanisms behind it are poorly understood. We hypothesized that the products of lipoprotein hydrolysis generated by LPL promote atherogenesis by inhibiting the cholesterol efflux ability by macrophages. To test this hypothesis, we treated human THP-1 macrophages with total lipoproteins that were hydrolyzed by LPL and we found significantly reduced transcript levels for the cholesterol transporters ATP binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor BI. These decreases were likely due to significant reductions for the nuclear receptors liver-X-receptor-α, peroxisome proliferator activated receptor (PPAR)-α, and PPAR-γ. We prepared a mixture of free fatty acids (FFA) that represented the ratios of FFA species within lipoprotein hydrolysis products, and we found that the FFA mixture also significantly reduced cholesterol transporters and nuclear receptors. Finally, we tested the efflux of cholesterol from THP-1 macrophages to apolipoprotein A-I, and we found that the treatment of THP-1 macrophages with the FFA mixture significantly attenuated cholesterol efflux. Overall, these data show that the FFA component of lipoprotein hydrolysis products generated by LPL may promote atherogenesis by inhibiting cholesterol efflux, which partially explains the pro-atherogenic role of macrophage LPL.

  15. Potential of phosphoric acid-catalyzed pretreatment and subsequent enzymatic hydrolysis for biosugar production from Gracilaria verrucosa.

    Science.gov (United States)

    Kwon, Oh-Min; Kim, Sung-Koo; Jeong, Gwi-Taek

    2016-07-01

    This study combined phosphoric acid-catalyzed pretreatment and enzymatic hydrolysis to produce biosugars from Gracilaria verrucosa as a potential renewable resource for bioenergy applications. We optimized phosphoric acid-catalyzed pretreatment conditions to 1:10 solid-to-liquid ratio, 1.5 % phosphoric acid, 140 °C, and 60 min reaction time, producing a 32.52 ± 0.06 % total reducing sugar (TRS) yield. By subsequent enzymatic hydrolysis, a 68.61 ± 0.90 % TRS yield was achieved. These results demonstrate the potential of phosphoric acid to produce biosugars for biofuel and biochemical production applications.

  16. Investigation Of The Hydrolysis Of Isocyanic Acid In Urea SCR: Catalyst Screening And Low-Temperature Kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Piazzesi, G.; Elsener, M.; Kroecher, O.; Wokaun, A.

    2005-03-01

    Several oxide catalysts were tested for the hydrolysis of isocyanic acid under typical diesel exhaust conditions. Among the tested catalysts, TiO{sub 2} and ZrO{sub 2} have been shown to be the most active catalysts. The kinetics of the HNCO hydrolysis over TiO{sub 2} at low temperatures was studied and reaction orders and the activation energy were determined. The effect of NO{sub 2} on the catalytic activity of TiO{sub 2} was also investigated, revealing that, at low temperatures, the formation of ammonium nitrate inhibits the reaction. (author)

  17. Hydrolysis of tanned leather wastes under alkaline, acidic and oxidative conditions

    Directory of Open Access Journals (Sweden)

    Botić Tatjana

    2006-01-01

    Full Text Available Different wastes in large quantities are the outcome or the by-product of processes in the tanning industry. The largest part of solid wastes is collagen based and obtained in the reprocessing steps of tanned and non-tanned products. The quality collagen substance obtained from wastes of the leather industry used as a supporting material in many reprocessing industries. Hydrolysis is the basic step of collagen processing, namely the shortening of its polypeptide chain. The main goal of this investigation was to examine the influence of the following parameters on the extent of collagen hydrolysis: type and quantity of reagent used for hydrolysis temperature of hydrolysis, pH, duration of hydrolysis as well as the dimensions of the "shavings" samples. The change of molar mass during hydrolysis was monitored by UV-spectroscopy. Special attention was paid to the dechroming process of the collagen hydrolysate.

  18. Optimization studies on acid hydrolysis of oil palm empty fruit bunch fiber for production of xylose.

    Science.gov (United States)

    Rahman, S H A; Choudhury, J P; Ahmad, A L; Kamaruddin, A H

    2007-02-01

    Oil palm empty fruit bunch fiber is a lignocellulosic waste from palm oil mills. It is a potential source of xylose which can be used as a raw material for production of xylitol, a high value product. The increasing interest on use of lignocellulosic waste for bioconversion to fuels and chemicals is justifiable as these materials are low cost, renewable and widespread sources of sugars. The objective of the present study was to determine the effect of H(2)SO(4) concentration, reaction temperature and reaction time for production of xylose. Batch reactions were carried out under various reaction temperature, reaction time and acid concentrations and Response Surface Methodology (RSM) was followed to optimize the hydrolysis process in order to obtain high xylose yield. The optimum reaction temperature, reaction time and acid concentration found were 119 degrees C, 60 min and 2%, respectively. Under these conditions xylose yield and selectivity were found to be 91.27% and 17.97 g/g, respectively.

  19. Preparation of Glycyrrhetinic Acid Monoglucuronide by Selective Hydrolysis of Glycyrrhizic Acid via Biotransformation

    Institute of Scientific and Technical Information of China (English)

    LU Li; MA Bai-ping; ZHAO Yang; YU He-shui; HUANG Hong-zhi; KANG Li-ping; CAO Man; CUI Jiang-ming; YU Li-yan; SONG Xin-bo

    2012-01-01

    Objective To search for the microorganisms which have the high selectivity of hydrolyzing glycyrrhizic acid(GL)into 18β-glycyrrhetinic acid-3-O-β-D-glucuronide(GAMG)without glycyrrhetinic acid(GA)byproduct.Methods GL was biotransformed by Aspergillus sp.,the products were separated by chromatography on reverse phase C18 column and semi-preparative HPLC,and their structures were elucidated on the basis of HR-ESI-MS,1D NMR(1H-NMR,13C-NMR,and NOESY)and 2D NMR(1H-1H COSY,HSQC,and HMBC)spectral analyses.Results Aspergillus sp.could partially hydrolyze GL into GAMG(3),along with two minor byproducts,3-O-β-D-glucurono-pyranosyl-18β-liquiritic acid(1)and 3-O-β-D-glucuronopyranosyl-24-hydroxy-18β-glycyrrhetinic acid(2).Conclusion Aspergillus sp.has the high selectivity of hydrolyzing GL into GAMG without GA byproduct and the yield of GAMG is about 60%.The complete assignments of 1H-NMR and 13C-NMR data for compounds 1 and 2 are reported for the first time.

  20. Enzymatic hydrolysis and fermentability of corn stover pretreated by lactic acid and/or acetic acid.

    Science.gov (United States)

    Xu, Jian; Thomsen, Mette Hedegaard; Thomsen, Anne Belinda

    2009-02-23

    Four different pretreatments with and without addition of low concentration organic acids were carried out on corn stover at 195 degrees C for 15 min. The highest xylan recovery of 81.08% was obtained after pretreatment without acid catalyst and the lowest of 58.78% after pretreatment with both acetic and lactic acid. Glucan recovery was less sensitive to the pretreatment conditions than xylan recovery. The pretreatment with acetic and lactic acid yielded the highest glucan recovery of 95.66%. The glucan recoveries of the other three pretreatments varied between 83.92% and 94.28%. Fermentability tests were performed on liquors obtained from all pretreatments and there were no inhibition effect found in any of the liquors. Simultaneous saccharification and fermentation (SSF) of water-insoluble solids (WIS) showed that a high ethanol yield of 88.7% of the theoretical based on glucose in the raw material was obtained following pretreatment at 195 degrees C for 15 min with acetic acid employed. The estimated total ethanol production was 241.1 kg/ton raw material by assuming fermentation of both C-6 and C-5, and 0.51 g ethanol/g sugar.

  1. Two Step Enzymatic Hydrolysis and Fermentation Strategy for Conversion of Acid Treated Hydrolysate of Corn Cob to Ethanol

    Directory of Open Access Journals (Sweden)

    *Geetanjali Swaroop Wakade

    2015-03-01

    Full Text Available For economic production of ethanol from corncobs, it is very crucial that lignocellulosic fractions containing glucose and xylose are simultaneously fermented to ethanol in a single operation i.e. cofermentation. Cofermentation of mixed acid treated corn cob hydrolysate containing mixed sugars at low concentration (<50 g L -1 using Pichia stipitis showed 92.35% ethanol fermentation efficiency. However cofermentation of corn cob hydrolysate comprising sugar above 50 g L-1 showed only 46.71% ethanol fermentation efficiency. Therefore a two step enzymatic hydrolysis and fermentation strategy was designed for cofermentation of corn cob hydrolysate containing high concentration of sugars which resulted in 86.74% enzymatic hydrolysis efficiency and 75.32% ethanol fermentation efficiency. Using two step hydrolysis and fermentation, there was 1.1 fold improvement in the enzymatic hydrolysis efficiency. Final ethanol concentration, ethanol yield and volumetric productivity were improved by 1.7, 1.66 and 2.6 fold respectively as compared to single step hydrolysis and fermentation process.

  2. Kinetic analysis of waste activated sludge hydrolysis and short-chain fatty acids production at pH 10

    Institute of Scientific and Technical Information of China (English)

    FENG Leiyu; YAN Yuanyuan; CHEN Yinguang

    2009-01-01

    The accumulation of short-chain fatty acids (SCFAs), a preferred carbon source for enhanced biological phosphorus removal microbes, was significantly improved when waste activated sludge (WAS) was fermented at pH 10. The kinetics of WAS hydrolysis and SCFAs production at pH 10 were investigated. It was observed that during WAS anaerobic fermentation at pH 10 the accumulation of SCFAs was limited by the hydrolysis process, and both the hydrolysis of WAS particulate COD and the accumulation of SCFAs followed first-order kinetics. The hydrolysis and SCFAs accumulation rate constants increased with a increasing of temperature from 10 to 35℃, which could be described by the Arrhenius equation. The kinetic data further indicated that SCFAs production at pH 10 was a biological process. Compared with the experiment of pH uncontrolled (blank test), both the rate constants of WAS hydrolysis and SCFAs accumulation at 20℃ were significantly improved when WAS was fermented at pH 10.

  3. Hexenuronic acid in South African Eucalyptus hybrid clones: optimization of the acid hydrolysis (A) stage

    CSIR Research Space (South Africa)

    Andrew, JE

    2009-10-01

    Full Text Available :tiolt tioltis (T'atr!e I). All acid trcal.mcnts wefe carricd out at a ct)nstant pll of 3.5. adiltsF cd u'ith strl.fl-rric acicl, ancl ttt 10'X, pulp consistencl. We evaluateci pulp clualitv by preparing and testing haud- sheets. Pr"rlps rvere beaten in a lil...

  4. Targeting and Imaging of Cancer Cells via Monosaccharide-Imprinted Fluorescent Nanoparticles

    Science.gov (United States)

    Wang, Shuangshou; Yin, Danyang; Wang, Wenjing; Shen, Xiaojing; Zhu, Jun-Jie; Chen, Hong-Yuan; Liu, Zhen

    2016-03-01

    The recognition of cancer cells is a key for cancer diagnosis and therapy, but the specificity highly relies on the use of biorecognition molecules particularly antibodies. Because biorecognition molecules suffer from some apparent disadvantages, such as hard to prepare and poor storage stability, novel alternatives that can overcome these disadvantages are highly important. Here we present monosaccharide-imprinted fluorescent nanoparticles (NPs) for targeting and imaging of cancer cells. The molecularly imprinted polymer (MIP) probe was fluorescein isothiocyanate (FITC) doped silica NPs with a shell imprinted with sialic acid, fucose or mannose as the template. The monosaccharide-imprinted NPs exhibited high specificity toward the target monosaccharides. As the template monosaccharides used are over-expressed on cancer cells, these monosaccharide-imprinted NPs allowed for specific targeting cancer cells over normal cells. Fluorescence imaging of human hepatoma carcinoma cells (HepG-2) over normal hepatic cells (L-02) and mammary cancer cells (MCF-7) over normal mammary epithelial cells (MCF-10A) by these NPs was demonstrated. As the imprinting approach employed herein is generally applicable and highly efficient, monosaccharide-imprinted NPs can be promising probes for targeting cancer cells.

  5. Preparation of micro-fibrillated cellulose based on sugar palm ijuk (Arenga pinnata) fibres through partial acid hydrolysis

    Science.gov (United States)

    Saputro, A.; Verawati, I.; Ramahdita, G.; Chalid, M.

    2017-07-01

    The aim of this study was to isolate and characterized micro-fibrillated cellulose (MFC) from sugar palm/ijuk fibre (Arenga pinnata) by partial sulfuric acid hydrolysis. Cellulose fibre was prepared by repeated treatments with 5 wt% sodium hydroxide 2 h at 80°C, followed by bleaching with 1.7 wt% sodium chlorite for 2 h at 80°C in acidic environment under stirring. MFC was prepared by partial hydrolysis with sulfuric acid in various concentrations (30, 40, 50, and 60 % for 45 min at 45 °C) under stirring. Fourier Transform Infrared, Field Emission Scanning Electron Microscope, Thermo Gravimetric Analyzer and X-ray Diffraction characterized cellulose fibre and MFC. FTIR measurements showed that alkaline and bleaching treatments were effective to remove non-cellulosic constituents such as wax, lignin and hemicellulose. FESEM observation revealed conversion into more clear surface and defibrillation of cellulosic fibre after pre-treatments. XRD measurement revealed increase in crystallinity after pre-treatments and acid hydrolysis from 54.4 to 87.8%. Thermal analysis showed that increasing acid concentration reduced thermal stability.

  6. Selection of suitable mineral acid and its concentration for biphasic dilute acid hydrolysis of the sodium dithionite delignified Prosopis juliflora to hydrolyze maximum holocellulose.

    Science.gov (United States)

    Naseeruddin, Shaik; Desai, Suseelendra; Venkateswar Rao, L

    2016-02-01

    Two grams of delignified substrate at 10% (w/v) level was subjected to biphasic dilute acid hydrolysis using phosphoric acid, hydrochloric acid and sulfuric acid separately at 110 °C for 10 min in phase-I and 121 °C for 15 min in phase-II. Combinations of acid concentrations in two phases were varied for maximum holocellulose hydrolysis with release of fewer inhibitors, to select the suitable acid and its concentration. Among three acids, sulfuric acid in combination of 1 & 2% (v/v) hydrolyzed maximum holocellulose of 25.44±0.44% releasing 0.51±0.02 g/L of phenolics and 0.12±0.002 g/L of furans, respectively. Further, hydrolysis of delignified substrate using selected acid by varying reaction time and temperature hydrolyzed 55.58±1.78% of holocellulose releasing 2.11±0.07 g/L and 1.37±0.03 g/L of phenolics and furans, respectively at conditions of 110 °C for 45 min in phase-I & 121 °C for 60 min in phase-II.

  7. Hydrolysis of solubilized hemicellulose derived from wet-oxidized wheat straw by a mixture of commercial fungal enzyme preparations

    Energy Technology Data Exchange (ETDEWEB)

    Skammelsen Schmidt, Anette; Thomsen, Alle Belinda; Woidemann, Anders [Risoe National Lab. (Denmark); Tenkanen, Maija [VTT Biotechnology and Food Research (Finland)

    1998-04-01

    The enzymatic hydrolysis of the solubilized hemicellulose fraction from wet-oxidized wheat straw was investigated for quantification purposes. An optimal hydrolysis depends on factors such as composition of the applied enzyme mixture and the hydrolysis conditions (enzyme loading, hydrolysis time, pH-value, and temperature). A concentrated enzyme mixture was used in this study prepared at VTT Biotechnology and Food Research, Finland, by mixing four commercial enzyme preparations. No distinctive pH-value and temperature optima were identified after a prolonged incubation of 24 hours. By reducing the hydrolysis time to 2 hours a temperature optimum was found at 50 deg. C, where a pH-value higher than 5.2 resulted in reduced activity. An enzyme-substrate-volume-ratio of 0.042, a pH-value of 5.0, and a temperature of 50 deg. C were chosen as the best hydrolysis conditions due to an improved monosaccharide yield. The hydrolysis time was chosen to be 24 hours to ensure equilibrium and total quantification. Even under the best hydrolysis conditions, the overall sugar yield from the enzymatic hydrolysis was only 85% of that of the optimal acid hydrolysis. The glucose yield were approximately the same for the two types of hydrolyses, probably due to the high cellulase activity in the VTT-enzyme mixture. For xylose and arabinose the enzymatic hydrolysis yielded only 80% of that of the acid hydrolysis. As the pentoses existed mainly as complex polymers their degradation required many different enzymes, some of which might be missing from the VTT-enzyme mixture. Furthermore, the removal of side-choins from the xylan backbone during the wet-oxidation pretreatment process might enable the hemicellulosic polymers to interact and precipitate, hence, reducing the enzymatic digestibility of the hemicellulose. (au) 8 tabs., 10 ills., 65 refs.

  8. Structural investigation of a uronic acid-containing polysaccharide from abalone by graded acid hydrolysis followed by PMP-HPLC-MSn and NMR analysis.

    Science.gov (United States)

    Wang, Hong-xu; Zhao, Jun; Li, Dong-mei; Song, Shuang; Song, Liang; Fu, Ying-huan; Zhang, Li-peng

    2015-01-30

    A new strategy was applied to elucidate the structure of a polysaccharide from abalone gonad (AGSP). It was hydrolyzed by 0.05 M, 0.2 M, 0.5 M, and 2.0 M TFA at 100 °C for 1 h, sequentially. Every hydrolysate was ultrafiltrated (3000 Da) to collect oligo- and monosaccharides, and the final retentate was further hydrolyzed with 2.0 M TFA at 110 °C and 121 °C for 2 h, respectively. 1-Phenyl-3-methyl-5-pyrazolone (PMP) derivatization followed by HPLC-MSn analysis was applied to detect the sugar residues in these hydrolysates, which allowed proposing their location in the polysaccharide structure. The retentate after 0.5 M TFA hydrolysis was confirmed as the polysaccharide backbone, and it was further analyzed by 1D and 2D NMR spectroscopy. Thus, the structural elucidation of AGSP was accomplished, and it has a backbone of →4)-β-GlcA(1→2)-α-Man(1→ repeating unit with Fuc, Xyl and Gal in the branch. The analytical strategy demonstrated was useful to characterize the structure of polysaccharides.

  9. Synthesis and enzymic hydrolysis of cyclic peptides containing an anthranilic acid residue.

    Science.gov (United States)

    Mazaleyrat, J P; Reboud-Ravaux, M; Wakselman, M

    1987-11-01

    Two cyclic peptides cyclo (Phe-MeAnt-Glyn) with MeAnt = 5-methyl-anthranilic acid residue, n = 4 (3b) and n = 6 (4b), have been synthesized in solution and their reaction with alpha-chymotrypsin analyzed. The polyglycyl chain was prepared by the phosphazo method; cyclization at the Gly-Phe site occurred in good yield using the azide method. Catalysis of the hydrolysis of peptides 3b and 4b by alpha-chymotrypsin was characterized at 37 degrees by the apparent second-order rate constants kcat/Km 0.12 and 1.15 M-1 S-1, respectively, in agreement with the usual acceleration observed upon enlargement of the size of the peptidic ring in cyclic peptides. alpha-Chymotrypsin specifically split the Phe-MeAnt amide bond in cyclopeptide 4b. This specific orientation suggests that analogous structures with a functionalized methylene group instead of the methyl substituent can be used in the design of suicide substrates for serine proteases.

  10. Valorisation of food waste via fungal hydrolysis and lactic acid fermentation with Lactobacillus casei Shirota.

    Science.gov (United States)

    Kwan, Tsz Him; Hu, Yunzi; Lin, Carol Sze Ki

    2016-10-01

    Food waste recycling via fungal hydrolysis and lactic acid (LA) fermentation has been investigated. Hydrolysates derived from mixed food waste and bakery waste were rich in glucose (80.0-100.2gL(-1)), fructose (7.6gL(-1)) and free amino nitrogen (947-1081mgL(-1)). In the fermentation with Lactobacillus casei Shirota, 94.0gL(-1) and 82.6gL(-1) of LA were produced with productivity of 2.61gL(-1)h(-1) and 2.50gL(-1)h(-1) for mixed food waste and bakery waste hydrolysate, respectively. The yield was 0.94gg(-1) for both hydrolysates. Similar results were obtained using food waste powder hydrolysate, in which 90.1gL(-1) of LA was produced with a yield and productivity of 0.92gg(-1) and 2.50gL(-1)h(-1). The results demonstrate the feasibility of an efficient bioconversion of food waste to LA and a decentralized approach of food waste recycling in urban area. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Sequential acid and enzymatic hydrolysis in situ and bioethanol production from Gracilaria biomass.

    Science.gov (United States)

    Wu, Fang-Chen; Wu, Jane-Yii; Liao, Yi-Jyun; Wang, Man-Ying; Shih, Ing-Lung

    2014-03-01

    Gracilaria sp., a red alga, was used as a feedstock for the production of bioethanol. Saccharification of Gracilaria sp. by sequential acid and enzyme hydrolysis in situ produced a high quality hydrolysate that ensured its fermentability to produce ethanol. The optimal saccharification process resulted in total 11.85g/L (59.26%) of glucose and galactose, Saccharomyces cerevisiae Wu-Y2 showed a good performance on co-fermentability of glucose and galactose released in the hydrolysate from Gracilaria sp. The final ethanol concentrations of 4.72g/L (0.48g/g sugar consumed; 94% conversion efficiency) and the ethanol productivity 4.93g/L/d were achieved. 1g of dry Gracilaria can be converted to 0.236g (23.6%) of bioethanol via the processes developed. Efficient alcohol production by immobilized S. cerevisiae Wu-Y2 in batch and repeated batch fermentation was also demonstrated. The findings of this study revealed that Gracilaria sp. can be a potential feedstock in biorefinery for ethanol production.

  12. Biopolymer from microbial assisted in situ hydrolysis of triglycerides and dimerization of fatty acids.

    Science.gov (United States)

    Kavitha, V; Radhakrishnan, N; Madhavacharyulu, E; Sailakshmi, G; Sekaran, G; Reddy, B S R; Rajkumar, G Suseela; Gnanamani, Arumugam

    2010-01-01

    The present study demonstrates biopolymer production by in situ bio-based dimerization of fatty acids by microorganism isolated from marine sediments. Microbial isolate grown in Zobell medium in the presence of triglycerides for the period of 24-240 h at 37 degrees C, hydrolyze the applied triglycerides and sequentially dimerized the hydrolyzed products and subsequently polymerized and transformed to a biopolymer having appreciable adhesive properties. Physical (nature, odour, stickyness and tensile strength), chemical (instrumentation) and biochemical (cell free broth) methods of analyses carried out provided the hypotheses involved in the formation of the product as well as the nature of the product formed. Results revealed, lipolytic enzymes released during initial period of growth and the biosurfactant production during later period, respectively, hydrolyze the applied triglycerides and initiate the dimerization and further accelerated when the incubation period extended. The existence and the non-existence of in situ hydrolysis of various triglycerides followed by dimerization and polymerization and the mechanism of transformation of triglycerides to biopolymer are discussed in detail.

  13. Steam gasification of acid-hydrolysis biomass CAHR for clean syngas production.

    Science.gov (United States)

    Chen, Guanyi; Yao, Jingang; Yang, Huijun; Yan, Beibei; Chen, Hong

    2015-03-01

    Main characteristics of gaseous product from steam gasification of acid-hydrolysis biomass CAHR have been investigated experimentally. The comparison in terms of evolution of syngas flow rate, syngas quality and apparent thermal efficiency was made between steam gasification and pyrolysis in the lab-scale apparatus. The aim of this study was to determine the effects of temperature and steam to CAHR ratio on gas quality, syngas yield and energy conversion. The results showed that syngas and energy yield were better with gasification compared to pyrolysis under identical thermal conditions. Both high gasification temperature and introduction of proper steam led to higher gas quality, higher syngas yield and higher energy conversion efficiency. However, excessive steam reduced hydrogen yield and energy conversion efficiency. The optimal value of S/B was found to be 3.3. The maximum value of energy ratio was 0.855 at 800°C with the optimal S/B value. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Acidic hydrolysis of bromazepam studied by high performance liquid chromatography. Isolation and identification of its degradation products.

    Science.gov (United States)

    Panderi, I; Archontaki, H; Gikas, E; Parissi-Poulou, M

    1998-06-01

    A kinetic study on the acidic hydrolysis of bromazepam was carried out in 0.01 M hydrochloric acid solution at 25 and 95 degrees C. A reversed-phase HPLC method was developed and validated for the determination of bromazepam and its degradation products. Bromazepam degraded by a consecutive reaction with a reversible first step. Two degradation products were isolated and identified by infrared, 1H and 13C nuclear magnetic resonance and mass spectroscopy. Spectroscopic data indicated that N-(4-bromo-2-(2-pyridylcarbonyl)phenyl)-2-aminoacetamide was the intermediate degradation product of this acid hydrolysis, whereas 2-amino-5-bromophenyl-2-pyridylmethanone was the final one. Therefore, the mechanism of this acid-catalysed hydrolysis involved initial cleavage of the 4,5-azomethine bond, followed by slow breakage of the 1,2-amide bond. Statistical evaluation of the HPLC method revealed its good linearity and reproducibility. Detection limits were 3.8 x 10(-7) M for bromazepam, 6.25 x 10(-7) M for the intermediate and 8.16 x 10(-7) M for the benzophenone derivative.

  15. Optimization of Brewery's spent grain dilute-acid hydrolysis for the production of pentose-rich culture media.

    Science.gov (United States)

    Carvalheiro, Florbela; Duarte, Luís C; Medeiros, Raquel; Gírio, Francisco M

    2004-01-01

    Dilute-acid hydrolysis of brewery's spent grain to obtain a pentose-rich fermentable hydrolysate was investigated. The influence of operational conditions on polysaccharide hydrolysis was assessed by the combined severity parameter (CS) in the range of 1.39-3.06. When the CS increased, the pentose sugars concentration increased to a maximum at a CS of 1.94, whereas the maximum glucose concentration was obtained for a CS of 2.65. The concentrations of furfural, hydroxymethylfurfural (HMF), as well as formic and levulinic acids and total phenolic compounds increased with severity. Optimum hydrolysis conditions were found at a CS of 1.94 with >95% of feedstock pentose sugars recovered in the monomeric form, together with a low content of furfural, HMF, acetic and formic acids, and total phenolic compounds. This hydrolysate containing glucose, xylose, and arabinose (ratio 10:67:32) was further supplemented with inorganic salts and vitamins and readily fermented by the yeast Debaryomyces hansenii CCMI 941 without any previous detoxification stage. The yeast was able to consume all sugars, furfural, HMF, and acetic acid with high biomass yield, 0.68 C-mol/C-mol, and productivity, 0.92 g/(L.h). Detoxification with activated charcoal resulted in a similar biomass yield and a slight increase in the volumetric productivity (11%).

  16. The effect of pH on hydrolysis, cross-linking and barrier properties of starch barriers containing citric acid.

    Science.gov (United States)

    Olsson, Erik; Menzel, Carolin; Johansson, Caisa; Andersson, Roger; Koch, Kristine; Järnström, Lars

    2013-11-01

    Citric acid cross-linking of starch for e.g. food packaging applications has been intensely studied during the last decade as a method of producing water-insensitive renewable barrier coatings. We managed to improve a starch formulation containing citric acid as cross-linking agent for industrial paper coating applications by adjusting the pH of the starch solution. The described starch formulations exhibited both cross-linking of starch by citric acid as well as satisfactory barrier properties, e.g. fairly low OTR values at 50% RH that are comparable with EVOH. Furthermore, it has been shown that barrier properties of coated papers with different solution pH were correlated to molecular changes in starch showing both hydrolysis and cross-linking of starch molecules in the presence of citric acid. Hydrolysis was shown to be almost completely hindered at solution pH≥4 at curing temperatures≤105 °C and at pH≥5 at curing temperatures≤150 °C, whereas cross-linking still occurred to some extent at pH≤6.5 and drying temperatures as low as 70 °C. Coated papers showed a minimum in water vapor transmission rate at pH 4 of the starch coating solution, corresponding to the point where hydrolysis was effectively hindered but where a significant degree of cross-linking still occurred.

  17. Microbiological titration of proteins and of single amino acid content in biological materials without purification and hydrolysis.

    Science.gov (United States)

    Puppo, S; Morpurgo, G; Nardi, S; Conti, G

    1978-04-01

    A method is described for the microbiological determination of the protein content of biological materials. This method can also be adopted to titrate the concentration of a single amino acid in the protein and has the following advantages: (1) titration can be done without purification and hydrolysis of proteins; (2) the titration graph is a straight line between 25 and 800 microgram/ml; (3) protein values agree with those obtained using the Kjeldhal method; and (4) each mutant requiring one amino acid may be used to titrate the concentration of a single amino acid of the protein. The leucine content of various kinds of flour was measured with this system.

  18. Monosaccharides in health and disease.

    Science.gov (United States)

    Levine, R

    1986-01-01

    In healthy persons, glucose homeostasis maintains blood glucose levels between 70 and 130 mg/dl despite perturbations by meals, fasting, and exercise. Long-term follow-up of diabetic patients has suggested that "good control" of blood sugar levels minimizes the long-term complications of diabetes, such as retinopathy, nephropathy, and atherosclerosis. It now seems likely the products of insulin-independent metabolic pathways in epithelial and endothelial cells leading to polyol formation and protein glycosylation may be factors in the genesis of retinopathy, neuropathy, nephropathy, and premature atherosclerosis of diabetic patients. Dietary complex carbohydrates of various type, including those rich in dietary fiber, which are the cell walls of fruits, vegetables, and cereals, may slow the rate of absorption of glucose from those diets and contribute to a lowering of the postprandial glucose peak. Glycemic responses to various foods compared to glucose have been studied and show a large variation, which is dependent upon gastric emptying, overall effects on rate of hydrolysis and absorption of glucose from food mixtures. Dietary sucrose seems to cause a degree of insulin resistance. The active part of the disaccharide is fructose, which does not elicit an acute insulin response, but appears indirectly to increase insulin levels in both animals and man. Sucrose in animals appears to promote obesity more than glucose because of its lack of stimulation of thermogenesis. Xylitol has been used as a sweetener and as a sugar substitute in total parenteral nutrition. It is a paradox that the most physiological of sugars (glucose) can be a menace at high concentrations. The use of nonphysiological sugars or their derivatives in diabetics and patients with special needs, such as TPN, requires much more investigation to develop a sound rationale in nutrition management.

  19. Effects of waste activated sludge and surfactant addition on primary sludge hydrolysis and short-chain fatty acids accumulation.

    Science.gov (United States)

    Ji, Zhouying; Chen, Guanlan; Chen, Yinguang

    2010-05-01

    This paper focused on the effects of waste activated sludge (WAS) and surfactant sodium dodecylbenzene sulfonate (SDBS) addition on primary sludge (PS) hydrolysis and short-chain fatty acids (SCFA) accumulation in fermentation. The results showed that sludge hydrolysis, SCFA accumulation, NH(4)(+)-N and PO(4)(3-)-P release, and volatile suspended solids (VSS) reduction were increased by WAS addition to PS, which were further increased by the addition of SDBS to the mixture of PS and WAS. Acetic, propionic and valeric acids were the top three SCFA in all experiments. Also, the fermentation liquids of PS, PS+WAS, and PS+WAS+SDBS were added, respectively, to municipal wastewater to examine their effects on biological municipal wastewater treatment, and the enhancement of both wastewater nitrogen and phosphorus removals was observed compared with no fermentation liquid addition.

  20. Structural features of dilute acid, steam exploded, and alkali pretreated mustard stalk and their impact on enzymatic hydrolysis.

    Science.gov (United States)

    Kapoor, Manali; Raj, Tirath; Vijayaraj, M; Chopra, Anju; Gupta, Ravi P; Tuli, Deepak K; Kumar, Ravindra

    2015-06-25

    To overcome the recalcitrant nature of biomass several pretreatment methodologies have been explored to make it amenable to enzymatic hydrolysis. These methodologies alter cell wall structure primarily by removing/altering hemicelluloses and lignin. In this work, alkali, dilute acid, steam explosion pretreatment are systematically studied for mustard stalk. To assess the structural variability after pretreatment, chemical analysis, surface area, crystallinity index, accessibility of cellulose, FT-IR and thermal analysis are conducted. Although the extent of enzymatic hydrolysis varies upon the methodologies used, nevertheless, cellulose conversion increases from pretreatment. Glucose yield at 2 and 72h are well correlated with surface area and maximum adsorption capacity. However, no such relationship is observed for xylose yield. Mass balance of the process is also studied. Dilute acid pretreatment is the best methodology in terms of maximum sugar yield at lower enzyme loading.

  1. Cellulase Inhibition by High Concentrations of Monosaccharides

    DEFF Research Database (Denmark)

    Hsieh, Chia-Wen; Cannella, David; Jørgensen, Henning

    2014-01-01

    that low free water availability contributes to cellulase inhibition. Of the hydrolytic enzymes involved, those acting on the cellulose substrate, that is, exo- and endoglucanases, were the most inhibited. The β -glucosidases were shown to be less sensitive to high monosaccharide concentrations except...

  2. Heat integration of an ethanol polygeneration plant based on lignocellulose: Comparing weak acid hydrolysis and enzymatic hydrolysis; Energiintegrerat etanolkombinat baserat paa lignocellulosa - Jaemfoerelse mellan svagsyrahydrolys och enzymhydrolys

    Energy Technology Data Exchange (ETDEWEB)

    Olsson, Marcus; Nordman, Roger; Taherzadeh, Mohammad

    2011-07-01

    Plants for bioethanol production have been planned in several cities in Sweden, including Boraas. This report provides answers to general questions regarding how such a facility's energy demand is affected by the external integration with a heat and power plant and the internal energy integration between process units. Heat integration of a bioethanol plant means that energy is reused as much as is technically possible; this sets a practical minimum level for the energy demand of the plant. In the study, ethanol production from cellulose has been simulated using Aspen Plus. Weak acid hydrolysis and enzymatic hydrolysis have been simulated, each with 50,000 and 100,000 tonnes of ethanol per year, resulting in four simulation cases. In all cases, heat integration is evaluated using pinch analysis. The steam in the ethanol plant has been covered by steam from a heat and power plant similar to that found today in Boraas. It is important to note that the energy quotas reported here includes energy use for upgrading the residual products. This leads to lower energy quotas than would be the case if the upgrading of residuals were allocated outside of the ethanol production. The conclusions from the project are: - The steam demand of the ethanol plant leads to a reduction in both the electricity and heat production of the heat and power plant. For the weak acid hydrolysis, the electricity loss is relatively high, 26-98%, which will affect the revenue significantly. The loss of electricity production is lower for the enzymatic process: 11-47%. - The difference in decreased electricity between the theoretical case of heating the raw material and the two alternative heating cases is about a factor of two, so the design of the heating of raw material is extremely important. - The reduced heat output of the power plant can, in most cases, be balanced by the surplus heat from the ethanol plant, but to completely balance the shortage, heat over 100 deg C must be used

  3. The Acid Hydrolysis Mechanism of Acetals Catalyzed by a Supramolecular Assembly in Basic Solution

    Energy Technology Data Exchange (ETDEWEB)

    Pluth, Michael D.; Bergman, Robert G.; Raymond, Kenneth N.

    2008-09-24

    A self-assembled supramolecular host catalyzes the hydrolysis of acetals in basic aqueous solution. The mechanism of hydrolysis is consistent with the Michaelis-Menten kinetic model. Further investigation of the rate limiting step of the reaction revealed a negative entropy of activation ({Delta}S{double_dagger} = -9 cal mol{sup -1}K{sup -1}) and an inverse solvent isotope effect (k(H{sub 2}O)/k(D{sub 2}O) = 0.62). These data suggest that the mechanism of hydrolysis that takes place inside the assembly proceeds through an A-2 mechanism, in contrast to the A-1 mechanism operating in the uncatalyzed reaction. Comparison of the rates of acetal hydrolysis in the assembly with the rate of the reaction of unencapsulated substrates reveals rate accelerations of up to 980 over the background reaction for the substrate diethoxymethane.

  4. Quick characterization of uronic acid-containing polysaccharides in 5 shellfishes by oligosaccharide analysis upon acid hydrolysis.

    Science.gov (United States)

    Liu, Bin; Lu, Jiaojiao; Ai, Chunqing; Zhang, Bao; Guo, Li; Song, Shuang; Zhu, Beiwei

    2016-11-29

    Uronic acid-containing polysaccharides (UACPs) including well-known glycosaminoglycans (GAGs) and some non-GAGs exist widely in animal kingdom. Although numerous methods have been established to analyze GAGs, few methods are available for non-GAG UACPs. In the present study, a protocol to identify all kinds of UACPs with repeating disaccharide units of hexosamine and uronic acid was demonstrated, and UACP components in five shellfishes, namely Turritella fortilirata Sowerby (GTF), Batillaria zonalis (GBZ), Nassarius variciferus (GNV), Monodonta labio Linnaeus (GML), and Argopecten irradians Lamarck (BAI) were primarily revealed. After a simple isolation procedure, crude polysaccharides were depolymerized by controlled acid hydrolysis, and then the resulting oligosaccharides were detected by HPLC coupled with mass spectrometer after 1-phenyl-3-methyl-5-pyrazolone (PMP) labeling. According to chromatograms using the triple quadrupole mass spectrometer in the multiple reaction monitoring (MRM) mode, chondroitin sulfate (CS) was found in GNV and GML, a non-GAG named abalone gonad sulfated polysaccharide (AGSP) with a backbone of →4)-β-GlcA-(1 → 2)-α-Man-(1→ repeating units in GBZ, and both of AGSP and CS in BAI and GTF. Further characterization of tetrasaccharides and sulfated/acetylated disaccharides by HPLC combined with an ion trap mass spectrometer confirmed the structural identification of CS and AGSP, and indicated CS in GTF and BAI was Type C. These results suggest the 5 mollusks as potential resources for CS and AGSP. And the analysis protocol presented in this study was powerful and effective for quick characterization of UACPs including GAGs as well as non-GAGs in complicated matrix.

  5. Determination of DNA adducts by combining acid-catalyzed hydrolysis and chromatographic analysis of the carcinogen-modified nucleobases.

    Science.gov (United States)

    Leung, Elvis M K; Deng, Kailin; Wong, Tin-Yan; Chan, Wan

    2016-01-01

    The commonly used method of analyzing carcinogen-induced DNA adducts involves the hydrolysis of carcinogen-modified DNA samples by using a mixture of enzymes, followed by (32)P-postlabeling or liquid chromatography (LC)-based analyses of carcinogen-modified mononucleotides/nucleosides. In the present study, we report the development and application of a new approach to DNA adduct analysis by combining the H(+)/heat-catalyzed release of carcinogen-modified nucleobases and the use of LC-based methods to analyze DNA adducts. Results showed that heating the carcinogen-modified DNA samples at 70 °C for an extended period of 4 to 6 h in the presence of 0.05% HCl can efficiently induce DNA depurination, releasing the intact carcinogen-modified nucleobases for LC analyses. After optimizing the hydrolysis conditions, DNA samples with C8- and N (2) -modified 2'-deoxyguanosine, as well as N (6) -modified 2'-deoxyadenosine, were synthesized by reacting DNA with 1-nitropyrene, acetaldehyde, and aristolochic acids, respectively. These samples were then hydrolyzed, and the released nucleobase adducts were analyzed using LC-based analytical methods. Analysis results demonstrated a dose-dependent release of target DNA adducts from carcinogen-modified DNA samples, indicating that the developed H(+)/heat-catalyzed hydrolysis method was quantitative. Comparative studies with enzymatic digestion method on carcinogen-modified DNA samples revealed that the two hydrolysis methods did not yield systematically different results.

  6. Sulfuric acid hydrolysis and detoxification of red alga Pterocladiella capillacea for bioethanol fermentation with thermotolerant yeast Kluyveromyces marxianus.

    Science.gov (United States)

    Wu, Chien-Hui; Chien, Wei-Chen; Chou, Han-Kai; Yang, Jungwoo; Lin, Hong-Ting Victor

    2014-09-01

    One-step sulfuric acid saccharification of the red alga Pterocladiella capillacea was optimized, and various detoxification methods (neutralization, overliming, and electrodialysis) of the acid hydrolysate were evaluated for fermentation with the thermotolerant yeast Kluyveromyces marxianus. A proximate composition analysis indicated that P. capillacea was rich in carbohydrates. A significant galactose recovery of 81.1 ± 5% was also achieved under the conditions of a 12% (w/v) biomass load, 5% (v/v) sulfuric acid, 121°C, and hydrolysis for 30 min. Among the various detoxification methods, electrodialysis was identified as the most suitable for fermentable sugar recovery and organic acid removal (100% reduction of formic and levulinic acids), even though it failed to reduce the amount of the inhibitor 5-HMF. As a result, K. marxianus fermentation with the electrodialyzed acid hydrolysate of P. capillacea resulted in the best ethanol levels and fermentation efficiency.

  7. Evaluation of photolysis and hydrolysis of atrazine and its first degradation products in the presence of humic acids

    Energy Technology Data Exchange (ETDEWEB)

    Prosen, Helena [University of Ljubljana, Faculty of Chemistry and Chemical Technology, Askerceva 5, SI-1000 Ljubljana (Slovenia)]. E-mail: helena.prosen@uni-lj.si; Zupancic-Kralj, Lucija [University of Ljubljana, Faculty of Chemistry and Chemical Technology, Askerceva 5, SI-1000 Ljubljana (Slovenia)

    2005-02-01

    Relative importance of hydrolysis and photolysis of atrazine and its degradation products in aqueous solutions with dissolved humic acids (HA) has been assessed under exposure to sunlight and under UV irradiation. Quantum yield for direct photolysis of atrazine at 254 nm was 0.037 mol photon{sup -1}, the reaction order was 0.8. Atrazine, desethylatrazine and desisopropylatrazine converted to their 2-hydroxy analogs with rate constants 0.02-0.08 min{sup -1} in clear solutions, while addition of HA (300 mg L{sup -1}) caused a 10-fold increase in rate constants. Hydroxyatrazine was not degraded. No evidence of photo-Fenton reaction was found. Under exposure to solar light, atrazine, desethylatrazine and desisopropylatrazine were converted to 2-hydroxy analogs only at pH 2 because of acid hydrolysis and possible contribution of photolysis. At lower HA concentration, only their light-shielding effect was noticed, while at higher concentrations, HA-catalysed hydrolysis prevailed. Hydroxyatrazine concentration diminished at all pH values in solutions without HA exposed to sunlight. - Different humic acid-influenced degradation processes influence atrazine and its degradation products.

  8. Pretreatment by extremely low acid hydrolysis combed with enzymolysis improving saccharification efficiency of corn stalk%超低酸预处理结合酶解提高玉米秸秆糖化效率

    Institute of Scientific and Technical Information of China (English)

    曹焱鑫; 邵丽杰; 张欢; 寇巍; 王晓明; 张大雷

    2014-01-01

    Corn straw is one of the most abundant agricultural and forest residues containing cellulose, hemicellulose, and lignin. About 2.24×108 tons of corn straw are produced per year in china, most of which is burned or lost in farmland, and only a small part is used as feed for livestock. Because corn straw is abundant in cellulose, it can be used as a substitute for grain to produce fuel-ethanol, which can be a significant contribution for relieving the crisis of resource and foodstuff shortage. The process of producing fuel-ethanol includes pretreatment, enzymatic hydrolysis, fermentation, and distillation. Cellulose, hemicellulose, and lignin in corn straw form stable polymers, which hardly dissolve in water, dilute acid, dilute alkali, and most organic solutions. Each component interrelates with all the others. Because of the complex configuration, hemicellulose and lignin will hinder the degradation of cellulose. To utilize the cellulose, corn straw must be pretreated. To improve the reduction of sugar yield in corn straw, the hydrolysis method of using extremely low sulfuric acid followed by enzymolysis is employed to treat corn stalk. To investigate the mechanism of reducing sugar conversion in acid hydrolysis and enzymolysis, the yield of totally reduced sugar, glucose and xylose was analyzed with acid hydrolysis followed by enzymolysis under different acid concentrations, temperatures and reaction times. Acid concentrations 0.1%, 160℃, 55 min, 180 r/min, solid-liquid ratio 1:10 was confirmed by orthogonal experiment. Through acid hydrolysis followed by enzymolysis (enzyme 5.0%, pH 4.6, 24 h, 50℃), the yield of totally reduced sugar, glucose, and xylose was 56.22%, 16.97%and 18.83%, respectively. The concentration of totally reduced sugar, glucose, and xylose was 62.46, 18.85 and 20.92 g/L, respectively. After acid hydrolysis and enzymolysis treatment, the corn stalk component was analyzed by infrared spectral and the Van Soest methods. The conversion of

  9. Characteristics of Bone Gelatin Tilapia (Oreochromis niloticus Processed by Using Hydrolysis With Phosphoric Acid and Papain Enzyme

    Directory of Open Access Journals (Sweden)

    Gugun Hidayat

    2016-04-01

    Full Text Available Phosphoric acid and papain enzyme able to hydrolyzing collagen from Tilapia into gelatin . Thepurpose of this research was to determine the best concentration of phosphoric acid and papain enzymeand to determine the physicochemical characteristic gelatin to from Tilapia fish bone which processedwith phosphoric acid and papain enzyme. The first research phase was making bone gelatin tilapia usingphosphoric acid at concentration of 4%, 5% and 6%, and the papain enzyme 0.5%, 1% and 1.5%. Thesecond phase was characterize the physicochemical gelatin from the best concentration of phosphoric acidconcentration (6% and papain enzyme (1.5%, all treatment done with three repetitions. Analysis of thedata using ANOVA with completely randomized (CRD design If there was difference between treatmentthen continued with Honestly Significant Difference Test (HSDT. The results of the first research phasefound the best concentration were 6% of phosphoric acid and 1.5% papain enzyme, its shows by the valuegel strength 325,95 and 373,32 g.bloom. The second research phase shows that the the best results obtainedin this study was gelatin from 1.5% papain enzyme as hydrolysis agent, the physicochemical characteristicwere: 376.21 g.bloom gel strength; viscosity of 7.57 cP; yield 6.30%; protein content of 86.46%; water contentof 7.12%; and the pH value of 5.11.Keywords : gelatin, hydrolysis, papain enzyme, phosphoric acid, tilapia bones

  10. ESTIMATION OF HYDROLYSIS RATE CONSTANTS OF CARBOXYLIC ACID ESTER AND PHOSPHATE ESTER COMPOUNDS IN AQUEOUS SYSTEMS FROM MOLECULAR STRUCTURE BY SPARC

    Science.gov (United States)

    SPARC (SPARC Performs Automated Reasoning in Chemistry) chemical reactivity models were extended to calculate hydrolysis rate constants for carboxylic acid ester and phosphate ester compounds in aqueous non- aqueous and systems strictly from molecular structure. The energy diffe...

  11. Kinetics and mechanism of S-nitrosothiol acid-catalyzed hydrolysis: sulfur activation promotes facile NO+ release.

    Science.gov (United States)

    Moran, Ernesto E; Timerghazin, Qadir K; Kwong, Elizabeth; English, Ann M

    2011-03-31

    The denitrosation of three primary S-nitrosothiols (RSNO; S-nitrosocysteine, S-nitroso-N-acetylcysteine, and S-nitrosoglutathione) and two tertiary RSNOs (S-nitrosopenicillamine and S-nitroso-N-acetylpenicillamine) was investigated in 3.75 M H(2)SO(4) to probe the mechanism of acid-catalyzed RSNO hydrolysis and its dependence on RSNO structure. This reversible reaction was forced to proceed in the denitrosation direction by trapping the nitrosating agent with HN(3). The primary RSNOs exhibited hydrolysis k(obs) values of ∼2 × 10(-4) s(-1), and the tertiary RSNO k(obs) values were an order of magnitude higher. Product analysis by HPLC revealed that the parent thiols (RSHs) were formed in 90-100% yield on 79-99% RSNO denitrosation. Possible hydrolysis mechanisms were studied computationally at the CBS-QB3 level using S-nitrosomethanethiol (MeSNO) as a model RSNO. Consideration of RSNOs as a combination of conventional R-S-N═O, zwitterionic R-S(+)═N-O(-), and RS(-)/NO(+) ion-pair resonance structures was key in understanding the mechanistic details of acid-catalyzed hydrolysis. Protonation of the S-nitroso oxygen or nitrogen activates the sulfur and nucleophilic attack by H(2)O at this atom leads to the formation of the sulfoxide-protonated N-hydroxysulfinamide, MeS(+)(OH)NHOH, with barriers of 19 and 29 kcal/mol, respectively. Proton loss and reprotonation at the nitrogen lead to secondary hydrolysis that produces the sulfinic acid MeS(═O)OH and NH(2)OH. Notably, no low-energy RSNO hydrolysis pathway for HNO release was found in the computational analysis. Protonation of the S-nitroso sulfur gives rise to NO(+) release with a low activation barrier (ΔH(double dagger)(calc) ≈ 6 kcal/mol) and the formation of MeSH in agreement with experiment. The experimental k(obs) can be expressed as K(a)k(1), where K(a) is the acid dissociation constant for protonation of the S-nitroso sulfur and k(1) the pseudo-first-order hydrolysis rate constant. Given the low

  12. Hydrolysis mechanism of anticancer drug lobaplatin in aqueous medium under neutral and acidic conditions: A DFT study

    Science.gov (United States)

    Reddy B., Venkata P.; Mukherjee, Subhajit; Mitra, Ishani; Mahata, Sujay; Linert, Wolfgang; Moi, Sankar Ch.

    2016-10-01

    We have studied the hydrolysis mechanism of lobaplatin in aqueous medium under neutral and acidic conditions using density functional theory combining with CPCM model. The stationary states located on potential energy surface were fully optimized and characterised. The rate limiting step in neutral conditions, ring opening reaction with an activation energy of 110.21 kJ mol-1. The completely hydrolysed complex is expected to be the reactive species towards the DNA purine bases. In acidic conditions, ligand detachment is the rate limiting step with an activation energy of 113.82 kJ mol-1. Consequently, monohydrated complex is expected to be the species reacting with DNA.

  13. Acid Catalysis in Basic Solution: A Supramolecular Host PromotesOrthoformate Hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Pluth, Michael D.; Bergman, Robert G.; Raymond, Kenneth N.

    2007-12-12

    Though many enzymes can promote chemical reactions by tuning substrate properties purely through the electrostatic environment of a docking cavity, this strategy has proven challenging to mimic in synthetic host-guest systems. Here we report a highly-charged, water soluble, metal-ligand assembly with a hydrophobic interior cavity that thermodynamically stabilizes protonated substrates and consequently catalyzes the normally acidic hydrolysis of orthoformates in basic solution, with rate accelerations of up to 890-fold. The catalysis reaction obeys Michaelis-Menten kinetics, exhibits competitive inhibition, and the substrate scope displays size selectivity consistent with the constrained binding environment of the molecular host. Synthetic chemists have long endeavored to design host molecules capable of selectively binding slow-reacting substrates and catalyzing their chemical reactions. While synthetic catalysts are often site-specific and require certain properties of the substrate to insure catalysis, enzymes are often able to modify basic properties of the bound substrate such as pK{sub a} in order to enhance reactivity. Two common motifs used by nature to activate otherwise unreactive compounds are the precise arrangement of hydrogen-bonding networks and electrostatic interactions between the substrate and adjacent residues of the protein. Precise arrangement of hydrogen bonding networks near the active sites of proteins can lead to well-tuned pK{sub a}-matching, and can result in pK{sub a} shifts of up to eight units, as shown in bacteriorhodopsin. Similarly, purely electrostatic interactions can greatly favor charged states and have been responsible for pK{sub a} shifts of up to five units for acetoacetate decarboxylase. Attempts have been made to isolate the contributions of electrostatic versus covalent interactions to such pK{sub a} shifts; however this remains a difficult challenge experimentally. This challenge emphasizes the importance of synthesizing

  14. Production of nanocrystalline cellulose from an empty fruit bunches using sulfuric acid hydrolysis: Effect of reaction time on the molecular characteristics

    Science.gov (United States)

    Al-Dulaimi, Ahmed A.; R, Rohaizu; D, Wanrosli W.

    2015-06-01

    Nanocrystalline cellulose (NCC) was isolated from OPEFB pulp via sulfuric acid hydrolysis. The influence of reaction time to the molecular weight and surface charge of the NCC was investigated. Characterization of the product was carried out using zeta potential measurement and gel permeation chromatography test. Zeta potential measurement showed that the surface negative charge significantly increases with increasing reaction time. Gel permeation chromatography test indicates that molecular weight of NCC change variably with increasing of hydrolysis time. (Keywords: Nanocrystalline cellulose; acid hydrolysis; sulfate content; molecular weight)

  15. Co-hydrolysis of hydrothermal and dilute acid pretreated populus slurries to support development of a high-throughput pretreatment system

    Directory of Open Access Journals (Sweden)

    DeMartini Jaclyn D

    2011-07-01

    Full Text Available Abstract Background The BioEnergy Science Center (BESC developed a high-throughput screening method to rapidly identify low-recalcitrance biomass variants. Because the customary separation and analysis of liquid and solids between pretreatment and enzymatic hydrolysis used in conventional analyses is slow, labor-intensive and very difficult to automate, a streamlined approach we term 'co-hydrolysis' was developed. In this method, the solids and liquid in the pretreated biomass slurry are not separated, but instead hydrolysis is performed by adding enzymes to the whole pretreated slurry. The effects of pretreatment method, severity and solids loading on co-hydrolysis performance were investigated. Results For hydrothermal pretreatment at solids concentrations of 0.5 to 2%, high enzyme protein loadings of about 100 mg/g of substrate (glucan plus xylan in the original poplar wood achieved glucose and xylose yields for co-hydrolysis that were comparable with those for washed solids. In addition, although poplar wood sugar yields from co-hydrolysis at 2% solids concentrations fell short of those from hydrolysis of washed solids after dilute sulfuric acid pretreatment even at high enzyme loadings, pretreatment at 0.5% solids concentrations resulted in similar yields for all but the lowest enzyme loading. Conclusions Overall, the influence of severity on susceptibility of pretreated substrates to enzymatic hydrolysis was clearly discernable, showing co-hydrolysis to be a viable approach for identifying plant-pretreatment-enzyme combinations with substantial advantages for sugar production.

  16. Isolation of bacterial cellulose nanocrystalline from pineapple peel waste: Optimization of acid concentration in the hydrolysis method

    Science.gov (United States)

    Anwar, Budiman; Rosyid, Nurul Huda; Effendi, Devi Bentia; Nandiyanto, Asep Bayu Dani; Mudzakir, Ahmad; Hidayat, Topik

    2016-02-01

    Isolation of needle-shaped bacterial cellulose nanocrystalline with a diameter of 16-64 nm, a fiber length of 258-806 nm, and a degree of crystallinity of 64% from pineapple peel waste using an acid hydrolysis process was investigated. Experimental showed that selective concentration of acid played important roles in isolating the bacterial cellulose nanocrystalline from the cellulose source. To achieve the successful isolation of bacterial cellulose nanocrystalline, various acid concentrations were tested. To confirm the effect of acid concentration on the successful isolation process, the reaction conditions were fixed at a temperature of 50°C, a hydrolysis time of 30 minutes, and a bacterial cellulose-to-acid ratio of 1:50. Pineapple peel waste was used as a model for a cellulose source because to the best of our knowledge, there is no report on the use of this raw material for producing bacterial cellulose nanocrystalline. In fact, this material can be used as an alternative for ecofriendly and cost-free cellulose sources. Therefore, understanding in how to isolate bacterial cellulose nanocrystalline from pineapple peel waste has the potential for large-scale production of inexpensive cellulose nanocrystalline.

  17. Hydrolysis and transesterification of parabens in an aqueous solution in the presence of glycerol and boric acid

    Directory of Open Access Journals (Sweden)

    Oldrich Farsa

    2011-06-01

    Full Text Available In a solution containing 0.067% methylparaben, 0.033% propylparaben, 3.4% glycerol and 2.0% boric acid, concentrations of both parabens, 4 hydroxybenzoic acid and 2,3-dihydroxypropyl 4-hydroxybenzoate were monitored for up to 68 months storage. 4-hydroxybenzoic acid is the main hydrolysis product of parabens, while 2,3-dihydroxypropyl 4 hydroxybenzoate was proposed as the main product of transesterification of parabens with glycerol. Results of an HPLC evaluation of parabens, 4-hydroxybenzoic acid and 2,3- dihydroxypropyl 4-hydroxybenzoate showed that the decomposition of 68 months old samples stored at room temperature did not exceed 2.0%. The stability of both parabens in a medicinal preparation of the stated composition has thus been satisfactorily demonstrated after more than 5 years of storage under ambient conditions. The transesterification reaction was shown to influence the chemical stability of parabens to an extent comparable to hydrolysis. Moreover, the presence of 2,3-dihydroxypropyl 4-hydroxybenzoate in the solution containing glycerol and boric acid was confirmed by 1H-NMR spectroscopy.

  18. Electricity production from twelve monosaccharides using microbial fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Catal, Tunc [Department of Biological and Ecological Engineering, Oregon State University, 116 Gilmore Hall, Corvallis, OR 97331 (United States); Department of Wood Science and Engineering, Oregon State University, 102 Richardson Hall, Corvallis, OR 97331 (United States); Department of Molecular Biology and Genetics, Istanbul Technical University, 34469-Maslak, Istanbul (Turkey); Li, Kaichang [Department of Wood Science and Engineering, Oregon State University, 102 Richardson Hall, Corvallis, OR 97331 (United States); Bermek, Hakan [Department of Molecular Biology and Genetics, Istanbul Technical University, 34469-Maslak, Istanbul (Turkey); Liu, Hong [Department of Biological and Ecological Engineering, Oregon State University, 116 Gilmore Hall, Corvallis, OR 97331 (United States)

    2008-01-03

    Direct generation of electricity from monosaccharides of lignocellulosic biomass was examined using air cathode microbial fuel cells (MFCs). Electricity was generated from all carbon sources tested, including six hexoses (D-glucose, D-galactose, D(-)-levulose (fructose), L-fucose, L-rhamnose, and D-mannose), three pentoses (D-xylose, D(-)-arabinose, and D(-)-ribose), two uronic acids (D-galacturonic acid and D-glucuronic acid) and one aldonic acid (D-gluconic acid). The mixed bacterial culture, which was enriched using acetate as a carbon source, adapted well to all carbon sources tested, although the adaptation times varied from 1 to 70 h. The maximum power density obtained from these carbon sources ranged from 1240 {+-} 10 to 2770 {+-} 30 mW m{sup -2} at current density range of 0.76-1.18 mA cm{sup -2}. D-Mannose resulted in the lowest maximum power density, whereas D-glucuronic acid generated the highest one. Coulombic efficiency ranged from 21 to 37%. For all carbon sources tested, the relationship between the maximum voltage output and the substrate concentration appeared to follow saturation kinetics at 120 {omega} external resistance. The estimated maximum voltage output ranged between 0.26 and 0.44 V and half-saturation kinetic constants ranged from 111 to 725 mg L{sup -1}. Chemical oxygen demand (COD) removal was over 80% for all carbon sources tested. Results from this study indicated that lignocellulosic biomass-derived monosaccharides might be a suitable resource for electricity generation using MFC technology. (author)

  19. Electricity production from twelve monosaccharides using microbial fuel cells

    Science.gov (United States)

    Catal, Tunc; Li, Kaichang; Bermek, Hakan; Liu, Hong

    Direct generation of electricity from monosaccharides of lignocellulosic biomass was examined using air cathode microbial fuel cells (MFCs). Electricity was generated from all carbon sources tested, including six hexoses (D-glucose, D-galactose, D(-)-levulose (fructose), L-fucose, L-rhamnose, and D-mannose), three pentoses (D-xylose, D(-)-arabinose, and D(-)-ribose), two uronic acids (D-galacturonic acid and D-glucuronic acid) and one aldonic acid (D-gluconic acid). The mixed bacterial culture, which was enriched using acetate as a carbon source, adapted well to all carbon sources tested, although the adaptation times varied from 1 to 70 h. The maximum power density obtained from these carbon sources ranged from 1240 ± 10 to 2770 ± 30 mW m -2 at current density range of 0.76-1.18 mA cm -2. D-Mannose resulted in the lowest maximum power density, whereas D-glucuronic acid generated the highest one. Coulombic efficiency ranged from 21 to 37%. For all carbon sources tested, the relationship between the maximum voltage output and the substrate concentration appeared to follow saturation kinetics at 120 Ω external resistance. The estimated maximum voltage output ranged between 0.26 and 0.44 V and half-saturation kinetic constants ranged from 111 to 725 mg L -1. Chemical oxygen demand (COD) removal was over 80% for all carbon sources tested. Results from this study indicated that lignocellulosic biomass-derived monosaccharides might be a suitable resource for electricity generation using MFC technology.

  20. Dilute acid pretreatment of sorghum biomass to maximize the hemicellulose hydrolysis with minimized levels of fermentative inhibitors for bioethanol production.

    Science.gov (United States)

    Deshavath, Narendra Naik; Mohan, Mood; Veeranki, Venkata Dasu; Goud, Vaibhav V; Pinnamaneni, Srinivasa Rao; Benarjee, Tamal

    2017-06-01

    Conversion of lignocellulosic biomass into monomeric carbohydrates is economically beneficial and suitable for sustainable production of biofuels. Hydrolysis of lignocellulosic biomass using high acid concentration results in decomposition of sugars into fermentative inhibitors. Thus, the main aim of this work was to investigate the optimum hydrolysis conditions for sorghum brown midrib IS11861 biomass to maximize the pentose sugars yield with minimized levels of fermentative inhibitors at low acid concentrations. Process parameters investigated include sulfuric acid concentration (0.2-1 M), reaction time (30-120 min) and temperature (80-121 °C). At the optimum condition (0.2 M sulfuric acid, 121 °C and 120 min), 97.6% of hemicellulose was converted into xylobiose (18.02 mg/g), xylose (225.2 mg/g), arabinose (20.2 mg/g) with low concentration of furfural (4.6 mg/g). Furthermore, the process parameters were statistically optimized using response surface methodology based on central composite design. Due to the presence of low concentration of fermentative inhibitors, 78.6 and 82.8% of theoretical ethanol yield were attained during the fermentation of non-detoxified and detoxified hydrolyzates, respectively, using Pichia stipitis 3498 wild strain, in a techno-economical way.

  1. G-lignin and hemicellulosic monosaccharides distinctively affect biomass digestibility in rapeseed.

    Science.gov (United States)

    Pei, Yanjie; Li, Yuyang; Zhang, Youbing; Yu, Changbing; Fu, Tingdong; Zou, Jun; Tu, Yuanyuan; Peng, Liangcai; Chen, Peng

    2016-03-01

    In this study, total 19 straw samples from four Brassica species were determined with a diverse cell wall composition and varied biomass enzymatic digestibility under sulfuric acid or lime pretreatment. Correlation analysis was then performed to detect effects of cell wall compositions and wall polymer features (cellulose crystallinity, hemicellulosic monosaccharides and lignin monomers) on rapeseeds biomass digestibility. As a result, coniferyl alcohol (G-lignin) showed a strongly negative effect on biomass saccharification, whereas hemicellulosic monosaccharides (fucose, galactose, arabinose and rhamnose) were positive factors on lignocellulose digestions. Notably, chemical analyses of four typical pairs of samples indicated that hemicellulosic monosaccharides and G-lignin may coordinately influence biomass digestibility in rapeseeds. In addition, Brassica napus with lower lignin content exhibited more efficiency on both biomass enzymatic saccharification and ethanol production, compared with Brassica junjea. Hence, this study has at first time provided a genetic strategy on cell wall modification towards bioenergy rapeseed breeding.

  2. Monosaccharide analysis of succulent leaf tissue in Aloe

    DEFF Research Database (Denmark)

    Grace, Olwen Megan; Dzajic, Amra; Jäger, Anna

    2013-01-01

    in the genus Aloe using a predictive phylogenetic approach. Methodology – Monosaccharide composition was assessed in 31species, representing the morphological and taxonomic diversity of Aloe sensu stricto. Leaf mesophyll polysaccharides were partially hydrolysed in a trifluoroacetic acid (TFA)-SilA assay...

  3. Cholesterol efflux from THP-1 macrophages is impaired by the fatty acid component from lipoprotein hydrolysis by lipoprotein lipase.

    Science.gov (United States)

    Yang, Yanbo; Thyagarajan, Narmadaa; Coady, Breanne M; Brown, Robert J

    2014-09-05

    Lipoprotein lipase (LPL) is an extracellular lipase that primarily hydrolyzes triglycerides within circulating lipoproteins. Macrophage LPL contributes to atherogenesis, but the mechanisms behind it are poorly understood. We hypothesized that the products of lipoprotein hydrolysis generated by LPL promote atherogenesis by inhibiting the cholesterol efflux ability by macrophages. To test this hypothesis, we treated human THP-1 macrophages with total lipoproteins that were hydrolyzed by LPL and we found significantly reduced transcript levels for the cholesterol transporters ATP binding cassette transporter A1 (ABCA1), ABCG1, and scavenger receptor BI. These decreases were likely due to significant reductions for the nuclear receptors liver-X-receptor-α, peroxisome proliferator activated receptor (PPAR)-α, and PPAR-γ. We prepared a mixture of free fatty acids (FFA) that represented the ratios of FFA species within lipoprotein hydrolysis products, and we found that the FFA mixture also significantly reduced cholesterol transporters and nuclear receptors. Finally, we tested the efflux of cholesterol from THP-1 macrophages to apolipoprotein A-I, and we found that the treatment of THP-1 macrophages with the FFA mixture significantly attenuated cholesterol efflux. Overall, these data show that the FFA component of lipoprotein hydrolysis products generated by LPL may promote atherogenesis by inhibiting cholesterol efflux, which partially explains the pro-atherogenic role of macrophage LPL.

  4. Hydrolysis of Cellulose Using Mono-Component Enzymes Shows Synergy during Hydrolysis of Phosphoric Acid Swollen Cellulose (PASC), but Competition on Avicel

    DEFF Research Database (Denmark)

    Andersen, Natalija; Johansen, Katja S.; Michelsen, Michael Locht

    2008-01-01

    the enzymes), increasing as the hydrolysis proceeded. DS of binary exo-/endo-glucanase mixtures, decreased as the mol% of Cel45A increased. In contrast to hydrolysis of PASC, DS values during degradation of Avicel were less then 1, indicating inhibition of the involved enzymes. Thus, our data point...... to competition for the same binding sites between endo- and exo-glucanases, and preferential absorbance of exo-glucanases on crystalline substrates. (c) 2007 Elsevier Inc. All rights reserved....

  5. 柱前衍生高效液相色谱法分析海带岩藻聚糖的单糖及糖醛酸组成%Analysis of Monosaccharides and Uronic Acids in Fucoidon from Seaweed by Pre-column Derivatization High Performance Liquid Chromatography

    Institute of Scientific and Technical Information of China (English)

    王泽文; 冷凯良; 孙伟红; 翟毓秀; 邢丽红; 苗钧魁

    2011-01-01

    High performance liquid chromatography (HPLC) was employed for the analysis of monosaccharide and uronic acids in fucoidon from fresh seaweed with pre-column derivatization. After degradated by 4 mol/L trifluoroacetic acid and derivatived with 1-phenyl-3-methyl-5-pyrazolone(PMP),monosaccharides and uronic acids in fucoidon were separated by reversed-phase HPLC with gradient elution, and monitored by ultraviolet detector at 250 nm. The result show that fucoidon consists of 5 kinds of monosaccharides and 2 kinds of uronic acids. The ratio of mannose, rhamnose, glucuronic acid,galacturonic acid, glucose, galactoses, fucose is 0.03:3.7:0. 22:0.74:0.12: 1.1: 4.1. The developed method is suitable for the rapid analysis of polysaccharide with good reproducibility.%建立了一种柱前衍生高效液相色谱法同时测定海带中岩藻聚糖的单糖及糖醛酸组成的方法.岩藻聚糖经4 mol/L三氟乙酸降解后,用1-苯基-3-甲基-5-吡唑啉酮(PMP)进行衍生化,并采用配有紫外检测器的反相高效液相色谱仪在250 nm波长下进行测定,实现了7种单糖和糖醛酸的良好分离.结果表明:该岩藻聚糖样品由5种单糖和2种糖醛酸组成,其物质量之比为甘露糖:鼠李糖:葡萄糖醛酸:半乳糖醛酸:葡萄糖:半乳糖:岩藻糖=0.03:3.7:0.22:0.74:0.12:1.1:4.1.该方法重现性良好,能够快速对多糖样品进行组成分析.

  6. The effect of acid hydrolysis on the technological functional properties of pinhão (Araucaria brasiliensis starch

    Directory of Open Access Journals (Sweden)

    Roberta Cruz Silveira Thys

    2013-02-01

    Full Text Available Technological functional properties of native and acid-thinned pinhão (seeds of Araucária angustifolia, Brazilian pine starches were evaluated and compared to those of native and acid-thinned corn starches. The starches were hydrolyzed (3.2 mol.L-1 HCl, 44 ºC, 6 hours and evaluated before and after the hydrolysis reaction in terms of formation, melting point and thermo-reversibility of gel starches, retrogradation (in a 30-day period and measurements every three days, paste freezing and thawing stability (after six freezing and thawing cycles, swelling power, and solubility. The results of light transmittance (% of pastes of native and acid-thinned pinhão starches was higher (lower tendency to retrogradation than that obtained for corn starches after similar storage period. Native pinhão starch (NPS presented lower syneresis than native corn starch (NCS when submitted to freeze-thaw cycles. The acid hydrolysis increased the syneresis of the two native varieties under storage at 5 ºC and after freezing and thawing cycles. The solubility of NPS was lower than that of native corn starch at 25, 50, and 70 ºC. However, for the acid-thinned pinhão starch (APS, this property was significantly higher (p < 0.05 when compared to that of acid-thinned corn starch (ACS. From the results obtained, it can be said that the acid treatment was efficient in producing a potential fat substitute from pinhão starch variety, but this ability must be further investigated.

  7. The hydrolysis of polyimides

    Science.gov (United States)

    Hoagland, P. D.; Fox, S. W.

    1973-01-01

    Thermal polymerization of aspartic acid produces a polysuccinimide (I), a chain of aspartoyl residues. An investigation was made of the alkaline hydrolysis of the imide rings of (I) which converts the polyimide to a polypeptide. The alkaline hydrolysis of polyimides can be expected to be kinetically complex due to increasing negative charge generated by carboxylate groups. For this reason, a diimide, phthaloyl-DL-aspartoyl-beta-alanine (IIA) was synthesized for a progressive study of the hydrolysis of polyimides. In addition, this diimide (IIA) can be related to thalidomide and might be expected to exhibit similar reactivity during hydrolysis of the phthalimide ring.

  8. [Study on the acid hydrolysis, fiber remodeling and bionics mineralization of rat tail tendon collagen type Ⅰ].

    Science.gov (United States)

    Zhang, Zhan; Zhang, Chun; Guo, Qiaofeng

    2016-05-25

    Objective: To produce bionic bone material that is consistent with human bone in chemical composition and molecular structure using rat tail tendon collagen type Ⅰ. Methods: The type Ⅰcollagen derived from rat tail was extracted by acetic acid to form collagen fibers. The reconstructed collagen fibers were placed in the mineralized solution to mimic bone mineralization for 2-6 days. Bone mineralization was observed by transmission electron microscopy and electron diffraction.Results: Collagen fibers with characteristic D-Band structure were reconstructed by using rat tail tendon collagen type Ⅰ extracted with acid hydrolysis method. Transmission electron microscopy and electron diffraction showed that calcium hydroxyapatite precursor infiltrated into the collagen fibers, and the collagen fibers were partially mineralized after 2 days of mineralization; the collagen fibers were completely mineralized and bionic bone material of typeⅠ collagen/calcium hydroxyapatite was formed after 6 days of mineralization.Conclusion: The collagen type Ⅰ can be extracted from rat tail tendon by acid hydrolysis method, and can be reformed and mineralized to form the bionic bone material which mimics human bone in chemical composition and the molecular structure.

  9. Dilute phosphoric acid-catalysed hydrolysis of municipal bio-waste wood shavings using autoclave parr reactor system.

    Science.gov (United States)

    Orozco, Angela M; Al-Muhtaseb, Ala'a H; Albadarin, Ahmad B; Rooney, David; Walker, Gavin M; Ahmad, Mohammad N M

    2011-10-01

    The visibility of using municipal bio-waste, wood shavings, as a potential feedstock for ethanol production was investigated. Dilute acid hydrolysis of wood shavings with H₃PO₄ was undertaken in autoclave parr reactor. A combined severity factor (CSF) was used to integrate the effects of hydrolysis times, temperature and acid concentration into a single variable. Xylose concentration reached a maximum value of 17 g/100 g dry mass corresponding to a yield of 100% at the best identified conditions of 2.5 wt.% H₃PO₄, 175 °C and 10 min reaction time corresponding to a CSF of 1.9. However, for glucose, an average yield of 30% was obtained at 5 wt.% H₃PO₄, 200 °C and 10 min. Xylose production increased with increasing temperature and acid concentration, but its transformation to the degradation product furfural was also catalysed by those factors. The maximum furfural formed was 3 g/100 g dry mass, corresponding to the 24% yield. Copyright © 2011 Elsevier Ltd. All rights reserved.

  10. [Optimization of liquid ammonia treatment for enzymatic hydrolysis of Saccharum arundinaceum to fermentable sugars].

    Science.gov (United States)

    Liu, Jianjun; Peng, Hehuan; Zhao, Xiangjun; Cheng, Cheng; Chen, Feng; Shao, Qianjun

    2013-03-01

    China has abundant available marginal land that can be used for cultivation of lignocellulosic energy plants. Saccharum arundinaceum Retz. is a potential energy crop with both high biomass yield and low soil fertility requirements. It can be planted widely as cellulosic ethanol feedstock in southern China. In the present work Saccharum arundinaceum was pretreated by liquid ammonia treatment (LAT) to overcome biomass recalcitrance, followed by enzymatic hydrolysis. The monosaccharide contents (glucose, xylose, and arabinose) of the enzymatic hydrolysate were determined by high performance liquid chromatography. Experimental results show that the optimal LAT pretreatment conditions were 130 0C, 2:1 (W/W) ammonia to biomass ratio, 80% moisture content (dry weight basis) and 5 min residence time. Approximately 69.34% glucan and 82.60% xylan were converted after 72 h enzymatic hydrolysis at 1% glucan loading using 15 FPU/(g of glucan) of cellulase. The yields of glucose and xylose were 573% and 1 056% higher than those of the untreated biomass, and the LAT-pretreated substrates obtained an 8-fold higher of total monosaccharide yield than untreated substrates. LAT pretreatment was an effective to increase the enzymatic digestibility of Saccharum arundinaceum compared to acid impregnated steam explosion and similar to that of acid treatment and ammonia fiber expansion treatment.

  11. Enhanced enzymatic hydrolysis of poplar bark by combined use of gamma ray and dilute acid for bioethanol production

    Science.gov (United States)

    Chung, Byung Yeoup; Lee, Jae Taek; Bai, Hyoung-Woo; Kim, Ung-Jin; Bae, Hyeun-Jong; Gon Wi, Seung; Cho, Jae-Young

    2012-08-01

    Pretreatment of poplar bark with a combination of sulfuric acid (3%, w/w, H2SO4) and gamma irradiation (0-1000 kGy) was performed in an attempt to enhance enzymatic hydrolysis for bioethanol production. The yields of reducing sugar were slightly increased with an increasing irradiation dose, ranging from 35.4% to 51.5%, with a 56.1% reducing sugar yield observed after dilute acid pretreatment. These results clearly showed that soluble sugars were released faster and to a greater extent in dilute acid-pretreated poplar bark than in gamma irradiation-pretreated bark. When combined pretreatment was carried out, a drastic increase in reducing sugar yield (83.1%) was found compared with individual pretreatment, indicating the possibility of increasing the convertibility of poplar bark following combined pretreatment. These findings are likely associated with cellulose crystallinity, lignin modification, and removal of hemicelluloses.

  12. Enzymatic hydrolysis of wood. III. Pretreatment of woods with acidic methanol-water mixture

    Energy Technology Data Exchange (ETDEWEB)

    Shimizu, K.; Usami, K.

    1980-01-01

    Wood meal of Pinus densiflora (I) and Fagus crenata (II) was heated in aqueous methanol containing 0.1-0.6% HCl for 15-90 minutes at 120-170 degrees Centigrade to remove lignin and hydrolyse hemicelluloses. About 75% of the lignin could be removed from (I) and 90% from (II) under appropriate conditions. The cellulosic residues were hydrolysed with Trichoderma viride; it was necessary to remove more than 70% of the lignin from (I) and 80% from (II) for complete hydrolysis of the cellulose. Lignin was precipitated from the hydrolysis liquor by distilling off the methanol. The effects of composition of the MeOH-H/sub 2/O mixture, temperature, reaction time and HC1 concentration were studied.

  13. Production and effect of aldonic acids during enzymatic hydrolysis of lignocellulose at high dry matter content

    OpenAIRE

    Cannella David; Hsieh Chia-wen C; Felby Claus; Jørgensen Henning

    2012-01-01

    Abstract Background The recent discovery of accessory proteins that boost cellulose hydrolysis has increased the economical and technical efficiency of processing cellulose to bioethanol. Oxidative enzymes (e.g. GH61) present in new commercial enzyme preparations have shown to increase cellulose conversion yields. When using pure cellulose substrates it has been determined that both oxidized and unoxidized cellodextrin products are formed. We report the effect of oxidative activity in a comme...

  14. Production and effect of aldonic acids during enzymatic hydrolysis of lignocellulose at high dry matter content

    OpenAIRE

    Cannella, David; Hsieh, Chia-wen C; Felby, Claus; Jørgensen, Henning

    2012-01-01

    Background The recent discovery of accessory proteins that boost cellulose hydrolysis has increased the economical and technical efficiency of processing cellulose to bioethanol. Oxidative enzymes (e.g. GH61) present in new commercial enzyme preparations have shown to increase cellulose conversion yields. When using pure cellulose substrates it has been determined that both oxidized and unoxidized cellodextrin products are formed. We report the effect of oxidative activity in a commercial enz...

  15. Production and effect of aldonic acids during enzymatic hydrolysis of lignocellulose at high dry matter content

    OpenAIRE

    Cannella, David; Hsieh, Chia-wen; Felby, Claus; Jørgensen, Henning

    2012-01-01

    AbstractBackground: The recent discovery of accessory proteins that boost cellulose hydrolysis has increased theeconomical and technical efficiency of processing cellulose to bioethanol. Oxidative enzymes (e.g. GH61) present innew commercial enzyme preparations have shown to increase cellulose conversion yields. When using purecellulose substrates it has been determined that both oxidized and unoxidized cellodextrin products are formed. Wereport the effect of oxidative activity in a commercia...

  16. Hydrolysis of tanned leather wastes under alkaline, acidic and oxidative conditions

    OpenAIRE

    Botić Tatjana; Ilišković Nadežda

    2006-01-01

    Different wastes in large quantities are the outcome or the by-product of processes in the tanning industry. The largest part of solid wastes is collagen based and obtained in the reprocessing steps of tanned and non-tanned products. The quality collagen substance obtained from wastes of the leather industry used as a supporting material in many reprocessing industries. Hydrolysis is the basic step of collagen processing, namely the shortening of its polypeptide chain. The main goal of this i...

  17. Simultaneous determination of acetylsalicylic acid and salicylic acid in human plasma by isocratic high-pressure liquid chromatography with post-column hydrolysis and fluorescence detection.

    Science.gov (United States)

    Hobl, Eva-Luise; Jilma, Bernd; Ebner, Josef; Schmid, Rainer W

    2013-06-01

    A selective, sensitive and rapid high-performance liquid chromatography method with post-column hydrolysis and fluorescence detection was developed for the simultaneous quantification of acetylsalicylic acid and its metabolite salicylic acid in human plasma. Following the addition of 2-hydroxy-3-methoxybenzoic acid as internal standard and simple protein precipitation with acetonitrile, the analytes were separated on a ProntoSIL 120 C18 ace-EPS column (150 × 2 mm, 3 µm) protected by a C8 guard column (5 µm). The mobile phase, 10 mm formic acid in water (pH 2.9) and acetonitrile (70:30, v/v), was used at a flow rate of 0.35 mL/min. After on-line post-column hydrolysis of acetylsalicylic acid (ASA) to salicylic acid (SA) by addition of alkaline solution, the analytes were measured at 290 nm (λex ) and 400 nm (λem ). The method was linear in the concentration ranges between 0.05 and 20 ng/μL for both ASA and SA with a lower limit of quantification of 25 pg/μL for SA and 50 pg/μL for ASA. The limit of detection was 15 pg/μL for SA and 32.5 pg/μL for ASA. The analysis of ASA and SA can be carried out within 8 min; therefore this method is suitable for measuring plasma concentrations of salicylates in clinical routine.

  18. Cellulose pretreatment with 1-n-butyl-3-methylimidazolium chloride for solid acid-catalyzed hydrolysis.

    Science.gov (United States)

    Kim, Soo-Jin; Dwiatmoko, Adid Adep; Choi, Jae Wook; Suh, Young-Woong; Suh, Dong Jin; Oh, Moonhyun

    2010-11-01

    This study has been focused on developing a cellulose pretreatment process using 1-n-butyl-3-methylimidazolium chloride ([bmim]Cl) for subsequent hydrolysis over Nafion(R) NR50. Thus, several pretreatment variables such as the pretreatment period and temperature, and the [bmim]Cl amount were varied. Additionally, the [bmim]Cl-treated cellulose samples were characterized by X-ray diffraction analysis, and their crystallinity index values including CI(XD), CI(XD-CI) and CI(XD-CII) were then calculated. When correlated with these values, the concentrations of total reducing sugars (TRS) obtained by the pretreatment of native cellulose (NC) and glucose produced by the hydrolysis reaction were found to show a distinct relationship with the [CI(NC)-CI(XD)] and CI(XD-CII) values, respectively. Consequently, the cellulose pretreatment step with [bmim]Cl is to loosen a crystalline cellulose through partial transformation of cellulose I to cellulose II and, furthermore, the TRS release, while the subsequent hydrolysis of [bmim]Cl-treated cellulose over Nafion(R) NR50 is effective to convert cellulose II to glucose. Copyright 2010 Elsevier Ltd. All rights reserved.

  19. 菊粉酸降解动力学研究%Kinetic Studies on Acid Catalyzed Hydrolysis of Inulin

    Institute of Scientific and Technical Information of China (English)

    许威; 罗登林; 陈瑞红; 刘建学

    2012-01-01

    通过考察温度、溶液pH值及水分含量对菊粉酸降解的影响,探索菊粉酸水解规律。结果表明:菊粉水溶液在pH 5.0~7.0、温度低于100℃时具有良好的稳定性;但当pH值低于4.0时,菊粉出现明显的水解反应。菊粉溶液在不同温度和pH值下的酸降解动力学表明,其水解反应遵循一级反应动力学方程。利用菊粉凝胶特性考察水分含量与菊粉酸降解的关系,发现相同pH值(pH=3)条件下,水分含量越高,菊粉降解速率越快,凝胶中菊粉降解速率低于菊粉水溶液降解速率。%The effects of temperature,pH and water content on inulin hydrolysis were studied to understand the acid catalyzed hydrolysis process of inulin for industrial production of high-fructose syrup.The results showed that inulin solution had a good thermal stability at a pH value in the range of 5.0-7.0 and a temperature below 100 ℃,while inulin degradation started to occur when the pH was lower than 4.0.The acid catalyzed hydrolysis dynamics of inulin at different levels of temperature and pH showed that the reaction followed the first-order kinetics well.The relation between inulin gel degradation induced by acid and water content was also investigated.At the same pH,the higher water content,the faster inulin hydrolysis,and the degradation rate of inulin was lower in gel than in aqueous solution.

  20. Interaction between amylose and 1-butanol during 1-butanol-hydrochloric acid hydrolysis of normal rice starch.

    Science.gov (United States)

    Hu, Xiuting; Wei, Benxi; Zhang, Bao; Li, Hongyan; Xu, Xueming; Jin, Zhengyu; Tian, Yaoqi

    2013-10-01

    The aim of this study was to examine the interaction between amylose and 1-butanol during the 1-butanol-hydrochloric acid (1-butanol-HCl) hydrolysis of normal rice starch. The interaction model between amylose and 1-butanol was proposed using gas chromatography-mass spectrometry (GC-MS), (13)C cross polarization and magic angle spinning NMR analysis ((13)C CP/MAS NMR), differential scanning calorimetry (DSC), and thermalgravimetric analysis (TGA). GC-MS data showed that another form of 1-butanol existed in 1-butanol-HCl-hydrolyzed normal rice starch, except in the form of free molecules absorbed on the starch granules. The signal of 1-butanol-HCl-hydrolyzed starch at 100.1 ppm appeared in the (13)C CP/MAS NMR spectrum, indicating that the amylose-1-butanol complex was formed. DSC and TGA data also demonstrated the formation of the complex, which significantly affected the thermal properties of normal rice starch. These findings revealed that less dextrin with low molecular weight formed might be attributed to resistance of this complex to acid during 1-butanol-HCl hydrolysis.

  1. {beta}-Secondary and solvent deuterium kinetic isotope effects and the mechanisms of base- and acid-catalyzed hydrolysis of penicillanic acid

    Energy Technology Data Exchange (ETDEWEB)

    Deraniyagala, S.A.; Adediran, S.A.; Pratt, R.F. [Wesleyan Univ., Middletown, CT (United States)

    1995-03-24

    {beta}-Secondary and solvent deuterium kinetic isotope effects have been determined at 25 {degrees}C for the alkaline and acid-catalyzed hydrolysis of penicillanic acid. In order to determine the former isotope effect, [6,6-{sup 2}H{sub 2}]dideuteriopenicillanic acid has been synthesized. In alkaline solution, the former isotope effect was found to be 0.95 {plus_minus} 0.01. These values support the B{sub AC}2 mechanism of hydrolysis with rate-determining formation of the tetrahedral intermediate that has been proposed for other {beta}-lactams. The measured {beta}-secondary kinetic isotope for the acid-catalyzed reaction was 1.00 {plus_minus} 0.01. The data indicates that a likely pathway of acid-catalyzed hydrolysis would be that of an A{sub AC}1 mechanism with an intermediate acylium ion. If this were so, the calculated {beta}-secondary isotope effect per hydrogen coplanar with the breaking C-N bond and corrected for the inductive effect of deuterium would be 1.06 {plus_minus} 0.01. This suggests an early A{sub AC}1 transition state, which would be reasonable in this case because of destabilization of the N-protonated amide with respect to the acylium ion because of ring strain. The absence of specific participation by solvent in the transition state, as would be expected of an A{sub AC}1 but not an associative mechanism, is supported by the strongly inverse solvent deuterium kinetic isotope effect of 0.25 {plus_minus} 0.00 in 1 M HCl and 0.22 {plus_minus} 0.01 in 33.3 wt % H{sub 2}SO{sub 4}. 1 fig., 3 tabs.

  2. Centrifugal partition chromatography in a biorefinery context: Separation of monosaccharides from hydrolysed sugar beet pulp.

    Science.gov (United States)

    Ward, David P; Cárdenas-Fernández, Max; Hewitson, Peter; Ignatova, Svetlana; Lye, Gary J

    2015-09-11

    A critical step in the bioprocessing of sustainable biomass feedstocks, such as sugar beet pulp (SBP), is the isolation of the component sugars from the hydrolysed polysaccharides. This facilitates their subsequent conversion into higher value chemicals and pharmaceutical intermediates. Separation methodologies such as centrifugal partition chromatography (CPC) offer an alternative to traditional resin-based chromatographic techniques for multicomponent sugar separations. Highly polar two-phase systems containing ethanol and aqueous ammonium sulphate are examined here for the separation of monosaccharides present in hydrolysed SBP pectin: l-rhamnose, l-arabinose, d-galactose and d-galacturonic acid. Dimethyl sulfoxide (DMSO) was selected as an effective phase system modifier improving monosaccharide separation. The best phase system identified was ethanol:DMSO:aqueous ammonium sulphate (300gL(-1)) (0.8:0.1:1.8, v:v:v) which enabled separation of the SBP monosaccharides by CPC (200mL column) in ascending mode (upper phase as mobile phase) with a mobile phase flow rate of 8mLmin(-1). A mixture containing all four monosaccharides (1.08g total sugars) in the proportions found in hydrolysed SBP was separated into three main fractions; a pure l-rhamnose fraction (>90%), a mixed l-arabinose/d-galactose fraction and a pure d-galacturonic acid fraction (>90%). The separation took less than 2h demonstrating that CPC is a promising technique for the separation of these sugars with potential for application within an integrated, whole crop biorefinery.

  3. Pretreatment of Sugar Beet Pulp with Dilute Sulfurous Acid is Effective for Multipurpose Usage of Carbohydrates.

    Science.gov (United States)

    Kharina, M; Emelyanov, V; Mokshina, N; Ibragimova, N; Gorshkova, T

    2016-05-01

    Sulfurous acid was used for pretreatment of sugar beet pulp (SBP) in order to achieve high efficiency of both extraction of carbohydrates and subsequent enzymatic hydrolysis of the remaining solids. The main advantage of sulfurous acid usage as pretreatment agent is the possibility of its regeneration. Application of sulfurous acid as hydrolyzing agent in relatively low concentrations (0.6-1.0 %) during a short period of time (10-20 min) and low solid to liquid ratio (1:3, 1:6) allowed effective extraction of carbohydrates from SBP and provided positive effect on subsequent enzymatic hydrolysis. The highest obtained concentration of reducing substances (RS) in hydrolysates was 8.5 %; up to 33.6 % of all carbohydrates present in SBP could be extracted. The major obtained monosaccharides were arabinose and glucose (9.4 and 7.3 g/l, respectively). Pretreatment of SBP with sulfurous acid increased 4.6 times the yield of glucose during subsequent enzymatic hydrolysis of remaining solids with cellulase cocktail, as compared to the untreated SBP. Total yield of glucose during SBP pretreatment and subsequent enzymatic hydrolysis amounted to 89.4 % of the theoretical yield. The approach can be applied directly to the wet SBP. Hydrolysis of sugar beet pulp with sulfurous acid is recommended for obtaining of individual monosaccharides, as well as nutritional media.

  4. In situ pressurized biphase acid hydrolysis, a promising approach to produce bioactive diosgenin from the tubers of Dioscorea Zingiberensis

    Directory of Open Access Journals (Sweden)

    Huan Yang

    2015-01-01

    Full Text Available Background: The tubers of Dioscorea zingiberensis, is the most favorable plant material for the production of diosgenin, an important bioactive steroidal sapogenin and requisite precursor of cortin, contraceptive and sex hormone, which is the only desired product after steroidal saponins from the tubers are hydrolyzed. Objective: A novel technology, in situ pressurized biphase acid hydrolysis was constructed for the first time to simplify extraction process, increase extraction yield and decrease the consumption of mineral acids. Materials and Methods: The method developed in this study has been optimized and verified through orthogonal design for experiments, in which the effect and their significance of four factors including molarity of acid, temperature, extraction duration and sample quantity have been investigated. Then, the comparison was conducted among the newly developed method and other reported methods. The diosgenin was also isolated by column chromatography, followed by mass spectrometry and nuclear magnetic resonance analysis for structural confirmation. Results: It was found that temperature is the factor of the most influence and the highest extraction yield at 2.21% has been achieved while the hydrolysis was performed at 140°C for 1.5 h in 0.20M H2SO4 solution with petroleum ether under an uncontrolled pressurized condition. And, compared to the others, the increment in the extraction yield of new method was 20.8 ~ 74.0%, and the consumption of H2SO4 was reduced by 17 times at most. Conclusion: This method is a much cleaner and more efficient approach for extraction of diosgenin from the tubers, and is promising to be applied in pharmaceutical industry.

  5. Acid hydrolysis and molecular density of phytoglycogen and liver glycogen helps understand the bonding in glycogen α (composite particles.

    Directory of Open Access Journals (Sweden)

    Prudence O Powell

    Full Text Available Phytoglycogen (from certain mutant plants and animal glycogen are highly branched glucose polymers with similarities in structural features and molecular size range. Both appear to form composite α particles from smaller β particles. The molecular size distribution of liver glycogen is bimodal, with distinct α and β components, while that of phytoglycogen is monomodal. This study aims to enhance our understanding of the nature of the link between liver-glycogen β particles resulting in the formation of large α particles. It examines the time evolution of the size distribution of these molecules during acid hydrolysis, and the size dependence of the molecular density of both glucans. The monomodal distribution of phytoglycogen decreases uniformly in time with hydrolysis, while with glycogen, the large particles degrade significantly more quickly. The size dependence of the molecular density shows qualitatively different shapes for these two types of molecules. The data, combined with a quantitative model for the evolution of the distribution during degradation, suggest that the bonding between β into α particles is different between phytoglycogen and liver glycogen, with the formation of a glycosidic linkage for phytoglycogen and a covalent or strong non-covalent linkage, most probably involving a protein, for glycogen as most likely. This finding is of importance for diabetes, where α-particle structure is impaired.

  6. Efficient hydrolysis of cellulose over a magnetic lignin-derived solid acid catalyst in 1-butyl-3-methylimidazolium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Lei; Wu, Zhen; Xu, Jiaxing; Zhou, Shouyong; Tang, Guodong [Huaiyin Normal University, Huaian (China)

    2016-04-15

    A green and efficient strategy for the hydrolysis of cellulose was developed by using a magnetic lignin-derived solid acid catalyst (MLC-SO{sub 3}H) in the presence of ionic liquid 1-butyl-3-methylimidazolium chloride ([BMIM]Cl). The results indicated that reaction temperature, reaction time, catalyst loading and water content have a big influence on the yield of total reducing sugars (TRS). By optimizing these reaction parameters, 69.3% TRS yield was observed at 140 .deg. C for 150 min with the addition of 40 wt% MLC-SO{sub 3}H and 1 wt% water. More importantly, MLC-SO{sub 3}H could be easily separated from the reaction mixture with an external magnet and could be repeatedly used five times without an obvious loss of catalytic activity, demonstrating that it possessed excellent recyclability. Furthermore, a plausible mechanism involving three consecutive processes of dissolution, adsorption and catalysis for the hydrolysis of cellulose in [BMIM]Cl over a catalyst of MLC-SO{sub 3}H was also proposed.

  7. Acid Hydrolysis and Molecular Density of Phytoglycogen and Liver Glycogen Helps Understand the Bonding in Glycogen α (Composite) Particles

    Science.gov (United States)

    Powell, Prudence O.; Sullivan, Mitchell A.; Sheehy, Joshua J.; Schulz, Benjamin L.; Warren, Frederick J.; Gilbert, Robert G.

    2015-01-01

    Phytoglycogen (from certain mutant plants) and animal glycogen are highly branched glucose polymers with similarities in structural features and molecular size range. Both appear to form composite α particles from smaller β particles. The molecular size distribution of liver glycogen is bimodal, with distinct α and β components, while that of phytoglycogen is monomodal. This study aims to enhance our understanding of the nature of the link between liver-glycogen β particles resulting in the formation of large α particles. It examines the time evolution of the size distribution of these molecules during acid hydrolysis, and the size dependence of the molecular density of both glucans. The monomodal distribution of phytoglycogen decreases uniformly in time with hydrolysis, while with glycogen, the large particles degrade significantly more quickly. The size dependence of the molecular density shows qualitatively different shapes for these two types of molecules. The data, combined with a quantitative model for the evolution of the distribution during degradation, suggest that the bonding between β into α particles is different between phytoglycogen and liver glycogen, with the formation of a glycosidic linkage for phytoglycogen and a covalent or strong non-covalent linkage, most probably involving a protein, for glycogen as most likely. This finding is of importance for diabetes, where α-particle structure is impaired. PMID:25799321

  8. Starch hydrolysis by Strepto-coccus equinus.

    Science.gov (United States)

    DUNICAN, L K; SEELEY, H W

    1962-02-01

    Dunican, Lawrence K. (Cornell University, Ithaca, N. Y.) and Harry W. Seeley. Starch hydrolysis by Streptococcus equinus. J. Bacteriol. 82:264-269. 1962.-In a study of starch hydrolysis by strains of Streptococcus equinus, 52 isolates were obtained and their amylolytic abilities determined. It was found that all the strains could hydrolyze starch to some extent when grown in the presence of an easily fermentable carbohydrate, viz., glucose. Without this carbohydrate the organisms did not hydrolyze starch. The hydrolysis of starch was inhibited when the organisms were grown in an atmosphere of 5% CO(2) and 95% N(2), even if grown in the presence of a fermentable monosaccharide. S. bovis, which was used as a reference organism, readily hydrolyzed starch in the absence of monosaccharides and in atmospheres containing CO(2). In no instance did S. equinus hydrolyze the starch to the level of reducing sugars. Negligible amounts of reducing sugars were recovered when the cell-free filtrates of S. equinus were incubated with starch. With S. bovis, the yield of reducing sugars under such conditions was almost quantitative. These facts extend further the differences between these related organisms. The ability to synthesize an internal starchlike polysaccharide was noted in most of the strains of S. equinus. Synthesis was found when the organisms were grown on maltose or on a starch medium containing a small amount of fermentable monosaccharide.

  9. Analysis of saccharification in Brachypodium distachyon stems under mild conditions of hydrolysis

    Directory of Open Access Journals (Sweden)

    Statham Emily R

    2008-10-01

    Full Text Available Abstract Background Brachypodium distachyon constitutes an excellent model species for grasses. It is a small, easily propagated, temperate grass with a rapid life cycle and a small genome. It is a self-fertile plant that can be transformed with high efficiency using Agrobacteria and callus derived from immature embryos. In addition, considerable genetic and genomic resources are becoming available for this species in the form of mapping populations, large expressed sequence tag collections, T-DNA insertion lines and, in the near future, the complete genome sequence. The development of Brachypodium as a model species is of particular value in the areas of cell wall and biomass research, where differences between dicots and grasses are greatest. Here we explore the effect of mild conditions of pretreatment and hydrolysis in Brachypodium stem segments as a contribution for the establishment of sensitive screening of the saccharification properties in different genetic materials. Results The non-cellulosic monosaccharide composition of Brachypodium is closely related to grasses of agricultural importance and significantly different from the dicot model Arabidopsis thaliana. Diluted acid pretreatment of stem segments produced significant release of sugars and negatively affected the amount of sugars obtained by enzymatic hydrolysis. Monosaccharide and oligosaccharide analysis showed that the hemicellulose fraction is the main target of the enzymatic activity under the modest hydrolytic conditions used in our assays. Scanning electron microscopy analysis of the treated materials showed progressive exposure of fibrils in the stem segments. Conclusion Results presented here indicate that under mild conditions cellulose and hemicellulose are hydrolysed to differing extents, with hemicellulose hydrolysis predominating. We anticipate that the sub-optimal conditions for hydrolysis identified here will provide a sensitive assay to detect variations in

  10. Acid and Base Catalyzed Hydrolysis of Cyanophycin for the Biobased Production of Nitrogen Containing Chemicals

    NARCIS (Netherlands)

    Könst, P.M.; Scott, E.L.; Franssen, M.C.R.; Sanders, J.P.M.

    2011-01-01

    While growing on side-streams of the agro-industries, engineered microorganisms can produce ethanol and simultaneously bind L-aspartic acid and L-arginine in equimolar amounts in the polyamino acid cyanophycin. In this way, widely available amino acids can be isolated and utilized as an alternative

  11. [Optimization of alkaline hydrolysis based on the side chain of diethyl ester 4-amino-N(5)-formyl-N(8), N(10)-dideazatetrahydrofolic acid].

    Science.gov (United States)

    Yuan, M M; Wang, M; Liu, J Y; Zhang, Z L

    2017-08-18

    single ester hydrolysis product and amide bond hydrolysis product, but also improve the yield of the hydrolysis reaction. We have developed an efficient reaction for the hydrolysis of diethyl ester 4-amino-N(5)-formyl-N(8), N(10)-dideazatetrahydro. Since the final step of the synthesis of classical folic acid antagonists is always the catalyzed hydrolysis of the side chain glutamate, the reaction also has great significance for anti-folic acid anti-tumor inhibitors synthesis.

  12. Monosaccharide composition of Herniaria glabra L. and Herniaria polygama J.Gay

    Directory of Open Access Journals (Sweden)

    Kozachok Solomiia

    2016-09-01

    Full Text Available The plants from Herniaria genus (Caryophyllaceae family are mainly applied as diuretic agents for the treatment of kidney and gall-stones, gouts, urinary tract infections, hypertension and diabetes. The most widely spread species in Europe is Herniaria glabra L. (HG. Herniaria polygama J.Gay (HP is found growing from Eastern Europe to Asia. Surprisingly, no work has been reported on the analysis of primary metabolites of HP yet and there is only a limited data on HG. The aim of our study was to establish the monosaccharide composition after a complete hydrolysis and in a free state in the entire herbs of HG and HP harvested in the western and central parts of Ukraine. The carbohydrates were separated by gas chromatography-mass spectrometry after conversion into volatile derivatives as aldononitrile acetate. As a result, the monosaccharide composition after a total hydrolysis was established with the contribution of the following components: D-rhamnose, D-arabinose, D-fucose, D-xylose, D-manose, D-glucose, D-galactose, D-pinitol, myo-inisitol, D-mannitol, D-dulcitol. In a free state it was detected: D-fructose, D-glucose, D-galactose, D-pinitol, myo-inisitol, D-mannitol and D-saccharose. The following monosaccharides were found in the most abundant quantities in HG and HP respectively: glucose was determined as the major component – 33.40 and 22.80 mg/g, the second dominant sugar was pinitol – 16.80 and 18.07 mg/g, followed by galactose – 13.88 mg/g in HG and arabinose – 8.13 mg/g in HP. Sugars were determined in these plant species for the first time and this finding shed new light on their pharmacological application.

  13. Comparative decomposition kinetics of neutral monosaccharides by microwave and induction heating treatments.

    Science.gov (United States)

    Tsubaki, Shuntaro; Oono, Kiriyo; Onda, Ayumu; Yanagisawa, Kazumichi; Azuma, Jun-ichi

    2013-06-28

    The stabilities of five neutral monosaccharides (glucose, galactose, mannose, arabinose, and xylose) were kinetically compared after the molecules were submitted to microwave heating (internal heating) and induction heating (external heating) under completely identical thermal histories by employing PID (proportional, integral, and derivative) temperature controlled ovens and homogeneous mixing. By heating in water at 200°C, the rate constants for the decomposition reactions varied from 2.13×10(-4) to 3.87×10(-4)s(-1) for microwave heating; however, the values increased by 1.1- to 1.5-fold for induction heating. Similarly, in a dilute (0.8%) sulfuric acid solution, the decomposition rate constants varied from 0.61×10(-3) to 2.00×10(-3)s(-1) for microwave heating; however, the values increased by 1.5- to 2.2-fold for induction heating. The results show that microwave heating imparts greater stability to neutral monosaccharides than does induction heating. The undesirable decomposition of monosaccharides at the surface boundary of reactor walls may have increased the probability of monosaccharide decomposition during induction heating.

  14. Structural characterization of Astragalus polysaccharides using partial acid hydrolysis-hydrophilic interaction liquid chromatography-mass spectrometry%基于部分酸水解-亲水作用色谱-质谱的黄芪多糖结构表征

    Institute of Scientific and Technical Information of China (English)

    梁图; 傅青; 辛华夏; 李芳冰; 金郁; 梁鑫淼

    2014-01-01

    Water-soluble polysaccharides from traditional Chinese medicine(TCM)have prop-erties of broad-spectrum treatment and low toxicity,making them as important components in natural medicines and health products. In order to solve the problem of polysaccharides charac-terization caused by their complex structures,a“bottom-up”approach was developed to com-plete the characterization of polysaccharides from Astragalus. Firstly,Astragalus pieces were extracted with hot water and then were precipitated by ethanol to obtain Astragalus polysaccha-rides. Secondly,a partial acid hydrolysis method was carried out and the effects of time,acid concentration and temperature on hydrolysis were investigated. The degree of hydrolysis increased along with the increase of hydrolysis time and acid concentration. The temperature played a great role in the hydrolysis process. No hydrolysis of the polysaccharides occurred at low temperature,while the polysaccharides were almost hydrolyzed to monosaccharide at high temperature. Under the optimum hydrolysis conditions(4 h,1. 5 mol/L trifluoroacetic acid, and 80 ℃),Astragalus polysaccharides were hydrolyzed to characteristic oligosaccharide frag-ments. At last,a hydrophilic liquid chromatography-mass spectrometry method was used for the separation and structural characterization of the polysaccharide hydrolysates. The results showed that the resulting polysaccharides were mainly 1→4 linear glucan,and gluco-oligosac-charides with the degrees of polymerization(DP ) of 4-11 were obtained after partial acid hydrolysis. The significance of this study is that it is the guidance for the characterization of other TCM polysaccharides.%来自中药的水溶性多糖具有广谱治疗和低毒性特点,是天然药物及保健品研发中的重要组成部分。针对中药多糖结构复杂、难以表征的问题,本文以中药黄芪中的多糖为研究对象,采用“自下而上”法完成对黄芪多糖的表征。首先使用部分

  15. Response surface optimization of corn stover pretreatment using dilute phosphoric acid for enzymatic hydrolysis and ethanol production.

    Science.gov (United States)

    Avci, Ayse; Saha, Badal C; Dien, Bruce S; Kennedy, Gregory J; Cotta, Michael A

    2013-02-01

    Dilute H(3)PO(4) (0.0-2.0%, v/v) was used to pretreat corn stover (10%, w/w) for conversion to ethanol. Pretreatment conditions were optimized for temperature, acid loading, and time using central composite design. Optimal pretreatment conditions were chosen to promote sugar yields following enzymatic digestion while minimizing formation of furans, which are potent inhibitors of fermentation. The maximum glucose yield (85%) was obtained after enzymatic hydrolysis of corn stover pretreated with 0.5% (v/v) acid at 180°C for 15min while highest yield for xylose (91.4%) was observed from corn stover pretreated with 1% (v/v) acid at 160°C for 10min. About 26.4±0.1g ethanol was produced per L by recombinant Escherichia coli strain FBR5 from 55.1±1.0g sugars generated from enzymatically hydrolyzed corn stover (10%, w/w) pretreated under a balanced optimized condition (161.81°C, 0.78% acid, 9.78min) where only 0.4±0.0g furfural and 0.1±0.0 hydroxylmethyl furfural were produced.

  16. Green synthesis of bacterial cellulose via acetic acid pre-hydrolysis liquor of agricultural corn stalk used as carbon source.

    Science.gov (United States)

    Cheng, Zheng; Yang, Rendang; Liu, Xu; Liu, Xiao; Chen, Hua

    2017-06-01

    Herein, bacterial cellulose (BC) was synthesized by acetobacter xylinum via organic acid pre-hydrolysis liquor of agricultural corn stalk used as carbon source. Acetic acid was applied to pretreat the corn stalk, then, the prehydrolysate was detoxified by sequential steps of activated carbon and ion exchange resin treatment prior to use as carbon source to cultivate acetobacter xylinum. Moreover, the recovery of acetic acid was achieved for facilitating the reduction of cost. The results revealed that the combination method of detoxification treatment was very effective for synthesis of BC, yield could be up to 2.86g/L. SEM analysis showed that the diameter size of BC between 20 and 70mm. In summary, the process that bacterial cellulose was biosynthesized via prehydrolysate from agricultural corn stalk used as carbon source is feasible, and the ability to recover organic acid make it economical, sustainable and green, which fits well into the biorefinery concept. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Imidase catalyzing desymmetric imide hydrolysis forming optically active 3-substituted glutaric acid monoamides for the synthesis of gamma-aminobutyric acid (GABA) analogs.

    Science.gov (United States)

    Nojiri, Masutoshi; Hibi, Makoto; Shizawa, Hiroaki; Horinouchi, Nobuyuki; Yasohara, Yoshihiko; Takahashi, Satomi; Ogawa, Jun

    2015-12-01

    The recent use of optically active 3-substituted gamma-aminobutyric acid (GABA) analogs in human therapeutics has identified a need for an efficient, stereoselective method of their synthesis. Here, bacterial strains were screened for enzymes capable of stereospecific hydrolysis of 3-substituted glutarimides to generate (R)-3-substituted glutaric acid monoamides. The bacteria Alcaligenes faecalis NBRC13111 and Burkholderia phytofirmans DSM17436 were discovered to hydrolyze 3-(4-chlorophenyl) glutarimide (CGI) to (R)-3-(4-chlorophenyl) glutaric acid monoamide (CGM) with 98.1% enantiomeric excess (e.e.) and 97.5% e.e., respectively. B. phytofirmans DSM17436 could also hydrolyze 3-isobutyl glutarimide (IBI) to produce (R)-3-isobutyl glutaric acid monoamide (IBM) with 94.9% e.e. BpIH, an imidase, was purified from B. phytofirmans DSM17436 and found to generate (R)-CGM from CGI with specific activity of 0.95 U/mg. The amino acid sequence of BpIH had a 75% sequence identity to that of allantoinase from A. faecalis NBRC13111 (AfIH). The purified recombinant BpIH and AfIH catalyzed (R)-selective hydrolysis of CGI and IBI. In addition, a preliminary investigation of the enzymatic properties of BpIH and AfIH revealed that both enzymes were stable in the range of pH 6-10, with an optimal pH of 9.0, stable at temperatures below 40 °C, and were not metalloproteins. These results indicate that the use of this class of hydrolase to generate optically active 3-substituted glutaric acid monoamide could simplify the production of specific chiral GABA analogs for drug therapeutics.

  18. Improving stability and activity of cross-linked enzyme aggregates based on polyethylenimine in hydrolysis of fish oil for enrichment of polyunsaturated fatty acids.

    Science.gov (United States)

    Yan, Jinyong; Gui, Xiaohua; Wang, Guilong; Yan, Yunjun

    2012-02-01

    Cross-linking of enzyme aggregates from recombinant Geotrichum sp. lipase based on polyethylenimine (PEI) was applied to hydrolyze fish oil for enrichment of polyunsaturated fatty acids successfully. Through acetone precipitation and cross-linking of physical aggregates using glutaraldehyde in the presence of PEI, firmly cross-linked enzyme aggregates (PEI-CLEAs) were prepared. They could maintain more than 65% of relative hydrolysis degree after incubation in the range of 50-55 °C for 4 h and maintain more than 85% of relative hydrolysis degree after being treated by acetone, tert-butyl alcohol and octane for 4 h. PEI-CLEAs increased hydrolysis degree to 42% from 12% by free lipase. After five batch reactions, PEI-CLEAs still maintained 72% of relative hydrolysis degree. Hydrolysis of fish oil by PEI-CLEAs produced glycerides containing concentrated EPA and DHA in good yield. PEI-CLEAs had advantages over general CLEAs and free lipase in initial reaction rate, hydrolysis degree, thermostability, organic solvent tolerance and reusability.

  19. Analysis of GTPases carrying hydrophobic amino acid substitutions in lieu of the catalytic glutamine: implications for GTP hydrolysis.

    Science.gov (United States)

    Mishra, Rajeev; Gara, Sudheer Kumar; Mishra, Shambhavi; Prakash, Balaji

    2005-05-01

    Ras superfamily GTP-binding proteins regulate important signaling events in the cell. Ras, which often serves as a prototype, efficiently hydrolyzes GTP in conjunction with its regulator GAP. A conserved glutamine plays a vital role in GTP hydrolysis in most GTP-binding proteins. Mutating this glutamine in Ras has oncogenic effects, since it disrupts GTP hydrolysis. The analysis presented here is of GTP-binding proteins that are a paradox to oncogenic Ras, since they have the catalytic glutamine (Glncat) substituted by a hydrophobic amino acid, yet can hydrolyze GTP efficiently. We term these proteins HAS-GTPases. Analysis of the amino acid sequences of HAS-GTPases reveals prominent presence of insertions around the GTP-binding pocket. Homology modeling studies suggest an interesting means to achieve catalysis despite the drastic hydrophobic substitution replacing the key Glncat of Ras-like GTPases. The substituted hydrophobic residue adopts a "retracted conformation," where it is positioned away from the GTP, as its role in catalysis would be unproductive. This conformation is further stabilized by interactions with hydrophobic residues in its vicinity. These interacting residues are strongly conserved and hydrophobic in all HAS-GTPases, and correspond to residues Asp92 and Tyr96 of Ras. An experimental support for the "retracted conformation" of Switch II arises from the crystal structures of Ylqf and hGBP1. This conformation allows us to hypothesize that, unlike in classical GTPases, catalytic residues could be supplied by regions other than the Switch II (i.e., either the insertions or a neighboring domain).

  20. VLDL hydrolysis by LPL activates PPAR-alpha through generation of unbound fatty acids.

    Science.gov (United States)

    Ruby, Maxwell A; Goldenson, Benjamin; Orasanu, Gabriela; Johnston, Thomas P; Plutzky, Jorge; Krauss, Ronald M

    2010-08-01

    Recent evidence suggests that lipoproteins serve as circulating reservoirs of peroxisomal proliferator activated receptor (PPAR) ligands that are accessible through lipolysis. The present study was conducted to determine the biochemical basis of PPAR-alpha activation by lipolysis products and their contribution to PPAR-alpha function in vivo. PPAR-alpha activation was measured in bovine aortic endothelial cells following treatment with human plasma, VLDL lipolysis products, or oleic acid. While plasma failed to activate PPAR-alpha, oleic acid performed similarly to VLDL lipolysis products. Therefore, fatty acids are likely to be the PPAR-alpha ligands generated by VLDL lipolysis. Indeed, unbound fatty acid concentration determined PPAR-alpha activation regardless of fatty acid source, with PPAR-alpha activation occurring only at unbound fatty acid concentrations that are unachievable under physiological conditions without lipase action. In mice, a synthetic lipase inhibitor (poloxamer-407) attenuated fasting-induced changes in expression of PPAR-alpha target genes. Apolipoprotein CIII (apoCIII), an endogenous inhibitor of lipoprotein and hepatic lipase, regulated access to the lipoprotein pool of PPAR-alpha ligands, because addition of exogenous apoCIII inhibited, and removal of endogenous apoCIII potentiated, lipolytic PPAR-alpha activation. These data suggest that the PPAR-alpha response is generated by unbound fatty acids released locally by lipase activity and not by circulating plasma fatty acids.

  1. Titan's Primordial Soup: Formation of Amino Acids via Low-Temperature Hydrolysis of Tholins

    Science.gov (United States)

    Neish, Catherine D.; Somogyi, Árpád; Smith, Mark A.

    2010-04-01

    Titan organic haze analogues, or "tholins," produce biomolecules when hydrolyzed at low temperature over long timescales. By using a combination of high-resolution mass spectroscopy and tandem mass spectrometry fragmentation techniques, four amino acids were identified in a tholin sample that had been hydrolyzed in a 13 wt % ammonia-water solution at 253 ± 1 K and 293 ± 1 K for 1 year. These four species have been assigned as the amino acids asparagine, aspartic acid, glutamine, and glutamic acid. This represents the first detection of biologically relevant molecules created under conditions thought to be similar to those found in impact melt pools and cryolavas on Titan, which are at a stage of chemical evolution not unlike the "primordial soup" of the early Earth. Future missions to Titan should therefore carry instrumentation capable of, but certainly not limited to, detecting amino acids and other prebiotic molecules on Titan's surface.

  2. Improving enzymatic hydrolysis of corn stover pretreated by ethylene glycol-perchloric acid-water mixture.

    Science.gov (United States)

    He, Yu-Cai; Liu, Feng; Gong, Lei; Lu, Ting; Ding, Yun; Zhang, Dan-Ping; Qing, Qing; Zhang, Yue

    2015-02-01

    To improve the enzymatic saccharification of lignocellulosic biomass, a mixture of ethylene glycol-HClO4-water (88.8:1.2:10, w/w/w) was used for pretreating corn stover in this study. After the optimization in oil-bath system, the optimum pretreatment temperature and time were 130 °C and 30 min, respectively. After the saccharification of 10 g/L pretreated corn stover for 48 h, the saccharification rate was obtained in the yield of 77.4 %. To decrease pretreatment temperature and shorten pretreatment time, ethylene glycol-HClO4-water (88.8:1.2:10, w/w/w) media under microwave irradiation was employed to pretreat corn stover effectively at 100 °C and 200 W for 5 min. Finally, the recovered hydrolyzates containing glucose obtained from the enzymatic hydrolysis of pretreated corn stovers could be fermented into ethanol efficiently. These results would be helpful for developing a cost-effective pretreatment combined with enzymatic saccharification of cellulosic materials for the production of lignocellulosic ethanol.

  3. Aroma components of acid-hydrolyzed vegetable protein made by partial hydrolysis of rice bran protein.

    Science.gov (United States)

    Jarunrattanasri, Arporn; Theerakulkait, Chockchai; Cadwallader, Keith R

    2007-04-18

    Hydrolyzed vegetable protein (HVP) was prepared from rice bran protein concentrate (RBPc) by partial hydrolysis with aqueous 0.5 N HCl at 95 degrees C for 12 or 36 h (H-RBPc-12 and H-RBPc-36, respectively). Aroma components of the RBPc and the HVPs were characterized by gas chromatography-olfactometry, gas chromatography-mass spectrometry, aroma extract dilution analysis, and calculation of odor activity values (OAVs). The predominant odorants in RBPc were 3-methylbutanal, hexanal, 2-aminoacetophenone, (E)-2-nonenal, phenylacetaldehyde, and beta-damascenone. Among these, the odor of 2-aminoacetophenone, present at 59 ng/g in RBPc, was reminiscent of the typical odor of RBPc. Most of the predominant odorants had higher log3FD factors in the H-RBPc-36 as compared to H-RBPc-12. Aroma impact compounds of H-RBPc-12 and H-RBPc-36 were 2-methoxyphenol (guaiacol), 4-hydroxy-2,5-dimethyl-3(2H)furanone, 3-hydroxy-4,5-dimethyl-2(5H)furanone (sotolon), vanillin, 3-methylbutanal, (E)-2-nonenal, 4-vinyl-2-methoxyphenol (p-vinylguaiacol), and beta-damascenone. Guaiacol had the highest OAV values of 2770 and 17650 in H-RBPc-12 and H-RBPc-36, respectively.

  4. Revisiting the Brønsted acid catalysed hydrolysis kinetics of polymeric carbohydrates in ionic liquids by in situ ATR-FTIR spectroscopy

    DEFF Research Database (Denmark)

    Kunov-Kruse, Andreas Jonas; Riisager, Anders; Shunmugavel, Saravanamurugan;

    2013-01-01

    A new versatile method to measure rates and determine activation energies for the Brønsted acid catalysed hydrolysis of cellulose and cellobiose (and other polymeric carbohydrates) in ionic liquids is demonstrated by following the C–O stretching band of the glycoside bond with in situ ATR-FTIR. A...

  5. Effect of low severity dilute-acid pretreatment of barley straw and decreased enzyme loading hydrolysis on the production of fermentable substrates and the release of inhibitory compounds

    NARCIS (Netherlands)

    Panagiotopoulos, I.A.; Lignos, G.D.; Bakker, R.R.C.; Koukios, E.G.

    2012-01-01

    The objective of this work was to investigate the feasibility of combining low severity dilute-acid pretreatment of barley straw and decreased enzyme loading hydrolysis for the high production of fermentable substrates and the low release of inhibitory compounds. For most of the pretreatments at 160

  6. Hydrolysis of Straw in Ionic Liquids with Acid as Catalyst under Microwave Irradiation

    National Research Council Canada - National Science Library

    Zhang, Yuanjing; Wei, Gang; Yu, Guangyi; Qiao, Ning

    2015-01-01

      With ionic liquids as solvents and corn straw as raw material, different processes of lignocellulose pretreatment with acid as catalyst were studied under conventional heating/microwave irradiation...

  7. Fuel ethanol production from corn stover under optimized dilute phosphoric acid pretreatment and enzymatic hydrolysis

    Science.gov (United States)

    Ethanol is a renewable oxygenated fuel. Dilute acid pretreatment is a promising pretreatment technology for conversion of lignocellulosic biomass to fuel ethanol. Generation of fermentable sugars from corn stover involves pretreatment and enzymatic saccharification. Pretreatment is crucial as nat...

  8. Amino Acids Production from Fish Proteins Hydrolysis in Subcritical Water%近临界水中水解鱼蛋白制备氨基酸

    Institute of Scientific and Technical Information of China (English)

    朱宪; 朱超; 赵亮; 程洪斌

    2008-01-01

    The hydrolysis technology and reaction kinetics for amino acids production from fish proteins in subcritical water reactor without catalysts were investigated in a reactor with volume of 400ml under the conditions of reaction temperature from 180-320℃, pressure from 5-26MPa, and time from 5-60min. The quality and quantity of amino acids in hydrolysate were determined by bioLiquid chromatography, and 17 kinds of amino acids were obtained. For the important 8 amino acids, the experiments were conducted to examine the effects of reaction temperature, pressure and time on amino acids yield. The optimum conditions for high yield are obtained from the experimental results. It is found that the nitrogen and carbon dioxide atmosphere should be used for leucine, isoleucine and histidine production while the air atmosphere might be used for other amino acids. The reaction time of 30min and the experimental temperature of 220℃, 240℃ and 260℃ were adopted for reaction kinetic research. The total yield of amino acids versus reaction time have been examined experimentally. According to these experimental data and under the condition of water excess, the macroscopic reaction kinetic equation of fish proteins hydrolysis was obtained with the hydrolysis reaction order of 1.615 and the rate constants being 0.0017, 0.0045 and 0.0097 at 220℃, 240℃ and 260℃ respectively. The activation energy is 145.1kJ·mol-1.

  9. Development of C-reactive protein certified reference material NMIJ CRM 6201-b: optimization of a hydrolysis process to improve the accuracy of amino acid analysis.

    Science.gov (United States)

    Kato, Megumi; Kinumi, Tomoya; Yoshioka, Mariko; Goto, Mari; Fujii, Shin-Ichiro; Takatsu, Akiko

    2015-04-01

    To standardize C-reactive protein (CRP) assays, the National Metrology Institute of Japan (NMIJ) has developed a C-reactive protein solution certified reference material, CRM 6201-b, which is intended for use as a primary reference material to enable the SI-traceable measurement of CRP. This study describes the development process of CRM 6201-b. As a candidate material of the CRM, recombinant human CRP solution was selected because of its higher purity and homogeneity than the purified material from human serum. Gel filtration chromatography was used to examine the homogeneity and stability of the present CRM. The total protein concentration of CRP in the present CRM was determined by amino acid analysis coupled to isotope-dilution mass spectrometry (IDMS-AAA). To improve the accuracy of IDMS-AAA, we optimized the hydrolysis process by examining the effect of parameters such as the volume of protein samples taken for hydrolysis, the procedure of sample preparation prior to the hydrolysis, hydrolysis temperature, and hydrolysis time. Under optimized conditions, we conducted two independent approaches in which the following independent hydrolysis and liquid chromatography-isotope dilution mass spectrometry (LC-IDMS) were combined: one was vapor-phase acid hydrolysis (130 °C, 24 h) and hydrophilic interaction liquid chromatography-mass spectrometry (HILIC-MS) method, and the other was microwave-assisted liquid-phase acid hydrolysis (150 °C, 3 h) and pre-column derivatization liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. The quantitative values of the two different amino acid analyses were in agreement within their uncertainties. The certified value was the weighted mean of the results of the two methods. Uncertainties from the value-assignment method, between-method variance, homogeneity, long-term stability, and short-term stability were taken into account in evaluating the uncertainty for a certified value. The certified value and the

  10. Distribution and Variation of Ribonucleic Acid (RNA) and Protein and Its Hydrolysis Products in Lake Sediments

    Institute of Scientific and Technical Information of China (English)

    梁小兵; 万国江; 黄荣贵

    2002-01-01

    Protein and RNA in lake sediments tend to be decomposed progressively with time and sedimentation depth. Their concentrations tend to decrease starting from the sedimentation depth of 17 cm and that of 19 cm, respectively. However, the products of their decomposition-amino acids and nucleotides show different rules of variation. At the depth from 27 cm to 30 cm the amino acids are most abundant in the pore waters of lake sediments. Such variation tendency seems to be related to the extent to which microbes utilize amino acids and nucleotides. Due to polymerization in the geological processes and the adsorption of protein on minerals and organic polymers, below the sedimentation depth of 17 cm there is still a certain amount of protein in the sediments. With the time passing by, protein has been well preserved in various sediment layers, indicating that its decomposition is relatively limited. The peak values of protein content in the sediments of the two lakes are produced in the surface layers at the depth of 10 cm, implicating that the surface sediments are favorable to the release of protein.The contents of amino acids in the pore waters of lake sediments are closely related to the activities of microbes. Below the depth of 27 cm, the amino acids are significantly accumulated in Lake Aha sediments, probably indicating the weakening of microbial activities.

  11. 肉苁蓉多糖水解产物单糖组分的气相色谱法测定%Determination of monosaccharides composition of Cistanche tubulosa polysaccharides by gas chromatography

    Institute of Scientific and Technical Information of China (English)

    王鑫彤; 张敏; 仰榴青; 王未; 吴慧玉; 汪松美; 刘红阳; 李倩; 贾清东; 张胜洋; 赵婷

    2016-01-01

    目的:研究气相色谱法测定肉苁蓉多糖中单糖组分的方法。方法:采用单因素实验,考察各因素对肉苁蓉多糖水解的影响;采用气相色谱法测定肉苁蓉多糖中的单糖组成。结果:肉苁蓉多糖水解的最佳条件为硫酸浓度3.0 mol/L,水解时间8 h和水解温度110℃;各单糖精密度RSD为0.92%~4.68%,重复性RSD为0.92%~1.77%,稳定性RSD为1.61%~3.61%,加样回收率为99.3%~100.3%,精密度、重复性、稳定性和回收率良好;肉苁蓉多糖主要由甘露糖、葡萄糖和半乳糖组成,摩尔比为2.01∶5.72∶2。结论:此法适用于肉苁蓉多糖中单糖组成分析。%Objective:To explore the optimal methods for analysis of the monosaccharides composition of Cistanche tubulosa polysaccharide.Methods:To investigate modifying factors of the polysaccharide hydroly-sis was determined by single factor method,and the monosaccharide composition analysis of Cistanche tubu-losa polysaccharide by gas chromatography.Results:The optimal hydrolysis conditions were sulfuric acid concentration 3.0 mol/L,hydrolysis time 8 h and temperature 1 10 ℃;the RSD value of precision was be-tween 0.92% and 4.68%,the RSD value of repeatability was between 0.92%and 1 .77%,the RSD value of stability was between 1.61% and 3.61%,the recovery rate were between 99.3% and 100.3%;Cistanche tubulosa polysaccharide was mainly composed of mannose,glucose and galactose in a molar ratio of 2.01 ∶5.72 ∶2.Conclusion:The refined method can be used for monosaccharides composition analy-sis of Cistanche tubulosa polysaccharides.

  12. 酸解木薯淀粉及其软糖性能研究%Study on properties of acid hydrolysis cassava starch and its jelly candy

    Institute of Scientific and Technical Information of China (English)

    范浩然; 熊柳; 孙庆杰

    2013-01-01

    The acid hydrolysis of cassava starches were prepared using cassava starch as material, treating starch with 6%HCl at 50℃for different durations(0 min,30 min,60 min,90 min). At the same time the acid hydrolysis of cassava starches were used to produce cassava starch jelly candy. The properties of the acid hydrolysis of cassava starch were investigated by determining the gelatinization and texture properties and assay the tensile properties and texture properties of the acid hydrolysis cassava starch jelly candy. The results showed that a significant decrease in starch viscosity and set back and an increase in hardness with increase in acid hydrolysis. The tensile properties of jelly candy with three different hydrolysis time all accord with industrial production index. The jelly candy with 60 min acid hydrolysis of cassava starch was better on hardness,adhesiveness,chewiness and resilience.%  以木薯淀粉为原料,在50℃下,用6%HCl对木薯淀粉进行不同时间(0 min、30 min、60 min、90 min)酸解改性,制备酸解木薯淀粉,并对酸解淀粉糊化特性和质构特性进行研究与分析;同时采用酸解木薯淀粉制备软糖,对制得酸解木薯淀粉软糖进行拉伸与质构分析.实验结果表明,随酸解时间增加;酸解木薯淀粉最低粘度、峰值粘度、回生值显著降低,淀粉凝胶硬度显著增加.3个不同水解时间木薯软糖拉伸率均符合工业生产指标,60 min酸解木薯淀粉制备软糖硬度适中,胶粘性、咀嚼性、回复性良好.

  13. Acid Pre hydrolysis of the Lignocellulose biomass from thistle Onopordum nervosum Boiss; Prehidrolisis acida de la Biomasa Lignocelulosica del Cardo Onopordum nervosum Boiss

    Energy Technology Data Exchange (ETDEWEB)

    Suarez Contreras, C.; Paz Saa, D.; Diaz Palma, A.

    1983-07-01

    The acid pre hydrolysis of the lignocellulose biomass from thistle O. nervosum has been conducted to determine the conditions for maximum yield of pentoses with minimum yield of hexoses. Variables studied were acid concentration (H{sub 2}SO{sub 4}, 1 , 3, 4 and 5%) , temperature (1000 and 120 degree centigree) time, solid to liquid ratio and degree of fineness of thistle (1 to 65 mesh). (Author) 15 refs.

  14. Hydrolysis of 4-Hydroxybenzoic Acid Esters (Parabens) and Their Aerobic Transformation into Phenol by the Resistant Enterobacter cloacae Strain EM

    Science.gov (United States)

    Valkova, Nelly; Lépine, François; Valeanu, Loredana; Dupont, Maryse; Labrie, Louisette; Bisaillon, Jean-Guy; Beaudet, Réjean; Shareck, François; Villemur, Richard

    2001-01-01

    Enterobacter cloacae strain EM was isolated from a commercial dietary mineral supplement stabilized by a mixture of methylparaben and propylparaben. It harbored a high-molecular-weight plasmid and was resistant to high concentrations of parabens. Strain EM was able to grow in liquid media containing similar amounts of parabens as found in the mineral supplement (1,700 and 180 mg of methyl and propylparaben, respectively, per liter or 11.2 and 1.0 mM) and in very high concentrations of methylparaben (3,000 mg liter−1, or 19.7 mM). This strain was able to hydrolyze approximately 500 mg of methyl-, ethyl-, or propylparaben liter−1 (3 mM) in less than 2 h in liquid culture, and the supernatant of a sonicated culture, after a 30-fold dilution, was able to hydrolyze 1,000 mg of methylparaben liter−1 (6.6 mM) in 15 min. The first step of paraben degradation was the hydrolysis of the ester bond to produce 4-hydroxybenzoic acid, followed by a decarboxylation step to produce phenol under aerobic conditions. The transformation of 4-hydroxybenzoic acid into phenol was stoichiometric. The conversion of approximately 500 mg of parabens liter−1 (3 mM) to phenol in liquid culture was completed within 5 h without significant hindrance to the growth of strain EM, while higher concentrations of parabens partially inhibited its growth. PMID:11375144

  15. Optimization of Two-Step Acid-Catalyzed Hydrolysis of Oil Palm Empty Fruit Bunch for High Sugar Concentration in Hydrolysate

    Directory of Open Access Journals (Sweden)

    Dongxu Zhang

    2014-01-01

    Full Text Available Getting high sugar concentrations in lignocellulosic biomass hydrolysate with reasonable yields of sugars is commercially attractive but very challenging. Two-step acid-catalyzed hydrolysis of oil palm empty fruit bunch (EFB was conducted to get high sugar concentrations in the hydrolysate. The biphasic kinetic model was used to guide the optimization of the first step dilute acid-catalyzed hydrolysis of EFB. A total sugar concentration of 83.0 g/L with a xylose concentration of 69.5 g/L and a xylose yield of 84.0% was experimentally achieved, which is in well agreement with the model predictions under optimal conditions (3% H2SO4 and 1.2% H3PO4, w/v, liquid to solid ratio 3 mL/g, 130°C, and 36 min. To further increase total sugar and xylose concentrations in hydrolysate, a second step hydrolysis was performed by adding fresh EFB to the hydrolysate at 130°C for 30 min, giving a total sugar concentration of 114.4 g/L with a xylose concentration of 93.5 g/L and a xylose yield of 56.5%. To the best of our knowledge, the total sugar and xylose concentrations are the highest among those ever reported for acid-catalyzed hydrolysis of lignocellulose.

  16. Mechanistic understanding of monosaccharide-air flow battery electrochemistry

    Science.gov (United States)

    Scott, Daniel M.; Tsang, Tsz Ho; Chetty, Leticia; Aloi, Sekotilani; Liaw, Bor Yann

    Recently, an inexpensive monosaccharide-air flow battery configuration has been demonstrated to utilize a strong base and a mediator redox dye to harness electrical power from the partial oxidation of glucose. Here the mechanistic understanding of glucose oxidation in this unique glucose-air power source is further explored by acid-base titration experiments, 13C NMR, and comparison of results from chemically different redox mediators (indigo carmine vs. methyl viologen) and sugars (fructose vs. glucose) via studies using electrochemical techniques. Titration results indicate that gluconic acid is the main product of the cell reaction, as supported by evidence in the 13C NMR spectra. Using indigo carmine as the mediator dye and fructose as the energy source, an abiotic cell configuration generates a power density of 1.66 mW cm -2, which is greater than that produced from glucose under similar conditions (ca. 1.28 mW cm -2). A faster transition from fructose into the ene-diol intermediate than from glucose likely contributed to this difference in power density.

  17. Effect of gamma Irradiation on the acidic hydrolysis of free-hemi cellulose thistle; Efecto de la irradiacion gamma en la hidrolisis acida de cardo exento de pentosas

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, C.; Paz, M. D.; Diaz, A.

    1983-07-01

    The effect of gamma-irradiation on the subsequent acidic hydrolysis of free-hemi cellulose Onopordum Nervosum Boiss thistle Ls determined. Its shown the influence of gamma-irradiation on the yield of sugar obtained flora the batch wise hydrol isis of the call ulose (1% H{sub 2}SO{sub 4} and 180 degree centigree at increasing doses). At all irradiation levels studied, the rate of hydrolysis of thistle samples was higher than the rate of hydrolysis of the cellulose from paper treated similarly. The maximum over-all yield of sugar in the irradiated lignocellulose material was about 66o at 100 MRad, less than two times the yield obtainable from the control. The corresponding yield from papel was 53%, 2'3 times that of the control. Irradiation under 1% H{sub 2}SO{sub 4} doesn't enhance the yield anyway. (Author) 21 refs.

  18. Nonfermentable, glucose-containing products formed from glucose under cellulose acid hydrolysis conditions

    Science.gov (United States)

    J. L. Minor

    1983-01-01

    Solutions of D-glucose in dilute sulfuric acid were allowed to react under time and temperature conditions which simulated the production of glucose from cellulose. Under these conditions, glucose undergoes a number of reactions including isomerization, dehydration, transglycosidation, polymerization, and anhydride formation. The specific interest in this report was to...

  19. Titan's Primordial Soup: Formation of Amino Acids via Low Temperature Hydrolysis of Tholins

    Science.gov (United States)

    Neish, Catherine; Somogyi, Á.; Smith, M. A.

    2009-09-01

    Titan, Saturn's largest moon, is a world rich in the "stuff of life". Reactions occurring in its dense nitrogen-methane atmosphere produce a wide variety of organic molecules, which subsequently rain down onto its surface. Water - thought to be another important ingredient for life - is likewise abundant on Titan. Theoretical models of Titan's formation predict that its interior consists of an ice I layer several tens of kilometers thick overlying a liquid ammonia-rich water layer several hundred kilometers thick (Tobie et al., 2005). Though its surface temperature of 94K dictates that Titan is on average too cold for liquid water to persist at its surface, melting caused by impacts and/or cryovolcanism may lead to its episodic availability. Impact melt pools on Titan would likely remain liquid for 102 - 104 years before freezing (O'Brien et al., 2005). The combination of complex organic molecules and transient locales of liquid water make Titan an interesting natural laboratory for studying prebiotic chemistry. In this work, we sought to determine what biomolecules might be formed under conditions analogous to those found in transient liquid water environments on Titan. We hydrolyzed Titan organic haze analogues, or "tholins", in 13 wt. % ammonia-water at 253K and 293K for a year. Using a combination of high resolution mass spectroscopy and tandem mass spectroscopy fragmentation techniques, four amino acids were identified in the hydrolyzed tholin sample. These four species have been assigned as the amino acids asparagine, aspartic acid, glutamine, and glutamic acid. This represents the first detection of biologically relevant molecules created under conditions similar to those found in impact melt pools and cryolavas on Titan. Future missions to Titan should therefore carry instrumentation capable of detecting amino acids and other prebiotically relevant molecules on its surface This work was supported by the NASA Exobiology Program.

  20. Influence of solid loading on D-xylose production through dilute sulphuric acid hydrolysis of olive stones

    Directory of Open Access Journals (Sweden)

    Cuevas, M.

    2015-09-01

    Full Text Available The selective hydrolysis of hemicellulose from olive stones was attempted in order to achieve a maximum D-xylose yield. For this aim, batch hydrolysis was conducted under different operating conditions of temperature, acid concentration and solid loading. Firstly, distilled water, sulphuric acid and nitric acid were assessed as hydrolytic agents at different temperatures (200, 205, 210 and 220 °C and at a fixed acid concentration (0.025 M. Sulphuric acid and 200 °C were selected for the subsequent dilute acid hydrolysis optimization based on the obtained D-xylose yields. The combined influence of solid loading (from 29.3 to 170.7 g olive stones into 300 mL acid solution and sulphuric acid concentration (0.006–0.034 M on the release of D-xylose was then estimated by response surface methodology. According to a statistical analysis, both parameters had significant interaction effects on D-xylose production. The results illustrated that the higher the solid loading, the higher the required acid concentration. The decrease in the solid/liquid ratio in the reactor had a positive effect on D-xylose extraction and on the amount of acid used. The optimum solid loading and sulphuric acid concentration were determined to be 50 g (solid/liquid ratio 1/6 and 0.016 M, respectively. Under these conditions, the predicted D-xylose yield (expressed as g of sugar per 100 g of dry matter fed was 20.4 (87.2% of maximum attainable.Se ha desarrollado una hidrólisis selectiva de la fracción hemicelulósica del hueso de aceituna con el fin de obtener el máximo rendimiento de D-xilosa. Para ello las hidrólisis se llevaron a cabo en un reactor discontinuo a distintas condiciones de temperatura, concentración de ácido y carga de sólidos. En primer lugar se evaluó la capacidad hidrolítica del agua destilada y de los ácidos nítrico y sulfúrico a distintas temperaturas (200, 205, 210 y 220°C manteniendo fija la concentración de ácido (0,025 M. A partir de

  1. Structures of polynuclear complexes of palladium(II) and platinum(II) formed by slow hydrolysis in acidic aqueous solution.

    Science.gov (United States)

    Torapava, Natallia; Elding, Lars I; Mändar, Hugo; Roosalu, Kaspar; Persson, Ingmar

    2013-06-07

    The aqua ions of palladium(II) and platinum(II) undergo extremely slow hydrolysis in strongly acidic aqueous solution, resulting in polynuclear complexes. The size and structures of these species have been determined by EXAFS and small angle X-ray scattering, SAXS. For palladium(II), the EXAFS data show that the Pd-O and Pd···Pd distances are identical to those of crystalline palladium(II) oxide, but the intensities of the Pd···Pd distances in the Fourier transform at 3.04 and 3.42 Å are significantly lower compared to those of crystalline PdO. Furthermore, no Pd···Pd distances beyond 4 Å are observed. These observations strongly indicate that the polynuclear palladium(II) complexes are oxido- and hydroxido-bridged species with the same core structure as solid palladium(II) oxide. Based on the number of Pd···Pd distances, as derived from the EXAFS data, their size can be estimated to be approximately two unit cells, or ca. 1.0 nm(3). For platinum(II), EXAFS data of the polynuclear species formed in the slow hydrolysis process show Pt-O and Pt···Pt distances identical to those of amorphous platinum(II) oxide, precipitating from the solution studied. The Pt···Pt distances are somewhat different from those reported for crystalline platinum(II) oxide. The polynuclear platinum(II) complexes have a similar structure to the palladium ones, but they are somewhat larger, with an estimated diameter of 1.5-3.0 nm. It has not been possible to precipitate any of these species by ultracentrifugation. They are detectable by SAXS, indicating diameters between 0.7 and 2 nm, in excellent agreement with the EXAFS observations. The number of oxido- relative to hydroxido bridges will increase with increasing size of the complex. The charge of the complexes will remain about the same, +4, at growth, with approximate formulas [Pd10O4(OH)8(H2O)12](4+) and [Pt14O8(OH)8(H2O)12](4+) for complexes with a size of 2 and 3 unit cells of the corresponding solid metal oxide

  2. Antioxidant activities of fucoidan degraded by gamma irradiation and acidic hydrolysis

    Science.gov (United States)

    Lim, Sangyong; Choi, Jong-il; Park, Hyun

    2015-04-01

    Low molecular weight fucoidan, prepared by radical degradation using gamma ray was investigated for its antioxidant activities with different assay methods. As the molecular weight of fucoidan decreased with a higher absorbed dose, ferric-reducing antioxidant power values increased, but β-carotene bleaching inhibition did not change significantly. The antioxidant activity of acid-degraded fucoidan was also examined to investigate the effect of different degradation methods. At the same molecular weight, fucoidan degraded by gamma irradiation showed higher 1,1-diphenyl-2-picrylhydrazyl radical scavenging activity than that observed with the acidic method. This result reveals that in addition to molecular weight, the degradation method affects the antioxidant activity of fucoidan.

  3. Spore Cortex Hydrolysis Precedes Dipicolinic Acid Release during Clostridium difficile Spore Germination

    OpenAIRE

    2015-01-01

    Bacterial spore germination is a process whereby a dormant spore returns to active, vegetative growth, and this process has largely been studied in the model organism Bacillus subtilis. In B. subtilis, the initiation of germinant receptor-mediated spore germination is divided into two genetically separable stages. Stage I is characterized by the release of dipicolinic acid (DPA) from the spore core. Stage II is characterized by cortex degradation, and stage II is activated by the DPA released...

  4. Physicochemical pretreatments and hydrolysis of furfural residues via carbon-based sulfonated solid acid.

    Science.gov (United States)

    Ma, Bao Jun; Sun, Yuan; Lin, Ke Ying; Li, Bing; Liu, Wan Yi

    2014-03-01

    Potential commercial physicochemical pretreatment methods, NaOH/microwave and NaOH/ultrasound were developed, and the carbon-based sulfonated solid acid catalysts were prepared for furfural residues conversion into reducing sugars. After the two optimum pretreatments, both the content of cellulose increased (74.03%, 72.28%, respectively) and the content of hemicellulose (94.11%, 94.17% of removal rate, respectively) and lignin (91.75%, 92.09% of removal rate, respectively) decreased in furfural residues. The reducing sugar yields of furfural residues with the two physicochemical pretreatments on coal tar-based solid acid reached 33.94% and 33.13%, respectively, higher than that pretreated via NaOH alone (27%) and comparable to that pretreated via NaOH/H2O2 (35.67%). The XRD patterns, IR spectra and SEM images show microwave and ultrasound improve the pretreatment effect. The results demonstrate the carbon-based sulfonated solid acids and the physicochemical pretreatments are green, effective, low-cost for furfural residues conversion.

  5. Study on preparation of ellagic acid by hydrolysis from pomegranate peel%水解法制备石榴皮鞣花酸工艺研究

    Institute of Scientific and Technical Information of China (English)

    杨笑笑; 邢晓平; 纪白慧; 卢婕; 曹玉华

    2013-01-01

    建立了以60%乙醇超声提取石榴皮粉末,粗提物经石油醚萃取除去脂溶性物质,乙酸乙酯萃取,萃取物用酸水解法水解制备鞣花酸的方法.采用超高效液相色谱-质谱法(UPLC-MS)确定了乙酸乙酯萃取部位的主要成分为粟木鞣花素、安石榴苷、石榴亭A、鞣料云石素、石榴亭B、鞣花酸,并鉴定酸水解产物为鞣花酸.采用毛细管电泳法(CE)监测了乙酸乙酯萃取物的酸水解历程,结果表明,随着水解时间的增加,乙酸乙酯萃取物的电泳峰不断减少,而水不溶物鞣花酸的质量不断增加.正交实验考察了水解时间、水解温度、酸浓度对鞣花酸得率的影响,最优水解条件为:水解时间6h、温度100℃、硫酸浓度1.0mol/L,鞣花酸得率达32.7%.%Preparation of ellagic acid from pomegranate peel by hydrolysis was developed.Pomegranate peel powder was extracted with 60% ethanol by means of ultrasonic-assisted extraction to obtain crude extract.After removal of lipophilic ingredients by extracting with petroleum ether,crude extract was extracted with ethyl acetate,and the ethyl acetate fraction was hydrolyzed to produce ellagic acid.With the ultra performance liquid chromatography-mass sPectrometry,the main ingredients in the ethyl acetate fraction were identified as castalagin,punicalagin,granatin A,corilagin,granatin B and ellagic acid,and the hydrolysis product was identified as ellagic acid.The hydrolysis process of the ethyl acetate fraction was monitored by capillary electrophoresis.It had been found that with the increase of hydrolysis time,the number of peaks in electropherogams was reduced,while the weight of ellagic acid increasing.With the orthogonal experiment,the influences of hydrolysis time,hydrolysis temperature,as well as acid concentration on the ellagic acid yield was investigated.It turned out that optimum conditions of hydrolysis were as follows:hydrolysis time of 6h,hydrolysis temperature at 100

  6. Monosaccharide composition analysis of immunomodulatory polysaccharides by on-line hollow fiber microextraction with high-performance liquid chromatography.

    Science.gov (United States)

    Wang, Nani; Wang, Xuping; Huang, Xiaowen; Mao, Zhujun; Zhang, Yang; Yu, Yong; Shou, Dan

    2016-03-01

    The monosaccharide compositions of functional polysaccharides are essential for structure elucidation and biological activity determination. A sensitive method based on on-line hollow-fiber liquid-phase microextraction with high-performance liquid chromatography has been established for the analysis of ten monosaccharide compositions (two uronic acids, two amino sugars and six neutral sugars) of the immunomodulatory polysaccharides. After derivatization, the sample was injected into the lumen of a hollow fiber immersed in butyl ether and separated by liquid chromatography. Under optimized conditions, the calibration curves were linear (r ≥ 0.9996) in the range of 10-2000 μmol L(-1) . The limits of detection were in the range of 0.04-1.58 μmol L(-1) , and the recoveries were in the range of 92.1-99.6%, which shows that the method is applicable to the analysis of the monosaccharide composition of various polysaccharides.

  7. Depolymerization of coal by O2 oxidation followed by acid hydrolysis; Sanso sanka-kasui bunkai ni yoru sekitan no teionkai jugo

    Energy Technology Data Exchange (ETDEWEB)

    Aizawa, S.; Hayashi, J.; Kumagai, H.; Chiba, T. [Hokkaido University, Sapporo (Japan). Center for Advanced Research of Energy Technology; Morooka, S. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

    1996-10-28

    With an objective to elucidate characteristics of oxygen addition to coal, and characteristics of solvent extraction by means of depolymerization, experiments were performed on oxygen oxidation and acid hydrolysis of brown coals. Coals used for the experiments are Morwell (MW), Yallourn (YL) , South Banko (SB) and Wyoming (WY) coals. Test samples were suspended in weak alkaline aqueous solution, and then oxygen was blown into them with pressure kept at atmospheric pressure. After a lapse of a predetermined time, the samples were cooled, and made as acidic as pH 1.3 in hydrochloric acid, followed by acid hydrolysis. Oxygen consumption increased with the reaction time, and with the MW coal, one mol oxygen reacted to 11 mols of coal. Spectral analysis on the YL and WY coal experiments revealed that aliphatic carbon combined with aromatic carbon or ether group has turned to peroxide, whose C-C or C-O bond was broken down as a result of acid hydrolysis of the peroxide, producing oxygen containing compounds. As a result of the depolymerization, the rate of extraction by using DMF, DMSO and methanol/THF mixed solvent increased to 90% or higher. Proportion of bond and cutting-off affects largely collapse of the cross-link structure. The carbon conversion to volatiles was at most 4%. 1 ref., 10 figs.

  8. Pretreatment of Dried Distiller Grains with Solubles by Soaking in Aqueous Ammonia and Subsequent Enzymatic/Dilute Acid Hydrolysis to Produce Fermentable Sugars.

    Science.gov (United States)

    Nghiem, Nhuan P; Montanti, Justin; Kim, Tae Hyun

    2016-05-01

    Dried distillers grains with solubles (DDGS), a co-product of corn ethanol production in the dry-grind process, was pretreated by soaking in aqueous ammonia (SAA) using a 15 % w/w NH4OH solution at a solid/liquid ratio of 1:10. The effect of pretreatment on subsequent enzymatic hydrolysis was studied at two temperatures (40 and 60 °C) and four reaction times (6, 12, 24, and 48 h). Highest glucose yield of 91 % theoretical was obtained for the DDGS pretreated at 60 °C and 24 h. The solubilized hemicellulose in the liquid fraction was further hydrolyzed with dilute H2SO4 to generate fermentable monomeric sugars. The conditions of acid hydrolysis included 1 and 4 wt% acid, 60 and 120 °C, and 0.5 and 1 h. Highest yields of xylose and arabinose were obtained at 4 wt% acid, 120 °C, and 1 h. The fermentability of the hydrolysate obtained by enzymatic hydrolysis of the SAA-pretreated DDGS was demonstrated in ethanol fermentation by Saccharomyces cerevisiae. The fermentability of the hydrolysate obtained by consecutive enzymatic and dilute acid hydrolysis was demonstrated using a succinic acid-producing microorganism, strain Escherichia coli AFP184. Under the fermentation conditions, complete utilization of glucose and arabinose was observed, whereas only 47 % of xylose was used. The succinic acid yield was 0.60 g/g total sugar consumed.

  9. Assessment of bioavailable organic phosphorus in tropical forest soils by organic acid extraction and phosphatase hydrolysis.

    Science.gov (United States)

    Darch, Tegan; Blackwell, Martin S A; Chadwick, David; Haygarth, Philip M; Hawkins, Jane M B; Turner, Benjamin L

    2016-12-15

    Soil organic phosphorus contributes to the nutrition of tropical trees, but is not accounted for in standard soil phosphorus tests. Plants and microbes can release organic anions to solubilize organic phosphorus from soil surfaces, and synthesize phosphatases to release inorganic phosphate from the solubilized compounds. We developed a procedure to estimate bioavailable organic phosphorus in tropical forest soils by simulating the secretion processes of organic acids and phosphatases. Five lowland tropical forest soils with contrasting properties (pH 4.4-6.1, total P 86-429 mg P kg(- 1)) were extracted with 2 mM citric acid (i.e., 10 μmol g(- 1), approximating rhizosphere concentrations) adjusted to soil pH in a 4:1 solution to soil ratio for 1 h. Three phosphatase enzymes were then added to the soil extract to determine the forms of hydrolysable organic phosphorus. Total phosphorus extracted by the procedure ranged between 3.22 and 8.06 mg P kg(- 1) (mean 5.55 ± 0.42 mg P kg(- 1)), of which on average three quarters was unreactive phosphorus (i.e., organic phosphorus plus inorganic polyphosphate). Of the enzyme-hydrolysable unreactive phosphorus, 28% was simple phosphomonoesters hydrolyzed by phosphomonoesterase from bovine intestinal mucosa, a further 18% was phosphodiesters hydrolyzed by a combination of nuclease from Penicillium citrinum and phosphomonoesterase, and the remaining 51% was hydrolyzed by a broad-spectrum phytase from wheat. We conclude that soil organic phosphorus can be solubilized and hydrolyzed by a combination of organic acids and phosphatase enzymes in lowland tropical forest soils, indicating that this pathway could make a significant contribution to biological phosphorus acquisition in tropical forests. Furthermore, we have developed a method that can be used to assess the bioavailability of this soil organic phosphorus.

  10. Purification and characterization of a chlorogenic acid hydrolase from Aspergillus niger catalysing the hydrolysis of chlorogenic acid.

    Science.gov (United States)

    Asther, Michèle; Estrada Alvarado, Maria Isabel; Haon, Mireille; Navarro, David; Asther, Marcel; Lesage-Meessen, Laurence; Record, Eric

    2005-01-12

    Among 15 Aspergillus strains, Aspergillus niger BRFM 131 was selected for its high chlorogenic acid hydrolase activity. The enzyme was purified and characterized with respect to its physico-chemical and kinetic properties. Four chromatographic steps were necessary to purify the protein to homogeneity with a recovery of 2%. Km of the chlorogenic acid hydrolase was estimated to be 10 microM against chlorogenic acid as substrate. Under native conditions, the protein presented a molecular mass of 170 kDa, and SDS-PAGE analysis suggested the presence of two identical 80 kDa subunits. Isoelectric point was 6.0; pH optimum for activity was determined to be 6.0 and temperature optima to be 55 degrees C. The N-terminal sequence did not present any homology with other cinnamoyl ester hydrolases previously described suggesting the purification of a new protein. The chlorogenic acid hydrolase was used successfully for the production of caffeic acid, which possesses strong antioxidant properties, from natural substrates specially rich in chlorogenic acid like apple marc and coffee pulp.

  11. Synergy of Lewis and Brønsted acids on catalytic hydrothermal decomposition of carbohydrates and corncob acid hydrolysis residues to 5-hydroxymethylfurfural.

    Science.gov (United States)

    Wang, Chao; Zhang, Liming; Zhou, Tian; Chen, Jiachuan; Xu, Feng

    2017-01-13

    5-hydroxymethylfurfural (HMF) is an important platform molecule in the synthesis of various chemicals and materials. Herein, we reported a simple and effective dehydration of glucose-based carbohydrates to HMF in a biphasic system containing cyclopentyl methyl ether as the organic phase and AlCl3 with minute amounts of HCl as co-catalysts. The results showed that the mixed catalysts had a positive synergistic catalytic effect on glucose conversion to HMF compared with single AlCl3 or HCl catalyst. For glucose, the highest HMF yield of 54.5% was achieved at 175 °C for 20 min. More importantly, the optimal catalytic system was so efficient that it achieved one of the highest reported yields of HMF (30.5%) directly from corncob acid hydrolysis residues. Thus, the catalytic system can become a promising route for effective utilization of biomass in future biorefineries.

  12. Influence of lactose hydrolysis and solids concentration on alcohol production by yeast in acid whey ultrafiltrate

    Energy Technology Data Exchange (ETDEWEB)

    O' leary, V.S.; Sutton, C.; Bencivengo, M.; Sullivan, B.; Holsinger, V.H.

    1977-11-01

    Alcohol yields of 6.5 percent were obtained with Saccharomyces cerevisiae in lactase-hydrolyzed acid whey permeate containing 30 to 35 percent total solids. Maximum alcohol yields obtained with Kluyveromyces fragilis were 4.5 percent in lactase-hydrolyzed acid whey permeate at a solids concentration of 20 percent and 3.7 percent in normal permeate at a solids concentration of 10 percent. Saccharomyces cerevisiae efficiently converted the glucose present in lactase-hydrolyzed whey permeates containing 5 to 30 percent total solids (2 to 13 percent glucose) to alcohol. However, the galactose, which comprised about half the available carbohydrate in lactase-hydrolyzed whey, was not utilized by S. cerevisiae, so that even though alcohol yields were higher when this organism was used, the process was wasteful in that a substantial proportion of the substrate was not fermented. For the process to become commercially feasible, an efficient means of rapidly converting both the galactose and glucose to alcohol must be found.

  13. Acid hydrolysis of wheat gluten induces formation of new epitopes but does not enhance sensitizing capacity by the oral route: a study in "gluten free" Brown Norway rats.

    Science.gov (United States)

    Kroghsbo, Stine; Andersen, Nanna B; Rasmussen, Tina F; Jacobsen, Susanne; Madsen, Charlotte B

    2014-01-01

    Acid hydrolyzed wheat proteins (HWPs) are used in the food and cosmetic industry as emulsifiers. Cases of severe food allergic reactions caused by HWPs have been reported. Recent data suggest that these reactions are caused by HWPs produced by acid hydrolysis. To examine the sensitizing capacity of gluten proteins per se when altered by acid or enzymatic hydrolysis relative to unmodified gluten in rats naïve to gluten. High IgE-responder Brown Norway (BN) rats bred on a gluten-free diet were sensitized without the use of adjuvant to three different gluten products (unmodified, acid hydrolyzed and enzymatic hydrolyzed). Rats were sensitized by intraperitoneal (i.p.) immunization three times with 200 µg gluten protein/rat or by oral dosing for 35 days with 0.2, 2 or 20 mg gluten protein/rat/day. Sera were analyzed for specific IgG and IgE and IgG-binding capacity by ELISA. IgE functionality was measured by rat basophilic leukemia (RBL) assay. Regardless of the route of dosing, all products had sensitizing capacity. When sensitized i.p., all three gluten products induced a strong IgG1 response in all animals. Acid hydrolyzed gluten induced the highest level of specific IgE but with a low functionality. Orally all three gluten products induced specific IgG1 and IgE but with different dose-response relations. Sensitizing rats i.p. or orally with unmodified or enzymatic hydrolyzed gluten induced specific IgG1 responses with similar binding capacity which was different from that of acid hydrolyzed gluten indicating that acid hydrolysis of gluten proteins induces formation of 'new' epitopes. In rats not tolerant to gluten acid hydrolysis of gluten enhances the sensitizing capacity by the i.p. but not by the oral route. In addition, acid hydrolysis induces formation of new epitopes. This is in contrast to the enzymatic hydrolyzed gluten having an epitope pattern similar to unmodified gluten.

  14. Acid hydrolysis of wheat gluten induces formation of new epitopes but does not enhance sensitizing capacity by the oral route: a study in "gluten free" Brown Norway rats.

    Directory of Open Access Journals (Sweden)

    Stine Kroghsbo

    Full Text Available Acid hydrolyzed wheat proteins (HWPs are used in the food and cosmetic industry as emulsifiers. Cases of severe food allergic reactions caused by HWPs have been reported. Recent data suggest that these reactions are caused by HWPs produced by acid hydrolysis.To examine the sensitizing capacity of gluten proteins per se when altered by acid or enzymatic hydrolysis relative to unmodified gluten in rats naïve to gluten.High IgE-responder Brown Norway (BN rats bred on a gluten-free diet were sensitized without the use of adjuvant to three different gluten products (unmodified, acid hydrolyzed and enzymatic hydrolyzed. Rats were sensitized by intraperitoneal (i.p. immunization three times with 200 µg gluten protein/rat or by oral dosing for 35 days with 0.2, 2 or 20 mg gluten protein/rat/day. Sera were analyzed for specific IgG and IgE and IgG-binding capacity by ELISA. IgE functionality was measured by rat basophilic leukemia (RBL assay.Regardless of the route of dosing, all products had sensitizing capacity. When sensitized i.p., all three gluten products induced a strong IgG1 response in all animals. Acid hydrolyzed gluten induced the highest level of specific IgE but with a low functionality. Orally all three gluten products induced specific IgG1 and IgE but with different dose-response relations. Sensitizing rats i.p. or orally with unmodified or enzymatic hydrolyzed gluten induced specific IgG1 responses with similar binding capacity which was different from that of acid hydrolyzed gluten indicating that acid hydrolysis of gluten proteins induces formation of 'new' epitopes.In rats not tolerant to gluten acid hydrolysis of gluten enhances the sensitizing capacity by the i.p. but not by the oral route. In addition, acid hydrolysis induces formation of new epitopes. This is in contrast to the enzymatic hydrolyzed gluten having an epitope pattern similar to unmodified gluten.

  15. Enhancing bio-butanol production from biomass of Chlorella vulgaris JSC-6 with sequential alkali pretreatment and acid hydrolysis.

    Science.gov (United States)

    Wang, Yue; Guo, Wanqian; Cheng, Chieh-Lun; Ho, Shih-Hsin; Chang, Jo-Shu; Ren, Nanqi

    2016-01-01

    This study presents a successful butanol production method using alkali and acid pretreated biomass of Chlorella vulgaris JSC-6. The butanol concentration, yield, and productivity were 13.1g/L, 0.58mol/mol sugar, 0.66g/L/h, respectively. Nearly 2.93L/L of biohydrogen was produced during the acidogenesis phase in ABE fermentation. The hydrogen yield and productivity were 0.39mol/mol sugar and 104.2g/L/h respectively. In addition, the high glucose consumption efficiency (97.5%) suggests that the hydrolysate pretreated with NaOH (1%) followed by H2SO4 (3%) did not contain inhibitors to the fermentation. It was also discovered that an excess amount of nitrogen sources arising from hydrolysis of highly concentrated microalgal biomass negatively affected the butanol production. This work demonstrates the technical feasibility of producing butanol from sustainable third-generation feedstock (i.e., microalgal biomass).

  16. Relationship between stimulated phosphatidic acid production and inositol lipid hydrolysis in intestinal longitudinal smooth muscle from guinea pig.

    Science.gov (United States)

    Mallows, R S; Bolton, T B

    1987-06-15

    Accumulation of [32P]phosphatidic acid (PA) and total [3H]inositol phosphates (IPs) was measured in the longitudinal smooth-muscle layer from guinea-pig small intestine. Stimulation with carbachol, histamine and substance P produced increases in accumulation of both [3H]IPs and [32P]PA over the same concentration range. The increase in [32P]PA accumulation in response to carbachol (1 microM-0.1 mM) was inhibited in the presence of atropine (0.5 microM). Buffering the external free [Ca2+] to 10 nM did not prevent the carbachol-stimulated increase in [32P]PA accumulation. Carbachol and Ca2+ appear to act synergistically to increase accumulation of [32P]PA. In contrast, although incubation with noradrenaline also increased accumulation of [3H]IPs, no increase in accumulation of [32P]PA could be detected. These results suggest that an increase in formation of IPs is not necessarily accompanied by an increase in PA formation, and imply the existence of receptor-modulated pathways regulating PA concentrations other than by phospholipase-C-catalysed inositol phospholipid hydrolysis.

  17. Deuterium isotope effects on acid ionization and transition metal hydrolysis at reactor conditions by Raman spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Yacyshyn, M.; Madekufamba, M.; Tremaine, P. [Univ. of Guelph, Dept. of Chemistry, Guelph, Ontario (Canada)

    2011-07-01

    This paper reports the preliminary measurements from an experimental study to measure the small differences between light (H{sub 2}O) and heavy (D{sub 2}O) water under reactor operating conditions (250-300 {sup o}C, 10 MPa), using Raman spectroscopy. The deuterium isotope effect δpK = pK{sub D2O} - pK{sub H2O}, for sodium bisulphate NaDSO{sub 4} and phosphoric acid D{sub 3}PO{sub 4}, has now been determined at temperatures of 25 {sup o}C and 80 {sup o}C by measuring the isotropic Raman spectra at different concentrations. The results for the pK and ΔpK at 25 {sup o}C agree with the literature, confirming the reliability of the method. High temperature cells have been constructed. (author)

  18. 碱法水解油菜籽油制备脂肪酸%Research on the Production of the Fatty Acid from Rapeseed Oil with Alkali Hydrolysis

    Institute of Scientific and Technical Information of China (English)

    罗庆华; 林俊清; 张习敏

    2011-01-01

    [目的]研究碱法水解植物油脂的游离脂肪酸得率,为生物柴油的工业化生产提供科学数据.[方法]以油菜籽油为试验材料,研究碱法制备脂肪酸过程中NaOH浓度、反应时间和工艺条件对油菜籽油脂水解的效果.[结果]增加NaOH浓度和延长反应时间均可以提高水解率.最佳反应条件为两步法水解:先用23.5%NaOH水解3 h、然后用11.75%NaOH水解2 h.此条件下油菜籽油的水解率可达99.64%.[结论]采用两步法碱法分解油菜籽油效果理想.%[ Objective ] The scientific data of the industrial production of biological diesel was provided through the research on the efficiency of the fatty acid isolated from plant oil with the method of alkali hydrolysis. [ Method ] The effect of the concentration of NaOH, reaction time and processing technology on the hydrolysis of rapeseed oil in the production of the fatty acid isolated from plant oil with the method of alkali hydrolysis was experimented. [ Results] The result showed that hydrolysis rate of rapeseed oil could be raised with the concentration-increasing of NaOH and the reaction time-prolonging. The optimal measure of it was two-step hydrolysis method. The first step was the raw material was hydrolyzed by 23.5% NaOH for 3 hours, and then, by 11.75% NaOH for 2 hours, under which measure, the hydrolysis rate reached at 99.64%. [ Conclusion] The idea efficiency of the fatty acid isolated from rapeseed oil was two-step hydrolysis method.

  19. Effect of Acid Hydrolysis Conditions on the Properties of Cellulose Nanoparticle-Reinforced Polymethylmethacrylate Composites

    Directory of Open Access Journals (Sweden)

    Guangping Han

    2013-12-01

    Full Text Available Cellulose nanoparticles (CNPs were prepared from microcrystalline cellulose using two concentration levels of sulfuric acid (i.e., 48 wt% and 64 wt% with produced CNPs designated as CNPs-48 and CNPs-64, respectively followed by high-pressure homogenization. CNP-reinforced polymethylmethacrylate (PMMA composite films at various CNP loadings were made using solvent exchange and solution casting methods. The ultraviolet-visible (UV-vis transmittance spectra between 400 and 800 nm showed that CNPs-64/PMMA composites had a significantly higher optical transmittance than that of CNPs-48/PMMA. Their transmittance decreased with increased CNP loadings. The addition of CNPs to the PMMA matrix reduced composite’s coefficient of thermal expansion (CTE, and CNPs-64/PMMA had a lower CTE than CNPs-48/PMMA at the same CNP level. Reinforcement effect was achieved with the addition of CNPs to the PMMA matrix, especially at higher temperature levels. CNPs-64/PMMA exhibited a higher storage modulus compared with CNPs-48/PMMA material. All CNP-reinforced composites showed higher Young’s modulus and tensile strengths than pure PMMA. The effect increased with increased CNP loadings in the PMMA matrix for both CNPs-64/PMMA and CNPs-48/PMMA composites. CNPs affected the Young’s modulus more than they affected the tensile strength.

  20. Surface lignin change pertaining to the integrated process of dilute acid pre-extraction and mechanical refining of poplar wood chips and its impact on enzymatic hydrolysis.

    Science.gov (United States)

    Liu, Wei; Chen, Wei; Hou, Qingxi; Zhang, Jinping; Wang, Bing

    2017-03-01

    Dilute acid pre-extraction enhanced the mechanically refined poplar pulp substrates' enzymatic hydrolysis efficiency obviously. The results showed that the surface lignin distribution was changed significantly in residual wood chips and pulp substrates, and the surface lignin distribution showed important impact on the following enzymatic hydrolysis. Acid pre-extraction can lead to a redistribution of lignin in fiber cell walls, i.e., the lignin was degraded and migrated to fiber surface in the form of re-deposited lignin and pseudo-lignin. However, higher pre-extraction intensity was not desired due to the formation of redeposited lignin and pseudo-lignin. This study will help to reach a deeper understanding on the lignin distribution in the view of molecular and ultrastructure, and promote the development of a cost-efficient pretreatment strategy for biomass processing.

  1. Purification and characterization of a gentiohexaose obtained from botryosphaeran by partial acid hydrolysis; Purificacao e caracterizacao de uma gentioexaose obtida de botriosferana por hidrolise acida parcial

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Iara Ribeiro; Monteiro, Nilson Kobori; Martinez, Paula Felippe; Izeli, Nataly Lino; Vasconcelos, Ana Flora Dalberto; Cardoso, Marilsa de Stefani; Silva, Maria de Lourdes Corradi da [UNESP, Presidente Prudente, SP (Brazil). Faculdade de Ciencias e Tecnologia. Dept. de Fisica, Quimica e Biologia]. E-mail: corradi@fct.unesp.br; Barbosa, Aneli de Melo [Universidade Estadual de Londrina (UEL), PR (Brazil). Dept. de Bioquimica e Biotecnologia; Dekker, Robert F.H. [Universidad de Castilla-La Mancha-IRICA, Ciudad Real (Spain); Silva, Gil Valdo Jose da; Moraes, Luis Alberto Beraldo de [Universidade de Sao Paulo (USP), Ribeirao Preto, SP (Brazil). Faculdade de Filosofia, Ciencias e Letras. Dept. de Quimica

    2008-07-01

    A hexa-oligosaccharide was obtained by partial acid hydrolysis from botryosphaeran, an exopolysaccharide (EPS) {beta}(1{yields}3; 1{yields}6)-D-glucan type, produced by the ascomyceteous fungus Botryosphaeria rhodina. The oligosaccharide was purified by gel filtration and charcoal-Celite column chromatography and the analysis was followed by HPAEC/ PAD. The structure was determined by NMR spectroscopy and mass spectrometry, which showed that the oligosaccharide consists of six {beta}-D-glucopyranosyl units O-6 substituted (gentiohexaose). (author)

  2. Summary Report on Gamma Radiolysis of TBP/n-dodecane in the Presence of Nitric Acid Using the Radiolysis/Hydrolysis Test Loop

    Energy Technology Data Exchange (ETDEWEB)

    Dean R. Peterman; Bruce J. Mincher; Catherine L. Riddle; Richard D. Tillotson

    2010-08-01

    Design and installation has been completed for a state-of-the-art radiolysis/hydrolysis test loop system. The system is used to evaluate the effects of gamma radiolysis and acid hydrolysis on the stability and performance of solvent extraction process solvents. The test loop is comprised of two main sections; the solvent irradiation and hydrolysis loop and the solvent reconditioning loop. In the solvent irradiation and hydrolysis loop, aqueous and organic phases are mixed and circulated through a gamma irradiator until the desired absorbed dose is achieved. Irradiation of the mixed phases is more representative of actual conditions in a solvent extraction process. Additionally, the contact of the organic phase with the aqueous phase will subject the solvent components to hydrolysis. This hydrolysis can be accelerated by controlling the system at an elevated temperature. At defined intervals, the organic from the irradiation/hydrolysis loop will be transferred to the solvent reconditioning loop where the solvent is contacted with scrub, strip, and solvent wash solutions which simulate process flowsheet conditions. These two processes are repeated until the total desired dose is achieved. Since all viable solvent extraction components in an advanced fuel cycle must exhibit high radiolytic and hydrolytic stability, this test loop is not limited to any one solvent system but is applicable to all systems of interest. Also, the test loop is not limited to testing of process flowsheets. It is also a valuable tool in support of fundamental research on newly identified extractants/modifiers and the impact of gamma radiation on their stability in a dynamic environment. The investigation of the radiolysis of a TBP/n-dodecane process solvent in contact with aqueous nitric acid has been performed. These studies were intended to confirm/optimize the operability of the test loop system. Additionally, these data are directly applicable to numerous other solvent extraction

  3. A new effective process for production of curdlan oligosaccharides based on alkali-neutralization treatment and acid hydrolysis of curdlan particles in water suspension.

    Science.gov (United States)

    Li, Jing; Zhu, Li; Zheng, Zhi-Yong; Zhan, Xiao-Bei; Lin, Chi-Chung; Zong, Yu; Li, Wei-Jiang

    2013-10-01

    Biologically active β-1,3-oligosaccharides with rapidly growing biomedical applications are produced from hydrolysis of curdlan polysaccharide. The water-insoluble curdlan impedes its hydrolysis efficiency which is enhanced by our newly developed alkali-neutralization treatment process to increase the stability of curdlan suspension to more than 20 days, while the untreated control settled within 5 min. A putative double-layer structure model comprising of a compact core and a hydrated outer layer was proposed to describe the treated curdlan particles based on sedimentation and scanning electron microscopy observation. This model was verified by single- and two-step acid hydrolysis, indicative of the reduced susceptibility to hydrolysis when close to the compact core. Electrospray ionization-mass spectrometry, thin-layer chromatography analyses, and effective HPLC procedure led to the development of improved process to produce purified individual β-1,3-oligosaccharides with degrees of polymerization from 2 to 10 and potential for biomedical applications from curdlan hydrolyzate. Our new curdlan oligosaccharide production process offers an even better alternative to the previously published processes.

  4. Monosaccharides as Versatile Units for Water-Soluble Supramolecular Polymers.

    Science.gov (United States)

    Leenders, Christianus M A; Jansen, Gijs; Frissen, Martijn M M; Lafleur, René P M; Voets, Ilja K; Palmans, Anja R A; Meijer, E W

    2016-03-18

    We introduce monosaccharides as versatile water-soluble units to compatibilise supramolecular polymers based on the benzene-1,3,5-tricarboxamide (BTA) moiety with water. A library of monosaccharide-based BTAs is evaluated, varying the length of the alkyl chain (hexyl, octyl, decyl and dodecyl) separating the BTA and saccharide units, as well as the saccharide units (α-glucose, β-glucose, α-mannose and α-galactose). In all cases, the monosaccharides impart excellent water compatibility. The length of the alkyl chain is the determining factor to obtain either long, one-dimensional supramolecular polymers (dodecyl spacer), small aggregates (decyl spacer) or molecularly dissolved (octyl and hexyl) BTAs in water. For the BTAs comprising a dodecyl spacer, our results suggest that a cooperative self-assembly process is operative and that the introduction of different monosaccharides does not significantly change the self- assembly behaviour. Finally, we investigate the potential of post-assembly functionalisation of the formed supramolecular polymers by taking advantage of dynamic covalent bond formation between the monosaccharides and benzoxaboroles. We observe that the supramolecular polymers readily react with a fluorescent benzoxaborole derivative permitting imaging of these dynamic complexes by confocal fluorescence microscopy.

  5. Hydrolysis of cellooligosaccharides catalyzed by organic acid%有机酸催化水解纤维低聚糖的研究

    Institute of Scientific and Technical Information of China (English)

    马淑玲; 彭红

    2014-01-01

    The order of catalytic activity of organic acids for hydrolysis of cellooligosaccharides is oxalic acid>maleic acid>malonic acid>acetic acid>formic acid>butanedioic acid. Butanedioic acid could not catalyze the hydrolysis of cellooligosaccharides. The catalytic activity of biatomic acids is relative to their acidity. The acid with higher acidity resulted in higher conversion of cellooligosaccharides. The hydrolysis of cellooligosaccharides catalyzed by organic acid processed step by step,glucose and cellooligosaccharides with lower degree of polymerization produced first,and the produced oligosaccharides was hydrolyzed further. When cellotriose,cellotetraose,and cellopentaose were hydrolyzed under the conditions of substrate concentration 1.5 mg/mL,oxalic acid dosage 0.05 mmol/mL,reaction time 9 h,and temperature 95℃,the product concentrations of glucose were 0.51, 0.53,and 0.13 mg/mL respectively.%有机酸催化水解纤维低聚糖的能力强弱顺序为:草酸>顺丁烯二酸>丙二酸>乙酸>甲酸>丁二酸,丁二酸不能催化水解纤维低聚糖。二元羧酸水解纤维低聚糖时的能力与其水溶液酸性强弱有关,酸性越强,催化水解能力越大,低聚糖的水解率高。有机酸水解纤维低聚糖是分步进行的,先生成葡萄糖和低一级的低聚糖,低一级的低聚糖再水解生成葡萄糖和更低一级的低聚糖。在初始低聚糖浓度为1.5 mg/mL、水解时间9 h和水解温度95℃的条件下,0.05 mmol/mL草酸分别催化水解纤维三糖、纤维四糖和纤维五糖后产物葡萄糖浓度分别为0.51、0.53和0.13 mg/mL。

  6. Comparison of polysaccharides of Haliotis discus hannai and Volutharpa ampullacea perryi by PMP-HPLC-MS(n) analysis upon acid hydrolysis.

    Science.gov (United States)

    Wang, Hongxu; Zhao, Jun; Li, Dongmei; Wen, Chengrong; Liu, Haiman; Song, Shuang; Zhu, Beiwei

    2015-10-13

    Haliotis discus hannai Ino (Haliotis) is a highly valued marine shellfish, and it is sometimes replaced by another cheaper Gastropoda mollusk, Volutharpa ampullacea perryi (Volutharpa). Polysaccharides from pleopods, viscera and gonads of these two gastropods were compared by analyzing the mono- and di-saccharides in their acid hydrolysates using high performance liquid chromatography-mass spectrometry (HPLC-MS(n)) after 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatization. Disaccharide analysis revealed the distribution of uronic acid-containing polysaccharides (UACPs) in the biological samples. GlcA-(1 → 2)-Man, GlcA-(1 → 3)-GalN, and another disaccharide consisting of a hexuronic acid linked to a hexose were found in the hydrolysates, which indicated the existence of AGSP (abalone gonad sulfated polysaccharide) with the backbone composed of → 2)-α-Man(1 → 4)-β-GlcA(1 → repeating unit, AAP (abalone glycosaminoglycan-like polysaccharide) with the backbone of → 3)-GalNAc-(1 → 2)-GlcA-(1 → 3)-GalNAc-(1 → 4)-GlcA-(1 → repeating unit, and unidentified DS1P containing a hexuronic acid linked to a hexose unit, respectively. As shown by extracted ion chromatograms (XICs), AAP was the only UACP found in pleopods of the two gastropods; gonads and viscera of Haliotis contained DS1P and AGSP, while those of Volutharpa contained DS1P, AGSP as well as AAP. Monosaccharides in the acid hydrolysates were demonstrated in XICs by extracting their corresponding PMP derivative quasi-molecular ions one by one, and the results indicated the similar conclusion to the disaccharide analysis. Therefore, it could be concluded that polysaccharides from pleopods of the two gastropods are very similar, while those from their viscera and gonads differ greatly.

  7. [Principles of the hydrolysis of bound purine and pyrimidine bases in foods and program-controlled calculation of nucleic acid content].

    Science.gov (United States)

    Herbel, W; Montag, A

    1987-01-01

    In order to determine the amount of combined purine and pyrimidine bases in foods we investigated the chemical fundamentals of their hydrolytic digestion it was demonstrated that the digestion mixture used, containing trifluoracetic- and formic acids, protected the purine bases during hydrolysis from oxidative degradation due to carbon monoxide formation. Further, a time-saving computer-program was developed and presented. This program allows, depending on the purine composition, the calculation of the corresponding nucleic acids, the nucleotides and the purine-nitrogen-content of the food.

  8. Characterization of Firing Range Soil from Camp Edwards, MA, and the Efficacy of Acid and Alkaline Hydrolysis for the Remediation of M1 105mm M67 Propellant

    Science.gov (United States)

    2013-06-01

    using 3/4–in. AMS butyrate plastic soil recovery liners (Forestry Supply, Jackson, MS). The subsamples were well mixed, yielding a representative...ER D C/ EL T R -1 3 -1 0 Characterization of Firing Range Soil from Camp Edwards, MA, and the Efficacy of Acid and Alkaline Hydrolysis...acwc.sdp.sirsi.net/client/default. ERDC/EL TR-13-10 June 2013 Characterization of Firing Range Soil from Camp Edwards, MA, and the Efficacy of Acid and

  9. Monosaccharide composition of glycans based on Q-HSQC NMR.

    Science.gov (United States)

    Sassaki, Guilherme Lanzi; Guerrini, Marco; Serrato, Rodrigo Vassoler; Santana Filho, Arquimedes Paixão; Carlotto, Juliane; Simas-Tosin, Fernanda; Cipriani, Thales Ricardo; Iacomini, Marcello; Torri, Giangiacomo; Gorin, Philip Albert James

    2014-04-15

    Glycans have essential functions related to structural architecture and specific cell surface phenomena, such as differentiation, biosignalling, recognition and cell-cell interaction, with the carbohydrate structure determining main function in the cell. Due to the importance of the primary structure, the monosaccharide composition is crucial to show the glycan structure. We now present a method for complex carbohydrates based on NMR spectroscopy, which has shown to give similar results to those obtained by the classic GC-MS-carboxy-reduction/deuterium labeling approach. Quantitative HSQC, through JCH dependence showed 155 Hz as the best value for (1)H/(13)C anomeric aldoses, allowing milli-microM detection using conventional inverse probe heads. Combining the quantification of native monosaccharide units of the glycan and those from the hydrolyzed product, a strong correlation occurs between the molecular mobility of the monosaccharide units, giving rise to some insights on the dynamic properties of the parent glycan.

  10. Enzymic lactose hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Miller, J.J.; Brand, J.C.

    1980-01-01

    Acid or enzymic hydrolysis can be used to hydrolyze lactose. Advantages of both are compared and details of enzymic hydrolysis using yeast or fungal enzymes given. The new scheme outlined involves recycling lactase. Because lactose and lactase react to ultrafiltration (UF) membranes differently separation is possible. Milk or milk products are ultrafiltered to separate a concentrate from a lactose-rich permeate which is treated with lactase in a reactor until hydrolysis reaches a required level. The lactase can be removed by UF as it does not permeate the membrane, and it is recycled back to the reactor. Permeate from the second UF stage may or may not be recombined with the concentrate from the first stage to produce a low lactose product (analysis of a typical low-lactose dried whole milk is given). Batch or continuous processes are explained and a batch process without enzyme recovery is discussed. (Refs. 4).

  11. Evaluation of the Fermentation Potential of Pulp Mill Residue to Produce D(-)-Lactic Acid by Separate Hydrolysis and Fermentation Using Lactobacillus coryniformis subsp. torquens.

    Science.gov (United States)

    de Oliveira Moraes, Anelize; Ramirez, Ninoska Isabel Bojorge; Pereira, Nei

    2016-12-01

    Lactic acid is widely used in chemical, pharmaceutical, cosmetic, and food industries, besides it is the building block to produce polylactic acid, which is a sustainable alternative biopolymer to synthetic plastic due to its biodegradability. Aiming at producing an optically pure isomer, the present work evaluated the potential of pulp mill residue as feedstock to produce D(-)-lactic acid by a strain of the bacterium Lactobacillus coryniformis subsp. torquens using separate hydrolysis and fermentation process. Enzymatic hydrolysis, optimized through response surface methodology for 1 g:4 mL solid/liquid ratio and 24.8 FPU/gcellulose enzyme loading, resulted in 140 g L(-1) total reducing sugar and 110 g L(-1) glucose after 48 h, leading to 61 % of efficiency. In instrumented bioreactor, 57 g L(-1) of D(-)-lactic acid was achieved in 20 h of fermentation, while only 0.5 g L(-1) of L(+)-lactic acid was generated. Furthermore, product yield of 0.97 g/g and volumetric productivity of 2.8 g L(-1) h(-1) were obtained.

  12. Effect of pretreatment severity on accumulation of major degradation products from dilute acid pretreated corn stover and subsequent inhibition of enzymatic hydrolysis of cellulose.

    Science.gov (United States)

    Um, Byung-Hwan; van Walsum, G Peter

    2012-09-01

    The concept of reaction severity, which combines residence time and temperature, is often used in the pulp and paper and biorefining industries. The influence of corn stover pretreatment severity on yield of sugar and major degradation products and subsequent effects on enzymatic cellulose hydrolysis was investigated. The pretreatment residence time and temperature, combined into the severity factor (Log R(o)), were varied with constant acid concentration. With increasing severity, increasing concentrations of furfural and 5-hydroxymethylfurfural (5-HMF) coincided with decreasing yields of oligosaccharides. With further increase in severity factor, the concentrations of furans decreased, while the formation of formic acid and lactic acid increased. For example, from severity 3.87 to 4.32, xylose decreased from 6.39 to 5.26 mg/mL, while furfural increased from 1.04 to 1.33 mg/mL; as the severity was further increased to 4.42, furfural diminished to 1.23 mg/mL as formate rose from 0.62 to 1.83 mg/mL. The effects of dilute acid hydrolyzate, acetic acid, and lignin, in particular, on enzymatic hydrolysis were investigated with a rapid microassay method. The microplate method gave considerable time and cost savings compared to the traditional assay protocol, and it is applicable to a broad range of lignocellulosic substrates.

  13. Acid and base hydrolysis of lipid A from Enterobacter agglomerans as monitored by electrospray ionization mass spectrometry: pertinence to detoxification mechanisms.

    Science.gov (United States)

    Wang, Y; Cole, R B

    1996-02-01

    Lipopolysaccharides (LPS), which are endotoxins found in the cell wall of Gram-negative bacteria, are common components of organic dusts that cause or contribute to symptoms associated with organic dust diseases. The lipid A subgroup within LPS is believed to be responsible for the toxicity. Acid and base treatments, which can be effective detoxification methods, were performed on lipid A from Enterobacter agglomerans (EA), a bacterium commonly found in field cotton. Negative-ion electrospray ionization mass spectrometry was employed to characterize the post-treatment structural changes to lipid A. Acid treatment (1% acetic acid, 100 degrees C) hydrolyzed the ester side-chains of lipid A. It was found that the ester-linked palmitoyl group was the most labile to acid hydrolysis. Hydrolysis of the palmitoyl moiety conformed to pseudo-first-order chemical reaction kinetics with a rate constant for decomposition of heptacyl-lipid A from Enterobacter agglomerans of approximately 3.3 x 10(-3) min-1. An order of lability of lipid A acyl side-chains to acid hydrolysis was also deduced: R4' (palmitoyl) > R1' (myristoyl or hydroxymyristoyl) > R3 (hydroxymyristoyl at position 3) > R1 (oxymyristoyl group at position 3') > R2' (lauroyl). Base treatment (0.05 M NaOH in 95% EtOH, 65 degrees C) was shown to be more effective at cleaving ester-linked side-chains. In addition, mass spectral evidence suggests that opening of the pyranose rings of the disaccharide backbone of lipid A and/or removal of the phosphoryl groups may be occurring during base treatment. This study sheds light on mechanistic aspects of treatment procedures leading to the detoxification of endotoxins.

  14. Hydrolysis of palm oil catalyzed by acid%棕榈油的酸催化水解工艺研究

    Institute of Scientific and Technical Information of China (English)

    张玲玲; 王晖

    2015-01-01

    以棕榈油为原料进行常压酸催化水解工艺研究。考察了反应时间、反应温度、催化剂用量、油水质量比及乳化剂用量对棕榈油水解反应的影响,得出棕榈油一次酸催化水解的最佳反应条件:反应时间7 h,反应温度100℃,催化剂浓硫酸用量7.5%,油水质量比1∶1,乳化剂磺酸用量0.5%;在最佳反应条件下棕榈油水解产物酸值(KOH)为192.77 mg/g,水解率达到91.96%。并研究出一套循环水解的工艺流程,实现油脂水解产物的循环利用,提高了水相中甘油的含量。%The hydrolysis of palm oil catalyzed by acid was studied. The effects of reaction time,reaction temperature,catalyst dosage,mass ratio of oil to water and emulsifier dosage on the hydrolysis of palm oil were investigated. The optimal reaction conditions of palm oil hydrolysis were obtained as follows:reaction time 7 h,reaction temperature 100℃,mass ratio of oil to water 1∶1,dosage of sulfonic acid used as emul-sifier 0. 5% and catalyst( concentrated sulfonic acid) dosage 7. 5%. Under the optimal reaction condi-tions,the acid value of the hydrolysates was up to 192. 77 mgKOH/g and the hydrolysis rate of palm oil was 91. 96%. A circulated hydrolysis process was designed, then the recycling of hydrolysates was real-ized,and the content of glycerin in the aqueous phase increased.

  15. Isolation and structural characterization of sugarcane bagasse lignin after dilute phosphoric acid plus steam explosion pretreatment and its effect on cellulose hydrolysis.

    Science.gov (United States)

    Zeng, Jijiao; Tong, Zhaohui; Wang, Letian; Zhu, J Y; Ingram, Lonnie

    2014-02-01

    The structure of lignin after dilute phosphoric acid plus steam explosion pretreatment process of sugarcane bagasse in a pilot scale and the effect of the lignin extracted by ethanol on subsequent cellulose hydrolysis were investigated. The lignin structural changes caused by pretreatment were identified using advanced nondestructive techniques such as gel permeation chromatography (GPC), quantitative (13)C, and 2-D nuclear magnetic resonance (NMR). The structural analysis revealed that ethanol extractable lignin preserved basic lignin structure, but had relatively lower amount of β-O-4 linkages, syringyl/guaiacyl units ratio (S/G), p-coumarate/ferulate ratio, and other ending structures. The results also indicated that approximately 8% of mass weight was extracted by pure ethanol. The bagasse after ethanol extraction had an approximate 22% higher glucose yield after enzyme hydrolysis compared to pretreated bagasse without extraction. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. High conversion of sugarcane bagasse into monosaccharides based on sodium hydroxide pretreatment at low water consumption and wastewater generation.

    Science.gov (United States)

    Wang, Wen; Wang, Qiong; Tan, Xuesong; Qi, Wei; Yu, Qiang; Zhou, Guixiong; Zhuang, Xinshu; Yuan, Zhenhong

    2016-10-01

    The generation of a great quantity of black liquor (BL) and waste wash water (WWW) has been key problems of the alkaline pretreatment. This work tried to build a sustainable way to recycle the BL for pretreating sugarcane bagasse (SCB) and the WWW for washing the residual solid (RS) of alkali-treated SCB which would be subsequently hydrolysed and fermented. The enzymatic hydrolysis efficiency of the washed RS decreased with the recycling times of BL and WWW increasing. Tween80 at the loading of 0.25% (V/V) could notably improve the enzymatic hydrolysis and had no negative impact on the downstream fermentation. Compared with the non-recycling and BL recycling ways based on alkaline pretreatment, the BL-WWW recycling way could not only maintain high conversion of carbohydrate into monosaccharides and save alkali amount of 45.5%, but also save more than 80% water and generate less than 15% waste water.

  17. A study of concentrated acid hydrolysis conversion of lignocellulosic materials to sugars using a co-rotating twin-screw reactor extruder and plug flow reactor

    Science.gov (United States)

    Miller, William Scott

    Concerns about the ability of petroleum to continue supplying ever increasing global energy demands, at a price capable of generating continued economic growth, have spurred innovative research in the field of alternative energy. One alternative energy option that has the ability to provide long-term sustainable energy supplies for the global energy market is the conversion of lignocellulosic materials, via acid hydrolysis, to fermentable sugars for the production of fuel grade ethanol. This research demonstrates the ability of a co-rotating twin-screw reactor extruder and plug flow reactor to continuously convert lignocellulosic materials to fermentable sugars using high temperature concentrated acid hydrolysis. In addition to demonstrating continuous operation of the two-stage concentrated acid hydrolysis system, a number of design of experiments were conducted to model the twin-screw performance and maximize its ability to effectively solubilize lignocellulosic feedstocks in the high shear, elevated temperature, concentrated acid environment. These studies produced a base case twin-screw operating condition used to generate a standard extrudate composition for an extensive high temperature acid hydrolysis batch reactor kinetic modeling study. In this study a number of nonlinear and linear regression analyses were undertaken so that the concentration of less resistant cellulose, or the amount of solublilized extrudate cellulose, resistant cellulose, or non-solubilized extrudate cellulose, glucose, and decomposition products could be obtained as a function of time, temperature, and acid concentration. This study demonstrated that the theoretical cellulose conversion of 51% was limited by the amount of solubilized polysaccharides that could be produced in the twin-screw pretreatment. Further experimentation, showing twin-screw pretreatment lignocellulosic versatility, produced nearly identical results as the southern yellow pine sawdust experiments that were

  18. Enantiomeric Excess Determination for Monosaccharides Using Chiral Transmission to Cold Gas-Phase Tryptophan in Ultraviolet Photodissociation

    Science.gov (United States)

    Fujihara, Akimasa; Maeda, Naoto; Doan, Thuc N.; Hayakawa, Shigeo

    2017-02-01

    Chiral transmission between monosaccharides and amino acids via photodissociation in the gas phase was examined using a tandem mass spectrometer fitted with an electrospray ionization source and a cold ion trap in order to investigate the origin of the homochirality of biomolecules in molecular clouds. Ultraviolet photodissociation mass spectra of cold gas-phase noncovalent complexes of the monosaccharide enantiomers glucose (Glc) and galactose (Gal) with protonated l-tryptophan H+( l-Trp) were obtained by photoexcitation of the indole ring of l-Trp. l-Trp dissociated via Cα-Cβ bond cleavage when noncovalently complexed with d-Glc; however, no dissociation of l-Trp occurred in the homochiral H+( l-Trp)( l-Glc) noncovalent complex, where the energy absorbed by l-Trp was released through the evaporation of l-Glc. This enantioselective photodissociation of Trp was due to the transmission of chirality from Glc to Trp via photodissociation in the gas-phase noncovalent complexes, and was applied to the quantitative chiral analysis of monosaccharides. The enantiomeric excess of monosaccharides in solution could be determined by measuring the relative abundance of the two product ions in a single photodissociation mass spectrum of the cold gas-phase noncovalent complex with H+( l-Trp), and by referring to the linear relationships derived in this work.

  19. Hydrolysis of Cellulose by a Mesoporous Carbon-Fe2(SO4)3/γ-Fe2O3 Nanoparticle-Based Solid Acid Catalyst

    Science.gov (United States)

    Yamaguchi, Daizo; Watanabe, Koki; Fukumi, Shinya

    2016-02-01

    Carbon-based solid acid catalysts have shown significant potential in a wide range of applications, and they have been successfully synthesized using simple processes. Magnetically separable mesoporous carbon composites also have enormous potential, especially in separation and adsorption technology. However, existing techniques have been unable to produce a magnetically separable mesoporous solid acid catalyst because no suitable precursors have been identified. Herein we describe a magnetically separable, mesoporous solid acid catalyst synthesized from a newly developed mesoporous carbon-γ-Fe2O3 nanoparticle composite. This material exhibits an equivalent acid density and catalytic activity in the hydrolysis of microcrystalline cellulose, to that of the cellulose-derived conventional catalyst. Since it is magnetically separable, this material can be readily recovered and reused, potentially reducing the environmental impact of industrial processes to which it is applied.

  20. Optimization of High Solids Dilute Acid Hydrolysis of Spent Coffee Ground at Mild Temperature for Enzymatic Saccharification and Microbial Oil Fermentation.

    Science.gov (United States)

    Wang, Hui-Min David; Cheng, Yu-Shen; Huang, Chi-Hao; Huang, Chia-Wei

    2016-10-01

    Soluble coffee, being one of the world's most popular consuming drinks, produces a considerable amount of spent coffee ground (SCG) along with its production. The SCG could function as a potential lignocellulosic feedstock for production of bioproducts. The objective of this study is to investigate the possible optimal condition of dilute acid hydrolysis (DAH) at high solids and mild temperature condition to release the reducing sugars from SCG. The optimal condition was found to be 5.3 % (w/w) sulfuric acid concentration and 118 min reaction time. Under the optimal condition, the mean yield of reducing sugars from enzymatic saccharification of defatted SCG acid hydrolysate was 563 mg/g. The SCG hydrolysate was then successfully applied to culture Lipomyces starkeyi for microbial oil fermentation without showing any inhibition. The results suggested that dilute acid hydrolysis followed by enzymatic saccharification has the great potential to convert SCG carbohydrates to reducing sugars. This study is useful for the further developing of biorefinery using SCG as feedstock at a large scale.

  1. Importance of acid or alkali concentration on the removal of xylan and lignin for enzymatic cellulose hydrolysis

    NARCIS (Netherlands)

    Murciano-Martinez, P.; Bakker, R.; Harmsen, P.F.H.; Gruppen, H.; Kabel, M.A.

    2015-01-01

    The effect of hemicellulose and lignin solubilisation by H2SO4 and NaOH catalysed pretreatments was correlated to the extent of subsequent enzymatic cellulose hydrolysis. Three different grass-type feedstocks, palm empty fruit bunch, sugarcane bagasse and barley straw, were investigated. Soluble

  2. Importance of acid or alkali concentration on the removal of xylan and lignin for enzymatic cellulose hydrolysis

    NARCIS (Netherlands)

    Murciano-Martinez, P.; Bakker, R.; Harmsen, P.F.H.; Gruppen, H.; Kabel, M.A.

    2015-01-01

    The effect of hemicellulose and lignin solubilisation by H2SO4 and NaOH catalysed pretreatments was correlated to the extent of subsequent enzymatic cellulose hydrolysis. Three different grass-type feedstocks, palm empty fruit bunch, sugarcane bagasse and barley straw, were investigated. Soluble fra

  3. Growth and enzyme production by three Penicillium species on monosaccharides

    DEFF Research Database (Denmark)

    Jørgensen, Henning; Krogh, Astrid Mørkeberg; Krogh, Kristian Bertel Rømer;

    2004-01-01

    The growth and preference for utilisation of various sugar by the Penicillium species Penicillium pinophilum IBT 4186, Penicillium persicinum IBT 13226 and Penicillium brasilianum IBT 20888 was studied in batch cultivations using various monosaccharides as carbon source, either alone or in mixtures...

  4. Kinetics, reactivity, initial-transition state analysis and thermodynamic parameters of base-catalyzed hydrolysis of coumalic acid in solvents with different polarities

    Directory of Open Access Journals (Sweden)

    Ezz A. Abu-Gharib

    2017-02-01

    Full Text Available Base-catalyzed hydrolysis of coumalic acid (COU in binary aqueous-methanol and aqueous-acetone mixtures has been studied kinetically at a temperature range from 283 to 313 K. Moreover, the change in the activation energy barrier of COU from water to water–methanol and water–acetone mixtures is estimated from the kinetic data. Solvent effects on reactivity trends have been analyzed into initial and transition state components by using transfer chemical potentials of the reactants and kinetic data. The transfer chemical potentials δmμθ for COU− anion are derived from solubility data from its calcium, cerium and lanthanum salts. The decrease in rate constant of the base hydrolysis reaction of COU as the percentage of methanol or acetone increases is dominated by transition state (TS. The base hydrolysis reaction of COU follows a rate law with kobs = k2[OH−] and the reaction mechanism was suggested. The high negative values of entropy of activation support the proposal mechanism, i.e. the investigated reaction takes place via the formation of an intermediate complex. Thus, the ring opening of the intermediate complex would be the rate controlling step.

  5. HIDROLISIS ENZIMATIK MINYAK IKAN UNTUK PRODUKSI ASAM LEMAK OMEGA-3 MENGGUNAKAN LIPASE DARI Aspergillus niger [Enzymatic Hydrolysis of Fish Oil for Production of Omega-3 Fatty Acids Using Lipase Derived from Aspergillus niger

    OpenAIRE

    2011-01-01

    Fish oil is the source of important fatty-acid, especially polyunsaturated fatty acid (PUFA) omega-3, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Lipase catalysis activity of Aspergillus niger is low when it is used in fish oil hydrolysis. The activity of the lipase can be increased by adding organic solvent such as hexane into the media. This research aimed to determine temperature, pH and amount of water which produce the highest degree of hydrolysis of fish oil in t...

  6. Effects of organic acids on rice straw on supercritical hydrolysis%超临界下有机酸对稻秆水解糖化的影响

    Institute of Scientific and Technical Information of China (English)

    李星纬; 巩桂芬; 李晓东

    2012-01-01

    With the organic acids ( formic acid, acetic acid, and propionic acid) as the catalyst, hydrolysis saccharification of rice straw in the batch reactor was investigated under the condition of the super- and sub-critical water. The reaction temperature, reaction time and solid-to-liquid ratio for reduction sugar yield were studied. Results showed that organic acid was helpful to the hydrolysis saccharification of straw. Reducing sugar yield could increase when adding organic acid. This trend was most evident when adding formic acid. With the extension of reaction time, reducing sugar yield could gradually decreased. In the appropriate range, reducing sugar production was much higher with the increasing of the solid-liquid ratio. The best conditions on straw hydrolysis saccharification in supercritical water from the experiment were as follows; formic acid concentration 3%, solid-to-liquid ratio 4:60, temperature 410 ℃ , and the reaction time 5 min. Under the conditions, the reducing sugar production reached the highest, 6. 65 g/L.%采用间歇式反应器在超临界条件下,以有机酸(甲酸、乙酸和丙酸)为催化剂对稻秆进行水解糖化研究,重点考察反应温度、反应时间、固液比对还原糖产率的影响.实验表明:有机酸的加入有利于稻秆的水解糖化,稻秆水解速率和还原糖产量都有所提高,这种趋势在加入甲酸时最为明显;随着反应时间的延长,还原糖产量会逐渐减少;适当提高固液比有助于增加还原糖产量.稻秆超临界水解糖化的最佳条件:甲酸体积分数3%、固液比4∶60(g/mL)、反应温度410℃、反应时间5 min,在此条件下,还原糖产量最高,达6.65 g/L.

  7. Rapid Determination of the Monosaccharide Composition and Contents in Tea Polysaccharides from Yingshuang Green Tea by Pre-Column Derivatization HPLC

    Directory of Open Access Journals (Sweden)

    Yujie Ai

    2016-01-01

    Full Text Available A pre-column derivatization high-performance liquid chromatography (HPLC method was developed and optimized to characterize and quantify the monosaccharides present in tea polysaccharides (TPS isolated from Yingshuang green tea. TPS sample was hydrolyzed with trifluoroacetic acid, subjected to pre-column derivatization using 1-phenyl-3-methyl-5-pyrazolone (PMP, and separated on an Agilent TC-C18 column (4.6 mm × 250 mm, 5 μm with UV detection at 250 nm. A mixture of ten PMP derivatives of standard monosaccharides (mannose, ribose, rhamnose, glucuronic acid, galacturonic acid, glucose, xylose, galactose, arabinose, and fucose could be baseline separated within 20 min. Moreover, quantitative analysis of the component monosaccharides in Yingshuang green tea TPS was achieved, indicating the TPS consisted of mannose, ribose, rhamnose, glucuronic acid, galacturonic acid, glucose, xylose, galactose, and arabinose in the molar contents of 0.72, 0.78, 0.89, 0.13, 0.15, 0.36, 0.39, 0.36, 0.36, and 0.38 μM, respectively. Recovery efficiency for component monosaccharides from TPS ranged from 93.6 to 102.4% with RSD values lower than 2.5%. In conclusion, pre-column derivatization HPLC provides a rapid, reproducible, accurate, and quantitative method for analysis of the monosaccharide composition and contents in TPS, which may help to further explore the relationship between TPS monosaccharides isolated from different tea varieties and their biological activity.

  8. Enzymatic hydrolysis of corn bran arabinoxylan

    DEFF Research Database (Denmark)

    Agger, Jane

    This thesis concerns enzymatic hydrolysis of corn bran arabinoxylan. The work has focused on understanding the composition and structure of corn bran with specific interest in arabinoxylan with the main purpose of targeting enzymatic hydrolysis for increased yields. Corn bran has been used...... as a model substrate because it represents a readily available agroindustrial side product with upgrading potentials. Corn bran originates from the wet-milling process in corn starch processing, is the outmost layers of the corn kernel and is particularly rich in pentose monosaccharides comprising the major...... components of arabinoxylan. Corn bran is one of the most recalcitrant cereal byproducts with arabinoxylans of particular heterogeneous nature. It is also rich in feruloyl derived substitutions, which are responsible for extensive cross-linking between arabinoxylan molecules and thereby participate...

  9. Improvement of hemicellulose hydrolysis of corncobs

    Energy Technology Data Exchange (ETDEWEB)

    Nikolaeva, N.S.; Filatova, A.M.; Barysheva, O.N.; Abroskina, L.A.; Andrianova, A.K.

    1981-01-01

    Impregnation of corncobs with H/sub 2/SO/sub 4/ solution at 80-90 degrees, hydrolysis with 1.5% H/sub 2/SO/sub 4/ at 120-125 degrees, and 2-stage extraction of hydrolysis products from lignocellulose with sugar solution, obtained in the 1st stage of extraction, at 60-80 degrees gave hydrolysates containing 8.2% reducing substances with pentose yield of 36.0%. By this method, the content of actual sugar, monosaccharides (after clarification with ion exchangers) and xylose in hydrolysates was increased from 80.2% to 88.0%, 93% to 96% and 76.3% to 78.8%, respectively, whereas the content of arabinose, glucose, and galactose was decreased from 23.7% to 21.2%.

  10. Isolation of pectin from pumpkin (Cucurbita moschata, L.) by acid hydrolysis;Isolamento de pectina de abobora (Cucurbita moschata, L.) por hidrolise acida

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Jose R.R.; Ricardo, Nagila M.P.S.; Paula, Regina C.M. de; Feitosa, Judith P.A., E-mail: judith@dqoi.ufc.b [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil). Dept. de Quimica Organica e Inorganica. Lab. de Polimeros; Brito, Edy S. [EMBRAPA Agroindustria Tropical, Fortaleza, CE (Brazil)

    2009-07-01

    Pumpkin (Cucurbita moschata, L.) constitutes an excellent source of carotenoids, precursors of vitamin A. Besides, it also that constitutes also a great natural source of low-cost pectin. Pectin is a heterogeneous complex polysaccharide found in the primary cell wall of most plants and its effect on health is receiving increasing interest from the scientific community. In this work, high-methoxy pectin was obtained from pumpkin (Cucurbita moschata, L.) through the acid hydrolysis methodology. The pectin obtained was characterized by FTIR, NMR {sup 1}H, GPC and rheology. (author)

  11. Super acid catalysed sequential hydrolysis/cycloisomerization of -(acetylenic)benzamides under microwave condition: Synthesis, antinociceptive and antiinflammatory activity of substituted isocoumarins

    Indian Academy of Sciences (India)

    Chandrasekaran Praveen; P Dheenkumar; P T Perumal

    2013-01-01

    Synthesis of isocoumarins and related compounds via triflic acid promoted hydrolysis/cyclization sequence of 2-(alkynyl)benzamides under microwave condition was achieved. The substrate scope of the reaction was broad to include not only aromatic but also polyaromatic and heteroaromatic motifs, thus highlighting the significance of this methodology. One-pot operation, short reaction time, good chemical yields and excellent regioselectivity are the advantages of this protocol. All the synthesized compounds were evaluated for their antinociceptive and antiinflammatory activities using in vivo rodent models.

  12. Amino Acid Hydrolysis and Analysis System for Investigation of Site Directed Nucleation and Growth of Ceramic Films on Metallic Surfaces

    Science.gov (United States)

    2008-09-30

    of biomineralization by hemocytes isolated from a bivalve on a metal substrate outside of the organism. These results indicate that it is possible...to deposit a ceramic material onto a metal substrate at ambient temperature and pressure. Figure I A-B. SEM evidence of cellular biomineralization on...hydrolysis and analysis system for investigation of site directed nucleation and growth of cera1nic films on metallic surfaces Sb. GRANT NUMBER

  13. 稻草秸秆超低酸水解及水解产物分析%Hydrolysis of Rice Straw with Extremely Dilute Acid and Products Analysis

    Institute of Scientific and Technical Information of China (English)

    王为国; 李自豪; 覃远航; 吕仁亮; 张俊峰; 王存文

    2013-01-01

    The hydrolysis of rice straw with extremely dilute sulfuric acid(0.05%(w)) was conducted.It was found that the optimal solid content and stirring speed for the rice straw hydrolysis were 0.050 0 g/mL and 700 r/min,respectively.The change of the hydrolysis with time was investigated in the temperature range of 160-210 ℃.The results indicated that,in the hydrolysis,there was a single-peak of reducing sugar content at 160 ℃,in the temperature range of 170-200 ℃there was a double-peak,and a single-peak reappeared at 210 ℃.The reason was that the reducing sugar concentration from the hydrolysis of hemicellulose and cellulose showed two peaks,and the peaks superimposed or separated as the hydrolysis temperature changed.The hydrolysis products and solid residues were characterized by means of FTIR and HPLC.The results showed that,most of hemicellulose hydrolyzed and disappeared,the structure of the lignin was destroyed to a certain extent,the polymerization degree of the cellulose decreased greatly but its crystallinity was still high.The main hydrolysis products were cellotriose,cellobiose,glucose,xylose,methylglyoxal and some unknown compounds.%用0.05%(w)的稀硫酸对湖北省稻草秸秆进行水解,考察了混合原料中固体含量和搅拌转速对稻草秸秆水解的影响.实验结果表明,最佳秸秆颗粒的质量浓度为0.050 0 g/mL,最佳转速为700 r/min.研究了稻草秸秆在160~ 210℃内的水解趋势.研究结果表明,160℃时,稻草秸秆水解得到的还原糖含量随水解的进行呈单峰趋势;在170~ 200℃时呈双峰趋势;当温度达到210℃时又呈现单峰趋势,这与稻草秸秆中纤维素和半纤维素水解得到的两个还原糖峰随水解的进行呈现叠加和分离有关.表征固体残渣并分析水解产物组成的结果显示,水解后半纤维素大部分水解,木质素的结构在一定程度上被破坏,纤维素的聚合度急剧降低但结晶度仍较高;水解产物主要为

  14. Joint action of ultrasonic and Fe³⁺ to improve selectivity of acid hydrolysis for microcrystalline cellulose.

    Science.gov (United States)

    Li, Jinbao; Qiang, Dandan; Zhang, Meiyun; Xiu, Huijuan; Zhang, Xiangrong

    2015-09-20

    In this study, the combination of Fe(3+)/HCl and ultrasonic treatment was applied to selectively hydrolyze cellulose for the preparation of microcrystalline cellulose (MCC). It was found that the crystallinity and specific surface area of hydrocellulose samples were higher (78.92% and 2.23581 m(2)g(-1), respectively), compared with the method that only used Fe(3+)/HCl catalyst without ultrasonic treatment. Meanwhile, the hydrolysate can be extracted and reused for cellulose hydrolysis for three runs, which was effective in saving the dosage of chemicals and reducing the pollution of the environment without affecting the properties of hydrocellulose. Moreover, the increased concentration of total reducing sugar (TRS) after three runs may be used as a valuable source in biofuels production. The technology of cellulose hydrolysis, by retaining the crystalline region for MCC products while promoting hydrolysis of amorphous region for further utilization is of great novelty, which may prove valuable in converting biomass into chemicals and biofuels, environmentally and economically. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Pretreatment by NaOH swelling and then HCl regeneration to enhance the acid hydrolysis of cellulose to glucose.

    Science.gov (United States)

    Sun, Binzhe; Peng, Gege; Duan, Lian; Xu, Aihua; Li, Xiaoxia

    2015-11-01

    A simple pretreatment method, NaOH swelling at a low temperature and then HCl regeneration, was developed for depolymerization of cellulose to glucose. Cellulose was transformed into amorphous hydrogel during the treatment; and due to the easy diffusion of H(+) and Cl(-) ions into the cellulose hydrogel network as well as the strong ability of Cl(-) to disrupt the massive hydrogen bond, the hydrolysis rate was greatly enhanced. The method is effective for α-cellulose, microcrystalline cellulose, filter paper, ramie fiber and absorbent cotton. Even at a high α-cellulose concentration of 50g/L, 29.1% yield of glucose was still obtained within 10min at 160°C under microwave irradiation, where up to 16.2g/L of glucose solution was given. The influence of NaOH concentration, HCl concentration, hydrolysis temperature and time on the hydrolysis rate was investigated. The structure of cellulose hydrogel was also studied to confirm the reaction mechanism. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Using of acid hydrolysis for preparation of porous starch and feature analysis%酸法制备多孔淀粉及其特性研究

    Institute of Scientific and Technical Information of China (English)

    李梅; 刘可志; 徐雅雯; 孙平

    2012-01-01

    Porous starch was made of corn starch by using of different concentrations of hydrochloric acid or compound enzyme under certain conditions.The morphology and some properties of the prepared porous starch were determined.Water absorption and oil absorption of the two products were compared.The results showed that the porous starch which made in the conditions of solid to liquid ratio 1:4,the concentration of hydrochloric acid 8% ,temperature 45~(3 and time 20h was similar to that made by enzymatic hydrolysis on water absorption and oil absorption,and the property was greatly improved on the basis of the native starch.The SEM results showed that the surface of porous starch made by enzymatic hydrolysis was covered with holes and pits. But the starch granules made by acid hydrolysis were random, and the effect was worse than enzymatic hydrolysis. Compared with native starch,gelatinization start temperature of porous starch was slightly increased but peak viscosity was decreased in a great degree.With high price advantage than enzymatic hydrolysis,acid hydrolysis was simple and inexpensive,and had industrial production value.%以玉米淀粉为原料,分别用不同浓度的盐酸溶液和复合酶在一定条件下制备多孔淀粉。对制得的多孔淀粉进行形态结构和部分性质的测定,并对两种方式处理所得产品的吸水性和吸油性进行对比。结果显示,料液比1:4、8%浓度的盐酸溶液、45℃下水浴反应20h制备的多孔淀粉在吸水和吸油性能上与酶法制备的多孔淀粉较为相似,同时相对于原淀粉性能有很大的提高。扫描电子显微镜(SEM)显示,酶法制备的多孔淀粉表面布有类似蜂窝状的孔洞或凹坑,而酸法制得的多孔淀粉颗粒具有随机性,效果不如酶法处理。与原淀粉相比,酸法制备的多孔淀粉糊化开始温度略微升高,而峰值黏度有很大降低。酸法制备多孔淀粉的方法简单廉价,相对酶

  17. Recovery of acetic acid from pre-hydrolysis liquor of hardwood kraft-based dissolving pulp production process by reactive extraction with triisooctylamine.

    Science.gov (United States)

    Yang, G; Jahan, M Sarwar; Ahsan, Laboni; Zheng, Linqiang; Ni, Yonghao

    2013-06-01

    Acetic acid was one of the main compositions of the pre-hydrolysis liquor (PHL), which was recovered by reactive extraction with triisooctylamine (TIOA) diluted with decanol. Dilution of TIOA played an important role in extracting acetic acid from the PHL. The recovery of acetic acid from the PHL by TIOA was increased from 10.34% to 66.60% with the dilution of TIOA to 20% by decanol at the HAc to TIOA molar ratio of 1, consequently, the equilibrium distribution coefficient KD increased. The effects of time, temperature and pH on the extraction process were also studied. The extraction process was very fast. The acetic acid extraction decreased from 65.13% to 57.34% with the rise of temperature to 50°C from 20°C. A higher pH increased the dissociation of acetic acid, as a result, decreased acetic acid extraction. The hemicelluloses in the PHL were unaffected on the extraction process of acetic acid.

  18. Cellulose whiskers from sisal fibers: a study about the variable of extraction by acid hydrolysis; Whiskers de cellulose obtido a partir de fibras de sisal: estudo de variaveis de extracao por hidrolise acida

    Energy Technology Data Exchange (ETDEWEB)

    Teodoro, Kelcilene B.R., E-mail: rakelcilene@ig.com.br [Universidade Federal de Sao Carlos - UFSCar, Sao Carlos, SP (Brazil); Teixeira, Eliangela de Morais; Correa, Ana Carolina; Campos, Adriana de; Marconcini, Jose Manoel; Mattoso, Luiz Henrique Capparelli [Empresa Brasileira de Pesquisa Agropecuaria - EMBRAPA, Sao Carlos, SP (Brazil). Lab. Nacional de Nanotecnologia para o Agronegocio (LNNA)

    2011-07-01

    The incorporation of cellulosic nanostructures in polymeric matrices has been studied due to their properties of biodegradation, and expected higher mechanical performance than the traditional composites. In this work, cellulose nanofibers were obtained from sisal bleached with reagents without chlorine, where it was used an acid mixture, with acetic acid and nitric acid, and after the bleached fibers were submitted to acid hydrolysis. The influence of the temperature and time of hydrolysis on the morphology and dimensions, crystallinity and thermal stability were analyzed by scanning transmission electronic microscopy (TEM), x-ray diffraction (XRD) and thermogravimetric analysis (TGA), respectively. The hydrolysis condition of 60 deg C and 15 minutes showed to be the most effective condition to obtain whiskers from sisal fibers, resulting in nanostructures with higher crystallinity and thermal. (author)

  19. Evaluation of jumbo squid (Dosidicus gigas byproduct hydrolysates obtained by acid-enzymatic hydrolysis and by autohydrolysis in practical diets for Pacific white shrimp (Litopenaeus vannamei

    Directory of Open Access Journals (Sweden)

    Mayra Lizett González-Félix

    2014-09-01

    Full Text Available The marine bioprocessing industry offers great potential to utilize byproducts for fish meal replacement in aquafeeds. Jumbo squid is an important fishery commodity in Mexico, but only the mantle is marketed. Head, fins, guts and tentacles are discarded in spite of being protein-rich byproducts. This study evaluated the use of two jumbo squid byproduct hydrolysates obtained by acid-enzymatic hydrolysis (AEH and by autohydrolysis (AH as ingredients in practical diets for shrimp. The hydrolysates were included at levels of 2.5 and 5.0% of the diet dry weight in four practical diets, including a control diet without hydrolysate. Shrimp growth and survival were not significantly affected by the dietary treatments. Postharvest quality of abdominal muscle was evaluated in terms of proximate composition and sensory evaluation. Significantly higher crude protein was observed in the muscle of shrimp fed the highest hydrolysate levels, AH 5% (204.8 g kg- 1 or AEH 5% (201.3 g kg- 1. Sensory analysis of cooked muscle showed significant differences for all variables evaluated: color, odor, flavor, and firmness. It was concluded that Jumbo squid byproducts can be successfully processed by autohydrolysis or acid-enzymatic hydrolysis, and that up to 5.0% of the hydrolysates can be incorporated into shrimp diets without affecting growth or survival.

  20. Enteric-coated capsule containing β-galactosidase-loaded polylactic acid nanocapsules: enzyme stability and milk lactose hydrolysis under simulated gastrointestinal conditions.

    Science.gov (United States)

    He, Hongjun; Zhang, Xueting; Sheng, Yan

    2014-11-01

    In order to protect peroral β-galactosidase from being degraded and hydrolyse milk lactose efficiently in the environments of gastrointestinal tract, a double-capsule delivery system composed of enteric-coated capsule and polylactic acid (PLA) nanocapsules (NCs) was developed for encapsulation of β-galactosidase. β-galactosidase-loaded PLA NCs in the size range of 100-200 nm were prepared by a modified w1/o/w2 technique. During the encapsulation process, dichloromethane/ethyl acetate (1 : 1, v/v) as the solvent composition, high-pressure homogenisation (150 bar, 3 min) as the second emulsification method and polyvinyl alcohol or Poloxamer 188 as a stabiliser in the inner phase could efficiently improve the activity retention of β-galactosidase (>90%). Subsequently, the prepared NCs were freeze-dried and filled in a hydroxypropyl methylcellulose phthalate (HP55)-coated capsule. In vitro results revealed that the HP55-coated capsule remained intact in the simulated gastric fluid and efficiently protected the nested β-galactosidase from acidic denaturation. Under the simulated intestinal condition, the enteric coating dissolved rapidly and released the β-galactosidase-loaded PLA NCs, which exhibited greater stability against enzymatic degradation and higher hydrolysis ratio (∼100%) towards milk lactose than the free β-galactosidase. These results suggest that this double-capsule delivery system represents promising candidate for efficient lactose hydrolysis in the gastrointestinal tract.

  1. The use of sub-critical water hydrolysis for the recovery of peptides and free amino acids from food processing wastes. Review of sources and main parameters.

    Science.gov (United States)

    Marcet, Ismael; Álvarez, Carlos; Paredes, Benjamín; Díaz, Mario

    2016-03-01

    Food industry processing wastes are produced in enormous amounts every year, such wastes are usually disposed with the corresponding economical cost it implies, in the best scenario they can be used for pet food or composting. However new promising technologies and tools have been developed in the last years aimed at recovering valuable compounds from this type of materials. In particular, sub-critical water hydrolysis (SWH) has been revealed as an interesting way for recovering high added-value molecules, and its applications have been broadly referred in the bibliography. Special interest has been focused on recovering protein hydrolysates in form of peptides or amino acids, from both animal and vegetable wastes, by means of SWH. These recovered biomolecules have a capital importance in fields such as biotechnology research, nutraceuticals, and above all in food industry, where such products can be applied with very different objectives. Present work reviews the current state of art of using sub-critical water hydrolysis for protein recovering from food industry wastes. Key parameters as reaction time, temperature, amino acid degradation and kinetic constants have been discussed. Besides, the characteristics of the raw material and the type of products that can be obtained depending on the substrate have been reviewed. Finally, the application of these hydrolysates based on their functional properties and antioxidant activity is described.

  2. HIDROLISIS ENZIMATIK MINYAK IKAN UNTUK PRODUKSI ASAM LEMAK OMEGA-3 MENGGUNAKAN LIPASE DARI Aspergillus niger [Enzymatic Hydrolysis of Fish Oil for Production of Omega-3 Fatty Acids Using Lipase Derived from Aspergillus niger

    Directory of Open Access Journals (Sweden)

    Sapta Raharja*

    2011-06-01

    Full Text Available Fish oil is the source of important fatty-acid, especially polyunsaturated fatty acid (PUFA omega-3, such as eicosapentaenoic acid (EPA and docosahexaenoic acid (DHA. Lipase catalysis activity of Aspergillus niger is low when it is used in fish oil hydrolysis. The activity of the lipase can be increased by adding organic solvent such as hexane into the media. This research aimed to determine temperature, pH and amount of water which produce the highest degree of hydrolysis of fish oil in the presence of hexane. Correlation between the highest degree of hydrolysis and the amount of omega-3 fatty acid was also investigated. The variables used in this research were temperatures (25-65 oC, pH (5-9, and water addition (1-5 %v/v. The highest degree of enzymatic hydrolysis of fish oil in the media without hexane was 28.07 % that was reached at 45oC and pH 5. In the presence of hexane, the highest degree of hydrolysis was 75.12 % which was reached at 5% water addition, temperature 45oC, and pH 5. GC-MS analysis showed that omega-3 fatty acid content especially EPA and DHA increased along with increase in the degree of hydrolysis. Concentration of omega-3 fatty acid produced without hexane addition was 18.42 % with EPA amounted to 12,17% and DHA 0,86%. Meanwhile omega-3 fatty acid content in the presence of hexane reached 21.93 % with EPA amounted to 17.75 % and DHA 1.21 %.

  3. Monosaccharides in the water of the Gulf of Gdansk

    Directory of Open Access Journals (Sweden)

    Waldemar Grzybowski

    2001-06-01

    Full Text Available The concentration of monosaccharides in samples collected in the Gulf of Gdansk area was determined in water filtered through ~0.8 µm pore size filters. Seawater concentrations ranged from about 0.2 to 1.1 mg C dm-3, the highest values being detected at the mouth of the river Vistula. Seasonality was detectable in the data distribution; the majority of autumn values lay within the 0.2–0.4 range while concentrations in the spring samples were higher and the values more widely scattered. Measurements of monosaccharide concentrations at selected points during the whole observation period showed that values increased from spring to autumn as much as 5-fold. Concomitant analyses in Vistula river water yielded concentrations from 0.4 to 1.2 mg C dm-3. These latter values were all higher than those recorded in seawater in the corresponding months.

  4. One-pot enzymatic synthesis of docosahexaenoic acid-rich triacylglycerols at the sn-1(3) position using by-product from selective hydrolysis of tuna oil.

    Science.gov (United States)

    Nagao, Toshihiro; Watanabe, Yomi; Maruyama, Kazuaki; Momokawa, Yuusuke; Kishimoto, Noriaki; Shimada, Yuji

    2011-01-31

    Docosahexaenoic acid (DHA)-rich oil has been industrially produced by selective hydrolysis of tuna oil with a lipase that acts weakly on DHA. The free fatty acids (FFAs) generated in this process as by-products contain a high DHA concentration (46wt%) but are treated as industrial waste. This study attempted to reuse these by-product FFAs using a one-pot process, and succeeded in producing triacylglycerols (TAGs) through the esterification of the by-product FFAs with glycerol using immobilized Rhizomucor miehei lipase. Regiospecific analysis of the resulting TAGs showed that the content of DHA at the sn-1(3) position (51.7mol%) was higher than the content of DHA at the sn-2 position (17.3mol%). The DHA distribution in TAGs synthesized in this study was similar to the DHA distribution in TAGs from seal oil.

  5. Direct conversion of cellulose to glycolic acid with a phosphomolybdic acid catalyst in a water medium

    KAUST Repository

    Zhang, Jizhe

    2012-08-03

    Direct conversion of cellulose to fine chemicals has rarely been achieved. We describe here an eco-benign route for directly converting various cellulose-based biomasses to glycolic acid in a water medium and oxygen atmosphere in which heteromolybdic acids act as multifunctional catalysts to catalyze the hydrolysis of cellulose, the fragmentation of monosaccharides, and the selective oxidation of fragmentation products. With commercial α-cellulose powder as the substrate, the yield of glycolic acid reaches 49.3%. This catalytic system is also effective with raw cellulosic biomass, such as bagasse or hay, as the starting materials, giving rise to remarkable glycolic acid yields of ∼30%. Our heteropoly acid-based catalyst can be recovered in solid form after reaction by distilling out the products and solvent for reuse, and it exhibits consistently high performance in multiple reaction runs. © 2012 American Chemical Society.

  6. 超声与酸协同水解马铃薯淀粉研究%Study on potato starch hydrolysis under combination of ultrasound and acid

    Institute of Scientific and Technical Information of China (English)

    胡爱军; 李立; 郑捷; 孟欣; 安莉莉; 卢静

    2014-01-01

    以马铃薯淀粉为原料,在超声作用下酸水解制备马铃薯改性淀粉。研究了盐酸添加量、超声温度、超声时间、超声功率对马铃薯淀粉酸解的影响,在单因素实验的基础上进行了正交实验。结果表明,超声作用下酸解马铃薯淀粉的适宜工艺参数为盐酸添加量7%,超声温度55℃,超声时间75 min,超声功率600 W。且超声协同酸改性的马铃薯淀粉峰值黏度下降92.07%。对比无超声作用的酸解淀粉,有超声作用的酸解淀粉黏度降低14.63%。因此,超声作用明显促进了马铃薯淀粉的酸解改性。%With potato starch as raw materia, modified potato starch was prepared by acid hydrolysis under ultrasound. The effects of hydrochloric acid dosage, temperature, time, and ultrasound power were investigated. Based on above investigations, an orthogonal experiment was carried out. The result showed that the optimal technological conditions of acid-hydrolyzed potato starch preparation with ultrasound were as follows: hydrochloric acid at 7%, ultrasonic temperature at 55 ℃ , ultrasonic time at 75 min, ultrasonic power at 600 W. And the peak value of viscosity of potato starch under the combination of acid and ultrasound showed a decrease of 92.07%. With ultrasound, the viscosity of acid-modified starch decreased 14.63% than that without ultrasound. Obviously, ultrasound promoted the acid hydrolysis of potato starch.

  7. Potential of amylolytic lactic acid bacteria to replace the use of malt for partial starch hydrolysis to produce African fermented pearl millet gruel fortified with groundnut.

    Science.gov (United States)

    Songré-Ouattara, L T; Mouquet-Rivier, C; Icard-Vernière, C; Rochette, I; Diawara, B; Guyot, J P

    2009-04-15

    Fermentation and starch hydrolysis of a pre-cooked pearl millet-groundnut (MG) slurry inoculated with amylolytic lactic acid bacteria (ALAB) or by back slopping was investigated as a substitute for the addition of malt to prepare infant gruels. The ALAB collection strain Lb. plantarum A6, and the endogenous microflora provided by back slopping were more efficient in acidifying and partially hydrolysing starch in the MG slurry than Lb. plantarum 6.1, isolated from the traditional process in Burkina Faso. Large amounts of maltotriose and maltotetraose accumulated in slurry fermented by strain A6. No accumulation of maltose was observed, which could be an advantage to prevent the growth of microbial contaminants such as yeasts. Starch hydrolysis in the MG slurry inoculated with strain A6 or by back slopping enabled preparation of high-energy density gruels (84.7+/-4.4 and 80.4+/-23.8 kcal/100 g of gruel, respectively) of liquid consistency. However variability was higher with back slopping.

  8. The effect of microcrystalline cellulose crystallinity on the hydrophilic property of tablets and the hydrolysis of acetylsalicylic acid as active pharmaceutical ingredient inside tablets.

    Science.gov (United States)

    Awa, Kimie; Shinzawa, Hideyuki; Ozaki, Yukihiro

    2015-08-01

    The crystal structures of active pharmaceutical ingredients and excipients should be strictly controlled because they influence pharmaceutical properties of products which cause the change in the quality or the bioavailability of the products. In this study, we investigated the effects of microcrystalline cellulose (MCC) crystallinity on the hydrophilic properties of tablets and the hydrolysis of active pharmaceutical ingredient, acetylsalicylic acid (ASA), inside tablets by using tablets containing 20% MCC as an excipient. Different levels of grinding were applied to MCC prior to tablet formulation, to intentionally cause structural variation in the MCC. The water penetration and moisture absorbability of the tablets increased with decreasing the crystallinity of MCC through higher level of grinding. More importantly, the hydrolysis of ASA inside tablets was also accelerated. These results indicate that the crystallinity of MCC has crucial effects on the pharmaceutical properties of tablets even when the tablets contain a relatively small amount of MCC. Therefore, controlling the crystal structure of excipients is important for controlling product qualities.

  9. Fermentative l-lactic acid production from pretreated whole slurry of oil palm trunk treated by hydrothermolysis and subsequent enzymatic hydrolysis.

    Science.gov (United States)

    Eom, In-Yong; Oh, Young-Hoon; Park, Si Jae; Lee, Seung-Hwan; Yu, Ju-Hyun

    2015-06-01

    A simple and cost-effective biochemical conversion process consisting of hydrothermal treatment, enzymatic hydrolysis and fermentation of pretreated whole slurry (PWS) was developed for producing l-lactic acid (L-LA) from oil palm trunk (OPT). When OPT was hydrothermally treated at optimal condition capable of achieving maximum yield of hemicellulosic sugars after enzymatic hydrolysis, the enzymatic digestibility of the PWS afforded a yield of 81.4% of the theoretical glucose yield (TGY). However, glucose yield from washed pretreated solid (WPS) was only 43.5% of TGY. The use of two hydrolysates from PWS and WPS for fermentation by Lactobacillus paracasei engineered to selectively produce L-LA afforded yields of 89.5% and 45.8% of the theoretical LA yield (TLY), respectively. This study confirmed the inevitable extensive sugar loss during washing of pretreated slurry due to loss of soluble starch. Alternatively, the proposed design process is considered suitable for converting OPT to L-LA without such starch loss. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Co-hydrolysis of hydrothermal and dilute acid pretreated populus slurries to support development of a high-throughput pretreatment system

    National Research Council Canada - National Science Library

    Studer, Michael H; Brethauer, Simone; Demartini, Jaclyn D; McKenzie, Heather L; Wyman, Charles E

    2011-01-01

    ..., a streamlined approach we term 'co-hydrolysis' was developed. In this method, the solids and liquid in the pretreated biomass slurry are not separated, but instead hydrolysis is performed by adding enzymes to the whole pretreated slurry...

  11. Hydrolysis and rearrangement of phthalamic acid derivatives and assessment of their potential as prodrug forms for amines

    DEFF Research Database (Denmark)

    Bundgaard, H; Steffansen, B

    1990-01-01

    ] has claimed that N-(3-bromopropyl)phthalamic acid is very easily hydrolyzed in mildly alkaline solutions by an intramolecular catalytic effect of the ionized carboxy group. In this study, the degradation behaviour of N-(2-bromoethyl)phthalamic acid (I), N-(3-bromopropyl)phthalamic acid (II....... It is concluded that phthalamic acid derivatives are too stable chemically and enzymatically to be considered as prodrug forms for primary or secondary amines....

  12. Effect of Acid Hydrolysis Temperature and Time on Properties of Corn Starch%酸解温度和时间对玉米淀粉性能的影响

    Institute of Scientific and Technical Information of China (English)

    左迎峰; 顾继友; 张彦华; 谭海彦

    2012-01-01

    Acid hydrolytic com starch was prepared with hydrochloric acid hydrolysis method by taking corn starch as raw material. The influences of acid hydrolysis temperature and time duration on structure and properties of the acid hydrolytic corn starch were studied. The crystallinity, gelatinization viscosity, gelatinization temperature and the thermal performance of the acid hydrolysis starch were analyzed by X ray diffraction (XRD) , rotational viscometer, differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA) respectively. The results showed that the crystallinity and gelatinization temperature were increased first and then decreased along with the increase of acid hydrolysis temperature and time duration. Gelatinization viscosity was rapidly decreased with the increase of acid hydrolysis temperature and time duration. The thermal stability of com starch was slightly influenced by acid modification.%以玉米淀粉为原料,研究盐酸制备酸解玉米淀粉,考察酸解温度和酸解时间对酸解玉米淀粉结构和性能的影响.通过X射线衍射(XRD)、旋转黏度计、差示扫描量热法(DSC)和热重分析(TGA)对酸解淀粉的结晶度、糊化黏度、糊化温度和热性能进行分析,结果表明:结晶度和糊化温度随酸解温度的升高和酸解时间的延长表现为先增大后减小;糊化黏度随酸解温度的升高和酸解时间的延长而迅速降低;酸解改性对玉米淀粉的热稳定性影响较小.

  13. Hydrolysis-acidogenesis of food waste in solid-liquid-separating continuous stirred tank reactor (SLS-CSTR) for volatile organic acid production.

    Science.gov (United States)

    Karthikeyan, Obulisamy Parthiba; Selvam, Ammaiyappan; Wong, Jonathan W C

    2016-01-01

    The use of conventional continuous stirred tank reactor (CSTR) can affect the methane (CH4) recovery in a two-stage anaerobic digestion of food waste (FW) due to carbon short circuiting in the hydrolysis-acidogenesis (Hy-Aci) stage. In this research, we have designed and tested a solid-liquid-separating CSTR (SLS-CSTR) for effective Hy-Aci of FW. The working conditions were pH 6 and 9 (SLS-CSTR-1 and -2, respectively); temperature-37°C; agitation-300rpm; and organic loading rate (OLR)-2gVSL(-1)day(-1). The volatile fatty acids (VFA), enzyme activities and bacterial population (by qPCR) were determined as test parameters. Results showed that the Hy-Aci of FW at pH 9 produced ∼35% excess VFA as compared to that at pH 6, with acetic and butyric acids as major precursors, which correlated with the high enzyme activities and low lactic acid bacteria. The design provided efficient solid-liquid separation there by improved the organic acid yields from FW.

  14. Comparison of starch hydrolysis activity and thermal stability of two Bacillus licheniformis alpha-amylases and insights into engineering alpha-amylase variants active under acidic conditions.

    Science.gov (United States)

    Lee, Seunjae; Oneda, Hiroshi; Minoda, Masashi; Tanaka, Akiyoshi; Inouye, Kuniyo

    2006-06-01

    Bacillus licheniformis alpha-amylase (BLA) is widely used in various procedures of starch degradation in the food industry, and a BLA species with improved activity at higher temperature and under acidic conditions is desirable. Two BLA species, designated as PA and MA, have been isolated from the wild-type B. licheniformis strain and a mutant strain, respectively. In this study, their starch-hydrolysis activity and thermal stability were examined. MA showed higher activity than PA, especially at acidic pH (pH 5.0-5.5), and even after 1 h of treatment at 90 degrees C. MA was active in the range of pH 4.0-8.0, which is much wider than that (pH 4.5-7.5) of PA. It was shown that the proton dissociation constants on the acidic and alkaline sides (pKa1 and pKa2) were shifted to more acidic and basic values, respectively, by the mutation of PA to MA. The activation energy and thermodynamic parameters for their thermal inactivation indicate that MA is more thermally stable and catalytically active than PA, suggesting that MA could be useful for glucose-production process coupled with reactions catalyzed by beta-amylase.

  15. 醋酸水解玉米芯中木聚糖的动力学%Kinetics of acetic acid hydrolysis for xylan from corn cobs

    Institute of Scientific and Technical Information of China (English)

    岳昌海; 薄德臣; 李凭力

    2011-01-01

    利用醋酸作为催化剂水解玉米芯中半纤维素来制备还原糖,测定了温度在160-200℃、固液质量比为1∶15、搅拌速度为500 r/min下,不同水解时间水解液中还原糖的收率以及副产物糠醛的收率.利用半纤维素高温液态水的Garrote模型拟合还原糖生成过程.实验表明,该模型能够较好地描述还原糖生成过程以及副产物糠醛的产生过程.通过曲线拟合确定了不同水解温度下还原糖的生成速率以及降解速率,同时利用Arrhenius方程确定木聚糖降解活化能为98.538 kJ/mol以及还原糖降解活化能为172 kJ/mol.综合比较不同温度下水解液中的还原糖以及糠醛质量浓度,确定使用质量分数为5%的醋酸于180℃下水解19 min为最佳水解条件.在此条件下水解液中还原糖收率可达45.135%,糠醛收率可维持在2.35%以下.%The hemicellulose in corn cobs was hydrolyzed for preparing reducing sugars with acetic acid as catalyst. The yields of reducing sugars and furfural were measured in different hydrolysis time under reaction conditions of 160-200 ℃, solid/liquid mass ratio 1 : 15, stirring speed 500 r/min. By using the Garrote model of the hemicellulose hydrolysis with hot liquid water the formation process of reducing sugar was fitted. The results show that the model can better describe the formation of reducing sugar and the degradation of furfural as a by-products. Reducing sugars formation and degradation rate at different hydrolysis temperatures were identified through the curve fitting. At the same time, the hydrolysis activation energy of xylan is 98. 538 kj/mol and the activation energy of reducing sugars degradation is 172 kj/mol determined with Arrhenius equation. Comprehensive comparison of reducing sugars and furfural mass concentrations in hydrolysate at different temperatures indicate that hydrolysis with acetic acid of mass fraction 5% at 180℃ for 19 min are optimum reaction conditions under

  16. Biological hydrolysis and acidification of sludge under anaerobic conditions: The effect of sludge type and origin on the production and composition of olatile fatty acids

    DEFF Research Database (Denmark)

    Ucisik, Ahmed Süheyl; Henze, Mogens

    2008-01-01

    that fermentation of primary sludge produced the highest amount of volatile fatty acids (VFAs) and generated significantly higher COD- and VFA-yields compared to the other sludge types regardless of which WWTP the sludge originated from. Fermentation of activated and primary sludge resulted in 1.9–5.6% and 8....... In this study, the feasibility of implementing biological hydrolysis and acidification process on different types of municipal sludge was investigated by batch and semi-continuous experiments. The municipal sludge originated from six major treatment plants located in Denmark were used. The results showed...... of fermentation for full-scale application was roughly estimated based on the experiments performed in semi-continuous reactors. The results revealed that even though the VFA production of primary sludge was higher compared to activated sludge, substantial amounts of VFA could be produced by fermentation...

  17. The roles of xylan and lignin in oxalic acid pretreated corncob during separate enzymatic hydrolysis and ethanol fermentation

    Science.gov (United States)

    Jae-Won Lee; Rita C.L.B. Rodrigues; Hyun Joo Kim; In-Gyu Choi; Thomas W. Jeffries

    2010-01-01

    High yields of hemicellulosic and cellulosic sugars are critical in obtaining economical conversion of agricultural residues to ethanol. To optimize pretreatment conditions, we evaluated oxalic acid loading rates, treatment temperatures and times in a 23 full factorial design. Response-surface analysis revealed an optimal oxalic acid pretreatment...

  18. In vitro antioxidant and antibacterial properties of hydrolysed proteins of delimed tannery fleshings: comparison of acid hydrolysis and fermentation methods.

    Science.gov (United States)

    Balakrishnan, Bijinu; Prasad, Binod; Rai, Amit Kumar; Velappan, Suresh Puthanveetil; Subbanna, Mahendrakar Namadev; Narayan, Bhaskar

    2011-04-01

    Proteins in delimed tannery fleshings were fermentatively hydrolysed using Enterococcus faecium NCIM5335 and also hydrolysed using mild organic acids (formic acid and propionic acid). The liquor portion containing hydrolysed proteins was spray dried, in both the cases, to obtain a powder. The spray dried powder was evaluated for in vitro antioxidant activities with respect to scavenging different free radicals and antibacterial properties against nine different pathogens. Fermentation and acid hydrolysates scavenged 83 and 75.3% of 2,2-azino-bis-3-ethyl-benzthiazoline-6-sulphonic acid (ABTS) radicals, respectively, at a protein concentration of 0.25 mg. Further, fermentation hydrolysate showed higher 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity of 59% as compared to 56% scavenging by acid hydrolysate at a protein concentration of 5 mg. Acid hydrolysate exhibited lesser (82.3%) peroxy radical scavenging compared to hydrolysate from fermentation (88.2%) at a protein concentration of 10 mg. However, acid hydrolysate exhibited higher (89.2%) superoxide anion scavenging while its fermentation counterpart showed lower activity (85.4%) at 2.5 mg hydrolysate protein. Well as superoxide anion scavenging properties. All the in vitro antioxidant properties exhibited dose dependency. Fermentation hydrolysate exhibited maximum antagonistic activity against Salmonella typhi FB231, from among host of pathogens evaluated. Both the hydrolysates have potential to be ingredients in animal feeds and can help reduce oxidative stress in the animals.

  19. Phytochemical composition and effects of commercial enzymes on the hydrolysis of gallic acid glycosides in mango (Mangifera indica L. cv. 'Keitt') pulp.

    Science.gov (United States)

    Krenek, Kimberly A; Barnes, Ryan C; Talcott, Stephen T

    2014-10-01

    A detailed characterization of mango pulp polyphenols and other minor phytochemicals was accomplished for the first time in the cultivar 'Keitt' whereby the identification and semiquantification of five hydroxybenzoic acids, four cinnamic acids, two flavonoids, and six apocarotenoids was accomplished. Among the most abundant compounds were two monogalloyl glucosides (MGG) identified as having an ester- or ether-linked glucose, with the ester-linked moiety present in the highest concentration among nontannin polyphenolics. Additionally, the impact of side activities of three commercial cell-wall degrading enzymes during 'Keitt' mango pulp processing was evaluated to determine their role on the hydrolysis of ester- and ether-linked phenolic acids. The use of Crystalzyme 200XL reduced the concentration of ester-linked MGG by 66%, and the use of Rapidase AR 2000 and Validase TRL completely hydrolyzed ether-linked MGG after 4 h of treatment at 50 °C. Fruit quality, in vivo absorption rate, and bioactivity of mango phytochemicals rely on their chemical characterization, and characterizing changes in composition is critical for a complete understanding of in vivo mechanisms.

  20. Modeling cereal starch hydrolysis during simultaneous saccharification and lactic acid fermentation; case of a sorghum-based fermented beverage, gowé.

    Science.gov (United States)

    Mestres, Christian; Bettencourt, Munanga de J C; Loiseau, Gérard; Matignon, Brigitte; Grabulos, Joël; Achir, Nawel

    2017-10-01

    Gowé is an acidic beverage obtained after simultaneous saccharification and fermentation (SSF) of sorghum. A previous paper focused on modeling the growth of lactic acid bacteria during gowé processing. This paper focuses on modeling starch amylolysis to build an aggregated SSF model. The activity of α-amylase was modeled as a function of temperature and pH, and the hydrolysis rates of both native and soluble starch were modeled via a Michaelis-Menten equation taking into account the maltose and glucose inhibition constants. The robustness of the parameter estimators was ensured by step by step identification in sets of experiments conducted with different proportions of native and gelatinized starch by modifying the pre-cooking temperature. The aggregated model was validated on experimental data and showed that both the pre-cooking and fermentation parameters, particularly temperature, are significant levers for controlling not only acid and sugar contents but also the expected viscosity of the final product. This generic approach could be used as a tool to optimize the sanitary and sensory quality of fermentation of other starchy products. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. Microwave-assisted extraction (MAE)-acid hydrolysis of dithiocarbamates for trace analysis in tobacco and peaches.

    Science.gov (United States)

    Vryzas, Zisis; Papadakis, Emmanouil N; Papadopoulou-Mourkidou, Euphemia

    2002-04-10

    A simple and rapid method is presented for the analysis of residues of ethylenebis(dithiocarbamate) (maneb, zineb, and mancozeb) and N,N-dimethyldithiocarbamate (thiram and ziram) fungicides in dry tobacco leaves and peaches. Residues are extracted and hydrolyzed to CS(2) in a single step by use of microwave energy in a closed-vessel system while the evolved CS(2) trapped in a layer of iso-octane overlaying the reaction mixture is taken for gas chromatographic-flame photometric analysis. This combined extraction-hydrolysis step is carried out in 10 and 15 min for sets of 12 samples of tobacco and peach matrices, respectively. Total sample preparation time for GC analysis is 40 min. The limits of detection (LOD) are 0.005 mg/kg for thiram and ziram on peaches and 0.1 mg/kg for maneb, zineb, and mancozeb on tobacco. The respective LOD and limit of quantification (LOQ) levels in CS(2) equivalents are 0.003 and 0.006 mg/kg on peaches and 0.04 and 0.2 mg/kg on tobacco, respectively. Recoveries in the 0.01-60 mg/kg fortification range are 80-100% with respective relative standard deviations 3000 commercial tobacco samples including also different marketed cigarette brands.

  2. Hydrolysis of phytic acid by intrinsic plant and supplemented microbial phytase (Aspergillus niger) in the stomach and small intestine of minipigs fitted with re-entrant cannulas. 3. Hydrolysis of phytic acid (IP6) and occurrence of hydrolysis products (IP5, IP4, IP3 and IP2).

    Science.gov (United States)

    Rapp, C; Lantzsch, H J; Drochner, W

    2001-12-01

    Hydrolysis of phytate in the stomach and the small intestine as influenced by intrinsic plant (wheat) and supplemented microbial phytase (Aspergillus niger) were investigated with six minipigs (40-50 kg initial body weight) fitted with re-entrant cannulas in the duodenum, 30 cm posterior to the pylorus (animals 1, 4, 5 and 6) and ileocecal re-entrant cannulas, 5 cm prior the ileocecal junction (animals 1, 2 and 3), respectively. Dietary treatments were as follows: (1) diet 1, a corn-based diet [43 U phytase/kg dry matter (DM)]; (2) diet 2, diet 1 supplemented with microbial phytase (818 U/kg DM); and (3) diet 3, a wheat-based diet (1192 U/kg DM). At 07 30 h and 19 30 h, each animal was fed 350 g diet mixed with 1050 ml de-ionized water. Digesta were collected continuously and completely during a 12-h period after feeding. Mean hydrolysis rates of IP6 in the stomach as measured at the proximal duodenum of animals 1, 4, 5 and 6 were 9.0, 77.2 and 66.2% for diet 1, 2 and 3, respectively. Microbial phytase was much more effective in phytate hydrolysis than wheat phytase. Mean IP6 hydrolysis rates of the respective diets in the stomach and small intestine as measured at the distal ileum of animals 1, 2 and 3 were 19.0, 62.6 and 64.6% and were lower than treatment means of the stomach only. Differences existed between experimental animals with respect to their ability to hydrolyse IP6 in the stomach independent of the presence and source of dietary phytase. Considerable amounts of hydrolysis products occurred in both the duodenal and ileal digesta when diets 2 and 3 were fed; however, only traces were determined after ingestion of diet 1. Independent of dietary treatment, four IP5 isomers were detected, but in different amounts.

  3. Nutritional value of protein hydrolysis products (oligopeptides and free amino acids) as a consequence of absorption and metabolism kinetics

    Science.gov (United States)

    Rerat, A.

    1995-01-01

    When pigs were submitted to duodenal infusion of solutions containing a large percentage of small peptides (PEP) or free amino acids with the same pattern (AAL) amino acids appear in the portal blood more rapidly and more uniformly after infusion of PEP then after infusion of AAL, with the notable exception of methionine for which the opposite was true. These differences were lowered when a carbohydrate (maltose dextrin) was present in the solution, but nevertheless remained significant for the first hour after the infusion. The long-term (8-hour) uptake of free amino acids into the liver and the peripheral tissues differed in profile according to the nature of the duodenal infusion. Peripheral uptake was appreciably less well balanced after infusion of free amino acids (deficiency of threonine and phenylalanine) than after infusion of small peptides (deficiency of methionine). Accordingly, in the rat, under conditions of discontinuous enteral nutrition the mixture of small peptides was of greater nutritive value than the mixture of free amino acids. It thus appears that the absorption kinetics which results in important variations in the temporal distribution of free amino acids in the tissues may be at the origin of transitory imbalances in tissue amino acid uptake, and as a result of a lower nutritive value.

  4. Nutritional value of protein hydrolysis products (oligopeptides and free amino acids) as a consequence of absorption and metabolism kinetics

    Science.gov (United States)

    Rerat, A.

    1995-01-01

    When pigs were submitted to duodenal infusion of solutions containing a large percentage of small peptides (PEP) or free amino acids with the same pattern (AAL) amino acids appear in the portal blood more rapidly and more uniformly after infusion of PEP then after infusion of AAL, with the notable exception of methionine for which the opposite was true. These differences were lowered when a carbohydrate (maltose dextrin) was present in the solution, but nevertheless remained significant for the first hour after the infusion. The long-term (8-hour) uptake of free amino acids into the liver and the peripheral tissues differed in profile according to the nature of the duodenal infusion. Peripheral uptake was appreciably less well balanced after infusion of free amino acids (deficiency of threonine and phenylalanine) than after infusion of small peptides (deficiency of methionine). Accordingly, in the rat, under conditions of discontinuous enteral nutrition the mixture of small peptides was of greater nutritive value than the mixture of free amino acids. It thus appears that the absorption kinetics which results in important variations in the temporal distribution of free amino acids in the tissues may be at the origin of transitory imbalances in tissue amino acid uptake, and as a result of a lower nutritive value.

  5. Enhancement of enzymatic adipyl-7-ADCA hydrolysis

    NARCIS (Netherlands)

    Schroën, C.G.P.H.; Kroon, P.J.; Vanderlaan, J.M.; Janssen, A.E.M.; Tramper, J.

    2002-01-01

    We studied enzymatic adipyl-7-ADCA hydrolysis as a new process for the production of 7-aminodeacetoxycephalosporanic acid (7-ADCA), one of the building blocks for cephalosporin antibiotics like cephalexin and cefadroxil. Adipyl-7-ADCA hydrolysis carried out with immobilised glutaryl acylase was

  6. Structural analysis of lignin by pyrolysis-gas chromatography. 7. Conditions for acid hydrolysis of wood pulp and characteristics of acid-insoluble residues; Netsubunkai gas chromatography ni yoru lignin no kozo kaiseki. 7. Mokuzai pulp no sankasuibunkai joken to sanfuyosei zansa no seijo

    Energy Technology Data Exchange (ETDEWEB)

    Oi, H.; Ju, Y.; Kuroda, K. [The University of Tsukuba, Tsukuba (Japan)

    1997-10-01

    In order to simply analyze lignin present in wood/pulp and the carbohydrate composition, an attempt was made to improve hydrolysis conditions. The tests used pulp samples from degreased akamatsu (Pinus densiflora) meals, akamatsu holocellulose and akamatsu chips. Four methods were tested for acid hydrolysis; the Klason lignin, Yoshiwara, carbohydrate composition and modified carbohydrate composition methods. The acid-insoluble residues were analyzed by pyrolysis-gas chromatography, and the pyrograms prepared under different hydrolysis conditions were compared with each other. The test results indicate that the lignin and composition methods need 2.5h of the primary hydrolysis treatment with 72% sulfuric acid, time of this treatment should be increased to 2.5h for the carbohydrate composition method, and the modified carbohydrate method can quantitatively analyze lignin present in many wood and pulp samples. 7 refs., 6 figs., 3 tabs.

  7. Effectiveness of Alkaline Pretreatment and Acetic Acid Hydrolysis on the Characteristics of Collagen from Fish Skin of Snakehead

    Directory of Open Access Journals (Sweden)

    Wulandari

    2015-12-01

    Full Text Available Fish skin is one of marine byproducts potential for alternative source of collagen. This study investigated the effectiveness of alkaline and acetic acid pretreatment on the characteristics of collagen from skin snakehead fish. The concentrations of alkaline pretreatment were 0.05; 0.1; 0.15 and 0.2 M for 2, 4, 6, 8, 10 and 12 hours, acetic acid concentrations were 0.05 M, 0.1 M, 0.15 M and 0.2 M for 1 and 2 hours. The experimental design used for alkaline and acetic acid pretreatment was factorial completely randomized design. The result showed that the concentration of alkaline 0.05 M for 6 hours have significant effect on the elimination of non-collagen protein (p<0.05, whereas for the optimum acetic acid at a concentration 0.1 M for 2 hours significantly different on solubility and swelling. Extraction yields of collagen was 16%, with characteristics of whiteness 66.67%, protein content 96.21%, viscosity 10 cP, Tmax 159.9oC and glass transition temperature 78.55oC. The dominant amino acid composition were glycine (27.11%, proline (13.87% and alanine (12.58%. Functional groups collagen from skin snakehead fish has β-sheet structure which is a characteristic of collagen.

  8. Effectiveness of Alkaline Pretreatment and Acetic Acid Hydrolysis on the Characteristics of Collagen from Fish Skin of Snakehead

    Directory of Open Access Journals (Sweden)

    Wulandari Wulandari

    2015-12-01

    Full Text Available Fish skin is one of marine byproducts potential for alternative source of collagen. This studyinvestigated the effectiveness of alkaline and acetic acid pretreatment on the characteristics ofcollagen from skin snakehead fish. The concentrations of alkaline pretreatment were 0.05; 0.1; 0.15and 0.2 M for 2, 4, 6, 8, 10 and 12 hours, acetic acid concentrations were 0.05 M, 0.1 M, 0.15 M and0.2 M for 1 and 2 hours. The experimental design used for alkaline and acetic acid pretreatmentwas factorial completely randomized design. The result showed that the concentration of alkaline0.05 M for 6 hours have significant effect on the elimination of non-collagen protein (p<0.05,whereas for the optimum acetic acid at a concentration 0.1 M for 2 hours significantly differenton solubility and swelling. Extraction yields of collagen was 16%, with characteristics of whiteness66.67%, protein content 96.21%, viscosity 10 cP, Tmax 159.9oC and glass transition temperature78.55oC. The dominant amino acid composition were glycine (27.11%, proline (13.87% andalanine (12.58%. Functional groups collagen from skin snakehead fish has β-sheet structurewhich is a characteristic of collagen.

  9. Carbachol induces a rapid and sustained hydrolysis of polyphosphoinositide in bovine tracheal smooth muscle measurements of the mass of polyphosphoinositides, 1,2-diacylglycerol, and phosphatidic acid.

    Science.gov (United States)

    Takuwa, Y; Takuwa, N; Rasmussen, H

    1986-11-05

    The effects of carbachol on polyphosphoinositides and 1,2-diacylglycerol metabolism were investigated in bovine tracheal smooth muscle by measuring both lipid mass and the turnover of [3H]inositol-labeled phosphoinositides. Carbachol induces a rapid reduction in the mass of phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 4-monophosphate and a rapid increase in the mass of 1,2-diacylglycerol and phosphatidic acid. These changes in lipid mass are sustained for at least 60 min. The level of phosphatidylinositol shows a delayed and progressive decrease during a 60-min period of carbachol stimulation. The addition of atropine reverses these responses completely. Carbachol stimulates a rapid loss in [3H]inositol radioactivity from phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 4-monophosphate associated with production of [3H]inositol trisphosphate. The carbachol-induced change in the mass of phosphoinositides and phosphatidic acid is not affected by removal of extracellular Ca2+ and does not appear to be secondary to an increase in intracellular Ca2+. These results indicate that carbachol causes phospholipase C-mediated polyphosphoinositide breakdown, resulting in the production of inositol trisphosphate and a sustained increase in the actual content of 1,2-diacylglycerol. These results strongly suggest that carbachol-induced contraction is mediated by the hydrolysis of polyphosphoinositides with the resulting generation of two messengers: inositol 1,4,5-trisphosphate and 1,2-diacylglycerol.

  10. Carbachol induces a rapid and sustained hydrolysis of polyphosphoinositide in bovine tracheal smooth muscle measurements of the mass of polyphosphoinositides, 1,2-diacylglycerol, and phosphatidic acid

    Energy Technology Data Exchange (ETDEWEB)

    Takuwa, Y.; Takuwa, N.; Rasmussen, H.

    1986-11-05

    The effects of carbachol on polyphosphoinositides and 1,2-diacylglycerol metabolism were investigated in bovine tracheal smooth muscle by measuring both lipid mass and the turnover of (/sup 3/H)inositol-labeled phosphoinositides. Carbachol induces a rapid reduction in the mass of phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 4-monophosphate and a rapid increase in the mass of 1,2-diacylglycerol and phosphatidic acid. These changes in lipid mass are sustained for at least 60 min. The level of phosphatidylinositol shows a delayed and progressive decrease during a 60-min period of carbachol stimulation. The addition of atropine reverses these responses completely. Carbachol stimulates a rapid loss in (/sup 3/H)inositol radioactivity from phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 4-monophosphate associated with production of (/sup 3/H)inositol trisphosphate. The carbachol-induced change in the mass of phosphoinositides and phosphatidic acid is not affected by removal of extracellular Ca/sup 2 +/ and does not appear to be secondary to an increase in intracellular Ca/sup 2 +/. These results indicate that carbachol causes phospholipase C-mediated polyphosphoinositide breakdown, resulting in the production of inositol trisphosphate and a sustained increase in the actual content of 1,2-diacylglycerol. These results strongly suggest that carbachol-induced contraction is mediated by the hydrolysis of polyphosphoinositides with the resulting generation of two messengers: inositol 1,4,5-trisphosphate and 1,2-diacylglycerol.

  11. Synthesis of fluorescent carbon dots via simple acid hydrolysis of bovine serum albumin and its potential as sensitive sensing probe for lead (II) ions.

    Science.gov (United States)

    Wee, Shui Shui; Ng, Yann Huey; Ng, Sing Muk

    2013-11-15

    Carbon dots have great potential to be utilised as an optical sensing probe due to its unique photoluminescence and less toxic properties. This work reports a simple and novel synthesis method of carbon dots via direct acid hydrolysis of bovine serum albumin protein in a one-pot approach. Optimisation of the important synthetic parameters has been performed which consists of temperature effect, acid to protein ratio and kinetics of reaction. Higher temperature has promoted better yield with shorter reaction time. The carbon dots obtained shows a strong emission at the wavelength of 400 nm with an optimum excitation of 305 nm. The potential of the carbon dots as optical sensing probe has been investigated on with different cations that are of environmental and health concern. The fluorescence of the carbon dots was significantly quenched particularly by lead (II) ions in a selective manner. Further analytical study has been performed to leverage the performance of the carbon dots for lead (II) ions sensing using the standard Stern-Volmer relationship. The sensing probe has a dynamic linear range up to 6.0 mM with a Stern-Volmer constant of 605.99 M(-1) and a limit of detection (LOD) of 5.05 μM. The probe performance was highly repeatable with a standard deviation below 3.0%. The probe suggested in this study demonstrates the potential of a more economical and greener approach that uses protein based carbon dots for sensing of heavy metal ions.

  12. SYNTHESIS OF CONDENSATION POLYMERS OF SALICYLIC ACID, FORMALDEHYDE AND ALKYL PRIMARY AMINES AND ITS APPLICATION AS A CATALYST FOR THE HYDROLYSIS OF p-NITROPHENYL ACETATE (PNPA) IN AQUEOUS SOLUTION

    Institute of Scientific and Technical Information of China (English)

    HE Binglin(Ho Pinglum); HUANG Wenqiang

    1983-01-01

    As a model of serine hydrolase, the condensation polymers of salicylic acid, formaldehyde and methyl amine, n-propyl amine, n-hexyl amine or n-lauryl amine were prepared by polycondensation catalyzed by sulfuric acid. It was confirmed by potentiometric titration and infrared spectrum that the polymers containing tertiary amino group possess the structure which resembles the internal salt of amino acid in weak basic and weak acidic solution:[-OOC-OH-CH2-H+N-R-CH2-]n R=alkyl group The catalytic reaction of the above polymers for hydrolysis of active ester,p-nitrophenyl acetate (PNPA),was studied .It was found kinetically that the most efficient catalytic effect of polymer was composed of two salicylic acid groups and one tertiary amino group in the polymer chain.The rates of hydrolysis of PNPA increase with increasing of pH values and length of the alkyl group in the side chain of the polymers and the effect of the conformation of the polymer containing tertiary amino group in the buffer solution on the catalytic activity was also investigated. Hydrolysis of PNPA catalyzed by the polymer made of salicylic acid, formaldehyde and n-lauryl amine follows the simple Michaelis-Menten type mechanism . The kinetics parameters were determined as :Km 6.7×10-5 M and Vmax 2.07×10-7 M·min-1.

  13. Hydrolysis kinetics of atrazine and influence factors

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The hydrolysis kinetics of atrazine in distilled water and leaching water from soil, and their influence factors were studied by incubation at 35℃ and HPLC analysis method in this paper. The kinetic process of atrazine hydrolysis can be described by the first-order reaction law. The results showed that the hydrolysis rate constants k in leaching water and distilled water were 1.606x10-3/d and 1.055x10-3/d, respectively; the half-life of atrazine hydrolysis in distilled water at pH 3, pH 4.5 and pH 8 were 373 days, 522 days and 657 days respectively. The results also showed that the proton in reaction solution can catalyze the atrazine hydrolysis; humic acid and NH4+ etc. substances in aqueous solution can facilitate atrazine hydrolysis; rate constants of atrazine hydrolysis with humic acid and NH4NO3 were 2.431x10-3/d and 1.498x10-3/d respectively which were 2.3 and 1.42 times of control(1.055x10-3/d); anion NO3- can inhibit catalysis of humic acid to atrazine hydrolysis.

  14. Bench scale steam explosion pretreatment of acid impregnated elephant grass biomass and its impacts on biomass composition, structure and hydrolysis

    NARCIS (Netherlands)

    Kataria, Rashmi; Mol, Annemerel; Schulten, Els; Happel, Anton; Mussatto, Solange I.

    2017-01-01

    In the present study, an acid mediated steam explosion process was evaluated for pretreatment of elephant grass biomass in a bench scale reactor. Different combinations of H2SO4 concentration, reaction time and temperature (leading to different values of combined severity factor - CSF) were used for

  15. Bench scale steam explosion pretreatment of acid impregnated elephant grass biomass and its impacts on biomass composition, structure and hydrolysis

    NARCIS (Netherlands)

    Kataria, Rashmi; Mol, Annemerel; Schulten, Els; Happel, Anton; Mussatto, Solange I.

    2016-01-01

    In the present study, an acid mediated steam explosion process was evaluated for pretreatment of elephant grass biomass in a bench scale reactor. Different combinations of H2SO4 concentration, reaction time and temperature (leading to different values of combined severity fa

  16. Analytical pyrolysis and thermally assisted hydrolysis and methylation of EUROSOIL humic acid samples: a key to their source

    NARCIS (Netherlands)

    Buurman, P.; Nierop, K.G.J.; Kaal, J.; Senesi, S.I.

    2009-01-01

    Humic acids have been widely investigated by spectroscopic methods, especially NMR and FTIR, and they are known to show significant differences according to their origin. Low resolution methods such as NMR and FTIR, however cannot easily distinguish different input sources or establish relations bet

  17. Response surface optimization of corn stover pretreatment using dilute phosphoric acid for enzymatic hydrolysis and ethanol production

    Science.gov (United States)

    Dilute H3PO4 (0.0 - 2.0%, v/v) was used to pretreat corn stover (10%, w/w) for conversion to ethanol. Pretreatment conditions were optimized for temperature, acid loading, and time using a central composite design. Optimal pretreatment conditions were chosen to promote sugar yields following enzym...

  18. The effect of cathodic polarisation on monosaccharides of Amphora coffeaeformis, a marine fouling diatom

    Digital Repository Service at National Institute of Oceanography (India)

    Bhosle, N.B.; Evans, L.V.; Edyvean, R.G.J.

    , concentrations of monosaccharides were higher by a factor of 8 to 40 in A. coffeaeformis cells attached to non-polarised steel. The abundance of monosaccharides increased over the period of cultivation in the cells on non-polarised steel. Eight individual...

  19. Continuous steam hydrolysis of tulip poplar

    Energy Technology Data Exchange (ETDEWEB)

    Fieber, C.A.; Roberts, R.S.; Faass, G.S.; Muzzy, J.D.; Colcord, A.R.; Bery, M.K.

    1982-01-01

    The continuous hydrolysis of poplar chips by steam at 300-350 psi resulted in the separation of hemicellulose (I) cellulose and lignin components. The I fraction was readily depolymerised by steam to acetic acid, furfural, methanol, and xylose.

  20. The integration of dilute acid hydrolysis of xylan and fast pyrolysis of glucan to obtain fermentable sugars

    OpenAIRE

    Jiang, Liqun; Wu, Nannan; Zheng, Anqing; Zhao, Zengli; He, Fang; Li, Haibin

    2016-01-01

    Background Fermentable sugars are important intermediates in the biological conversion of biomass. Hemicellulose and amorphous cellulose are easily hydrolyzed to fermentable sugars in dilute acid, whereas crystalline cellulose is more difficult to be hydrolyzed. Cellulose fast pyrolysis is an alternative method to liberate valuable fermentable sugars from biomass. The amount of levoglucosan generated from lignocellulose by fast pyrolysis is usually lower than the theoretical yield based on th...

  1. Specific rotation as a property to validate monosaccharide conformations.

    Science.gov (United States)

    Andrade, Renato R; da Silva, Clarissa O

    2012-03-01

    Specific rotation ([α](D)) values were calculated for the 15 conformations of xylopyranose that are the most stable in the gas phase and in aqueous solution. The effects of different theoretical descriptions and the medium on the geometry of the conformers and the [α](D) values are evaluated. Differences in [α](D) values found for the same conformer in all descriptions used were smaller than those found between any two different conformers in the same description. The difference between [α](D) values is prominent, even for two conformations that are distinguished from each other only by the orientation of one secondary hydroxyl group. This finding suggests that [α](D) values may potentially be used in the validation of monosaccharide conformations that are theoretically sampled. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. Molecular Weight and Monosaccharide Composition of Astragalus Polysaccharides

    Directory of Open Access Journals (Sweden)

    Pei-Pei Wang

    2008-10-01

    Full Text Available Two polysaccharides (APS-I and APS-II were isolated from the water extract of Radix Astragali and purified through ethanol precipitation, deproteination and by ion-exchange and gel-filtration chromatography. Their molecular weight was determined using high performance liquid chromatography and gel permeation chromatography (HPLC-GPC and their monosaccharide composition was analyzed by TLC and HPLC methods, using a refractive index detector (RID and an NH2 column. It was shown that APS-I consisted of arabinose and glucose and APS-II consisted of rhamnose, arabinose and glucose, in a molar ratio of 1:3.45 and 1:6.25:17.86, respectively. The molecular weights (Mw of APS-I and APS-II were 1,699,100 Da and 1,197,600 Da, respectively.

  3. Peanut Shell-Derived Carbon Solid Acid with Large Surface Area and Its Application for the Catalytic Hydrolysis of Cyclohexyl Acetate

    Directory of Open Access Journals (Sweden)

    Wei Xue

    2016-10-01

    Full Text Available A carbon solid acid with large surface area (CSALA was prepared by partial carbonization of H3PO4 pre-treated peanut shells followed by sulfonation with concentrated H2SO4. The structure and acidity of CSALA were characterized by N2 adsorption–desorption, scanning electron microscopy (SEM, X-ray powder diffraction (XRD, 13C cross polarization (CP/magic angle spinning (MAS nuclear magnetic resonance (NMR, X-ray photoelectron spectroscopy (XPS, Fourier transform-infrared spectroscopy (FT-IR, titration, and elemental analysis. The results demonstrated that the CSALA was an amorphous carbon material with a surface area of 387.4 m2/g. SO3H groups formed on the surface with a density of 0.46 mmol/g, with 1.11 mmol/g of COOH and 0.39 mmol/g of phenolic OH. Densities of the latter two groups were notably greater than those observed on a carbon solid acid (CSA with a surface area of 10.1 m2/g. The CSALA catalyst showed better performance than the CSA for the hydrolysis of cyclohexyl acetate to cyclohexanol. Under optimal reaction conditions, cyclohexyl acetate conversion was 86.6% with 97.3% selectivity for cyclohexanol, while the results were 25.0% and 99.4%, respectively, catalyzed by CSA. The high activity of the CSALA could be attributed to its high density of COOH and large surface area. Moreover, the CSALA showed good reusability. Its catalytic activity decreased slightly during the first two cycles due to the leaching of polycyclic aromatic hydrocarbon-containing SO3H groups, and then remained constant during following uses.

  4. A monosaccharide transporter is localized to sieve plate and plasmodesmal channel in developing apple fruit

    Institute of Scientific and Technical Information of China (English)

    ZHANG Lingyun; PENG Changcao; ZOU Keqin; WANG Xiuling; FAN Renchun; YU Xiangchun; ZHANG Xiaoyan; SHEN Yuanyue; ZHANG Dapeng

    2005-01-01

    Two major classes of plant sugar transporters, sucrose and monosaccharide transporters, may be localized to tonoplast or plasma membrane. The monosaccharide transporters may also be localized in plastid. However, whether these transporters reside in other subcellular compartments remains unclear. We recently detected in apple fruit a 52 kD plasma membrane-localized monosaccharide transporter, and showed that this transporter may be functional in phloem unloading in the fruit. In this paper, we report that this monosaccharide transporter is also localized to sieve plate and plasmodesmal channel in apple fruit. The amount of this sieve plate- and plasmodesma-associated transporter changes during fruit development. This amount of the transporter expression may be altered in the phloem sieve elements but not in the parenchyma cells by a photoassimilate deficiency applied by the shoot girdling treatment, suggesting that the monosaccharide transporter of the special sub-cellular localization may be of biological significance.

  5. Optimization of the Process of Furfural Preparation via Catalytic Hydrolysis of Corncob by Acid Salt%酸式盐催化玉米芯水解制取糠醛的工艺优化

    Institute of Scientific and Technical Information of China (English)

    冯培良; 王君; 李多松; 严丽

    2014-01-01

    针对工业生产中采用稀硫酸催化玉米芯水解制备糠醛存在催化剂毒性大、腐蚀及污染严重等问题,本研究尝试采用酸式盐催化玉米芯水解制备糠醛。通过单因素试验研究了催化剂种类、反应时间、反应温度对糠醛得率的影响。确定了制取糠醛的最佳工艺条件为硫酸氢钠作催化剂、反应时间90 min、反应温度190℃,此条件下糠醛的得率达39.91%。%Aiming at the existing problems such as high toxicity, severe corrosion and pollution of dilute sulfuric acid as catalyst for furfural preparation in present industry, this study attempted to prepare furfural via hydrolysis of corncob using acid salt as catalyst. The effects of catalysts type, reaction temperature, reaction time on furfural yield were investigated through single factor experiments. The optimum hydrolysis technology parameters for producing furfural were obtained as follows:hydrolysis time of 90 min, hydrolysis temperature of 190℃ and sodium hydrogen sulfate as catalyst,. Under this condition, the furfural yield reached 39.91%.

  6. Statistical Optimization for Acid Hydrolysis of Microcrystalline Cellulose and Its Physiochemical Characterization by Using Metal Ion Catalyst

    Directory of Open Access Journals (Sweden)

    Md. Ziaul Karim

    2014-10-01

    Full Text Available Hydrolyzing the amorphous region while keeping the crystalline region unaltered is the key technology for producing nanocellulose. This study investigated if the dissolution properties of the amorphous region of microcrystalline cellulose can be enhanced in the presence of Fe3+ salt in acidic medium. The process parameters, including temperature, time and the concentration of metal chloride catalyst (FeCl3, were optimized by using the response surface methodology (RSM. The experimental observation demonstrated that temperature and time play vital roles in hydrolyzing the amorphous sections of cellulose. This would yield hydrocellulose with higher crystallinity. The factors that were varied for the production of hydrocellulose were the temperature (x1, time (x2 and FeCl3 catalyst concentration (x3. Responses were measured in terms of percentage of crystallinity (y1 and the yield (y2 of the prepared hydrocellulose. Relevant mathematical models were developed. Analysis of variance (ANOVA was carried out to obtain the most significant factors influencing the responses of the percentage of crystallinity and yield. Under optimum conditions, the percentage of crystallinity and yield were 83.46% and 86.98% respectively, at 90.95 °C, 6 h, with a catalyst concentration of 1 M. The physiochemical characteristics of the prepared hydrocellulose were determined in terms of XRD, SEM, TGA and FTIR analyses. The addition of FeCl3 salt in acid hydrolyzing medium is a novel technique for substantially increasing crystallinity with a significant morphological change.

  7. Optimization of hydrolysis and volatile fatty acids production from sugarcane filter cake: Effects of urea supplementation and sodium hydroxide pretreatment.

    Science.gov (United States)

    Janke, Leandro; Leite, Athaydes; Batista, Karla; Weinrich, Sören; Sträuber, Heike; Nikolausz, Marcell; Nelles, Michael; Stinner, Walter

    2016-01-01

    Different methods for optimization the anaerobic digestion (AD) of sugarcane filter cake (FC) with a special focus on volatile fatty acids (VFA) production were studied. Sodium hydroxide (NaOH) pretreatment at different concentrations was investigated in batch experiments and the cumulative methane yields fitted to a dual-pool two-step model to provide an initial assessment on AD. The effects of nitrogen supplementation in form of urea and NaOH pretreatment for improved VFA production were evaluated in a semi-continuously operated reactor as well. The results indicated that higher NaOH concentrations during pretreatment accelerated the AD process and increased methane production in batch experiments. Nitrogen supplementation resulted in a VFA loss due to methane formation by buffering the pH value at nearly neutral conditions (∼ 6.7). However, the alkaline pretreatment with 6g NaOH/100g FCFM improved both the COD solubilization and the VFA yield by 37%, mainly consisted by n-butyric and acetic acids.

  8. Centrifugal partition chromatography in a biorefinery context: Optimisation and scale-up of monosaccharide fractionation from hydrolysed sugar beet pulp.

    Science.gov (United States)

    Ward, David P; Hewitson, Peter; Cárdenas-Fernández, Max; Hamley-Bennett, Charlotte; Díaz-Rodríguez, Alba; Douillet, Nathalie; Adams, Joseph P; Leak, David J; Ignatova, Svetlana; Lye, Gary J

    2017-05-12

    The isolation of component sugars from biomass represents an important step in the bioprocessing of sustainable feedstocks such as sugar beet pulp. Centrifugal partition chromatography (CPC) is used here, as an alternative to multiple resin chromatography steps, to fractionate component monosaccharides from crude hydrolysed sugar beet pulp pectin. CPC separation of samples, prepared in the stationary phase, was carried out using an ethanol: ammonium sulphate (300gL(-1)) phase system (0.8:1.8v:v) in ascending mode. This enabled removal of crude feedstream impurities and separation of monosaccharides into three fractions (l-rhamnose, l-arabinose and d-galactose, and d-galacturonic acid) in a single step. Throughput was improved three-fold by increasing sample injection volume, from 4 to 16% of column volume, with similar separation performance maintained in all cases. Extrusion of the final galacturonic acid fraction increased the eluted solute concentration, reduced the total separation time by 24% and removed the need for further column regeneration. Reproducibility of the separation after extrusion was validated by using multiple stacked injections. Scale-up was performed linearly from a semi-preparative 250mL column to a preparative 950mL column with a scale-up ratio of 3.8 applied to mobile phase flow rate and sample injection volume. Throughputs of 9.4gL(-1)h(-1) of total dissolved solids were achieved at the preparative scale with a throughput of 1.9gL(-1)h(-1) of component monosaccharides. These results demonstrate the potential of CPC for both impurity removal and target fractionation within biorefinery separations. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  9. Acid Hydrolysis of Wheat Gluten Induces Formation of New Epitopes but Does Not Enhance Sensitizing Capacity by the Oral Route: A Study in “Gluten Free” Brown Norway Rats

    Science.gov (United States)

    Kroghsbo, Stine; Andersen, Nanna B.; Rasmussen, Tina F.; Madsen, Charlotte B.

    2014-01-01

    Background Acid hydrolyzed wheat proteins (HWPs) are used in the food and cosmetic industry as emulsifiers. Cases of severe food allergic reactions caused by HWPs have been reported. Recent data suggest that these reactions are caused by HWPs produced by acid hydrolysis. Objectives To examine the sensitizing capacity of gluten proteins per se when altered by acid or enzymatic hydrolysis relative to unmodified gluten in rats naïve to gluten. Methods High IgE-responder Brown Norway (BN) rats bred on a gluten-free diet were sensitized without the use of adjuvant to three different gluten products (unmodified, acid hydrolyzed and enzymatic hydrolyzed). Rats were sensitized by intraperitoneal (i.p.) immunization three times with 200 µg gluten protein/rat or by oral dosing for 35 days with 0.2, 2 or 20 mg gluten protein/rat/day. Sera were analyzed for specific IgG and IgE and IgG-binding capacity by ELISA. IgE functionality was measured by rat basophilic leukemia (RBL) assay. Results Regardless of the route of dosing, all products had sensitizing capacity. When sensitized i.p., all three gluten products induced a strong IgG1 response in all animals. Acid hydrolyzed gluten induced the highest level of specific IgE but with a low functionality. Orally all three gluten products induced specific IgG1 and IgE but with different dose-response relations. Sensitizing rats i.p. or orally with unmodified or enzymatic hydrolyzed gluten induced specific IgG1 responses with similar binding capacity which was different from that of acid hydrolyzed gluten indicating that acid hydrolysis of gluten proteins induces formation of ‘new’ epitopes. Conclusions In rats not tolerant to gluten acid hydrolysis of gluten enhances the sensitizing capacity by the i.p. but not by the oral route. In addition, acid hydrolysis induces formation of new epitopes. This is in contrast to the enzymatic hydrolyzed gluten having an epitope pattern similar to unmodified gluten. PMID:25207551

  10. Evaluation of soluble fraction and enzymatic residual fraction of dilute dry acid, ethylenediamine, and steam explosion pretreated corn stover on the enzymatic hydrolysis of cellulose.

    Science.gov (United States)

    Qin, Lei; Liu, Li; Li, Wen-Chao; Zhu, Jia-Qing; Li, Bing-Zhi; Yuan, Ying-Jin

    2016-06-01

    This study is aimed to examine the inhibition of soluble fraction (SF) and enzymatic residual fraction (ERF) in dry dilute acid (DDA), ethylenediamine (EDA) and steam explosion (SE) pretreated corn stover (CS) on the enzymatic digestibility of cellulose. SF of DDA, EDA and SE pretreated CS has high xylose, soluble lignin and xylo-oligomer content, respectively. SF of EDA pretreated CS leads to the highest inhibition, followed by SE and DDA pretreated CS. Inhibition of ERF of DDA and SE pretreated CS is higher than that of EDA pretreated CS. The inhibition degree (A0/A) of SF is 1.76 and 1.21 times to that of ERF for EDA and SE pretreated CS, respectively. The inhibition degree of ERF is 1.05 times to that of SF in DDA pretreated CS. The quantitative analysis shows that SF of EDA pretreated CS, SF and ERF of SE pretreated CS cause significant inhibition during enzymatic hydrolysis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  11. Fundamental study of the mechanism and kinetics of cellulose hydrolysis by acids and enzymes. Progress report, June 1, 1975--December 31, 1975

    Energy Technology Data Exchange (ETDEWEB)

    Tsao, G T

    1976-02-01

    This project deals with acidic and enzymatic hydrolysis of cellulosic materials. Highlights of the first eight months of out project are as follows. (1) Essentially homogeneous C/sub 1/, C/sub x/, and Cellobiase enzyme have been isolated from Cellulase-Onozuka of Trichodeima viride origin. Besides the 3 major components, one protein of a molecular weight of 10,000 was purified, which has strong C/sub x/ activity and also another (M.W. 23,000) with strong C/sub 1/ activity. (2) Kinetics of Cellobiase has been investigated and its kinetics constant accurately determined. Immobilization of this enzyme on porous glass was successful. (3) Absorption of SO/sub 2/ at atmospheric pressure increased digestibility of delignated cellulose but not the natural materials such as corn stalk. A pressurizable absorption unit is being built. (4) Kinetics models for purified C/sub 1/ and C/sub x/ are postulated and equations derived. Experimental tests will be made when sufficient quantities of purified C/sub 1/ and C/sub x/ enzyme are prepared. (5) A lignin digesting, white-rot fungus, Pleurotus ostreatus, has cultivated in our laboratory. It has grown well and heavy. (6) A number of electron micrographs were made with untreated cellulosic materials, which showed that the method of drying the specimens for electromicroscopy is important. Ordinary drying procedures will alter their physical structures. A technique, critical point drying, is being practiced, which will not change the structure. (auth)

  12. Production of volatile fatty acids by fermentation of waste activated sludge pre-treated in full-scale thermal hydrolysis plants.

    Science.gov (United States)

    Morgan-Sagastume, F; Pratt, S; Karlsson, A; Cirne, D; Lant, P; Werker, A

    2011-02-01

    This work focuses on fermentation of pre-treated waste activated sludge (WAS) to generate volatile fatty acids (VFAs). Pre-treatment by high-pressure thermal hydrolysis (HPTH) was shown to aid WAS fermentation. Compared to fermentation of raw WAS, pre-treatment enabled a 2-5x increase in VFA yield (gVFA(COD)gTCOD(-1)) and 4-6x increase in VFA production rate (gVFA(COD) L(-1) d(-1)). Three sludges, pre-treated in full-scale HPTH plants, were fermented. One was from a plant processing a mix of primary sludge and WAS and the other two from plants processing solely WAS. The HPTH plants solubilised suspended matter, evidenced by a 20-30% decrease in suspended solids and an increase of soluble COD : total COD from 0.04 to 0.4. Fermentation of the three sludges yielded similar VFA concentrations (15-20gVFA(COD) L(-1)). The yields were largely independent of retention time (1 d-6 d) and temperature (42°C, 55°C). Also, the product spectrum depended mostly on the composition of the sludge rather than on operating conditions.

  13. Development of microwave-assisted acid hydrolysis of proteins using a commercial microwave reactor and its combination with LC-MS for protein full-sequence analysis.

    Science.gov (United States)

    Chen, Lu; Wang, Nan; Li, Liang

    2014-11-01

    Microwave-assisted acid hydrolysis (MAAH) can be used to degrade a protein non-specifically into many peptides with overlapping sequences which can be identified by mass spectrometry (MS) to produce a sequence map that covers the full sequence of a protein. The success of this method for protein sequence analysis depends on the proper control of the MAAH process, which is currently done using a household microwave oven. However, to meet the regulatory or good laboratory practice (GLP) requirement in a clinical or pharmaceutical laboratory, using a commercial microwave device is often required. In this paper, we report a method of performing MAAH using a CEM Discover single-mode microwave reactor. It is shown that, using an optimized protocol for MAAH, reproducible results comparable to those obtained using a household microwave oven can be generated using the commercial reactor. To illustrate the potential applications of MAAH MS for characterizing clinically relevant proteins, this method was applied, for the first time, to map the amino acid sequences of normal and sickle-cell human hemoglobin as well as bovine hemoglobin. Full sequence coverage was readily achieved from 294 and 266 unique peptides matched to the alpha and beta subunits of normal hemoglobin, respectively, 334 and 265 unique peptides matched to the alpha and beta submit units of sickle-cell hemoglobin, and 377 and 224 unique peptides matched to the alpha and beta subunits of bovine hemoglobin. This method opens the possibility for any laboratory to use a commercial laboratory equipment to perform MAAH MS for protein full-sequence analysis.

  14. Study the Effect of Hydrolysis Variables on the Production of Soya Proteins Hydrolysis

    Directory of Open Access Journals (Sweden)

    Sundus H.Ahammed

    2009-01-01

    Full Text Available This study was conducted to determine the effects of concentration of hydrochloric acids, temperature, and time on the hydrolysis of soya proteins (defatted soya flour by determining the value of total protein nitrogen concentration, and amino nitrogen concentration of protein, peptides, and amino acids, and then calculated the hydrolysis rate of proteins.The variables of the conditions of hydrolysis process was achieved in this study with the following range value of tests parameter: •Concentration of HCl solution ranged between 1-7 N, •Hydrolysis temperature ranged between 35-95 C, and•The time of hydrolysis period ranged between 0.5-24 hr.Experiments were designed according to the central composite rotatable design.The practical study has shown the possibility of decreasing the negative effect of the acid on the biological characteristics of the protein; then affecting the possibility of using the product for biological purposes (for medical and microbiological laboratories by:•Decreasing the acid concentration used in the process of hydrolysis, firstly, and •Decreasing the temperature of the hydrolysis process, secondly, and then •Increasing the period of the time of hydrolysis process, thirdly.

  15. Molecular cloning and expression analysis of a monosaccharide transporter gene OsMST4 from rice (Oryza sativa L.)

    NARCIS (Netherlands)

    Wang, Y.; Xu, H.; Wei, X.; Chai, C.; Xiao, Y.; Zhang, Y.; Chen, B.; Xiao, G.; Ouwerkerk, P.B.F.; Wang, M.; Zhu, Z.

    2007-01-01

    Monosaccharide transporters mediate the membrane transport of a variable range of monosaccharides, which plays a crucial role in sugar distribution throughout the plant. To investigate the significance of monosaccharide transporters for rice (Oryza sativa L.) seed development, cDNA of a new putative

  16. Promoter activity of a putative pollen monosaccharide transporter in Petunia hybrida and characterisation of a transposon insertion mutant

    NARCIS (Netherlands)

    Garrido, D.; Busscher-Lange, J.; Tunen, van A.J.

    2006-01-01

    For the growth of the male reproductive cells of plants, the pollen, the presence of sufficient sucrose or monosaccharides is of vital importance. From Petunia hybrida a pollen-specific putative monosaccharide transporter designated PMT1 (for petunia monosaccharide transporter) has been identified p

  17. Hemicellulases and auxiliary enzymes for improved conversion of lignocellulosic biomass to monosaccharides

    Directory of Open Access Journals (Sweden)

    Hermanson Spencer

    2011-02-01

    Full Text Available Abstract Background High enzyme loading is a major economic bottleneck for the commercial processing of pretreated lignocellulosic biomass to produce fermentable sugars. Optimizing the enzyme cocktail for specific types of pretreated biomass allows for a significant reduction in enzyme loading without sacrificing hydrolysis yield. This is especially important for alkaline pretreatments such as Ammonia fiber expansion (AFEX pretreated corn stover. Hence, a diverse set of hemicellulases supplemented along with cellulases is necessary for high recovery of monosaccharides. Results The core fungal cellulases in the optimal cocktail include cellobiohydrolase I [CBH I; glycoside hydrolase (GH family 7A], cellobiohydrolase II (CBH II; GH family 6A, endoglucanase I (EG I; GH family 7B and β-glucosidase (βG; GH family 3. Hemicellulases tested along with the core cellulases include xylanases (LX1, GH family 10; LX2, GH family 10; LX3, GH family 10; LX4, GH family 11; LX5, GH family 10; LX6, GH family 10, β-xylosidase (LβX; GH family 52, α-arabinofuranosidase (LArb, GH family 51 and α-glucuronidase (LαGl, GH family 67 that were cloned, expressed and/or purified from different bacterial sources. Different combinations of these enzymes were tested using a high-throughput microplate based 24 h hydrolysis assay. Both family 10 (LX3 and family 11 (LX4 xylanases were found to most efficiently hydrolyze AFEX pretreated corn stover in a synergistic manner. The optimal mass ratio of xylanases (LX3 and LX4 to cellulases (CBH I, CBH II and EG I is 25:75. LβX (0.6 mg/g glucan is crucial to obtaining monomeric xylose (54% xylose yield, while LArb (0.6 mg/g glucan and LαGl (0.8 mg/g glucan can both further increase xylose yield by an additional 20%. Compared with Accellerase 1000, a purified cocktail of cellulases supplemented with accessory hemicellulases will not only increase both glucose and xylose yields but will also decrease the total enzyme loading

  18. Bioethanol Production from Paper Fibre Residue Using Diluted Alkali Hydrolysis and the Fermentation Process

    Directory of Open Access Journals (Sweden)

    G. Sathya Geetha

    2011-01-01

    Full Text Available The state of art for the bioethanol production from paper fibre residue using diluted alkali hydrolysis and fermentation processes was evaluated. Hydrolysis of paper fibre residue with diluted sodium hydroxide at various time period, temperature and concentration were investigated. The paper fibre residue was pre-steamed, impregnated with diluted NaOH (0 to 25% and subsequently hydrolyzed in a reactor at temperatures that ranged between 30 to 50 oC, for reaction time between 30 minutes to 150 minutes. The highest yield of monosaccharide (indicating the efficient hydrolysis of cellulose and hemi cellulose was found at a temperature of 35 oC for a reaction time of 90 minutes. Fermentability of hemicelluloses hydrolysate was tested using monosaccharide fermenting microorganism Penicillium chrysogenum and Saccharomyces cereviacea. The fermentability of the hydrolysate decreased strongly for hydrolysate produced at temperature higher than 50 oC. The ethanol concentration of monosaccharide hydrolysate was found to be 34.06 g/L and the ethanol yield was 0.097 g/g.

  19. Ab initio molecular simulations on specific interactions between amyloid beta and monosaccharides

    Science.gov (United States)

    Nomura, Kazuya; Okamoto, Akisumi; Yano, Atsushi; Higai, Shin'ichi; Kondo, Takashi; Kamba, Seiji; Kurita, Noriyuki

    2012-09-01

    Aggregation of amyloid β (Aβ) peptides, which is a key pathogenetic event in Alzheimer's disease, can be caused by cell-surface saccharides. We here investigated stable structures of the solvated complexes of Aβ with some types of monosaccharides using molecular simulations based on protein-ligand docking and classical molecular mechanics methods. Moreover, the specific interactions between Aβ and the monosaccharides were elucidated at an electronic level by ab initio fragment molecular orbital calculations. Based on the results, we proposed which type of monosaccharide prefers to have large binding affinity to Aβ and inhibit the Aβ aggregation.

  20. Enthalpy and entropy interaction parameters of sodium chloride with some monosaccharides in water

    Institute of Scientific and Technical Information of China (English)

    ZHUO; Kelei; WANG; Jianji; BAI; Guangyue; YAN; Haike; WANG

    2004-01-01

    Dilution enthalpies of sodium chloride and some monosaccharides (glucose, galactose, xylose, arabinose, and fructose) in water and mixing enthalpies of aqueous sodium chloride and these monosaccharide solutions were measured by using an improved precision semimicro-titration calorimeter. Transfer enthalpies of sodium chloride from water to aqueous saccharide solutions were evaluated as well as enthalpy interaction parameters of sodium chloride with these monosaccharides in water. Combined with Gibbs energy interaction parameters, entropy interaction parameters were also obtained. The results show that interactions of the saccharides with sodium chloride depend on the stereochemistry of saccharide molecules. These interaction parameters can identify stereochemical structure of saccharide molecules.

  1. Comparative study of corn stover pretreated by dilute acid and cellulose solvent-based lignocellulose fractionation: Enzymatic hydrolysis, supramolecular structure, and substrate accessibility.

    Science.gov (United States)

    Zhu, Zhiguang; Sathitsuksanoh, Noppadon; Vinzant, Todd; Schell, Daniel J; McMillan, James D; Zhang, Y-H Percival

    2009-07-01

    Liberation of fermentable sugars from recalcitrant biomass is among the most costly steps for emerging cellulosic ethanol production. Here we compared two pretreatment methods (dilute acid, DA, and cellulose solvent and organic solvent lignocellulose fractionation, COSLIF) for corn stover. At a high cellulase loading [15 filter paper units (FPUs) or 12.3 mg cellulase per gram of glucan], glucan digestibilities of the corn stover pretreated by DA and COSLIF were 84% at hour 72 and 97% at hour 24, respectively. At a low cellulase loading (5 FPUs per gram of glucan), digestibility remained as high as 93% at hour 24 for the COSLIF-pretreated corn stover but reached only approximately 60% for the DA-pretreated biomass. Quantitative determinations of total substrate accessibility to cellulase (TSAC), cellulose accessibility to cellulase (CAC), and non-cellulose accessibility to cellulase (NCAC) based on adsorption of a non-hydrolytic recombinant protein TGC were measured for the first time. The COSLIF-pretreated corn stover had a CAC of 11.57 m(2)/g, nearly twice that of the DA-pretreated biomass (5.89 m(2)/g). These results, along with scanning electron microscopy images showing dramatic structural differences between the DA- and COSLIF-pretreated samples, suggest that COSLIF treatment disrupts microfibrillar structures within biomass while DA treatment mainly removes hemicellulose. Under the tested conditions COSLIF treatment breaks down lignocellulose structure more extensively than DA treatment, producing a more enzymatically reactive material with a higher CAC accompanied by faster hydrolysis rates and higher enzymatic digestibility.

  2. Diverse Functional Roles of Monosaccharide Transporters and their Homologs in Vascular Plants: A Physiological Perspective

    Institute of Scientific and Technical Information of China (English)

    Thomas L. Slewinski

    2011-01-01

    Vascular plants contain two gene families that encode monosaccharide transporter proteins. The classical monosaccharide transporter(-like)gene superfamily is large and functionally diverse, while the recently identified SWEET transporter family is smaller and, thus far, only found to transport glucose. These transporters play essential roles at many levels, ranging from organelles to the whole plant. Many family members are essential for cellular homeostasis and re-productive success. Although most transporters do not directly participate in long-distance transport, their indirect roles greatly impact carbon allocation and transport flux to the heterotrophic tissues of the plant. Functional characterization of some members from both gene families has revealed their diverse roles in carbohydrate partitioning, phloem function,resource allocation, plant defense, and sugar signaling. This review highlights the broad impacts and implications of monosaccharide transport by describing some of the functional roles of the monosaccharide transporter(-like)superfamily and the SWEET transporter family.

  3. Modeling of percolation process in hemicellulose hydrolysis.

    Science.gov (United States)

    Cahela, D R; Lee, Y Y; Chambers, R P

    1983-01-01

    A mathematical model was developed for a percolation reactor in connection with consecutive first-order reactions. The model was designed to simulated acid-catalyzed cellulose or hemicellulose hydrolysis. The modeling process resulted in an analytically derived reactor equation, including mass-transfer effects, which was found to be useful in process desing and reactor optimization. The modedl was verified by experimental data obtained from hemicellulose hydrolysis.

  4. A sensitive and efficient method for determination of N-acetylhexosamines and N-acetylneuraminic acid in breast milk and milk-based products by high-performance liquid chromatography via UV detection and mass spectrometry identification.

    Science.gov (United States)

    Chuanxiang, Wu; Lian, Xia; Lijie, Liu; Fengli, Qu; Zhiwei, Sun; Xianen, Zhao; Jinmao, You

    2016-02-01

    A sensitive and efficient method of high performance liquid chromatography using 1-(2-naphthyl)-3-methyl-5-pyrazolone (NMP) as pre-column derivatization reagent coupled with UV detection (HPLC-UV) and online mass spectrometry identification was established for determination of the most common N-Acetylhexosamines (N-acetyl-d-glucosamine (GlcNAc) and N-acetyl-d-galactosamine (GalNAc)) and N-acetylneuraminic acid (Neu5Ac). In order to obtain the highest liberation level of the three monosaccharides without destruction of Neu5Ac or conversion of GlcNAc/GalNAc to GlcN/GalN in the hydrolysis procedure, the pivotal parameters affecting the liberation of N-acetylhexosamines/Neu5Ac from sample were investigated with response surface methodology (RSM). Under the optimized condition, maximum yield was obtained. The effects of key parameters on derivatization, separation and detection were also investigated. At optimized conditions, three monosaccharides were labeled fast and entirely, and all derivatives exhibited a good baseline resolution and high detection sensitivity. The developed method was linear over the calibration range 0.25-12μM, with R(2)>0.9991. The detection limits of the method were between 0.48 and 2.01pmol. Intra- and inter-day precisions for the three monosaccharides (GlcNAc, GalNAc and Neu5Ac) were found to be in the range of 3.07-4.02% and 3.69-4.67%, respectively. Individual monosaccharide recovery from spiked milk was in the range of 81%-97%. The sensitivity of the method, the facility of the derivatization procedure and the reliability of the hydrolysis conditions suggest the proposed method has a high potential for utilization in routine trace N-acetylhexosamines and Neu5Ac analysis in biological samples.

  5. In-gel microwave-assisted acid hydrolysis of proteins combined with liquid chromatography tandem mass spectrometry for mapping protein sequences.

    Science.gov (United States)

    Sun, Difei; Wang, Nan; Li, Liang

    2014-01-07

    We report an enabling method for mapping the protein sequence with high sequence coverage. This method combines the high separation power of gel electrophoresis for protein separation with the high sequence coverage capability of microwave-assisted acid hydrolysis (MAAH) mass spectrometry (MS). In-gel MAAH using 25% trifluoroacetic acid was developed and optimized for degrading the gel-separated protein into small peptides suitable for tandem MS sequencing. For bovine serum albumin (BSA) (∼67 kDa), with 4 μg of protein loading onto a gel for separation, followed by excising the protein gel band for in-gel MAAH and then injecting ∼2 μg of the resultant peptides into a liquid chromatography quadrupole time-of-flight mass spectrometer for analysis, 689 ± 54 (n = 3) unique peptides were identified with a protein sequence coverage of 99 ± 1%. Both the number of peptides detected and sequence coverage decreased as the sample amount decreased, mainly due to background interference: 316 ± 59 peptides and 94 ± 3% coverage for 2 μg loading, 136 ± 19 and 76 ± 5% for 1 μg loading, and 30 ± 2 and 32 ± 2% for 0.5 μg loading. To demonstrate the general applicability of the method, 10 gel bands from gel electrophoresis of an albumin-depleted human plasma sample were excised for in-gel MAAH LC-MS analysis. In total, 19 relatively high abundance proteins with molecular weights ranging from ∼8 to ∼160 kD could be mapped with coverage of 100% for six proteins (MW 8759 to 68 425 Da), 96-98% for five proteins (MW 11 458 to 36 431 Da), 92% for three proteins (MW 15 971 to 36 431 Da), 80-87% for four proteins (MW 42 287 to 162 134 Da), and 56% for one protein (MW 51 358 Da). Finally, to demonstrate the applicability of the method for more detailed analysis of complex protein mixtures, two-dimensional (2D) gel electrophoresis was combined with in-gel MAAH, affinity purification, and LC-MS/MS to characterize six bovine alpha-S1-casein phosphoprotein

  6. 基于3,5-二硝基水杨酸法的水稻秸秆酶解工艺%Enzymatic Hydrolysis of Rice Straw Based on 3,5-dinitrosalicylic Acid Method

    Institute of Scientific and Technical Information of China (English)

    李彬; 高翔; 孙倩; 陈坤杰

    2013-01-01

    For the purpose to improve the conversion rate of reducing sugar of rice straw, the cellulose was used in the enzymatic hydrolysis of rice straw. The content of reducing sugar was detected by 3,5-dinitrosalicylic acid method. The enzyme concentration, hydrolysis time and temperature were selected as inspecting factors. Meantime, comparisons of the enzymatic hydrolysis of rural rice straw with that of steam explosion pretreatment rice straw were made. The results showed when the cellulose weight content taking 10% of the dry rice straw, enzymatic hydrolysis time of 48 h and reaction temperature of 50℃ were ideal reaction conditions. The maximum reducing sugar yield of enzymatic hydrolysis original rice straw was 9.7% . The highest reducing sugar yield of enzymatic hydrolysis steam explosion rice straw was approximately 34. 3 %. Steam explosion pretreatment can obviously improve the production of reducing sugar of enzymatic hydrolysis rice straw, and at the same time accelerate the reaction rate.%为了提高汽爆水稻秸秆还原糖的转化率,采用纤维素酶对水稻秸秆进行酶解实验.还原糖的含量用3,5-二硝基水杨酸法进行测定.实验选用加酶量、酶解时长和反应温度作为考察因素,以原始水稻秸秆与蒸汽爆破预处理水稻秸秆作对比.结果表明纤维素酶用量占秸秆干物质质量的10%,酶解时长48 h,反应温度50℃是一个较为理想的反应条件;原始水稻秸秆最大酶解还原糖产量约为9.7%;蒸汽爆破水稻秸秆最大酶解还原糖产量约为34.3%;蒸汽爆破预处理能够显著提高水稻秸秆的酶解还原糖产量,并缩短酶解反应时间.

  7. SYNTHESIS,HELICITY,AND BIOLOGICAL PROPERTIES OF MONOSACCHARIDE-CONTAINING POLY(PHENYLACETYLENE)S

    Institute of Scientific and Technical Information of China (English)

    Jacky W.Y.Lam; Kevin K.L.Cheuk; Bing-shi Li; Yong Xie; Ben-zhong Tang

    2007-01-01

    Poly(phenylacetylene)s bearing monosaccharide pendant groups are synthesized in high yields by [Rh(nbd)Cl]2 catalyst.The polymers have high molecular weights and give satisfactory spectroscopic data corresponding to their molecular structures.They are thermally quite stable(≥300℃)and show strong circular dichroism signals in the visible spectral region owing to the helicity of the polyene backbone.The monosaccharide-containing polyacetylenes are cytophilic and can stimulate the growth of living cells.

  8. Study on Molecular Recognition of Crown Ethers to Aniline and Monosaccharides

    Institute of Scientific and Technical Information of China (English)

    QI Li-Ya; TENG Qi-Wen; WU Shi; LIU Zheng-Zheng

    2005-01-01

    Theoretical study on coordinates between crown ethers and aniline as well as monosaccharides is performed by AM1, MNDO and PM3 methods.It is indicated that crown ethers possess ability to recognize polar guests especially ionic guests and monosaccharides.Electronic spectra of coordinates are computed by the INDO/SCI method.The reason of the blue-shift for UV absorption of complexes relative to that of hosts is discussed and electronic transition is theoretic- cally assigned.

  9. Acylglucuronide in alkaline conditions: migration vs. hydrolysis.

    Science.gov (United States)

    Di Meo, Florent; Steel, Michele; Nicolas, Picard; Marquet, Pierre; Duroux, Jean-Luc; Trouillas, Patrick

    2013-06-01

    This work rationalizes the glucuronidation process (one of the reactions of the phase II metabolism) for drugs having a carboxylic acid moiety. At this stage, acylglucuronides (AG) metabolites are produced, that have largely been reported in the literature for various drugs (e.g., mycophenolic acid (MPA), diclofenac, ibuprofen, phenylacetic acids). The competition between migration and hydrolysis is rationalized by adequate quantum calculations, combing MP2 and density functional theory (DFT) methods. At the molecular scale, the former process is a real rotation of the drug around the glucuconic acid. This chemical-engine provides four different metabolites with various toxicities. Migration definitely appears feasible under alkaline conditions, making proton release from the OH groups. The latter reaction (hydrolysis) releases the free drug, so the competition is of crucial importance to tackle drug action and elimination. From the theoretical data, both migration and hydrolysis appear kinetically and thermodynamically favored, respectively.

  10. Neutral monosaccharides from a hypersaline tropical environment: Applications to the characterization of modern and ancient ecosystems

    Science.gov (United States)

    Moers, M. E. C.; Larter, S. R.

    1993-07-01

    Surficial and buried sediment samples from a hypersaline lagoon-sabkha system (Abu Dhabi, United Arab Emirates) were analysed for carbohydrates (as neutral monosaccharides) to distinguish and characterise various types of recent and ancient tropical ecosystems on a molecular level. The samples consisted of surficial and buried microbial mats, lagoonal sediments containing seagrass ( Halodule uninervis), and mangrove ( Avicennia marina) paleosoils and handpicked mangrove leaves, ranging in age from contemporary to ca. 6000 yr Bp. Analysis of quantitative neutral monosaccharide data by multivariate techniques shows that various groups can be distinguished: intact vascular plant material (mangrove leaf) contains high amounts of arabinose and glucose and hardly any partially methylated monosaccharides, whereas microbial mats in general and lagoonal seagrass sediments show high contributions of fucose, ribose, mannose, galactose and partially methylated monosaccharides. Moreover, surficial microbial mats consisting of filamentous cyanobacteria ( Microcoleus chtonoplastes, Lyngbya aestuarii) can be distinguished from other mats and sediments containing coccoid cyanobacteria ( Entophysalis major) and/or fermenting, sulphate reducing, and methanogenic bacteria on the basis of high contributions of specific groups of partially methylated monosaccharides and other "minor" saccharides. The neutral monosaccharides present in mangrove paleosoils are for a substantial part derived from microorganisms.

  11. SUT Sucrose and MST Monosaccharide Transporter Inventory of the Selaginella Genome.

    Science.gov (United States)

    Lalonde, Sylvie; Frommer, Wolf B

    2012-01-01

    Most metazoa use hexose transporters to acquire hexoses from their diet and as a transport form for distributing carbon and energy within their bodies; insects use trehalose, and plants use sucrose as their major form for translocation. Plant genomes contain at least three families of mono- and disaccharide transporters: monosaccharide/polyol transporters that are evolutionary closely related to the yeast and human glucose transporters, sucrose transporters of the SUT family, which similar to the hexose transporters belong to the major facilitator superfamily, but share only minimal amino acid sequence homology with the hexose transporters, and the family of SWEET sugar transporters conserved between animals and plants. Recently, the genome sequence of the spikemoss Selaginella has been determined. In order to study the evolution of sugar transport in plants, we carefully annotated of the complement of sugar transporters in Selaginella. We review the current knowledge regarding sugar transport in spikemoss and provide phylogenetic analyses of the complement of MST and SUT homologs in Selaginella (and Physcomitrella).

  12. SUT sucrose and MST monosaccharide transporter inventory of the Selaginella genome

    Directory of Open Access Journals (Sweden)

    Sylvie eLalonde

    2012-02-01

    Full Text Available While most metazoa mainly use hexose transporters to acquire hexoses from their diet and as a transport form for distributing carbon and energy within their bodies, insects use trehalose and plants use sucrose as their major form for translocation. Plant genomes contain at least three families of mono- and disaccharide transporters: monosaccharide/polyol transporters that are evolutionary closely related to the yeast and human glucose transporters, sucrose transporters of the SUT family, which similar to the hexose transporters belong to the major facilitator superfamily (MFS, but share only minimal amino acid sequence homology to the hexose transporters, and the family of SWEET sugar transporters conserved between animals and plants. Recently, the genome sequence of the spikemoss Selaginella has been determined. In order to study the evolution of sugar transport in plants, we carried out a careful annotation of the complement of sugar transporters in Selaginella. We review what is known about sugar transport in spikemoss and provide phylogenetic analyses of the complement of MST and SUT homologs in Selaginella.

  13. Lactic acid and thermal treatments trigger the hydrolysis of myo-inositol hexakisphosphate and modify the abundance of lower myo-inositol phosphates in barley (Hordeum vulgare L..

    Directory of Open Access Journals (Sweden)

    Barbara U Metzler-Zebeli

    Full Text Available Barley is an important source of dietary minerals, but it also contains myo-inositol hexakisphosphate (InsP6 that lowers their absorption. This study evaluated the effects of increasing concentrations (0.5, 1, and 5%, vol/vol of lactic acid (LA, without or with an additional thermal treatment at 55°C (LA-H, on InsP6 hydrolysis, formation of lower phosphorylated myo-inositol phosphates, and changes in chemical composition of barley grain. Increasing LA concentrations and thermal treatment linearly reduced (P<0.001 InsP6-phosphate (InsP6-P by 0.5 to 1 g compared to the native barley. In particular, treating barley with 5% LA-H was the most efficient treatment to reduce the concentrations of InsP6-P, and stimulate the formation of lower phosphorylated myo-inositol phosphates such as myo-inositol tetraphosphate (InsP4 and myo-inositol pentaphosphates (InsP5. Also, LA and thermal treatment changed the abundance of InsP4 and InsP5 isomers with Ins(1,2,5,6P4 and Ins(1,2,3,4,5P5 as the dominating isomers with 5% LA, 1% LA-H and 5% LA-H treatment of barley, resembling to profiles found when microbial 6-phytase is applied. Treating barley with LA at room temperature (22°C increased the concentration of resistant starch and dietary fiber but lowered those of total starch and crude ash. Interestingly, total phosphorus (P was only reduced (P<0.05 in barley treated with LA-H but not after processing of barley with LA at room temperature. In conclusion, LA and LA-H treatment may be effective processing techniques to reduce InsP6 in cereals used in animal feeding with the highest degradation of InsP6 at 5% LA-H. Further in vivo studies are warranted to determine the actual intestinal P availability and to assess the impact of changes in nutrient composition of LA treated barley on animal performance.

  14. Selective cleavage and anticoagulant activity of a sulfated fucan: stereospecific removal of a 2-sulfate ester from the polysaccharide by mild acid hydrolysis, preparation of oligosaccharides, and heparin cofactor II-dependent anticoagulant activity.

    Science.gov (United States)

    Pomin, Vitor H; Pereira, Mariana S; Valente, Ana-Paula; Tollefsen, Douglas M; Pavão, Mauro S G; Mourão, Paulo A S

    2005-04-01

    A linear sulfated fucan with a regular repeating sequence of [3)-alpha-L-Fucp-(2SO4)-(1-->3)-alpha-L-Fucp-(4SO4)-(1-->3)-alpha-L-Fucp-(2,4SO4)-(1-->3)-alpha-L-Fucp-(2SO4)-(1-->]n is an anticoagulant polysaccharide mainly due to thrombin inhibition mediated by heparin cofactor II. No specific enzymatic or chemical method is available for the preparation of tailored oligosaccharides from sulfated fucans. We employ an apparently nonspecific approach to cleave this polysaccharide based on mild hydrolysis with acid. Surprisingly, the linear sulfated fucan was cleaved by mild acid hydrolysis on an ordered sequence. Initially a 2-sulfate ester of the first fucose unit is selectively removed. Thereafter the glycosidic linkage between the nonsulfated fucose residue and the subsequent 4-sulfated residue is preferentially cleaved by acid hydrolysis, forming oligosaccharides with well-defined size. The low-molecular-weight derivatives obtained from the sulfated fucan were employed to determine the requirement for interaction of this polysaccharide with heparin cofactor II and to achieve complete thrombin inhibition. The linear sulfated fucan requires significantly longer chains than mammalian glycosaminoglycans to achieve anticoagulant activity. A slight decrease in the molecular size of the sulfated fucan dramatically reduces its effect on thrombin inactivation mediated by heparin cofactor II. Sulfated fucan with approximately 45 tetrasaccharide repeating units binds to heparin cofactor II but is unable to link efficiently the plasma inhibitor and thrombin. This last effect requires chains with approximately 100 or more tetrasaccharide repeating units. We speculate that the template mechanism may predominate over the allosteric effect in the case of the linear sulfated fucan inactivation of thrombin in the presence of heparin cofactor II.

  15. HYDROLYSIS OF PAPER-DISHWARE WASTES BY CELLULASE

    Institute of Scientific and Technical Information of China (English)

    Jie Lu; Shulan Shi; Runan Yang; Fuzheng Liang

    2004-01-01

    The optimum conditions of hydrolysis of cellulosic wastes by cellulase were studied. The results show that the optimum conditions of sulfuric acid pretreatment were sulfuric acid consistency 0.3M,pretreatment temperature 100℃, pretreatment time 4hours. After sulfuric acid pretreatment, the optimum conditions of hydrolysis by cellulase were enzymatic temperature 50℃ ,enzymatic time 48hours,pH4.8,the charge of cellulase 100IU/g and the substraste consistency 60g/l. Meanwhile this paper studies that the structural change of cellulose during sulfuric acid pretreatment and cellulase hydrolysis by analyzing the infrared spectra.

  16. Effect of ionic liquid pretreatment step on acid hydrolysis of two high crystallization polysaccharide%离子液体[Bmim]Cl预处理对两种高结晶多糖酸水解的影响

    Institute of Scientific and Technical Information of China (English)

    李娜; 王兆梅; 肖凯军

    2012-01-01

    以酵母β-葡聚糖和凝结多糖这两种高结晶多糖为研究对象,采用偏光显微镜、X射线衍射(XRD)和DNS法研究了离子液体[Bmim]Cl预处理对多糖结晶结构和酸水解效率的影响。XRD图谱分析发现,[Bmim]Cl预处理后酵母β-葡聚糖和凝结多糖的结晶度明显下降。离子液体[Bmim]Cl预处理酵母β-葡聚糖和凝结多糖显著提高其酸水解效率。在4mol/LTFA及100℃条件下,酵母β-葡聚糖(水解时间2h)和凝结多糖(水解时间3h)酸水解产物中还原糖的含量分别为84.36g/100g和96.07g/100g,明显高于未经离子液体处理的53.44g/100g和46.80g/100g。%The effect of an ionic liquid 1-butyl-3-methylimidazoliumchloride([Bmim]Cl)pretreatment on the efficiency of the acid hydrolysis and crystallinity of brewer yeast-β-glucans and curdlan was investigated by using polarized optical microscope,X-ray diffraction(XRD)and 3,5-dinitrosalicylic acid(DNS)method.It was demonstrated from the XRD spectrometry that the crystallinity of brewer yeast-β-glucans and curdlan declined dramatically with ionic liquid pretreated.Brewer yeast-β-glucans and curdlan pretreated with[Bmim]Cl enhanced the efficiency and increased the reducing sugar content during the acid hydrolysis.The reducing sugar content of brewer yeast-β-glucans(acid hydrolysis for 2h)and curdlan(acid hydrolysis for 3h)with the ionic liquid pretreated were 84.36g/100g and 96.07g/100g respectively,much higher than that of the untreated samples which were 53.44g/100g and 46.80g/100g in 4mol/L TFA at 100℃.

  17. Selective production of ricinoleic acid by hydrolysis of castor oil using lipase immobilized in N-polyisopropylacrylamide gel; Ripaze koteika N-poriisopuropiruakuriruamidogeru wo mochiita himashiyu no kasuibunaki ni yoru rishinorusan no sentakuteki seisei

    Energy Technology Data Exchange (ETDEWEB)

    Goto, M.; Hatanaka, C.; Haraguchi, T. [Kitakyushu National College of Technology, Fukuoka (Japan)

    2000-05-10

    Lipase from Candida cylindracea or Rhizopus was immobilized in gel beads prepared by copolymerization of N-isopropylacrylamide, N-N'-methylenebisacrylamide, and acrylamide. The hydrolysis reaction of castor oil was carried out at 37 degree C by using immobilized lipase or free lipase. The optimal condition of immobilization of lipase and the productivity of ricinoleic acid is investigated. It is found that thermal inactivation of enzyme was suppressed and the formation of by-products such as estolide decreases by immobilization into the gel compared with free lipase. (author)

  18. THE ANTIOXIDANT ACTIVITY OF THE PRODUCTS OF HYDROLYSIS OF NATURAL POLYMERS (MANNAN AND FUCOIDAN

    Directory of Open Access Journals (Sweden)

    D. A. Cherenkov

    2012-01-01

    Full Text Available The antioxidant activity of oligosaccharides, obtained from mild acid and fermentative mannan and fucoidan hydrolysis was investigated. Dependence of manno- and fucoooligosaccharides antioxidant activity on hydrolysis conditions was shown.

  19. Hydrolysis of soy isoflavone conjugates using enzyme may underestimate isoflavone concentrations in tissue

    Institute of Scientific and Technical Information of China (English)

    Hebron C. Chang; Myriam Laly; Melody Harrison; Thomas M. Badger

    2005-01-01

    Objective: To investigate the differences of using enzymatic hydrolysis and acid hydrolysis for identification and quantification of isoflavone aglycones from biomatrices. Methods: β-glucuronidase/sulfatase isolated from Helix pomatia for routine enzymatic hydrolysis or 6N HCl was used to release glucuronide and sulfate conjugates in the serum, urine and tissue samples. Profiles of soy isoflavones after enzymatic hydrolysis or acid hydrolysis in several tissues of rat fed with diets containing soy protein isolate were also compared using LC/MS and HPLC-ECD. Results: Acid hydrolysis released more aglycone than enzymatic digestion ( P <0.05) in liver tissue. The total genistein, daidzein and other metabolites were 20% to 60% lower in samples from enzymatic hydrolysis than in acid hydrolysis. Conclusion: These results indicated that unknown factors in tissues reduced the enzymatic hydrolytic efficiency for releasing isoflavone aglycones even in optimized condition. This would underestimate isoflavone tissue concentrations up to 60%.

  20. Weak-acid sites catalyze the hydrolysis of crystalline cellulose to glucose in water: importance of post-synthetic functionalization of the carbon surface.

    Science.gov (United States)

    To, Anh The; Chung, Po-Wen; Katz, Alexander

    2015-09-14

    The direct hydrolysis of crystalline cellulose to glucose in water without prior pretreatment enables the transformation of biomass into fuels and chemicals. To understand which features of a solid catalyst are most important for this transformation, the nanoporous carbon material MSC-30 was post-synthetically functionalized by oxidation. The most active catalyst depolymerized crystalline cellulose without prior pretreatment in water, providing glucose in an unprecedented 70 % yield. In comparison, virtually no reaction was observed with MSC-30, even when the reaction was conducted in aqueous solution at pH 2. As no direct correlations between the activity of this solid-solid reaction and internal-site characteristics, such as the β-glu adsorption capacity and the rate of catalytic hydrolysis of adsorbed β-glu strands, were observed, contacts of the external surface with the cellulose crystal are thought to be key for the overall efficiency.

  1. Selective Acid Hydrolysis Condition for the Composition and Linkage with a Fructofuranosyl Backbone of a Polysaccharide from Angelica sinensis (Oliv) Diels

    Institute of Scientific and Technical Information of China (English)

    Gui Yun XU; Yang CHEN; Ru Xian CHEN

    2006-01-01

    A new polysaccharide was extracted and purified from the roots of Angelica sinensis (Oliv) Diels (ASD). Its composition and linkage was elucidated by selective hydrolysis and GC/MS analysis of its derivatives. The polysaccharide was made of→1) Fruf(2→and→6) GlCp (1→as its backbone with highly branched structure. To our best knowledge, this is the first report of the fructose residue in polysaccharides from the roots of the ASD.

  2. Fundamental study of the mechanism and kinetics of cellulose hydrolysis by acids and enzymes. Final report, June 1, 1978-January 31, 1981

    Energy Technology Data Exchange (ETDEWEB)

    Gong, C.S.; Chang, M.

    1981-02-01

    There are three basic enzymes (e.g., endoglucanase (C/sub x/), exoglucanase (C/sub 1/) and cellobiase) comprising the majority of extracellular cellulase enzymes produced by the cellulolytic mycelial fungi, Trichoderma reesei, and other cellulolytic microorganisms. The enzymes exhibited different mode of actions in respect to the hydrolysis of cellulose and cellulose derived oligosaccharides. In combination, these enzymes complimented each other to hydrolyze cellulose to its basic constituent, glucose. The kinetics of cellobiase were developed on the basis of applying the pseudo-steady state assumption to hydrolyze cellobiose to glucose. The results indicated that cellobiase was subjected to end-product inhibition by glucose. The kinetic modeling of exoglucanase (C/sub 1/) with respect to cellodextrins was studied. Both glucose and cellobiose were found to be inhibitors of this enzyme with cellobiose being a stronger inhibitor than glucose. Similarly, endoglucanase (C/sub x/) is subject to end-product inhibition by glucose. Crystallinity of the cellulose affects the rate of hydrolysis by cellulases. Hence, the changes in crystallinity of cellulose in relation to chemical pretreatment and enzyme hydrolysis was compared. The study of cellulase biosynthesis resulted in the conclusion that exo- and endo-glucanases are co-induced while cellobiase is synthesized independent of the other two enzymes. The multiplicity of cellulase enzymes are the end results of post-translational modification during and/or after the secretion of enzymes into growth environment.

  3. Effects of pH on the hydrolysis of lignocellulosic wastes and volatile fatty acids accumulation: the contribution of biotic and abiotic factors.

    Science.gov (United States)

    Chen, Yi; Wen, Yue; Zhou, Junwei; Xu, Chao; Zhou, Qi

    2012-04-01

    In this study, a combination of micro-scale structure and extracellular enzyme activity (EEA) analysis was successfully used to explore the effect of pH (from 6.0 to 12.0) on wetland plant litter (WPL) hydrolysis and VFAs accumulation. During 30days of fermentation, the maximum VFAs production and abiotic release of carbohydrate, combined with the minimum EEAs were observed at pH 12.0, suggesting that abiotic factors were most important for hydrolysis and VFAs accumulation at pH 12.0. As the pH decreased, the factors most important to carbohydrate hydrolysis shifted from abiotic factors to biotic factors with the maximum bio-release of carbohydrate occurring at pH 9.0. Further investigation showed that pH 9.0 could significantly enhance the bio-release of carbohydrate through the increase in the mesoporous surface area, surface cellulose accessibility and cellulase activity. Alkaline fermentation at ambient temperature can be considered as a sustainable technology for VFAs recovery and WPL management.

  4. Synthesis of a series of monosaccharide-fipronil conjugates and their phloem mobility.

    Science.gov (United States)

    Yuan, Jian-Guo; Wu, Han-Xiang; Lu, Meng-Ling; Song, Gao-Peng; Xu, Han-Hong

    2013-05-08

    To test the effect of adding different monosaccharide groups to a non-phloem-mobile insecticide on the phloem mobility of the insecticide, a series of conjugates of different monosaccharides and fipronil were synthesized using the trichloroacetimidate method. Phloem mobility tests in castor bean ( Ricinus communis L.) seedlings indicated that the phloem mobility of these conjugates varied markedly. L-Rhamnose-fipronil and D-fucose-fipronil displayed the highest phloem mobility among all of the tested conjugates. Conjugating hexose, pentose, or deoxysugar to fipronil through an O-glycosidic linkage can confer phloem mobility to fipronil in R. communis L. effectively, while the -OH orientation of the monosaccharide substantially affected the phloem mobility of the conjugates.

  5. Theoretical studies of binding of mannose-binding protein to monosaccharides

    Science.gov (United States)

    Aida-Hyugaji, Sachiko; Takano, Keiko; Takada, Toshikazu; Hosoya, Haruo; Kojima, Naoya; Mizuochi, Tsuguo; Inoue, Yasushi

    2004-11-01

    Binding properties of mannose-binding protein (MBP) to monosaccharides are discussed based on ab initio molecular orbital calculations for cluster models constructed. The calculated binding energies indicate that MBP has an affinity for N-acetyl- D-glucosamine, D-mannose, L-fucose, and D-glucose rather than D-galactose and N-acetyl- D-galactosamine, which is consistent with the biochemical experimental results. Electrostatic potential surfaces at the binding site of four monosaccharides having binding properties matched well with that of MBP. A vacant frontier orbital was found to be localized around the binding site of MBP, suggesting that MBP-monosaccharide interaction may occur through electrostatic and orbital interactions.

  6. Occurrence and human exposure of p-hydroxybenzoic acid esters (parabens), bisphenol A diglycidyl ether (BADGE), and their hydrolysis products in indoor dust from the United States and three East Asian countries.

    Science.gov (United States)

    Wang, Lei; Liao, Chunyang; Liu, Fang; Wu, Qian; Guo, Ying; Moon, Hyo-Bang; Nakata, Haruhiko; Kannan, Kurunthachalam

    2012-11-06

    p-Hydroxybenzoic acid esters (parabens) and bisphenol A diglycidyl ether (BADGE) are widely present in personal care products, food packages, and material coatings. Nevertheless, little is known about the occurrence of these compounds in indoor dust. In this study, we collected 158 indoor dust samples from the U.S., China, Korea, and Japan and determined the concentrations of 11 target chemicals, viz., six parabens and their common hydrolysis product, 4-hydroxybenzoic acid (4-HB), as well as BADGE and its three hydrolysis products (BADGE·H(2)O, BADGE·2H(2)O, and BADGE·HCl·H(2)O). All of the target compounds were found in dust samples from four countries. Concentrations of sum of six parabens in dust were on the order of several hundred to several thousands of nanogram per gram. Geometric mean concentrations of BADGEs in dust ranged from 1300 to 2890 ng/g among four countries. Methyl paraben (MeP), propyl paraben (PrP), BADGE·2H(2)O, and BADGE·HCl·H(2)O were the predominant compounds found in dust samples. This is the first report of BADGE and its hydrolysis products (BADGEs) in indoor dust samples and of parabens in indoor dust from Asian countries. On the basis of the measured concentrations of target chemicals, we estimated the daily intake (EDI) via dust ingestion. The EDIs of parabens via dust ingestion were 5-10 times higher in children than in adults. Among the four countries studied, the EDIs of parabens (5.4 ng/kg-bw/day) and BADGEs (6.5 ng/kg-bw/day) through dust ingestion were the highest for children in Korea and Japan.

  7. Separation of monosaccharides by solid-phase extraction with ionic liquid-modified microporous polymers.

    Science.gov (United States)

    Tian, Minglei; Bi, Wentao; Row, Kyung H

    2011-11-01

    Ionic liquid-modified porous polymers with large surface area and large amount of functional groups were developed and used in SPE to separate four monosaccharides. Adsorption isotherm showed that the sorbent with amino ionic liquid groups had the highest interaction with the target compounds. The mobile phase of acetonitrile/water 85:15 and 73:30 v/v can successfully separate the monosaccharides. The sorbent produced reproducible results and performed stably, demonstrating its potential applicability in the separation of extract from natural plant. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A new type of endo-xyloglucan transferase devoted to xyloglucan hydrolysis in the cell wall of azuki bean epicotyls.

    Science.gov (United States)

    Tabuchi, A; Mori, H; Kamisaka, S; Hoson, T

    2001-02-01

    A new type of xyloglucan-degrading enzyme was isolated from the cell wall of azuki bean (Vigna angularis Ohwi et Ohashi cv. Takara) epicotyls and its characteristics were determined. The enzyme was purified to apparent homogeneity by Concanavalin A (Con A)-Sepharose, cation exchange, and gel filtration columns from a cell wall protein fraction extracted with 1 M sodium chloride. The purified enzyme gave a single protein band of 33 kDa on SDS-PAGE. The enzyme specifically cleaved xyloglucans and showed maximum activity at pH 5.0 when assayed by the iodine-staining method. An increase in reducing power in xyloglucan solution was clearly detected after treatment with the purified enzyme. Xyloglucans with molecular masses of 500 and 25 kDa were gradually hydrolyzed to 5 kDa for 96 h without production of any oligo- or monosaccharide with the purified enzyme. The purified enzyme did not show an endo-type transglycosylation reaction, even in the presence of xyloglucan oligosaccharides. Partial amino acid sequences of the enzyme shared an identity with endo-xyloglucan transferase (EXGT) family, especially with xyloglucan endotransglycosylase (XET) from nasturtium. These results suggest that the enzyme is a new member of EXGT devoted solely to xyloglucan hydrolysis.

  9. Subcritical water hydrolysis of rice straw for reducing sugar production with focus on degradation by-products and kinetic analysis.

    Science.gov (United States)

    Lin, Richen; Cheng, Jun; Ding, Lingkan; Song, Wenlu; Qi, Feng; Zhou, Junhu; Cen, Kefa

    2015-06-01

    The competitive reactions of reducing sugar production and degradation in the subcritical water hydrolysis of rice straw were investigated to optimise reducing sugar yield. The optimised conditions (280°C, 20 MPa, rice straw concentration of 5 wt.% and agitation speed of 200 rpm) resulted in a reducing sugar yield of 0.346 g/g rice straw because of the enhanced reducing sugar production and decreased sugar degradation. The sugar yield increased when the temperature increased from 250°C to 280°C, but it decreased when the temperature further increased to 300°C because of the degradation of monosaccharides (e.g. glucose and xylose) into by-products (e.g. 2-methyltetrahydrofuran and acetic acid). A first-order reaction model was developed to elucidate the competitive reaction kinetics of sugar production and degradation at various temperatures. The highest reducing sugar yield based on the model was achieved at 280°C with the highest production and lowest degradation rates.

  10. Engineered yeast whole-cell biocatalyst for direct degradation of alginate from macroalgae and production of non-commercialized useful monosaccharide from alginate.

    Science.gov (United States)

    Takagi, Toshiyuki; Yokoi, Takahiro; Shibata, Toshiyuki; Morisaka, Hironobu; Kuroda, Kouichi; Ueda, Mitsuyoshi

    2016-02-01

    Alginate is a major component of brown macroalgae. In macroalgae, an endolytic alginate lyase first degrades alginate into oligosaccharides. These oligosaccharides are further broken down into monosaccharides by an exolytic alginate lyase. In this study, genes encoding various alginate lyases derived from alginate-assimilating marine bacterium Saccharophagus degradans were isolated, and their enzymes were displayed using the yeast cell surface display system. Alg7A-, Alg7D-, and Alg18J-displaying yeasts showed endolytic alginate lyase activity. On the other hand, Alg7K-displaying yeast showed exolytic alginate lyase activity. Alg7A, Alg7D, Alg7K, and Alg18J, when displayed on yeast cell surface, demonstrated both polyguluronate lyase and polymannuronate lyase activities. Additionally, polyguluronic acid could be much easily degraded by Alg7A, Alg7K, and Alg7D than polymannuronic acid. In contrast, polymannuronic acid could be much easily degraded by Alg18J than polyguluronic acid. We further constructed yeasts co-displaying endolytic and exolytic alginate lyases. Degradation efficiency by the co-displaying yeasts were significantly higher than single alginate lyase-displaying yeasts. Alg7A/Alg7K co-displaying yeast had maximum alginate degrading activity, with production of 1.98 g/L of reducing sugars in a 60-min reaction. This system developed, along with our findings, will contribute to the efficient utilization and production of useful and non-commercialized monosaccharides from alginate by Saccharomyces cerevisiae.

  11. Synthesis and hydrolysis resisting capacity of ethoxylated ricinoleic acid methyl esters%蓖麻油酸甲酯乙氧基化物的合成与耐酸耐碱性研究

    Institute of Scientific and Technical Information of China (English)

    张谦; 孙永强; 王万绪; 智丽飞; Martino Di Serio; 刘伟

    2015-01-01

    Ethoxylated ricinoleic acid methyl esters (ECAME - 10)obtained directly from castor oil acid methyl esters by the use of a special homogeneous catalyst. The average ethylene oxide (EO)adduct number of ECAME - 10 was determined by saponification value,gas chromatography (GC)and 1 HNMR. The hydrolysis resisting capacity of ECAME - 10 was investigated under different pH value conditions. The appearance changes of ECAME - 10 solution under different storing time periods was tracked and photographed and surface tension of different stages of the solution at different stages was measured. Results showed that the hydrolysis resisting capacity of ECAME - 10 is rather strong. The hydrolysis rate of ECAME - 10 is below 40% in pH value range of 4 - 9 after eight weeks. Surface tension of solutions can be kept stable after the hydrolysis reaction.%在一定的温度和压力条件下,以及特制的均相催化剂作用下,直接由蓖麻油酸甲酯得到了产物蓖麻油酸甲酯乙氧基化物(ECAME -10)。通过皂化值、气相色谱(GC)和1 HNMR 测定了ECAME -10的平均环氧乙烷(EO)加合数,在不同pH条件下测定了ECAME -10的耐酸耐碱性,并跟踪拍摄了不同pH溶液不同阶段的外观照片,同时测定了不同阶段溶液的表面张力。结果显示:ECAME -10有较强的抗水解能力,当pH =4~9时,ECAME -10的水解较慢,8周后其水解率在40%以下;水解后的表面张力数据表明,水解后溶液的表面张力可保持稳定。

  12. 酶解辅助乙醇浸提法提取青梅中的有机酸%Study on total organic acid extracting from sour plum by enzyme-assisted alcohol hydrolysis

    Institute of Scientific and Technical Information of China (English)

    鲁旺旺; 杜冰; 温升南; 陈金明; 白永亮; 黄守耀; 杨公明

    2011-01-01

    采用低温酶解辅助乙醇浸提法代替传统乙醇回流法提取青梅中的有机酸,用单因素试验和响应面分析法(Box-Bchnken)研究酶液添加量、酶解时间、酶解温度对乙醇提取青梅肉中有机酸效果的影响.以提取液中总有机酸提取率为响应值,通过响应面分析优化青梅有机酸提取工艺条件.结果表明:果胶酶对青梅酶解能力显著,影响青梅有机酸提取效果的主要因素为酶解温度、酶解时间、酶添加量.青梅中有机酸适宜酶解辅助浸提提取的工艺条件为酶添加量31.6 U/mL、酶解温度45.67℃、酶解时间3.41 h,相应提取液中总有机酸的提取率为35.49%.较传统乙醇回流法提取率(29.10%)有显著提高.%The technology was studied of total organic extracted from Sour Plum by enzymatic hydrolysis. Based on single factor test, the effects of the concentration of enzyme, temperature and time of enzymatic hydrolysis on the extraction yield of total organic acid from Sour Plum were studied by response surface methodology (RSM).The results indicated that pectinase showed the better ability of enzymatic hydrolysis. The optimum conditions of enzymatic hydrolysis were: 31.6 U/mL 45.67 ℃ and 3.41 h. The highest yield of total organic acid was 35.49%.

  13. Optimization Study on Processing Conditions of Corn Resistant Starch by Autoclaving and Acid Hydrolysis Treatment%压热酸解法制备玉米抗性淀粉的工艺优化

    Institute of Scientific and Technical Information of China (English)

    冯铄涵; 阚建全

    2011-01-01

    The resistant starch was prepared with the High amylose corn starch by autoclaving-cooling cycles combined with acids hydrolysis treatment.The effects of concentration of starch solution,autoclaved temperature,autoclaved time and times of autoclaved-cooling cycles on the content of RS were studied in the autoclaved treatment.The type,concentration and treatment time of acids were also studied in the acid hydrolysis process.The results showed that the optimum conditions is: 30% starch solution was autoclaved at 125℃ for 45min,after repeated 2 times,0.15mol/L citric acid hydrolysised for 12h.The yield of resistant starch is up to 39.27%.%以高直链玉米淀粉为原料,研究压热-冷却循环结合酸解法制备抗性淀粉的最佳工艺条件。通过单因素实验和正交实验探讨了压热-冷却循环过程中淀粉溶液浓度、压热温度、压热时间、循环次数以及酸解处理过程中酸的种类、酸的浓度、酸解时间对抗性淀粉得率的影响。结果表明,在淀粉溶液浓度为30%、压热温度125℃、压热时间45min条件下,经过2次压热-冷却循环,然后0.15mol/L柠檬酸水解处理12h,在此条件下抗性淀粉得率可达39.27%。

  14. Analysis of twenty phenolic compounds in human urine: hydrochloric acid hydrolysis, solid-phase extraction based on K2CO 3-treated silica, and gas chromatography tandem mass spectrometry.

    Science.gov (United States)

    Lu, Dasheng; Feng, Chao; Wang, Dongli; Lin, Yuanjie; Ip, Ho Sai Simon; She, Jianwen; Xu, Qian; Wu, Chunhua; Wang, Guoquan; Zhou, Zhijun

    2015-05-01

    This study developed a new method for the analysis of 20 phenolic compounds in human urine. The urine samples were prepared by hydrochloric acid (HCl) hydrolysis, liquid-liquid extraction (LLE), and solid-phase extraction (SPE) cleanup. We found that HCl hydrolysis is of similar effectiveness to, and much cheaper than, the traditional enzymatic method. Vanillic acid was co-eluted with butyl paraben and interfered with the determination of butyl paraben in urine. K2CO3-treated-silica-gel SPE was designed to efficiently eliminate interference from the endogenous organic acids (especially vanillic acid) in urine. After derivatization, the samples were analyzed by large-volume-injection gas chromatography-tandem mass spectrometry (LVI-GC-MS-MS). Good linearity (R (2) ≥ 0.996) was established in the range 0.1-100 ng mL(-1) for all analytes. Method detection limits (MDLs) were 0.7-9.8 pg mL(-1). Intraday (n = 5) and interday (n = 5 days) validation was performed, with satisfactory accuracy (recovery: 70-126 % and 73-107 %, respectively) and precision (RSD ≤ 19 %) at two levels (low: 0.1 and 0.5 ng mL(-1); high: 5 and 10 ng mL(-1)). The method was used in a population study and achieved more than 85 % detection for most analytes; mean analyte concentrations were in the range 0.01-185 ng mL(-1). The method is suitable for the analysis of multiple phenolic metabolites in human urine.

  15. 双酶水解蚕蛹蛋白制备氨基酸饮料的研究%Double Enzyme Hydrolysis Silkworm Chrysalis Protein Preparation Amino Acid Drink Research

    Institute of Scientific and Technical Information of China (English)

    于小磊; 耿丽晶; 郭雪松; 岳昊博

    2013-01-01

    为了充分利用蚕蛹资源,研究双酶水解蚕蛹蛋白的最佳条件,考察影响酶解效果的主要因素。确定了新鲜蚕蛹经漂烫、提脂、酶解、调配等工序制成蛋白饮料的工艺条件,消除了蚕蛹蛋白的褐变和凝沉现象。采用L9(33)正交试验设计方法,分别对酶解蚕蛹蛋白的温度、酶解时间、酶用量进行实验与结果分析,以确定双酶水解蚕蛹蛋白的最适条件。结果表明:最佳酶解条件为胰蛋白酶:pH 7.0,温度为45℃,酶解时间5 h,酶用量为1 g。木瓜蛋白酶:pH 6.0,温度为70℃,酶解时间4 h,酶用量为1 g。结论胰蛋白酶加入到木瓜蛋白酶酶解蚕蛹蛋白过程中,可使酶解液中氨态氮含量有明显的提高。经检验产品中细菌总数、大肠菌群、致病菌等指标符合相关食品卫生标准。氨基酸饮料中总糖(以蔗糖计)含量为14%,酸度(以柠檬酸计)含量为0.68 g/L,其产品符合饮料的理化检验及卫生指标。%In order to fully utilize the pupa resources, this article had studied the dual-pupa protein hydrolysis of the optimal conditions,determined the impact of the main factors enzyme effect. A fresh study by blanching chrysalis, to fat, enzyme, the deployment of processes such as protein drinks made from the process, eliminate the chrysalis of the Browning and condensate Shen phenomenon. By three factors and three levels orthogonal L9(33) Test methods, respectively, the pupa protein enzyme temperature, hydrolysis time, the amount of experiments and analysis, the double-pupa protein hydrolysis the optimum conditions. The results showed that:the best conditions for the enzyme trypsin: pH value of 7.0, the temperature of 45℃, hydrolysis time 5h, the amount of 1 g. Papain: pH value of 6.0, the temperature of 70℃, hydrolysis time 4 h, the amount of 1 g. Conclusion trypsin into the pupa protein enzyme papain process, will enable enzyme solution of ammonia

  16. Isolation and characterization of two forms of an acidic bromelain stem proteinase.

    Science.gov (United States)

    Harrach, T; Eckert, K; Maurer, H R; Machleidt, I; Machleidt, W; Nuck, R

    1998-05-01

    Two forms of an acidic bromelain proteinase isolated from crude bromelain, an extract from pineapple stem, were found by a two-step FPLC purification procedure. The basic main components were removed by cation exchange chromatography and the breakthrough fraction was further resolved by anion exchange chromatography into 15 protein fractions, only two of which, called SBA/a and SBA/b, were proteolytically active. These components were characterized by electrospray mass spectroscopy (ESMS), isoelectric focusing, N-terminal amino acid sequence analysis, monosaccharide analysis, and enzymatic parameters. The molecular masses of SBA/a and SBA/b were determined by ESMS to be 23,550 and 23,560, respectively. The isoelectric points (pI) of the two bands of SBA/a were 4.8 and 4.9; SBA/b focused as a single band at pI = 4.8. Partial N-terminal amino acid sequences (11 residues) were identical to SBA/a and SBA/b and identical with those of stem bromelain, the basic main proteinase of the pineapple stem, and fruit bromelain, the acidic main proteinase of the pineapple fruit. Both components are highly glycosylated; hydrolysis of SBA/a yielded about twofold more monosaccharide per protein than SBA/b. The comparison of the catalytic properties of SBA/a with those of SBA/b revealed no relevant differences in the hydrolysis of three peptidyl-NH-Mec substrates and in the inhibition profiles using chicken cystatin and E-64, indicating that these components can be considered as two forms of a single enzyme. Both forms are scarcely inhibited by chicken cystatin and slowly inactivated by E-64, hence are nontypical cysteine proteinases of the papain superfamily.

  17. 5-hydroxymethyl-2-furfural and derivatives formed during acid hydrolysis of conjugated and bound phenolics in plant foods and the effects on phenolic content and antioxidant capacity.

    Science.gov (United States)

    Chen, Peter X; Tang, Yao; Zhang, Bing; Liu, Ronghua; Marcone, Massimo F; Li, Xihong; Tsao, Rong

    2014-05-21

    A common protocol for the extraction of phenolic aglycons or bound phenolics in plants generally involves hydrothermal hydrolysis in an aqueous methanol or ethanol solution containing 2-4 N HCl. However, as shown in the present study, this process also forms 5-(hydroxymethyl)furan-2-carbaldehyde (HMF) and its derivative products 5-(methoxymethyl)furan-2-carbaldehyde (MMF) and 5-(ethoxymethyl)furan-2-carbaldehyde (EMF), as identified by HPLC-DAD-ESI-MS/MS and NMR. These compounds are commonly misidentified as phenolics due to similar UV absorption at 280 nm. In this study, production of HMF, MMF, and EMF was shown to be dependent on the solvent condition and duration and temperature of hydrolysis. Fruits and vegetables produced HMF more readily than grains. HMF and its derivatives were subjected to various spectrophotometric antioxidant assays [2-diphenyl-1-picryhydrazyl radical scavenging activity (DPPH), ferric-reducing antioxidant power (FRAP), and oxygen radical absorbing capacity (ORAC)] and displayed antioxidant activity mainly in the ORAC assay. Results of this study help avoid overestimation of phenolic content and antioxidant activities of plant foods.

  18. Monosaccharide-responsive phenylboronate-polyol cell scaffolds for cell sheet and tissue engineering applications.

    Directory of Open Access Journals (Sweden)

    Rachamalla Maheedhar Reddy

    Full Text Available Analyte-responsive smart polymeric materials are of great interest and have been actively investigated in the field of regenerative medicine. Phenylboronate containing copolymers form gels with polyols under alkaline conditions. Monosaccharides, by virtue of their higher affinity towards boronate, can displace polyols and solubilize such gels. In the present study, we investigate the possibility of utilizing phenylboronate-polyol interactions at physiological pH in order to develop monosaccharide-responsive degradable scaffold materials for systems dealing with cells and tissues. Amine assisted phenylboronate-polyol interactions were employed to develop novel hydrogel and cryogel scaffolds at neutral pH. The scaffolds displayed monosaccharide inducible gel-sol phase transformability. In vitro cell culture studies demonstrated the ability of scaffolds to support cell adhesion, viability and proliferation. Fructose induced gel degradation is used to recover cells cultured on the hydrogels. The cryogels displayed open macroporous structure and superior mechanical properties. These novel phase transformable phenylboronate-polyol based scaffolds displayed a great potential for various cell sheet and tissue engineering applications. Their monosaccharide responsiveness at physiological pH is very useful and can be utilized in the fields of cell immobilization, spheroid culture, saccharide recognition and analyte-responsive drug delivery.

  19. Direct imaging of glycans in Arabidopsis roots via click labeling of metabolically incorporated azido-monosaccharides.

    Science.gov (United States)

    Hoogenboom, Jorin; Berghuis, Nathalja; Cramer, Dario; Geurts, Rene; Zuilhof, Han; Wennekes, Tom

    2016-10-10

    Carbohydrates, also called glycans, play a crucial but not fully understood role in plant health and development. The non-template driven formation of glycans makes it impossible to image them in vivo with genetically encoded fluorescent tags and related molecular biology approaches. A solution to this problem is the use of tailor-made glycan analogs that are metabolically incorporated by the plant into its glycans. These metabolically incorporated probes can be visualized, but techniques documented so far use toxic copper-catalyzed labeling. To further expand our knowledge of plant glycobiology by direct imaging of its glycans via this method, there is need for novel click-compatible glycan analogs for plants that can be bioorthogonally labelled via copper-free techniques. Arabidopsis seedlings were incubated with azido-containing monosaccharide analogs of N-acetylglucosamine, N-acetylgalactosamine, L-fucose, and L-arabinofuranose. These azido-monosaccharides were metabolically incorporated in plant cell wall glycans of Arabidopsis seedlings. Control experiments indicated active metabolic incorporation of the azido-monosaccharide analogs into glycans rather than through non-specific absorption of the glycan analogs onto the plant cell wall. Successful copper-free labeling reactions were performed, namely an inverse-electron demand Diels-Alder cycloaddition reaction using an incorporated N-acetylglucosamine analog, and a strain-promoted azide-alkyne click reaction. All evaluated azido-monosaccharide analogs were observed to be non-toxic at the used concentrations under normal growth conditions. Our results for the metabolic incorporation and fluorescent labeling of these azido-monosaccharide analogs expand the possibilities for studying plant glycans by direct imaging. Overall we successfully evaluated five azido-monosaccharide analogs for their ability to be metabolically incorporated in Arabidopsis roots and their imaging after fluorescent labeling. This expands

  20. Bagasse hydrolyzates from Agave tequilana as substrates for succinic acid production by Actinobacillus succinogenes in batch and repeated batch reactor.

    Science.gov (United States)

    Corona-González, Rosa Isela; Varela-Almanza, Karla María; Arriola-Guevara, Enrique; Martínez-Gómez, Álvaro de Jesús; Pelayo-Ortiz, Carlos; Toriz, Guillermo

    2016-04-01

    The aim of this work was to obtain fermentable sugars by enzymatic or acid hydrolyses of Agave tequilana Weber bagasse in order to produce succinic acid with Actinobacillus succinogenes. Hydrolyses were carried out with mineral acids (sulfuric and hydrochloric acids) or a commercial cellulolytic enzyme, and were optimized statistically by a response surface methodology, having as factors the concentration of acid/enzyme and time of hydrolysis. The concentration of sugars obtained at optimal conditions for each hydrolysis were 21.7, 22.4y 19.8g/L for H2SO4, HCl and the enzymatic preparation respectively. Concerning succinic acid production, the enzymatic hydrolyzates resulted in the highest yield (0.446g/g) and productivity (0.57g/Lh) using A. succinogenes in a batch reactor system. Repeated batch fermentation with immobilized A. succinogenes in agar and with the enzymatic hydrolyzates resulted in a maximum concentration of succinic acid of 33.6g/L from 87.2g/L monosaccharides after 5 cycles in 40h, obtaining a productivity of 1.32g/Lh.

  1. 微波固体酸联合水解棉籽壳制备还原糖的研究%Preparation of reducing sugar via synergistic hydrolysis cotton seed hull with microwave and solid acid

    Institute of Scientific and Technical Information of China (English)

    余先纯; 孙德林; 李湘苏

    2011-01-01

    以棉籽壳为原料,采用微波和固体酸协同水解制备还原糖.探讨了微波功率、固体酸用量、反应时间、反应温度、液固比对还原性糖得卒的影响.采用响应面法建立二次回归模型,并对水解工艺进行了优化.研究结果表明,当 微波功率461.91W,固体酸用量6.46%,反应时间2.99h,反应温度100℃,液固比为18:1时,还原糖的得率可达到62.49%.%Reducing sugar was made from cotton seed hull via synergistic hydrolysis with microwave and solid acid. The effects of microwave power, amount of solid acid, hydrolysis time, temperature and liquid-solid mass ratios on the reducing sugar yield were discussed. A quadratic regression model was founded with response surface methodology,and the process was optimized. The result showed that the reducing sugar yield was 62.49% as the microwave power was 461.91W, amaunt of solid acid was 6.46%,time was 2.99h,temperature was 100℃,liquid-solid mass ratios was 18:1.

  2. 积雪草皂苷酸水解产物中1个新苷元的分离和鉴定%Isolation and idetification of a new aglycone from acid hydrolysis products of saponin in Centella asiatica

    Institute of Scientific and Technical Information of China (English)

    曹家庆; 周康; 时圣明; 赵余庆

    2016-01-01

    Objective To study the chemical constituents of the acid hydrolysis products,in order to find some new aglycones from the hydrolysate of the saponin of Centella asiatica.Methods The acid hydrolytic product was separated by repeated silica gel,Sephadex LH-20 chromatography.The cytotoxic activities in vitro of some compounds isolated were evaluated.Their structures isolated were identified by analysis of their spectral data of NMR,MS,IR,and UV.Results Four aglycones,2α,3β,23-trihydroxyurs-6,12-dien-28-oic acid (1),asiatic acid (2),6β-hydroxy asiatic acid (3),terrninolic acid (4),were isolated from the hydrolysis product.Conclusions Compound 1,named centella-6-ene,was a new ursane-type aglycone and it showed no cytotoxic activities against the tested cancer cell lines.%目的 研究积雪草Centella asiatica皂苷水解产物的化学成分,以期发现新的三萜皂苷元.方法 通过硅胶、凝胶柱色谱对积雪草皂苷酸水解产物进行分离,经核磁共振、质谱、红外光谱、紫外光谱等波谱手段对化合物的结构进行鉴定.并对部分化合物的体外抗肿瘤活性进行了测试.结果 从积雪草皂苷酸水解产物中分离得到4个单体苷元化合物,鉴定为2α,3β,23-三羟基乌苏-6,12-二烯-28-酸(1)、积雪草酸(2)、6β-羟基积雪草酸(3)、terminolic acid (4).结论 化合物1为1个新的乌苏烷型苷元,命名为积雪草-6-烯,并且其对所测试的肿瘤细胞HL-60、A549、U873无抑制活性.

  3. Hydrolysis of lactose: a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Gekas, V.; Lopez-Leiva, M.

    1985-02-01

    Lactose is the sugar found in milk and whey. Its hydrolysis to glucose and galactose in milk would solve the problem of milk-intolerant people and in whey it would avoid environmental pollution and offer an interesting possibility of by-product utilization. The prepared sweet syrup has many potential applications in the food industry. Hydrolysis of lactose can be carried out by heating at low pH (acid hydrolysis) or by enzymatic catalysis with the enzyme (lactase or ..beta..-D-galactosidase) either free in solution or immobilized by one of the several enzyme immobilization methods which are abundant in the literature. Selection of the proper method depends on many factors: the nature of substrate, use of the final product, need for sanitary conditions, and, of course, capital and processing costs. 157 references.

  4. 酸性离子液体[bmim]HSO4催化纤维素水解的研究%Hydrolysis of Cellulose Catalyzed by Acidic Ionic Liquid [bmim] HSO4

    Institute of Scientific and Technical Information of China (English)

    芦天亮; 秦志芳; 唐思; 周利鹏; 苏运来; 杨晓梅

    2012-01-01

    Hydrolysis of cellulose was carried out in l-n-butyl-3-methylimidazolium chloride catalyzed by acidic ionic liquid l-n-butyl-3-methylimidazolium hydrogen sulfate ( [ bmim] HSO4 ) . Reaction results showed that these parameters including the pre-dissolving time for cellulose, the reaction temperature, the amount of catalyst and water remarkably affected the hydrolysis of cellulose to the reduced sugar. Ninety two percent yield of reduced sugar was obtained by 1.5 g of catalyst and 0. 1 mL of water at 90℃ with 80 min of reaction time.%以1-正丁基-3-甲基氯代咪唑为溶剂,酸性离子液体1-正丁基-3-甲基硫酸氢根代咪唑([bmim] HSO4)为催化剂,考察了溶解时间、反应温度、催化剂用量、水量等因素对纤维素水解的影响.结果表明,[bmim] HSO4具有良好的催化效果,当催化剂用量为1.5 g,水量为0.1 mL,反应温度为90℃时,反应80 min,还原糖收率可以达到92%.

  5. 氮杂冠醚化双Schiff碱配合物催化羧酸酯水解的研究%Study on aza crown ether substituted bis-Schiff base complexes catalyze carboxylic acid esters hydrolysis

    Institute of Scientific and Technical Information of China (English)

    程杰; 李建章; 何锡阳; 曾俊; 肖正华; 胡伟

    2012-01-01

    将4种氮杂冠醚取代的双Schiff碱钴(H)、锰(m)配合物作为仿水解酶模型催化羧酸酯(PNPP)水解.考察了Schiff碱配合物中氮杂冠醚取代的位置、氮杂冠醚的数目对其仿水解酶性能的影响;探讨了Schiff配合物催化PNPP水解的动力学和机理;提出了配合物催化PNPP水解的动力学模型.结果表明,在25℃条件下随着缓冲溶液pH值的增大,配合物催化PNPP水解速率提高;四种氮杂冠醚取代的双Schiff碱配合物在催化PNPP水解反应中表现出良好的催化活性;氮杂冠醚3-取代的Schiff碱配合物CoL2的催化活性高于5-取代的Schiff碱配合物CoL1,含有2个氮杂冠醚的配合物CoL3的催化活性高于含有1个氮杂冠醚的配合物CoL2.%Four aza crown ether substituted bis-Schiff base transition-mental complexes have been used as mimic hydrolytic enzyme model catalyzing carboxylic acid esters ( PNPP) hydrolysis. The effects of substituted position of aza-crown and amount of aza-crown of Schiff base complexes were studied. The kinetics on PNPP hydrolysis catalyzed by these complexes was investigated. The kinetic mathematical model of PNPP cleavage catalyzed by these complexes was proposed. The results showed that the rate for the catalytic PNPP hydrolysis was increased following the increase of pH of the buffer solution; four complexes exhibited high activity in the catalytic PNPP hydrolysis, The catalytic activity of unsymmetrical Schiff base complexes of 3-substitute benzo-10-aza-crown groups ( CoL2 ) is larger than that of 5 -substitute benzo-10-aza-crown groups ( CoL1) , and the catalytic activity of Schiff base complexes with two benzo-10-aza-crown ether pendants (CoL3) is larger than that of Schiff base complexes with one benzo-10-aza-crown ether pendants (CoL2).

  6. ENZYMATIC HYDROLYSIS OF STARCH

    OpenAIRE

    Reyna M., L.; Facultad de Química e ingeniería Química, Universidad Nacional Mayor de San Marcos. Lima-Perú; Robles, R.; Facultad de Química e ingeniería Química, Universidad Nacional Mayor de San Marcos. Lima-Perú; Reyes P., M.; Facultad de Química e ingeniería Química, Universidad Nacional Mayor de San Marcos. Lima-Perú; Mendoza R., Y.; Facultad de Química e ingeniería Química, Universidad Nacional Mayor de San Marcos. Lima-Perú; Romero D., J.; Facultad de Química e ingeniería Química, Universidad Nacional Mayor de San Marcos. Lima-Perú

    2014-01-01

    We obtained rate constant for enzymatic hydrolysis of barley at temperature of 70 ºC. Se ha llevado a cabo la hidrólisis enzimática de la cebada a 70 ºC y se determinó la constante cinética de reacción.

  7. Accelerated hydrolysis of substituted cellulose for potential biofuel production: kinetic study and modeling.

    Science.gov (United States)

    Mu, Bingnan; Xu, Helan; Yang, Yiqi

    2015-11-01

    In this work, kinetics of substitution accelerated cellulose hydrolysis with multiple reaction stages was investigated to lay foundation for mechanism study and molecular design of substituting compounds. High-efficiency hydrolysis of cellulose is critical for cellulose-based bioethanol production. It is known that, substitution could substantially decrease activation energy and increase reaction rate of acidic hydrolysis of glycosidic bonds in cellulose. However, reaction kinetics and mechanism of the accelerated hydrolysis were not fully revealed. In this research, it was proved that substitution therefore accelerated hydrolysis only occurred in amorphous regions of cellulose fibers, and was a process with multiple reaction stages. With molar ratio of substitution less than 1%, the overall hydrolysis rate could be increased for around 10 times. We also quantified the relationship between the hydrolysis rate of individual reaction stage and its major influences, including molar ratio of substitution, activation energy of acidic hydrolysis, pH and temperature. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Linear polyethylenimine produced by partial acid hydrolysis of poly(2-ethyl-2-oxazoline for DNA and siRNA delivery in vitro

    Directory of Open Access Journals (Sweden)

    Fernandes JC

    2013-10-01

    Full Text Available Julio C Fernandes,1 Xingping Qiu,2 Françoise M Winnik,2,5 Mohamed Benderdour,1 Xiaoling Zhang,3,4 Kerong Dai,3,4 Qin Shi1 1Orthopaedics Research Laboratory, Research Centre, Sacré-Coeur Hospital, 2Faculty of Pharmacy and Chemistry, University of Montreal, Montreal, Quebec, Canada; 3Orthopaedic Cellular and Molecular Biology Laboratories, Institute of Health Sciences, Chinese Academy of Sciences, 4Department of Orthopaedics, Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, People's Republic of China; 5WPI International Center for Materials Nanoarchitectonics, National Institute for Materials Science, Ibaraki, Tsukuba, Japan Abstract: Polyethylenimines (PEIs are the most efficient synthetic vectors for gene delivery available to date. With its high charge density and strong proton-buffering effect, PEI has an ability to condense DNA and small interfering RNA at physiologic pH. However, the polymer suffers from the disadvantage of high cellular toxicity. To reduce its cellular toxicity, we synthesized linear PEIs by partial hydrolysis of poly(2-ethyl-2-oxazoline. Three linear PEIs with different hydrolysis percentages (30%, 70%, and 96%, respectively were produced as PEI30, PEI70, and PEI96. PEI30 and PEI96 cannot be considered as suitable transfection agents because of low transfection efficiency (PEI30 or high cellular toxicity (PEI96. PEI70 displayed very weak cell toxicity. The charge density of this polymer (PEI70 was strong enough to condense DNA and small interfering RNA at a physiologic pH of 7.4. Our results also show that PEI70 was highly efficient in DNA delivery and small interfering RNA-mediated knockdown of target genes. Thus, polymers such as PEI70 appear to be very promising vectors for gene delivery. Keywords: nonviral vector, polyethylenimine, gene delivery, DNA, small interfering RNA

  9. Selective enzymatic hydrolysis of chlorogenic acid lactones in a model system and in a coffee extract. Application to reduction of coffee bitterness.

    Science.gov (United States)

    Kraehenbuehl, Karin; Page-Zoerkler, Nicole; Mauroux, Olivier; Gartenmann, Karin; Blank, Imre; Bel-Rhlid, Rachid

    2017-03-01

    Chlorogenic acid lactones have been identified as key contributors to coffee bitterness. These compounds are formed during roasting by dehydration and cyclization of their precursors, the chlorogenic acids (CGAs). In the present study, we investigated an approach to decompose these lactones in a selective way without affecting the positive coffee attributes developed during roasting. A model system composed of (3-caffeoylquinic acid lactone (3-CQAL), 4- caffeoyl quinic acid lactone (4-CQAL), and 4-feruloylquinic acid lactone (4-FQAL)) was used for the screening of enzymes before treatment of the coffee extracts. Hog liver esterase (HLE) hydrolyzed chlorogenic acid lactones (CQALs, FQALs) selectively, while chlorogenate esterase hydrolyzed all chlorogenic acids (CQAs, FQAs) and their corresponding lactones (CQALs, FQALs) in a non-selective way. Enzymatically treated coffee samples were evaluated for their bitterness by a trained sensory panel and were found significantly less bitter than the untreated samples.

  10. delta 13C analyses of vegetable oil fatty acid components, determined by gas chromatography--combustion--isotope ratio mass spectrometry, after saponification or regiospecific hydrolysis.

    Science.gov (United States)

    Woodbury, S E; Evershed, R P; Rossell, J B

    1998-05-01

    The delta 13C values of the major fatty acids of several different commercially important vegetable oils were measured by gas chromatography--combustion--isotope ratio mass spectrometry. The delta 13C values obtained were found to fall into two distinct groups, representing the C3 and C4 plants classes from which the oils were derived. The delta 13C values of the oils were measured by continuous flow elemental isotope ratio mass spectrometry and were found to be similar to their fatty acids, with slight differences between individual fatty acids. Investigations were then made into the influence on the delta 13C values of fatty acids of the position occupied on the glycerol backbone. Pancreatic lipase was employed to selectively hydrolyse fatty acids from the 1- and 3-positions with the progress of the reaction being followed by high-temperature gas chromatography in order to determine the optimum incubation time. The 2-monoacylglycerols were then isolated by thin-layer chromatography and fatty acid methyl esters prepared. The delta 13C values obtained indicate that fatty acids from any position on the glycerol backbone are isotopically identical. Thus, whilst quantification of fatty acid composition at the 2-position and measurement of delta 13C values of oils and their major fatty acids are useful criteria in edible oil purity assessment, measurement of delta 13C values of fatty acids from the 2-position does not assist with oil purity assignments.

  11. Enzymatic Hydrolysis of Lignocelluloses

    DEFF Research Database (Denmark)

    Kolasa, Marta; Ahring, Birgitte Kiær; Lübeck, Peter Stephensen

    2010-01-01

    bonds. Cellulose can be degraded to simple sugar components by means of enzymatic hydrolysis. However, due to its complex, crystalline structure it is difficult to break it down and the cooperative action of a variety of cellulolytic enzymes is necessary. Fungi are known to have potential in production......Lignocellulosic materials form a huge part of the plant biomass from agricultural and forestry wastes. They consist of three major components: cellulose, hemicellulose and lignin. Cellulose, the main constituent of plant cell wall, is a polymer of D–glucopyranose units linked by β-1,4-glucosidic...... of a variety of cellulolytic enzymes. The aim of this work is to discover new thermostable and robust cellulolytic enzymes for improved enzymatic hydrolysis of biomass. For this purpose two screening methods are applied in different fungal strains with high cellulolytic activities: an expression–based method...

  12. Optimizing the acid hydrolysis process of bagasse nanocrystalline cellulose via the surface response method%甘蔗渣纳晶纤维素酸法制备工艺的响应面法优化

    Institute of Scientific and Technical Information of China (English)

    李春光; 彭伟功; 许可; 王香平; 田魏

    2012-01-01

    In this paper, we would like to introduce a new approach to optimizing the acid hydrolysis process of bagasse nanocrystalline cellulose via the surface response method. As is known, nanocrystalline cellulose enjoys a lot of marvelous behaviors, which make it widely used in the field of food processing, papermaking, environmental protection and renewable medical materials, and so on. However , due to the high cost of nanoerystalline cellulose preparation, its application in industrial fields remains severely restricted. As a major byproduct of the sugar industry, bagasse contains a lot of cellulose, lignin, hemicellulose and other natural polymer substances. If the cellulose of bagasse can be successfully extracted with nanocrystalline cellulose, huge economic and environmental benefits will be brought about to enrich our life and industrial production. It is for this urgent need that we have made great endeavors to explore potential for utilizing bagasse nanocrystalline cellulose and improve on the processing conditions for its future development. Based on the Box-Behnken design, we have studied and chosen sulfuric acid mass fraction, hy-drolytic temperature and hydrolytic time as the three key factors at the five levels. Furthermore, we have optimized the process conditions of bagasse nanocrystalline cellulose by using acid hydrolysis and response surface methodology, and worked out a mathematical model of a second order quadratic equation for the yield of nanocrystalline cellulose . The regression coefficient and variance analysis prove that the regression model is fit for the relationship of bagasse nanocrystalline cellulose yield and sulfuric acid mass fraction, the hydrolytic temperature and hydrolytic time. And, finally, we have managed to optimize the following technological parameters: the maintenance sulfuric acid mass fraction (56% ), the hydrolytic time (180 min) , the hydrolytic temperature (38 ℃ ) , the yield of bagasse nanocrystalline cellulose that

  13. Acid Hydrolysis of Wheat Gluten Induces Formation of New Epitopes but Does Not Enhance Sensitizing Capacity by the Oral Route: A Study in “Gluten Free” Brown Norway Rats

    DEFF Research Database (Denmark)

    Kroghsbo, Stine; Andersen, Nanna Birch; Rasmussen, Tina Frid

    2014-01-01

    the sensitizing capacity of gluten proteins per se when altered by acid or enzymatic hydrolysis relative to unmodified gluten in rats naïve to gluten. Methods High IgE-responder Brown Norway (BN) rats bred on a gluten-free diet were sensitized without the use of adjuvant to three different gluten products...... (unmodified, acid hydrolyzed and enzymatic hydrolyzed). Rats were sensitized by intraperitoneal (i.p.) immunization three times with 200 µg gluten protein/rat or by oral dosing for 35 days with 0.2, 2 or 20 mg gluten protein/rat/day. Sera were analyzed for specific IgG and IgE and IgG-binding capacity...... by ELISA. IgE functionality was measured by rat basophilic leukemia (RBL) assay. Results Regardless of the route of dosing, all products had sensitizing capacity. When sensitized i.p., all three gluten products induced a strong IgG1 response in all animals. Acid hydrolyzed gluten induced the highest level...

  14. pH对油酸水解废水酸化发酵过程的影响%Effect of pH on the Acidification Fermentation Process in Oleic Acid Hydrolysis Wastewater

    Institute of Scientific and Technical Information of China (English)

    吴九九; 刘建平; 杨春燕

    2012-01-01

    pH对油酸水解废水酸化发酵影响的研究表明,pH不仅对酸化速率有很大影响,而且也会影响酸化产物的构成;不同pH值下酸化的主要产物是乙酸,但酸化的最佳pH值为6.5,此pH条件下VFA的产量最高可达12.53 g/L;在pH〉7时,明显有丙酸生成。%The impact of pH on the environment of acidification fermentation in oleic acid hydrolysis wastewater is studied, and the results show that pH has a great influence not only on the rate of acidi- fication ,but also on the composition of acidification products. The chief product of acidification is acetic acid under different pH value. The most favorable pH value in acidification is 6.5, at which the highest yielding of VFA ( 12.53 g/L) was obtained. The formation of propionic acid is apparent when pH 〉 7.

  15. Dilute sulfuric acid pretreatment of corn stover for enzymatic hydrolysis and efficient ethanol production by recombinant Escherichia coli FBR5 without detoxification.

    Science.gov (United States)

    Avci, Ayse; Saha, Badal C; Kennedy, Gregory J; Cotta, Michael A

    2013-08-01

    A pretreatment strategy for dilute H2SO4 pretreatment of corn stover was developed for the purpose of reducing the generation of inhibitory substances during pretreatment so that a detoxification step is not required prior to fermentation while maximizing sugar yield. The optimal conditions for pretreatment of corn stover (10%, w/v) were: 0.75% H2SO4, 160°C, and 0-5 min holding time. The conditions were chosen based on maximum glucose release after enzymatic hydrolysis, minimum loss of pentose sugars and minimum formation of sugar degradation products such as furfural and hydroxymethyl furfural. The pretreated corn stover after enzymatic saccharification generated 63.2 ± 2.2 and 63.7 ± 2.3 g total sugars per L at 0 and 5 min holding time, respectively. Furfural production was 0.45 ± 0.1 and 0.87 ± 0.4 g/L, respectively. The recombinant Escherichia coli strain FBR5 efficiently fermented non-detoxified corn stover hydrolyzate if the furfural content is <0.5 g/L.

  16. NREL 2012 Achievement of Ethanol Cost Targets: Biochemical Ethanol Fermentation via Dilute-Acid Pretreatment and Enzymatic Hydrolysis of Corn Stover

    Energy Technology Data Exchange (ETDEWEB)

    Tao, L.; Schell, D.; Davis, R.; Tan, E.; Elander, R.; Bratis, A.

    2014-04-01

    For the DOE Bioenergy Technologies Office, the annual State of Technology (SOT) assessment is an essential activity for quantifying the benefits of biochemical platform research. This assessment has historically allowed the impact of research progress achieved through targeted Bioenergy Technologies Office funding to be quantified in terms of economic improvements within the context of a fully integrated cellulosic ethanol production process. As such, progress toward the ultimate 2012 goal of demonstrating cost-competitive cellulosic ethanol technology can be tracked. With an assumed feedstock cost for corn stover of $58.50/ton this target has historically been set at $1.41/gal ethanol for conversion costs only (exclusive of feedstock) and $2.15/gal total production cost (inclusive of feedstock) or minimum ethanol selling price (MESP). This year, fully integrated cellulosic ethanol production data generated by National Renewable Energy Laboratory (NREL) researchers in their Integrated Biorefinery Research Facility (IBRF) successfully demonstrated performance commensurate with both the FY 2012 SOT MESP target of $2.15/gal (2007$, $58.50/ton feedstock cost) and the conversion target of $1.41/gal through core research and process improvements in pretreatment, enzymatic hydrolysis, and fermentation.

  17. Pretreating lignocellulosic biomass by the concentrated phosphoric acid plus hydrogen peroxide (PHP) for enzymatic hydrolysis: evaluating the pretreatment flexibility on feedstocks and particle sizes.

    Science.gov (United States)

    Wang, Qing; Wang, Zhanghong; Shen, Fei; Hu, Jinguang; Sun, Fubao; Lin, Lili; Yang, Gang; Zhang, Yanzong; Deng, Shihuai

    2014-08-01

    In order to seek a high-efficient pretreatment path for converting lignocellulosic feedstocks to fermentable sugars by enzymatic hydrolysis, the concentrated H₃PO₄ plus H₂O₂ (PHP) was attempted to pretreat different lignocellulosic biomass for evaluating the pretreatment flexibility on feedstocks. Meanwhile, the responses of pretreatment to particle sizes were also evaluated. When the PHP-pretreatment was employed (final H₂O₂ and H₃PO₄ concentration of 1.77% and 80.0%), 71-96% lignin and more than 95% hemicellulose in various feedstocks (agricultural residues, hardwood, softwood, bamboo, and their mixture, and garden wastes mixture) can be removed. Consequently, more than 90% glucose conversion was uniformly achieved indicating PHP greatly improved the pretreatment flexibility to different feedstocks. Moreover, when wheat straw and oak chips were PHP-pretreated with different sizes, the average glucose conversion reached 94.9% and 100% with lower coefficient of variation (7.9% and 0.0%), which implied PHP-pretreatment can significantly weaken the negative effects of feedstock sizes on subsequent conversion.

  18. Combined enzymatic starch hydrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Nebesny, E.

    1989-07-01

    From researches so far there comes out that glucoamylase AMG 300 L and pullulanase Promozyme 200 L when used in quantities the same as in preparation of Dextrozyme 225/75 L Novo at an action on liquified starch by means of /alpha/-amylase after 48 h of saccharification already (similarly like Dextrozyme) are able to get up to 98 DE. Chromatographic analysis proved that glucoamylase AMG 300 L Novo and succouring it pullulanase Promozyme 200 L are working most effectively when both enzymes are added to the liquified starch medium simultaneously. From this comes out that pullulanase hydrolyzes better /alpha/-1,6 bonds in lowmolecular dextrins than in oligosaccharides G/sub 4/ to G/sub 7/ formed at previous action of glucoamylase. At an optimum ratio of glucoamylase and pullulanase in relation to the dissolved starch after 8 h of the hydrolysis there are neither iso-sugars (isomaltose, panose), no oligosaccharides higher than G/sub 5/ and no dextrins. At the solution of the starch by /alpha/-amylase and its hydrolysis by enzymatic preparation Fungamyl 800 L Novo, at doses 0.02-0.8% to d.s. of starch, already after 8 h the reaction of hydrolysis contents of 36-62% maltose in dry substance of hydrolyzates are reached with only traces of glucose. (orig.).

  19. Effect of monosaccharides and ethyleneglycol on the interaction between Escherichia coli bacteria and Octyl-Sepharose.

    Science.gov (United States)

    Ohman, L; Magnusson, K E; Stendahl, O

    1985-04-01

    Combined effects of monosaccharides and reduced surface tension of the medium were studied in relation to the hydrophobic binding of Escherichia coli bacteria, with and without mannose-specific structures. Hydrophobic binding was analyzed by hydrophobic interaction chromatography on Octyl-Sepharose. The results showed that ethyleneglycol, as well as mannose, reduced the hydrophobic interaction of the bacteria with mannose-specific structures. This effect was potentiated by combining ethyleneglycol and mannose. No other monosaccharides tested (galactose and fucose) had any effect on the hydrophobic interaction of bacteria with mannose-specific structures. These results further strengthen the hypothesis that the mannose-specific interaction of Escherichia coli bacteria is, at least in part, mediated by hydrophobic forces.

  20. Analysis of Monosaccharide Composition of Pu-erh Tea Polysaccaride by Pre-column Derivatization HPLC%柱前衍生HPLC法分析普洱茶多糖中单糖组成

    Institute of Scientific and Technical Information of China (English)

    郭威; 周斌星; 罗玲; 李扬; 柴洁; 杨超; 马存强

    2013-01-01

    [Objective] This study aimed to establish a pre-column derivatization HPLC method for the identification and analysis of monosaccharide composition of Pu-erh tea polysaccharide.[Method] Pu-erh tea polysaccharide was extracted using the water extraction method,further isolated and purified by DEAE cellulose-52 columns.The obtained tea polysaccharide and four components TPS1,TPS2,TPS3 and TPS4 were first derived by 1-phenyl-3-methyl-5-pyrazolone (PMP),and then the PMP derivatives of monosaccharide were analyzed by high performance liquid chromatography (HPLC).[Result] Pu-erh tea polysaccharide contained eight kinds of monosac-charides (mannose,rhamnose,glucuronic acid,galacturonic acid,glucose,galactose,arabinose,fucose),without xylose; so it was the same with TPS1; each of TPS2,TPS3 and TPS4 contained seven monosaccharides,while no fucose.[Conclusion]This method is simplified and rapid,which can be used to determine the monosac-charide composition of Pu-erh tea polysaccharide and monosaccharide content.%[目的]建立柱前衍生HPLC法鉴别和分析普洱茶多糖中单糖组成.[方法]采用水提法提取普洱茶多糖,经DEAE Cellulose-52纤维素柱分离纯化;茶多糖及其组分TPS1、TPS2、TPS3、TPS4经1-苯基-3-甲基-5-吡唑啉酮(PMP)衍生化后,利用高效液相色谱法,分析单糖的PMP衍生物.[结果]普洱茶多糖中含有甘露糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸、葡萄糖、半乳糖、阿拉伯糖、岩藻糖8种单糖,不含有木糖;TPS1中含有全部8种单糖;TPS2、TPS3和TPS4均由7种单糖组成,且都不含岩藻糖.[结论]此方法简便,快速;可用于测定普洱茶多糖中单糖的组成分析和含量测定.